U.S. patent application number 09/770281 was filed with the patent office on 2001-09-06 for azomethine dye precursor, image-forming material, and image-forming method.
Invention is credited to Arai, Yoshimitsu, Matsumoto, Hirotaka, Sato, Hiroshi, Yumoto, Masatoshi.
Application Number | 20010019806 09/770281 |
Document ID | / |
Family ID | 18545278 |
Filed Date | 2001-09-06 |
United States Patent
Application |
20010019806 |
Kind Code |
A1 |
Sato, Hiroshi ; et
al. |
September 6, 2001 |
Azomethine dye precursor, image-forming material, and image-forming
method
Abstract
The present invention related to an azomethine dye precursor
represented by the following general formula (1) and the
image-forming material and image-forming method using the
azomethine dye precursor: wherein Ar represents an aryl group or a
heterocyclic group which may each have a substituent; X represents
a bivalent group linking a carbon atom and a nitrogen atom; and Cp
represent a coupler residue which may or may not form a ring.
General formula 1
Inventors: |
Sato, Hiroshi;
(Shizuoka-ken, JP) ; Yumoto, Masatoshi;
(Shizuoka-ken, JP) ; Arai, Yoshimitsu;
(Shizuoka-ken, JP) ; Matsumoto, Hirotaka;
(Shizuoka-ken, JP) |
Correspondence
Address: |
SUGHRUE, MION, ZINN, MACPEAK & SEAS, PLLC
Suite 800
2100 Pennsylvania Avenue
Washington
DC
20037-3213
US
|
Family ID: |
18545278 |
Appl. No.: |
09/770281 |
Filed: |
January 29, 2001 |
Current U.S.
Class: |
430/138 ;
430/280.1; 430/281.1; 430/283.1; 430/284.1; 430/285.1; 430/287.1;
430/288.1; 430/292; 430/332; 430/333; 430/334; 430/336; 430/339;
430/341; 430/343; 430/944; 430/945 |
Current CPC
Class: |
Y10S 430/145 20130101;
C09B 55/00 20130101; B41M 5/323 20130101; C09B 67/0077 20130101;
G03C 1/49854 20130101; G03C 7/32 20130101 |
Class at
Publication: |
430/138 ;
430/280.1; 430/285.1; 430/292; 430/288.1; 430/284.1; 430/287.1;
430/283.1; 430/281.1; 430/944; 430/945; 430/333; 430/334; 430/336;
430/332; 430/339; 430/341; 430/343 |
International
Class: |
G03C 001/735; G03C
001/73; G03C 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2000 |
JP |
2000-18425 |
Claims
What is claimed is:
1. An azomethine dye precursor represented by the following general
formula (1): 49wherein Ar represents an aryl group or a
heterocyclic group which may each have a substituent; X represents
a bivalent group linking a carbon atom and a nitrogen atom; and Cp
represent a coupler residue which may or may not form a ring.
2. An azomethine dye precursor according to claim 1, wherein Ar is
a group represented by the following structural formula (4):
50wherein R.sup.12 represents a substituent; and R.sup.13 and
R.sup.14 each represents a hydrogen atom, an alkyl group, an aryl
group, or a heterocyclic group, with the proviso that the alkyl
group, the aryl group, and the heterocyclic group of R.sup.13 and
R.sup.14 may have a substituent.
3. An azomethine dye precursor according to claim 1, wherein the
ring formed by X, N, and C is a 5-membered ring, a 6-membered ring,
or a 7-membered ring.
4. An azomethine dye precursor according to claim 1, wherein Cp is
an acylacetanilide, a pyrazolotriazole, a pyrazolone, a pyridone, a
barbituric acid, apyrrolotriazole, a naphthol, a phenol, or an
imidazole.
5. An image-forming material comprising a support having thereon an
image-forming layer containing at least one deblocking agent and at
least one azomethine dye precursor represented by the following
general formula (1): 51wherein Ar represents an aryl group or a
heterocyclic group which may each have a substituent; X represents
a bivalent group linking a carbon atom and a nitrogen atom; and Cp
represent a coupler residue which may or may not form a ring.
6. An image-forming material according to claim 5, wherein the
deblocking agent is at least one selected from an acid, a base, an
oxidizing agent, an alkylating agent, and a metal salt.
7. An image-forming material according to claim 5, wherein any one
of the azomethine dye precursor and the deblocking agent is
enclosed in microcapsules.
8. An image-forming material according to claim 5, further
comprising at least one other image-forming layer containing at
least one dye precursor which develops a hue different from that of
the azomethine dye precursor.
9. An image-forming material according to claim 5, wherein the
image-forming layer further contains at least one
photopolymerization initiator and at least one polymerizable
compound.
10. An image-forming material according to claim 9, wherein the
deblocking agent has a polymerizable group and acts also as a
polymerizable compound.
11. An image-forming material according to claim 9, wherein the
photopolymerization initiator consists of a dye and a radical
generator capable of interacting with the dye so as to generate a
radical.
12. An image-forming material according to claim 9, wherein the
photopolymerization initiator consists of a dye and an organoboron
compound.
13. An image-forming material according to claim 12, wherein the
organoboron compound is an organoboron compound represented by the
general formula (2): 52wherein R.sup.1, R.sup.2, R.sup.3, and
R.sup.4 each represents an alkyl group, an aryl group, a
heterocyclic group, or --SiR.sup.5R.sup.6R.sup.7 where R.sup.5,
R.sup.6, and R.sup.7 each represents an alkyl group or an aryl
group; and G.sup.+ represents a group capable of forming a
cation.
14. An image-forming material according to claim 8, wherein each of
the image-forming layers further contains a photopolymerization
initiator consisting of a spectral sensitizing dye having
absorption wavelengths which differ from each other and a radical
generator capable of interacting with the dye so as to generate a
radical.
15. An image-forming method comprising the steps of: (a) forming an
image-forming material by disposing an image-forming layer on a
support, with the image-forming layer containing at least one
deblocking agent and at least one azomethine dye precursor
represented by the following general formula (1): 53wherein Ar
represents an aryl group or a heterocyclic group which may each
have a substituent; X represents a bivalent group linking a carbon
atom and a nitrogen atom; and Cp represent a coupler residue which
may or may not form a ring; (b) producing a visible image by
heating and/or pressing the image-forming material.
16. An image-forming method according to claim 15, wherein the step
in which the image is made visible includes heating and/or pressing
of substantially the entire surface of the image-forming layer of
the image-forming material, further comprising the step of: a
latent-image forming, which precedes the step in which the image is
made visible, and in which the image-forming layer containing at
least one photopolymerization initiator and at least one
polymerizable compound is irradiated image-wise with light which is
absorbed by the photopolymerization initiator so that a
polymerization initiating species is developed from the
photopolymerization initiator in the portions irradiated with the
light and the polymerizable compound is polymerized to thereby form
a latent image.
17. An image-forming method according to claim 15, wherein the step
in which the image is made visible includes heating and/or pressing
of substantially the entire surface of the image-forming layer of
the image-forming material, further comprising the step of: a
latent-image forming, which precedes the step in which the image is
made visible, and in which the multilayer image-forming layers each
containing at least one different azomethine dye precursor, at
least one different photopolymerization initiator and a
polymerizable compound are irradiated image-wise with lights of
different wavelengths which are absorbed by the photopolymerization
initiator of each of the image-forming layers so that a
polymerization initiating species is developed from each
photopolymerization initiator in the portions irradiated with the
respective light and the polymerizable compound is polymerized to
form a latent image and thereby form a multicolor image.
18. An image-forming method according to claim 15, further
comprising the step of a fixing in which the image is fixed by
irradiating the entire surface of the image-forming layer with
light.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an azomethine dye precursor
as a useful novel compound.
[0003] Further, the present invention relates to a single-color or
multicolor image-forming material containing the azomethine dye
precursor and an image-forming method using the image-forming
material.
[0004] 2. Description of the Related Art
[0005] Heretofore, various dry-type image-forming methods that do
not use a liquid developing agent and the like and do not produce
wastes have been studied. Among these methods, a method, which uses
a light-hardenable composition as a component of the image-forming
layer of a recording material (an image-forming material), has been
the focus of much attention.
[0006] This method is characterized in that the exposure to light
causes the composition that hardens on exposure to light contained
in the image-forming layer to harden and thereby form a latent
image, while the component, contained in the unexposed portions of
the image-forming layer which contributes to the color-developing
reaction, is transferred by heat or pressure within the
image-forming layer to thereby form a colored image. When a
recording material based on such a method is used, the process
comprises exposing the image-forming material to light through an
image original to thereby form a latent image by hardening the
exposed portions, and applying heat or pressure to the recording
material to thereby cause the component, contained in unhardened
portions (unexposed portions) and which contributes to the color
development reaction, to move so as to form a visible image.
[0007] Conventionally known as such a recording material is a
recording material which is disclosed in Japanese Patent
Application Laid-Open (JP-A) No. 61-123838 and which is formed by
laminating the following: a layer containing a photopolymerizable
composition composed of a vinyl monomer having an acidic group and
a photopolymerization initiator; an isolating layer; and a layer
composed of an electron-donating colorless dye. In the case of this
recording material, since the thermal diffusion of the acidic group
does not occur in the non-image portions, i.e., portions hardened
by photopolymerization, the non-image portions are free from a
coloration problem. However, the problem of this recording material
is that the density of the developed color is low and the
durability is low.
[0008] Recording materials, in which the low density of developed
color is improved, include the recording materials described in
JP-A No. 3-87827 and JP-A No. 4-211252. The former is a
two-component, photo- and heat-sensitive, color-developing
recording material in which one of the two components is enclosed
in microcapsules while the other component is contained outside the
microcapsules (1) as a hardenable compound of the composition which
hardens on exposure to light or (2) together with the composition
which hardens on exposure to light. The latter is a photo- and
heat-sensitive recording material comprising a support having
thereon a layer having microcapsules enclosing an electron-donating
colorless dye and a composition which hardens on exposure to light
containing an electron-accepting compound, a polymerizable vinyl
monomer, and a photopolymerization initiator outside the
microcapsules. However, none of these two recording materials
reached a fully satisfactory level in terms of durability of images
because an electron-donating colorless dye, i.e., a so-called
phthalide compound, was used as the dye precursor.
[0009] Likewise, recording materials, described in Japanese Patent
Application Publication (JP-B) Nos. 64-7378, 64-7377, 64-7376, and
so on, are known as examples of photo- and pressure-sensitive
paper. However, none of these recording materials reached a fully
satisfactory level in terms of durability of images because the dye
precursors used in these recording materials were also phthalide
compounds.
[0010] JP-B No. 5-42359 discloses a thermal image-forming method in
which images can be formed by heating image-wise, a recording
material having in the image - forming layer thereof a compound
having a thermally unstable carbamate moiety and capable of causing
an irreversible monomolecular fission, to thereby cause the
compound to thermally decompose and undergo a visible change
image-wise. Although a dye precursor besides a phthalide compound
can also be used in this method, since the image-wise color
development is carried out by heat alone, this method is associated
with the following problems. The problems are that, since a large
amount of heat is required when images are written, the apparatus
is necessarily large and the processing speed is slow and that
fogging tends to occur in non-image portions due to remaining heat
or accumulated heat derived from the writing step. Another problem
is a storability problem that, since the color development is
controlled by heat alone, fogging tends to occur during
storage.
[0011] Japanese Patent No. 2744101 describes a heat-sensitive
element which forms images when heated image-wise and which
comprises a dye precursor substituted by a blocking group that can
be thermally removed when heated and a leaving group that
irreversibly leaves when heated. This heat-sensitive element is
also associated with problems similar to those of the thermal
image-forming method described in JP-B No. 5-42359 because the
color developability is controlled by heat alone. Another problem
is a storability problem that, since the developed color is not
fixed, the dye precursor is gradually decomposed in the white
background portions (non-image portions) and fogging tends to
occur, for example, under a thermally enforced condition.
[0012] Accordingly, a dye precursor, which develops color by an
element other than heat or by the action of heat and an element
other than heat, is desired.
[0013] Further, JP-A No. 5-204087, PCT National Publication No.
8-507885, and PCT National Publication No. 10-502460 disclose
photo- and heat-sensitive photographing materials using dye
precursors. However, since these materials use silver halides as a
photosensitive material, a need exists for an image-forming
material capable of forming images in a perfectly dry processing
system without using silver halides (hereinafter referred to as
"non-silver salt" system) from the standpoint of storability, ease
in handling, etc.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is to provide an
azomethine dye precursor as a useful novel compound which can
develop color by the action of a deblocking agent or by the action
of heat and a deblocking agent and which, when used in the
image-forming layer of an image-forming material, exhibits good
color development by a small amount of energy and provides images
having very good durability.
[0015] Another object of the present invention is to provide a
single-color or multicolor image-forming material capable of
forming high-quality and highly durable images in a rapid way in a
perfectly dry processing system, which does not require a
developing solution or the like and does not produce wastes, and to
provide an image forming method using the image-forming
material.
[0016] The objects described can be achieved by the present
invention described below. That is, the first aspect of the present
invention is an azomethine dye precursor represented by the
following general formula (1): 2
[0017] In the general formula (1), Ar represents an aromatic ring
which may have a substituent or a heterocycle; and X represents a
bivalent group linking a carbon atom and a nitrogen atom. Cp
represent a coupler residue which may or may not form a ring.
[0018] The second aspect of the present invention is an
image-forming material comprising a support having thereon an
image-forming layer containing at least one deblocking agent and at
least one azomethine dye precursor represented by the following
general formula (1): 3
[0019] wherein Ar represents an aryl group or a heterocyclic group
which may each have a substituent; X represents a bivalent group
linking a carbon atom and a nitrogen atom; and Cp represent a
coupler residue which may or may not form a ring.
[0020] The third aspect of the present invention is an
image-forming method comprising the steps of:
[0021] (a) forming an image-forming material by disposing an
image-forming layer on a support, with the image-forming layer
containing at least one deblocking agent and at least one
azomethine dye precursor represented by the following general
formula (1): 4
[0022] wherein Ar represents an aryl group or a heterocyclic group
which may each have a substituent; X represents a bivalent group
linking a carbon atom and a nitrogen atom; and Cp represent a
coupler residue which may or may not form a ring;
[0023] (b) producing a visible image by heating and/or pressing the
image-forming material.
[0024] The azomethine dye precursor of the present invention
produces an azomethine dye (i.e., develops a color) by the action
of a deblocking agent at room temperature or in a temperature range
in which the azomethine dye precursor does not develop a color on
its own by being heated alone unless a deblocking agent is present.
The use of the azomethine dye precursor of the present invention in
an image-forming layer of the image-forming material enables the
image-forming material to develop a good color using a small amount
of energy, imparts high sensitivity, and raises durability such as
storability of the images obtained to a very good level.
[0025] Unlike an image-forming material and an image-forming method
using a dye precursor which develops a color by heat alone, the
image-forming material and the image-forming method of the present
invention, which uses a novel azomethine dye precursor capable of
developing a color when brought into contact with a deblocking
agent, has a high sensitivity and can rapidly form a high-quality
and highly durable image whose non-image portions are less likely
to produce fogging. If necessary, at least one photopolymerization
initiator and at least one polymerizable compound may be
incorporated in the image-forming layer; and this incorporation
enables the image-forming layer to have high sensitivity to light
and to provide highly durable images having a good hue.
Furthermore, if necessary, the thus-obtained image, including image
portions and background portions (non-image portions), may be
polymerized; and this polymerization can fix the image and thus
raise the durability to a higher level.
BRIEF DESCRIPTION OF THE DRAWING
[0026] FIG. 1 is an enlarged cross-sectional view of the
image-forming material prepared in the examples.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] [Azomethine Dye Precursor]
[0028] First, the azomethine dye precursor of the present invention
is explained below. The azomethine dye precursor of the present
invention is a dye precursor, which, when brought into contact with
a deblocking agent, produces an azomethine dye (i.e., develops a
color), and is a dye precursor represented by the following general
formula (1). 5
[0029] In the general formula (1), Ar represents an aryl group or a
heterocyclic group which may each have a substituent; and X
represents a bivalent group linking a carbon atom and a nitrogen
atom. Cp represents a coupler residue which may or may not form a
ring.
[0030] Ar in the general formula (1) represents an aryl group or a
heterocyclic group which may each have a substituent, wherein
examples of the aryl group which may have a substituent include,
for example, groups represented by the following structural formula
(3). 6
[0031] In the structural formula (3), R.sup.11 and R.sup.12 each
represents a hydrogen atom, an alkyl group, an aryl group, a
halogen atom, a cyano group, a nitro group, SO.sub.3H, a
heterocyclic group, NR.sup.13R.sup.14, OR.sup.15, CO.sub.2H,
SR.sup.15, COR.sup.16, CO.sub.2R.sup.18, SO.sub.2R.sup.16,
SOR.sup.16, CONR.sup.17R.sup.18. R.sup.11 is preferably
NR.sup.13R.sup.14. R.sup.11 and R.sup.12 may join together to form
a ring. When R.sup.11 and R.sup.12 each has a dissociative proton
such as OH, CO.sub.2H, or SO.sub.3H, a salt may be formed with an
inorganic cation or an organic cation such as a tetraalkylammonium
cation.
[0032] R.sup.13 and R.sup.14 each represents a hydrogen atom, an
alkyl group, an aryl group, or a heterocyclic group. And the alkyl
group, the aryl group, and the heterocyclic group may each have a
substituent.
[0033] Preferably, R.sup.13 and R.sup.14 are each a hydrogen atom,
an alkyl group having 1 to 30 carbon atoms, and an aryl group
having 6 to 20 carbon atoms. Specific examples of R.sup.13 and
R.sup.14 include hydrogen, methyl, ethyl, propyl, butyl, octyl,
octadecyl, hydroxyethyl, methanesulfonylaminoethyl, phenoxyethyl,
cyanoethyl, benzoyloxyethyl, cyclohexyl, phenyl, tolyl,
methoxyphenyl, and benzyl.
[0034] NR.sup.13R.sup.14 may form a ring which may contain a
heteroatom such as O, S, N by R.sup.13 and R.sup.14, or the like,
or otherwise may form a ring together with the phenyl ring by which
NR.sup.13R.sup.14 is substituted.
[0035] R.sup.15 represents a hydrogen atom, COR.sup.16,
CO.sub.2R.sup.16, SO.sub.2R.sup.16 CONR.sup.17R.sup.18, an alkyl
group, or an aryl group; and R.sup.16 represents a hydrogen atom,
an alkyl group, an aryl group, or a heterocyclic group. R.sup.17
and R.sup.18 each represents a hydrogen atom, an alkyl group, an
aryl group, or a heterocyclic group. R.sup.15 is preferably a
hydrogen atom, COR.sup.16, CO.sub.2R.sup.16, SO.sub.2R.sup.16,
CONR.sup.17R.sup.18, an alkyl group, or an aryl group, each having
1 to 40 carbon atoms. Specific examples of R.sup.15 include
hydrogen atom, methyl, ethyl, octyl, benzyl, phenyl, acetyl,
benzoyl, ethoxycarbonyl, phenylsulfonyl, and
dibutylaminocarbonyl.
[0036] The above-mentioned SO.sub.3H, CO.sub.2H, and OH may be in
salt form.
[0037] The alkyl group, the aryl group, and the heterocyclic group
listed as R.sup.11.about.R.sup.18 in the general formula (1) may
have substituents. Examples of the substituents include an alkyl
group, an aryl group, a hydroxyl group, a nitro group, a cyano
group, a halide group, an alkylsulfonyl group, an arylsulfonyl
group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl
group, an amino group, an alkylamino group, a dialkylamino group,
an acylamino group, an alkylsulfonylamino group, an
arylsulfonylamino group, a carbamoyl group, a sulfamoyl group, an
alkylthio group, an arylthio group, a heterocyclic group, an
arylamino group, a diarylamino group, an arylalkylamino group, an
alkoxy group, and an aryloxy group.
[0038] Examples of the heterocyclic group of Ar as an heterocyclic
group which may have a substituent in the general formula (1)
include pyridine, pyrimidine, triazine, pyridazine, pyrazine,
furan, thiophene, pyrrole, pyrazole, triazole, isooxazole,
isothiazole, imidazole, oxazole, thiazole, and tetrazole. Examples
of the substituents include those illustrated by R.sup.11 and
R.sup.12 described previously.
