U.S. patent application number 13/563853 was filed with the patent office on 2012-11-22 for processing method of lithographic printing plate preursor.
This patent application is currently assigned to FUJIFILM Corporation. Invention is credited to Keiichi ADACHI, Shigekatsu Fujii, Takashi Sato, Yoshinori Taguchi.
Application Number | 20120295204 13/563853 |
Document ID | / |
Family ID | 40090116 |
Filed Date | 2012-11-22 |
United States Patent
Application |
20120295204 |
Kind Code |
A1 |
ADACHI; Keiichi ; et
al. |
November 22, 2012 |
PROCESSING METHOD OF LITHOGRAPHIC PRINTING PLATE PREURSOR
Abstract
A processing method of a lithographic printing plate precursor
includes: exposing imagewise a lithographic printing plate
precursor comprising a support on a surface of which at least one
of: a hydrophilizing treatment; and an undercoat layer has been
provided and an image-recording layer, to cure an exposed area of
the image-recording layer; and undergoing developing processing
with an aqueous solution having pH of from 2 to 10, wherein the
aqueous solution comprises an amphoteric surfactant and an anionic
surfactant selected from an anionic surfactant having an aliphatic
chain and a total number of carbon atoms included in the aliphatic
chain of 6 or more and an anionic surfactant having an aromatic
ring and a total number of carbon atoms of 12 or more, and a
content of the anionic surfactant is from 0.1 to 3.3% by weight of
the aqueous solution.
Inventors: |
ADACHI; Keiichi; (Shizuoka,
JP) ; Fujii; Shigekatsu; (Shizuoka, JP) ;
Taguchi; Yoshinori; (Shizuoka, JP) ; Sato;
Takashi; (Shizuoka, JP) |
Assignee: |
FUJIFILM Corporation
Tokyo
JP
|
Family ID: |
40090116 |
Appl. No.: |
13/563853 |
Filed: |
August 1, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12239035 |
Sep 26, 2008 |
8257913 |
|
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13563853 |
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Current U.S.
Class: |
430/302 |
Current CPC
Class: |
B41C 2210/06 20130101;
B41C 2201/04 20130101; B41C 2210/22 20130101; B41C 2210/20
20130101; B41C 1/1008 20130101; B41C 2210/04 20130101; B41C 2201/12
20130101; B41C 2201/02 20130101; B41C 2210/24 20130101; B41C
2201/14 20130101; B41C 2201/10 20130101; B41C 1/1016 20130101; B41N
3/08 20130101; G03F 7/322 20130101; B41C 2210/10 20130101 |
Class at
Publication: |
430/302 |
International
Class: |
G03F 7/20 20060101
G03F007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2007 |
JP |
2007-256706 |
Claims
1. A processing method of a lithographic printing plate precursor
comprising: exposing imagewise a lithographic printing plate
precursor comprising a support on a surface of which at least one
of: a hydrophilizing treatment; and an undercoat layer has been
provided and an image-recording layer, to cure an exposed area of
the image-recording layer; and undergoing developing processing
with an aqueous solution having pH of from 2 to 10, wherein the
aqueous solution comprises an amphoteric surfactant and an anionic
surfactant selected from an anionic surfactant having an aliphatic
chain and a total number of carbon atoms included in the aliphatic
chain of 6 or more and an anionic surfactant having an aromatic
ring and a total number of carbon atoms of 12 or more, and a
content of the anionic surfactant is from 0.1 to 3.3% by weight of
the aqueous solution, and wherein the image-recording layer
comprises a binder polymer, a polymerizable compound and a
polymerization initiator.
2. The processing method of a lithographic printing plate precursor
as claimed in claim 1, wherein the undercoat layer comprises an
acid group or a salt of an acid.
3. The processing method of a lithographic printing plate precursor
as claimed in claim 2, wherein the acid group is a sulfonic acid
group.
4. The processing method of a lithographic printing plate precursor
as claimed in claim 3, wherein the binder polymer comprises an
onium group.
5. The processing method of a lithographic printing plate precursor
as claimed in claim 4, wherein the binder polymer comprises an
ammonium group in a side chain.
6. The processing method of a lithographic printing plate precursor
as claimed in claim 1, wherein an oil-desensitizing treatment is
carried out simultaneously with the development processing.
7. The processing method of a lithographic printing plate precursor
as claimed in claim 1, wherein a content of the anionic surfactant
is from 0.3 to 3% by weight of the aqueous solution.
8. The processing method of a lithographic printing plate precursor
as claimed in claim 1, wherein a content of the anionic surfactant
is from 0.5 to 1.5% by weight of the aqueous solution.
9. The processing method of a lithographic printing plate precursor
as claimed in claim 1, wherein the polymerizable compound is an
addition-polymerizable compound having at least one ethylenically
unsaturated double bond.
10. The processing method of a lithographic printing plate
precursor as claimed in claim 1, wherein the amphoteric surfactant
is a compound represented by formula <2> ##STR00385## wherein
R18, R19 and R20 each represents a hydrogen atom or an alkyl group,
provided that all of R18, R19 and R20 are not hydrogen atoms at the
same time.
11. The processing method of a lithographic printing plate
precursor as claimed in claim 1, wherein the aqueous solution has a
pH of from 3 to 7.
Description
[0001] This is a Divisional application of U.S. application Ser.
No. 12/239,035, filed Sep. 26, 2008, which claims priority under 35
U.S.C. .sctn.119 from JP Appln. No. 2007-256706, filed Sep. 28,
2007, the disclosures of all of which are incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a processing method of a
lithographic printing plate precursor, particularly, to a
processing method of a lithographic printing plate precursor which
has an excellent function for preventing printing stain due to
readsorption of a photosensitive layer component (particularly, a
binder) dispersed in a processing solution to a substrate.
BACKGROUND OF THE INVENTION
[0003] In general, a lithographic printing plate is composed of an
oleophilic image area accepting ink and a hydrophilic non-image
area accepting dampening water in the process of printing.
Lithographic printing is a printing method which comprises
rendering the oleophilic image area of the lithographic printing
plate to an ink-receptive area and the hydrophilic non-image area
thereof to a dampening water-receptive area (ink unreceptive area),
thereby making a difference in adherence of ink on the surface of
the lithographic printing plate, and depositing the ink only to the
image area by utilizing the nature of water and printing ink to
repel with each other, and then transferring the ink to a printing
material, for example, paper.
[0004] In order to produce the lithographic printing plate, a
lithographic printing plate precursor (PS plate) comprising a
hydrophilic support having provided thereon an oleophilic
photosensitive resin layer (photosensitive layer or image-recording
layer) has heretofore been broadly used. Ordinarily, the
lithographic printing plate is obtained by conducting plate making
according to a method of exposing the lithographic printing plate
precursor through an original, for example, a lith film, and then
removing the unnecessary portion of the image-recording layer by
dissolving with an alkaline developer or an organic solvent thereby
revealing the hydrophilic surface of support to form the non-image
area while leaving the image-recording layer for forming the image
area.
[0005] Thus, in the hitherto known plate making process of
lithographic printing plate precursor, after exposure, the step of
removing the unnecessary portion of the image-recording layer by
dissolving, for example, with a developer is required. However, in
view of the environment and safety, a processing with a developer
closer to a neutral range and a small amount of waste liquid are
objectives to be achieved. Particularly, since disposal of waste
liquid discharged accompanying the wet treatment has become a great
concern throughout the field of industry in view of the
consideration for global environment in recent years, the demand
for the solution of the above-described problems has been increased
more and more.
[0006] On the other hand, digitalized technique of electronically
processing, accumulating and outputting image information using a
computer has been popularized in recent years, and various new
image outputting systems responding to the digitalized technique
have been put into practical use. Correspondingly, attention has
been drawn to a computer-to-plate (CTP) technique of carrying
digitalized image information on highly converging radiation, for
example, laser light and conducting scanning exposure of a
lithographic printing plate precursor with the light thereby
directly preparing a lithographic printing plate without using a
lith film. Thus, it is one of important technical subjects to
obtain a lithographic printing plate precursor adaptable to the
technique described above.
[0007] As described above, the decrease in alkali concentration of
developer and the simplification of processing step have been
further strongly required from both aspects of the consideration
for global environment and the adaptation for space saving and low
running cost. However, since the development processing ordinarily
comprises three steps of developing with an aqueous alkali solution
having pH of 10 or more, washing of the alkali agent with a
water-washing bath and then treating with a gum solution mainly
comprising a hydrophilic resin as described above, an automatic
developing machine per se requires a large space and problems of
the environment and running cost, for example, disposal of the
development waste liquid, water-washing waste liquid and gum waste
liquid still remain.
[0008] In response, for instance, a developing method using an
alkali solution having pH of 10 to 12.5 and containing a nonionic
surfactant is proposed in JP-A 2002-91016 (the term "JP-A" as used
herein means an "unexamined published Japanese patent application")
(corresponding to US2002/0092436A1). However, since the
photosensitive layer containing an alkali-soluble polymer is used,
there is a problem in that the development can not be performed
with a solution having pH lower than the above-described range.
Also, a lithographic printing plate precursor comprising a
hydrophilic support having provided thereon an image-forming layer
containing hydrophobic thermoplastic polymer particles dispersed in
a hydrophilic binder is described in Japanese Patent 2,938,397
(corresponding to EP0770494A2). The lithographic printing plate
precursor can be exposed imagewise using an infrared laser to
agglomerate the hydrophobic thermoplastic polymer particles by heat
thereby forming an image, and mounted on a cylinder of a printing
machine to carry out on-machine development by supplying dampening
water and/or ink.
[0009] Although the method of forming image by the agglomeration of
fine particles only upon thermal fusion shows good on-machine
development property, it has a problem in that the image strength
(adhesion property to a support) is extremely weak and printing
durability is insufficient.
[0010] As described above, the system including development with an
alkali agent has a problem of supplying a replenisher for
compensating the decrease of pH due to absorption of carbon dioxide
and an apparatus therefor and of increase in the amount of waste
liquid involved and a problem of the running cost of developer as
well as the problem of environment.
[0011] Also, according to the development in an acidic to neutral
range, ordinarily, it is difficult to ensure developing property
and the components of the photosensitive layer removed once in the
non-image area are difficult to be stably dispersed in the
developer. As a result, the components of the photosensitive layer
are precipitated in a developing bath and when running processing
is carried out, a problem may occur in that the precipitates adhere
as development scum on the lithographic printing plate precursor
during the processing to be apt to cause image defect.
SUMMARY OF THE INVENTION
[0012] Therefore, an object of the present invention is to provide
a processing method of a lithographic printing plate precursor
which overcomes the problems of prior art described above. More
specifically, an object of the present invention is to provide a
processing method of a lithographic printing plate precursor which
exhibits an excellent developing property in a development
processing with an aqueous solution having pH of 2 to 10 and
prevents adsorption of an image-recording layer component
(particularly, a binder) removed by development and present in a
processing solution to a substrate and generation of printing
stain.
[0013] As a result of the intensive investigations, the inventors
have found that the above-described object can be achieved by
conducting development processing of a lithographic printing plate
precursor comprising a support on a surface of which a
hydrophilizing treatment and/or an undercoat layer has been
provided and an image-recording layer after image exposure, with an
aqueous solution having pH of 2 to 10 and containing an amphoteric
surfactant and a specific anionic surfactant to complete the
present invention.
[0014] Specifically, the present invention includes the following
items.
(1) A processing method of a lithographic printing plate precursor
comprising exposing imagewise a lithographic printing plate
precursor comprising a support on a surface of which a
hydrophilizing treatment and/or an undercoat layer has been
provided and an image-recording layer to cure an exposed area of
the image-recording layer and then undergoing developing processing
with an aqueous solution having pH of 2 to 10, wherein the aqueous
solution for use in the development processing contains an
amphoteric surfactant and an anionic surfactant selected from an
anionic surfactant having an aliphatic chain and a total number of
carbon atoms included in the aliphatic chain of 6 or more and an
anionic surfactant having an aromatic ring and a total number of
carbon atoms of 12 or more and a content of the anionic surfactant
is from 0.1 to 3.3% by weight of the aqueous solution. (2) The
processing method of a lithographic printing plate precursor as
described in (1) above, wherein the undercoat layer contains an
acid group or a salt of an acid. (3) The processing method of a
lithographic printing plate precursor as described in (2) above,
wherein the acid group is a sulfonic acid group. (4) The processing
method of a lithographic printing plate precursor as described in
any one of (1) to (3) above, wherein the image-recording layer
contains a binder polymer and the binder polymer contains an onium
group. (5) The processing method of a lithographic printing plate
precursor as described in (4) above, wherein the binder polymer
contains an ammonium group in its side chain. (6) The processing
method of a lithographic printing plate precursor as described in
any one of (1) to (5) above, wherein an oil-desensitizing treatment
is carried out simultaneously with the development processing. (7)
A processing solution for development of a lithographic printing
plate precursor comprising an aqueous solution having pH of 2 to 10
and containing an amphoteric surfactant and an anionic surfactant
selected from an anionic surfactant having an aliphatic chain and a
total number of carbon atoms included in the aliphatic chain of 6
or more and an anionic surfactant having an aromatic ring and a
total number of carbon atoms of 12 or more, wherein a content of
the anionic surfactant is from 0.1 to 3.3% by weight of the aqueous
solution.
[0015] According to the present invention, a processing method of a
lithographic printing plate precursor which exhibits an excellent
developing property in a development processing with an aqueous
solution having pH of 2 to 10 and prevents adsorption of an
image-recording layer component (particularly, a binder) removed by
development and present in a processing solution to a substrate and
generation of printing stain can be provided.
[0016] Specifically, in the processing method according to the
invention, the development of image-recording layer progresses not
as layer removal but in the form of dispersion development close to
dissolution development and the image-recording layer is finely
dispersed in the developer during the development. According to the
invention, the component of image-recording layer (particularly, a
binder) thus-dispersed interacts with the surface of substrate to
prevent from adsorption to the surface of substrate (non-image
area). Therefore, the stain at the printing is prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is an illustration for schematically showing a
development processor for use in the processing method of a
lithographic printing plate precursor according to the
invention.
[0018] FIG. 2 is an illustration for schematically showing another
development processor for use in the processing method of a
lithographic printing plate precursor according to the
invention.
[0019] FIG. 3 is an illustration for schematically showing still
another development processor for use in the processing method of a
lithographic printing plate precursor according to the
invention.
DESCRIPTION OF REFERENCE NUMERALS AND SIGNS
[0020] 1: Transport roller pair [0021] 2: Transport roller pair
[0022] 3: Rotating brush roller [0023] 4: Transport roller pair
[0024] 5: Transport roller pair [0025] 6: Rotating brush roller
[0026] 7: Rotating brush roller [0027] 8: Transport roller pair
[0028] 9: Transport roller pair [0029] 10: Backing roller [0030]
11: Transport roller pair [0031] 12: Transport roller pair [0032]
13: Transport roller pair [0033] 106: Developing tank [0034] 108:
Transport roller [0035] 112: Rotating brush
DETAILED DESCRIPTION OF THE INVENTION
[0036] First, the lithographic printing plate precursor for use in
the processing method according to the invention is described
below. The lithographic printing plate precursor used in the
invention has an image-recording layer on a support on a surface of
which a hydrophilizing treatment and/or an undercoat layer has been
provided.
[Image-Recording Layer]
[0037] The image-recording layer of the lithographic printing plate
precursor according to the invention contains a binder polymer, a
polymerizable compound and a polymerization initiator and
preferably further contains a sensitizing dye.
[0038] The components constituting the image-recording layer will
be described in detail below.
<Binder Polymer>
[0039] The binder polymer for use in the image-recording layer
according to the invention is preferably a binder polymer having a
hydrophilic group in view of developing property.
[0040] The hydrophilic group is selected from a monovalent and
divalent hydrophilic groups and preferably includes, for instance,
a hydroxy group, a carboxylate group, a hydroxyethyl group, an
ethyleneoxy group, a hydroxypropyl group, an amino group, an
aminoethyl group, an aminopropyl group, an ammonium group, an amido
group, a carboxymethyl group, an ether group, and a salt formed by
neutralization of an acid group, for example, a carboxylic acid
group, a sulfonic acid group or a phosphoric acid group. An amino
group, an ammonium group, an amido group, a --CH.sub.2CH.sub.2O--
repeating unit or a --CH.sub.2CH.sub.2NH-- repeating unit is
particularly preferable and an amino group or an ammonium group is
most preferable.
[0041] The content of the polymerization component having a
hydrophilic group is preferably from 1 to 70% by mole based on in
the total polymerization component of the binder polymer in view of
developing property. In consideration of the compatibility between
developing property and printing durability, the content is more
preferably from 1 to 50% by mole, particularly preferably from 1 to
30% by mole.
[0042] It is preferred that the binder polymer for use in the
invention does not substantially contain a carboxylic acid group or
a phosphoric acid group in view of developing property and stain
resistance.
[0043] Further, an acid value (acid content per g of polymer,
indicated by the chemical equivalent number) of the binder polymer
is preferably 0.3 meq/g or less, more preferably 0.1 meq/g or
less.
[0044] The binder polymer for use in the invention is preferably
insoluble in water and an aqueous solution having a pH of 10 or
more. The solubility (binder polymer concentration at the
saturation dissolution) of the binder polymer in water or an
aqueous solution having a pH of 10 or more is preferably 1.0% by
weight or less. The temperature for measuring the above-described
solubility is ordinary temperature at the development and it is
25.degree. C. herein.
[0045] The skeleton of the binder polymer for use in the invention
is preferably a polymer compound selected from an acrylic resin, a
vinyl acetal resin, a urethane resin, an amide resin, an epoxy
resin, a methacrylic resin, a styrene resin and an ester resin.
Among them, a vinyl copolymer, for example, an acrylic resin, a
methacrylic resin or a styrene resin and a urethane resin are
particularly preferable.
[0046] It is preferred that the binder polymer for use in the
invention has a crosslinkable group. The term "crosslinkable group"
as used herein means a group having a function capable of
crosslinking the binder polymer in the process of a radical
polymerization reaction which is caused in the photosensitive
layer, when the lithographic printing plate precursor is exposed to
light. The crosslinkable group is not particularly restricted as
long as it has such a function and includes, for example, an
ethylenically unsaturated bonding group, an amino group or an epoxy
group as a functional group capable of conducting an addition
polymerization reaction. Also, a functional group capable of
forming a radical upon irradiation with light may be used and such
a crosslinkable group includes, for example, a thiol group and a
halogen atom. Among them, the ethylenically unsaturated bonding
group is preferable.
[0047] In the binder polymer having a crosslinkable group, for
example, a free radical (a polymerization initiating radical or a
propagating radical in the process of polymerization of the
polymerizable compound) is added to the crosslinkable functional
group to cause an addition-polymerization between polymers directly
or through a polymerization chain of the polymerizable compound, as
a result, crosslinking is formed between polymer molecules to
effect curing. Alternatively, an atom (for example, a hydrogen atom
on the carbon atom adjacent to the functional crosslinkable group)
in the polymer is withdrawn by a free radical to produce a polymer
radical and the polymer radicals combine with each other to form
crosslinking between polymer molecules to effect curing.
[0048] The content of the crosslinkable group (content of
radical-polymerizable unsaturated double bond determined by iodine
titration) in the binder polymer is preferably from 0.1 to 10.0
mmol, more preferably from 1.0 to 7.0 mmol, most preferably from
2.0 to 5.5 mmol, per g of the binder polymer.
[0049] From the standpoint of further improvement in the printing
durability, it is preferred that the crosslinkable group is present
near the hydrophilic group and both the hydrophilic group and the
crosslinkable group may be present in the same polymerization
unit.
[0050] It is preferred that the binder polymer for use in the
invention has a unit of alkyl (meth)acrylate or aralkyl
(meth)acrylate besides the unit having a hydrophilic group, the
unit having a crosslinkable group or the unit having a hydrophilic
group and a crosslinkable group.
[0051] The alkyl group in the alkyl (meth)acrylate is preferably an
alkyl group having from 1 to 5 carbon atoms and more preferably a
methyl group. The aralkyl (meth)acrylate includes, for example,
benzyl (meth)acrylate.
[0052] The binder polymer preferably has a weight average molecular
weight of 5,000 or more, more preferably from 10,000 to 300,000,
and a number average molecular weight of 1,000 or more, more
preferably from 2,000 to 250,000. The polydispersity (weight
average molecular weight/number average molecular weight) is
preferably from 1.1 to 10.
[0053] The binder polymer may be any of a random polymer, a block
polymer, a graft polymer and the like.
[0054] In the image-recording layer according to the invention, a
binder polymer having an amino group and/or ammonium group as the
hydrophilic group (hereinafter, also appropriately referred to as a
"specific binder polymer") is preferably used as described above.
The specific binder polymer will be described in detail below.
[0055] The specific binder polymer may be an appropriate compound
as long as it is a polymer having an amino group and/or ammonium
group in the main chain and/or side chain thereof. Preferably, it
is a polymer having an amino group and/or ammonium group in the
side chain thereof. As the amino group and ammonium group,
respective structures represented by formulae <1> and
<2> described below are preferable. The binder polymer
containing the structure represented by formula <1> or
<2> described below in the side chain thereof may be an
appropriate compound as long as it is a polymer compound containing
at least one group including the structure represented by formula
<1> or <2> in a repeating unit.
##STR00001##
[0056] In formulae <1> and <2>, R1, R2 and R4 to R6
each independently represents a monovalent organic group. The
monovalent organic group is a substituent comprising at least one
atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur,
phosphorus, halogen and silicon. Specifically, it includes
substituents formed from --H, --F, --Cl, --Br, --I, >C<,
.dbd.C<, .ident.C--, --O--, O.dbd., --N<, --N.dbd., .ident.N,
--S--, S.dbd., >S<, .ident.S.ident., --P<, .ident.P<,
>Si<, .dbd.Si<, .ident.Si-- and combinations thereof. More
specifically, a hydrogen atom, an alkyl group, an aryl group, an
alkenyl group, an alkynyl group, a halogen atom, an alkoxy group
and an acyl group are preferably exemplified. R3 and R7 each
represents a single bond or a divalent organic group. The divalent
organic group is a connecting group comprising at least one atom
selected from hydrogen, carbon, oxygen, nitrogen, sulfur,
phosphorus, halogen and silicon. Specifically, it includes
connecting groups formed from --H, --F, --Cl, --Br, --I, >C<,
.dbd.C<, .ident.C--, --O--, O.dbd., --N<, --N.dbd., .ident.N,
--S--, S.dbd., >S<, .ident.S.ident., --P<, .ident.P<,
>Si<, .dbd.Si<, .ident.Si-- and combinations thereof. More
specifically, an alkylene group, an arylene group, a connecting
group containing a hetero atom, for example, an ester bond, an
amido bond or an ether bond, and combinations thereof are
preferably exemplified. Alternatively, appropriate two of R1 to R3
or appropriate two of R4 to R7 may be combined with each other to
form a ring, or appropriate one of R1 to R3 or appropriate one of
R4 to R7 may form a double bond between the nitrogen atom, in this
case R1 or R2 in formula <1> or one of R4 to R6 in formula
<2> is not present. In formula <2>, X.sup.- represents
an anion. In formulae <1> and <2>, * represents a
position connecting to the polymer.
[0057] From the standpoint of developing property in a developer
having pH of 2.0 to 10.0, it is preferred that R1 and R2 in formula
<1> each independently represents a hydrogen atom, an alkyl
group or an aryl group. The total number of carbon atoms included
in R1 and R2 is preferably from 0 to 24, more preferably from 0 to
12. When the total number of carbon atoms included in R1 and R2 is
0, both R1 and R2 represent hydrogen atoms.
[0058] Also, from the standpoint of the developing property in a
developer having pH of 2.0 to 10.0, it is preferred that R4, R5 and
R6 in formula <2> each independently represents a hydrogen
atom, an alkyl group or an aryl group. The total number of carbon
atoms included in R4, R5 and R6 is preferably from 0 to 36, more
preferably from 0 to 18. When the total number of carbon atoms
included in R4, R5 and R6 is 0, R4, R5 and R6 all represent
hydrogen atoms.
[0059] Specific examples of the anion represented by X.sup.-
include a halogen anion, a halogen oxoacid anion (for example,
ClO.sub.4.sup.-, IO.sub.3.sup.- or BrO.sub.3.sup.-), a halogeno
complex anion (for example, BF.sub.4.sup.-, PF.sub.6.sup.- or
AlCl.sub.4.sup.-), a sulfate anion, a nitrate anion, a phosphate
anion, a borate anion, a carboxylate anion, a sulfonate anion, a
phosphonate anion and a metal complex anion (for example,
[Fe(CN).sub.6].sup.-). Among them, from the standpoint of the
developing property in a developer having pH of 2.0 to 10.0, a
halogen anion, a halogeno complex anion, a borate anion, a
carboxylate anion and a sulfonate anion are preferable, and a
halogeno complex anion, a borate anion and a sulfonate anion are
more preferable.
[0060] In order to introduce the amino group or ammonium group into
a polymer, an appropriate method may be used. For instance, a
method wherein a quaternary ammonium group-containing monomer as
shown in Group A below is copolymerized with other polymerizable
compound, a method wherein a tertiary amine-containing monomer as
shown in Group B below is copolymerized with other polymerizable
compound and then the amino group in the copolymer is converted to
tertiary ammonium salt by neutralization with an acid or the amino
group in the copolymer is converted to quaternary ammonium salt
with an alkylating agent, a method wherein a quaternary ammonium
group-containing diol as shown in Group C below is copolymerized
with an isocyanate, carboxylic acid or carboxylic acid derivative,
and a method wherein a tertiary amine-containing diol as shown in
Group D below is copolymerized with an isocyanate, carboxylic acid
or carboxylic acid derivative and then the amino group in the
copolymer is converted to tertiary ammonium salt by neutralization
with an acid or the amino group in the copolymer is converted to
quaternary ammonium salt with an alkylating agent are
exemplified.
##STR00002## ##STR00003## ##STR00004## ##STR00005## ##STR00006##
##STR00007##
[0061] Specific examples of the specific binder polymer including
the structure represented by any one of formulae <1> and
<2> in its repeating unit are set forth below, but the
invention should not be construed as being limited thereto.
[0062] With respect to Polymers PA-1 to PA-68 shown below, the
composition ratio (% by mole) and weight average molecular weight
(Mw) of each polymer are described together with the structure of
the polymer.
[0063] With respect to Polymers PB-1 to PB-50b shown below, the
numeral attached to the compound means a reaction ratio (% by mole)
of each constituting component. Also, "PPG" means polypropylene
glycol and the subsequent numeral means an average molecular
weight. For example, "PPG1000" means polypropylene glycol having an
average molecular weight of 1,000.
