U.S. patent number 3,885,081 [Application Number 05/331,349] was granted by the patent office on 1975-05-20 for sheet material.
This patent grant is currently assigned to Agfa-Gevaert, N.V.. Invention is credited to Jan Jozef Priem, Lucien Janbaptist Van Gossum, August Jean Van Paesschen.
United States Patent |
3,885,081 |
Van Paesschen , et
al. |
May 20, 1975 |
Sheet material
Abstract
Improved adherence is obtained for sheet material having a
hydrophobic film support or base, such as a hydrophobic cellulose
ester or poly ester, by the combination of a vinyl polymer subbing
layer arranged directly on the hydrophobic support, the subbing
layer being formed of a copolymer containing at least 45 percent by
weight of vinylidene chloride and/or vinyl chloride monomer along
with a minor amount of a hydrophilic vinyl monomer with the balance
being constituted by any other vinyl monomer, and superimposed upon
the vinyl subbing layer a layer containing a mixture of gelatin
with a copolymer of butadiene and a vinyl monomer containing 30-70
percent by weight of butadiene, the ratio of the gelatin to the
butadiene copolymer being in the range of 1:3 to 2:1 by weight. An
additional layer can be applied over the gelatin/copolymer layer
and constituted by such ingredients as are desirable for the
particular utility of the resultant sheet material, such as
electrophotographic layers containing finely divided
photoconductive material such as zinc oxide or some other
photosensitive semi-conductive material, mat layers containing
pigment, diffusion transfer layers containing development nuclei
and so on. Alternatively, the ingredients appropriate to some
particular ultimate utility can be incorporated into the
gelatin/butadiene copolymer layer directly.
Inventors: |
Van Paesschen; August Jean
(Antwerpen, BE), Van Gossum; Lucien Janbaptist
(Kontich, BE), Priem; Jan Jozef (Mortsel,
BE) |
Assignee: |
Agfa-Gevaert, N.V. (Mortsel,
BE)
|
Family
ID: |
26265330 |
Appl.
No.: |
05/331,349 |
Filed: |
February 12, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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165312 |
Jul 23, 1971 |
3788856 |
|
|
|
763382 |
Sep 27, 1968 |
3649336 |
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Foreign Application Priority Data
|
|
|
|
|
Aug 12, 1968 [GB] |
|
|
44114/68 |
|
Current U.S.
Class: |
428/475.8;
428/476.1; 428/483; 430/60; 430/158; 430/227; 430/536; 430/539;
430/271.1 |
Current CPC
Class: |
G03G
5/0571 (20130101); G03C 8/52 (20130101); G03C
1/93 (20130101); G03G 5/087 (20130101); G03G
5/14 (20130101); G03G 5/10 (20130101); G03C
1/95 (20130101); G03G 5/0553 (20130101); G03C
1/89 (20130101); Y10T 428/31746 (20150401); Y10T
428/31743 (20150401); Y10T 428/31797 (20150401) |
Current International
Class: |
G03G
5/10 (20060101); G03C 8/52 (20060101); G03G
5/05 (20060101); G03G 5/087 (20060101); G03C
1/93 (20060101); G03C 1/95 (20060101); G03G
5/14 (20060101); G03C 1/89 (20060101); G03C
1/91 (20060101); G03C 8/00 (20060101); B44d
001/18 (); G03c 001/80 () |
Field of
Search: |
;117/218,76F,83
;96/1.5,87R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Husack; Ralph
Attorney, Agent or Firm: Daniel; William J.
Parent Case Text
This is a division of Ser. No. 165,312, filed July 23, 1971 now
U.S. Pat. No. 3,788,856, which Ser. No. 763,382 filed Sept. 27,
1968. now U.S. Pat. No. 3,649,336.