[0039] In the general formula (1), Ar may be fused with an aromatic
ring or a heterocycle. The alkyl group included in Ar may or may
not be saturated, or otherwise may be a ring.
[0040] Cp in the general formula (1) represents a coupler residue.
As these couplers, all couplers known in the field of silver salt
photography, diazo heat-sensitive recording materials, etc. can be
used.
[0041] Examples of the couplers are described in Research
Disclosure No. 17643, VII, -C.about.G and in Research Disclosure
No. 307105, VII, -C.about.G. Among these couplers, preferable are
non-diffusive couplers having hydrophobic groups that are called
ballast groups, couplers having no hydrophobic groups, and
polymerized couplers. The couplers that are preferably used in the
present invention include cyan couplers, such as naphthol-based
couplers, phenol-based couplers, and so on. Examples of the cyan
couplers are described in U.S. Pat. Nos. 2,369,929, 2,772,162,
2,801,171, 2,895,826, 3,446,622, 3,758,308, 3,772,002, 4,052,212,
4,126,396, 4,146,396, 4,228,233, 4,254,212, 4,296,199, 4,296,200,
4,327,173, 4,333,999, 4,334,011, 4,343,011, 4,427,767, 4,451,559,
4,690,889, and 4,775,616, German Laid-Open Patent Application No.
3,329,729, European Patent Nos. 121,365A and 249,453A, JP-A No.
61-42,658, etc. Examples of magenta couplers include
imidazole[1,2-b]pyrazoles described in U.S. Pat. No. 4,500,630 and
so on, and pyrazolo[1,5-b] [1,2,4]triazoles described in U.S. Pat.
Nos. 4,540,654 and so on.
[0042] Other examples include a pyrazolotriazole coupler described
in JP-A No. 61-65,245 in which a branched alkyl group is linked
directly to a 2-, 3-, or 6-position of the pyrazolotriazole ring; a
pyrazoloazole coupler described in JP-A No. 61-65,245 which
contains in the molecule thereof a sulfonamide group; a
pyrazoloazole coupler described in JP-A No. 61-147,254 which has an
alkoxyphenylsulfonamide ballast group; a pyrazolotriazole coupler
described in European Patent (Laid Open) Nos. 226,849 and 294,785
in which the pyrazolotriazole ring has an alkoxy or aryloxy group
in a 6-position; and couplers described in U.S. Pat. Nos.
3,061,432, 3,725,067, 4,310,619, 4,351,897, and 4,556,630, European
Patent No. 73,636, JP-A Nos. 55-118,034, 60-35,730, 60-43,659,
60-185,951, and 61-72,238, International Patent Application Laid
Open No. WO 88/04795, Research Disclosure No. 24220, Research
Disclosure No. 24230, and so on. Examples of yellow couplers
include couplers described in U.S. Pat. Nos. 3,933,501, 3,973,968,
4,022,620, 4,248,961, 4,314,023, 4,326,024, 4,401,752, and
4,511,649, European Patent No. 249,473A, JP-B No. 58-10,739, U.K.
Patent Nos. 1,425,020 and 1,476,760, and so on.
[0043] Typical examples of dye-forming couplers that are
polymerized are described in U.S. Pat. Nos. 3,451,820, 4,080,211,
4,367,282, 4,409,320, and 4,576,910, European Patent No. 341,188A,
U.K. Patent No. 2,102,137, and so on.
[0044] Other couplers include those described, for example, in
Japanese Patent Application No. 9-260336, JP-A No. 11-116544, and
so on.
[0045] Next, the linking group X in the general formula (1) is
described below. Preferably, X is a bivalent group having the
following structural formula.
--Q.sup.1--(Q.sup.2).sub.l--(Q.sup.3).sub.m(Q.sup.4).sub.n--Q.sup.5--
[0046] In the formula described above, Q.sup.1, Q.sup.2, Q.sup.3,
Q.sup.4, and Q.sup.5 are linking groups constituting X; and l, m,
and n are each 0 or an integer of 1. Examples of Q.sup.1, Q.sup.2,
Q.sup.3, Q.sup.4, and Q.sup.5 include the following groups. Q.sup.1
is on the side linked to the carbon atom while Q.sup.5 is on the
side linked to the nitrogen atom. 7
[0047] In the formulae described above, Y represents an oxygen atom
or a sulfur atom.
[0048] In the formulae described above, R.sup.19, R.sup.20 and
R.sup.21 each represents a substituent, examples of which include
the substituents listed as examples of R.sup.11. R.sup.19,
R.sup.20, and R.sup.21 may each form a ring with other atoms in
X.
[0049] In the formulae described above, R.sup.12 represents a
substituent, examples of which include the substituents listed as
examples of R.sup.11. R.sup.22 may form a ring with other atoms in
X.
[0050] In the formulae described above, R.sup.23 and R.sup.24 each
represents a substituent, examples of which include the
substituents listed as examples of R.sup.11. R.sup.23 and R.sup.24
may each form a ring with other atoms in X.
[0051] In the formulae described above, R.sup.25 represents a
substituent, examples of which include the substituents listed as
examples of R.sup.11. R.sup.25 may form a ring with other atoms in
X.
[0052] In the formula described above, Q.sup.1, Q.sup.2, Q.sup.3,
Q.sup.4, and Q.sup.5 may each independently form an aryl group or a
heterocyclic group (i.e., a so-called arylene group or a bivalent
heterocyclic group). Examples of the aryl group include a phenyl
group, a chlorophenyl group, a methoxyphenyl group, a naphthyl
group, and the like. Examples of the heterocyclic group include
pyrazole, imidazole, triazole, tetrazole, pyridine, pyrimidine,
triazine, pyridazine, pyrazine, furan, thiophene, pyrrole,
isooxazole, isothiazole, oxazole, thiazole, and the like. The aryl
group and the bivalent heterocyclic group may have in any position
thereof the linking bonds. The aryl group and the heterocyclic
group may each have a substituent. Examples of the substituent
group include an alkyl group, an aryl group, a hydroxyl group, a
nitro group, a cyano group, a halide group, an alkylsulfonyl group,
an arylsulfonyl group, an alkoxycarbonyl group, an aryloxycarbonyl
group, an acyl group, an amino group, an alkylamino group, a
dialkylamino group, an acylamino group, an alkylsulfonylamino
group, an arylsulfonylamino group, a carbamoyl group, a sulfamoyl
group, an alkylthio group, an arylthio group, a heterocyclic group,
an alkoxy group, and an aryloxy group. The aryl group may be fused
with a heterocycle; and the heterocyclic group may be fused with an
aromatic ring. The linkage may be at any position on the ring of
the aryl group or of the heterocyclic group.
[0053] In the formula described above, the heterocyclic rings in
Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.4, and Q.sup.5 may each form a
salt such as a sulfonium salt, an oxonium salt, or a quaternary
salt. 8
[0054] In the formulae described above, R.sup.26.about.R.sup.31
represent alkyl groups and aryl groups, examples of which include
the alkyl groups and aryl groups listed as examples of R.sup.13 and
R.sup.14. Z.sup.- represents an anion. The anion may be an
inorganic anion or an organic anion. Examples of the inorganic
anion include a hexafluorophosphate ion, a hydrogenfluoride ion, a
chloride ion, a bromide ion, a hydrogensulfate ion, and so on.
Examples of the organic anion include a polyfluoroalkylsulfonate
ion, a polyfluoroalkylcarbonate ion, a tetraphenylborate ion, an
aromatic carboxylate ion, an aromatic sulfonate ion, and so on.
[0055] In the general formula (1), the ring formed by X, N, and C
is preferably a 5.about.7-membered ring and more preferably a
6-membered ring or a 7-membered ring. More preferably, Ar has the
following structure. More preferably, Cp is an acylacetanilide, a
pyrazolotriazole, a pyrazolone, a pyridone, a barbituric acid, a
pyrrolotriazole, a naphthol, a phenol, or an imidazole. Q.sup.1 in
X is more preferably --O--, --S--, --N(R.sup.22)--, --N.dbd., or a
bivalent heterocycle. Q.sup.5 is more preferably --C(.dbd.O)-- or
--SO.sub.2--. A combination of the foregoing is particularly
preferable. 9
[0056] Specific examples of the azomethine dye precursors
represented by the general formula (1) are given below. However, it
should be noted that the present invention is not limited to these
examples. 10
[0057] Next, the methods of preparing the azomethine dye precursors
represented by the general formula (1) are explained. The
azomethine dye precursors represented by the general formula (1)
can be prepared by any one of the following 3 methods.
[0058] The first method is a method wherein a compound A in which a
coupler portion and N--Ar are linked by X is prepared by oxidative
coupling (see the following reaction formula (1)).
[0059] reaction formula (1) 11
[0060] The second method is a method comprising the steps of
forming a compound B by oxidative coupling of a coupler portion
having Y and N--Ar having Z, said Y and Z, when combined, becoming
a linking group X, and thereafter linking Y and Z (i.e., conversion
into x) (see the following reaction formula (2)). 12
[0061] wherein, for example, 13
[0062] The third method is a method comprising the steps of forming
a compound C by oxidative coupling of a coupler portion having a
substituent L capable of easily leaving as an anion and N--Ar
having X and thereafter introducing X into the coupler portion (see
the following reaction formula (3)). 14
[0063] wherein, for example, L is a halogen atom (e.g., Cl, Br, or
the like) or the following formula. 15
[0064] The oxidative coupling in the above-described reaction
represented by the reaction formula (1), (2), or (3) is explained
below.
[0065] Although this oxidative coupling reaction may be performed
under any of acidic, neutral, and basic conditions, the reaction is
preferably performed under a basic condition.
[0066] Examples of the oxidizing agent include manganese peroxide,
potassium permanganate, manganese (III) acetate, potassium
hexacyanoferrate (III), chromium(VI) oxide/pyridine complex,
mercury (II) acetate, lead tetraacetate, silver (II) oxide, and so
on. Among these compounds, manganese peroxide and potassium
hexacyanoferrate (III) are preferable. The suitable amount to be
used of the oxidizing agent is 1 to 10 equivalents, preferably 1 to
5 equivalents, per equivalent of the substrate.
[0067] Examples of the base include organic bases such as
triethylamine, pyridine, and DBU, alkali metal hydrides such as
sodium hydride and potassium hydride, metal alcoholates such as
sodium methylate, sodium ethylate, and potassium butylate, alkaline
earth metal hydroxides such as calcium hydroxide and magnesium
hydroxide, alkali metal carbonates such as sodium
hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate,
and potassium carbonate, alkali metal salts of lower carboxylic
acids such as sodium formate and sodium acetate, and soon. Among
these compounds, organic bases such as triethylamine and pyridine,
and alkali metal carbonates are preferable. The suitable amount to
be used of the base is 1 to 10 equivalents per equivalent of the
substrate.
[0068] Examples of the solvent include aromatic hydrocarbons such
as benzene, toluene and xylene, chain-like or cyclic aliphatic
hydrocarbons such as pentane, hexane, heptane, and cyclohexane,
ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran,
dioxane, and ethylene glycol dimethyl ether, halogenated
hydrocarbons such as dichloroemethane and 1,2-dichloroethane,
nitrites such as acetonitrile, acetate esters such as methyl
acetate and ethyl acetate, N,N-dimethylformamide,
N,N-dimethylacetamide, dimethyl sulfoxide, acetic acid, and
mixtures of these solvents. In addition, in the case of a
water-insoluble solvent, the reaction may be performed in a
two-phase system comprising the solvent and an aqueous solution of
the base described above. The amounts to be used of these solvents
are not particularly limited.
[0069] The reaction temperature is normally selected from
temperatures ranging from room temperature to the boiling point of
the solvent, and is preferably 20 to 70.degree. C.
[0070] The reaction time is normally 0.5 to 24 hours, although it
depends on the reaction temperature.
[0071] After the completion of the reaction, the product can be
taken out by ordinary post-treatment such as extraction. Further,
if necessary, the product can be purified by a purifying means such
as silica gel column chromatography and recrystallization.
[0072] Specific examples of the synthesis of the azomethine dye
precursors represented by the general formula (1) are given
below.
[0073] (Synthesis of the azomethine dye precursor (33) of the
present invention according to the reaction formula (1)) 16
[0074] According to the reaction formula described above, 90 mL of
ethyl acetate and 46 mL of a 10% sodium carbonate aqueous solution
were added to 4.44 g (4.64 mmol) of the compound [1]. While the
resulting reaction solution was stirred, 3.21 g (9.75 mmol) of
potassium hexacyanoferrate (III) was added. After the addition, the
reaction solution was stirred for 30 minutes at room temperature.
Next, the reaction solution was separated into layers. The organic
layer was washed with water, thereafter dried, and concentrated
under a reduced pressure. An oily product thus obtained was
purified by silica gel column chromatography (eluent: ethyl
acetate/hexane=3/1). As a result, the compound (33) (3.83 g of a
yellowish solid substance in 86% yield) was obtained. The physical
properties of the compound (33) thus obtained were as follows.
[0075] [m.p.: 102.about.103.degree. C., .sup.1H-NMR (CDCl.sub.3):
8.07.about.8.18 (m, 1H) 7.25.about.7.46 (m, 1H), 7.11.about.7.25
(m, 2H), 6.96.about.7.11 (m, 1H), 6.71.about.6.89 (m, 1H),
6.55.about.6.65 (m, 2H), 6.43.about.6.51 (m, 1H), 6.30.about.6.43
(m, 1H), 6.20.about.6.23 (m, 1H), 5.80.about.5.87 (m, 1H),
5.56.about.5.72 (m, 1H), 4.56 (t, 1H), 3.56.about.3.67 (m, 1H),
3.42.about.3.56 (m, 1H), 3.40 (t, 2H), 3.32 (q, 2H), 3.21 (t, 2H),
2.95.about.3.03 (m, 1H), 2.91 (s, 3H), 2.33 (s, 3H),
2.05.about.2.18 (s, 3H), 1.82.about.1.98 (m, 5H), 1.58 (q, 2H),
1.05.about.1.40 (m, 25H), 0.85 (t, 3H), 0.56.about.0.68 (m,
6H)]
[0076] A solution of the compound (33) in ethyl acetate
(5.times.10.sup.-5 mol/L) was prepared. When 0.1 mL osurfacetic
acid was added to 2 mL of the solution described above and the
resulting solution was heated to 90.degree. C., the solution
developed a magenta color. When ethyl 6-bromocaproate was used in
place of the acetic acid and the solution was heated in the same
way, a magenta color was also developed.
[0077] The compound [I] in the reaction formula described above can
be synthesized in the following way. 17
[0078] According to the reaction formula described above, 500 mL of
DMAC was added to 60 g (0.105 mol) of the compound [2] and 171 g
(0.137 mol) of o-aminobenzenethiol. Further, 10.6 g (0.105 mol) of
triethylamine was added. After the addition, the resulting reaction
solution was stirred for 3 hours at 100.degree. C. (a gas-washing
bottle containing an antifoaming agent was connected to the
reaction vessel). After that, the reaction solution was poured into
ice water, and a yellowish solid substance which was deposited was
collected by filtration and washed with water. The substance thus
obtained was dried and thereafter recrystallized from an ethyl
acetate/hexane mixture. By this recrystallization, the compound [3]
was obtained as a white solid substance (1st: 79 g). The filtrate
was concentrated and thereafter recrystallized from an ethyl
acetate/hexane mixture. By this recrystallization, the compound [3]
was obtained as a white solid substance (2nd: 28.5 g). As a result,
the total amount of the compound [3] obtained was 107.5 g and the
yield was 78%. The physical properties of the compound [3] thus
obtained were as follows.
[0079] [m.p. : 185.about.187.degree. C., .sup.1H-NMR (CDCl.sub.3):
7.13.about.7.20 (m, 2H) 6.98.about.7.04 (m, 1H), 6.80 (dd, 1H),
6.71 (dd, 1H), 6.56.about.6.66 (m, 2H), 6.36 (d, 1H), 4.55 (t, 1H),
4.31 (brs, 2H), 3.42.about.3.70 (m, 2H), 3.08.about.3.22 (m, 1H),
2.43 (S, 3H), 1.77.about.1.90(m, 5H), 1.55 (q, 2H), 1.12.about.1.36
(m, 22H), 0.87 (t, 3H), 0.58.about.0.67 (m, 6H)]
[0080] Further, 60 mL osurfacetonitrile was added to 3.95 g (5.98
mmol) of the compound [3] obtained above and 3.04 g (7.77 mmol) of
the compound [4]. Furthermore, 0.644 g (6.57 mmol) of triethylamine
was added. After the addition, the resulting reaction solution was
stirred for 4 hours under a refluxing condition. After that, 6 mL
of 1N base was added, and the reaction solution was extracted with
ethyl acetate. Next, the organic layer was washed with water,
thereafter dried, and concentrated under a reduced pressure. An
oily product was obtained. An ethyl acetate/hexane mixture was
added to the oily product, and a solid substance that was deposited
by the addition was collected by filtration. As a result, the
compound [1] (4.24 g of a white solid substance in 74% yield) was
obtained. The physical properties of the compound [1] thus obtained
were as follows.
[0081] [m.p. : 175.about.176.degree. C., .sup.1H-NMR (CDCl.sub.3):
7.49 (d, 1H) 7.14.about.7.25 (m, 2H), 7.02.about.7.14 (m, 3H),
6.91.about.7.02 (m, 2H), 6.51.about.6.65 (m, 3H), 6.38.about.6.51
(m, 2H), 4.80 (brs, 1H), 4.42.about.4.51 (m, 1H), 3.71.about.3.82
(m, 1H), 3.50.about.3.58 (m, 1H), 3.47(t, 2H), 3.38(q, 2H), 3.39
(t, 2H), 3.01.about.3.13 (m, 1H), 2.91 (s, 3H), 2.34 (s, 3H), 2.26
(s, 3H), 1.81.about.1.89 (m, 5H) 1.56 (q, 2H), 1.06.about.1.39 (m,
25H), 0.85 (t, 3H), 0.56.about.0.68 (m, 6H)]
[0082] The compound [2] in the reaction formula described above can
be synthesized according to, for example, the method described in
JP-A No. 64-6274. The compound [4] can be synthesized in the
following way.
[0083] 10 mL of water and 30 mL of ethyl acetate were added to
4.365 g (10 mmol) of
4-amino-3-methyl-N-ethyl-N-(methanesulfonamidoethyl)aniline 1.5
sulfate-hydrate. While these materials are being stirred at room
temperature, 2.94 g (35 mmol) of sodium hydrogencarbonate was added
(since foaming was likely to occur, sodium hydrogencarbonate was
added slowly over a period of about 10 minutes). Next, while the
resulting reaction solution was cooled, 1.64 g (10.5 mmol) of
phenyl chloroformate was added dropwise (phenyl chloroformate was
added dropwise in 30 minutes while keeping the interior of the
reaction solution at 7.about.8.degree. C.). After that, the
temperature of the reaction solution was returned to room
temperature, and the reaction solution was stirred for 2 hours. The
reaction solution was then separated into layers, and the organic
layer was washed with water, thereafter dried, and concentrated
under a reduced pressure. An oily product was obtained. An ethyl
acetate/hexane mixture was added to the oily substance. The
addition caused the deposition of a solid substance, which was
collected by filtration. As a result, the compound [4] (3.6 g of a
white solid substance in 92% yield) was obtained. The physical
properties of the compound [4] thus obtained were as follows.
[0084] [m.p.: 89.about.90.degree. C., .sup.1H-NMR (CDCl.sub.3):
7.46 (brs, 1H), 7.30.about.7.40 (m, 2H), 7.15.about.7.24 (m, 3H),
6.53.about.6.64 (m, 3H), 4.74 (brs, 1H), 3.41(t, 2H), 3.34 (q, 2H),
3.26 (t, 2H), 2.89 (s, 3H), 2.31 (s, 3H), 1.12(t, 3H)]
[0085] (Synthesis of the azomethine dye precursor (33) of the
present invention according to the reaction formula (2)) 18
[0086] According to the reaction formula described above, 1 mL of
water and 50 mL of isopropanol were added to 0.2 g (3.74 mmol) of
ammonium chloride. While the resulting reaction solution was
stirred, 1.9 g (34 mmol) of reduced iron was added. Next, while the
reaction solution was vigorously stirred for 30 minutes under a
refluxing condition, 5.33 g (4.94 mmol) of the compound [5] was
added in aliquots over a period of 10 minutes. After the addition,
the reaction solution was stirred for one hour under a refluxing
condition and thereafter cooled. The reaction solution was then
filtered through celite. Water was added to the filtrate and the
resulting mixture was extracted with ethyl acetate. The organic
layer was washed with water, thereafter dried, and concentrated
under a reduced pressure. An oily product thus obtained was
purified by silica gel column chromatography (eluent: ethyl
acetate/hexane=3/1). As a result, the compound (33) of the present
invention (3.21 g of a yellowish solid substance in 68% yield) was
obtained.