TABLE-US-00001 Com- position Molecular Ratio Weight PA-1
##STR00008## 90/10 70000 PA-2 ##STR00009## 90/10 70000 PA-3
##STR00010## 80/20 60000 PA-4 ##STR00011## 80/20 60000 PA-5
##STR00012## 90/5/5 60000 PA-6 ##STR00013## 90/5/5 60000 PA-7
##STR00014## 95/5 70000 PA-8 ##STR00015## 95/5 70000 PA-9
##STR00016## 90/10 70000 PA-10 ##STR00017## 90/10 52000 PA-11
##STR00018## 90/10 58000 PA-12 ##STR00019## 90/10 49000 PA-13
##STR00020## 90/10 50000 PA-14 ##STR00021## 90/10 63000 PA-15
##STR00022## 90/10 80000 PA-16 ##STR00023## 90/10 65000 PA-17
##STR00024## 90/10 60000 PA-18 ##STR00025## 80/20 65000 PA-19
##STR00026## 90/10 90000 PA-20 ##STR00027## 80/20 64000 PA-21
##STR00028## 70/30 77000 PA-22 ##STR00029## 60/35/5 80000 PA-23
##STR00030## 60/35/5 72000 PA-24 ##STR00031## 80/10/10 90000 PA-25
##STR00032## 60/20/20 53000 PA-26 ##STR00033## 80/20 57000 PA-27
##STR00034## 70/30 48000 PA-28 ##STR00035## 60/40 81000 PA-29
##STR00036## 50/50 70000 PA-30 ##STR00037## 50/50 72000 PA-31
##STR00038## 50/50 72000 PA-32 ##STR00039## 50/50 65000 PA-33
##STR00040## 50/50 65000 PA-34 ##STR00041## 60/40 50000 PA-35
##STR00042## 70/30 62000 PA-36 ##STR00043## 30/70 71000 PA-37
##STR00044## 30/70 71000 PA-38 ##STR00045## 60/40 65000 PA-39
##STR00046## 70/30 70000 PA-40 ##STR00047## 70/30 58000 PA-41
##STR00048## 65/35 60000 PA-42 ##STR00049## 60/40 57000 PA-43
##STR00050## 60/40 65000 PA-44 ##STR00051## 50/25/25 49000 PA-45
##STR00052## 50/50 71000 PA-46 ##STR00053## 60/40 65000 PA-47
##STR00054## 70/30 69000 PA-48 ##STR00055## 70/30 60000 PA-49
##STR00056## 70/30 55000 PA-50 ##STR00057## 70/30 50000 PA-51
##STR00058## 70/30 63000 PA-52 ##STR00059## 70/30 58000 PA-53
##STR00060## 70/30 60000 PA-54 ##STR00061## 60/40 58000 PA-55
##STR00062## 70/15/15 60000 PA-56 ##STR00063## 50/50 55000 PA-57
##STR00064## 45/55 60000 PA-58 ##STR00065## 80/20 70000 PA-59
##STR00066## 50/50 60000 PA-60 ##STR00067## 60/40 69000 PA-61
##STR00068## 40/60 80000 PA-62 ##STR00069## 40/60 73000 PA-63
##STR00070## 80/20 50000 PA-64 ##STR00071## 50/50 40000 PA-65
##STR00072## 70/30 50000 PA-66 ##STR00073## 80/20 44000 PA-67
##STR00074## 50/50 55000 PA-68 ##STR00075## 30/70 58000
[0064] In the following tables, "(X)" means "Structure of
Diisocyanate/Dicarboxylic Acid", and "(Y)" means "Structure of
Diol/Diamine".
TABLE-US-00002 (X) PB-1 ##STR00076## PB-2 ##STR00077## PB-3
##STR00078## PB-4 ##STR00079## PB-5 ##STR00080## PB-6 ##STR00081##
PB-7 ##STR00082## PB-8 ##STR00083## PB-9 ##STR00084## PB-10
##STR00085## PB-11 ##STR00086## PB-12 ##STR00087## PB-13
##STR00088## PB-14 ##STR00089## PB-15 ##STR00090## PB-16
##STR00091## PB-17 ##STR00092## PB-18 ##STR00093## PB-19
##STR00094## PB-20 ##STR00095## PB-21 ##STR00096## PB-21b
##STR00097## PB-22 ##STR00098## PB-22b ##STR00099## PB-23
##STR00100## PB-23b ##STR00101## PB-24 ##STR00102## PB-24b
##STR00103## PB-25 ##STR00104## PB-25b ##STR00105## PB-26
##STR00106## PB-26b ##STR00107## PB-27 ##STR00108## PB-27b
##STR00109## PB-28 ##STR00110## PB-28b ##STR00111## PB-29
##STR00112## ##STR00113## PB-30 ##STR00114## ##STR00115## PB-30b
##STR00116## ##STR00117## PB-31 ##STR00118## ##STR00119## PB-31b
##STR00120## ##STR00121## PB-32 ##STR00122## ##STR00123## PB-32b
##STR00124## ##STR00125## PB-33 ##STR00126## ##STR00127## PB-33b
##STR00128## ##STR00129## PB-34 ##STR00130## ##STR00131## PB-34b
##STR00132## ##STR00133## PB-35 ##STR00134## ##STR00135## PB-35b
##STR00136## ##STR00137## PB-36 ##STR00138## ##STR00139## PB-36b
##STR00140## ##STR00141## PB-37 ##STR00142## ##STR00143## PB-37b
##STR00144## ##STR00145## PB-38 ##STR00146## ##STR00147## PB-38b
##STR00148## ##STR00149## PB-39 ##STR00150## ##STR00151## PB-40
##STR00152## ##STR00153## PB-40b ##STR00154## ##STR00155## PB-41
##STR00156## ##STR00157## PB-41b ##STR00158## ##STR00159## PB-42
##STR00160## ##STR00161## PB-42b ##STR00162## ##STR00163## PB-43
##STR00164## ##STR00165## PB-43b ##STR00166## ##STR00167## PB-44
##STR00168## ##STR00169## PB-44b ##STR00170## ##STR00171## PB-45
##STR00172## ##STR00173## PB-45b ##STR00174## ##STR00175## PB-46
##STR00176## ##STR00177## PB-46b ##STR00178## ##STR00179## PB-47
##STR00180## PB-47b ##STR00181## PB-48 ##STR00182## PB-48b
##STR00183## PB-49 ##STR00184## PB-49b ##STR00185## PB-50
##STR00186## PB-50b ##STR00187## (Y) PB-1 ##STR00188## PB-2 PPG1000
20 ##STR00189## PB-3 PPG1000 20 ##STR00190## PB-4 PPG1000 20
##STR00191## PB-5 PPG1000 20 ##STR00192## PB-6 PPG1000 20
##STR00193## PB-7 PPG1000 20 ##STR00194## PB-8 PPG1000 20
##STR00195## PB-9 PPG1000 25 ##STR00196## PB-10 PPG1000 25
##STR00197## PB-11 PPG1000 25 ##STR00198## PB-12 PPG1000 25
##STR00199## PB-13 PPG1000 10 ##STR00200## PB-14 PPG1000 10
##STR00201## PB-15 PPG1000 10 ##STR00202## PB-16 PPG1000 20
##STR00203## PB-17 PPG1000 20 ##STR00204## PB-18 PPG1000 20
##STR00205## PB-19 PPG1000 20 ##STR00206## PB-20 PPG1000 20
##STR00207## PB-21 PPG1000 20 ##STR00208## PB-21b PPG1000 20
##STR00209## PB-22 PPG1000 20 ##STR00210## PB-22b PPG1000 20
##STR00211## PB-23 PPG1000 20 ##STR00212## PB-23b PPG1000 20
##STR00213## PB-24 PPG1000 20 ##STR00214## PB-24b PPG1000 20
##STR00215## PB-25 PPG1000 20 ##STR00216## PB-25b PPG1000 20
##STR00217## PB-26 PPG1000 20 ##STR00218## PB-26b PPG1000 20
##STR00219## PB-27 PPG1000 20 ##STR00220## PB-27b PPG1000 20
##STR00221## PB-28 PPG1000 20 ##STR00222## PB-28b PPG1000 20
##STR00223## PB-29 PEG600 15 ##STR00224## PB-30 PPG1000 10
##STR00225## PB-30b PPG1000 10 ##STR00226## PB-31 PPG1000 10
##STR00227## PB-31b PPG1000 10 ##STR00228## PB-32 PPG1000 10
##STR00229## PB-32b PPG1000 10 ##STR00230## PB-33 PPG1000 10
##STR00231## PB-33b PPG1000 10 ##STR00232##
PB-34 PPG1000 10 ##STR00233## PB-34b PPG1000 10 ##STR00234## PB-35
PPG1000 10 ##STR00235## PB-35b PPG1000 10 ##STR00236## PB-36
PPG1000 10 ##STR00237## PB-36b PPG1000 10 ##STR00238## PB-37
PPG1000 10 ##STR00239## PB-37b PPG1000 10 ##STR00240## PB-38
PPG1000 10 ##STR00241## PB-38b PPG1000 10 ##STR00242## PB-39
PPG1000 10 ##STR00243## PB-40 PEG2000 5 ##STR00244## PB-40b PEG2000
5 ##STR00245## PB-41 PPG700 15 ##STR00246## PB-41b PPG700 15
##STR00247## PB-42 ##STR00248## ##STR00249## PB-42b ##STR00250##
##STR00251## PB-43 ##STR00252## ##STR00253## PB-43b ##STR00254##
##STR00255## PB-44 ##STR00256## ##STR00257## PB-44b ##STR00258##
##STR00259## PB-45 ##STR00260## ##STR00261## PB-45b ##STR00262##
##STR00263## PB-46 ##STR00264## ##STR00265## PB-46b ##STR00266##
##STR00267## PB-47 PPG1000 10 ##STR00268## PB-47b PPG1000 10
##STR00269## PB-48 PEG200 30 ##STR00270## PB-48b PEG200 30
##STR00271## PB-49 PEG200 30 ##STR00272## PB-49b PEG200 30
##STR00273## PB-50 PEG200 25 ##STR00274## PB-50b PEG200 25
##STR00275## (Y) Mw PB-1 60000 PB-2 45000 PB-3 55000 PB-4 50000
PB-5 52000 PB-6 70000 PB-7 78000 PB-8 53000 PB-9 55000 PB-10 56000
PB-11 60000 PB-12 48000 PB-13 55000 PB-14 63000 PB-15 50000 PB-16
52000 PB-17 51000 PB-18 49000 PB-19 53000 PB-20 55000 PB-21 67000
PB-21b 67000 PB-22 79000 PB-22b 79000 PB-23 77000 PB-23b 77000
PB-24 76000 PB-24b 76000 PB-25 80000 PB-25b 80000 PB-26 56000
PB-26b 56000 PB-27 90000 PB-27b 90000 PB-28 78000 PB-28b 78000
PB-29 68000 PB-30 ##STR00276## 59000 PB-30b ##STR00277## 59000
PB-31 ##STR00278## 91000 PB-31b ##STR00279## 91000 PB-32
##STR00280## 84000 PB-32b ##STR00281## 84000 PB-33 ##STR00282##
70000 PB-33b ##STR00283## 70000 PB-34 ##STR00284## 68000 PB-34b
##STR00285## 68000 PB-35 ##STR00286## 75000 PB-35b ##STR00287##
75000 PB-36 ##STR00288## 77000 PB-36b ##STR00289## 77000 PB-37
##STR00290## 80000 PB-37b ##STR00291## 80000 PB-38 ##STR00292##
75000 PB-38b ##STR00293## 75000 PB-39 ##STR00294## 66000 PB-40
##STR00295## 58000 PB-40b ##STR00296## 58000 PB-41 ##STR00297##
70000 PB-41b ##STR00298## 70000 PB-42 ##STR00299## 65000 PB-42b
##STR00300## 65000 PB-43 ##STR00301## 68000 PB-43b ##STR00302##
66000 PB-44 ##STR00303## 70000 PB-44b ##STR00304## 70000 PB-45
##STR00305## 58000 PB-45b ##STR00306## 58000 PB-46 ##STR00307##
60000 PB-46b ##STR00308## 60000 PB-47 ##STR00309## 55000 PB-47b
##STR00310## 55000 PB-48 63000 PB-48b 63000 PB-49 62000 PB-49b
62000 PB-50 ##STR00311## 60000 PB-50b ##STR00312## 60000
[0065] The binder polymers may be used individually or in
combination of two or more thereof. The content of the binder
polymer is preferably from 5 to 75% by weight, more preferably from
10 to 70% by weight, still more preferably from 10 to 60% by
weight, based on the total solid content of the image-recording
layer from the standpoint of good strength of the image area and
good image-forming property.
[0066] The total content of the binder polymer and the
polymerizable compound described below is preferably 80% by weight
or less based on the total solid content of the image-recording
layer. When it exceeds 80% by weight, decrease in sensitivity and
deterioration in developing property may be caused sometimes. It is
more preferably from 35 to 75% by weight.
(Polymerizable Compound)
[0067] The polymerizable compound for use in the image-recording
layer according to the invention is an addition-polymerizable
compound having at least one ethylenically unsaturated double bond,
and it is selected from compounds having at least one, preferably
two or more, terminal ethylenically unsaturated double bonds. Such
compounds are widely known in the art and they can be used in the
invention without any particular limitation. The compound has a
chemical form, for example, a monomer, a prepolymer, specifically,
a dimer, a trimer or an oligomer, or a copolymer thereof, or a
mixture thereof. Examples of the monomer include unsaturated
carboxylic acids (for example, acrylic acid, methacrylic acid,
itaconic acid, crotonic acid, isocrotonic acid or maleic acid) and
esters or amides thereof. Preferably, esters of an unsaturated
carboxylic acid with an aliphatic polyhydric alcohol compound and
amides of an unsaturated carboxylic acid with an aliphatic
polyvalent amine compound are used. An addition reaction product of
an unsaturated carboxylic acid ester or amide having a nucleophilic
substituent, for example, a hydroxy group, an amino group or a
mercapto group, with a monofunctional or polyfunctional isocyanate
or epoxy compound, or a dehydration condensation reaction product
of the unsaturated carboxylic acid ester or amide with a
monofunctional or polyfunctional carboxylic acid is also preferably
used. Moreover, an addition reaction product of an unsaturated
carboxylic acid ester or amide having an electrophilic substituent,
for example, an isocyanate group or an epoxy group with a
monofunctional or polyfunctional alcohol, amine or thiol, or a
substitution reaction product of an unsaturated carboxylic acid
ester or amide having a releasable substituent, for example, a
halogen atom or a tosyloxy group with a monofunctional or
polyfunctional alcohol, amine or thiol is also preferably used. In
addition, compounds in which the unsaturated carboxylic acid
described above is replaced by an unsaturated phosphonic acid,
styrene, vinyl ether or the like can also be used.
[0068] Specific examples of the monomer, which is an ester of an
aliphatic polyhydric alcohol compound with an unsaturated
carboxylic acid, include acrylic acid esters, for example, ethylene
glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol
diacrylate, tetramethylene glycol diacrylate, propylene glycol
diacrylate, neopentyl glycol diacrylate, trimethylolpropane
triacrylate, trimethylolpropane tri(acryloyloxypropyl)ether,
trimethylolethane triacrylate, hexanediol diacrylate,
1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate,
pentaerythritol diacrylate, pentaerythritol triacrylate,
pentaerythritol tetraacrylate, dipentaerythritol diacrylate,
dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol
tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate,
tri(acryloyloxyethyl)isocyanurate, isocyanuric acid ethylene oxide
(EO) modified triacrylate or polyester acrylate oligomer;
methacrylic acid esters, for example, tetramethylene glycol
dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol
dimethacrylate, trimethylolpropane trimethacrylate,
trimethylolethane trimethacrylate, ethylene glycol dimethacrylate,
1,3-butanediol dimethacrylate, hexanediol dimethacrylate,
pentaerythritol dimethacrylate, pentaerythritol trimethacrylate,
pentaerythritol tetramethacrylate, dipentaerythritol
dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol
trimethacrylate, sorbitol tetramethacrylate,
bis[p-(3-methacryloxy-2-hydroxypropoxy)phenyl]dimethylmethane or
bis[p-(methacryloxyethoxy)phenyl]dimethylmethane; itaconic acid
esters, for example, ethylene glycol diitaconate, propylene glycol
diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol
diitaconate, tetramethylene glycol diitaconate, pentaerythritol
diitaconate or sorbitol tetraitaconate; crotonic acid esters, for
example, ethylene glycol dicrotonate, tetramethylene glycol
dicrotonate, pentaerythritol dicrotonate or sorbitol
tetracrotonate; isocrotonic acid esters, for example, ethylene
glycol diisocrotonate, pentaerythritol diisocrotonate or sorbitol
tetraisocrotonate; and maleic acid esters, for example, ethylene
glycol dimaleate, triethylene glycol dimaleate, pentaerythritol
dimaleate and sorbitol tetramaleate.
[0069] Other examples of the ester, which can be preferably used,
include aliphatic alcohol esters described in JP-B-51-47334 (the
term "JP-B" as used herein means an "examined Japanese patent
publication") and JP-A-57-196231, esters having an aromatic
skeleton described in JP-A-59-5240, JP-A-59-5241 and JP-A-2-226149,
and esters containing an amino group described in
JP-A-1-165613.
[0070] The above-described ester monomers can also be used as a
mixture.
[0071] Specific examples of the monomer, which is an amide of an
aliphatic polyvalent amine compound with an unsaturated carboxylic
acid, include methylene bisacrylamide, methylene bismethacrylamide,
1,6-hexamethylene bisacrylamide, 1,6-hexamethylene
bismethacrylamide, diethylenetriamine trisacrylamide, xylylene
bisacrylamide and xylylene bismethacrylamide. Other preferred
examples of the amide monomer include amides having a cyclohexylene
structure described in JP-B-54-21726.
[0072] Urethane type addition-polymerizable compounds produced
using an addition reaction between an isocyanate and a hydroxy
group are also preferably used, and specific examples thereof
include vinylurethane compounds having two or more polymerizable
vinyl groups per molecule obtained by adding a vinyl monomer
containing a hydroxy group represented by formula (A) shown below
to a polyisocyanate compound having two or more isocyanate groups
per molecule, described in JP-B-48-41708.
CH.sub.2.dbd.C(R.sub.4)COOCH.sub.2CH(R.sub.5)OH (A)
wherein R.sub.4 and R.sub.5 each independently represents H or
CH.sub.3.
[0073] Also, urethane acrylates described in JP-A-51-37193,
JP-B-2-32293 and JP-B-2-16765, and urethane compounds having an
ethylene oxide skeleton described in JP-B-58-49860, JP-B-56-17654,
JP-B-62-39417 and JP-B-62-39418 are preferably used. Further, a
photosensitive composition having remarkably excellent photo-speed
can be obtained by using an addition polymerizable compound having
an amino structure or a sulfide structure in its molecule,
described in JP-A-63-277653, JP-A-63-260909 and JP-A-1-105238.
[0074] Other examples include polyfunctional acrylates and
methacrylates, for example, polyester acrylates and epoxy acrylates
obtained by reacting an epoxy resin with (meth)acrylic acid,
described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490.
Specific unsaturated compounds described in JP-B-46-43946,
JP-B-1-40337 and JP-B-1-40336, and vinylphosphonic acid type
compounds described in JP-A-2-25493 can also be exemplified. In
some cases, structure containing a perfluoroalkyl group described
in JP-A-61-22048 can be preferably used. Moreover, photocurable
monomers or oligomers described in Nippon Secchaku Kvokaishi
(Journal of Japan Adhesion Society), Vol. 20, No. 7, pages 300 to
308 (1984) can also be used.
[0075] Details of the method of using the polymerizable compound,
for example, selection of the structure, individual or combination
use or an amount added, can be appropriately determined in
accordance with the characteristic design of the final lithographic
printing plate precursor. For instance, the compound is selected
from the following standpoints.
[0076] In view of the sensitivity, a structure having a large
content of unsaturated group per molecule is preferred and in many
cases, a difunctional or more functional compound is preferred.
Also, in order to increase the strength of the image area, that is,
cured layer, a trifunctional or more functional compound is
preferred. A combination use of compounds different in the
functional number or in the kind of polymerizable group (for
example, an acrylic acid ester, a methacrylic acid ester, a styrene
compound or a vinyl ether compound) is an effective method for
controlling both the sensitivity and the strength.
[0077] The selection and use method of the polymerizable compound
are also important factors for the compatibility and dispersibility
with other components (for example, a binder polymer, a
polymerization initiator or a coloring agent) in the
image-recording layer. For instance, the compatibility may be
improved in some cases by using the compound of low purity or using
two or more kinds of the compounds in combination. A specific
structure may be selected for the purpose of improving an adhesion
property to a support, a protective layer or the like described
hereinafter.
[0078] The polymerizable compound is used preferably in a range of
5 to 80% by weight, more preferably in a range of 25 to 75% by
weight, based on the total solid content of the image-recording
layer. The polymerizable compounds may be used individually or in
combination of two or more thereof. In the method of using the
polymerizable compound, the structure, blend and amount added can
be appropriately selected by taking account of the degree of
polymerization inhibition due to oxygen, resolution, fogging
property, change in refractive index, surface tackiness and the
like.
(Polymerization Initiator)
[0079] The polymerization initiator for use in the image-recording
layer according to the invention is a compound which generates a
radical with light energy or heat energy to initiate or accelerate
polymerization of the polymerizable compound. The polymerization
initiator is appropriately selected to use, for example, from known
radical polymerization initiators and compounds containing a bond
having small bond dissociation energy.
[0080] The polymerization initiators include, for example, organic
halogen compounds, carbonyl compounds, organic peroxides, azo
compounds, azido compounds, metallocene compounds,
hexaarylbiimidazole compounds, organic boron compounds, disulfone
compounds, oxime ester compounds and onium salt compounds.
[0081] The organic halogen compounds described above specifically
include, for example, compounds described in Wakabayashi et al.,
Bull. Chem. Soc. Japan, 42, 2924 (1969), U.S. Pat. No. 3,905,815,
JP-B-46-4605, JP-A-48-36281, JP-A-53-133428, JP-A-55-32070,
JP-A-60-239736, JP-A-61-169835, JP-A-61-169837, JP-A-62-58241,
JP-A-62-212401, JP-A-63-70243, JP-A-63-298339 and M. P. Hutt,
Journal of Heterocyclic Chemistry, 1, No. 3 (1970). Among them,
oxazole compounds and s-triazine compounds each substituted with a
trihalomethyl group are preferable.
[0082] More preferably, s-triazine derivatives in which at least
one of mono-, di- or tri-halogen substituted methyl group is
connected to the s-triazine ring and oxazole derivatives in which
at least one of mono-, di- or tri-halogen substituted methyl group
is connected to the oxazole ring are exemplified. Specific examples
thereof include 2,4,6-tris(monochloromethyl)-s-triazine,
2,4,6-tris(dichloromethyl)-s-triazine,
2,4,6-tris(trichloromethyl)-s-triazine,
2-methyl-4,6-bis(trichloromethyl)-s-triazine,
2-n-propyl-4,6-bis(trichloromethyl)-s-triazine,
2-(.alpha.,.alpha.,.beta.-trichloroethyl)-4,6-bis(trichloromethyl)-s-tria-
zine, 2-(3,4-epoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine,
2-[1-(p-methoxyphenyl)-2,4-butadienyl]-4,6-bis(trichloromethyl)-s-triazin-
e, 2-styryl-4,6-bis(trichloromethyl)-s-triazine,
2-(p-methoxystyryl-4,6-bis(trichloromethyl)-s-triazine,
2-(p-isopropyloxystyryl-4,6-bis(trichloromethyl)-s-triazine,
2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine,
2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine,
2-phenylthio-4,6-bis(trichloromethyl)-s-triazine,
2-benzylthio-4,6-bis(trichloromethyl)-s-triazine,
2,4,6-tris(dibromomethyl)-s-triazine,
2,4,6-tris(tribromomethyl)-s-triazine,
2-methyl-4,6-bis(tribromomethyl)-s-triazine,
2-methoxy-4,6-bis(tribromomethyl)-s-triazine and compounds shown
below.
##STR00313## ##STR00314## ##STR00315##
[0083] The carbonyl compounds described above include, for example,
benzophenone derivatives, e.g., benzophenone, Michler's ketone,
2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone,
2-chlorobenzophenone, 4-bromobenzophenone or 2-carboxybenzophenone,
acetophenone derivatives, e.g., 2,2-dimethoxy-2-phenylacetophenone,
2,2-diethoxyacetophenone, 1-hydroxycyclohexylphenylketone,
.alpha.-hydroxy-2-methylphenylpropane,
1-hydroxy-1-methylethyl-(p-isopropylphenyl)ketone,
1-hydroxy-1-(p-dodecylphenyl)ketone,
2-methyl-(4'-(methylthio)phenyl)-2-morpholino-1-propane or
1,1,1,-trichloromethyl-(p-butylphenyl)ketone, thioxantone
derivatives, e.g., thioxantone, 2-ethylthioxantone,
2-isopropylthioxantone, 2-chlorothioxantone,
2,4-dimethylthioxantone, 2,4-dietylthioxantone or
2,4-diisopropylthioxantone, and benzoic acid ester derivatives,
e.g., ethyl p-dimethylaminobenzoate or ethyl
p-diethylaminobenzoate.
[0084] The azo compounds described above include, for example, azo
compounds described in JP-A-8-108621.
[0085] The organic peroxides described above include, for example,
trimethylcyclohexanone peroxide, acetylacetone peroxide,
1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane,
1,1-bis(tert-butylperoxy)cyclohexane,
2,2-bis(tert-butylperoxy)butane, tert-butylhydroperoxide, cumene
hydroperoxide, diisopropylbenzene hydroperoxide,
2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl
hydroperoxide, tert-butylcumyl peroxide, dicumyl peroxide,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-oxanoyl peroxide,
peroxy succinic acid, benzoyl peroxide, 2,4-dichlorobenzoyl
peroxide, diisopropylperoxy dicarbonate, di-2-ethylhexylperoxy
dicarbonate, di-2-ethoxyethylperoxy dicarbonate,
dimethoxyisopropylperoxy dicarbonate,
di(3-methyl-3-methoxybutyl)peroxy dicarbonate, tert-butylperoxy
acetate, tert-butylperoxy pivalate, tert-butylperoxy neodecanoate,
tert-butylperoxy octanoate, tert-butylperoxy laurate, tersyl
carbonate, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone,
3,3',4,4'-tetra(tert-hexylperoxycarbonyl)benzophenone,
3,3',4,4'-tetra(p-isopropylcumylperoxycarbonyl)benzophenone,
carbonyl di(tert-butylperoxydihydrogen diphthalate) and carbonyl
di(tert-hexylperoxydihydrogen diphthalate).
[0086] The metallocene compounds described above include, for
example, various titanocene compounds described in JP-A-59-152396,
JP-A-61-151197, JP-A-63-41484, JP-A-2-249, JP-A-2-4705 and
JP-A-5-83588, for example, dicyclopentadienyl-Ti-bisphenyl,
dicyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl,
dicyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl,
dicyclopentadienyl-Ti-bis-2,4,6-triafluorophen-1-yl,
dicyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl,
dicyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl,
dimethylcyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl,
dimethylcyclopentadienyl-Ti-bis-2,4,6-triafluorophen-1-yl,
dimethylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl,
dimethylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, or
bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyr-1-yl)phenyl) titanium
and iron-arene complexes described in JP-A-1-304453 and
JP-A-1-152109.
[0087] The hexaarylbiimidazole compounds described above include,
for example, various compounds described in JP-B-6-29285 and U.S.
Pat. Nos. 3,479,185, 4,311,783 and 4,622,286, specifically, for
example, 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole,
2,2'-bis(o-bromophenyl)-4,4',5,5'-tetraphenylbiimidazole,
2,2'-bis(o,p-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole,
2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetra(m-methoxyphenyl)biimidazole,
2,2'-bis(o,o'-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole,
2,2'-bis(o-nitrophenyl)-4,4',5,5'-tetraphenylbiimidazole,
2,2'-bis(o-methylphenyl)-4,4',5,5'-tetraphenylbiimidazole and
2,2'-bis(o-trifluoromethylphenyl)-4,4',5,5'-tetraphenylbiimidazole.