Claims
We claim:
1. Sheet material comprising a hydrophobic film support, a first
layer directly adherent to said hydrophobic film support and
comprising a copolymer formed from 45 to 99.5percent by weight of
at least one vinylidene chloride or vinyl chloride monomer, from
0.5 to 10percent by weight of an ethylenically unsaturated
hydrophilic monomer, and from 0 to 54.5percent by weight of at
least one other copolymerizable ethylenically unsaturated monomer;
a second layer adjacent said first layer comprising in a ratio of
1:3 to 1:0:5percent by weight a mixture of gelatin and a copolymer
of 30 to 70percent by weight of butadiene with at least one
copolymerizable ethylenically unsaturated monomer; and in exterior
relation to said second layer in successive order a hydrophilic
electroconductive layer and electrically insulating layer.
Description
This invention relates to sheet material which comprises a
hydrophobic support film and a layer system which is capable, if so
desired, of providing a bond between a hydrophilic layer and the
said hydrophobic support film, or which may itself provide a
vehicle for light-sensitive material as hereinafter described, and
particularly relates to film recording materials, films and foils
consisting of or comprising said sheet material.
In the following description and claims the terms "photographic
film elements" and "film recording materials" include elements and
materials for use in a variety of photo-reproduction systems.
Examples of such systems include the well-known use of
light-sensitive silver halide emulsions, electrographic and
electrophotographic systems, and a recently developed
photosensitive system wherein the recording is effected by means of
photosensitive semi-conductive substances.
In the said recently developed photosensitive systems, images are
produced by the action of electromagnetic radiation on
photosensitive semi-conductor compounds, compositions or materials,
which are reversibly activated by patterns of radiations to create
a latent image of corresponding activated patterns. The latent
image is capable of producing a chemical reaction with a dissolved
reactant by an oxidation-reduction chemical process to form a
visible image (see "Unconventional Photographic Systems,"Second
Symposium, Oct. 26-28, 1967, Washington D.C., pages 116-117).
In electrographic systems, electrostatic charges are applied
information-wise to an insulating surface. In such process an
electrostatic charge pattern is built up on an insulating layer
e.g., by means of a modulated electron beam while a conductive
element e.g., a conductive support or layer stands in electrical
contact with the back side of said insulating layer, to which a
voltage is applied. After the pattern-wise charging of the
insulating layer, the electrostatic charge pattern is developed,
for instance by the application of a powder. Before powder
development, the conductive backing element may be removed if
desired. An alternative development technique is to bring about an
image-wise deformation (ripple image) of the insulating layer as
hereinafter described.
In electrophotographic systems, the recording of images is based on
a differentiation in electrostatic charge condition, chargeability
or electrical conductivity, of a recording layer containing a
photoconductive substance, the said layer initially being
electrically insulating in the absence of light, but becoming
electrically conductive on exposure to light, and being in
electrical contact with an electroconductive support or layer. By
image-wise exposing the recording layer to image-wise modulated
activating electromagnetic radiation, a pattern of the said
differential charge condition is obtained. The electrostatic charge
images may be developed by an electrostatically attractable marking
material, or the conductivity images by electrolysis.
A particular technique of developing the latent image on a
recording layer from either an electrographic or an
electrophotographic process involves the deformation of the exposed
areas to produce a so-called "ripple image,"by image-wise
distortion of the surface under the influence of a differential
electrical potential between the recording element and the backing
element, and reference may be made to United Kingdom Pat.
specification No. 964,881 to "Photographic Science and
Engineering,"Vol. 7, No. 1 (1963) pages 12-13; to RCA Review, Dec.
1964, pages 692-709, and to United Kingdom Pat. application No.
5307/66, now British Pat. No. 1,445,153.
In the manufacture of photographic film elements for use in silver
halide emulsion layer systems, it is common practice to apply to
the film support before the light-sensitive silver halide emulsion
layer or other colloid layers are applied, a thin subbing layer
consisting mainly of gelatin. If such a subbing layer is omitted,
the photographic emulsion layer or the other colloid layers will
not adhere sufficiently to the base.
The invention consists of a hydrophobic support film carrying
superposed thereon in succession, a layer (A) which is directly
adherent to the said hydrophobic support film and comprises a
copolymer formed from 45 to 99.5 percent by weight of at least one
of the chlorine-containing monomers vinylidene chloride and vinyl
chloride, from 0.5 to 10 percent by weight of an ethylenically
unsaturated hydrophilic monomer, and from 0 to 54.5 percent by
weight of at least one other copolymerisable ethylenically
unsaturated monomer; and a layer (B) comprising in a ratio of 1:3
to 1.0.5 by weight of a mixture of gelatin and a copolymer of 30 to
70 percent by weight of butadiene with at least one copolymerisable
ethylenically unsaturated monomer.