[0087] A solution of the compound (33) in ethyl acetate
(5.times.10.sup.-5 mol/L) was prepared. When 0.1 mL of n-hexylamine
was added to 2 mL of the solution described above and the resulting
solution was heated to 90.degree. C., the solution developed a
magenta color. When DBU was used in place of the n-hexylamine, the
resulting solution rapidly developed a magenta color at room
temperature.
[0088] In the reaction formula described above, the compound [5]
can be synthesized by oxidative coupling between the compound [6]
and the compound (41 as shown in the following reaction formula.
19
[0089] (Synthesis of the azomethine dye precursor (33) of the
present invention according to the reaction formula (3)) 20
[0090] According to the reaction formula described above, 0.41 g (3
mmol) of potassium carbonate and 20 mL of methanol were added to
3.1 g (3 mmol) of the compound [7]. The resulting reaction solution
was stirred for 3 hours under a refluxing condition and thereafter
cooled. Water was added to the reaction solution. The resulting
mixture was neutralized with a 1N base and thereafter extracted
with ethyl acetate. The organic layer was washed with water,
thereafter dried, and concentrated under a reduced pressure. An
oily product thus obtained was purified by silica gel column
chromatography (eluent: ethyl acetate/hexane=3/1). As a result, the
compound (33) of the present invention (1.75 g of a yellowish solid
substance in 61% yield) was obtained.
[0091] A solution of the compound (33) in chloroform
(5.times.10.sup.-5 mol/L) was prepared. When 10 mg of manganese
dioxide was added to 2 mL of the solution described above, the
resulting solution rapidly developed a magenta color at room
temperature.
[0092] In the reaction formula described above, the compound [7]
can be synthesized by oxidative coupling between the compound [2]
and the following compound [8]. 21
[0093] The azomethine dye precursor of the present invention has a
property that it rapidly develops a color when it is brought into
contact with a deblocking agent at room temperature or at a
temperature falling within a range unable to cause it to develop a
color on its own by merely being heated. Because of this property,
when the azomethine dye precursor of the present invention is used
as a color-forming component of an image-forming material
comprising a support having thereon an image-forming layer, the
image-forming material develops a color well with a small amount of
energy and the storability of the image is very good.
[0094] The azomethine dye precursor represented by the general
formula (1) can be used in various recording materials. For
example, it can be used in heat-sensitive recording materials
widely utilized in such field as facsimile and printers. These
heat-sensitive recording materials utilize a coloration reaction
between an electron-donating colorless dye and an
electron-accepting compound (i.e., a color developer). In place of
the combination of the electron-donating colorless dye and the
electron-accepting compound, a combination of the dye precursor of
the present invention and a deblocking agent can be used. Besides,
examples, in which an image-forming layer comprising a combination
of the electron-donating colorless dye and the electron-accepting
compound is used in a multicolor recording layer, have been known.
Examples thereof include multicolor diazo heat-sensitive recording
materials that are to be fixed by light. These multicolor
heat-sensitive recording materials are described in JP-A Nos.
4-135787,4-144784, 4-144785,4-194842, 4-247447, 4-247448, 4-340540,
4-340541,2-34860, and so on. The combination of the dye precursor
of the present invention and a deblocking agent can be used in
these multicolor recording materials.
[0095] Further, the azomethine dye precursor represented by the
general formula (1) can also be used in silver halide
photosensitive materials. For example, a photo- and heat-sensitive
photographing material, which comprises a photosensitive silver
halide, a leuco dye reducing agent, an organosilver compound
capable of being reduced by the leuco dye reducing agent, and a
binder, has been disclosed (PCT National Publication Nos. 8-507885
and 10-502460). In this material, the dye precursor of the present
invention can be used as the leuco dye reducing agent. Furthermore,
the dye precursor of the present invention can be used as a color
former of the coloring material in the field of ordinary silver
salt photography, ink jet, and transfer materials.
[0096] [2. Image-forming Materials]
[0097] Next, the image-forming material of the present invention is
explained below. The image-forming material of the present
invention comprises a support having thereon an image-forming layer
containing at least one azomethine dye precursor of the present
invention and at least one deblocking agent. When a plurality of
image-forming layers are laminated, the deblocking agent and the
azomethine dye precursor of the present invention may be contained
in the same layer or the deblocking agent and the azomethine dye
precursor of the present invention may be contained in different
layers. By incorporating the azomethine dye precursor of the
present invention, the image-forming material of the present
invention has high sensitivity and can produce high-quality and
highly durable images speedily.
[0098] In addition, the image-forming layer in the image-forming
material may contain at least one photopolymerization initiator and
at least one polymerizable compound.
[0099] Each constituent component of the image-forming material of
the present invention is described in detail below.
[0100] A: Support
[0101] Any paper support of conventional pressure-sensitive paper,
heat-sensitive paper, and dry-process or wet-process diazo copying
paper can be used as the support for use in the image-forming
material of the present invention. Specific examples thereof
include an acidic paper, a neutral paper, a coated paper, a plastic
film-laminated paper made by laminating a plastic such as
polyethylene to paper, a synthetic paper, and a plastic film such
as a polyethylene terephthalate film and a polyethylene naphthalate
film. For the purpose of correcting the curl balance of the support
or for the purpose of preventing the penetration of chemicals from
the back of the support, a backcoat layer may be provided. The
backcoat layer may be formed in the same way as a protective layer
described later. In addition, a label form can be produced by
adhering a strip-off paper via an adhesive layer to the back of the
support. Also a so-called seal form can be produced using the
support as a strip-off paper by providing an adhesive layer on the
image-forming layer. The support may contain a fluorescent
brightener, a bluing dye, a pigment, and the like.
[0102] Furthermore, when a transparent material is used as the
support, it is also possible to write images on the support side of
the image-forming material in the optical image-forming step
described later or to irradiate the support side of the
image-forming material with light in the step in which the image is
made visible, also described later.
[0103] B: Image-forming Layer
[0104] Each constituent component of the image-forming layer and
the specific construction of the image-forming layer are explained
in detail below.
[0105] (Azomethine dye precursor)
[0106] The image-forming material may use a single kind of the
azomethine dye precursors described above so as to design a
single-color image-forming material. Alternatively, the
image-forming material may use two or more kinds of the azomethine
dye precursors described above so as to design a multicolor
image-forming material. When the multicolor image-forming material
is prepared, an azomethine dye precursor capable of developing a
hue and a dye precursor (including the azomethine dye precursors
described above) capable of developing a hue different from that of
the foregoing azomethine dye precursor can be used in combination.
That is, two or more kinds of azomethine dye precursors, each
capable of developing a different hue, can be selected from the
azomethine dye precursors represented by the general formula (1)
for use, or otherwise an azomethine dye precursor represented by
the general formula (1) can be used in combination with a
conventionally known dye precursor capable of developing a hue
different from that of the foregoing azomethine dye precursor. As
described later, a dye precursor capable of developing a hue
different from that of the azomethine dye precursor of the present
invention and the azomethine dye precursor of the present invention
may be used in the same layer. When a plurality of image-forming
layers are formed, a dye precursor capable of developing a hue
different from that of the azomethine dye precursor of the present
invention and the azomethine dye precursor of the present invention
may be used in different image-forming layers.
[0107] Examples of conventionally known dye precursors that can be
used together with the azomethine dye precursor of the present
invention include the following combinations (a) to (m) The
color-forming component A is listed first and the compound B which
reacts with the color-forming component A to cause the
color-forming component A to develop a color is listed next.
[0108] (a) a combination of a diazonium compound and a coupler;
[0109] (b) a combination of an electron-donating dye precursor and
an electron-accepting compound;
[0110] (c) a combination of a metal salt of an organic acid, such
as silver behenate or silver stearate, and a reducing agent such as
protocatechinic acid, spiroindan, or hydroquinone;
[0111] (d) a combination of an iron salt of a long-chain fatty
acid, such as ferric stearate or ferric myristate, and a phenol
such as tannic acid, gallic acid, or ammonium salicylate;
[0112] (e) a combination of a heavy metal salt of an organic acid,
such as a nickel, cobalt, lead, copper, iron, mercury, or silver
salt osurfacetic acid, stearic acid, or palmitic acid, and a
sulfide of an alkali metal or an alkaline earth metal, such as
calcium sulfide, strontium sulfide, or potassium sulfide, or a
combination of the above-described heavy metal salt of an organic
acid and an organic chelating agent such as s-diphenylcarbazide or
diphenylcarbazone;
[0113] (f) a combination of a heavy metal sulfate, such as a
silver, lead, mercury, or sodium salt of sulfuric acid, and a
sulfur compound such as sodium tetrathionate, sodium thiosulfate,
or thiourea;
[0114] (g) a combination of a ferric salt of a fatty acid, such as
ferric stearate, and an aromatic polyhydroxy compound such as
3,4-hydroxytetraphenyl methane;
[0115] (h) a combination of a metal salt of an organic acid, such
as silver oxalate or mercury oxalate, and an organic polyhydroxy
compound such as polyhydroxy alcohol, glycerin, or glycol;
[0116] (i) a combination of a ferric salt of a fatty acid, such as
ferric pelargonate or ferric laurate, and a thiocesylcarbamide or
isothiocesylcarbamide derivative;
[0117] (j) a combination of a lead salt of an organic acid, such as
lead caproate, lead pelargonate, or lead behenate, and a thiourea
derivative such as ethylenethiourea or N-dodecylthiourea;
[0118] (k) a combination of a heavy metal salt of a higher fatty
acid, such as ferric stearate or copper stearate, and zinc
dialkyldithiocarbamate;
[0119] (l) a combination capable of forming an oxazine dye such as
a combination of resorcinol and a nitroso compound; and
[0120] (m) a combination of a formazan compound and a reducing
agent and/or a metal salt.
[0121] Among the above-listed combinations, preferable are
[0122] (a) a combination of a diazonium compound and a coupler
and
[0123] (b) a combination of an electron-donating dye precursor and
an electron-accepting compound.
[0124] When an electron-donating, colorless dye precursor is used
as the color-forming component A, the dye precursor that can be
used may be a traditionally known one. Any dye precursor that
reacts with the electron-accepting compound and develops a color
can be used as the dye precursor. Specific examples of such
traditionally known dye precursors are given below. However, it
should be noted that the electron-donating, colorless dye
precursors that can used in the present invention are not limited
to these examples.
[0125] Specific examples of the electron-donating, colorless dye
precursor include a phthalide-based compound, a fluoran-based
compound, a phenothiazine-based compound, an indolylphthalide-based
compound, a leucoauramine-based compound, a rhodamine lactam-based
compound, a triphenylmethane-based compound, a triazene-based
compound, a spiropyran-based compound, a pyridine-based compound, a
pyrazine-based compound, a fluorene-based compound, and so on.
[0126] Examples of the phthalide-based compound include the
compounds described in, for example, re-issued U.S. Pat. No.
23,024, and U.S. Pat. Nos. 3,491,111, 3,491,112, 3,491,116, and
3,509,174. Specific examples thereof include
3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide,
3,3-bis(p-diethylaminophenyl)phthalide,
3-(p-dimethylaminophenyl)-3-(1,3-- dimethylindole-3-yl)phthalide,
3-(p-dimethylaminophenyl)-3-(2-methylindole- -3-yl)phthalide, and
so on.
[0127] Examples of the fluoran-based compound include the compounds
described in, for example, U.S. Pat. Nos. 3,624,107, 3,627,787,
3,641,011, 3,462,828, 3,681,390, 3,920,510, and 3,959,571. Specific
examples thereof include 2-(dibenzylamino)fluoran,
2-anilino-3-methyl-6-diethylaminofluoran,
2-anilino-3-methyl-6-dibutylami- nofluoran,
2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluoran,
2-anilino-3-methyl-6-N-methyl-N-cyclohexylaminofluoran,
2-anilino-3-chloro-6-diethylaminofluoran,
2-anilino-3-methyl-6-N-ethyl-N-- isobutylaminofluoran,
2-anilino-6-dibutylaminofluoran,
2-anilino-3-methyl-6-N-methyl-N-tetrahydrofurfurylaminofluoran,
2-anilino-3-methyl-6-piperidinoaminofluoran,
2-(o-chloroanilino)-6-diethy- laminofluoran,
2-(3,4-dichloroanilino)-6-diethylaminofluoran, and so on.
[0128] Examples of the thiazine-based compound include benzoyl
leucomethylene blue, p-nitrobenzyl leucomethylene blue, and so
on.
[0129] Examples of the leucoauramine-based compounds include
4,4'-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl
leucoauramine, N-2,4,5-trichlorophenyl leucoauramine, and so
on.
[0130] Examples of the rhodamine lactam-based compound include
rhodamine-B-anilinolactam, rhodamine-(p-nitrino)lactam, and so
on.
[0131] Examples of the spiropyran-based compound include the
compounds described in, for example, U.S. Pat. No. 3,971,808.
Specific examples thereof include 3-methyl-spiro-dinaphthopyran,
3-ethyl-spiro-dinaphthopyr- an, 3,3'
-dichloro-spiro-dinaphthopyran, 3-benzylspiro-dinaphthopyran,
3-methyl-naphto-(3-methoxybenzo) spiropyran,
3-propyl-spiro-dibenzopyran, and so on.
[0132] Examples of the pyridine-based compound and pyrazine-based
compound include the compounds described in, for example, U.S. Pat.
Nos. 3,775,424, 3,853,869, and 4,246,318.
[0133] Examples of the fluorene-based compound include the
compounds described in, for example, JP-A No. 63-094878.
[0134] As the dye precursors, which develop cyan, magenta, and
yellow colors, the dye precursors described in, for example, U.S.
Pat. No. 4,800,149 can be used.
[0135] Further, as the electron-donating dye precursors for
developing yellow colors, the dye precursors described in, for
example, U.S. Pat. Nos. 4,800,148 can also be used. As the
electron-donating dye precursors for developing cyan colors, the
dye precursors described in, for example, JP-A No. 63-53542 can
also be used.
[0136] On the other hand, examples of the electron-accepting
compound which is the compound B include traditionally known
electron-accepting compounds such as a phenol derivative, a
salicylic acid derivative, a metal salt of an aromatic carboxylic
acid, acid clay, bentonite, a novolak resin, a metal-treated
novolak resin, a metal complex, and so on. Specific examples
thereof are described in, for example, JP-B Nos. 40-9309 and
45-14039, JP-A Nos. 52-140483, 48-51510, 57-210886, 58-87089,
59-11286, 60-176795, and 61-95988.
[0137] Among the substances listed above, examples of the phenol
derivative include 2,2-bis(4-hydroxy)phenolpropane,
4-t-butylphenol, 4-phenylphenol, 4-hydroxydiphenoxide,
1,1'-bis(3-chloro-4-hydroxyphenyl)c- yclohexane, 1,1'
-bis(4-hydroxyphenyl)cyclohexane, 1,1'-bis(3-chloro-4-hyd-
roxyphenyl)-2-ethylbutane, 4,4'-sec-isooctylidenediphenol,
4,4'-sec-butylidenediphenol, 4-tert-octylphenol,
4-p-methylphenylphenol, 4,4'-methylcylcohexylidenephenol, 4,4,
-isopentylidenephenol, benzyl p-hydroxybenzoate, and so on.
[0138] Examples of the salicylic acid derivative include
4-pentadecylsalicylic acid, 3,5-di(.alpha.-methylbenzyl)salicylic
acid, 3,5-di(tert-octyl)salicylic acid, 5-octadecylsalicylic acid,
5-.alpha.-(p-.alpha.-methylbenzylphenyl)ethylsalicylic acid,
3-.alpha.-methylbenzyl-5-tert-octylsalicylic acid,
5-tetradecylsalicylic acid, 4-hexyloxysalicylic acid,
4-cyclohexyloxysalicylic acid, 4-decyloxysalicylic acid,
4-dodecyloxysalicylic acid, 4-pentadecyloxysalicylic acid,
4-octadecyloxysalicylic acid, zinc salts of these acids, aluminum
salts of these acids, calcium salts of these acids, copper salts of
these acids, lead salts of these acids, and so on.
[0139] When the image-forming layer, containing the
electron-donating dye precursor and the electron-accepting
compound, is formed, the content of the electron-donating dye
precursor in the image-forming layer is preferably 0.1 to 5
g/m.sup.2 and more preferably 0.1 to 1 g/m.sup.2. The amount to be
used of the electron-accepting compound is preferably 0.5 to 20
parts by weight, more preferably 3 to 10 parts by weight, per part
by weight of the electron-donating, colorless dye. If the amount is
less than 0.5 parts by weight, sufficient density of developed
color may not be obtained, whereas, if the amount exceeds 20 parts
by weight, sensitivity may drop or coatability may become
inferior.
[0140] When a diazonium compound is used as the color-forming
component A, it is preferable to use a compound represented by the
following formula:
Ar--N.sub.2.sup.+Y.sup.-
[0141] where Ar represents an aromatic group and Y- represents an
acid anion.
[0142] The diazonium compound is a compound which, when heated,
undergoes a coupling reaction with the coupler as the compound B to
thereby develop a color, or a compound which is decomposed by
light. It is possible to control the maximum absorption wavelength
of the compound by selecting the position or kind of the
substituent in the Ar portion.
[0143] In the general formula described above, Ar represents a
substituted or unsubstituted aryl group. Examples of the
substituent include an alkyl group, an alkoxy group, an alkylthio
group, an aryl group, an aryloxy group, an arylthio group, an acyl
group, an alkoxycarbonyl group, a carbamoyl group, a carboamide
group, a sulfonyl group, a sulfamoyl group, a sulfonamide group, a
ureido group, a halogen group, an amino group, a heterocyclic
group, and so on. These substituents may be further
substituted.
[0144] The aryl group is preferably an aryl group having 6 to 30
carbon atoms. Examples of the aryl group include a phenyl group, a
2-methylphenyl group, a 2-chlorophenyl group, a 2-methoxyphenyl
group, a 2-butoxyphenyl group, a 2-(2-ethylhexyloxy)phenyl group, a
2-octyloxyphenyl group, a 3-(2,4-di-t-pentylphenoxyethoxy)phenyl
group, a 4-chlorophenyl group, a 2,5-dichlorophenyl group, a
2,4,6-trimethylphenyl group, a 3-chlorophenyl group, a
3-methylphenyl group, a 3-methoxyphenyl group, a 3-butoxyphenyl
group, a 3-cyanophenyl group, a 3-2 ethylhexyloxy)phenyl group, a
3,4-dichlorophenyl group, a 3,5-dichlorophenyl group, a
3,4-dimethoxyphenyl group, a 3-(dibutylaminocarbonylmethoxy)phenyl
group, a 4-cyanophenyl group, a 4-methylphenyl group, a
4-methoxyphenyl group, a 4-butoxyphenyl group, a
4-(2-ethylhexyloxy)phenyl group, a 4-benzylphenyl group, a
4-aminosulfonylphenyl group, a 4-N,N-dibutylaminosulfonylphenyl
group, a 4-ethoxycarbonylphenyl group, a
4-(2-ethylhexylcarbonyl)phenyl group, a 4-fluorophenyl group, a
3-acetylphenyl group, a 2-acetylaminophenyl group, a
4-(4-chlorophenylthio)phenyl group, a 4-(4-methylphenyl)thio-2,5-
-butoxyphenyl group, a
4-(N-benzyl-N-methylamino)-2-dodecyloxycarbonylphen- yl group, and
so on.
[0145] These groups may be further substituted by an alkyloxy
group, an alkylthio group, a substituted phenyl group, a cyano
group, a substituted amino group, a halogen atom, a heterocyclic
group, and the like.