[0088] The organic boron compounds described above include, for
example, organic boric acid salts described in JP-A-62-143044,
JP-A-62-150242, JP-A-9-188685, JP-A-9-188686, JP-A-9-188710,
JP-A-2000-131837, JP-A-2002-107916, Japanese Patent 2764769,
JP-A-2002-116539 and Martin Kunz, Rad Tech '98, Proceeding, Apr.
19-22 (1998), Chicago, organic boron sulfonium complexes or organic
boron oxosulfonium complexes described in JP-A-6-157623,
JP-A-6-175564 and JP-A-6-175561, organic boron iodonium complexes
described in JP-A-6-175554 and JP-A-6-175553, organic boron
phosphonium complexes described in JP-A-9-188710, and organic boron
transition metal coordination complexes described in JP-A-6-348011,
JP-A-7-128785, JP-A-7-140589, JP-A-7-306527 and JP-A-7-292014.
[0089] The disulfone compounds described above include, for
example, compounds described in JP-A-61-166544 and
JP-A-2002-328465.
[0090] The oxime ester compounds described above include, for
example, compounds described in J. C. S. Perkin II, 1653-1660
(1979), J. C. S. Perkin II, 156-162 (1979), Journal of Photopolymer
Science and Technology, 202-232 (1995) and JP-A-2000-66385, and
compounds described in JP-A-2000-80068. Specific examples thereof
include compounds represented by the following structural
formulae:
##STR00316## ##STR00317## ##STR00318## ##STR00319##
[0091] The onium salt compounds described above include onium
salts, for example, diazonium salts described in S. I. Schlesinger,
Photor. Sci. Eng., 18, 387 (1974) and T. S. Bal et al., Polymer,
21, 423 (1980), ammonium salts described in U.S. Pat. No. 4,069,055
and JP-A-4-365049, phosphonium salts described in U.S. Pat. Nos.
4,069,055 and 4,069,056, iodonium salts described in European
Patent 104,143, U.S. Pat. Nos. 339,049 and 410,201, JP-A-2-150848
and JP-A-2-296514, sulfonium salts described in European Patents
370,693, 390,214, 233,567, 297,443 and 297,442, U.S. Pat. Nos.
4,933,377, 161,811, 410,201, 339,049, 4,760,013, 4,734,444 and
2,833,827 and German Patents 2,904,626, 3,604,580 and 3,604,581,
selenonium salts described in J. V. Crivello et al.,
Macromolecules, 10 (6), 1307 (1977) and J. V. Crivello et al., J.
Polymer Sci., Polymer Chem. Ed., 17, 1047 (1979), and arsonium
salts described in C. S. Wen et al., Teh, Proc. Conf. Rad. Curing
ASIA, p. 478, Tokyo, October (1988).
[0092] In the invention, the onium salt functions not as an acid
generator, but as an ionic radical polymerization initiator.
[0093] The onium salts preferably used in the invention include
onium salts represented by the following formulae (RI-I) to
(R-III):
##STR00320##
[0094] In formula (RI-I), Ar.sub.11 represents an aryl group having
20 or less carbon atoms, which may have 1 to 6 substituents.
Preferable examples of the substituent include an alkyl group
having from 1 to 12 carbon atoms, an alkenyl group having from 2 to
12 carbon atoms, an alkynyl group having from 2 to 12 carbon atoms,
an aryl group having from 6 to 12 carbon atoms, an alkoxy group
having from 1 to 12 carbon atoms, an aryloxy group having from 6 to
12 carbon atoms, a halogen atom, an alkylamino group having from 1
to 12 carbon atoms, a dialkylimino group having from 2 to 12 carbon
atoms, an alkylamido group or arylamido having from 2 to 12 carbon
atoms, a carbonyl group, a carboxyl group, a cyano group, a
sulfonyl group, an thioalkyl group having from 1 to 12 carbon atoms
and an thioaryl group having from 6 to 12 carbon atoms.
Z.sub.11.sup.- represents a monovalent anion. Specific examples of
the monovalent anion include a halogen ion, a perchlorate ion, a
hexafluorophosphate ion, a tetrafluoroborate ion, a sulfonate ion,
a sulfinate ion, a thiosulfonate ion and a sulfate ion. Among them,
a perchlorate ion, a hexafluorophosphate ion, a tetrafluoroborate
ion, a sulfonate ion and a sulfinate ion are preferred in view of
stability.
[0095] In the formula (RI-II), Ar.sub.21 and Ar.sub.22 each
independently represents an aryl group having 20 or less carbon
atoms, which may have 1 to 6 substituents. Preferable examples of
the substituent include an alkyl group having from 1 to 12 carbon
atoms, an alkenyl group having from 2 to 12 carbon atoms, an
alkynyl group having from 2 to 12 carbon atoms, an aryl group
having from 6 to 12 carbon atoms, an alkoxy group having from 1 to
12 carbon atoms, an aryloxy group having from 6 to 12 carbon atoms,
a halogen atom, an alkylamino group having from 1 to 12 carbon
atoms, a dialkylimino group having from 2 to 12 carbon atoms, an
alkylamido group or arylamido group having from 2 to 12 carbon
atoms, a carbonyl group, a carboxyl group, a cyano group, a
sulfonyl group, an thioalkyl group having from 1 to 12 carbon atoms
and an thioaryl group having from 6 to 12 carbon atoms.
Z.sub.21.sup.- represents a monovalent anion. Specific examples of
the monovalent anion include a halogen ion, a perchlorate ion, a
hexafluorophosphate ion, a tetrafluoroborate ion, a sulfonate ion,
a sulfinate ion, a thiosulfonate ion, a sulfate ion and a
carboxylate ion. Among them, a perchlorate ion, a
hexafluorophosphate ion, a tetrafluoroborate ion, a sulfonate ion,
a sulfinate ion and a carboxylate ion are preferred in view of
stability and reactivity.
[0096] In the formula (RI-III), R.sub.31, R.sub.32 and R.sub.33
each independently represents an aryl group having 20 or less
carbon atoms, which may have 1 to 6 substituents, an alkyl group,
an alkenyl group or an alkynyl group. Among them, the aryl group is
preferred in view of reactivity and stability. Preferable examples
of the substituent include an alkyl group having from 1 to 12
carbon atoms, an alkenyl group having from 2 to 12 carbon atoms, an
alkynyl group having from 2 to 12 carbon atoms, an aryl group
having from 6 to 12 carbon atoms, an alkoxy group having from 1 to
12 carbon atoms, an aryloxy group having from 6 to 12 carbon atoms,
a halogen atom, an alkylamino group having from 1 to 12 carbon
atoms, a dialkylamino group having from 2 to 12 carbon atoms, an
alkylamido group or arylamido group having from 2 to 12 carbon
atoms, a carbonyl group, a carboxyl group, a cyano group, a
sulfonyl group, an thioalkyl group having from 1 to 12 carbon atoms
and an thioaryl group having from 6 to 12 carbon atoms.
Z.sub.31.sup.- represents a monovalent anion. Specific examples of
the monovalent anion include a halogen ion, a perchlorate ion, a
hexafluorophosphate ion, a tetrafluoroborate ion, a sulfonate ion,
a sulfinate ion, a thiosulfonate ion, a sulfate ion and a
carboxylate ion. Among them, a perchlorate ion, a
hexafluorophosphate ion, a tetrafluoroborate ion, a sulfonate ion,
a sulfinate ion and a carboxylate ion are preferred in view of
stability and reactivity. Carboxylate ions described in
JP-A-2001-343742 are more preferable, and carboxylate ions
described in JP-A-2002-148790 are particularly preferable.
[0097] Specific examples of the onium salt, which are preferably
used, are set forth below.
##STR00321## ##STR00322## ##STR00323## ##STR00324## ##STR00325##
##STR00326##
[0098] The polymerization initiator is not limited to those
described above. In particular, from the standpoint of reactivity
and stability, the triazine type initiators, organic halogen
compounds, metallocene compounds, hexaarylbiimidazole compounds,
organic boron compounds, oxime ester compounds and onium salt
compounds are preferable and the triazine type initiators, organic
halogen compounds, metallocene compounds, hexaarylbiimidazole
compounds and onium salt compounds are more preferable.
[0099] The polymerization initiator can be added preferably in an
amount from 0.1 to 50% by weight, more preferably from 0.5 to 30%
by weight, particularly preferably from 0.8 to 20% by weight, based
on the total solid content of the image-recording layer.
(Other Components)
[0100] To the image-recording layer according to the invention may
further appropriately be added other components suitable for the
use or production method thereof or the like. Other components are
described below.
(Sensitizing Dye)
[0101] The sensitizing dye for use in the image-recording layer
according to the invention is appropriately selected depending on
the use or the like and is not particularly restricted. For
instance, a compound absorbing light of 350 to 450 nm and an
infrared absorbing agent are exemplified.
(1) Compound Absorbing Light of 350 to 450 nm
[0102] As the compound absorbing light of 350 to 450 nm used in the
invention, the sensitizing dye having an absorption maximum in a
wavelength range of 350 to 450 nm is preferable, and examples of
such sensitizing dye include, for example, merocyanine dyes
represented by formula (V) shown below, benzopyranes or coumarins
represented by formula (VI) shown below, aromatic ketones
represented by formula (VII) shown below and anthracenes
represented by formula (VIII) shown below.
##STR00327##
[0103] In formula (V), A represents a sulfur atom or NR.sub.6,
R.sub.6 represents a monovalent non-metallic atomic group, Y
represents a non-metallic atomic group necessary for forming a
basic nucleus of the dye together with adjacent A and the adjacent
carbon atom, and X.sub.1 and X.sub.2 each independently represents
a monovalent non-metallic atomic group or X.sub.1 and X.sub.2 may
be combined with each other to form an acidic nucleus of the
dye.
##STR00328##
[0104] In formula (VI), .dbd.Z represents an oxo group, a thioxo
group, an imino group or an alkylydene group represented by the
partial structural formula (1') described above, X.sub.1 and
X.sub.2 have the same meanings as defined in formula (V)
respectively, and R.sub.7 to R.sub.12 each independently represents
a monovalent non-metallic atomic group.
##STR00329##
[0105] In formula (VII), Ar.sub.3 represents an aromatic group
which may have a substituent or a heteroaromatic group which may
have a substituent, and R.sub.13 represents a monovalent
non-metallic atomic group. R.sub.13 preferably represents an
aromatic group or a heteroaromatic group. Ar.sub.3 and R.sub.13 may
be combined with each other to form a ring.
##STR00330##
[0106] In formula (VIII), X.sub.3, X.sub.4 and R.sub.14 to R.sub.21
each independently represents a monovalent non-metallic atomic
group. Preferably, X.sub.3 and X.sub.4 each independently
represents an electron-donating group having a negative Hammett
substituent constant.
[0107] In formulae (V) to (VIII), preferable examples of the
monovalent non-metallic atomic group represented by any one of
X.sub.1 to X.sub.4 and R.sub.6 to R.sub.21 include a hydrogen atom,
an alkyl group (for example, a methyl group, an ethyl group, a
propyl group, a butyl group, a pentyl group, a hexyl group, a
heptyl group, an octyl group, a nonyl group, a decyl group, an
undecyl group, a dodecyl group, a tridecyl group, a hexadecyl
group, an octadecyl group, an eucosyl group, an isopropyl group, an
isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl
group, a neopentyl group, a 1-methylbutyl group, an isohexyl group,
a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a
cyclopentyl group, a 2-norbornyl group, a chloromethyl group, a
bromomethyl group, a 2-chloroethyl group, a trifluoromethyl group,
a methoxymethyl group, a methoxyethoxyethyl group, an
allyloxymethyl group, a phenoxymethyl group, a methylthiomethyl
group, a tolylthiomethyl group, an ethylaminoethyl group, a
diethylaminopropyl group, a morpholinopropyl group, an
acetyloxymethyl group, a benzoyloxymethyl group, an
N-cyclohexylcarbamoyloxyethyl group, an N-phenylcarbamoyloxyethyl
group, an acetylaminoethyl group, an N-methylbenzoylaminopropyl
group, a 2-oxoethyl group, a 2-oxopropyl group, a carboxypropyl
group, a methoxycarbonylethyl group, an allyloxycarbonylbutyl
group, a chlorophenoxycarbonylmethyl group, a carbamoylmethyl
group, an N-methylcarbamoylethyl group, an
N,N-dipropylcarbamoylmethyl group, an
N-(methoxyphenyl)carbamoylethyl group, an
N-methyl-N-(sulfophenyl)carbamoylmethyl group, a sulfobutyl group,
a sulfonatobutyl group, a sulfamoylbutyl group, an
N-ethylsulfamoylmethyl group, an N,N-dipropyl-sulfamoylpropyl
group, an N-tolylsulfamoylpropyl group, an
N-methyl-N-(phosphonophenyl)sulfamoyloctyl group, a phosphonobutyl
group, a phosphonatohexyl group, a diethylphosphonobutyl group, a
diphenylphosphonopropyl group, a methylphosphonobutyl group, a
methylphosphonatobutyl group, a tolylphosphonohexyl group, a
tolylphosphonatohexyl group, a phosphonooxypropyl group, a
phosphonatooxybutyl group, a benzyl group, a phenethyl group, an
.alpha.-methylbenzyl group, a 1-methyl-1-phenylethyl group, a
p-methylbenzyl group, a cinnamyl group, an allyl group, a
1-propenylmethyl group, a 2-butenyl group, a 2-methylallyl group, a
2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group
or a 3-butynyl group), an aryl group (for example, a phenyl group,
a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a
mesityl group, a cumenyl group, a chlorophenyl group, a bromophenyl
group, a chloromethylphenyl group, a hydroxyphenyl group, a
methoxyphenyl group, an ethoxyphenyl group, a phenoxyphenyl group,
an acetoxyphenyl group, a benzoyloxyphenyl group, a
methylthiophenyl group, a phenylthiophenyl group, a
methylaminophenyl group, a dimethylaminophenyl group, an
acetylaminophenyl group, a carboxyphenyl group, a
methoxycarbonylphenyl group, an ethoxycarbonylphenyl group, a
phenoxycarbonylphenyl group, an N-phenylcarbamoylphenyl group, a
nitrophenyl group, a cyanophenyl group, a sulfophenyl group, a
sulfonatophenyl group, a phosphonophenyl group or a
phosphonatophenyl group), a heteroaryl group (for example, a group
derived from a heteroaryl ring, for example, thiophene, thiathrene,
furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine,
pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine,
pyridazine, indolizine, isoindolizine, indole, indazole, purine,
quinolizine, isoquinoline, phthalazine, naphthylidine, quinazoline,
cinnoline, pteridine, carbazole, carboline, phenanthrine, acridine,
perimidine, phenanthroline, phthalazine, phenarsazine, phenoxazine,
furazane or phenoxazine), an alkenyl group (for example, a vinyl
group, a 1-propenyl group, a 1-butenyl group, a cinnamyl group or a
2-chloro-1-ethenyl group), an alkynyl group (for example, an
ethynyl group, a 1-propynyl group, a 1-butynyl group or a
trimethylsilylethynyl group), a halogen atom (for example, --F,
--Br, --Cl or --I), a hydroxy group, an alkoxy group, an aryloxy
group, a mercapto group, an alkylthio group, an arylthio group, an
alkyldithio group, an aryldithio group, an amino group, an
N-alkylamino group, an N,N-dialkylamino group, an N-arylamino
group, an N,N-diarylamino group, an N-alkyl-N-arylamino group, an
acyloxy group, a carbamoyloxy group, an N-alkylcarbamoyloxy group,
an N-arylcarbamoyloxy group, an N,N-dialkylcarbamoyloxy group, an
N,N-diarylcarbamoyloxy group, an N-alkyl-N-arylcarbamoyloxy group,
an alkylsulfoxy group, an arylsulfoxy group, an acylthio group, an
acylamino group, an N-alkylacylamino group, an N-arylacylamino
group, a ureido group, an N'-alkylureido group, an
N',N'-dialkylureido group, an N'-arylureido group, an
N',N'-diarylureido group, an N'-alkyl-N'-arylureido group, an
N-alkylureido group, an N-arylureido group, an
N'-alkyl-N-alkylureido group, an N'-alkyl-N-arylureido group, an
N',N'-dialkyl-N-alkylureido group, an N',N'-dialkyl-N-arylureido
group, an N'-aryl-N-alkylureido group, an N'-aryl-N-arylureido
group, an N',N'-diaryl-N-alkylureido group, an
N',N'-diaryl-N-aryl-ureido group, an N'-alkyl-N'-aryl-N-alkylureido
group, an N'-alkyl-N'-aryl-N-arylureido group, an
alkoxycarbonylamino group, an aryloxycarbonylamino group, an
N-alkyl-N-alkoxycarbonylamino group, an
N-alkyl-N-aryloxycarbonylamino group, an
N-aryl-N-alkoxycarbonylamino group, an
N-aryl-N-aryloxycarbonylamino group, a formyl group, an acyl group,
a carboxyl group, an alkoxycarbonyl group, an aryloxycarbonyl
group, a carbamoyl group, an N-alkylcarbamoyl group, an
N,N-dialkylcarbamoyl group, an N-arylcarbamoyl group, an
N,N-diarylcarbamoyl group, an N-alkyl-N-arylcarbamoyl group, an
alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group,
an arylsulfonyl group, a sulfo group (--SO.sub.3H) and its
conjugated base group (hereinafter referred to as a "sulfonato
group"), an alkoxysulfonyl group, an aryloxysulfonyl group, a
sulfinamoyl group, an N-alkylsulfinamoyl group, an
N,N-dialkylsulfinamoyl group, an N-arylsulfinamoyl group, an
N,N-diarylsulfinamoyl group, an N-alkyl-N-arylsulfinamoyl group, a
sulfamoyl group, an N-alkylsulfamoyl group, an N,N-dialkylsulfamoyl
group, an N-arylsulfamoyl group, an N,N-diarylsulfamoyl group, an
N-alkyl-N-arylsulfamoyl group, a phosphono group
(--PO.sub.3H.sub.2) and its conjugated base group (hereinafter
referred to as a "phosphonato group"), a dialkylphosphono group
(--PO.sub.3(alkyl).sub.2), a diarylphosphono group
(--PO.sub.3(aryl).sub.2), an alkylarylphosphono group
(--PO.sub.3(alkyl)(aryl)), a monoalkylphosphono group
(--PO.sub.3H(alkyl)) and its conjugated base group (hereinafter
referred to as an "alkylphosphonato group"), a monoarylphosphono
group (--PO.sub.3H(aryl)) and its conjugated base group
(hereinafter referred to as an "arylphosphonato group"), a
phosphonooxy group (--OPO.sub.3H.sub.2) and its conjugated base
group (hereinafter referred to as a "phosphonatooxy group"), a
dialkylphosphonooxy group (--OPO.sub.3(alkyl).sub.2), a
diarylphosphonooxy group (--OPO.sub.3(aryl).sub.2), an
alkylarylphosphonooxy group (--OPO.sub.3(alkyl)(aryl)), a
monoalkylphosphonooxy group (--OPO.sub.3H(alkyl)) and its
conjugated base group (hereinafter referred to as an
"alkylphosphonatooxy group"), a monoarylphosphonooxy group
(--OPO.sub.3H(aryl)) and its conjugated base group (hereinafter
referred to as an "arylphosphonatooxy group"), a cyano group and a
nitro group. Among the above-described groups, a hydrogen atom, an
alkyl group, an aryl group, a halogen atom, an alkoxy group and an
acyl group are particularly preferred.
[0108] The basic nucleus of the dye formed by Y together with the
adjacent A and the adjacent carbon atom in formula (V) includes,
for example, a 5-membered, 6-membered or 7-membered,
nitrogen-containing or sulfur-containing heterocyclic ring, and is
preferably a 5-membered or 6-membered heterocyclic ring.
[0109] As the nitrogen-containing heterocyclic ring, those which
are known to constitute basic nuclei in merocyanine dyes described
in L. G. Brooker et al, J. Am. Chem. Soc., Vol. 73, pp. 5326 to
5358 (1951) and references cited therein can be preferably used.
Specific examples thereof include thiazoles (for example, thiazole,
4-methylthiazole, 4-phenylthiazole, 5-methylthiazole,
5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole,
4,5-di(p-methoxyphenyl)thiazole or 4-(2-thienyl)thiazole);
benzothiazoles (for example, benzothiazole, 4-chlorobenzothiazole,
5-chlorobenzothiazole, 6-chlorobenzothiazole,
7-chlorobenzothiazole, 4-methylbenzothiazole,
5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole,
4-phenylbenzothiazole, 5-phenylbenzothiazole,
4-methoxybenzothiazole, 5-methoxybenzothiazole,
6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole,
4-ethoxybenzothiazole, 5-ethoxybenzothiazole,
tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole,
5,6-dioxymethylenebenzothiazole, 5-hydroxybenzothiazole,
6-hydroxybenzothiazole, 6-dimethylaminobenzothiazole or
5-ethoxycarbonylbenzothiazole); naphthothiazoles (for example,
naphtho[1,2]thiazole, naphtho[2,1]thiazole,
5-methoxynaphtho[2,1]thiazole, 5-ethoxynaphtho[2,1]thiazole,
8-methoxynaphtho[1,2]thiazole or 7-methoxynaphtho[1,2]thiazole);
thianaphtheno-7',6',4,5-thiazoles (for example,
4'-methoxythianaphtheno-7',6',4,5-thiazole); oxazoles (for example,
4-methyloxazole, 5-methyloxazole, 4-phenyloxazole,
4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole or
5-phenyloxazole); benzoxazoles (for example, benzoxazole,
5-chlorobenzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole,
6-methylbenzoxazole, 5,6-dimethylbenzoxazole,
4,6-dimethylbenzoxazole, 6-methoxybenzoxazole,
5-methoxybenzoxazole, 4-ethoxybenzoxazole, 5-chlorobenzoxazole,
6-methoxybenzoxazole, 5-hydroxybenzoxazole or
6-hydroxybenzoxazole); naphthoxazoles (for example,
naphth[1,2]oxazole or naphth[2,1]oxazole); selenazoles (for
example, 4-methylselenazole or 4-phenylselenazole);
benzoselenazoles (for example, benzoselenazole,
5-chlorobenzoselenazole, 5-methoxybenzoselenazole,
5-hydroxybenzoselenazole or tetrahydrobenzoselenazole);
naphthoselenazoles (for example, naphtho[1,2]selenazole or
naphtho[2,1]selenazole); thiazolines (for example, thiazoline or
4-methylthiazoline); quinolines (for example, quinoline,
3-methylquinoline, 5-methylquinoline, 7-methylquinoline,
8-methylquinoline, 6-chloroquinoline, 8-chloroquinoline,
6-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline or
8-hydroxyquinoline); isoquinolines (for example, isoquinoline or
3,4-dihydroisoquinoline); benzimidazoles (for example,
1,3-diethylbenzimidazole or 1-ethyl-3-phenylbenzimidazole);
3,3-dialkylindolenines (for example, 3,3-dimethylindolenine,
3,3,5-trimethylindolenine or 3,3,7-trimethylindolenine); and
pyridines (for example, pyridine or 5-methylpyridine).
[0110] Examples of the sulfur-containing heterocyclic ring include
dithiol partial structures in dyes described in JP-A-3-296759.
[0111] Specific examples thereof include benzodithiols (for
example, benzodithiol, 5-tert-butylbenzodithiol or
5-methylbenzodithiol); naphthodithiols (for example,
naphtho[1,2]dithiol or naphtho[2,1]dithiol); and dithiols (for
example, 4,5-dimethyldithiol, 4-phenyldithiol,
4-methoxycarbonyldithiol, 4,5-dimethoxycarbonyldithiol,
4,5-ditrifluoromethyldithiol, 4,5-dicyanodithiol,
4-methoxycarbonylmethyldithiol or 4-carboxymethyldithiol).
[0112] In the description with respect to the heterocyclic ring
above, for convenience and by convention, the names of heterocyclic
mother skeletons are used. In the case of constituting the basic
nucleus partial structure in the sensitizing dye, the heterocyclic
ring is introduced in the form of a substituent of alkylydene type
where a degree of unsaturation is decreased one step. For example,
a benzothiazole skeleton is introduced as a
3-substituted-2(3H)-benzothiazolilydene group.
[0113] Of the sensitizing dyes having an absorption maximum in a
wavelength range of 350 to 450 nm, dyes represented by formula (IX)
shown below are more preferable in view of high sensitivity.
##STR00331##
[0114] In formula (IX), A represents an aromatic cyclic group which
may have a substituent or a heterocyclic group which may have a
substituent, X represents an oxygen atom, a sulfur atom or
.dbd.N(R.sub.3), and R.sub.1, R.sub.2 and R.sub.3 each
independently represents a monovalent non-metallic atomic group, or
A and R.sub.1 or R.sub.2 and R.sub.3 may be combined with each
other to form an aliphatic or aromatic ring.
[0115] The formula (IX) will be described in more detail below.
R.sub.1, R.sub.2 and R.sub.3 each independently represents a
monovalent non-metallic atomic group, preferably a substituted or
unsubstituted alkyl group, a substituted or unsubstituted alkenyl
group, a substituted or unsubstituted aryl group, a substituted or
unsubstituted aromatic heterocyclic residue, a substituted or
unsubstituted alkoxy group, a substituted or unsubstituted
alkylthio group, a hydroxy group or a halogen atom.
[0116] Preferable examples of R.sub.1, R.sub.2 and R.sub.3 will be
specifically described below. Preferable examples of the alkyl
group include a straight chain, branched or cyclic alkyl group
having from 1 to 20 carbon atoms. Specific examples thereof include
a methyl group, an ethyl group, a propyl group, a butyl group, a
pentyl group, a hexyl group, a heptyl group, an octyl group, a
nonyl group, a decyl group, an undecyl group, a dodecyl group, a
tridecyl group, a hexadecyl group, an octadecyl group, an eucosyl
group, an isopropyl group, an isobutyl group, a sec-butyl group, a
tert-butyl group, an isopentyl group, a neopentyl group, a
1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a
2-methylhexyl group, a cyclohexyl group, a cyclopentyl group and a
2-norbornyl group. Among them, a straight chain alkyl group having
from 1 to 12 carbon atoms, a branched alkyl group having from 3 to
12 carbon atoms and a cyclic alkyl group having from 5 to 10 carbon
atoms are more preferable.