[0146] Specific examples of the diazonium forming the salt include
4-(p-tolylthio)-2,5-dibutoxybenzenediazonium,
4-((4-chlorophenylthio)-2,5- -dibutoxybenzenediazonium,
4-(N,N-dimethylamino)benzenediazonium,
4-(N,N-diethylamino)benzenediazonium,
4-(N,N-dipropylamino)benzenediazoni- um,
4-(N-methyl-N-benzylamino)benzenediazonium,
4-(N,N-dibenzylamino)benze- nediazonium,
4-(N-ethyl-N-hydroxyethylamino)benzenediazonium,
4-((N,N-diethylamino)-3-methoxybenzenediazonium,
4-(N,N-dimethylamino)-2-- methoxybenzenediazonium,
4-(N-benzoylamino)-2,5-diethoxybenzenediazonium,
4-molpholino-2,5-dibutoxybenzenediazonium,
4-anilinobenzenediazonium,
4-[N-(4-methoxybenzoyl)amino]-2,5-diethoxybenzenediazonium, 4-
pyrrolidino-3-ethylbenzenediazonium, 4-[N--
(1-methyl-2-(4-methoxyphenoxy-
)ethyl)-N-hexylamino]-2-hexyloxybenzenediazonium,
4-[N-(2-(4-methoxyphenox-
y)ethyl)-N-hexylamino]-2-hexyloxybenzenediazonium,
2-(1-ethylpropyloxy)-4--
[di-(di-n-butylaminocarbonylmethyl)amino]benzenediazonium, and so
on.
[0147] From the standpoint of effectiveness, the maximum absorption
wavelength .lambda..sub.max of the diazonium compound is preferably
450 nm or less and more preferably 290 to 440 nm. In addition, it
is desirable that the diazonium compound has 12 or more carbon
atoms and has a solubility in water of 1% or less and a solubility
in ethyl acetate of 5% or more.
[0148] The diazonium compounds may be used singly or in
combinations of two or more kinds for such purpose as adjustment of
hue.
[0149] Examples of the compound B when the diazonium compound is
used as the color-forming component A include couplers such as a
so-called active methylene compound having a methylene group
adjacent to a carbonyl group, a phenol derivative, and a naphthol
derivative. Specific examples thereof include resorcinol,
fluoroglycine, 2,3-dihydroxynaphthalene, sodium
2,3-dihydroxynaphthalene-6-sulfonate, 1-hydroxy-2-naphthoic acid
morpholinopropylamide, sodium 2-hydroxy-3-naphthalenesulfonate,
2-hydroxy-3-naphthalenesulfonic acid anilide,
2-hydroxy-3-naphthalenesulf- onic acid morpholinopropylamide,
2-hydroxy-3-naphthalenesulfonic acid-2-ethylhexyloxypropylamide,
2-hydroxy-3-naphthalenesulfonic acid-2-ethylhexylamide,
5-acetamido-1-naphthol, sodium
1-hydroxy-8-acetamidonaphthalene-3,6-disulfonate,
1-hydroxy-8-acetamidona- phthalene-3,6-disulfonic acid dianilide,
1,5-dihydroxynaphthalene, 2-hydroxy-3-naphthoic acid
morpholinopropylamide, 2-hydroxy-3-naphthoic acid octylamide,
2-hydroxy-3-naphthoic acid anilide,
5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclopentanedione,
5-(2-n-tetradecyloxyphenyl)-1,3-cyclohexanedione,
5-phenyl-4-methoxycarbo- nyl-1,3-cyclohexanedione,
5-(2,5-di-n-octyloxyphenyl)-1,3-cyclohexanedione- ,
N,N'-dicyclohexylbarbituric acid, N,N' -di-n-dodecylbarbituric
acid, N-n-octyl-N'-n-octadecylbarbituric acid,
N-phenyl-N'-(2,5-di-n-octyloxyph- enyl)barbituric acid, N,N'
-bis(octadecyloxycarbonylmethyl)barbituric acid,
1-phenyl-3-methyl-5-pyrazolone,
1-(2,4,6-trichlorophenyl)-3-anilino- -5-pyrazolone,
1-(2,4,6-trichlorophenyl)-3-benzamido-5-pyrazolone,
6-hydroxy-4-methyl-3-cyano-1-(2-ethylhexyl)-2-pyridone,
2,4-bis(benzoylacetamido)toluene,
1,3-bis(pivaloylacetamidomethyl)benzene- , benzoylacetonitrile,
thenoylacetonitrile, acetoacetanilide, benzoylacetanilide,
pivalolylacetanilide, 2-chloro-5-(N-n-butylsulfamoyl)-
-1-pivaloylacetamidobenzene,
1-(2-ethylhexyloxypropyl)-3-cyano-4-methyl-6--
hydroxy-1,2-dihydropyridine-2-one,
1-(dodecyloxypropyl)-3-acetyl-4-methyl--
6-hydroxy-1,2-dihydropyridine-2-one,
1-(4-n-octyloxyphenyl)-3-tert-butyl-5- -aminopyrazole, and so
on.
[0150] For details of the coupler compounds, reference can be made
to those described in, for example, JP-A Nos. 4-201483, 7-223367,
7-223368, 7-323660 5-278608, 5-297024, 6-18669, 6-18670, 7-316280,
9-216468, 9-216469, 9-319025, 10-035113, 10-193801, and
10-264532.
[0151] The coupler compounds undergo a coupling reaction with
diazonium compounds to form dyes in a basic environment and/or a
neutral environment. According to purposes such as color
adjustment, a number of kinds of coupler compounds can be used
together.
[0152] When an image-forming layer, containing the diazonium salt
compound and the coupler, is formed, the content of the diazonium
salt compound in the image-forming layer is preferably 0.01 to 3
g/m.sup.2 and more preferably 0.02 to 1.0 g/m.sup.2. If the content
is less than 0.01 g/m.sup.2, sufficient density of developed color
is not obtained, whereas, if the content exceeds 3 g/m.sup.2,
coatability of the coating liquid becomes inferior. The amount to
be used of the coupler compound is preferably 0.5 to 20 parts by
weight, more preferably 1 to 10 parts by weight, per part by weight
of the diazonium salt compound. If the amount is less than 0.5
parts by weight, sufficient color developability is not obtained,
whereas, if the amount exceeds 20 parts by weight, coatability
becomes undesirably inferior.
[0153] (Deblocking agent)
[0154] Preferably, the deblocking agent is at least one selected
from an acid, a base, an oxidizing agent, an alkylating agent, and
a metal salt.
[0155] Acid
[0156] A wide range of compounds having an active hydrogen can be
used as the acid. The term "acid, as used herein refers an acid in
a broad sense and thus includes a Lewis acid as well. Preferable as
the acids are organic acids such as aliphatic carboxylic acids,
aromatic carboxylic acids, sulfonic acids, phenols, naphthols,
carbonamides, sulfoneamides, ureas, thioureas, and active methylene
compounds.
[0157] Specific examples of these organic acids include aliphatic
carboxylic acids such as behenic acid, stearic acid, oleic acid,
lauric acid, caproic acid, myristic acid, maleic acid, fumaric
acid, palmitic acid, tartaric acid, linoleic acid, levulinic acid,
4-acetylbutyric acid, 7-oxooctanoic acid, monoethyl maleate,
mono-2-ethylhexyl maleate, monoethyl fumarate, and
o-methoxycinnamic acid, aromatic carboxylic acids such as benzoic
acid, 4-octylbenzoic acid, 4-dodecyloxybenzoic acid, phthalic acid,
mono-2-ethylhexyl phthalate, 3-chloro-4-hydroxybenzoic acid,
salicylic acid, 4-pentadecylsalicylic acid,
4-methoxycarbonylaminos- alicylic acid,
4-n-octyloxycarbonylaminosalicylic acid,
3,5-di(.alpha.-methylbenzyl)salicylic acid,
3,5-di(tert-octyl)salicylic acid, and 5-octadecylsalicylic acid,
sulfonic acids such as ethanesulfonic acid and
4-dodecylbenzenesulfonic acid, phenols such as 3-pentadecylphenol,
4-t-butylphenol, 2,2'-bis (4-hydroxyphenyl)propane, benzyl
p-hydroxybenzoate, 2-ethylhexyl p-hydroxybenzoate, and 2-ethylhexyl
3-chloro-4-hydroxybenzoate, octadecaneamide,
N-butylbenzenesulfonamide, 4-(isoamyloxy)benzenesulfonamide,
4-(2-ethylhexyl)-N-acetylsulfonamide, N-octadecylurea,
N-phenyl-N'-octylurea, N-(2-ethylhexyl)-N'-(p-toluenesulfonyl)urea,
1-benzyl-3-methyl-2-thiourea, n-octyl cyanoacetate, Meldrum's acid,
and so on. These acids may be used singly or in combinations of two
or more kinds.
[0158] Base
[0159] Preferably, the bases are organic bases, such as primary to
tertiary amines, piperizines, piperazines, amidines, formamidines,
pyridines, guanidines, and morpholines. A base precursor that
develops the base can also be used as the base. The term "base" as
used herein means a base in a broad sense and includes a
nucleophilic agent (a Lewis base) in addition to a base in a narrow
sense.
[0160] Specific examples of the organic base include piperazines
such as N,N'-bis(3-phenoxy-2-hydroxypropyl)piperazine, N,N'-bis
[3-(p-methylphenoxy)-2-hydroxypropyl]piperazine, N,N'-bis
[3-(p-methoxyphenoxy)-2-hydroxypropyl]piperazine,
N,N'-bis(3-phenylthio-2- -hydroxypropyl)piperazine, N,N'-bis
[3-(-naphthoxy)-2-hydroxypropyl]pipera- zine,
N-3-(-naphthoxy)-2-hydroxypropyl-N'-methylpiperazine, and 1,4-bis
{[3-(N-methylpiperazino)-2-hydroxy]propyloxy}benzene, morpholines
such as N-[3-(.beta.-naphthoxy)-2-hydroxy]propylmorpholine, 1,4-bis
[(3-morpholino-2-hydroxy)propyloxy]benzene, and 1,3-bis
[(3-morpholino-2-hydroxy)propyloxy]benzene, piperidines such as N--
(3-phenoxy-2-hydroxypropyl)piperidine and N-dodecylpiperidine,
triphenylguanidine, tricyclohexylguanidine, dicyclohexylguanidine,
4-hydroxybenzoic acid 2-N-methyl-N-benzylaminoethyl ester,
4-hydroxybenzoic acid 2-N,N-di-n-butylaminoethyl ester,
4-(3-N,N-dibutylaminopropoxy)benzenesulfonamide,
4-(2-N,N-dibutylaminoeth- oxycarbonyl)phenoxyacetic acid amide,
trioctylamine, octadecylamine, N-methyl-N-octadecylamine, and so
on. These organic bases may be used singly or in combinations of
two or more kinds.
[0161] These organic bases are described in, for example, JP-A Nos.
57-123086, 60-49991, 60-94381, 09-071048, 09-077729, and
09-077737.
[0162] The term "base precursor" as used herein means a compound
that releases a base when heated and includes a salt of a base and
an organic acid. The base that constitutes the base precursor is
preferably selected from those listed as examples of the bases
described previously. General Bronsted acid and Lewis acid can be
used as the organic acids. In addition, a carboxylic acid that
releases a base by a decarboxylation reaction can also be used. In
this sense, such acids as sulfonylacetic acid and propiolic acid
are preferable because these acids easily cause a decarboxylation
reaction. Furthermore, sulfonylacetic acid and propiolic acid,
which have an aromatic substituent (such as an aryl or heterocyclic
group), are preferable because the decarboxylation reaction is
further accelerated. The sulfonylacetic acid salts as base
precursors are described more specifically in JP-A No. 59-168441.
The propiolic acid as a base precursor is described more
specifically in JP-A No. 59-180539.
[0163] Examples of diacidic precursors capable of releasing amidine
or guanidine are shown below. However, it should be noted that the
base precursors, which become the deblocking agents in the present
invention, are not limited to these examples. 22
[0164] Oxidizing Agent
[0165] Examples of the oxidizing agent include quinones such as
2,3-dichloro-5,6-dicyano-1,4-benzoquinone and
tetrachloro-1,4-benzoquinon- e, nitro compounds such as
nitrobenzene and m-nitrobenzenesulfonic acid, nitroso compounds
such as nitrosobenzene, cations such as triphenylcation, azo
compounds such as diethyl azodicarboxylate, nitroxides such as
diphenyl nitroxide, porphyrioxide, and
2,2,6,6-tetramethylpiperidine-1-oxyl, N-oxides such as
pyridine-N-oxide, peroxides such as sodium perchlorate, potassium
periodate, and m-chloroperbenzoate, halogens such as bromine and
iodine, hypochlorites such as sodium hypochlorite, metal oxides
such as manganese dioxide, and so on. These oxidizing agents may be
used singly or in combinations of two or more kinds.
[0166] Alkylating Agent
[0167] Examples of the alkylating agent include alkyl halides such
as alkyl iodide and alkyl bromide, sulfuric acid alkyl esters, and
sulfonic acid esters.
[0168] The alkyl group may have a substituent. Examples of the
substituent include an alkoxycarbonyl group, an aryloxycarbonyl
group, a carbamoyl group, a sulfonyl group, a sulfamoyl group, an
acyl group, and so on.
[0169] Specific examples of the alkylating agent include
1-iodooctane, 1-iodononane, 1-iododecane, 1-iodoundecane,
1-iodododecane, 1-iodohexadecane, n-decyl bromoacetate, n-dodecyl
bromoacetate, n-octadecyl bromoacetate, bromoacetic acid
N,N-di-n-butylamide, n-octyl 3-bromopropionate, n-hexadecyl
4-bromobutyrate, 2-(2,5-di-t-amylphenyloxy- )ethyl 4-bromobutyrate,
2-(2,5-di-t-amylphenyloxy)ethyl 5-bromovalerate, 6-bromocaproic
acid N,N-di-n-butylamide, 6-bromocaproic acid N,N-di-n-hexylamide,
dibutyl sulfate, diamyl sulfate, dihexyl sulfate, dioctyl sulfate,
n-hexyl p-toluenesulfonate, n-octyl p-toluenesulfonate, n-octadecyl
p-toluenesulfonate, n-octadecyl methanesulfonate, and so on. These
alkylating agents may be used singly or in combinations of two or
more kinds.
[0170] Metal Salt
[0171] Examples of the metal salt include metal salts of compounds
having amercapto group, a thionyl group, or an imino group besides
metal salts of the aliphatic carboxylic acids listed as acids and
metal salts of aromatic carboxylic acids listed as acids.
[0172] Specific examples of these acids include
2-mercaptobenzimidazole, 2-mercaptobenzoxazole,
2-mercapto-5-aminothiazole, thioamide,
5-carboxy-1-methyl-2-phenyl-4-thiopyridine, mercaptotriazine,
3-(2-carboxyethyl)-4-methyl-(4-thiazoline)-2-thione, benzotriazole,
1,2,4-triazole, 1H-tetrazole, imidazole, and so on.
[0173] Examples of the metal atom include monovalent metals such as
sodium, potassium, lithium, and silver, and polyvalent metals such
as zinc, magnesium, barium, calcium, aluminum, tin, titanium,
nickel, cobalt, manganese, and iron. In particular, silver, zinc,
aluminum, magnesium, and calcium are preferable.
[0174] Specific examples of the metal salts include silver
behenate, silver stearate, zinc
3,5-di(.alpha.-methylbenzyl)salicylate, zinc
4-n-octyloxycarbonylaminosalicylate, silver salt of
2-mercaptobenzimidazole, silver salt of 5-chlorobenzotriazole, and
so on. The metal salts may be used singly or may be used in
combinations of two or more kinds.
[0175] The deblocking agent may have a polymerizable group and may
act as a polymerizable compound simultaneously. Specific examples
of such deblocking agents are listed hereinafter in the paragraph
on "polymerizable compounds".
[0176] The content (in moles) of the deblocking agent is preferably
0.1 to 100 times, more preferably 0.5 to 30 times, the content (in
moles) of the azomethine dye precursor described later. However, it
should be noted that the content is not limited to the content
described above because a preferable content range of the
deblocking agent varies depending on the azomethine dye precursor
with which it is used.
[0177] (Photopolymerization initiator)
[0178] The photopolymerization initiator to be used may be a
conventionallyknownone. Photopolymerizationinitiatoris, for
example, a benzophenone derivative or an acetophenone derivative.
Specific examples of the photopolymerization initiator include
.alpha.-hydroxy- or .alpha.-aminoacetophenone,
4-aroyl-1,3-dioxolane, benzoyl alkyl ether and benzylketal,
monoacylphosphine oxide, bisacylphosphine oxide or titanocene,
fluoroscein, anthraquinone, thioxanthone, xanthone, and so on. The
photopolymerization initiator is preferably a combination of a dye
and a radical generator capable of interacting with the dye to
thereby generate a radical. This is because, when irradiated with
light, the combination can generate a radical in the exposed
portion locally and in an effective way, and can also provide a
high level of sensitivity.
[0179] Examples of the radical generator include aromatic ketones
such as benzophenone, 4,4-bis(dimethylamino)benzophenone,
4-methoxy-4' -dimethylaminobenzophenone, 4,4,
-dimethoxybenzophenone, 4-dimethylaminobenzophenone,
4-dimethylaminoacetophenone, benzylanthraquinone,
2-tert-butylanthraquinone, 2-methylanthraquinone, xanthone,
thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone,
fluorenone, acridone, (bis)acylphosphine oxides, e.g.,
bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; benzoin and
benzoin ethers such as benzoin methyl ether, benzoin ethyl ether,
benzoin isopropyl ether, and benzoin phenyl ether; dimers of
2,4,6-triarylimidazole such as a diner of
2-(o-chlorophenyl)-4,5-diphenyl- imidazole, a dimer of
2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole, a dimer of
2-(o-fluorophenyl)-4,5-diphenylimidazole, a dimer of
2-(o-methoxyphenyl)-4,5-diphenylimidazole, and a dimer of
2-(p-methoxyphenyl)-4,5-diphenylimidazole; polyhalogen compounds
such as carbon tetrabromide, phenyltribromomethylsulfone, and
phenyltrichloromethyl ketone; compounds described in JP-A Nos.
59-133428, JP-B No. 57-1819, JP-B No. 57-6096, and U.S. Pat. No.
3,615,455; S-triazine derivatives having a trihalogen-substituted
methyl group described in JP-A No. 58-29803 such as
2,4,6-tris(trichloromethyl)-S-tria- zine,
2-methoxy-4,6-bis(trichloromethyl)-S-triazine,
2-amino-4,6-bis(trichloromethyl)-S-triazine, and
2-(p-methoxystyryl)-4,6-- bis(trichloromethyl)-S-triazine; organic
peroxides described in JP-A No. 59-189340 such as methyl ethyl
ketone peroxide, cyclohexanone peroxide,
3,3,5-trimethylcyclohexanone peroxide, benzoyl peroxide, di-t-butyl
diperoxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane,
t-butyl peroxybenzoate, a,a'-bis(t-butylperoxyisopropyl)benzene,
dicumylperoxide, and 3,3',
4,4'-tetra-(t-butylperoxycarbonyl)benzophenone; azinium salts
described in U.S. Pat. No. 4,743,530; organoboron compounds
described in European Patent No. 0,223,587 such as
tetramethylammonium salt of triphenylbutylborate,
tetrabutylammonium salt of triphenylbutylborate, and
tetramethylammonium salt of tri(p-methoxyphenyl)butylborate;
diaryliodonium salts; and iron allene complexes.
[0180] In addition, a combination of two or more radical generators
can also be used. Examples of the combination include a combination
of a dimer of 2,4,5-triarylimidazole and mercaptobenzoxazole or the
like, a combination of 4,4'-bis(dimethylamino)benzophenone and
benzophenone or benzoin methyl ether described in U.S. Pat. No.
3,427,161, a combination of benzoyl-N-methylnaphtothiazoline and
2,4-bis(trichloromethyl)-6-(4'-me- thoxyphenyl)-triazole described
in U.S. Pat. No. 4,239,850, a combination of a dialkylaminobenzoate
ester and dimethylthioxanthone described in JP-A No. 57-23602, a
combination made up of 3 kinds of compounds, i.e.,
4,4'-bis(dimethylamino)benzophenone, benzophenone, and a
polyhalogenated-methyl compound described in JP-A No. 59-78339.
[0181] Preferable as the radical generators are organoboron
compounds, benzoin ethers, S-triazine derivatives having a
trihalogen-substituted methyl group, organic peroxides,
(bis)acylphosphine oxides, lophine dimers, titanocenes, and azinium
salt compounds because, when irradiated with light, these radical
generators can generate a radical locally in the exposed portion in
an effective way and can provide a high level of sensitivity. In
particular, organoboron compounds are preferable from the
standpoint of sensitive wavelength and radical generation
efficiency.
[0182] Examples of the organoboron compounds include the
organoboron compounds described in JP-A Nos. 62-143044, 9-188685,
9-188686, 9-188710, 11-269210, etc., and spectral sensitizing
dye-based organoboron compounds obtainable from cationic dyes.
Organoboron compounds represented by the following general formula
(2) are preferable. 23
[0183] In the general formula (2), R.sup.1.about.R.sup.4 each
represents an alkyl group, an aryl group, a heterocyclic group, or
SiR.sup.5R.sup.6R.sup.7. R.sup.5, R.sup.6, and R.sup.7 each
represents an alkyl group or an aryl group, while G.sup.+
represents a group capable of forming a cation.
[0184] In the general formula (2), it is preferable that at least
one of R.sup.1.about.R.sup.4 is an alkyl group. Further, from the
standpoint of sensitivity and storability, it is preferable that
the general formula (2) has a triarylalkyl borate skeleton.
[0185] Furthermore, it is also preferable that a plurality of
photopolymerization initiators composed of an organoboron compound
and a dye and/or other kinds of photopolymerization initiators are
used in combination such that sensitive wavelengths vary.
[0186] The organoboron compound represented by the general formula
(2) is explained in detail below.
[0187] In the general formula (2), the alkyl group of
R.sup.1.about.R.sup.4 is preferably an alkyl group having 1 to 18
carbon atoms, and more preferably an alkyl group having 1 to 12
carbon atoms. The alkyl group may have an unsaturated bond. The
alkyl group may be a straight-chain alkyl group or may be a
branched alkyl group.
[0188] In the general formula (2), the aryl group of
R.sup.1.about.R.sup.4 is preferably an aryl group having 6 to 26
carbon atoms, and more preferably a phenyl group or a naphthyl
group.
[0189] These alkyl groups and aryl groups may have substituents.
Examples of the substituents include an alkyl group, an aryl group,
an alkoxy group, an aryloxy group, an alkylthio group, an arylthio
group, a halogen atom, an alkoxycarbonyl group, an aryloxycarbonyl
group, an acyloxy group, CN, and NO.sub.2.
[0190] In the general formula (2), examples of the heterocyclic
group include heterocyclic groups having such rings as furan,
thiophene, pyrrole, imidazole, pyrazole, triazole, pyridine, and
pyrimidine rings.
[0191] In the general formula (2), examples of
SiR.sup.5R.sup.6R.sup.7 include trimethylsilyl, triphenylsilyl,
dimethylphenylsilyl, di-t-butylphenylsilyl, and so on.
[0192] In the general formula (2), G.sup.+ is a group capable of
forming a cation, as stated previously. This group is, for example,
an alkali metal (particularly lithium or sodium), an alkaline earth
metal, a transition metal, a quaternary ammonium, a dye cation, or
a cationic coordinate complex compound of transition metal.
Preferably, this group is ammonium, a tetraalkylammonium, or a dye
cation. The tetraalkylammonium is represented by the following
formula: 24
[0193] In the formula described above, R.sup.74-R.sup.77 each
represents an alkyl group. Accordingly, examples of the
tetraalkylammonium include tetramethylammonium in which
R.sup.74.about.R.sup.77 are methyl groups, tetraethylammonium in
which R.sup.74-R.sup.77 are ethyl groups, tetrapropylammonium in
which R.sup.74.about.R.sup.77 are propyl groups, and
tetrabutylammonium in which R.sup.74.about.R.sup.77 are butyl
groups.
[0194] In the formula described above, G.sup.+ is also preferably a
benzyltrialkylammonium represented by the following formula: 25
[0195] In the formula described above, R.sup.78.about.R.sup.80 each
represents an alkyl group. Preferable examples of the
benzyltrialkylammonium include benzyltrimethylammonium,
benzyltriethylammonium, benzyltripropylammonium, and
benzyltributylammonium.
[0196] Also preferable is a trisalkylammonium ion, for example,
trimethylammonium ion. Besides, G.sup.+ may be a phosphonium ion or
ammonium ion indicated below. 26
[0197] In the general formula described above, R.sub.w, R.sub.x,
R.sub.y, and R.sub.z each independently represents a hydrogen atom,
a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, phenyl,
or arylalkyl group. Specific examples of the substituents of these
alkyl, cycloalkyl, alkenyl, phenyl, and arylalkyl groups include a
halogen atom, a hydroxyl group, a heterocycloalkyl group (such as
an epoxy group, an aziridyl group, an oxetanyl group, a furanyl
group, a pyrrolidinyl group, a pyrrolyl group, a thiophenyl group,
and a tetrahydrofuranyl group), a dialkylamino group, an amino
group, a carboxyl group, an alkylcarbonyl or arylcarbonyl group, an
aryloxycarbonyl or alkoxycarbonyl group. The quadrivalent nitrogen
atom may be part of a 5- or 6-membered ring, and other ring may be
fused with the ring. These rings may contain other heteroatom such
as S, N, or O.
[0198] Further, G.sup.+ may be a polyammonium or polyphosphonium
ion which is a poly-ion structure of the above-described ammonium
or phosphonium ion. A bis-structure is particularly preferable as
the poly-ion. Where the poly-ion has a substituent, examples of the
substituent are the same as those listed as the substituents of the
mono-ions described above.
[0199] The above-described ammonium ion and phosphonium ion may be
substituted by a neutral dye (such as thioxanthene, thioxanthone,
coumarin, or ketocoumarin). These ions are obtained by the reaction
between an ammonium or phosphonium ion having a reactive
substituent (such as an epoxy group, an amino group, or a hydroxyl
group) and a suitable neutral dye. For example, reference may be
made to Quantacure QTX described in EP-A-224967.
[0200] Likewise, the ammonium ion and phosphonium ion can be
substituted by a colorless, electron-accepting substance (such as
benzophenone). Examples of G.sup.+, in which an ammonium ion is
substituted by benzophenone, are given below. However, it should be
noted that the present invention is not limited to these examples.
27
[0201] Examples of the quaternary ammonium ion include a
trimethylcetylammonium ion and a cetylpyridinium ion.
[0202] Other examples of G.sup.+ are the cations included in the
cation group 1 indicated below. 28
[0203] In the formulae described above, Z represents P, S, or N,
and R represents an alkyl group or an aryl group.
[0204] Yet other examples of G.sup.+ are the cations included in
the cation group 2 or cation group 3 indicated below. In the
formulae of the cation group 2 described below, R represents an
alkyl group or an aryl group. These cations are described in
Yaguchi, et al., J. Polym. Sci. Part A: Polymer Chem. 1992, 30,
1987 and Polymer, 1993, 34(6), 1130. In the formulae of the cation
group 3, R' represents an unsubstituted or substituted benzyl or
phenacyl group. These cations are disclosed in JP-A No. 7-770221.
The aromatic ring in the pyrimidinium portion of these cations may
have a substituent. 29
[0205] Other cationic counter ion G.sup.+ may be other onium ion
such as an iodonium ion or a sulfonium ion. These cations are
disclosed in, for example, EP-A-555058 and EP-A-690074. Some
examples thereof include the cations represented by the following
formula: 30
[0206] The cations indicated below are also desirable as G.sup.+.
31
[0207] Still other examples of G.sup.+ are the cations indicated
below. In the formulae described below, R.sub.g represents an alkyl
group, an ethyl group in particular, or a benzyl group. The
aromatic ring may have a substituent. 32
[0208] G.sup.+ may be a halonium ion. Particularly preferable as
the halonium ions are the diaryliodonium ions disclosed in, for
example, EP-A-334056 and EP-A-562897.
[0209] Also preferable are the ferrocenium cations represented by
the following formula and described in EP-A-94915 and EP-A-109851.
33
[0210] G.sup.+ may be an onium ion disclosed in JP-A No. 6-266102
such as an ammonium ion, a phosphonium ion, sulfonium ion, an
iodonium ion, a selonium ion, an arsonium ion, a tellonium ion, and
a bismuthonium ion.
[0211] G.sup.+ may be a cationic complex compound of transition
metal. Specific examples thereof include the cationic complex
compounds of transition metals described in U.S. Pat. No.
4,954,414. Particularly preferable are bis(2,2'-bipyridine)
(4,4'-dimethyl-2,21-bipyridine)ruthen- ium,
tris(4,4'-dimethyl-2,2'-bipyridine)ruthenium,
tris(4,4'-dimethyl-2,2'- -bipyridine)iron, tris(2,2', 2"
-terpyridine)ruthenium, tris(2,2'-bipyridine)ruthenium, and
bis(2,2'-bipyridine)(5-chloro-1,10-ph- enanthrene)ruthenium.
[0212] G.sup.+ may be a cationic dye. Specific examples thereof
include cationic dyes such as cyanine dyes and cationic dyes of
triarylmethane.
[0213] The organoboron compounds described in the general formula
(2) can be used in combinations with conventionally known
photopolymerization initiators such as benzophenone or acetophenone
derivatives, e.g., .alpha.-hydroxy- or .alpha.-aminoacetophenone,
4-aroyl-1,3-dioxolane, benzoin alkyl ether and benzylketal,
monoacylphosphine oxide, bisacylphosphine oxide, titanocene,
fluorescein, anthraquinone, thioxanthone, or xanthone. Particularly
suitable photopolymerization initiators are
1-(4-dodecylbenzoyl)-1-hydroxy-1-methylethane,
1-(4-isopropylbenzoyl)-1-hydroxy-1-methylethane,
1-benzoyl-1-hydroxy-1-me- thylethane,
1-[4(2-hydroxyethoxy)-benzoyl]-1-hydroxy-1-methylethane,
1-[4(acryloyloxyethoxy)-benzoyl]-1-hydroxy-1-methylethane,
diphenylketone, phenyl-1-hydroxy-cyclohexylketone,
(4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane,
1-(3,4-dimethoxyphenyl)-2-benzyl-2-dimethylamino-butane-1-one,
(4-methylthyrobenzoyl)-1-methyl-1-morpholino-ethane,
benzyldimethylketal,
bis(cyclopentadienyl)-bis(2,6-difluoro-3-pyryl-phenyl)titan,
cyclopentadienyl-allene-iron(II) complexsalt, e.g.,
(.eta..sup.6-isopropylbenzene)-(.eta..sup.5-cyclopentadienyl)iron(II)hexa-
fluorophosphate, trimethylbenzoyldiphenylphosphine oxide,
bis(2,6-dimethoxybenzoyl)-(2,4,4-trimethylpentyl)-phosphine oxide,
bis(2,4,6-trimethylbenzoyl)-2,4- dipentyloxyphenyl-phosphine oxide,
or bis(2,4,6-trimethylbenzoyl)phenyl-phosphine oxide.
[0214] Other suitable additional photopolymerization initiators can
be found in U.S. Pat. No. 4,950,581, column 20, line 35, to column
21, line 35. Also suitable are triazine compounds, for example, the
triazines described in EP-A-137452, DE-A-2718254, and DE-A-2243621.
Other suitable triazines are found in U.S. Pat. No. 4,950,581,
column 14, line 60, to column 18, line 44. Among
trihalomethyltriazines, particularly interesting is, for example,
2,4-bis(trichloromethyl)-6-(4-styrylphenyl)-- s-triazine. When this
novel photopolymerization initiator (c) is used in a hybrid system,
a cationic photopolymerization initiator such as a peroxide
compound, e.g., benzoyl peroxide (other suitable peroxides are
described in U.S. Pat. No. 4,950,581, column 19, lines
17.about.25), an aromatic sulfonium or iodonium salt, or
cyclopentadienyl-allene-iron(II) complex salt such as
(.eta..sup.6-isopropylbenzene)-(.eta..sup.5-cyclopen-
tadienyl)-iron(II)hexafluorophosphate described in U.S. Pat. No.
4,950,581, column 18, line 60, to column 19, line 10, is used in
addition to the novel free radical hardener.
[0215] The dye, which is combined with the radical generator, may
be any dye selected from a cationic dye, an anionic dye, and a
nonionic dye, and is preferably a dye having a maximum absorption
wavelength falling within a range of 300 to 1000 nm. By selecting
any desired dye from the so-called spectral sensitizing dyes within
the wavelength range described above and using the dye for the
purpose of adjusting the sensitive wavelength so that the sensitive
wavelength matches the light source to be used, it becomes possible
to obtain an image-forming material having a high sensitivity.
Also, it becomes possible to suitably select a light source such as
blue, green, or red light, or otherwise an infrared laser or the
like.
[0216] As a result, for example when a color image is formed using
an image-forming material, which is of a multicolor photo- and
heat-sensitive recording type and has an image-forming layer made
by laminating single-color image forming layers capable of
developing different hues, the multicolor image-forming material as
a whole can provide a high sensitivity and a high level of image
sharpness, because, even though the image-forming material has a
laminate construction, each layer (each color) can have a high
sensitivity and form highly sharp images by the incorporation of
spectral sensitizing dyes having different absorption wavelengths
in the single-color image forming layers capable of developing
different hues and by the use of light sources suited to the
absorption wavelengths.
[0217] When the image-forming material of the present invention is
used as photo- and pressure-sensitive paper, the paper may have the
laminate construction described above, or alternatively, spectral
sensitizers, organoboron compounds, dye precursors, and the like
may be incorporated in the same layer so that multicolor
development becomes possible. More specific layer construction of
the image-forming layer is described later.
[0218] Examples of the spectral sensitizing dye include
conventionally known keto dyes such as coumarin dyes (including
ketocoumarin and sulfonocoumarin), merostyryl dyes, oxonol dyes,
and hemioxonol dyes; nonketo dyes such as ketopolymethine dyes,
triarylmethane dyes, xanthene dyes, anthracene dyes, rhodamine
dyes, acridine dyes, aniline dyes, and azo dyes; nonketopolymethine
dyes such as azomethine dyes, cyanine dyes, carbocyanine dyes,
dicarbocyanine dyes, tricarbocyanine dyes, hemicyanine dyes, and
styryl dyes; quinoneimine dyes such as azine dyes, oxazine dyes,
thiazine dyes, quinoline dyes, and thiazole dyes; and so on. More
specific examples include spectral sensitizing dyes described in,
for example, JP-A No. 62-143044, JP-A No. 3-20260, JP-A No.
1-84245, JP-A No. 1-138204, JP-A No. 1-100536, JP-A No. 9-188686,
and PCT National Publication No. 6-505287.
[0219] The dye/organoboron compound ratio is preferably 1/0.1 to
1/100 and more preferably 1/0.5 to 1/10.
[0220] (Polymerizable compound)
[0221] The polymerizable compound is a compound having in the
chemical structure thereof at least one ethylenically unsaturated
bond. Besides monomers, the polymerizable compounds include
prepolymers, that is, dimers of the monomers, trimers of the
monomers, oligomers of the monomers, mixtures thereof, copolymers
thereof, and so on. Examples of these compounds include unsaturated
carboxylic acids and salts thereof, esters thereof with aliphatic
polyhydric alcohols, amides thereof with aliphatic polyvalent
amines, styrene, vinyl ethers, vinyl esters, N-vinyl heterocycles,
allyl ethers, allyl esters, and so on.
[0222] Specific examples of the unsaturated carboxylic acids
include acrylic acid, methacrylic acid, itaconic acid, crotonic
acid, isocrotonic acid, maleic acid, and so on. Examples of the
salts of the unsaturated carboxylic acids include sodium salts and
potassium salts of the carboxylic acids described above.
[0223] The polymerizable compound may contain one or more olefinic
double bonds and may be any of a low molecular weight compound
(i.e., monomeric compound) and a high molecular -weight compound
(i.e., oligomeric compound). Examples of the monomer containing a
double bond are alkyl or hydroxyalkyl acrylates or methacrylates
such as methyl acrylate, ethyl acrylate, butyl acrylate,
2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, isobornyl acrylate,
methyl methacrylate, or ethyl methacrylate. In addition, silicone
acrylates are advantageous. Other examples are acrylonitrile,
acrylamide, methacrylamide, N-substituted (meth)acrylamide, vinyl
esters such as vinyl acetate, vinyl ethers such as isobutyl vinyl
ether, styrene, alkyl- and halo-styrene, N-vinylpyrrolidone, vinyl
chloride, or vinylidene chloride.
[0224] Examples of the monomer containing two or more double bonds
are a diacrylate of ethylene glycol, propylene glycol, neopentyl
glycol, hexamethylene glycol, or bisphenol A,
4,4'-bis(2-acryloyloxyethoxy)diphen- ylpropane, trimethylolpropane
triacrylate, pentaerythritol triacrylate or tetraacrylate, vinyl
acrylate, divinylbenzene, divinyl succinate, diallyl phthalate,
triallyl phosphate, and triallyl isocyanurate or tris
(2-acryloylethyl) isocyanurate.
[0225] Examples of multi-unsaturated compound having a relatively
high molecular weight (i.e., oligomeric compound) include
acrylisized epoxy resins, acrylisized polyesters, polyesters
containing a vinyl ether or epoxy group, polyurethanes, and
polyethers. Further examples of the unsaturated oligomer are
unsaturated polyester resins which are produced normally from
maleic acid, phthalic acid, and one or more diols and which have a
molecular weight of about 500 to 3000. In addition, it is also
possible to use vinyl ether monomers and oligomers, and/or
oligomers which have polyester, polyurethane, polyether, polyvinyl
ether, or epoxy main chains and are endstopped with maleate.
Particularly suitable is a combination of an oligomer having a
vinyl ether group and a polymer described in WO90/01512. Also
suitable is a copolymer of a vinyl ether and a maleic
acid-functionalized monomer. These oligomers may also belong to
prepolymers.
[0226] Particularly suitable examples are an ester of an
ethylenically unsaturated carboxylic acid and a polyol or a
polyepoxide, a polymer having in the main or side chain thereof an
ethylenically unsaturated group such as an unsaturated polyester,
polyamide, and polyurethane as well as a copolymer thereof, an
alkyd resin, a polybutadiene and a butadiene copolymer, a
polyisoprene and an isoprene copolymer, a polymer and copolymer
having in the side chain thereof a (meth)acryl group, and a mixture
of one or more of these polymers.
[0227] Examples of the unsaturated carboxylic acid are unsaturated
fatty acids such as acrylic acid, methacrylic acid, crotonic acid,
itaconic acid, cinnamic acid, linoleic acid, or oleic acid. Among
these acids, acrylic acid and methacrylic acid are preferable.
[0228] Aromatic polyols, and aliphatic and alicyclic polyols in
particular, are suitable as the polyol. Examples of the aromatic
polyols are hydroquinone, 4,4'-dihydroxydiphenyl, 2,2-di
(4-hydroxydiphenyl)propa- ne, and/or novolak, and resol. Examples
of the polyepoxides are those based on polyols, aromatic polyols in
particular, and those based on epichlorohydrin. Examples of other
suitable polyols are polymers and copolymers having in the polymer
chain or side chain thereof a hydroxyl group such as polyvinyl
alcohol or copolymers thereof, or polyhydroxyalkyl methacrylate or
copolymers thereof. In addition, an oligoester having a hydroxyl
terminal group is also suitable as the polyol.
[0229] Examples of the aliphatic and alicyclic polyols are
preferably alkylene diols having 2 to 12 carbon atoms such as
ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3-, or
1,4-butanediol, pentanediol, hexanediol, octanediol, dodecanediol,
diethylene glycol, triethylene glycol, polyethylene glycol
preferably having a molecular weight of 200 to 1500,
1,3-cyclopentanediol, 1,2-, 1,3-, or 1,4-cyclohexanediol,
1,4-dihydroxymethylcyclohexane, glycerol,
tris(.beta.-hydroxyethyl)amine, trimethylolethane,
trimethylolpropane, pentaerythritol, dipentaerythritol, and
sorbitol.