[0117] As the substituent for the substituted alkyl group, a
monovalent non-metallic atomic group exclusive of a hydrogen atom
is used. Preferable examples thereof include a halogen atom (for
example, --F, --Br, --Cl or --I), a hydroxy group, an alkoxy group,
an aryloxy group, a mercapto group, an alkylthio group, an arylthio
group, an alkyldithio group, an aryldithio group, an amino group,
an N-alkylamino group, an N,N-dialkylamino group, an N-arylamino
group, an N,N-diarylamino group, an N-alkyl-N-arylamino group, an
acyloxy group, a carbamoyloxy group, an N-alkylcarbamoyloxy group,
an N-arylcarbamoyloxy group, an N,N-dialkylcarbamoyloxy group, an
N,N-diarylcarbamoyloxy group, an N-alkyl-N-arylcarbamoyloxy group,
an alkylsulfoxy group, an arylsulfoxy group, an acylthio group, an
acylamino group, an N-alkylacylamino group, an N-arylacylamino
group, a ureido group, an N'-alkylureido group, an
N',N'-dialkylureido group, an N'-arylureido group, an
N',N'-diarylureido group, an N'-alkyl-N'-arylureido group, an
N-alkylureido group, an N-arylureido group, an
N'-alkyl-N-alkylureido group, an N'-alkyl-N-arylureido group, an
N',N'-dialkyl-N-alkylureido group, an N',N'-dialkyl-N-arylureido
group, an N'-aryl-N-alkylureido group, an N'-aryl-N-arylureido
group, an N',N'-diaryl-N-alkylureido group, an
N',N'-diaryl-N-arylureido group, an N'-alkyl-N'-aryl-N-alkylureido
group, an N'-alkyl-N'-aryl-N-arylureido group, an
alkoxycarbonylamino group, an aryloxycarbonylamino group, an
N-alkyl-N-alkoxycarbonylamino group, an
N-alkyl-N-aryloxycarbonylamino group, an
N-aryl-N-alkoxycarbonylamino group, an
N-aryl-N-aryloxycarbonylamino group, an acyl group, a carboxyl
group, an alkoxycarbonyl group, an aryloxycarbonyl group, a
carbamoyl group, an N-alkylcarbamoyl group, an N,N-dialkylcarbamoyl
group, an N-arylcarbamoyl group, an N,N-diarylcarbamoyl group, an
N-alkyl-N-arylcarbamoyl group, an alkylsulfinyl group, an
arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group,
a sulfo group (--SO.sub.3H) and its conjugated base group
(hereinafter referred to as a "sulfonato group"), an alkoxysulfonyl
group, an aryloxysulfonyl group, a sulfinamoyl group, an
N-alkylsulfinamoyl group, an N,N-dialkylsulfinamoyl group, an
N-aryl-sulfinamoyl group, an N,N-diarylsulfinamoyl group, an
N-alkyl-N-arylsulfinamoyl group, a sulfamoyl group, an
N-alkylsulfamoyl group, an N,N-dialkylsulfamoyl group, an
N-arylsulfamoyl group, an N,N-diarylsulfamoyl group, an
N-alkyl-N-arylsulfamoyl group, a phosphono group
(--PO.sub.3H.sub.2) and its conjugated base group (hereinafter
referred to as a "phosphonato group"), a dialkylphosphono group
(--PO.sub.3(alkyl).sub.2), a diarylphosphono group
(--PO.sub.3(aryl).sub.2), an alkylarylphosphono group
(--PO.sub.3(alkyl)(aryl)), a monoalkylphosphono group
(--PO.sub.3H(alkyl)) and its conjugated base group (hereinafter
referred to as an "alkylphosphonato group"), a monoarylphosphono
group (--PO.sub.3H(aryl)) and its conjugated base group
(hereinafter referred to as an "arylphosphonato group"), a
phosphonooxy group (--OPO.sub.3H.sub.2) and its conjugated base
group (hereinafter referred to as a "phosphonatooxy group"), a
dialkylphosphonooxy group (--OPO.sub.3(alkyl).sub.2), a
diarylphosphonooxy group (--OPO.sub.3(aryl).sub.2), an
alkylarylphosphonooxy group (--OPO.sub.3(alkyl)(aryl)), a
monoalkylphosphonooxy group (--OPO.sub.3H(alkyl)) and its
conjugated base group (hereinafter referred to as an
"alkylphosphonatooxy group"), a monoarylphosphonooxy group
(--OPO.sub.3H(aryl)) and its conjugated base group (hereinafter
referred to as an "arylphosphonatooxy group"), a cyano group, a
nitro group, an aryl group, a heteroaryl group, an alkenyl group
and an alkynyl group.
[0118] In the substituents, specific examples of the alkyl group
include those described for the alkyl group above. Specific
examples of the aryl group include a phenyl group, a biphenyl
group, a naphthyl group, a tolyl group, a xylyl group, a mesityl
group, a cumenyl group, a chlorophenyl group, a bromophenyl group,
a chloromethylphenyl group, a hydroxy-phenyl group, a methoxyphenyl
group, an ethoxyphenyl group, a phenoxyphenyl group, an
acetoxyphenyl group, a benzoyloxyphenyl group, a methylthiophenyl
group, a phenylthiophenyl group, a methylaminophenyl group, a
dimethylaminophenyl group, an acetylaminophenyl group, a
carboxyphenyl group, a methoxycarbonylphenyl group, an
ethoxycarbonylphenyl group, a phenoxycarbonylphenyl group, an
N-phenylcarbamoylphenyl group, a nitrophenyl group, a cyanophenyl
group, a sulfophenyl group, a sulfonatophenyl group, a
phosphonophenyl group and a phosphonatophenyl group.
[0119] Examples of the heteroaryl group include a monocyclic or
polycyclic aromatic cyclic group containing at least one of a
nitrogen atom, an oxygen atom and a sulfur atom. Examples of
especially preferable heteroaryl group include a group derived from
a heteroaryl ring, for example, thiophene, thiathrene, furan,
pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole,
pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine,
indolizine, isoindolizine, indole, indazole, purine, quinolizine,
isoquinoline, phthalazine, naphthylidine, quinazoline, cinnoline,
pteridine, carbazole, carboline, phenanthrene, acridine,
perimidine, phenanthroline, phthalazine, phenarsazine, phenoxazine,
furazane or phenoxazine. These groups may be benzo-fused or may
have a substituent.
[0120] Also, examples of the alkenyl group include a vinyl group, a
1-propenyl group, a 1-butenyl group, a cinnamyl group and a
2-chloro-1-ethenyl group. Examples of the alkynyl group include an
ethynyl group, a 1-propynyl group, a 1-butynyl group and a
trimethylsilylethynyl group. Examples of G.sub.1 in the acyl group
(G.sub.1CO--) include a hydrogen atom and the above-described alkyl
group and aryl group. Of the substituents, a halogen atom (for
example, --F, --Br, --Cl or --I), an alkoxy group, an aryloxy
group, an alkylthio group, an arylthio group, an N-alkylamino
group, an N,N-dialkylamino group, an acyloxy group, an
N-alkylcarbamoyloxy group, an N-arylcarbamoyloxy group, an
acylamino group, an acyl group, a carboxyl group, an alkoxycarbonyl
group, an aryloxycarbonyl group, a carbamoyl group, an
N-alkylcarbamoyl group, an N,N-dialkylcarbamoyl group, an
N-arylcarbamoyl group, an N-alkyl-N-arylcarbamoyl group, a sulfo
group, a sulfonato group, a sulfamoyl group, an N-alkylsulfamoyl
group, an N,N-dialkylsulfamoyl group, an N-arylsulfamoyl group, an
N-alkyl-N-arylsulfamoyl group, a phosphono group, a phosphonato
group, a dialkylphosphono group, a diarylphosphono group, a
monoalkylphosphono group, an alkylphosphonato group, a
monoarylphosphono group, an arylphosphonato group, a phosphonooxy
group, a phosphonatooxy group, an aryl group and an alkenyl group
are more preferable.
[0121] On the other hand, as an alkylene group in the substituted
alkyl group, a divalent organic residue resulting from elimination
of any one of hydrogen atoms on the above-described alkyl group
having from 1 to 20 carbon atoms can be enumerated. Examples of
preferable alkylene group include a straight chain alkylene group
having from 1 to 12 carbon atoms, a branched alkylene group having
from 3 to 12 carbon atoms and a cyclic alkylene group having from 5
to 10 carbon atoms.
[0122] Specific examples of the preferable substituted alkyl group
represented by any one of R.sub.1, R.sub.2 and R.sub.3, which is
obtained by combining the above-described substituent with the
alkylene group, include a chloromethyl group, a bromomethyl group,
a 2-chloroethyl group, a trifluoromethyl group, a methoxymethyl
group, a methoxyethoxyethyl group, an allyloxymethyl group, a
phenoxymethyl group, a methylthiomethyl group, a tolylthiomethyl
group, an ethylaminoethyl group, a diethylaminopropyl group, a
morpholinopropyl group, an acetyloxymethyl group, a
benzoyloxymethyl group, an N-cyclohexylcarbamoyloxyethyl group, an
N-phenylcarbamoyloxyethyl group, an acetylaminoethyl group, an
N-methylbenzoylaminopropyl group, a 2-oxoethyl group, a 2-oxopropyl
group, a carboxypropyl group, a methoxycarbonylethyl group, an
allyloxycarbonylbutyl group, a chlorophenoxycarbonylmethyl group, a
carbamoylmethyl group, an N-methylcarbamoylethyl group, an
N,N-dipropylcarbamoylmethyl group, an
N-(methoxyphenyl)carbamoylethyl group, an
N-methyl-N-(sulfophenyl)carbamoylmethyl group, a sulfobutyl group,
a sulfonatobutyl group, a sulfamoylbutyl group, an
N-ethylsulfamoylmethyl group, an N,N-dipropyl-sulfamoylpropyl
group, an N-tolylsulfamoylpropyl group, an
N-methyl-N-(phosphonophenyl)sulfamoyloctyl group, a phosphonobutyl
group, a phosphonatohexyl group, a diethylphosphonobutyl group, a
diphenylphosphonopropyl group, a methylphosphonobutyl group, a
methylphosphonatobutyl group, a tolylphosphonohexyl group, a
tolylphosphonatohexyl group, a phosphonooxypropyl group, a
phosphonatooxybutyl group, a benzyl group, a phenethyl group, an
.alpha.-methylbenzyl group, a 1-methyl-1-phenylethyl group, a
p-methylbenzyl group, a cinnamyl group, an allyl group, a
1-propenylmethyl group, a 2-butenyl group, a 2-methylallyl group, a
2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group
and a 3-butynyl group.
[0123] Preferable examples of the aryl group represented by any one
of R.sub.1, R.sub.2 and R.sub.3 include a fused ring formed from
one to three benzene rings and a fused ring formed from a benzene
ring and a 5-membered unsaturated ring. Specific examples thereof
include a phenyl group, a naphthyl group, an anthryl group, a
phenanthryl group, an indenyl group, an acenaphthenyl group and a
fluorenyl group. Among them, a phenyl group and a naphthyl group
are more preferable.
[0124] Specific examples of the preferable substituted aryl group
represented by any one of R.sub.1, R.sub.2 and R.sub.3 include aryl
groups having a monovalent non-metallic atomic group exclusive of a
hydrogen atom as a substituent on the ring-forming carbon atom of
the above-described aryl group. Preferable examples of the
substituent include the above-described alkyl groups and
substituted alkyl groups, and the substituents described for the
above-described substituted alkyl group. Specific examples of the
preferable substituted aryl group include a biphenyl group, a tolyl
group, a xylyl group, a mesityl group, a cumenyl group, a
chlorophenyl group, a bromophenyl group, a fluorophenyl group, a
chloromethylphenyl group, a trifluoromethylphenyl group, a
hydroxyphenyl group, a methoxyphenyl group, a methoxyethoxyphenyl
group, an allyloxyphenyl group, a phenoxyphenyl group, a
methylthiophenyl group, a tolylthiophenyl group, an
ethylaminophenyl group, a diethylaminophenyl group, a
morpholinophenyl group, an acetyloxyphenyl group, a
benzoyloxyphenyl group, an N-cyclohexylcarbamoyloxyphenyl group, an
N-phenylcarbamo-yloxyphenyl group, an acetylaminophenyl group, an
N-methylbenzoylaminophenyl group, a carboxyphenyl group, a
methoxycarbonylphenyl group, an allyloxycarbonylphenyl group, a
chlorophenoxycarbonylphenyl group, a carbamoylphenyl group, an
N-methylcarbamoylphenyl group, an N,N-dipropylcarbamoylphenyl
group, an N-(methoxyphenyl)carbamoylphenyl group, an
N-methyl-N-(sulfophenyl)carbamoylphenyl group, a sulfophenyl group,
a sulfonatophenyl group, a sulfamoylphenyl group, an
N-ethylsulfamoylphenyl group, an N,N-dipropylsulfamoylphenyl group,
an N-tolylsulfamoylphenyl group, an
N-methyl-N-(phosphonophenyl)sulfamoylphenyl group, a
phosphonophenyl group, a phosphonatophenyl group, a
diethylphosphonophenyl group, a diphenylphosphonophenyl group, a
methylphosphonophenyl group, a methylphosphonatophenyl group, a
tolylphosphonophenyl group, a tolylphosphonatophenyl group, an
allylphenyl group, a 1-propenylmethylphenyl group, a
2-butenylphenyl group, a 2-methylallylphenyl group, a
2-methylpropenylphenyl group, a 2-propynylphenyl group, a
2-butynylphenyl group and a 3-butynylphenyl group.
[0125] Examples of the preferable substituted or unsubstituted
alkenyl group and the preferable substituted or unsubstituted
aromatic heterocyclic residue represented by any one of R.sub.1,
R.sub.2 and R.sub.3 include those described with respect to the
alkenyl group and heteroaryl group above, respectively.
[0126] Next, A in formula (IX) will be described below. A
represents an aromatic cyclic group which may have a substituent or
heterocyclic group which may have a substituent. Specific examples
of the aromatic cyclic group which may have a substituent and
heterocyclic group which may have a substituent include the aryl
groups and the aromatic heterocyclic residues described for any one
of R.sub.1, R.sub.2 and R.sub.3 in formula (IX).
[0127] The sensitizing dye represented by formula (IX) is obtained
by a condensation reaction of the above-described acidic nucleus or
an active methyl group-containing acidic nucleus with a substituted
or unsubstituted, aromatic ring or hetero ring, and in particular,
can be synthesized with reference to the description of
JP-B-59-28329.
[0128] Preferable specific examples (D1) to (D75) of the compound
represented by formula (IX) are set forth below. Further, when
isomers with respect to a double bond connecting an acidic nucleus
and a basic nucleus are present in each of the compounds, the
invention should not be construed as being limited to any one of
the isomers.
##STR00332## ##STR00333## ##STR00334## ##STR00335## ##STR00336##
##STR00337## ##STR00338## ##STR00339## ##STR00340## ##STR00341##
##STR00342## ##STR00343## ##STR00344##
[0129] Details of the method of using the sensitizing dye, for
example, selection of the structure, individual or combination use
or an amount added, can be appropriately determined in accordance
with the characteristic design of the final lithographic printing
plate.
[0130] For instance, when two or more sensitizing dyes are used in
combination, the compatibility thereof in the image-recording layer
can be increased. For the selection of sensitizing dye, the molar
absorption coefficient thereof at the emission wavelength of the
light source used is an important factor in addition to the
photosensitivity. Use of the dye having a large molar absorption
coefficient is profitable, because the amount of dye added can be
made relatively small. Also, in case of using in a lithographic
printing plate precursor, the use of such a dye is advantageous in
view of physical properties of the image-recording layer. Since the
photosensitivity and resolution of the image-recording layer and
the physical properties of the exposed area of the image-recording
layer are greatly influenced by the absorbance of sensitizing dye
at the wavelength of light source, the amount of the sensitizing
dye added is appropriately determined by taking account of these
factors.
[0131] However, for the purpose of curing a layer having a large
thickness, for example, of 5 .mu.m or more, low absorbance is
sometimes rather effective for increasing the curing degree. In the
case of using in a lithographic printing plate precursor where the
image-recording layer has a relatively small thickness, the amount
of the sensitizing dye added is preferably selected such that the
image-recording layer has an absorbance from 0.1 to 1.5, preferably
from 0.25 to 1. Ordinarily, the amount of the sensitizing dye added
is preferably from 0.05 to 30 parts by weight, more preferably from
0.1 to 20 parts by weight, most preferably from 0.2 to 10 parts by
weight, per 100 parts by weight of the total solid content of the
image-recording layer.
(2) Infrared Absorbing Agent
[0132] The infrared absorbing agent is a component used for
increasing sensitivity to an infrared laser. The infrared absorbing
agent has a function of converting the infrared ray absorbed to
heat. The infrared absorbing agent for use in the invention is
preferably a dye or pigment having an absorption maximum in a
wavelength range of 760 to 1,200 nm.
[0133] As the dye, commercially available dyes and known dyes
described in literatures, for example, Senrvo Binran (Dye Handbook)
compiled by The Society of Synthetic Organic Chemistry, Japan
(1970) can be used. Specifically, the dyes includes azo dyes, metal
complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes,
anthraquinone dyes, phthalocyanine dyes, carbonium dyes,
quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes,
pyrylium salts and metal thiolate complexes.
[0134] Examples of preferable dye include cyanine dyes described,
for example, in JP-A-58-125246, JP-A-59-84356 and JP-A-60-78787,
methine dyes described, for example, in JP-A-58-173696,
JP-A-58-181690 and JP-A-58-194595, naphthoquinone dyes described,
for example, in JP-A-58-112793, JP-A-58-224793, JP-A-59-48187,
JP-A-59-73996, JP-A-60-52940 and JP-A-60-63744, squarylium dyes
described, for example, in JP-A-58-112792, and cyanine dyes
described, for example, in British Patent 434,875.
[0135] Also, near infrared absorbing sensitizers described in U.S.
Pat. No. 5,156,938 are preferably used. Further, substituted
arylbenzo(thio)pyrylium salts described in U.S. Pat. No. 3,881,924,
trimethinethiapyrylium salts described in JP-A-57-142645
(corresponding to U.S. Pat. No. 4,327,169), pyrylium compounds
described in JP-A-58-181051, JP-A-58-220143, JP-A-59-41363,
JP-A-59-84248, JP-A-59-84249, JP-A-59-146063 and JP-A-59-146061,
cyanine dyes described in JP-A-59-216146, pentamethinethiopyrylium
salts described in U.S. Pat. No. 4,283,475, and pyrylium compounds
described in JP-B-5-13514 and JP-B-5-19702 are also preferably
used. Other preferred examples of the dye include near infrared
absorbing dyes represented by formulae (I) and (II) in U.S. Pat.
No. 4,756,993.
[0136] Other preferable examples of the infrared absorbing dye
include specific indolenine cyanine dyes described in
JP-A-2002-278057 as illustrated below.
##STR00345##
[0137] Of the dyes, cyanine dyes, squarylium dyes, pyrylium dyes,
nickel thiolate complexes and indolenine cyanine dyes are
particularly preferred. Further, cyanine dyes and indolenine
cyanine dyes are more preferred. As a particularly preferable
example of the dye, a cyanine dye represented by the following
formula (I) is exemplified.
##STR00346##
[0138] In formula (I), X.sup.1 represents a hydrogen atom, a
halogen atom, --NPh.sub.2, X.sup.2-L.sup.1 or a group shown below.
X.sup.2 represents an oxygen atom, a nitrogen atom or a sulfur
atom, L.sup.1 represents a hydrocarbon group having from 1 to 12
carbon atoms, an aromatic ring containing a hetero atom or a
hydrocarbon group having from 1 to 12 carbon atoms and containing a
hetero atom. The hetero atom indicates here a nitrogen atom, a
sulfur atom, an oxygen atom, a halogen atom or a selenium atom.
##STR00347##
(wherein Xa.sup.- has the same meaning as Za.sup.- defined
hereinafter. R.sup.a represents a substituent selected from a
hydrogen atom, an alkyl group, an aryl group, a substituted or
unsubstituted amino group and a halogen atom.)
[0139] R.sup.1 and R.sup.2 each independently represents a
hydrocarbon group having from 1 to 12 carbon atoms. In view of the
preservation stability of a coating solution for image-recording
layer, it is preferred that R.sup.1 and R.sup.2 each represents a
hydrocarbon group having two or more carbon atoms, and it is
particularly preferred that R.sup.1 and R.sup.2 are combined with
each other to form a 5-membered or 6-membered ring.
[0140] Ar.sup.1 and Ar.sup.2, which may be the same or different,
each represents an aromatic hydrocarbon group which may have a
substituent. Preferable examples of the aromatic hydrocarbon group
include a benzene ring and a naphthalene ring. Also, preferable
examples of the substituent include a hydrocarbon group having 12
or less carbon atoms, a halogen atom and an alkoxy group having 12
or less carbon atoms. Y.sup.1 and Y.sup.2, which may be the same or
different, each represents a sulfur atom or a dialkylmethylene
group having 12 or less carbon atoms. R.sup.3 and R.sup.4, which
may be the same or different, each represents a hydrocarbon group
having 20 or less carbon atoms, which may have a substituent.
Preferable examples of the substituent include an alkoxy group
having 12 or less carbon atoms, a carboxyl group and a sulfo group.
R.sup.5, R.sup.6, R.sup.7 and R.sup.8, which may be the same or
different, each represents a hydrogen atom or a hydrocarbon group
having 12 or less carbon atoms. In view of the availability of raw
materials, a hydrogen atom is preferred. Za.sup.- represents a
counter anion. However, Za.sup.- is not necessary when the cyanine
dye represented by formula (I) has an anionic substituent in the
structure thereof and neutralization of charge is not needed.
Preferable examples of the counter ion for Za.sup.- include a
halogen ion, a perchlorate ion, a tetrafluoroborate ion, a
hexafluorophosphate ion and a sulfonate ion, and particularly
preferable examples thereof include a perchlorate ion, a
hexafluorophosphate ion and an arylsulfonate ion in view of the
preservation stability of a coating solution for photosensitive
layer.
[0141] Specific examples of the cyanine dye represented by formula
(I), which can be preferably used in the invention, include those
described in Paragraph Nos. [0017] to [0019] of
JP-A-2001-133969.
[0142] Further, other particularly preferable examples include
specific indolenine cyanine dyes described in JP-A-2002-278057
described above.
[0143] Examples of the pigment for use in the invention include
commercially available pigments and pigments described in Colour
Index (C.I.), Saishin Ganrvo Binran (Handbook of the Newest
Pigments) compiled by Pigment Technology Society of Japan (1977),
Saishin Ganryo Ovou Gijutsu (Newest Application on Technologies for
Pigments), CMC Publishing Co., Ltd. (1986) and Insatsu Ink Giiutsu
(Printing Ink Technology), CMC Publishing Co., Ltd. (1984).
[0144] Examples of the pigment include black pigments, yellow
pigments, orange pigments, brown pigments, red pigments, purple
pigments, blue pigments, green pigments, fluorescent pigments,
metal powder pigments and polymer-bonded dyes. Specific examples of
usable pigment include insoluble azo pigments, azo lake pigments,
condensed azo pigments, chelated azo pigments, phthalocyanine
pigments, anthraquinone pigments, perylene and perynone pigments,
thioindigo pigments, quinacridone pigments, dioxazine pigments,
isoindolinone pigments, quinophthalone pigments, dying lake
pigments, azine pigments, nitroso pigments, nitro pigments, natural
pigments, fluorescent pigments, inorganic pigments and carbon
black. Of the pigments, carbon black is preferred.
[0145] The pigment may be used without undergoing surface treatment
or may be used after the surface treatment. For the surface
treatment, a method of coating a resin or wax on the surface, a
method of attaching a surfactant and a method of bonding a reactive
substance (for example, a silane coupling agent, an epoxy compound
or polyisocyanate) to the pigment surface. The surface treatment
methods are described in Kinzoku Sekken no Seishitsu to Oyo
(Properties and Applications of Metal Soap), Saiwai Shobo, Insatsu
Ink Giiutsu (Printing Ink Technology), CMC Publishing Co., Ltd.
(1984) and Saishin Ganrvo Oyo Giiutsu (Newest Application on
Technologies for Pigments), CMC Publishing Co., Ltd. (1986).
[0146] The pigment has a particle size of preferably from 0.01 to
10 .mu.m, more preferably from 0.05 to 1 .mu.m, particularly
preferably from 0.1 to 1 .mu.m. In the range described above, good
stability and good uniformity of the pigment dispersion in the
image-recording layer can be obtained.
[0147] For dispersing the pigment, known dispersion techniques for
use in the production of ink or toner may be used. Examples of the
dispersing machine include an ultrasonic dispersing machine, a sand
mill, an attritor, a pearl mill, a super-mill, a ball mill, an
impeller, a disperser, a KD mill, a colloid mill, a dynatron, a
three roll mill and a pressure kneader. The dispersing machines are
described in detail in Saishin Ganryo Oyo Giiutsu (Newest
Application on Technologies for Pigments), CMC Publishing Co., Ltd.
(1986).
[0148] The infrared absorbing agent may be added by being
incorporated into a microcapsule.
[0149] With respect to the amount of the infrared absorbing agent
added, the amount is so controlled that absorbance of the
image-recording layer at the maximum absorption wavelength in the
wavelength region of 760 to 1,200 nm measured by reflection
measurement is in a range of 0.3 to 1.3, preferably in a range of
0.4 to 1.2. In the range described above, the polymerization
reaction proceeds uniformly in the thickness direction of the
image-recording layer and good film strength of the image area and
good adhesion property of the image area to a support are
achieved.
[0150] The absorbance of the image-recording layer can be
controlled depending on the amount of the infrared absorbing agent
added and the thickness of the image-recording layer.
[0151] The measurement of the absorbance can be carried out in a
conventional manner. The method for measurement includes, for
example, a method of forming a image-recording layer having a
thickness determined appropriately in the range necessary for the
lithographic printing plate precursor on a reflective support, for
example, an aluminum plate, and measuring reflection density of the
image-recording layer by an optical densitometer or a
spectrophotometer according to a reflection method using an
integrating sphere.
(Chain Transfer Agent)
[0152] The image-recording layer according to the invention may
contain a chain transfer agent. The chain transfer agent
contributes to improvements in the sensitivity and preservation
stability. Compounds which function as the chain transfer agents
include, for example, compounds containing SH, PH, SiH or GeH in
their molecules. Such a compound donates hydrogen to a radical
species of low activity to generate a radical, or is oxidized and
then deprotonated to generate a radical.
[0153] In the image-recording layer according to the invention, a
thiol compound (for example, a 2-mercaptobenzimidazole, a
2-mercaptobenzothiazole, a 2-mercaptobenzoxazole, a
3-mercaptotriazole or a 5-mercaptotetrazole) is preferably used as
the chain transfer agent.
[0154] Among them, a thiol compound represented by formula (II)
shown below is particularly preferably used. By using the thiol
compound represented by formula (II) as the chain transfer agent, a
problem of the odor and decrease in sensitivity due to evaporation
of the compound from the image-recording layer or diffusion thereof
into other layers are avoided and a lithographic printing plate
precursor which is excellent in preservation stability and exhibits
high sensitivity and good printing durability is obtained.
##STR00348##
[0155] In formula (II), R represents an alkyl group which may have
a substituent or an aryl group which may have a substituent; and A
represents an atomic group necessary for forming a 5-membered or
6-membered hetero ring containing a carbon atom together with the
N.dbd.C--N linkage, and A may have a substituent.
[0156] Compounds represented by formulae (IIA) and (IIB) shown
below are more preferably used.
##STR00349##
[0157] In formulae (IIA) and (IIB), R represents an alkyl group
which may have a substituent or an aryl group which may have a
substituent; and X represents a hydrogen atom, a halogen atom, an
alkoxy group which may have a substituent, an alkyl group which may
have a substituent or an aryl group which may have a
substituent.
[0158] Specific examples of the compound represented by formula
(II) are set forth below, but the invention should not be construed
as being limited thereto.
##STR00350## ##STR00351## ##STR00352## ##STR00353## ##STR00354##
##STR00355## ##STR00356## ##STR00357## ##STR00358##
[0159] The amount of the chain transfer agent (for example, the
thiol compound) used is preferably from 0.01 to 20% by weight, more
preferably from 0.1 to 15% by weight, still more preferably from
1.0 to 10% by weight, based on the total solid content of the
image-recording layer.