[0230] The polyol can be partially or completely esterified by one
unsaturated carboxylic acid or by different unsaturated carboxylic
acids. In the partially esterified product, the free hydroxyl group
can be modified. For example, the free hydroxyl group can be
etherified or esterified by other carboxylic acid.
[0231] Examples of the ester include the following compounds. That
is, trimethylolpropane triacrylate, trimethylolethane triacrylate,
trimethylolpropane trimethacrylate, trimethylolethane
trimethacrylate, tetramethylene glycol dimethacrylate, triethylene
glycol dimethacrylate, tetraethylene glycol diacrylate,
pentaerythritol diacrylate, pentaerythritol triacrylate,
pentaerythritol tetraacrylate, dipentaerythritol diacrylate,
dipentaerythritol triacrylate, dipentaerythritol tetraacrylate,
dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,
tripentaerythritol octaacrylate, pentaerythritol dimethacrylate,
pentaerythritol trimethacrylate, dipentaerythritol dimethacrylate,
dipentaerythritol tetramethacrylate, tripentaerythritol
octamethacrylate, pentaerythritol diitaconate, dipentaerythritol
trisitaconate, dipentaerythritol pentaitaconate, dipentaerythritol
hexaitaconate, ethylene glycol diacrylate, 1,3-butanediol
diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol
diitaconate, sorbitol triacrylate, sorbitol tetraacrylate,
pentaerythritol-modified triacrylate, sorbitol tetramethacrylate,
sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylate
and methacrylate, glycerol diacrylate and triacrylate,
1,4-cyclohexane diacrylate, bisacrylate and bismethacrylate of
polyethylene glycol having a molecular weight of 200 to 1500, and
mixtures of the foregoing compounds.
[0232] In addition, suitable as the polymerizable compound are
amides made up of the same or different unsaturated carboxylic
acids and aromatic, alicyclic, or aliphatic polyamines having
preferably 2 to 6, particularly preferably 2 to 4, amino groups.
Examples of such polyamines are ethylenediamine, 1,2- or
1,3-propylenediamine, 1,2-1,3-, or 1,4-butylenediamine,
1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine,
dodecylenediamine, 1,4-diaminocyclohexane, isophoronediamine,
phenylenediamine, bisphenylenediamine, di-.beta.-aminoethyl ether,
diethylene triamine, triethylene tetramine, and di(-aminoethoxy)-
or di(.beta.-aminopropoxy)ethane. Other suitable polyamines are
polymers and copolymers having an additional amino group preferably
in the side chain and oligo-amides having terminal amino groups.
Examples of such unsaturated amides are methylenebisacrylamide,
1,6-hexamethylenebisacrylamide,
diethylenetriaminetrismethacrylamide,
bis(methacrylamidepropoxy)ethane, .beta.-methacrylamideethyl
methacrylate, N-[(.beta.-hydroxyethoxy) ethyl]acrylamide, and so
on.
[0233] Suitable unsaturated polyesters and polyamides can be
derived, for example, from maleic acid and from diols or diamines.
Part of the maleic acid can be replaced by other dicarboxylic acid.
These can be used together with an ethylenically unsaturated
comonomer, for example, styrene. The polyesters and polyamides can
also be derived from dicarboxylic acid and ethylenically
unsaturated diols or diamines, particularly from those having a
relatively long chain, for example, of 6 to 20 carbon atoms. An
example of the polyurethane is one made up of a saturated or
unsaturated ill diisocyanate and a saturated or unsaturated
diol.
[0234] Polybutadiene and polyisoprene as well as copolymers thereof
are conventionally known. Examples of suitable comonomers are
olefins, such as ethylene, propene, butene, and hexene,
(meth)acrylate, acrylonitrile, styrene, and vinyl chloride.
Similarly, polymers having in the side chain thereof a
(meth)acrylate group are also known. For example, these polymers
can be obtained as a reaction product from a novolak-based epoxy
resin and (meth)acrylic acid. Alternatively, these polymers may be
a homopolymer or a copolymer of a hydroxyalkyl derivative produced
by esterification with vinyl alcohol or (meth) acrylic acid; or a
homopolymer or a copolymer of a (meth) acrylate produced by
esterification with a hydroxyalkyl (meth)acrylate.
[0235] A polymeric compound having a vinyl or vinylidene group,
which is, for example, a condensation product from a polymeric
compound having in the side chain thereof a hydroxyl group, an
amino group, an epoxy group, a halogen atom, or a sulfonyloxy group
and acrylic acid, methacrylic acid, or a polymer thereof, can also
be used in the present invention.
[0236] In addition, a color-image forming material, which is, for
example, a compound having a vinyl group in the molecule of the dye
precursor, can also be used as a polymerizable compound.
[0237] In the image-forming material of the present invention, as
stated previously, the deblocking agent may have a polymerizable
group and function as a polymerizable compound, that is, the
deblocking agent may be a polymerizable compound simultaneously.
When the image-forming material of this aspect is irradiated with
light image-wise, the radical generator in the irradiated portions
undergoes a photolysis and generates a radical. The radical causes
the deblocking agent, which is a polymerizable compound, to undergo
a polymerization reaction and to harden. As a result, even if heat
and/or pressure is applied to the image-forming material after the
irradiation with light, the radical generator (including the base
to be generated from a base precursor) in the irradiated portions
does not contact or react with the dye precursor and therefore the
dye precursor does not develop a color. On the other hand, the
deblocking agent in the non- irradiated portions is diffused by the
application of heat and/or pressure and is caused to contact or
react with the dye precursor to thereby cause the dye precursor to
develop a color. Accordingly, the non-irradiated portions develop a
color, while the irradiated portions retain a white color.
[0238] The deblocking agent having a polymerizable group is
preferably a deblocking agent having in the molecule thereof a
polymerizable group such as an ethenyl group. Specific examples
thereof include the above-illustrated deblocking agents having
linked thereto directly or via a linking group such substituents as
a polymerizable ethenyl group, a (meth)acryl group, and a
(meth)acrylamido group.
[0239] More specifically, some suitable deblocking agents having a
polymerizable group are shown below. However, it should be noted
that the present invention in not limited to these blocking agents.
34
[0240] It is possible to accelerate the hardening by adding another
polymerizable compound in addition to the deblocking agent having a
polymerizable group. Examples of the other polymerizable compound
include the compounds previously listed as polymerizable
compounds.
[0241] (Other constituent components)
[0242] In the image-forming material of the present invention, in
order to accelerate the coloration reaction, it is possible to add
a color-developing aid in addition to the oxidizing agent that can
be present together with the dye precursor described above.
[0243] The color-developing aid includes a substance that enhances
the density of the color to be developed at the time of recording
by heat or pressure and a substance that reduces the lowest
coloration temperature. More specifically, the color-developing aid
is used in order to create a condition that facilitates the
reaction between the azomethine dye precursor and the deblocking
aid by lowering the melting point of the dye precursor or the
deblocking agent, by stabilizing an emulsion, or by lowering the
softening point of the wall of microcapsules.
[0244] A color-developing aid usable in the present invention is,
for example, a compound that enables low-energy printing in the
image-forming layer. Examples thereof include a phenol derivative,
a naphthol derivative, an alkoxy-substituted benzene, an
alkoxy-substituted naphthalene, an aromatic ether, a thioether, an
ester, an amide, a ureido, an urethane, a sulfonamide, a carboxyl-
or hydroxyl-containing compound, and so on.
[0245] Further, in order to accelerate the polymerization reaction,
the photopolymerizable composition of the image-forming material of
the present invention may be incorporated with an additional aid
such compound as an oxygen scavenger, a reducing agent, e.g., a
chain-transfer agent as an active hydrogen donor, or a
polymerization promoter acting in a chain-transferring manner.
[0246] Examples of the oxygen scavenger include phosphine,
phosphonate, phosphite, and other compound that can be easily
oxidized by oxygen.
[0247] Specific examples of the oxygen scavenger include
N-phenylglycine, trimethylbarbituric acid,
N,N-dimethyl-2,6-diisopropylaniline, and
N,N,N,-2,4,6-pentamethylanilinic acid. In addition, a thiol, a
thioketone, a trihalomethyl compound, a lophine dimer compound, an
iodonium salt, a sulfonium salt, an azinium salt, an organic
peroxide, a diazonium salt, a quinone diazide, and the like are
also useful as the polymerization accelerator.
[0248] (Microcapsules)
[0249] It is preferable that any one of the azomethine precursor,
capable of developing color when brought into contact with the
deblocking agent, and the deblocking agent is encapsulated in
microcapsules. For the encapsulation, a conventionally known method
can be employed. Examples of the method include a method utilizing
coacervation of a hydrophilic wall-forming material described in
U.S. Pat. Nos. 2,800,457 and 2,800,458; an interfacial
polymerization method described in U.S. Pat. No. 3,287,154, U.K.
Patent No. 990,443, and JP-B Nos. 38-19574, 42-446, and 42-771; a
method utilizing polymer deposition described in U.S. Pat. Nos.
3,418,250 and 3,660,304; a method utilizing an isocyanate-polyol
wall-forming material described in U.S. Pat. No. 3,796,669; a
method utilizing an isocyanate wall-forming material described in
U.S. Pat. No. 3,914,511; a method utilizing urea-formaldehyde and
urea-formaldehyde-resorcinol wall-forming materials described in
U.S. Pat. Nos. 4,001,140, 4,087,376, and 4,089,802; a method
utilizing wall-forming materials such as a melamine-formaldehyde
resin and hydroxypropylcellulose described in U.S. Pat. No.
4,025,455; an in-situ method utilizing a polymerization of monomers
described in JP-B No. 36-9168 and JP-A No. 51-9079; a method
utilizing electrolytic dispersion cooling described in U.K. Patent
Nos. 952,807 and 965,074; a spray-drying method described in U.S.
Pat. No. 3,111,407 and U.K. Patent No. 930,442; and methods
described in JP-B No. 7-736, JP-A No. 4-101885 and JP-A No.
9-263057.
[0250] The encapsulating method is not limited to the methods
listed above. However, it is preferable to employ an interfacial
polymerization method comprising the steps of mixing an oil phase,
prepared by dissolving or dispersing the azomethine dye precursor
in a hydrophobic organic solvent that becomes the core of the
capsules, and an aqueous phase having a water-soluble polymer
dissolved therein, emulsifying the mixture by means of a
homogenizer or the like, heating the emulsion so as to cause a
polymer-forming reaction at the intersurface of droplets so that
polymeric microcapsule walls are formed. This method makes it
possible to form capsules having uniform particle diameters in a
short period of time and to obtain a recording material excellent
in storability as a raw recording material.
[0251] The reactants that form the polymer are added to the inside
of the droplets and/or the outside of the droplets. Examples of the
polymeric substance include polyurethane, polyurea, polyamide,
polyester, polycarbonate, urea/formaldehyde resins, melamine
resins, polystyrene, styrene/methacrylate copolymers,
styrene/acrylate copolymers, and soon. Among these substances,
polyurethane, polyurea, polyamide, polyester, and polycarbonate are
preferable, and polyurethane and polyurea are particularly
preferable. The above-listed polymeric substances may be used in
combinations of two or more kinds.
[0252] Examples of the water-soluble polymers include gelatin,
polyvinyl pyrrolidone, polyvinyl alcohol, and so on. For example,
when polyurethane is used as capsule wall material, the
microcapsule wall can be formed by mixing a polyvalent isocyanate
and a second substance (e.g., polyol or polyamine) that reacts
therewith to form the capsule wall in a water-soluble polymer
solution (i.e., aqueous phase) or in an oily medium (oil phase) to
be encapsulated, emulsifying the mixture, and heating the resulting
emulsion so as to cause a polymer-forming reaction at the
intersurface of droplets.
[0253] As the polyvalent isocyanate and the polyol or polyamine,
with which the polyvalent isocyanate reacts, those which are
described in U.S. Pat. Nos. 3,281,383, 3,773,695, and 3,793,268,
JP-B Nos. 48-40347 and 49-24159, JP-A Nos. 48-80191 and 48-84086,
and K., Iwata, "Polyurethane Handbook", Nikkan Kogyo Shinbun Ltd.,
1987, can be used.
[0254] When microcapsules containing the azomethine dye precursor
are prepared, the azomethine dye precursor to be enclosed in the
microcapsules may be present in solution form or may be present in
solid form inside the microcapsules. Generally, the solvent (oily
medium) can be selected from high-boiling oils. Examples of the
solvent that can be used include a phosphate, a phthalate, an
acrylate, a methacrylate, other carboxylates, a fatty acid amide,
an alkylated biphenol, an alkylated terphenol, a chlorinated
paraffin, an alkylated naphthalene, diallylethane, a compound that
is a solid at room temperature, an oligomer oil, a polymer oil, and
so on. Specific examples of the solvent include the solvents
described in JP-A Nos. 60-242094 and Japanese Patent Application
No. 62-75409. These solvents may not be used at the time of
encapsulation.
[0255] When enclosing the azomethine dye precursor in solution form
inside the microcapsules, the azomethine dye precursor, which is
dissolved in a solvent, may be encapsulated. In this case, the
amount of the solvent to be used is preferably 1 to 500 parts by
weight per 100 parts by weight of the azomethine dye precursor.
When the azomethine dye precursor to be encapsulated has a poor
solubility in the solvent or when the solvent described above is
not used, a low-boiling solvent having a high solvency may be used
as an auxiliary solvent. Examples of the low-boiling solvent
include ethyl acetate, propyl acetate, isopropyl acetate, butyl
acetate, methylene chloride, and so on.
[0256] An aqueous solution having a water-soluble polymer dissolved
therein is used as the aqueous phase. The oil phase described above
is added to the aqueous phase and thereafter the mixture is
emulsified by means of a homogenizer or the like. The water-soluble
polymer acts as a dispersing medium which enables uniform and easy
dispersion and stabilizes the aqueous dispersion thus obtained. In
this case, in order to obtain a further uniform and stable
dispersion, a surfactant may be added to at least one of the oil
phase and the aqueous phase. As the surfactant, a conventionally
known surfactant for emulsification may be used.
[0257] An example, in which the azomethine dye precursor is
enclosed in microcapsules, is explained above. In the image-forming
material, however, as stated previously, the deblocking agent may
be enclosed in microcapsules. The aspect, in which the deblocking
agent is enclosed in microcapsules, is similar to the example in
which the azomethine dye precursor is enclosed in
microcapsules.
[0258] When any one of the azomethine dye precursor and the
deblocking agent is encapsulated, the average particle diameter of
the microcapsules is preferably 20 .mu.m or less, and more
preferably 7 .mu.m or less, from the standpoint of obtaining high
resolution. If the microcapsules formed are too small, a larger
amount of capsule wall-forming agents is required because the
surface area per unit amount of the solid components becomes
larger. Therefore, the average particle diameter of the
microcapsules is preferably 0.1 .mu.m or greater.
[0259] Among the image-forming materials of the present invention
which use microcapsules, in those which are heat-sensitive,
substances pass through the microcapsule wall when the
image-forming material is heated. Since the microcapsules are not
broken when the substances pass through the microcapsule wall,
color is developed inside the microcapsules or in the area very
close to the periphery of the microcapsules. As a result, the image
granularity is excellent.
[0260] Among the image-forming materials of the present invention
which use microcapsules, in those which are pressure-sensitive, the
enclosed substances can be diffused to the outside by the
microcapsule being broken. Therefore, in comparison with the
heat-sensitive image-forming material using microcapsules, the
pressure-sensitive image-forming material using microcapsules tends
to be more blurred. Accordingly, the (photo-sensitive)
heat-sensitive image-forming material using microcapsules is
preferable to the (photo-sensitive) pressure-sensitive
image-forming material using microcapsules with respect to
sharpness and blurriness of images.
[0261] (Specific construction of the image-forming layer)
[0262] According to the image-forming material of the present
invention, the image-forming layer contains at least one azomethine
dye precursor of the present invention and at least one deblocking
agent. From the standpoint of photosensitivity, processing speed,
and image durability, it is preferable that the image-forming layer
further contains at least one photopolymerization initiator and at
least one polymerizable compound. If necessary, these components
are enclosed in microcapsules and used in the preparation of a
coating liquid by being dissolved, emulsified, or dispersed in a
suitable solvent together with other additives which are used when
necessary. The image-forming layer is formed by applying the
coating liquid thus obtained onto a support by a conventionally
known method and drying the coating layer.
[0263] When the image-forming material of the present invention is
used as a multicolor material, generally the image-forming layer is
formed by laminating a plurality of image-forming layers developing
different hues onto a support such that each image-forming layer
contains microcapsules containing an azomethine dye precursor
developing different hues, a photopolymerization initiator, and
other component. The two or more types of microcapsules which each
contain at least one azomethine dye precursor which develops a
different hue, at least one photopolymerization initiator, and
other components may all be contained in one layer (needless to
say, the component to be enclosed in the microcapsules may be the
deblocking agent). When the image-forming material is irradiated
with light, the image-forming material is sensitized by the
different wavelengths of the light source and multicolor images are
formed.
[0264] In addition, when image-forming layers developing different
hues are laminated, an interlayer, which may contain a filter dye,
may be provided between single-color, image-forming layers
constituting the image-forming layer.
[0265] The interlayer comprises a binder as a main component and
may contain additives such as a hardener, a polymer latex, mica, an
ultraviolet absorber, and the like, when necessary. When a filter
dyes is used in an interlayer, although the filter dye may be
selected from the spectral sensitizing dyes described previously,
it is preferable to use a compound having the same light absorption
wavelength as that of the spectral sensitizing compound contained
in the layer overlying the interlayer in view of the formation of
sharp images.
[0266] The dye for filter can be added to a desired layer, an
interlayer in particular, as a dispersion prepared by emulsifying
dispersion of the dye according to an oil-in-water or polymer
dispersing method.
[0267] According to the oil-in-water dispersing method, the dye for
filter is dissolved in any one or a mixture of a high-boiling
organic solvent having a boiling point of 175.degree. C. or above
and a low-boiling solvent having a boiling point of 30 to
160.degree. C., and the resulting solution is finely dispersed in
an aqueous medium, such as water, an aqueous solution of gelatin,
or an aqueous solution of polyvinyl alcohol, in the presence of a
surfactant.
[0268] Examples of the high-boiling solvent are described in, for
example, U.S. Pat. No. 2,322,027. The same solvents as the solvents
for the formation of microcapsules described previously can be
preferably used as the high-boiling organic solvents and the
low-boiling solvents.
[0269] The dispersing may be followed by a phase inversion.
Further, if necessary, the low-boiling solvent may be removed or
lessened by distillation, noodle-water washing, ultrafiltration, or
the like, and thereafter the dispersion may be used for
coating.
[0270] The details of the polymer dispersion process and hardening
as well as specific examples of the latex are described in, for
example, U.S. Pat. Nos. 4,199,383, German Patent Application (OLS)
Nos. 2,541,274 and 2-541,230, JP-A Nos. 49-74538, 51-59943, and
54-32552, and Research Disclosure, Vol. 148 (1976), August, Item
14850.
[0271] Preferable examples of the latex described above are latices
produced by copolymerization between acrylates or methacrylates
(e.g., ethyl acrylate, n-butyl acrylate, n-butyl methacrylate, and
2-acetoacetoxyethyl methacrylate) and acid monomers (e.g., acrylic
acid and 2-acrylamide-2-methylpropanesulfonic acid).
[0272] It is also possible to provide a layer containing a polymer,
which reduces oxygen transmissivity, such as gelatin, PVA, or the
like, between the support and the photosensitive layer
(image-forming layer). The formation of such layer makes it
possible to prevent the images from fading due to
photooxidation.
[0273] In addition, a so-called antihalation layer can be provided
between the support and the photosensitive layer or on the side
opposite to the photosensitive layer in the case where the support
is transparent. Where an antihalation layer is formed, from the
standpoint of enhancement of the whiteness of the background, it is
preferable that the antihalation layer can be bleached with light
or heat. In the case where the antihalation layer is bleached with
light, for example, a combination of a dye and a boron compound can
be utilized. In the case where the antihalation layer is bleached
with heat, for example, a process, in which the dye in color
developed by a deblocking agent or a nucleophilic agent is
bleached, can be utilized.
[0274] In order to raise the durability of images to light and heat
or in order to reduce the yellowing due to light after the fixing
of images, it is preferable to use the following conventionally
known antioxidants or the like in the image-forming layer of the
image-forming material of the present invention.
[0275] The above-mentioned antioxidants are described in, for
example, European Patent Application Laid-Open Nos. 223739, 309401,
309402, 310551, 310552, and 459416, German Patent -Application
Laid-Open No. 3435443, JP-A Nos. 54-48535, 62-262047, 63-113536,
63-163351,2-262654, 2-71262,3-121449, -5-61166, and 5-119449, and
U.S. Pat. Nos. 4814262, and 4980275.
[0276] It is also effective to use additives, conventionally known
in heat-sensitive recording materials and pressure-sensitive
recording materials, in the image-forming layer in the
image-forming material of the present invention. Specific examples
of these additives include the compounds described in JP-A Nos.
60-107384, 60-107383, 60-125470, 60-125471, 60-125472, 60-287485,
60-287486, 60-287487, 60-287488, 61-160287, 61-185483, 61-211079,
62-146678, 62-146680, 62-146679, 63-051174, 63-203372, 63-224989,
63-251282, 63-267594, and JP-B Nos. 48-043294 and 48-033212.
[0277] Conventionally known water-soluble polymeric compounds and
latices can be used as binders for use in the image-forming layer
of the image-forming material of the present invention. Examples of
the water-soluble polymeric compounds include methyl cellulose,
carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl
cellulose, starch derivatives, casein, gum arabic, gelatin,
ethylene/maleic anhydride copolymers, styrene/maleic anhydride
copolymers, polyvinyl alcohol, epichlorohydrin-modified polyamide,
isobutylene/maleic anhydride/salicylic acid copolymers, polyacrylic
acid, polyacrylic acid amide, and modified products thereof.
Examples of the latex include styrene/butadiene rubber latices,
methyl acrylate/butadiene rubber latices, vinyl acetate emulsions,
and so on.
[0278] The pigments that can be used in the image-forming material
of the present invention may be any conventionally known organic or
inorganic pigments. Examples of the pigments include kaolin,
calcined kaolin, talc, pagodite, diatomaceous earth, calcium
carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide,
lithopone, amorphous silica, colloidal silica, calcined gypsum,
silica, magnesium carbonate, titanium oxide, alumina, barium
carbonate, barium sulfate, mica, microballoon, urea/formalin
filler, polyester particles, cellulose filler, and so on.
[0279] When necessary, conventionally known additives, such as
waxes, antistatic agents, defoaming agents, electroconducting
agents, fluorescent dyes, surfactants, ultraviolet absorbers, and
precursors thereof, can be used in the image-forming layer of the
image-forming material of the present invention.
[0280] C: Protective Layer
[0281] When necessary, a protective layer may be provided on the
image-forming layer of the image-forming material of the present
invention. If necessary, two or more protective layers may be
laminated. Examples of the material for use in the protective layer
include water-soluble polymeric compounds such as polyvinyl
alcohol, carboxy-modified polyvinyl alcohol, vinyl
acetate/acrylamide copolymers, silicon-modified polyvinyl alcohol,
starch, modified starch, methyl cellulose, carboxymethyl cellulose,
hydroxymethyl cellulose, gelatins, gum arabic, casein, hydrolysates
of styrene/maleic acid copolymers, hydrolysates of half esters of
styrene/maleic acid copolymers, hydrolysates of isobutylene/maleic
acid copolymers, polyacrylamide derivatives, polyvinyl pyrrolidone,
polystyrenesulfonic acid sodium salts, and sodium alginate; and
latices such as styrene/butadiene rubber latices,
acrylonitrile/butadiene rubber latices, methyl acrylate/butadiene
rubber latices, and vinyl acetate emulsions. The water-soluble
polymeric compounds in the protective layer may be crosslinked so
that the storability is further enhanced. The crosslinking agent
may be a conventionally known one. Specific examples of the
crosslinking agent include water-soluble, initial-stage
condensation products such as N-methylol urea, N-methylol melamine,
and urea/formalin; dialdehyde compounds such as glyoxal, and
glutaraldehyde; inorganic crosslinking agents such as boric acid
and borax; and polyamideepichlorohydrin. The protective layer may
be hardened by electron beams. Conventionally known additives, such
as pigments, metal soaps, waxes, surfactants, fluorescent
brighteners, and ultraviolet -, -absorbers, can be used in the
protective layer. The coating weight of the protective layer is
preferably 0.2 to 5 g/m.sup.2 and more preferably 0.5 to 2
g/m.sup.2. The thickness is preferably 0.2 to 5 .mu.m and more
preferably 0.5 to 2 .mu.m.
[0282] [3. Image-forming Method]
[0283] Next, the image-forming method of the present invention is
explained. The image-forming method of the present invention is a
method using the image-forming material of the present invention.
According to the image-forming method of the present invention,
high-quality and highly durable images can be formed rapidly and
with high sensitivity.
[0284] (The 1st image-forming method)
[0285] Where microcapsules are used in the image-forming layer in
the image-forming material of the present invention, images can be
formed by applying heat and/or pressure image-wise onto the
image-forming layer. On the other hand, where microcapsules are not
used in the image-forming layer and the azomethine dye precursor
does not develop color by the action of the deblocking agent alone
at room temperature, images can be formed by applying heat
image-wise onto the image-forming layer. This is because the
contact of the azomethine dye precursor with the deblocking agent
or the contact while being heated enables the deblocking agent to
cause the azomethine dye precursor to develop a color so that
images are formed. Unlike the image-forming material which develops
color by heat alone, the image-forming material based on the
color-developing mechanism described above is less liable to
produce fogging in non-image portions and the images obtained can
become highly durable by carrying out the same fixing as in the
fixing step in the 2nd image-forming method described later.
[0286] (The 2nd image-forming method)
[0287] Where a polymerizable compound and a polymerization
initiator are present in the image-forming layer in the
image-forming material of the present invention, images can be
formed by a latent-image forming step and a step in which the image
is made visible, wherein in the latent-image forming step the
image-forming layer is irradiated image-wise with light capable of
being absorbed by the polymerization initiator so that
polymerization initiator develops a polymerization-starting species
which causes the polymerizable compound to undergo a polymerization
to thereby form a latent image in the irradiated portions, and
wherein heat and/or pressure is applied to the entire surface of
the image-forming layer in the step in which the image is made
visible and the heat and/or pressure causes the contact of the
azomethine dye precursor with the deblocking agent in accordance
with the latent image so that colored images are formed.
[0288] Since the intensity of the light for irradiation in the
latent-image forming step is not more than the intensity required
for the photopolymerization initiator to develop the polymerization
species so that the polymerizable compound undergoes a
polymerization, a high sensitivity is obtained and the processing
speed is high. In addition, since the photopolymerization initiator
can be selected from a variety of photopolymerization initiators
responsive to wavelengths ranging from ultraviolet to near
infrared, that is, since the light source can be selected from a
variety of light sources having a wide range of coloration
wavelengths, the occurrence of color mixing is less likely and an
inexpensive light source can be adopted, thereby making it possible
for a low-cost image-forming method to be provided.
[0289] A laser, an LED, xenon light, a fluorescent lamp, a mercury
lamp, a tungsten lamp, a metal halide lamp, and the like can be
used as the light source. It is also possible to use light sources
having two or more wavelengths to match the organic dyes to be
used.
[0290] Although the irradiation with light is normally carried out
from the image-forming layer side of the image-forming material,
the irradiation with light can also be carried out from the support
side when the support for the image-forming material is
transparent.
[0291] The upper limit of the temperature for heating the entire
surface in the step in which the image is made visible is a
temperature not exceeding the temperature that does not allow the
azomethine dye precursor to develop a color on its own unless the
deblocking agent is present. If the heating temperature is
controlled within this range, the fogging in white portions
(non-image portions) does not occur.
[0292] Where the image-forming material is prepared by using
microcapsules, the heat and/or pressure to be applied onto the
entire surface of the image-forming layer may be the heat and/or
pressure sufficient to break the microcapsules (the term "break" in
this case includes the state in which the substance outside the
microcapsules penetrates into the microcapsules).
[0293] Although the conditions, such as the heat and/or pressure to
be applied onto the entire surface of the image-forming layer and
the time period, may be appropriately set by taking into account
such factors as kinds and concentrations of the azomethine dye
precursor and the deblocking agent and the capsule wall material
when the microcapsules are used, the heating temperature is
preferably 50 to 180.degree. C. and more preferably 70 to
130.degree. C. Where heat and/or pressure is applied onto the
entire surface of the image-forming layer, examples of the heat
source usable for the heating include a heat roller, a heat head, a
heat stamp, near infrared (laser), infrared (laser), and so on.
[0294] After the step in which the image is made visible, if the
obtained image is directly subjected to image processing or the
like, a fixing step is not required. However, in order to obtain
highly durable images, it is preferable to provide, after the step
in which the image is made visible, a fixing step in which the
image is fixed by irradiating the entire surface of the
image-forming layer with light.
[0295] The fixing step enables the entire image, including image
portions and non-image portions, to undergo a polymerization and to
obtain highly durable, superior, fixed images simply. Where a dye
is incorporated as a component of the photopolymerization
initiator, since the dye is bleached in the fixing step described
above, images having a higher level of whiteness and free from
background fogging in the non-image portions can be obtained.
[0296] Since the light source for use in the fixing step is not for
image-wise writing but for irradiating the whole image-forming
layer of the image-forming material, the light source is not
expensive even if it is a high-power light source. Therefore, the
use of the light source presents no impediment to cost reduction
and to the speed of the processing.
EXAMPLES
[0297] The examples of the present invention will now be explained
below. However, it should be noted that the present invention is
not limited to these examples. In the following examples, "%" means
"weight %" unless otherwise specified.
[0298] 1. Preparation of a Dye Precursor-enclosing Microcapsule
Liquid
[0299] 1-a Preparation of a Microcapsule Dispersion Liquid (1)
[0300] 4.16 g of the azomethine dye precursor compound (33) of the
present invention was dissolved in 18.4 g of ethyl acetate. To the
solution were added 14 g of "TAKENATE D-110N" (manufactured by
Takeda Chemical Industries, Ltd.). The resulting solution was added
to a mixture of 70 g of a 6% solution of phthalated gelatin and
0.34 g of a 10% solution of sodium dodecylbenzenesulfonate. The
resulting mixture was emulsified by using a homogenizer
(manufactured by NIPPON SEIKI Co., Ltd.) at 10000 rpm for 10
minutes and an emulsion was obtained. To the emulsion thus obtained
were added 54 g of water and 0.62 g of tetraethylene pentamine.
After that, while being stirred, the mixture was heated to
65.degree. C. and was kept at that temperature for 3 hours. In this
way, a dye precursor-enclosing microcapsule liquid (1), enclosing
the compound (33) as the core and having an average microcapsule
diameter of 0.5 .mu.m, was prepared
[0301] 1-b. Preparation of a Microcapsule Dispersion Liquid (2)
[0302] A microcapsule dispersion liquid (2) was prepared in the
same way as in 1-a., except that the compound (18) of the present
invention was used in place of the compound (33) of the present
invention.
[0303] 1-c. Preparation of a Microcapsule Dispersion Liquid (3)
[0304] A microcapsule dispersion liquid (3) was prepared in the
same way as in 1-a., except that the compound (2 2) of the present
invention was used in place of the compound (33) of the present
invention.
[0305] 1-d. Preparation of a Microcapsule Dispersion Liquid (4)
[0306] A microcapsule dispersion liquid (4) was prepared in the
same way as in 1-a., except that the compound (31) of the present
invention was used in place of the compound (33) of the present
invention.
[0307] 1-e. Preparation of a Microcapsule Dispersion Liquid (5)
[0308] A microcapsule dispersion liquid (5) was prepared in the
same way as in 1-a., except that the compound (40) of the present
invention was used in place of the compound (33) of the present
invention.
[0309] 1-f. Preparation of a Microcapsule Dispersion Liquid (6)
[0310] A microcapsule dispersion liquid (6) was prepared in the
same way as in 1-a., except that the compound (41) of the present
invention was used in place of the compound (33) of the present
invention.
[0311] 1-g. Preparation of a Microcapsule Dispersion Liquid (7)
[0312] 4.16 g of the compound (33) of the present invention was
dissolved in 18.4 g of ethyl acetate. To the solution were added
0.05 g of a dye represented by the following structural formula (1)
and 0.4 g of an organoboron compound represented by the following
structural formula (m) as constituents of a photopolymerization
initiator, 3 g of pentaerythritol tetramethacrylate as a
polymerizable compound, 2 g of tricresyl phosphate, and 14 g of
"TAKENATE D-110N" (manufactured by Takeda Chemical Industries,
Ltd.) as an encapsulant. The resulting solution was added to a
mixture of 70 g of a 6% solution of phthalated gelatin and 0.34 g
of a 10% solution of sodium dodecylbenzenesulfonate. The resulting
mixture was emulsified by using a homogenizer (manufactured by
NIPPON SEIKI Co., Ltd.) at 10000 rpm for 10 minutes and an emulsion
was obtained. To the emulsion thus obtained were added 54 g of
water and 0.62 g of tetraethylene pentamine. After that, while
being stirred, the mixture was heated to 65.degree. C. and was kept
at that temperature for 3 hours. In this way, a microcapsule
dispersion liquid (7), enclosing the photopolymerization initiator,
polymerizable compound, and oil together with the compound (33) as
the core materials and having an average microcapsule diameter of 4
.mu.m, was prepared. 35
[0313] 1-h. Preparation of a Microcapsule Dispersion Liquid (8) For
comparison
[0314] A microcapsule dispersion liquid (8) was prepared in the
same way as in 1-a., except that a compound represented by the
following structural formula was used in place of the compound (33)
of the present invention. 36
[0315] 1-i. Preparation of a Microcapsule Dispersion Liquid (9) For
Comparison
[0316] A microcapsule dispersion liquid (9) was prepared in the
same way as in 1a., except that a compound represented by the
following structural formula was used in place of the compound (33)
of the present invention. 37
[0317] 1-j. Preparation of a Microcapsule Dispersion Liquid (10)
For Comparison
[0318] A microcapsule dispersion liquid (10) was prepared in the
same way as in 1-a., except that a compound represented by the
following structural formula was used in place of the compound (33)
of the present invention. 38
[0319] 1-k. Preparation of a Microcapsule Dispersion Liquid (11)
For Comparison
[0320] A microcapsule dispersion liquid (11) was prepared in the
same way as in 1-a., except that a compound represented by the
following structural formula was used in place of the compound (33)
of the present invention. 39
[0321] 2. Preparation of Acid Emulsions
[0322] 2-a. Preparation of an Acid Emulsion (1)
[0323] 2.4 g of mono-2-ethylhexyl phthalate, 1.2 g of a sulfonamide
compound (1) indicated below, and 1.2 g of a sulfonamide compound
(2) indicated below were dissolved in 20.1 g of isopropyl acetate.
The resulting solution was added to a mixture of 37.1 g of a 10%
aqueous solution of gelatin and 1.35 g of a 10% aqueous solution of
sodium dodecylbenzenesulfonate. The resulting mixture was
emulsified by using a homogenizer at 15000 rpm for 5 minutes and an
emulsified liquid was obtained. After that, the emulsified liquid
was stirred at 40.degree. C. for 3 hours to thereby evaporate the
isopropyl acetate. In this way, an acid emulsion (1) was prepared.
40
[0324] 2-b. Preparation of an Acid Emulsion (2)
[0325] An acid emulsion (2) was prepared in the same way as in 2-a
., except that 2-ethylhexyl 3-chloro-4-hydroxybenzoate was used in
place of mono-2-ethylhexyl phthalate.
[0326] 2-c. Preparation of an Acid Emulsion (3)
[0327] 0.4 g of IRGACURE 907, 4.2 g of a compound represented by
the following structural formula (a) as an acid also acting as a
polymerizable compound, 2 g of the amide compound (1), and 2 g of
the amide compound (2), i.e., the same compounds as those used in
2-a., were dissolved in 10.5 g of ethyl acetate. To the solution
were added 0.48 g of tricresyl phosphate as a high-boiling solvent,
0.24 g of diethyl maleate, and 1.27 g of PIONIN A41C (manufactured
by Takemoto Yushi Co. , Ltd.). After that, the mixture was heated
to thereby obtain a homogeneous liquid. The resulting liquid was
added to a mixture of 40 g of a 8% aqueous solution of gelatin (No.
750 Gelatin, manufactured by Nitta Gelatin Co., Ltd.). The
resulting mixture was emulsified by means of a homogenizer at 10000
rpm for 5 minutes and an emulsified liquid was obtained. Then, the
remaining ethyl acetate was evaporated from the emulsified liquid.
In this way, an acid emulsion (3) was prepared. 41
[0328] 2-d. Preparation of an Acid Emulsion (4)
[0329] An acid emulsion (4) was prepared in the same way as in
2-c., except that a compound having the following structural
formula (b) was used in place of the compound (a) of the acid
emulsion (3). 42
[0330] 2-e. Preparation of an Acid Emulsion (5)
[0331] An acid emulsion (5) was prepared in the same way as in
2-c., except that 0.07 g of a dye having the following structural
formula (c) and 0.5 g of an organoboron compound having the
following structural formula (d) were used in place of IRGACURE 907
of the acid emulsion (3). 43
[0332] 2-f. Preparation of an Acid Emulsion (6)
[0333] An acid emulsion (6) was prepared in the same way as in
2-d., except that a dye having the structural formula (c) described
above and an organoboron compound having the structural formula (d)
described above were used in place of IRGACURE 907 of the acid
emulsion (4).
[0334] 2-g. Preparation of an Acid Emulsion (7)
[0335] An acid emulsion (7) was prepared in the same way as in
2-f., except that a dye having the following structural formula (e)
was used in place of the dye (c) and an organoboron compound having
the following structural formula (f) was used in place of the
organoboron compound (d) of the acid emulsion (6). 44
[0336] 3. Preparation of Base Emulsions
[0337] 3-a. Preparation of a Base Emulsion (1)
[0338] A base emulsion (1) was prepared in the same way as in 2-a.,
except that N-methyloctadecylamine was used in place of the
mono-2-ethylhexyl phthalate used in the acid emulsion (.).
[0339] 3-b. Preparation of a Base Emulsion (2)
[0340] A base emulsion (2) was prepared in the same way as in 2-c.,
except that a compound having the following structural formula (g)
was used in place of the polymerizable compound (a) used in the
acid emulsion (3). 45
[0341] 3-c. Preparation of a Base Emulsion (3)
[0342] A base emulsion (3) was prepared in the same way as in 2-e.,
except that a compound having the structural formula (g) described
above was used in place of the polymerizable compound (a) used in
the acid emulsion (5).
[0343] 4. Preparation of Oxidizing Agent Emulsions
[0344] 4-a. Preparation of an Oxidizing Agent Emulsion (1)
[0345] An oxidizing agent emulsion (1) was prepared in the same way
as in 2-a., except that
4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl was used in place of
the mono-2-ethylhexyl phthalate used in the acid emulsion (1).
[0346] 4-b. Preparation of an Oxidizing Agent Emulsion (2)
[0347] An oxidizing agent emulsion (2) was prepared in the same way
as in 2-c., except that trimethylolpropane trimethacrylate and
4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl were used in place
of the polymerizable compound (a) used in the acid emulsion
(3).
[0348] 4-c. Preparation of an Oxidizing Agent Emulsion (3)
[0349] An oxidizing agent emulsion (3) was prepared in the same way
as in 2-e., except that trimethylolpropane trimethacrylate and
4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl were used in place
of the polymerizable compound (a) used in the acid emulsion
(5).
[0350] 5. Preparation of Alkylating Agent Emulsions
[0351] 5-a. Preparation of an Alkylating Agent Emulsion (1)
[0352] An alkylating agent emulsion (1) was prepared in the same
way as in 2-a., except that 2-(2,5-di-t-amylphenyloxy)ethyl
5-bromo-valerate was used in place of the mono-2-ethylhexyl
phthalate used in the acid emulsion (1).