(Microcapsule)
[0160] In the invention, in order to incorporate the
above-described constituting components of the image-recording
layer and other constituting components described hereinafter into
the image-recording layer, a part or whole of the constituting
components is encapsulated into microcapsules and added to the
image-recording layer as described, for example, in
JP-A-2001-277740 and JP-A-2001-277742. In such a case, each
constituting component may be present inside or outside the
microcapsule in an appropriate ratio.
[0161] As a method of microencapsulating the constituting
components of the image-recording layer, known methods can be used.
Methods for the production of microcapsules include, for example, a
method of utilizing coacervation described in U.S. Pat. Nos.
2,800,457 and 2,800,458, a method of using interfacial
polymerization described in U.S. Pat. No. 3,287,154, JP-B-38-19574
and JP-B-42-446, a method of using deposition of polymer described
in U.S. Pat. Nos. 3,418,250 and 3,660,304, a method of using an
isocyanate polyol wall material described in U.S. Pat. No.
3,796,669, a method of using an isocyanate wall material described
in U.S. Pat. No. 3,914,511, a method of using a
urea-formaldehyde-type or urea-formaldehyde-resorcinol-type
wall-forming material described in U.S. Pat. Nos. 4,001,140,
4,087,376 and 4,089,802, a method of using a wall material, for
example, a melamine-formaldehyde resin or hydroxycellulose
described in U.S. Pat. No. 4,025,445, an in-situ method by
polymerization of monomer described in JP-B-36-9163 and
JP-B-51-9079, a spray drying method described in British Patent
930,422 and U.S. Pat. No. 3,111,407, and an electrolytic dispersion
cooling method described in British Patents 952,807 and 967,074,
but the invention should not be construed as being limited
thereto.
[0162] A preferable microcapsule wall used in the invention has
three-dimensional crosslinking and has a solvent-swellable
property. From this point of view, a preferable wall material of
the microcapsule includes polyurea, polyurethane, polyester,
polycarbonate, polyamide and a mixture thereof, and particularly
polyurea and polyurethane are preferred. Further, a compound having
a crosslinkable functional group, for example, an ethylenically
unsaturated bond, capable of being introduced into the binder
polymer described above may be introduced into the microcapsule
wall.
[0163] The average particle size of the microcapsule is preferably
from 0.01 to 3.0 .mu.m, more preferably from 0.05 to 2.0 .mu.m,
particularly preferably from 0.10 to 1.0 .mu.m. In the range
described above, preferable resolution and good preservation
stability can be achieved.
(Surfactant)
[0164] In the invention, it is preferred to use a surfactant in the
image-recording layer in order to progress the developing property
and to improve the state of surface coated. The surfactant
includes, for example, a nonionic surfactant, an anionic
surfactant, a cationic surfactant, an amphoteric surfactant and a
fluorine-based surfactant. The surfactants may be used individually
or in combination of two or more thereof.
[0165] The nonionic surfactant used in the invention is not
particular restricted, and nonionic surfactants hitherto known can
be used. Examples of the nonionic surfactant include
polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers,
polyoxyethylene polystyryl phenyl ethers, polyoxyethylene
polyoxypropylene alkyl ethers, glycerin fatty acid partial esters,
sorbitan fatty acid partial esters, pentaerythritol fatty acid
partial esters, propylene glycol monofatty acid esters, sucrose
fatty acid partial esters, polyoxyethylene sorbitan fatty acid
partial esters, polyoxyethylene sorbitol fatty acid partial esters,
polyethylene glycol fatty acid esters, polyglycerol fatty acid
partial esters, polyoxyethylenated castor oils, polyoxyethylene
glycerol fatty acid partial esters, fatty acid diethanolamides,
N,N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines,
triethanolamine fatty acid esters, trialylamine oxides,
polyethylene glycols and copolymers of polyethylene glycol and
polypropylene glycol.
[0166] The anionic surfactant used in the invention is not
particularly restricted and anionic surfactants hitherto known can
be used. Examples of the anionic surfactant include fatty acid
salts, abietic acid salts, hydroxyalkanesulfonic acid salts,
alkanesulfonic acid salts, dialkylsulfosuccinic ester salts,
straight-chain alkylbenzenesulfonic acid salts, branched
alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid
salts, alkylphenoxypolyoxy ethylene propylsulfonic acid salts,
polyoxyethylene alkylsulfophenyl ether salts,
N-methyl-N-oleyltaurine sodium salt, N-alkylsulfosuccinic monoamide
disodium salts, petroleum sulfonic acid salts, sulfated beef tallow
oil, sulfate ester slats of fatty acid alkyl ester, alkyl sulfate
ester salts, polyoxyethylene alkyl ether sulfate ester salts, fatty
acid monoglyceride sulfate ester salts, polyoxyethylene alkyl
phenyl ether sulfate ester salts, polyoxyethylene styrylphenyl
ether sulfate ester salts, alkyl phosphate ester salts,
polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene
alkyl phenyl ether phosphate ester salts, partial saponification
products of styrene/maleic anhydride copolymer, partial
saponification products of olefin/maleic anhydride copolymer and
naphthalene sulfonate formalin condensates.
[0167] The cationic surfactant used in the invention is not
particularly restricted and cationic surfactants hitherto known can
be used. Examples of the cationic surfactant include alkylamine
salts, quaternary ammonium salts, polyoxyethylene alkyl amine salts
and polyethylene polyamine derivatives.
[0168] The amphoteric surfactant used in the invention is not
particularly restricted and amphoteric surfactants hitherto known
can be used. Examples of the amphoteric surfactant include
carboxybetaines, aminocarboxylic acids, sulfobetaines,
aminosulfuric esters and imidazolines.
[0169] In the surfactants described above, the term
"polyoxyethylene" can be replaced with "polyoxyalkylene", for
example, polyoxymethylene, polyoxypropylene or polyoxybutylene, and
such surfactants can also be used in the invention.
[0170] Further, a preferable surfactant includes a fluorine-based
surfactant containing a perfluoroalkyl group in its molecule.
Examples of the fluorine-based surfactant include an anionic type,
for example, perfluoroalkyl carboxylates, perfluoroalkyl sulfonates
or perfluoroalkylphosphates; an amphoteric type, for example,
perfluoroalkyl betaines; a cationic type, for example,
perfluoroalkyl trimethyl ammonium salts; and a nonionic type, for
example, perfluoroalkyl amine oxides, perfluoroalkyl ethylene oxide
adducts, oligomers having a perfluoroalkyl group and a hydrophilic
group, oligomers having a perfluoroalkyl group and an oleophilic
group, oligomers having a perfluoroalkyl group, a hydrophilic group
and an oleophilic group or urethanes having a perfluoroalkyl group
and an oleophilic group. Further, fluorine-based surfactants
described in JP-A-62-170950, JP-A-62-226143 and JP-A-60-168144 are
also preferably exemplified.
[0171] The content of the surfactant is preferably from 0.001 to
10% by weight, more preferably from 0.01 to 7% by weight, based on
the total solid content of the image-recording layer.
(Hydrophilic Polymer)
[0172] In the invention, a hydrophilic polymer may be incorporated
into the image-recording layer in order to improve the developing
property and dispersion stability of microcapsule.
[0173] Preferable examples of the hydrophilic polymer include those
having a hydrophilic group, for example, a hydroxy group, a
carboxyl group, a carboxylate group, a hydroxyethyl group, a
polyoxyethyl group, a hydroxypropyl group, a polyoxypropyl group,
an amino group, an aminoethyl group, an aminopropyl group, an
ammonium group, an amido group, a carboxymethyl group, a sulfonic
acid group and a phosphoric acid group.
[0174] Specific examples of the hydrophilic polymer include gum
arabic, casein, gelatin, a starch derivative, carboxymethyl
cellulose or a sodium salt thereof, cellulose acetate, sodium
alginate, a vinyl acetate-maleic acid copolymer, a styrene-maleic
acid copolymer, polyacrylic acid or a salt thereof, polymethacrylic
acid or a salt thereof, a homopolymer or copolymer of hydroxyethyl
methacrylate, a homopolymer or copolymer of hydroxyethyl acrylate,
a homopolymer or copolymer of hydroxypropyl methacrylate, a
homopolymer or copolymer of hydroxypropyl acrylate, a homopolymer
or copolymer of hydroxybutyl methacrylate, a homopolymer or
copolymer of hydroxybutyl acrylate, polyethylene glycol, a
hydroxypropylene polymer, polyvinyl alcohol, a hydrolyzed polyvinyl
acetate having a hydrolysis degree of 60% by mole or more,
preferably 80% by mole or more, polyvinyl formal, polyvinyl
butyral, polyvinyl pyrrolidone, a homopolymer or polymer of
acrylamide, a homopolymer or copolymer of methacrylamide, a
homopolymer or copolymer of N-methylolacrylamide, polyvinyl
pyrrolidone, an alcohol-soluble nylon, and a polyether of
2,2-bis(4-hydroxyphenyl)propane with epichlorohydrin.
[0175] The hydrophilic polymer preferably has a weight average
molecular weight of 5,000 or more, more preferably from 10,000 to
300,000. The hydrophilic polymer may be any of a random polymer, a
block polymer, a graft polymer or the like.
[0176] The content of the hydrophilic polymer is preferably 20% by
weight or less, more preferably 10% by weight or less, based on the
total solid content of the image-recording layer.
(Coloring Agent)
[0177] In the invention, a dye having large absorption in the
visible light region can be used as a coloring agent for the image.
Specific examples thereof include Oil Yellow #101, Oil Yellow #103,
Oil Pink #312, Oil Green BG, Oil Blue BOS, Oil Blue #603, Oil Black
BY, Oil Black BS, Oil Black T-505 (produced by Orient Chemical
Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555),
Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI45170B),
Malachite Green (CI42000), Methylene Blue (CI52015), and dyes
described in JP-A-62-293247. Also, a pigment, for example,
phthalocyanine-based pigment, azo-based pigment, carbon black and
titanium oxide can be preferably used.
[0178] It is preferable to add the coloring agent, because the
image area and the non-image area after the image formation can be
easily distinguished. The amount of the coloring agent added is
preferably from 0.01 to 10% by weight based on the total solid
content of the image-recording layer.
(Print-Out Agent)
[0179] In the image-recording layer according to the invention, a
compound capable of undergoing discoloration by the effect of an
acid or a radical can be added in order to form a print-out image.
As such a compound, for example, various dyes, e.g.,
diphenylmethane-based, triphenylmethane-based, thiazine-based,
oxazine-based, xanthene-based, anthraquinone-based,
iminoquinone-based, azo-based and azomethine-based dyes are
effectively used.
[0180] Specific examples thereof include dyes, for example,
Brilliant Green, Ethyl Violet, Methyl Green, Crystal Violet, Basic
Fuchsine, Methyl Violet 2B, Quinaldine Red, Rose Bengale, Metanil
Yellow, Thymolsulfophthalein, Xylenol Blue, Methyl Orange,
Paramethyl Red, Congo Red, Benzopurpurine 4B, .alpha.-Naphthyl Red,
Nile Blue 2B, Nile Blue A, Methyl Violet, Malachite Green,
Parafuchsine, Victoria Pure Blue BOH (produced by Hodogaya Chemical
Co., Ltd.), Oil Blue #603 (produced by Orient Chemical Industry
Co., Ltd.), Oil Pink #312 (produced by Orient Chemical Industry
Co., Ltd.), Oil Red 5B (produced by Orient Chemical Industry Co.,
Ltd.), Oil Scarlet #308 (produced by Orient Chemical Industry Co.,
Ltd.), Oil Red OG (produced by Orient Chemical Industry Co., Ltd.),
Oil Red RR (produced by Orient Chemical Industry Co., Ltd.), Oil
Green #502 (produced by Orient Chemical Industry Co., Ltd.), Spiron
Red BEH Special (produced by Hodogaya Chemical Co., Ltd.), m-Cresol
Purple, Cresol Red, Rhodamine B, Rhodamine 6G, Sulforhodamine B,
Auramine, 4-p-diethylaminophenyliminonaphthoquinone,
2-carboxyanilino-4-p-diethylaminophenyliminonaphthoquinone,
2-carboxystearylamino-4-p-N,N-bis(hydroxyethyl)aminophenyliminonaphthoqui-
none, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone
and 1-.beta.-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone, and
leuco dyes, for example, p,p',p''-hexamethyltriaminotriphenyl
methane (leuco Crystal Violet) and Pergascript Blue SRB (produced
by Ciba Geigy).
[0181] Other preferable examples include leuco dyes known as a
material for heat-sensitive paper or pressure-sensitive paper.
Specific examples thereof include Crystal Violet Lactone, Malachite
Green Lactone, Benzoyl Leuco Methylene Blue,
2-(N-phenyl-N-methylamino)-6-(N-p-tolyl-N-ethyl)aminofluorane,
2-anilino-3-methyl-6-(N-ethyl-p-toluidino)fluorane,
3,6-dimethoxyfluorane,
3-(N,N-diethylamino)-5-methyl-7-(N,N-dibenzylamino)fluorane,
3-(N-cyclohexyl-N-methylamino)-6-methyl-7-anilinofluorane,
3-(N,N-diethylamino)-6-methyl-7-anilinofluorane,
3-(N,N-diethylamino)-6-methyl-7-xylidino-fluorane,
3-(N,N-diethylamino)-6-methyl-7-chlorofluorane,
3-(N,N-diethylamino)-6-methoxy-7-aminofluorane,
3-(N,N-diethylamino)-7-(4-chloroanilino)fluorane,
3-(N,N-diethylamino)-7-chlorofluorane,
3-(N,N-diethylamino)-7-benzylaminofluorane,
3-(N,N-diethylamino)-7,8-benzofluorane,
3-(N,N-dibutylamino)-6-methyl-7-anilinofluorane,
3-(N,N-dibutylamino)-6-methyl-7-xylidinofluorane,
3-piperidino-6-methyl-7-anilinofluorane,
3-pyrrolidino-6-methyl-7-anilinofluorane,
3,3-bis(1-ethyl-2-methylindol-3-yl)phthalide,
3,3-bis(1-n-butyl-2-methylindol-3-yl)phthalide,
3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide,
3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-phthal-
ide and
3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide.
[0182] The dye capable of undergoing discoloration by the effect of
an acid or a radical is preferably added in an amount of 0.01 to
15% by weight based on the total solid content of the
image-recording layer.
(Polymerization Inhibitor)
[0183] It is preferred that a small amount of a thermal
polymerization inhibitor is added to the image-recording layer
according to the invention in order to inhibit undesirable thermal
polymerization of the polymerizable compound during the production
or preservation of the image-recording layer.
[0184] The thermal polymerization inhibitor preferably includes,
for example, hydroquinone, p-methoxyphenol, di-tert-butyl-p-cresol,
pyrogallol, tert-butyl catechol, benzoquinone,
4,4'-thiobis(3-methyl-6-tert-butylphenol),
2,2'-methylenebis(4-methyl-6-tert-butylphenol) and
N-nitroso-N-phenylhydroxylamine aluminum salt.
[0185] The amount of the thermal polymerization inhibitor added is
preferably from about 0.01 to about 5% by weight based on the total
solid content of the image-recording layer.
(Higher Fatty Acid Derivative)
[0186] In the image-recording layer according to the invention, for
example, a higher fatty acid derivative, e.g., behenic acid or
behenic acid amide may be added and localized on the surface of the
image-recording layer during the process of drying after coating in
order to avoid polymerization inhibition due to oxygen. The amount
of the higher fatty acid derivative added is preferably from about
0.1 to about 10% by weight based on the total solid content of the
image-recording layer.
(Plasticizer)
[0187] The image-recording layer according to the invention may
contain a plasticizer. Preferable examples of the plasticizer
include a phthalic acid ester, for example, dimethyl phthalate,
diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, diocyl
phthalate, octyl capryl phthalate, dicyclohexyl phthalate,
ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate
or diallyl phthalate; a glycol ester, for example, dimethyl glycol
phthalate, ethyl phthalylethyl glycolate, methyl phthalylethyl
glycolate, butyl phthalylbutyl glycolate or triethylene glycol
dicaprylic acid ester; a phosphoric acid ester, for example,
tricresyl phosphate or triphenyl phosphate; an aliphatic dibasic
acid ester, for example, diisobutyl adipate, dioctyl adipate,
dimethyl sebacate, dibutyl sebacate, dioctyl azelate or dibutyl
maleate; polyglycidyl methacrylate, triethyl citrate, glycerin
triacetyl ester and butyl laurate. The content of the plasticizer
is preferably about 30% by weight or less based on the total solid
content of the image-recording layer.
(Fine Inorganic Particle)
[0188] The image-recording layer according to the invention may
contain fine inorganic particle in order to increase strength of
the cured layer in the image area. The fine inorganic particle
preferably includes, for example, silica, alumina, magnesium oxide,
titanium oxide, magnesium carbonate, calcium alginate and a mixture
thereof. Even if the fine inorganic particle has no light to heat
converting property, it can be used, for example, for strengthening
the layer or enhancing interface adhesion property due to surface
roughening. The fine inorganic particle preferably has an average
particle size from 5 nm to 10 .mu.m, more preferably from 0.5 to 3
.mu.m. In the range described above, it is stably dispersed in the
image-recording layer, sufficiently maintains the film strength of
the image-recording layer and can form the non-image area excellent
in hydrophilicity and preventing from the occurrence of stain at
the printing.
[0189] The fine inorganic particle described above is easily
available as a commercial product, for example, colloidal silica
dispersion.
[0190] The content of the fine inorganic particle is preferably 20%
by weight or less, more preferably 10% by weight or less, based on
the total solid content of the image-recording layer.
(Hydrophilic Low Molecular Weight Compound)
[0191] The image-recording layer according to the invention may
contain a hydrophilic low molecular weight compound in order to
improve the developing property. The hydrophilic low molecular
weight compound includes a water-soluble organic compound, for
example, a glycol compound, e.g., ethylene glycol, diethylene
glycol, triethylene glycol, propylene glycol, dipropylene glycol or
tripropylene glycol, or an ether or ester derivative thereof, a
polyhydroxy compound, e.g., glycerine or pentaerythritol, an
organic amine, e.g., triethanol amine, diethanol amine or
monoethanol amine, or a salt thereof, an organic sulfonic acid,
e.g., toluene sulfonic acid or benzene sulfonic acid, or a salt
thereof, an organic phosphonic acid, e.g., phenyl phosphonic acid,
or a salt thereof, an organic carboxylic acid, e.g., tartaric acid,
oxalic acid, citric acid, maleic acid, lactic acid, gluconic acid
or an amino acid, or a salt thereof, and an organic quaternary
ammonium salt, e.g., tetraethyl ammonium hydrochloride.
[Lithographic Printing Plate Precursor]
[0192] Next, a method for preparation of a lithographic printing
plate precursor is described in more detail below. The lithographic
printing plate precursor of the invention comprises a undercoat
layer, an image-recording layer and a support and is prepared by
appropriately providing a protective layer or a backcoat layer
depending on the use.
(Formation of Image-Recording Layer)
[0193] The image-recording layer according to the invention is
formed by dispersing or dissolving each of the necessary
constituting components described above to prepare a coating
solution and coating the solution. The solvent used include, for
example, ethylene dichloride, cyclohexanone, methyl ethyl ketone,
methanol, ethanol, propanol, ethylene glycol monomethyl ether,
1-methoxy-2-propanol, 2-methxyethyl acetate, 1-methoxy-2-propyl
acetate, dimethoxyethane, methyl lactate, ethyl lactate,
N,N-dimethylacetamide, N,N-dimethylformamide, tetramethylurea,
N-methylpyrrolidone, dimethylsulfoxide, sulfolane,
.gamma.-butyrolactone, toluene and water, but the invention should
not be construed as being limited thereto. The solvents may be used
individually or as a mixture. The solid concentration of the
coating solution is preferably from 1 to 50% by weight.
[0194] The image-recording layer according to the invention may
also be formed by preparing plural coating solutions by dispersing
or dissolving the same or different components described above into
the same or different solvents and conducting repeatedly plural
coating and drying.
[0195] The coating amount (solid content) of the image-recording
layer after the coating and drying may be varied depending on the
use, but ordinarily, it is preferably from 0.3 to 3.0 g/m.sup.2. In
the range described above, the preferable sensitivity and good film
property of the image-recording layer can be obtained.
[0196] Various methods can be used for the coating. Examples of the
method include bar coater coating, spin coating, spray coating,
curtain coating, dip coating, air knife coating, blade coating and
roll coating.
(Support)
[0197] The support for use in the lithographic printing plate
precursor according to the invention is not particularly restricted
as long as it is a dimensionally stable plate-like hydrophilic
support. The support includes, for example, paper, paper laminated
with plastic (for example, polyethylene, polypropylene or
polystyrene), a metal plate (for example, aluminum, zinc or copper
plate), a plastic film (for example, cellulose diacetate, cellulose
triacetate, cellulose propionate, cellulose butyrate, cellulose
acetatebutyrate, cellulose nitrate, polyethylene terephthalate,
polyethylene, polystyrene, polypropylene, polycarbonate or
polyvinyl acetal film) and paper or a plastic film laminated or
deposited with the metal described above. Preferable examples of
the support include a polyester film and an aluminum plate. Among
them, the aluminum plate is preferred since it has good dimensional
stability and is relatively inexpensive.
[0198] The aluminum plate includes a pure aluminum plate, an alloy
plate comprising aluminum as a main component and containing a
trace amount of hetero elements and a thin film of aluminum or
aluminum alloy laminated with plastic. The hetero element contained
in the aluminum alloy includes, for example, silicon, iron,
manganese, copper, magnesium, chromium, zinc, bismuth, nickel and
titanium. The content of the hetero element in the aluminum alloy
is preferably 10% by weight or less. Although a pure aluminum plate
is preferred in the invention, since completely pure aluminum is
difficult to be produced in view of the refining technique, the
aluminum plate may slightly contain the hetero element. The
composition is not specified for the aluminum plate and those
materials known and used conventionally can be appropriately
utilized.
[0199] The thickness of the support is preferably from 0.1 to 0.6
mm, more preferably from 0.15 to 0.4 mm, still more preferably from
0.2 to 0.3 mm.
[0200] Prior to the use of aluminum plate, a surface treatment, for
example, roughening treatment or anodizing treatment is preferably
performed. The surface treatment facilitates improvement in the
hydrophilic property and ensures adhesion between the
image-recording layer and the support. In advance of the roughening
treatment of the aluminum plate, a degreasing treatment, for
example, with a surfactant, an organic solvent or an aqueous
alkaline solution is conducted for removing rolling oil on the
surface thereof, if desired.
[0201] The roughening treatment of the surface of the aluminum
plate is conducted by various methods and includes, for example,
mechanical roughening treatment, electrochemical roughening
treatment (roughening treatment of electrochemically dissolving the
surface) and chemical roughening treatment (roughening treatment of
chemically dissolving the surface selectively).
[0202] As the method of the mechanical roughening treatment, a
known method, for example, a ball grinding method, a brush grinding
method, a blast grinding method or a buff grinding method can be
used.
[0203] The electrochemical roughening treatment method includes,
for example, a method of conducting it by passing alternating
current or direct current in an electrolyte containing an acid, for
example, hydrochloric acid or nitric acid. Also, a method of using
a mixed acid described in JP-A-54-63902 can be used.
[0204] The aluminum plate after the roughening treatment is then
subjected, if desired, to an alkali etching treatment using an
aqueous solution, for example, of potassium hydroxide or sodium
hydroxide and further subjected to a neutralizing treatment, and
then subjected to an anodizing treatment in order to enhance the
abrasion resistance, if desired.
[0205] As the electrolyte used for the anodizing treatment of the
aluminum plate, various electrolytes capable of forming porous
oxide film can be used. Ordinarily, sulfuric acid, hydrochloric
acid, oxalic acid, chromic acid or a mixed acid thereof is used.
The concentration of the electrolyte can be appropriately
determined depending on the kind of the electrolyte.
[0206] Since the conditions of the anodizing treatment are varied
depending on the electrolyte used, they cannot be defined
generally. However, it is ordinarily preferred that electrolyte
concentration in the solution is from 1 to 80% by weight, liquid
temperature is from to 70.degree. C., current density is from 5 to
60 A/dm.sup.2, voltage is from 1 to 100 V, and electrolysis time is
from 10 seconds to 5 minutes. The amount of the anodized film
formed is preferably from 1.0 to 5.0 g/m.sup.2, more preferably
from 1.5 to 4.0 g/m.sup.2. In the range described above, good
printing durability and favorable scratch resistance in the
non-image area of lithographic printing plate can be achieved.
[0207] The aluminum plate subjected to the surface treatment and
having the anodized film is used as it is as the support in the
invention. However, in order to more improve an adhesion property
to a layer provided thereon, hydrophilicity, resistance to stain,
heat insulating property or the like, other treatment, for example,
a treatment for enlarging micropores or a sealing treatment of
micropores of the anodized film described in JP-A-2001-253181 and
JP-A-2001-322365, or a surface hydrophilizing treatment by
immersing in an aqueous solution containing a hydrophilic compound,
may be appropriately conducted. Needless to say, the enlarging
treatment and sealing treatment are not limited to those described
in the above-described patents and any conventionally known method
may be employed.
[0208] As the sealing treatment, as well as a sealing treatment
with steam, a sealing treatment with an aqueous solution containing
an inorganic fluorine compound, for example, fluorozirconic acid
alone or sodium fluoride, a sealing treatment with steam having
added thereto lithium chloride or a sealing treatment with hot
water may be employed.
[0209] Among them, the sealing treatment with an aqueous solution
containing an inorganic fluorine compound, the sealing treatment
with water vapor and the sealing treatment with hot water are
preferred.
[0210] The hydrophilizing treatment includes an alkali metal
silicate method described in U.S. Pat. Nos. 2,714,066, 3,181,461,
3,280,734 and 3,902,734. In the method, the support is subjected to
an immersion treatment or an electrolytic treatment in an aqueous
solution, for example, of sodium silicate. In addition, the
hydrophilizing treatment includes, for example, a method of
treating with potassium fluorozirconate described in JP-B-36-22063
and a method of treating with polyvinylphosphonic acid described in
U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689,272.
[0211] In the case of using a support having a surface of
insufficient hydrophilicity, for example, a polyester film, in the
invention, it is desirable to coat a hydrophilic layer thereon to
make the surface sufficiently hydrophilic. Examples of the
hydrophilic layer preferably includes a hydrophilic layer formed by
coating a coating solution containing a colloid of oxide or
hydroxide of at least one element selected from beryllium,
magnesium, aluminum, silicon, titanium, boron, germanium, tin,
zirconium, iron, vanadium, antimony and a transition metal
described in JP-A-2001-199175, a hydrophilic layer containing an
organic hydrophilic matrix obtained by crosslinking or
pseudo-crosslinking of an organic hydrophilic polymer described in
JP-A-2002-79772, a hydrophilic layer containing an inorganic
hydrophilic matrix obtained by sol-gel conversion comprising
hydrolysis and condensation reaction of polyalkoxysilane and
titanate, zirconate or aluminate, and a hydrophilic layer
comprising an inorganic thin layer having a surface containing
metal oxide. Among them, the hydrophilic layer formed by coating a
coating solution containing a colloid of oxide or hydroxide of
silicon is preferred.
[0212] Further, in the case of using, for example, a polyester film
as the support in the invention, it is preferred to provide an
antistatic layer on the hydrophilic layer side, opposite side to
the hydrophilic layer or both sides. When the antistatic layer is
provided between the support and the hydrophilic layer, it also
contributes to improve the adhesion property of the hydrophilic
layer to the support. As the antistatic layer, a polymer layer
having fine particles of metal oxide or a matting agent dispersed
therein described in JP-A-2002-79772 can be used.