[0353] 5-b. Preparation of an Alkylating Agent Emulsion (2)
[0354] An alkylating agent emulsion (2) was prepared in the same
way as in 2-c., except that a compound having the following
structural formula (h) was used in place of the polymerizable
compound (a) used in the acid emulsion (3). 46
[0355] 5-c. Preparation of an Alkylating Agent Emulsion (3)
[0356] An alkylating agent emulsion (3) was prepared in the same
way as in 2-e., except that a compound having the structural
formula (h) described above was used in place of the polymerizable
compound (a) used in the acid emulsion (5).
[0357] 6. Preparation of a Metal Salt Emulsion
[0358] A metal salt emulsion was prepared in the same way as in
2-a., except that zinc 3,5-di(a-methylbenzyl)salicylate was used in
place of the mono-2-ethylhexyl phthalate used in the acid emulsion
(1).
[0359] 7. Preparation of a Liquid For Coating a Protective
Layer
[0360] A liquid for coating a protective layer was prepared by
blending 2.6 g of the following surfactant (1) and 7.7 g of the
following surfactant (2) into 113.5 g of a 9% gelatin aqueous
solution. 47
[0361] 8. Support
[0362] A 100 .mu.m-thick, white polyester base (E68L, manufactured
by Toray Industries, Inc.) was used.
Example 1
[0363] A liquid for coating an image-forming layer was prepared by
blending the microcapsule dispersion liquid (1) and the acid
emulsion (1) so that the concentration of the azomethine dye
precursor (i.e., the compound (33) of the present invention) was
0.75.times.10.sup.-3 mol/m.sup.2 and the concentration of
mono-2-ethylhexyl phthalate was 1.5.times.10.sup.-3 mol/m.sup.2.
The liquid was applied onto the support by using a coating bar and
the coating layer was dried at 30.degree. C. for 10 minutes. In
this way, an image-forming layer was formed. Next, the liquid for
coating a protective layer was applied onto the image-forming layer
by using a coating bar so that the dry weight of the protective
layer was 2.0 g/m.sup.2. After that, the coating layer was dried at
30.degree. C. for 10 minutes. In this way, an image-forming
material of Example 1 was obtained.
Example 2
[0364] The image-forming material of Example 2 was obtained in the
same way as in Example 1, except that the acid emulsion (2) was
used in place of the acid emulsion (1) used in Example 1.
Example 3
[0365] The image-forming material of Example 3 was obtained in the
same way as in Example 2, except that the microcapsule dispersion
liquid (2) was used in place of the microcapsule dispersion liquid
(1) used in Example 2.
Example 4
[0366] The image-forming material of Example 4 was obtained in the
same way as in Example 2, except that the microcapsule dispersion
liquid (3) was used in place of the microcapsule dispersion liquid
(1) used in Example 2.
Example 5
[0367] The image-forming material of Example 5 was obtained in the
same way as in Example 2, except that the microcapsule dispersion
liquid (4) was used in place of the microcapsule dispersion liquid
(1) used in Example 2.
Example 6
[0368] The image-forming material of Example 6 was obtained in the
same way as in Example 2, except that the microcapsule dispersion
liquid (5) was used in place of the microcapsule dispersion liquid
(1) used in Example 2.
Example 7
[0369] The image-forming material of Example 7 was obtained in the
same way as in Example 2, except that the microcapsule dispersion
liquid (6) was used in place of the microcapsule dispersion liquid
(1) used in Example 2.
Example 8
[0370] The image-forming material of Example 8 was obtained in the
same way as in Example 1, except that the base emulsion (1) was
used in place of the acid emulsion (1) used in Example 1.
Example 9
[0371] The image-forming material of Example 9 was obtained in the
same way as in Example 1, except that the oxidizing agent emulsion
(1) was used in place of the acid emulsion (1) used in Example
1.
Example 10
[0372] The image-forming material of Example 10 was obtained in the
same way as in Example 1, except that the alkylating agent emulsion
(1) was used in place of the acid emulsion (1) used in Example
1.
Example 11
[0373] The image-forming material of Example 11 was obtained in the
same way as in Example 1, except that the metal salt emulsion was
used in place of the acid emulsion (1) used in Example 1.
[0374] (Image formation using the image-forming materials of
Examples 1 to 11 and assessment thereof)
[0375] When the image-forming materials of Examples 1 to 11 were
each heated image-wise for 15 seconds at 120.degree. C. by means of
a hot plate, the image-forming materials of Examples 6 and 7
developed a cyan color and the other image-forming materials
developed a magenta color. The density of the developed color in
image portions and the background fogging of the non-image portions
were measured using a Macbeth reflection densitometer (RD918),
wherein a cyan filter was used for the image-forming materials of
Examples 6 and 7 while a magenta filter was used for the other
image-forming materials.
[0376] Further, after the image-forming materials were left in an
environment of 40.degree. C./90% RH for one day, the background
fogging was measured in the same way. The results are shown in
Table 1.
1 TABLE 1 Immediately after coating After being left at 40.degree.
C./ Density of the 90% RH for one day developed color Fogging
Fogging Example 1 2.3 0.04 0.05 Example 2 2.2 0.04 0.05 Example 3
2.3 0.05 0.05 Example 4 2.4 0.05 0.06 Example 5 2.4 0.06 0.07
Example 6 2.4 0.05 0.05 Example 7 2.3 0.04 0.05 Example 8 2.4 0.05
0.06 Example 9 2.5 0.06 0.06 Example 10 2.3 0.05 0.05 Example 11
2.3 0.05 0.05
[0377] Based on the results shown in Table 1, it is found that the
image-forming materials of the present invention exhibit excellent
density of developed color, less background fogging, and excellent
storability.
Comparative Examples 1 to 11
[0378] The image-forming materials of Comparative Examples 1 to 11
were obtained in the same way as in Examples 1 to 11, except that
the respective deblocking agent emulsions were not incorporated
into the liquids for coating image-forming layers in Examples 1 to
11.
[0379] (Image formability test by using the image-forming materials
of Comparative Examples 1 to 11)
[0380] When the image-forming materials of Comparative Examples 1
to 11 were each heated for 15 seconds at 120.degree. C. by means of
a hot plate, the image-forming materials did not develop a color.
Even when the image-forming materials were each heated for further
15 seconds at 120.degree. C., the image-forming materials did not
develop a color. The color densities of the image-forming materials
of Comparative Examples 1 to 11 before and after the treatments
described above were measured using a Macbeth reflection
densitometer (RD918). The results are shown in Table 2.
2 TABLE 2 Fresh 120.degree. C., 15 sec. 150.degree. C., 15 sec.
Comparative Example 1 0.05 0.05 0.05 Comparative Example 2 0.04
0.04 0.04 Comparative Example 3 0.06 0.06 0.06 Comparative Example
4 0.05 0.05 0.05 Comparative Example 5 0.05 0.05 0.05 Comparative
Example 6 0.05 0.05 0.05 Comparative Example 7 0.06 0.06 0.06
Comparative Example 8 0.04 0.04 0.04 Comparative Example 9 0.04
0.04 0.04 Comparative Example 10 0.05 0.05 0.05 Comparative Example
11 0.05 0.05 0.05
[0381] Based on the results shown in Table 2, it is found that the
microcapsules, which enclose the azomethine dye precursor, do not
develop a color by themselves even if heated to a predetermined
temperature.
Example 12
[0382] The image-forming material of Example 12 was obtained in the
same way as in Example 1, except that the acid emulsion (1) in
Example 1 was replaced by the acid emulsion (3) (the concentration
was adjusted based on the acid also acting as a polymerizable
compound).
Example 13
[0383] The image-forming material of Example 13 was obtained in the
same way as in Example 1, except that the acid emulsion (1) in
Example 1 was replaced by the acid emulsion (4) (the concentration
was adjusted based on the acid also acting as a polymerizable
compound).
Example 14
[0384] The image-forming material of Example 14 was obtained in the
same way as in Example 6, except that the acid emulsion (2) in
Example 6 was replaced by the base emulsion (2) (the concentration
was adjusted based on the base).
Example 15
[0385] The image-forming material of Example 15 was obtained in the
same way as in Example 4, except that the acid emulsion (2) in
Example 4 was replaced by the oxidizing agent emulsion (2) (the
concentration was adjusted based on the oxidizing agent).
Example 16
[0386] The image-forming material of Example 16 was obtained in the
same way as in Example 3, except that the acid emulsion (2) in
Example 3 was replaced by the alkylating agent emulsion (2) (the
concentration was adjusted based on the alkylating agent).
[0387] (Image formation using the image-forming materials of
Examples 12 to 16 and assessment thereof)
[0388] The image-forming materials of Examples 12 to 16 obtained
above were each exposed to light by using a vacuum printing frame.
The exposure was carried out by irradiating the image-forming
materials with light of a 500 W xenon lamp for 30 seconds through a
step-wedge (having a density difference in step of 0.15 and 1 to 15
density steps, "FUJI STEPGUIDE P" (manufactured by Fuji Photo film
Co., Ltd.) to thereby form latent images (latent-image forming
step). After the exposure, the image-forming materials having
thereon latent images were each heated for 15 seconds by means of a
hot plate at 120.degree. C. (step in which the image is made
visible).
[0389] Color was not developed in the region of the exposed
portions irradiated with light of high intensity and the density of
developed color dropped in the region of the exposed portions
irradiated with light of low intensity. Among the steps where color
was not developed, the step number of the step-wedge corresponding
to the step of the smallest exposure amount (i.e., clear step
number) was determined. The higher the clear step number, the
higher the sensitivity of the image-forming material. The results
of the clear step number and the results of the saturated density
(Dmax) measurements in unexposed portions [measured by Macbeth
reflection densitometer (RD918)] are shown in Table 3.
3 TABLE 3 Clear step number Dmax Example 12 10 2.1 Example 13 9 2.0
Example 14 10 2.1 Example 15 10 2.1 Example 16 9 2.0
Comparative Examples 12 to 16
[0390] When the entire surface of each of the image-forming
materials of Examples 12 to 16 was heated for 15 seconds at
120.degree. C. without exposure to light, color was developed in
the entire surface. Accordingly, in these embodiment, it is
understood that the image-wise exposure is necessary before heating
the entire surface.
Example 17
[0391] The image-forming material of Example 17 was obtained in the
same way as in Example 4, except that the acid emulsion (2) in
Example 4 was replaced by the acid emulsion (5) (the concentration
was adjusted based on the acid).
Example 18
[0392] The image-forming material of Example 18 was obtained in the
same way as in Example 17, except that the acid emulsion (5) in
Example 17 was replaced by the acid emulsion (6) (the concentration
was adjusted based on the acid).
Example 19
[0393] The image-forming material of Example 19 was obtained in the
same way as in Example 5, except that the acid emulsion (2) in
Example 5 was replaced by the base emulsion (3) (the concentration
was adjusted based on the base).
Example 20
[0394] The image-forming material of Example 20 was obtained in the
same way as in Example 9, except that the oxidizing agent emulsion
(1) in Example 9 was replaced by the oxidizing agent emulsion (3)
(the concentration was adjusted based on the oxidizing agent).
Example 21
[0395] The image-forming material of Example 21 was obtained in the
same way as in Example 7, except that the acid emulsion (2) in
Example 7 was replaced by the alkylating agent emulsion (3) (the
concentration was adjusted based on the alkylating agent).
[0396] (Image formation using the image-forming materials of
Examples 17 to 21 and assessment thereof)
[0397] The image-forming materials of Examples 17 to 21 were each
subjected to step-wedge-wise exposure by using a 650 nm
semiconductor laser, wherein the irradiation energy was varied so
that the maximum irradiation energy became 15 mJ/cm.sup.2 by
changing the scanning speed (latent-image forming step).
[0398] When the entire surface of the image-forming layer of each
of the image-forming materials having thereon latent images was
heated for 15 seconds by means of a hot plate at 120.degree. C.,
the image-forming materials of Examples 17 to 20 developed a
magenta color and the image-forming material of Example 21
developed a cyan color. Thus, step-wedge images were obtained (step
in which the image is made visible).
[0399] The entire surface of the image-forming layer of each of the
image-forming materials of Examples 17 to 21 having thereon images
formed was irradiated with light for 30 seconds on a high-intensity
schaukasten of 58000 lux. Since this treatment fixed the entire
surface of images and decolorized the dye of the
photopolymerization initiator by the decomposition thereof, images
whose background had a higher level of whiteness were obtained
(fixing step).
[0400] The saturated density (Dmax) of the image portions and the
fogging (Dmin) of the non-image portions (background) of the images
thus fixed were measured by Macbeth reflection densitometer
(RD918). In addition, at a step, corresponding to the same exposure
amount, within the step-wedge images of the image-forming
materials, the energy difference between the irradiated energy at
the latent-image forming step at that step and the irradiated
energy required until the background of the image-forming materials
was formed at the fixing step (i.e., "the irradiated energy
required until the background was formed at the fixing step"--"the
irradiated energy at the latent-image forming step at that step")
was measured and calculated. This value was used as an indicator of
sensitivity. The smaller the value, the higher the sensitivity. The
results of the sensitivity, Dmax, and Dmin are shown in Table
4.
4 TABLE 4 Sensitivity Dmin (mJ/cm.sup.2) Dmax (Fogging of
background) Example 17 1.2 1.8 0.06 Example 18 1.5 1.7 0.07 Example
19 1.2 1.9 0.06 Example 20 1.3 1.8 0.06 Example 21 1.3 1.8 0.07
[0401] Furthermore, the images of the image-forming materials
obtained were subjected to irradiation at 0.9 W/m.sup.2 for 48
hours in WEATHER-O-METER CI65 (manufactured by Atlas Electric
Devices Corp.) for the purpose of assessing the lightfastness. As
an indicator of the lightfastness, the ratio of the image density B
after 48 hours, irradiation with light to the fresh image density A
(B/A.times.100%) was used. The results are shown in Table 5.
5 TABLE 5 Lightfastness (B/AX 100)[%] Example 17 91 Example 18 91
Example 19 93 Example 20 90 Example 21 95
[0402] As shown in Table 5, almost no fading was observed.
Comparative Example 17
[0403] The image-forming material of Comparative Example 17 was
obtained in the same way as in Example 18, except that the
microcapsule dispersion liquid (3) in Example 18 was replaced by
the microcapsule dispersion liquid for comparison (11) (the
concentration was adjusted based on the dye precursor).
Comparative Example 18
[0404] The image-forming material of Comparative Example 18 was
obtained in the same way as in Example 19, except that the
microcapsule dispersion liquid (4) in Example 19 was replaced by
the microcapsule dispersion liquid for comparison (9) (the
concentration was adjusted based on the dye precursor).
Comparative Example 19
[0405] The image-forming material of Comparative Example 19 was
obtained in the same way as in Example 20, except that the
microcapsule dispersion liquid (1) in Example 20 was replaced by
the microcapsule dispersion liquid for comparison (8) (the
concentration was adjusted based on the dye precursor).
Comparative Example 20
[0406] The image-forming material of Comparative Example 20 was
obtained in the same way as in Example 21, except that the
microcapsule dispersion liquid (6) in Example 20 was replaced by
the microcapsule dispersion liquid for comparison (10) (the
concentration was adjusted based on the dye precursor).
[0407] (Image formation using the image-forming materials of
Comparative Examples 17 to 20 and assessment thereof)
[0408] The image-forming materials of Comparative Examples 17 to 20
thus obtained were each subjected to the same treatments as in the
latent-image forming step and step in which the image is made
visible as those described in the section entitled "Image formation
using the image-forming materials of Examples 17 to 21 and
assessment thereof". The results of the measurement of the
saturated density (Dmax) are shown in Table 6.
6 TABLE 6 Dmax Comparative Example 17 0.55 Comparative Example 18
0.12 Comparative Example 19 0.13 Comparative Example 20 0.72
[0409] As can be seen from Table 6, the densities of the developed
color were lower relative to the case where the compounds of the
present invention were used.
Example 22
[0410] The image-forming material of Example 22 was obtained in the
same way as in Example 1, except that the microcapsule dispersion
liquid (1) in Example 1 was replaced by the microcapsule dispersion
liquid (7).
[0411] (Image formation using the image-forming material of Example
22 and assessment thereof)
[0412] The image-forming material of Example 22 thus obtained was
subjected to the same treatment of the latent-image forming step as
that described in the section entitled "Image formation using the
image-forming materials of Examples 12 to 16 and assessment
thereof". In this way, a latent image was formed by exposure to a
xenon lamp. Next, the image-forming material having thereon the
latent image was passed through pressing rollers at a line pressure
of 100 kg/cm to make the image visible (step in which the image is
made visible). In this step, the microcapsules exposed to a larger
amount of light in the latent-image forming step were not broken
but the microcapsules exposed to a smaller amount of light in the
latent-image forming step were broken. In this way, a step-wedge
image in accordance with the latent image was formed.
[0413] Further, the whole image-forming layer of the image-forming
material was exposed to light in the same way of fixing step as
that described in the section entitled "Image formation using the
image-forming materials of Examples 17 to 21 and assessment
thereof" so as to bleach the dye used in the polymerization
initiator. In this way, the image whose background had a higher
level of whiteness was obtained.
Example 23
[0414] 1) Preparation of a Liquid For Coating a Cyan-color
Developing Image-forming Layer
[0415] A liquid for coating an image-forming layer was prepared in
the same way as in Example 18, except the microcapsule dispersion
liquid (3) in Example 18 was replaced by the microcapsule
dispersion liquid (5). The liquid thus prepared was used as the
liquid for coating a cyan-color developing image-forming layer.
[0416] 2) Preparation of a Liquid For Coating a Magenta-color
Developing Image-forming Layer
[0417] A liquid for coating an image-forming layer was prepared in
the same way as in Example 18, except the acid emulsion (6) in
Example 18 was replaced by the acid emulsion (7). The liquid thus
prepared was used as the liquid for coating a magenta-color
developing image-forming layer.
[0418] 3) Preparation of a Liquid For Coating an Interlayer
[0419] A liquid for coating an interlayer was prepared by mixing
4.5 g of a 15% gelatin aqueous solution, 4.5 g of distilled water,
and 0.3 g of a 2% aqueous solution of the following surfactant.
48
[0420] As shown in FIG. 1, a support 1 for print paper, which was
prepared by laminating polyethylene on a sheet of fine paper, was
coated successively with the above-described liquid for coating a
cyan-color developing image-forming layer (layer A 2), liquid for
coating an interlayer 3, and liquid for coating a magenta-color
developing image-forming layer (layer B 4) in such a manner that
the dry coating weight of each image-forming layer became 6
g/m.sup.2, and the dry coating weight of the interlayer became 1.5
g/m.sup.2. The coating layers were dried successively and an
image-forming layer was obtained. Next, the liquid for coating a
protective layer 5 was applied onto the image-forming layer in such
a manner that the dry coating weight of the protective layer became
2 g/m.sup.2, and the coating layer was dried. In this way, the
image-forming material of Example 23 was obtained.
[0421] The image-forming material of Example 23 was irradiated
image-wise with a semiconductor laser having a wavelength of 650 nm
and with a fixed laser having a wavelength of 532 nm from the
protective layer side so that the maximum irradiation energy of
each laser became 15 mJ/cm.sup.2 to thereby form a latent image
(latent-image forming step). The entire surface of the
image-forming layer of the image-forming material having thereon
latent images was heated for 10 seconds by means of a hot plate at
105.degree. C. (step in which the image is made visible) After
that, the entire surface of the image-forming layer of the
image-forming material was irradiated with light for 30 seconds on
a high-intensity schaukasten of 58000 lux (fixing step). As a
result of this treatment, a vividly colored image with background
having a high level of whiteness was obtained. The lightfastness
and heat resistance of the image obtained was good.
[0422] According to the present invention, it is possible to
provide an azomethine dye precursor that is a useful novel
compound. More specifically, it is possible to provide an
azomethine dye precursor which develops color by the action of a
deblocking agent or by the action of heat and a deblocking agent
and which, when used in the image-forming layer of an image-forming
material, exhibits good color development by a small amount of
energy and provides images having very good durability.
[0423] Also, according to the present invention, it is possible to
provide a single-color or multicolor image-forming material capable
of utilizing a variety of light sources emitting light of
wavelengths ranging from ultraviolet to near infrared and capable
of speedily forming high-quality and highly durable images with a
high-sensitivity in a perfectly dry processing system, which does
not require a developing solution or the like and does not produce
wastes, and to provide an image forming method using the
image-forming material.
* * * * *