[0213] The support preferably has a center line average roughness
of its surface of 0.10 to 1.2 .mu.m. In the range described above,
good adhesion property to the image-recording layer, good printing
durability, and good resistance to stain can be achieved.
[0214] The color density of the support is preferably from 0.15 to
0.65 in terms of the reflection density value. In the range
described above, good image-forming property by preventing halation
at the image exposure and good aptitude for plate inspection after
development can be achieved.
(Protective Layer)
[0215] In the lithographic printing plate precursor according to
the invention, a protective layer (oxygen-blocking layer) is
preferably provided on the image-recording layer in order to
prevent diffusion and penetration of oxygen which inhibits the
polymerization reaction at the time of exposure. The protective
layer for use in the invention preferably has oxygen permeability
(A) at 25.degree. C. under one atmosphere of
1.0.ltoreq.(A).ltoreq.20 (ml/m.sup.2day). When the oxygen
permeability (A) is extremely lower than 1.0 (ml/m.sup.2day),
problems may occur in that an undesirable polymerization reaction
arises during the production or preservation before image exposure
and in that undesirable fog or spread of image line occurs at the
image exposure. On the contrary, when the oxygen permeability (A)
greatly exceeds 20 (ml/m.sup.2day), decrease in sensitivity may be
incurred. The oxygen permeability (A) is more preferably in a range
of 1.5.ltoreq.(A).ltoreq.12 (ml/m.sup.2day), still more preferably
in a range of 2.0.ltoreq.(A).ltoreq.10.0 (ml/m.sup.2day). Besides
the above described oxygen permeability, as for the characteristics
required of the protective layer, it is desired that the protective
layer does not substantially hinder the transmission of light for
the exposure, is excellent in the adhesion property to the
image-recording layer, and can be easily removed during a
development step after the exposure. Contrivances on the protective
layer have been heretofore made and described in detail in U.S.
Pat. No. 3,458,311 and JP-B-55-49729.
[0216] As the material of the protective layer, a water-soluble
polymer compound relatively excellent in crystallizability is
preferably used. Specifically, a water-soluble polymer, for
example, polyvinyl alcohol, vinyl alcohol/vinyl phthalate
copolymer, vinyl acetate/vinyl alcohol/vinyl phthalate copolymer,
vinyl acetate/crotonic acid copolymer, polyvinyl pyrrolidone,
acidic cellulose, gelatin, gum arabic, polyacrylic acid or
polyacrylamide is enumerated. The water-soluble polymer compounds
may be used individually or as a mixture. Of the compounds, when
polyvinyl alcohol is used as a main component, the best results can
be obtained in the fundamental characteristics, for example,
oxygen-blocking property and removability of the protective layer
by development.
[0217] Polyvinyl alcohol for use in the protective layer may be
partially substituted with ester, ether or acetal as long as it
contains unsubstituted vinyl alcohol units for achieving the
necessary oxygen-blocking property and water solubility. Also, a
part of polyvinyl alcohol may have other copolymer component. As
specific examples of the polyvinyl alcohol, those having a
hydrolyzing rate of 71 to 100% and a polymerization repeating unit
number of 300 to 2,400 are exemplified. Specific examples thereof
include PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124,
PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205,
PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E,
PVA-224E, PVA-405, PVA-420, PVA-613 and L-8 (produced by Kuraray
Co., Ltd.). They can be used individually or as a mixture.
According to a preferred embodiment, the content of polyvinyl
alcohol in the protective layer is from 20 to 95% by weight, more
preferably from 30 to 90% by weight.
[0218] Also, known modified polyvinyl alcohol can be preferably
used. For instance, polyvinyl alcohols of various polymerization
degrees having at random a various kind of hydrophilic modified
cites, for example, an anion-modified cite modified with an anion,
e.g., a carboxyl group or a sulfo group, a cation-modified cite
modified with a cation, e.g., an amino group or an ammonium group,
a silanol-modified cite or a thiol-modified cite, and polyvinyl
alcohols of various polymerization degrees having at the terminal
of the polymer a various kind of modified cites, for example, the
above-described anion-modified cite, cation modified cite,
silanol-modified cite or thiol-modified cite, an alkoxy-modified
cite, a sulfide-modified cite, an ester modified cite of vinyl
alcohol with a various kind of organic acids, an ester modified
cite of the above-described anion-modified cite with an alcohol or
an epoxy-modified cite are exemplified.
[0219] As a component used as a mixture with polyvinyl alcohol,
polyvinyl pyrrolidone or a modified product thereof is preferable
from the viewpoint of the oxygen-blocking property and removability
by development. The content thereof is ordinarily from 3.5 to 80%
by weight, preferably from 10 to 60% by weight, more preferably
from 15 to 30% by weight, in the protective layer.
[0220] The components of the protective layer (selection of PVA and
use of additives) and the coating amount are determined taking into
consideration fogging prevention property, adhesion property and
scratch resistance besides the oxygen-blocking property and
removability by development. In general, the higher the hydrolyzing
rate of the PVA used (the higher the unsubstituted vinyl alcohol
unit content in the protective layer) and the larger the layer
thickness, the higher is the oxygen-blocking property, thus it is
advantageous in the point of sensitivity. The molecular weight of
the polymer, for example, polyvinyl alcohol (PVA) is ordinarily
from 2,000 to 10,000,000, preferably from 20,000 to 3,000,000.
[0221] As other additive of the protective layer, glycerin,
dipropylene glycol or the like can be added in an amount
corresponding to several % by weight of the polymer to provide
flexibility. Further, an anionic surfactant, for example, sodium
alkylsulfate or sodium alkylsulfonate; an amphoteric surfactant,
for example, alkylaminocarboxylate and alkylaminodicarboxylate; or
a nonionic surfactant, for example, polyoxyethylene alkyl phenyl
ether can be added in an amount corresponding to several % by
weight of the polymer.
[0222] The adhesion property of the protective layer to the
image-recording layer and scratch resistance are also extremely
important in view of handling of the printing plate precursor.
Specifically, when a hydrophilic layer comprising a water-soluble
polymer is laminated on the oleophilic image-recording layer, layer
peeling due to an insufficient adhesion property is liable to
occur, and the peeled portion causes such a defect as failure in
curing of the image-recording layer due to polymerization
inhibition by oxygen. Various proposals have been made for
improving the adhesion property between the image-recording layer
and the protective layer. For example, it is described in U.S.
patent application Ser. Nos. 292,501 and 44,563 that a sufficient
adhesion property can be obtained by mixing from 20 to 60% by
weight of an acryl-based emulsion or a water-insoluble vinyl
pyrrolidone/vinyl acetate copolymer with a hydrophilic polymer
mainly comprising polyvinyl alcohol and laminating the resulting
mixture on the image-recording layer. Any of these known techniques
can be applied to the protective layer according to the invention.
Coating methods of the protective layer are described in detail,
for example, in U.S. Pat. No. 3,458,311 and JP-B-55-49729.
[0223] Further, it is also preferred to incorporate an inorganic
stratiform compound into the protective layer of the lithographic
printing plate precursor according to the invention for the purpose
of improving the oxygen-blocking property and property for
protecting the surface of image-recording layer.
[0224] The inorganic stratiform compound used here is a particle
having a thin tabular shape and includes, for instance, mica, for
example, natural mica represented by the following formula: A (B,
C).sub.2-5 D.sub.4O.sub.10 (OH, F, O).sub.2, (wherein A represents
any one of K, Na and Ca, B and C each represents any one of Fe
(II), Fe(III), Mn, Al, Mg and V, and D represents Si or Al) or
synthetic mica; talc represented by the following formula:
3MgO.4SiO.H.sub.2O; teniolite; montmorillonite; saponite;
hectolite; and zirconium phosphate.
[0225] Of the micas, examples of the natural mica include
muscovite, paragonite, phlogopite, biotite and lepidolite. Examples
of the synthetic mica include non-swellable mica, for example,
fluorphlogopite KMg.sub.3(AlSi.sub.3O.sub.10)F.sub.2 or potassium
tetrasilic mica KMg.sub.2.5(Si.sub.4O.sub.10)F.sub.2, and swellable
mica, for example, Na tetrasilic mica
NaMg.sub.2.5(Si.sub.4O.sub.10)F.sub.2, Na or Li teniolite (Na,
Li)Mg.sub.2Li(Si.sub.4O.sub.10)F.sub.2, or montmorillonite based Na
or Li hectolite (Na,
Li).sub.1/8Mg.sub.2/5Li.sub.1/8(Si.sub.4O.sub.10)F.sub.2. Synthetic
smectite is also useful.
[0226] Of the inorganic stratiform compounds, fluorine based
swellable mica, which is a synthetic inorganic stratiform compound,
is particularly useful in the invention. Specifically, the
swellable synthetic mica and an swellable clay mineral, for
example, montmorillonite, saponite, hectolite or bentonite have a
stratiform structure comprising a unit crystal lattice layer having
thickness of approximately 10 to 15 angstroms, and metallic atom
substitution in the lattices thereof is remarkably large in
comparison with other clay minerals. As a result, the lattice layer
results in lack of positive charge and in order to compensate it, a
cation, for example, Na.sup.+, Ca.sup.2+ or Mg.sup.2+, is adsorbed
between the lattice layers. The cation existing between the lattice
layers is referred to as an exchangeable cation and is exchangeable
with various cations. In particular, in the case where the cation
between the lattice layers is Li+ or Na.sup.+, because of a small
ionic radius, a bond between the stratiform crystal lattices is
week, and the inorganic stratiform compound greatly swells upon
contact with water. When share is applied under such condition, the
stratiform crystal lattices are easily cleaved to form a stable sol
in water. The bentnite and swellable synthetic mica have strongly
such tendency and are useful in the invention. Particularly, the
swellable synthetic mica is preferably used.
[0227] With respect to the shape of the inorganic stratiform
compound used in the invention, the thinner the thickness or the
larger the plain size as long as smoothness of coated surface and
transmission of actinic radiation are not damaged, the better from
the standpoint of control of diffusion. Therefore, an aspect ratio
of the inorganic stratiform compound is ordinarily 20 or more,
preferably 100 or more, particularly preferably 200 or more. The
aspect ratio is a ratio of thickness to major axis of particle and
can be determined, for example, from a projection drawing of
particle by a microphotography. The larger the aspect ratio, the
greater the effect obtained.
[0228] As for the particle size of the inorganic stratiform
compound used in the invention, an average major axis is ordinarily
from 0.3 to 20 .mu.m, preferably from 0.5 to 10 .mu.m, particularly
preferably from 1 to 5 .mu.m. An average thickness of the particle
is ordinarily 0.1 .mu.m or less, preferably 0.05 .mu.m or less,
particularly preferably 0.01 .mu.m or less. For example, in the
swellable synthetic mica that is the representative compound of the
inorganic stratiform compounds, thickness is approximately from 1
to 50 nm and plain size is approximately from 1 to 20 .mu.m.
[0229] When such an inorganic stratiform compound particle having a
large aspect ratio is incorporated into the protective layer,
strength of coated layer increases and penetration of oxygen or
moisture can be effectively inhibited so that the protective layer
can be prevented from deterioration due to deformation, and even
when the lithographic printing plate precursor is preserved for a
long period of time under a high humidity condition, it is
prevented from decrease in the image-forming property thereof due
to the change of humidity and exhibits excellent preservation
stability.
[0230] The content of the inorganic stratiform compound in the
protective layer is preferably from 5/1 to 1/00 in terms of weight
ratio to the amount of binder used in the protective layer. When a
plurality of inorganic stratiform compounds is used in combination,
it is also preferred that the total amount of the inorganic
stratiform compounds fulfills the above-described weight ratio.
[0231] An example of common dispersing method for the inorganic
stratiform compound used in the protective layer is described
below. Specifically, from 5 to 10 parts by weight of a swellable
stratiform compound that is exemplified as a preferred inorganic
stratiform compound is added to 100 parts by weight of water to
adapt the compound to water and to be swollen, followed by
dispersing using a dispersing machine. The dispersing machine used
include, for example, a variety of mills conducting dispersion by
directly applying mechanical power, a high-speed agitation type
dispersing machine providing a large shear force and a dispersion
machine providing ultrasonic energy of high intensity. Specific
examples thereof include a ball mill, a sand grinder mill, a visco
mill, a colloid mill, a homogenizer, a dissolver, a polytron, a
homomixer, a homoblender, a keddy mill, a jet agitor, a capillary
type emulsifying device, a liquid siren, an electromagnetic strain
type ultrasonic generator and an emulsifying device having a Polman
whistle. A dispersion containing from 5 to 10% by weight of the
inorganic stratiform compound thus prepared is highly viscous or
gelled and exhibits extremely good preservation stability. In the
formation of a coating solution for protective layer using the
dispersion, it is preferred that the dispersion is diluted with
water, sufficiently stirred and then mixed with a binder
solution.
[0232] To the coating solution for protective layer can be added
known additives, for example, a surfactant for improving coating
property or a water-soluble plasticizer for improving physical
property of coated layer in addition to the inorganic stratiform
compound. Examples of the water-soluble plasticizer include
propionamide, cyclohexanediol, glycerin or sorbitol. Also, a
water-soluble (meth)acrylic polymer can be added. Further, to the
coating solution may be added known additives for increasing
adhesion property to the image-recording layer or for improving
preservation stability of the coating solution.
[0233] The coating solution for protective layer thus-prepared is
coated on the image-recording layer and then dried to form a
protective layer. The coating solvent may be appropriately selected
in view of the binder used, and when a water-soluble polymer is
used, distilled water or purified water is preferably used as the
solvent. A coating method of the protective layer is not
particularly limited, and known methods, for example, methods
described in U.S. Pat. No. 3,458,311 and JP-B-55-49729 can be
utilized. Specific examples of the coating method for the
protective layer include a blade coating method, an air knife
coating method, a gravure coating method, a roll coating method, a
spray coating method, a dip coating method and a bar coating
method.
[0234] The coating amount of the protective layer is preferably in
a range of 0.05 to 10 g/m.sup.2 in terms of the coating amount
after drying. When the protective layer contains the inorganic
stratiform compound, it is more preferably in a range of 0.1 to 0.5
g/m.sup.2, and when the protective layer does not contain the
inorganic stratiform compound, it is more preferably in a range of
0.5 to 5 g/m.sup.2.
(Undercoat Layer)
[0235] In the lithographic printing plate precursor according to
the invention, an undercoat layer may be provided between the
image-recording layer and the support, if desired. The undercoat
layer has the effect of strengthening the adhesion property between
the support and the image-recording layer in the exposed area and
the effect of facilitating separation of the image-recording layer
from the support in the unexposed area, thereby improving the
developing property.
[0236] As the compound for the undercoat layer, specifically, a
silane coupling agent having an addition-polymerizable ethylenic
double bond reactive group described in JP-A-10-282679 and a
phosphorus compound having an ethylenic double bond reactive group
described in JP-A-2-304441 are preferably exemplified.
[0237] In the undercoat layer, known resins having a hydrophilic
group can also be used. Specific examples of the resin include gum
arabic, casein, gelatin, a starch derivative, carboxy methyl
cellulose and a sodium salt thereof, cellulose acetate, sodium
alginate, vinyl acetate-maleic acid copolymer, styrene-maleic acid
copolymer, polyacrylic acid and a salt thereof, polymethacrylic
acid and a salt thereof, a homopolymer or copolymer of hydroxyethyl
methacrylate, a homopolymer or copolymer of hydroxyethyl acrylate,
a homopolymer or copolymer of hydroxypropyl methacrylate, a
homopolymer or copolymer of hydroxypropyl acrylate, a homopolymer
or copolymer of hydroxybutyl methacrylate, a homopolymer or
copolymer of hydroxybutyl acrylate, a polyethylene glycol, a
hydroxypropylene polymer, a polyvinyl alcohol, a hydrolyzed
polyvinyl acetate having a hydrolysis degree of 60% by mole or
more, preferably 80% by mole or more, polyvinyl formal, polyvinyl
butyral, polyvinyl pyrrolidone, a homopolymer or copolymer of
acrylamide, a homopolymer or polymer of methacrylamide, a
homopolymer or copolymer of N-methylolacrylamide, polyvinyl
pyrrolidone, an alcohol-soluble nylon, a polyether of
2,2-bis-(4-hydroxyphenyl)propane and epichlorohydrin.
[0238] The polymer compound for use in the undercoat layer
preferably has adsorptivity to the surface of support. Whether the
adsorptivity to the surface of support is present or not can be
judged, for example, by the following method.
[0239] Specifically, a test compound is dissolved in a solvent in
which the test compound is easily soluble to prepare a coating
solution, and the coating solution is coated and dried on a support
so as to have the coating amount after drying of 30 mg/m.sup.2.
After thoroughly washing the support coated with the test compound
using the solvent in which the test compound is easily soluble, the
residual amount of the test compound that has not been removed by
the washing is measured to calculate the adsorption amount to the
support. For measurement of the residual amount, the amount of the
residual test compound may be directly determined, or it may be
calculated from the amount of the test compound dissolved in the
washing solution. The determination for the compound can be
performed, for example, by fluorescent X-ray measurement,
reflection spectral absorbance measurement or liquid chromatography
measurement. The compound having the adsorptivity to support means
a compound that remains by 1 mg/m.sup.2 or more even after
conducting the washing treatment described above.
[0240] Impartation of the adsorptivity to the surface of support to
the polymer compound can be performed by introduction of the
adsorbing group into the polymer compound. The adsorbing group to
the surface of support is a functional group capable of forming a
chemical bond (for example, an ionic bond, a hydrogen bond, a
coordinate bond or a bond with intermolecular force) with a
substance (for example, metal or metal oxide) or a functional group
(for example, a hydroxy group) present on the surface of support.
The adsorbing group is preferably an acid group or a cationic
group.
[0241] The acid group preferably has an acid dissociation constant
(pKa) of 7 or less. Examples of the acid group include a phenolic
hydroxy group, a carboxyl group, --SO.sub.3H, --OSO.sub.3H,
--PO.sub.3H.sub.2, --OPO.sub.3H.sub.2, --CONHSO.sub.2--,
--SO.sub.2NHSO.sub.2-- and --COCH.sub.2COCH.sub.3. Among them, a
phosphoric acid group (--OPO.sub.3H.sub.2 or --PO.sub.3H.sub.2) is
particularly preferred. The acid group may be the form of a metal
salt.
[0242] The cationic group is preferably an onium group. Examples of
the onium group include an ammonium group, a phosphonium group, an
arsonium group, a stibonium group, an oxonium group, a sulfonium
group, a selenonium group, a stannonium group and iodonium group.
Among them, the ammonium group, phosphonium group and sulfonium
group are preferred, the ammonium group and phosphonium group are
more preferred, and the ammonium group is most preferred.
[0243] In order to introduce the adsorbing group into the polymer
compound, a monomer having an adsorbing group is used. Preferable
examples of the monomer having the adsorbing group include
compounds represented by the following formula (VII) or (VIII):
##STR00359##
[0244] In formulae (VII) and (VIII), R.sup.1, R.sup.2 and R.sup.3
each independently represents a hydrogen atom, a halogen atom or an
alkyl group having from 1 to 6 carbon atoms. R.sup.1 and R.sup.2
and R.sup.3 each independently represents preferably a hydrogen
atom or an alkyl group having from 1 to 6 carbon atoms, more
preferably a hydrogen atom or an alkyl group having from 1 to 3
carbon atoms, and most preferably a hydrogen atom or a methyl
group. It is particularly preferred that R.sup.2 and R.sup.3 each
represents a hydrogen atom.
[0245] X represents an oxygen atom (--O--) or imino group (--NH--).
Preferably, X represents an oxygen atom.
[0246] L represents a divalent connecting group. It is preferred
that L represents a divalent aliphatic group (for example, an
alkylene group, a substituted alkylene group, an alkenylene group,
a substituted alkenylene group, an alkinylene group or a
substituted alkinylene group), a divalent aromatic group (for
example, an arylene group or a substituted arylene group), a
divalent heterocyclic group or a combination of each of the groups
described above with an oxygen atom (--O--), a sulfur atom (--S--),
an imino group (--NH--), a substituted imino group (--NR--, wherein
R represents an aliphatic group, an aromatic group or a
heterocyclic group) or a carbonyl group (--CO--).
[0247] The aliphatic group may form a cyclic structure or a
branched structure. The number of carbon atoms of the aliphatic
group is preferably from 1 to 20, more preferably from 1 to 15,
most preferably from 1 to 10. It is preferred that the aliphatic
group is a saturated aliphatic group rather than an unsaturated
aliphatic group. The aliphatic group may have a substituent.
Examples of the substituent include a halogen atom, a hydroxy
group, an aromatic group and a heterocyclic group.
[0248] The number of carbon atoms of the aromatic group is
preferably from 6 to 20, more preferably from 6 to 15, most
preferably from 6 to 10. The aromatic group may have a substituent.
Examples of the substituent include a halogen atom, a hydroxy
group, an aliphatic group, an aromatic group and a heterocyclic
group.
[0249] It is preferred that the heterocyclic group has a 5-membered
or 6-membered ring as the hetero ring. Other heterocyclic ring, an
aliphatic ring or an aromatic ring may be condensed to the
heterocyclic ring. The heterocyclic group may have a substituent.
Examples of the substituent include a halogen atom, a hydroxy
group, an oxo group (.dbd.O), a thioxo group (.dbd.S), an imino
group (.dbd.NH), a substituted imino group (.dbd.N--R, where R
represents an aliphatic group, an aromatic group or a heterocyclic
group), an aliphatic group, an aromatic group and a heterocyclic
group.
[0250] It is preferred that L represents a divalent connecting
group containing a plurality of polyoxyalkylene structures. It is
more preferred that the polyoxyalkylene structure is a
polyoxyethylene structure. Specifically, it is preferred that L
contains --(OCH.sub.2CH.sub.2).sub.n-- (n is an integer of 2 or
more).
[0251] Z represents a functional group adsorbing to the hydrophilic
surface of support. The adsorptive functional group is the same as
that described above.
[0252] Y represents a carbon atom or a nitrogen atom. In the case
where Y is a nitrogen atom and L is connected to Y to form a
quaternary pyridinium group, Z is not mandatory, because the
quaternary pyridinium group itself exhibits the adsorptivity.
[0253] Representative examples of the monomer represented by
formula (VII) or (VIII) are set forth below.
##STR00360## ##STR00361##
[0254] It is preferred that the polymer compound for use in the
undercoat layer further has a hydrophilic group. Examples of the
hydrophilic group includes a hydroxy group, a carboxyl group, a
carboxylate group, a hydroxyethyl group, a polyoxyethyl group, a
hydroxypropyl group, a polyoxypropyl group, an amino group, an
aminoethyl group, an aminopropyl group, an ammonium group, an amido
group, a carboxymethyl group, a sulfonic acid group and a
phosphoric acid group.
[0255] In the case of using the binder polymer containing a
cationic group in its side chain in the image-recording layer
according to the invention, as the hydrophilic group of the polymer
compound for undercoat layer which interacts with the cationic
group, an anionic group, for example, a carboxyl group, a
carboxylate group, a sulfonic acid group or a phosphoric acid group
is preferable.
[0256] It is preferred that the polymer rcompound for undercoat
layer used in the invention further has a crosslinkable group. The
crosslinkable group acts to improve the adhesion property to the
image area. In order to impart the crosslinking property to the
polymer compound for undercoat layer, introduction of a
crosslinkable functional group, for example, an ethylenically
unsaturated bond into the side chain of the polymer or introduction
by formation of a salt structure between a polar substituent of the
polymer compound and a compound containing a substituent having a
counter charge to the polar substituent of the polymer compound and
an ethylenically unsaturated bond is used.
[0257] Examples of the monomer having the ethylenically unsaturated
bond in the molecule thereof include a monomer of an ester or amide
of acrylic acid or methacrylic acid, wherein the ester or amide
residue (R in --COOR or --CONHR) has the ethylenically unsaturated
bond.
[0258] Examples of the residue (R described above) having an
ethylenically unsaturated bond include
--(CH.sub.2).sub.nCR.sub.1.dbd.CR.sub.2R.sub.3,
--(CH.sub.2O).sub.nCH.sub.2CR.sub.1.dbd.CR.sub.2R.sub.3,
--(CH.sub.2CH.sub.2O).sub.nCH.sub.2CR.sub.1.dbd.CR.sub.2R.sub.3,
--(CH.sub.2).sub.nNH--CO--O--CH.sub.2CR.sub.1.dbd.CR.sub.2R.sub.3,
--(CH.sub.2).sub.n--O--CO--CR.sub.1.dbd.CR.sub.2R.sub.3 and
--(CH.sub.2CH.sub.2O).sub.2--X (wherein R.sub.1 to R.sub.3 each
represents a hydrogen atom, a halogen atom or an alkyl group having
from 1 to 20 carbon atoms, an aryl group, alkoxy group or aryloxy
group, or R.sub.1 and R.sub.2 or R.sub.1 and R.sub.3 may be
combined with each other to form a ring. n represents an integer of
1 to 10. X represents a dicyclopentadienyl residue).
[0259] Specific examples of the ester residue include
--CH.sub.2CH.dbd.CH.sub.2,
--CH.sub.2CH.sub.2O--CH.sub.2CH.dbd.CH.sub.2,
--CH.sub.2C(CH.sub.3).dbd.CH.sub.2,
--CH.sub.2CH.dbd.CH--C.sub.6H.sub.5,
--CH.sub.2CH.sub.2OCOCH.dbd.CH--C.sub.6H.sub.5,
--CH.sub.2CH.sub.2--NHCOO--CH.sub.2CH.dbd.CH.sub.2 and
--CH.sub.2CH.sub.2O--X (wherein X represents a dicyclopentadienyl
residue).
[0260] Specific examples of the amide residue include
--CH.sub.2CH.dbd.CH.sub.2, --CH.sub.2CH.sub.2O--Y (wherein Y
represents a cyclohexene residue) and
--CH.sub.2CH.sub.2OCO--CH.dbd.CH.sub.2.
[0261] The content of the crosslinkable group in the polymer
compound for undercoat layer (content of the radical polymerizable
unsaturated double bond determined by iodine titration) is
preferably from 0.1 to 10.0 mmol, more preferably from 1.0 to 7.0
mmol, most preferably from 2.0 to 5.5 mmol, based on 1 g of the
polymer compound. In the range described above, preferable
compatibility between the sensitivity and stain resistance and good
preservation stability can be achieved.
[0262] As the polymer compound for undercoat layer, a polymer
including a monomer unit having an adsorbing group and a monomer
unit having a hydrophilic group is preferable and a polymer
including a monomer unit having an adsorbing group, a monomer unit
having a hydrophilic group and a monomer unit having a
crosslinkable group is particularly preferable.
[0263] Specific examples of the polymer compound for undercoat
layer are set forth below, but the invention should not be
construed as being limited thereto.
##STR00362## ##STR00363## ##STR00364## ##STR00365## ##STR00366##
##STR00367##
[0264] Further, a copolymer including a repeating unit having an
ethylenically unsaturated bond or the like described in
JP-A-2005-125749 is also preferably used.
[0265] The weight average molecular weight of the polymer compound
for undercoat layer is preferably 5,000 or more, more preferably
from 10,000 to 300,000. The number average molecular weight of the
polymer compound is preferably 1,000 or more, more preferably from
2,000 to 250,000. The polydispersity (weight average molecular
weight/number average molecular weight) thereof is preferably from
1.1 to 10.
[0266] The polymer compound for undercoat layer may be any of a
random polymer, a block polymer, a graft polymer and the like, and
is preferably a random polymer.
[0267] The polymer compounds for undercoat layer may be used
individually or in a mixture of two or more thereof.
[0268] The coating amount (solid content) of the undercoat layer is
preferably from 0.1 to 100 mg/m.sup.2, more preferably from 1 to 30
mg/m.sup.2.
(Backcoat Layer)
[0269] After applying the surface treatment to the support or
forming an undercoat layer on the support, a backcoat layer can be
provided on the back surface of the support, if desired.
[0270] The backcoat layer preferably includes, for example, a
coating layer comprising an organic polymer compound described in
JP-A-5-45885 and a coating layer comprising a metal oxide obtained
by hydrolysis and polycondensation of an organic metal compound or
an inorganic metal compound described in JP-A-6-34174. Among them,
use of an alkoxy compound of silicon, for example,
Si(OCH.sub.3).sub.4, Si(OC.sub.2H.sub.5).sub.4,
Si(OC.sub.3H.sub.7).sub.4 or Si(OC.sub.4H.sub.9).sub.4 is preferred
since the starting material is inexpensive and easily
available.
[Processing Method of Lithographic Printing Plate Precursor]
[0271] According to the processing method of a lithographic
printing plate precursor of the invention, the lithographic
printing plate precursor according to the invention is exposed
imagewise by a light source of an appropriate wavelength and then
subjected to development processing with an aqueous solution having
pH of 2 to 10 and containing an amphoteric surfactant and an
anionic surfactant selected from an anionic surfactant having an
aliphatic chain and a total number of carbon atoms included in the
aliphatic chain of 6 or more and an anionic surfactant having an
aromatic ring and a total number of carbon atoms of 12 or more,
wherein the content of the anionic surfactant is from 0.1 to 3.3%
by weight of the aqueous solution, thereby removing the
image-recording layer of the non-image area to form an image on the
support.
[0272] Further, in a plate-making process to prepare a lithographic
printing plate from the lithographic printing plate precursor
according to the invention, the entire surface of the lithographic
printing plate precursor may be heated, if desired, before or
during the exposure or between the exposure and the development. By
the heating, the image-forming reaction in the image-recording
layer is accelerated and advantages, for example, improvement in
the sensitivity and printing durability and stabilization of the
sensitivity are achieved. For the purpose of increasing the image
strength and printing durability, it is also effective to perform
entire after-heating or entire exposure of the image after the
development. Ordinarily, the heating before the development is
preferably performed under a mild condition of 150.degree. C. or
lower. When the temperature is too high, a problem may arise in
that undesirable fog occurs in the non-image area. On the other
hand, the heating after the development can be performed using a
very strong condition. Ordinarily, the heat treatment is carried
out in a temperature range of 200 to 500.degree. C. When the
temperature is too low, a sufficient effect of strengthening the
image may not be obtained, whereas when it is excessively high,
problems of deterioration of the support and thermal decomposition
of the image area may occur.
[0273] The plate-making process is described in more detail
below.
[0274] In the invention, although the development processing can be
carried out just after the exposure step, the heat treatment step
may intervene between the exposure step and the development step as
described above. The heat treatment is effective for increasing the
printing durability and improving uniformity of the image curing
degree in the entire surface of printing plate precursor. The
conditions of the heat treatment can be appropriately determined in
a range for providing such effects. Examples of the heating means
include a conventional convection oven, an IR irradiation
apparatus, an IR laser, a microwave apparatus or a Wisconsin oven.
For instance, the heat treatment can be conducted by maintaining
the printing plate precursor at a plate surface temperature ranging
from 70 to 150.degree. C. for a period of one second to 5 minutes,
preferably at 80 to 140.degree. C. for 5 seconds to one minute,
more preferably at 90 to 130.degree. C. for 10 to 30 seconds. In
the above-described range, the effects described above are
efficiently achieved and an adverse affect, for example, change in
shape of the printing plate precursor due to the heat can be
preferably avoided.
[0275] According to the invention, the development processing step
is conducted after the exposure step, preferably after the exposure
step and the heat treatment step to prepare a lithographic printing
plate. It is preferable that a plate setter used in the exposure
step, a heat treatment means used in the heat treatment step and a
development apparatus used in the development processing step are
connected with each other and the lithographic printing plate
precursor is subjected to automatically continuous processing.
Specifically, a plate-making line wherein the plate setter and the
development apparatus are connected with each other by transport
means, for example, a conveyer is illustrated. Also, the heat
treatment means may be placed between the plate setter and the
development apparatus or the heat treatment means and the
development apparatus may constitute a unit apparatus.
[0276] In case where the lithographic printing plate precursor used
is apt to be influenced by surrounding light under a working
environment, it is preferable that the plate-making line is blinded
by a filter, a cover or the like.
[0277] After the image formation as described above, the entire
surface of lithographic printing plate may be exposed to active
ray, for example, ultraviolet light to accelerate curing of the
image area. As a light source for the entire surface exposure, for
example, a carbon arc lamp, a mercury lamp, a gallium lamp, a metal
halide lamp, a xenon lamp, a tungsten lamp or various laser beams
are exemplified. In order to obtain sufficient printing durability,
the amount of the entire surface exposure is preferably 10
mJ/cm.sup.2 or more, more preferably 100 mJ/cm.sup.2 or more.
[0278] Heating may be performed at the same time with the entire
surface exposure. By performing the heating, further improvement in
the printing durability is recognized. Examples of the heating
means include a conventional convection oven, an IR irradiation
apparatus, an IR laser, a microwave apparatus or a Wisconsin oven.
The plate surface temperature at the heating is preferably from 30
to 150.degree. C., more preferably from 35 to 130.degree. C., still
more preferably from 40 to 120.degree. C.
[0279] In advance of the above-described development processing,
the lithographic printing plate precursor is imagewise exposed
through a transparent original having a line image, a halftone dot
image or the like, or imagewise exposed, for example, by scanning
of laser beam based on digital data.
[0280] The desirable wavelength of the light source is from 350 to
450 nm, and specifically, an InGaN semiconductor laser is
preferably used. The exposure mechanism may be any of an internal
drum system, an external drum system and a flat bed system.
[0281] Other examples of the exposure light source which can be
used in the invention include an ultra-high pressure mercury lamp,
a high pressure mercury lamp, a medium pressure mercury lamp, a low
pressure mercury lamp, a chemical lamp, a carbon arc lamp, a xenon
lamp, a metal halide lamp, various visible or ultraviolet laser
lamps, a fluorescent lamp, a tungsten lamp and sunlight.
[0282] As for the available laser light source of 350 to 450 nm,
the followings can be used.
[0283] A gas laser, for example, Ar ion laser (364 nm, 351 nm, 10
mW to 1 W), Kr ion laser (356 nm, 351 nm, 10 mW to 1 W) and He--Cd
laser (441 nm, 325 nm, 1 mW to 100 mW); a solid laser, for example,
a combination of Nd:YAG (YVO.sub.4) with SHG crystals.times.twice
(355 nm, mW to 1 W) and a combination of Cr:LiSAF with SHG crystal
(430 nm, 10 mW); a semiconductor laser system, for example, a
KNbO.sub.3 ring resonator (430 nm, 30 mW), a combination of a
waveguide-type wavelength conversion element with an AlGaAs or
InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), a
combination of a waveguide-type wavelength conversion element with
an AlGaInP or AlGaAs semiconductor (300 nm to 350 nm, 5 mW to 100
mW), and AlGaInN (350 nm to 450 nm, 5 mW to 30 mW); a pulse laser,
for example, N.sub.2 laser (337 nm, pulse 0.1 to 10 mJ) and XeF
(351 nm, pulse 10 to 250 mJ) can be used. Among the light sources,
the AlGaInN semiconductor laser (commercially available InGaN
semiconductor laser, 400 to 410 nm, 5 to 30 mW) is particularly
preferable in view of the wavelength characteristics and cost.
[0284] The laser used in the invention also includes an infrared
laser. The infrared laser for use in the invention is not
particularly restricted and, for example, a solid laser or
semiconductor laser emitting an infrared ray having a wavelength of
760 to 1,200 nm is preferably exemplified. The output of the
infrared laser is preferably 100 mW or more. Further, in order to
shorten the exposure time, it is preferred to use a multibeam laser
device.
[0285] The exposure time per pixel is preferably within 20
microseconds, and the irradiation energy is preferably from 10 to
300 mJ/cm.sup.2.
[0286] As for the exposure apparatus for the lithographic printing
plate precursor of scanning exposure system, the exposure mechanism
includes an internal drum system, an external drum system and a
flat bed system. As the light source, among the light sources
described above, those capable of conducting continuous oscillation
can be preferably utilized. In practice, the exposure apparatuses
described below are particularly preferable in view of the
relationship between the sensitivity of lithographic printing plate
precursor (photosensitive material) and the time for
plate-making.
[0287] A single beam to triple beam exposure apparatus of internal
drum system, using one or more gas or solid laser light sources so
as to provide a semiconductor laser having a total output of 20 mW
or more
[0288] A multi-beam (from 1 to 10 beams) exposure apparatus of flat
bed system, using one or more semiconductor, gas or solid lasers so
as to provide a total output of 20 mW or more
[0289] A multi-beam (from 1 to 9 beams) exposure apparatus of
external drum system, using one or more semiconductor, gas or solid
lasers so as to provide a total output of 20 mW or more
[0290] A multi-beam (10 or more beams) exposure apparatus of
external drum system, using one or more semiconductor or solid
lasers so as to provide a total output of 20 mW or more
[0291] In the laser direct drawing-type lithographic printing plate
precursor, the following equation (eq 1) is ordinarily established
among the sensitivity X (J/cm.sup.2) of photosensitive material,
the exposure area S (cm.sup.2) of photosensitive material, the
power q (W) of one laser light source, the number n of lasers and
the total exposure time t (s):
XS=nqt (eq 1)
i) In the Case of the Internal Drum (Single Beam) System
[0292] The following equation (eq 2) is ordinarily established
among the laser revolution number f (radian/s), the sub-scanning
length Lx (cm) of photosensitive material, the resolution Z
(dot/cm) and the total exposure time t (s):
fZt=Lx (eq 2)
ii) In the Case of the External Drum (Multi-Beam) System
[0293] The following equation (eq 3) is ordinarily established
among the drum revolution number F (radian/s), the sub-scanning
length Lx (cm) of photosensitive material, the resolution Z
(dot/cm), the total exposure time t (s) and the number (n) of
beams:
FZnt=Lx (eq 3)
iii) In the Case of the Flat Bed (Multi-Beam) System
[0294] The following equation (eq 4) is ordinarily established
among the revolution number H (radian/s) of polygon mirror, the
sub-scanning length Lx (cm) of photosensitive material, the
resolution Z (dot/cm), the total exposure time t (s) and the number
(n) of beams:
HZnt=Lx (eq 4)
[0295] When the resolution (2,560 dpi) required for a practical
printing plate, the plate size (A1/B1, sub-scanning length: 42
inch), the exposure condition of about 20 sheets/hour and the
photosensitive characteristics (photosensitive wavelength,
sensitivity: about 0.1 mJ/cm.sup.2) of the lithographic printing
plate precursor according to the invention are substituted for the
above equations, it can be understood that the lithographic
printing plate precursor according to the invention is preferably
combined with a multi-beam exposure system using a laser having a
total output of 20 mW or more, and on taking account of
operability, cost and the like, it is most preferably combined with
an external drum system semiconductor laser multi-beam (10 or more
beams) exposure apparatus.
[Development Processing Solution]
[0296] The development processing solution (hereinafter, also
simply referred to as a "processing solution" or a "developer") for
use in the processing method of a lithographic printing plate
precursor according to the invention is characterized by being an
aqueous solution having pH of 2 to 10 and containing an amphoteric
surfactant and an anionic surfactant selected from an anionic
surfactant having an aliphatic chain and a total number of carbon
atoms included in the aliphatic chain of 6 or more and an anionic
surfactant having an aromatic ring and a total number of carbon
atoms of 12 or more, wherein the content of the anionic surfactant
is from 0.1 to 3.3% by weight of the aqueous solution.
[0297] The amphoteric surfactant for use in the developer according
to the invention is a compound having an anionic site and a
cationic site in the same molecule, as well known in the field of
surfactant, and includes amphoteric surfactants of amino acid type,
betaine type and amineoxide type. As the amphoteric surfactant for
use in the developer according to the invention, the compound
represented by formula <1> shown below and the compound
represented by formula <2> shown below are preferable.
##STR00368##
[0298] In formula <1>, R8 represents an alkyl group, R9 and
R10 each represents a hydrogen atom or an alkyl group, R11
represents an alkylene group, and A represents a carboxylate ion or
a sulfonate ion.
[0299] In formula <2>, R18, R19 and R20 each represents a
hydrogen atom or an alkyl group, provided that all of R18, R19 and
R20 are not hydrogen atoms at the same time.
[0300] In formula <1>, the alkyl group represented by R8, R9
or R10 or the alkylene group represented by R11 may be a straight
chain or branched structure and may contain a connecting group in
the chain thereof and a substituent. As the connecting group, a
connecting group containing a hetero atom, for example, an ester
bond, an amido bond or an ether bond is preferable. As the
substituent, for example, a hydroxy group, an ethyleneoxide group,
a phenyl group, an amido group or a halogen atom is preferable.
[0301] In the compound represented by formula <1>, as the
total number of carbon atoms increases, the hydrophobic portion
becomes large and dissolution of the compound in an aqueous
developer becomes difficult. In such a case, the dissolution is
improved by adding a dissolution auxiliary agent, for example, an
organic solvent such as an alcohol. However, when the total number
of carbon atoms excessively increases, the surfactant can not be
dissolved in a proper mixing range in some cases. Therefore, the
total number of carbon atoms included in R8 to R11 is preferably
from 8 to 25, more preferably from 11 to 21.
[0302] In formula <2>, the alkyl group represented by R18,
R19 or R20 may be a straight chain or branched structure and may
contain a connecting group in the chain thereof and a substituent.
As the connecting group, a connecting group containing a hetero
atom, for example, an ester bond, an amido bond or an ether bond is
preferable. As the substituent, for example, a hydroxy group, an
ethyleneoxide group, a phenyl group, an amido group or a halogen
atom is preferable.
[0303] In the compound represented by formula <2>, as the
total number of carbon atoms increases, the hydrophobic portion
becomes large and dissolution of the compound in an aqueous
developer becomes difficult. In such a case, the dissolution is
improved by adding a dissolution auxiliary agent, for example, an
organic solvent such as an alcohol. However, when the total number
of carbon atoms excessively increases, the surfactant can not be
dissolved in a proper mixing range in some cases. Therefore, the
total number of carbon atoms included in R18 to R20 is preferably
from 8 to 22, more preferably from 10 to 20.
[0304] The total number of carbon atoms in the amphoteric
surfactant is influenced by a material, especially, a binder, used
in the image-recording layer. When a binder having high
hydrophilicity is used, it tends to be preferable that the total
number of carbon atoms is relatively small. On the other hand, when
a binder having low hydrophilicity is used, it tends to be
preferable that the total number of carbon atoms is large.
[0305] Specific preferable examples of the amphoteric surfactant
for use in the developer are set forth below, but the invention
should not be construed as being limited thereto.
##STR00369## ##STR00370##
[0306] The amount of the amphoteric surfactant added to the
developer is not particularly restricted and preferably from 1 to
50% by weight, particularly preferably from 3 to 30% by weight,
most preferably from 5 to 15% by weight.
[0307] The anionic surfactant for use in the developer according to
the invention is an anionic surfactant selected from an anionic
surfactant having an aliphatic chain and a total number of carbon
atoms included in the aliphatic chain of 6 or more and an anionic
surfactant having an aromatic ring and a total number of carbon
atoms of 12 or more.
[0308] As such an anionic surfactant, an appropriate compound may
be used. Of the anionic surfactants having an aliphatic chain and a
total number of carbon atoms included in the aliphatic chain of 6
or more, those having a total number of carbon atoms included in
the aliphatic chain of 8 or more are more preferable. Of the
anionic surfactant having an aromatic ring and a total number of
carbon atoms of 12 or more, those having a total number of carbon
atoms of 14 or more are more preferable.
[0309] As the anionic surfactant having an aliphatic chain and a
total number of carbon atoms included in the aliphatic chain of 6
or more, anionic surfactants selected from compounds represented by
formula <4> or <5> shown below are preferable.
C.sub.1H.sub.2l+1-X <4>
C.sub.n-mH.sub.2(n-m)+1OC.sub.mH.sub.2m--X
[0310] In formulae <4> or <5>, l, n and m each
represents an integer satisfying 1.gtoreq.6, n.gtoreq.6 and
n.gtoreq.m.gtoreq.0, and X represents a sulfonate, a sulfuric
monoester salt, a carboxylate or a phosphate.
[0311] As the anionic surfactant having an aromatic ring and a
total number of carbon atoms of 12 or more, anionic surfactants
selected from compounds represented by formulae <6> to
<9> shown below are preferable.
##STR00371##
[0312] In formulae <6> and <7>, R.sub.1 to R.sub.10
each represents a hydrogen atom, an alkyl group or an alkyl group
containing an oxygen atom; l represents an integer of 1 to 3,
X.sub.1 and X.sub.2 each represents a sulfonate, a sulfuric
monoester salt, a carboxylate or a phosphate, and provided that a
total number of carbon atoms included in formula <6> or
<7> is 12 or more.
[0313] The alkyl group containing an oxygen atom represented by any
one of R.sub.1 to R.sub.10 in formulae <6> and <7>
include an alkyl group containing an oxygen atom at its terminal
and/or in its chain and a group represented by formula (A) shown
below.
--C.sub.mH.sub.2mOC.sub.n-mH.sub.2(n-m)+1 (A)
(wherein n and m each represents an integer, provided that
n.gtoreq.2, n.gtoreq.m.gtoreq.0)
[0314] The alkyl group or the alkyl chain in the alkyl group
containing an oxygen atom represented by any one of R.sub.1 to
R.sub.10 in formulae <6> and <7> may be a straight
chain or branched structure and may contain a substituent. As the
substituent, for example, a halogen atom, an ethyleneoxide group, a
phenyl group and an amido group are exemplified.
##STR00372##
[0315] In formulae <8> and <9>, R.sub.1 to R.sub.10
each represents a hydrogen atom or an alkyl group, l represents an
integer of 1 to 3, X.sub.1 and X.sub.2 each represents a sulfonate,
a sulfuric monoester salt, a carboxylate or a phosphate, Y.sub.1
and Y.sub.2 each represents --C.sub.nH.sub.2n--,
--C.sub.n-mH.sub.2(n-m)OC.sub.mH.sub.2m--,
--O--(CH.sub.2CH.sub.2O).sub.n--,
--O--(CH.sub.2CH.sub.2CH.sub.2O).sub.n-- or --CO--NH--, wherein n
and m each represents an integer, provided that n.gtoreq.1 and
n.gtoreq.m.gtoreq.0, and provided that a total number of carbon
atoms included in formula <8> or <9> is 12 or more.
[0316] The alkyl group represented by any one of R.sub.1 to
R.sub.10 in formulae <8> and <9> may be a straight
chain or branched structure and may contain a substituent. As the
substituent, for example, a halogen atom, an ethyleneoxide group, a
phenyl group and an amido group are exemplified.
[0317] Specific preferable examples of the anionic surfactant for
use in the developer are set forth below, but the invention should
not be construed as being limited thereto.
##STR00373## ##STR00374##
[0318] The amount of the anionic surfactant added to the developer
is not particularly restricted and suitably from 0.1 to 3.3% by
weight, preferably from 0.3 to 3% by weight, particularly
preferably from 0.5 to 1.5% by weight.
[0319] In the development processing solution according to the
invention, a ratio of the anionic surfactant to the amphoteric
surfactant is preferably from 0.1 to 50% by weight, more preferably
from 1.0 to 30% by weight, still more preferably from 3.0 to 20% by
weight.
[0320] It is also preferred that any of the amphoteric surfactant
and anionic surfactant for use in the development processing
solution according to the invention is not a polymer and the
molecular weight thereof is preferably from 50 to 5,000, more
preferably from 100 to 3,000, still more preferably from 120 to
1,000.
[0321] The development processing solution according to the
invention may contain a water-soluble polymer compound in addition
to the above-described specific surfactants so that an
oil-desensitization treatment can be simultaneously performed with
the development processing. Needless to say, the lithographic
printing plate precursor is developed with the solution containing
no water-soluble polymer compound and then subjected to the
oil-desensitization treatment with an aqueous solution containing
the water-soluble polymer compound.
[0322] The water-soluble polymer compound for use in the
development processing solution includes, for example, soybean
polysaccharide, modified starch, gum arabic, dextrin, a cellulose
derivative (for example, carboxymethyl cellulose, carboxyethyl
cellulose or methyl cellulose) or a modified product thereof,
pllulan, polyvinyl alcohol or a derivative thereof, polyvinyl
pyrrolidone, polyacrylamide, an acrylamide copolymer, a vinyl
methyl ether/maleic anhydride copolymer, a vinyl acetate/maleic
anhydride copolymer and a styrene/maleic anhydride copolymer.
[0323] As the soybean polysaccharide, those conventionally known
can be used. For example, as a commercial product, Soyafive (trade
name, produced by Fuji Oil Co., Ltd.) is available and various
grade products can be used. The soybean polysaccharide preferably
used has viscosity in a range of 10 to 100 mPa/sec in a 10% by
weight aqueous solution thereof.
[0324] As the modified starch, those represented by formula (III)
shown below are preferable. As starch for the modified starch
represented by formula (III), any starch, for example, of corn,
potato, tapioca, rice or wheat can be used. The modification of
starch can be performed by a method wherein starch is decomposed,
for example, with an acid or an enzyme to an extent that the number
of glucose residue per molecule is from 5 to 30 and then
oxypropylene is added thereto in an alkali.
##STR00375##
[0325] In formula (III), the etherification degree (substitution
degree) is in a range of 0.05 to 1.2 per glucose unit, n represents
an integer of 3 to 30, and m represents an integer of 1 to 3.
[0326] Of the water-soluble polymer compound, for example, soybean
polysaccharide, modified starch, gum arabic, dextrin, carboxymethyl
cellulose or polyvinyl alcohol is particularly preferable.
[0327] Two or more of the water-soluble polymer compounds may be
used in combination. The content of the water-soluble polymer
compound is preferably from 0.1 to 20% by weight, more preferably
from 0.5 to 10% by weight, in the processing solution.
[0328] The processing solution according to the invention may
contain a wetting agent, an antiseptic agent, a chelating agent, a
defoaming agent, an organic acid, an organic solvent, an inorganic
acid, an inorganic salt or the like, in addition to the above
components.
[0329] As the wetting agent, for example, ethylene glycol,
propylene glycol, triethylene glycol, butylene glycol, hexylene
glycol, diethylene glycol, dipropylene glycol, glycerin,
trimethylol propane or diglycerin is preferably used. The wetting
agents may be used individually or in combination of two or more
thereof. The wetting agent is ordinarily used in an amount of 0.1
to 5% by weight based on the total weight of the processing
solution.
[0330] As the antiseptic agent, for example, phenol or a derivative
thereof, formalin, an imidazole derivative, sodium dehydroacetate,
a 4-isothiazolin-3-one derivative, benzisothiazolin-3-one,
2-methyl-4-isothiazolin-3-one, a benzotriazole derivative, an
amidine guanidine derivative, a quaternary ammonium salt, a
pyridine derivative, a quinoline derivative, a guanidine
derivative, diazine, a triazole derivative, oxazole, an oxazine
derivative or a nitrobromoalcohol-based compound, e.g.,
2-bromo-2-nitropropane-1,3-diol, 1,1-dibromo-1-nitro-2-ethanol or
1,1-dibromo-1-nitro-2-propanol is preferably used.
[0331] The amount of the antiseptic agent added is an amount stably
exerts the effect to bacterium, molds, yeast or the like. Although
the amount of the antiseptic agent may be varied depending on the
kind of the bacterium, molds, yeast or the like, it is preferably
in a range of 0.01 to 4% by weight based on the processing solution
at the time of use. Also, it is preferred to use two or more kinds
of the antiseptic agents so as to exert the effect to various molds
and bacteria.
[0332] As the chelating agent, for example,
ethylenediaminetetraacetic acid, potassium salt thereof, sodium
salt thereof; diethylenetriaminepentaacetic acid, potassium salt
thereof, sodium salt thereof; triethylenetetraminehexaacetic acid,
potassium salt thereof, sodium salt thereof;
hydroxyethylethylenediaminetriacetic acid, potassium salt thereof,
sodium salt thereof; nitrilotriacetic acid, sodium salt thereof;
organic phosphonic acids, for example,
1-hydroxyethane-1,1-diphosphonic acid, potassium salt thereof,
sodium salt thereof, aminotri(methylenephosphonic acid), potassium
salt thereof, sodium salt thereof; and phosphonoalkanetricarboxylic
acids are illustrated. A salt of an organic amine is also
effectively used in place of the sodium salt or potassium salt in
the chelating agent.
[0333] The chelating agent is so selected that it is stably present
in the processing solution and does not impair the printing
property. The amount of the chelating agent added is preferably
from 0.001 to 1.0% by weight based on the processing solution at
the time of use.
[0334] As the defoaming agent, for example, a conventional
silicone-based self-emulsifying type or emulsifying type defoaming
agent, or a nonionic surfactant having HLB of 5 or less is used.
The silicone defoaming agent is preferably used. Any of emulsifying
dispersing type and solubilizing type can be used.
[0335] Since the processing solution according to the invention
contains the specific anionic surfactant as described above and has
a tendency of foam, it is preferred to use the defoaming agent.
[0336] The amount of the defoaming agent is preferably in a range
of 0.001 to 1.0% by weight based on the processing solution at the
time of use.
[0337] As the organic acid, for example, citric acid, acetic acid,
oxalic acid, malonic acid, salicylic acid, caprylic acid, tartaric
acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic
acid, xylenesulfonic acid, phytic acid or an organic phosphonic
acid is illustrated. The organic acid can also be used in the form
of an alkali metal salt or an ammonium salt. The amount of the
organic acid added is preferably from 0.01 to 0.5% by weight based
on the total weight of the processing solution.
[0338] The organic solvent include, for example, an aliphatic
hydrocarbon (e.g., hexane, heptane, Isopar E, Isopar H, Isopar G
(produced by Esso Chemical Co., Ltd.), gasoline or kerosene), an
aromatic hydrocarbon (e.g., toluene or xylene), a halogenated
hydrocarbon (methylene dichloride, ethylene dichloride, trichlene
or monochlorobenzene) and a polar solvent.
[0339] Examples of the polar solvent include an alcohol (e.g.,
methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene
glycol monomethyl ether, 2-ethyoxyethanol, diethylene glycol
monoethyl ether, diethylene glycol monohexyl ether, triethylene
glycol monomethyl ether, propylene glycol monoethyl ether,
propylene glycol monomethyl ether, polyethylene glycol monomethyl
ether, polypropylene glycol, tetraethylene glycol, ethylene glycol
monobutyl ether, ethylene glycol monobenzyl ether, ethylene glycol
monophenyl ether, methyl phenyl carbinol, n-amyl alcohol or
methylamyl alcohol), a ketone (e.g., acetone, methyl ethyl ketone,
ethyl butyl ketone, methyl isobutyl ketone or cyclohexanone), an
ester (e.g., ethyl acetate, propyl acetate, butyl acetate, amyl
acetate, benzyl acetate, methyl lactate, butyl lactate, ethylene
glycol monobutyl acetate, polyethylene glycol monomethyl ether
acetate, diethylene glycol acetate, diethyl phthalate or butyl
levulinate) and others (e.g., triethyl phosphate, tricresyl
phosphate, N-phenylethanolamine or N-phenyldiethanolamine).
[0340] Further, when the organic solvent is insoluble in water, it
may be employed by being solubilized in water using a surfactant or
the like. In the case where the developer contains the organic
solvent, the concentration of the organic solvent is desirably less
than 40% by weight in view of safety and inflammability.
[0341] As the inorganic acid or inorganic salt, for example,
phosphoric acid, methaphosphoric acid, ammonium primary phosphate,
ammonium secondary phosphate, sodium primary phosphate, sodium
secondary phosphate, potassium primary phosphate, potassium
secondary phosphate, sodium tripolyphosphate, potassium
pyrophosphate, sodium hexamethaphosphate, magnesium nitrate, sodium
nitrate, potassium nitrate, ammonium nitrate, sodium sulfate,
potassium sulfate, ammonium sulfate, sodium sulfite, ammonium
sulfite, sodium hydrogen sulfate or nickel sulfate is illustrated.
The amount of the inorganic acid or inorganic salt added is
preferably from 0.01 to 0.5% by weight based on the total weight of
the processing solution.
[0342] The processing solution for use in the invention can be
obtained by dissolving or dispersing the above-described components
according to need in water. The solid concentration of the
processing solution is preferably from 2 to 25% by weight. It is
also possible to prepare a concentrated solution and to dilute the
concentrated solution with water at the time of use.
[0343] From the standpoint of the developing property, the pH of
the processing solution for use in the invention is suitably from
2.0 to 10.0, preferably from 3.0 to 7.0, more preferably from 3.5
to 6.5, particularly preferably from 3.5 to 5.5.
[0344] In order to bring the processing solution into contact with
the lithographic printing plate precursor, a treatment with hand,
an immersion treatment and a treatment by a machine, for example, a
horizontal transportation processing and the like are
exemplified.
[0345] The exposed lithographic printing plate precursor is heated
in a pre-heating unit provided in advance of the development. It is
preferred that the lithographic printing plate precursor is
introduced into the pre-heating unit within one minute after the
exposure to undergo heating. The heating temperature is ordinarily
from 50 to 150.degree. C.
[0346] After the pre-heating, the lithographic printing plate
precursor is subjected to pre-water washing for cooling the
lithographic printing plate precursor and removing a protective
layer.
[0347] The above-described pre-heating and pre-water washing and
development described below are connected with a setter for
exposure to perform the processing in many cases. Needless to say,
it is not restricted to use these units in the connected state and
they may be used separately.
[0348] While the pre-heating step and pre-water washing step are
described, an embodiment omitting these two steps can be used. By
omitting these two steps, the processing becomes simple. A manner
of the omission depends on the performance of the lithographic
printing plate precursor. Occasionally, both or one of these two
steps are omitted.
[0349] The development is described below. In case of the treatment
with hand, for example, a method is used wherein the treatment is
performed by rubbing the entire surface of lithographic printing
plate precursor with a sponge or absorbent cotton sufficiently
impregnated with the processing solution and after the treatment
the lithographic printing plate precursor is thoroughly washed with
water. In case of the immersion treatment, for example, a method is
used wherein the lithographic printing plate precursor is immersed
in a vat or deep tank containing the processing solution for about
60 seconds with stirring and then thoroughly washed with water
while rubbing with an absorbent cotton or sponge.
[0350] In the development processing, a device simplified in the
structure or simplified in the process according to the developing
method of the invention is used. Since the influence of carbon
dioxide in the air is small in comparison with a conventional
alkali development system, the closeness degree between the air and
solution can be decreased. Further, when the oil-desensitization
treatment is performed simultaneously with the development, the
water washing step and oil-desensitization treatment step after the
development as in a conventional method are not indispensable and
provision of one bath or at most two baths is sufficient. Even when
the aqueous solution containing no oil-desensitizing agent, for
example, a water-soluble resin is used, the performance same as in
the conventional system can be obtained by omitting the water
washing and then conducting the oil-desensitization treatment with
a conventional gum solution or the like. Moreover, by using only
one bath of a one-solution developer containing no
oil-desensitizing agent, for example, a water-soluble resin, a
lithographic printing plate can be obtained so that it is possible
to construct a simple processing system although the protecting
property of the surface and oil-desensitizing property are inferior
to the lithographic printing plate obtained according to the
conventional system. Specifically, in such a case, the system can
be constructed by providing two baths. Thus, a device cost can be
decreased and a device can be placed in a space much smaller than
the space necessary for placing the conventional device. The
lithographic printing plate precursor can also be applied to an
automatic development processor (including pre-heat step, pre-water
washing step, development step, water washing step, finishing (gum
coating step) conventionally used in the processing. In such a
case, although the same processing solution can be used in the
development step and finishing step, a processing solution for use
in the development step can be designed in a simpler manner.
Specifically, a construction including one bath of a one-solution
developer containing no oil-desensitizing agent, for example, a
water-soluble resin and employing a conventionally used finishing
solution (gum solution) in the finishing bath is provided. By
constructing as described above, the processing solution can be
applied to an automatic development processor conventionally used
so that the facilities can be effectively employed.
[0351] Since a rubbing member is ordinarily indispensable for the
development processing, the rubbing member, for example, a brush is
provided in the developing bath for removing the non-image area of
the photosensitive layer.
[0352] The developer including the surfactant for use in the
invention can remarkably reduce the load against the rubbing
member, for example, a brush. In case of using a developer of a low
alkaline to acidic region, the non-image area is ordinarily not
removed without conducting development under strong rubbing
conditions for removing the non-image area of the photosensitive
layer. On the contrary, the developer containing the surfactant for
use in the invention enables to conduct development using a rubbing
member comparable with the rubbing member used in a conventional
alkali development and under rubbing conditions (rotation number,
brush pressure) similar to the rubbing conditions used in a
conventional alkali development.
[0353] Needless to say, gum coaters or automatic development
processors known for conventional PS plates or CTP plates can be
used in the system according to the invention. In case of using the
conventional automatic development processor, any processing
system, for example, a processing system wherein the processing
solution prepared in a developing tank is pumped up by a pump and
sprayed through spray nozzles to the exposed lithographic printing
plate precursor, a processing system wherein the exposed
lithographic printing plate precursor is immersed in a bath filled
with the processing solution while conveying the lithographic
printing plate precursor by means of guide rollers or the like in
the solution or a so-called disposable processing system wherein
the processing solution substantially fresh is supplied in an
amount necessary for processing every one sheet of the exposed
lithographic printing plate precursor can be used. In any system,
it is more preferred that a rubbing mechanism by means of a brush,
molton or the like is provided. Also, a device in which a laser
exposure unit and an automatic development processor unit are
incorporated may be employed.
[0354] In the processing method of a lithographic printing plate
precursor according to the invention, methods including the steps
shown below are preferably used.
[0355] In case of one-solution processing:
[0356] Pre-heat.fwdarw.development processing (pre-water
washing+development+gumming).fwdarw.drying
[0357] Pre-heat.fwdarw.pre-water washing.fwdarw.development
processing (development+gumming).fwdarw.drying
[0358] In case of drop-in processing:
[0359] Pre-heat.fwdarw.pre-water washing.fwdarw.development
processing.fwdarw.water washing.fwdarw.gum
treatment.fwdarw.drying
[0360] In the above methods, the pre-heat step can be appropriately
omitted when the sensitivity of lithographic printing plate
precursor is sufficiently high and the output of laser setter is
sufficiently large.
[0361] Further, in order to impart more steadily the
oil-desensitizing performance, in the construction of the
one-solution processing, water washing and gum treatment steps or
only a gum treatment step may be introduced after the development
processing step.
EXAMPLES
[0362] The present invention will be described in more detail with
reference to the following examples, but the invention should not
be construed as being limited thereto.
Examples 1 to 12 and Comparative Examples 1 to 5
[Preparation of Lithographic Printing Plate Precursor]
(Preparation of Support 1)
[0363] An aluminum plate (material: JIS A1050) having a thickness
of 0.3 mm was dipped in an aqueous 10% by weight sodium hydroxide
solution at 60.degree. C. for 25 seconds to effect etching, washed
with running water, neutralized and cleaned with an aqueous 20% by
weight nitric acid solution and then washed with water. The
aluminum plate was subjected to an electrolytic surface roughening
treatment in an aqueous 1% by weight nitric acid solution using an
alternating current with a sinusoidal waveform at an anode time
electricity of 300 coulomb/dm.sup.2. Subsequently, the aluminum
plate was dipped in an aqueous 1% by weight sodium hydroxide
solution at 40.degree. C. for 5 seconds, dipped in an aqueous 30%
by weight sulfuric acid solution at 60.degree. C. for 40 seconds to
effect a desmut treatment, and then subjected to an anodizing
treatment in an aqueous 20% by weight sulfuric acid solution for 2
minutes at a current density of 2 A/dm.sup.2 to form an anodic
oxide film having a thickness of 2.7 g/m.sup.2. The center line
average roughness (Ra) of the thus-treated aluminum plate was
measured using a stylus having a diameter of 2 .mu.m and found to
be 0.25 .mu.m (Ra indication according to JIS B0601). Thereafter,
the aluminum plate was treated with an aqueous 1% by weight sodium
silicate solution at 20.degree. C. for 10 seconds to prepare
Support 1.
(Preparation of Support 2)
[0364] Undercoat Solution (1) shown below was coated using a bar on
the aluminum plate subjected to the anodizing treatment described
above and dried in an oven at 80.degree. C. for 10 seconds to form
an undercoat layer having a dry coating amount of 10 mg/m.sup.2,
thereby preparing Support 2.
TABLE-US-00003 <Undercoat Solution (1)> Undercoat Compound
(1) shown below 0.010 g Methanol 9.00 g Water 1.00 g Undercoat
Compound (1): ##STR00376## Molecular weight: 110,000
(Preparation of Support 3)
[0365] Undercoat Solution (2) shown below was coated using a bar on
the aluminum plate subjected to the anodizing treatment described
above and dried in an oven at 80.degree. C. for 10 seconds to form
an undercoat layer having a dry coating amount of 10 mg/m.sup.2,
thereby preparing Support 3.
TABLE-US-00004 <Undercoat Solution (2)> Undercoat Compound
(2) shown below 0.017 g Methanol 9.00 g Water 1.00 g Undercoat
Compound (2): ##STR00377## ##STR00378## Molecular weight: 110,000
Molar ratio of Copolymerization component: 10/20/70 (in a
left-to-right order of the components of Undercoat Compound
(2))
[0366] On each of the supports described above, Coating Solution
(1) for Photosensitive Layer having the composition shown below was
coated using a bar and dried in an oven at 70.degree. C. for 60
seconds to form a photosensitive layer having a dry coating amount
of 1.1 g/m.sup.2. On the photosensitive layer, Coating Solution (1)
for Protective Layer having the composition shown below was coated
using a bar and dried at 125.degree. C. for 70 seconds to form a
protective layer having a dry coating amount of 0.75 g/m.sup.2,
thereby preparing a lithographic printing plate precursor.
TABLE-US-00005 <Coating Solution (1) for Photosensitive
Layer> Binder polymer (as shown in Table 4 below) 0.54 g
Polymerizable Compound (M-1) shown below 0.48 g Polymerization
Initiator (I-1) shown below 0.08 g Sensitizing Dye (D-1) shown
below 0.06 g Chain Transfer Agent (S-2) shown below 0.07 g
Dispersion of .epsilon.-phthalocyanine pigment 0.40 g [pigment: 15
parts by weight; dispersing agent (allyl methacrylate/methacrylic
acid (80/20) copolymer): 10 parts by weight; solvent
(cyclohexanone/methoxypropyl acetate/1-methoxy-2-propanol = 15
parts by weight/20 parts by weight/40 parts by weight)] Thermal
polymerization inhibitor 0.01 g N-nitrosophenylhydroxylamine
aluminum salt Fluorine-Based Surfactant (F-1) shown below 0.001 g
Polyoxyethylene-polyoxypropylene condensate 0.04 g (Pluronic L44,
produced by ADEKA Corp.) Tetraethylammonium chloride 0.01 g
1-Methoxy-2-propanol 3.5 g Methyl ethyl ketone 8.0 g
M-1 A mixture of the following compounds:
##STR00379##
TABLE-US-00006 <Coating Solution (1) for Protective Layer>
Dispersion of Mica (1) shown below 13.00 g Polyvinyl alcohol
(saponification degree: 98% by mole; 1.30 g polymerization degree:
500) Sodium 2-ethylhexylsulfosuccinate 0.20 g Vinyl
pyrrolidone/vinyl acetate (1/1) copolymer (molecular 0.050 g
weight: 70,000) Surfactant (Emalex 710, produced by Nihon-Emulsion
Co., 0.050 g Ltd.) Water 133.00 g
(Preparation of Dispersion of Mica (1))
[0367] In 368 g of water was added 32 g of synthetic mica (Somasif
ME-100, produced by CO-OP Chemical Co., Ltd.; aspect ratio: 1,000
or more) and the mixture was dispersed using a homogenizer until
the average particle diameter (measured by a laser scattering
method) became 0.5 .mu.m to obtain Dispersion of Mica (1).
[0368] The lithographic printing plate precursors used in
respective examples and comparative examples were prepared
according to the combinations of the support and the photosensitive
layer as shown in Table 4 below.
[Image Exposure, Development Processing and Evaluation of
Lithographic Printing Plate Precursor]
(Image Exposure)
[0369] The lithographic printing plate precursor was subjected to
image exposure by a violet semiconductor laser plate setter Vx9600
(having InGaN semiconductor laser: emission: 405 nm.+-.10
nm/output: 30 mW) produced by FUJIFILM Electronic Imaging, Ltd. As
for the image, halftone dots of 35% were drawn using an FM screen
(TAFFETA 20, produced by Fuji Film Co., Ltd.) in a plate surface
exposure amount of 0.09 mJ/cm.sup.2 and at resolution of 2,438
dpi.
(Development Processing)
[0370] The development processing was performed according to each
of Development Processings 1 to 3 shown below as shown in Table
4.
<Development Processing 1>
[0371] The lithographic printing plate precursor exposed imagewise
was subjected to pre-heat and development processing using an
automatic development processor as shown in FIG. 1 within 30
seconds after the imagewise exposure. In the automatic development
processor shown in FIG. 1, the lithographic printing plate
precursor was subjected to heat treatment at 105.degree. C. for 10
seconds in a heating unit (pre-heat unit) and subjected to
development and gum treatment at the same time in a development
processing unit. Specifically, the lithographic printing plate
precursor pre-heated was immersed in a developer to remove the
photosensitive layer in the non-image area by rubbing and to
undergo the oil-desensitizing treatment at the same time.
Thereafter, the lithographic printing plate precursor was dried in
a drying step. The transporting speed of the lithographic printing
plate precursor was 100 cm/min.
<Development Processing 2>
[0372] The lithographic printing plate precursor exposed imagewise
was subjected to development processing using an automatic
development processor of horizontal transportation system as shown
in FIG. 2 within 30 seconds after the imagewise exposure. In the
development processing, a pre-water washing step is provided just
after the pre-heat step. The heat treatment was conducted at plate
surface temperature of 95.degree. C. for about 10 seconds and then
the protective layer was removed in the pre-water washing step.
After removing the protective layer, the lithographic printing
plate precursor was transported in the horizontal direction and the
photosensitive layer in the non-image area was removed by rubbing
with a brush while supplying the developer from a spray pipe. After
the development, the lithographic printing plate precursor was
dried with warm air in a drying step. The transporting speed of the
lithographic printing plate precursor was 80 cm/min.
<Development Processing 3>
[0373] The lithographic printing plate precursor exposed imagewise
was subjected to development processing using an automatic
development processor (LP1250PLX, produced by Fuji Film Co., Ltd.)
within 30 seconds after the imagewise exposure. The automatic
development processor was composed of a heating unit, a
water-washing unit, a developing unit, a rinsing unit and a
finishing unit in this order. The heating condition in the heating
unit was at 100.degree. C. for 10 seconds. In the developing tank,
the developer shown in Table 4 was supplied. In the water-washing
tank, water was supplied. In the finishing tank, a solution
prepared by diluting a gum solution (FP-2W, produced by Fuji Film
Co., Ltd.) twice with water was supplied. The temperature of the
developer was 28.degree. C. The transportation of the lithographic
printing plate precursor was performed at a transporting speed of
110 cm/min. A schematic view of the automatic development processor
is shown in FIG. 3.
[0374] The compositions of the processing solutions used in the
development processing are shown below, respectively. The pH of
each processing solutions was adjusted at 4.5 with phosphoric acid
and sodium hydroxide.
TABLE-US-00007 TABLE 1 Processing Processing Processing Processing
Processing Processing Processing Solution 1 Solution 2 Solution 3
Solution 4 Solution 5 Solution 6 Solution 7 Water 8249.8 8179.8
8179.8 8179.8 8179.8 8279.8 8879.8 Gum arabic 250 250 250 250 250
250 250 Enzyme-modified potato starch 700 700 700 700 700 700 700
Sodium salt of dioctylsulfosuccinic acid ester 50 50 50 50 50 50 50
Ammonium primary phosphate 10 10 10 10 10 10 10 Citric acid 10 10
10 10 10 10 10 2-Bromo-2-nitropropane-1,3-diol 0.1 0.1 0.1 0.1 0.1
0.1 0.1 2-Methyl-4-isothiazolin-3-one 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Amphoteric Surfactant W-2 700 700 700 700 700 700 -- Anionic
Surfactant A-1 30 100 -- -- -- -- 100 Anionic Surfactant A-5 -- --
100 -- -- -- -- Anionic Surfactant A-8 -- -- -- 100 -- -- --
Anionic Surfactant A-11 -- -- -- -- 100 -- -- Total 10000 (g) 10000
(g) 10000 (g) 10000 (g) 10000 (g) 10000 (g) 10000 (g)
TABLE-US-00008 TABLE 2 Processing Processing Processing Solution 8
Solution 9 Solution 10 Water 7749.8 7749.8 7749.8 Benzyl alcohol 50
50 50 Ethylene glycol 50 50 50 Glycerin 50 50 50 Gum arabic 250 250
250 Enzyme-modified potato starch 700 700 700 Sodium salt of
dioctylsulfosuccinic 50 50 50 acid ester Ammonium primary phosphate
10 10 10 Citric acid 10 10 10 2-Bromo-2-nitropropane-1,3-diol 0.1
0.1 0.1 2-Methyl-4-isothiazolin-3-one 0.1 0.1 0.1 Amphoteric
Surfactant W-1 1000 1000 1000 Anionic Surfactant A-1 80 -- --
Compound A -- 80 -- Compound B -- -- 80 Total 10000 (g) 10000 (g)
10000 (g) Compound A: ##STR00380## Compound B:
C.sub.12H.sub.25--O--(CH.sub.2CH.sub.2O).sub.n--OH (n = 10)
TABLE-US-00009 TABLE 3 Processing Processing Solution 11 Solution
12 Water 9050 8790 Ammonium primary phosphate 10 10 Amphoteric
Surfactant W-2 850 850 Anionic Surfactant A-1 90 350 Total 10000
(g) 10000 (g)
[0375] With respect to the development processing, in addition to
the development processing (fresh solution development) using the
processing solution as described above, development processing
(fatigued solution development) using a processing solution
prepared by adding 1 part by weight of the binder polymer included
in the photosensitive layer of the lithographic printing plate
precursor to be processed to the processing solution was
conducted.
(Evaluation)
<Evaluation of Developing Property>
[0376] With the lithographic printing plate obtained by performing
the development processing, reflection density (OD) of the
non-image area was measured by a reflection densitometer produced
by Gretag Macbeth in a cyan mode. The reflection density of the
aluminum support measure in the same manner was 0.65. Therefore,
when the reflection density of the non-image area is 0.65, it
indicates that the photosensitive layer is substantially removed,
that is, the developing property is good.
<Evaluation of Printing Stain>
[0377] The lithographic printing plate after the development
processing was mounted on a printing machine, SOR-M, produced by
Heidelberg, and printing was performed at a printing speed of 6,000
sheets per hour using dampening water (EU-3 (etching solution,
produced by Fuji Film Co., Ltd.))/water/isopropyl alcohol=1/89/10
(by volume ratio)) and TRANS-G (N) black ink (produced by
Dai-Nippon Ink & Chemicals, Inc.). On the 500th printed
material, stain (background satin) in the non-image area was
observed and when the background stain was not recognized, the
observation result of the printed material just after the
initiation of printing was also considered to evaluate the printing
stain according to the following criteria:
.largecircle.: Background satin did not occur even just after the
initiation of printing (good). .DELTA.: Slight background satin
occurred only just after the initiation of printing. .DELTA.x:
Slight background satin partly occurred. x: Background satin
occurred.
[0378] The results of the evaluation are shown in table 4.
TABLE-US-00010 TABLE 4 Fresh Solution Fatigued Solution Binder
Polymer Of Development Development Development Photosensitive
Processing Developing Printing Developing Printing Evaluation
Processing Layer Support Solution Remarks Property Stain Property
Stain Judgment Example 1 Development Binder Polymer 1 Support 2
Processing 0.65 .largecircle. 0.65 .DELTA. OK Processing 1 Solution
1 Example 2 Processing 0.65 .largecircle. 0.65 .largecircle. OK
Solution 2 Example 3 Processing 0.65 .largecircle. 0.65
.largecircle. OK Solution 3 Example 4 Processing 0.65 .largecircle.
0.65 .largecircle. OK Solution 4 Example 5 Processing 0.65
.largecircle. 0.65 .largecircle. OK Solution 5 Comparative
Processing 0.65 .largecircle. 0.65 x NG Example 1 Solution 6
Comparative Processing 1.51 x 1.51 x NG Example 2 Solution 7
Example 6 Development Binder Polymer 1 Support 2 Processing 0.65
.largecircle. 0.65 .largecircle. OK Processing 1 Solution 8
Comparative Processing 0.65 .largecircle. 0.65 .DELTA.x NG Example
3 Solution 9 Comparative Processing 0.65 .largecircle. 0.65 x NG
Example 4 Solution 10 Example 7 Development Binder Polymer 1
Support 2 Processing With 0.65 .largecircle. 0.65 .largecircle. OK
Processing 1 Solution 11 Separate Gumming Step Comparative
Processing With 0.72 .DELTA.x 0.76 .DELTA.x NG Example 5 Solution
12 Separate Gumming Step Example 8 Development Binder Polymer 1
Support 2 Processing 0.65 .largecircle. 0.65 .largecircle. OK
Processing 2 Solution 2 Example 9 Development Binder Polymer 1
Support 2 Processing 0.65 .largecircle. 0.65 .largecircle. OK
Processing 3 Solution 11 Example 10 Development Binder Polymer 2
Support 1 Processing 0.65 .largecircle. 0.65 .largecircle. OK
Processing 1 Solution 3 Example 11 Development Binder Polymer 3
Support 3 Processing 0.65 .largecircle. 0.65 .largecircle. OK
Processing 1 Solution 5 Example 12 Development Binder Polymer 1
Support 2 Processing 0.65 .largecircle..largecircle. 0.65
.largecircle. OK Processing 1* Solution 2 Binder Polymer 1:
##STR00381## ##STR00382## MW: 59000 Binder Polymer 2: ##STR00383##
MW: 80000 Binder Polymer 3 ##STR00384## Mw: 55000 Development
Processing 1*: In Example 12, the plate surface exposure amount was
changed from 0.09 mJ/cm.sup.2 to 0.20 mJ/cm.sup.2 and the
development processing was carried out according to Development
Processing 1 except for eliminating pre-heat.
[0379] From the results shown in Table 4, it can be seen that
although the processing method of a lithographic printing plate
precursor according to the invention is characterized by processing
with the processing solution containing both the amphoteric
surfactant and the specific anionic surfactant, when the processing
solution not containing the anionic surfactant is used as shown in
Comparative Example 1, the printing stain occurs according to the
processing with the fatigued solution though the printing stain do
not occur according to the processing with the fresh solution. In
Comparative Example 1, the reflection density of the non-image area
is an equivalent level to that of the aluminum support in the
processing with the fresh solution and in the processing with the
fatigued solution. However, the fact of the matter is that when a
certain amount or more of the photosensitive layer component is
dissolved in the processing solution as in the fatigued solution,
readsorption of the binder component on the surface of support from
the processing solution occurs simultaneously with removal of the
photosensitive layer by the development. Thus, since only the
binder component adsorbs on the surface of support without the
pigment component, the printing stain occurs even when the
reflection density of the non-image area is an equivalent level to
that of the support.
[0380] On the contrary, it is apparent that in Example 1, the
printing stain in the processing with the fatigued solution is
improved in an acceptable level. Further, in Example 2 wherein the
amount of the anionic surfactant is increased, the greater effect
is obtained and the printing stain is not recognized even just
after the initiation of printing. This is because that the
readsorption of the binder component on the surface of support in
the processing with the fatigued solution is prevented.
[0381] It can also be seen that the good results are obtained even
when the kind of the anionic surfactant is varied as shown in
Examples 3 to 5. Further, it can be seen that the good results are
obtained even when the kind of the photosensitive layer component
or the support is varied as shown in Examples 10 and 11.
[0382] On the contrary, when the amphoteric surfactant is
eliminated, the development can be hardly conducted as shown in
Comparative Example 2.
[0383] From these results, it can be understood that the processing
of a lithographic printing plate precursor which is excellent in
the developing property and does not cause the printing stain is
achieved by the combination of the amphoteric surfactant and the
specific anionic surfactant.
[0384] Moreover, the good results are obtained even when the
processing solution containing an organic solvent is used as shown
in Example 6. On the contrary, in the case of using an anionic
surfactant having the total number of carbon atoms outside the
scope of the invention (as in Comparative Example 3) or in the case
of using a nonionic surfactant in place of the anionic surfactant
(as in Comparative Example 4), the printing stain occurs.
[0385] As shown in Example 7, the good results are also obtained
even when the aqueous solution which does not contain the
water-soluble resin is used. In Example 7, after the development
processing, the water washing and gum treatment (Gum solution FN-6)
were conducted by connecting a water washing unit and a gumming
unit to the development processing unit. On the other hand, in
Comparative example 5 wherein the anionic surfactant is excessively
added, the developing property is clearly decreased and the
printing stain occurs not only in the processing with the fatigued
solution but also in the processing with the fresh solution.
[0386] As shown in Example 8, the good printed materials are
obtained without the occurrence of printing stain in the processing
with the fatigued solution even when the horizontal transportation
system is used.
[0387] As shown in Example 9, the good developing property is
obtained and the occurrence of printing stain is prevented even
when the automatic development processor which is ordinarily
employed in a conventional alkali development system is used.
[0388] Furthermore, as shown in Example 12, the good results are
obtained in the case of performing the image recording with a high
exposure amount and eliminating the pre-heating.
[0389] This application is based on Japanese Patent application JP
2007-256706, filed Sep. 28, 2007, the entire content of which is
hereby incorporated by reference, the same as if fully set forth
herein.
[0390] Although the invention has been described above in relation
to preferred embodiments and modifications thereof, it will be
understood by those skilled in the art that other variations and
modifications can be effected in these preferred embodiments
without departing from the scope and spirit of the invention.
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