Hydrophobic support films suitable for use in the sheet material
according to the invention, include for example a hydrophobic
cellulose ester, e.g. cellulose acetate, cellulose aceto-butyrate
and cellulose nitrate; or a highly polymeric linear polyester such
as for example polyethylene terephthalate, polystyrene or
polymethacrylic acid esters. Such hydrophobic support films are
coated with successive layers (A) and (B) according to the
invention to provide a layer system which may be used for a variety
of purposes. Thus the sheet material may be used for the
transference thereto of a hydrophilic layer. Thus in recording or
reproduction systems such a hydrophilic layer may be a stripped-off
hydrophilic layer carrying a relief pattern. The sheet material
according to the invention may be wetted with a liquid system
capable of providing a hydrophilic film thereon. Thus the sheet
material according to the invention may contain in the said layer
(B) photosensitive semiconductor compounds, compositions or
materials which are reversibly activated by patterns of radiations
to create a latent image, and the said liquid system may then be an
aqueous developing solution for the development of such a latent
image.
As described a hydrophilic layer may be applied to layer (B) of the
sheet material according to the invention which hydrophilic layer
may be for example either transferred from another material or
produced thereon from a liquid system. Both layer (B) and the
hydrophilic layer when present, amy contain one or more other
substances, e.g. as follows:
a. semi-conductive substance(s) in a suitable binding agent
b. electro-conductive agent(s) in a suitable binding agent
c. pigment(s) in a photohardenable or photosolubilizable binder
d. matting agent(s) or opaque white pigment(s) in a suitable
binder
e. light-sensitive substance(s) including light-sensitive silver
halide, photoconductive substances, and other light-sensitive
compounds, e.g. diazonium salts and diazo-sulphonates
f. dissolved dye(s) e.g. a dye that is bleachable
g. colour coupler(s) e.g. a colour coupler that is used in silver
halide colour photography
h. developing nuclei suited in the production of silver images
according to the silver halide complex diffusion transfer
process.
The sheet material according to the invention may be used as a
wrapping material, particularly when having layers thereon
particularly adapted to accept printing thereon, or the sheet
material may be used as tracing film.
Particularly useful recording materials are provided by sheet
material according to the invention, having hydrophilic pigment
coatings thereon, e.g. pigmented gelatin coatings suited for the
production of relief images, which are produced by means of a
photo-hardening or photo-solubilizing reaction. Such pigment
coatings are of practical interest in the graphic art more
particularly in the field known as "colour proofing."Colour
proofing materials serve to form a showing proof for submission for
approval, whereby an idea may be obtained of the multicolour
halftone reproduction which will finally be produced by the
successive printing in register with separate standard inks yellow,
magenta, cyan and black.
For ease of reference, the layer formed from the copolymer of
vinylidene chloride and/or vinyl chloride is hereinafter referred
to as the "vinylidene chloride copolymer" layer, and the layer
formed with the mixture of gelatin and butadiene copolymer is
hereinafter referred to as the "butadiene copolymer" layer.
The vinylidene chloride copolymer comprises from 0.5 to 10 percent
by weight of ethylenically unsaturated hydrophilic monomeric units.
These units may be derived from ethylenically unsaturated mono- or
dicarboxylic acids such as acrylic acid, methacrylic acid, and
itaconic acid. Other hydrophilic units, e.g. those derived from
N-vinyl pyrrolidone, may be present.
The vinylidene chloride copolymer may be formed from vinylidene
chloride and/or vinyl chloride and hydrophilic monomeric units
alone in the ratio indicated above. Preferably up to 54.5 percent
by weight of other recurring units, for instance acrylamides,
methacrylamides, acrylic acid esters, methacrylic acid esters,
maleic esters and/or N-alkylmaleimides, may also be present.
Suitable vinylidene chloride copolymers are e.g.:
the copolymer of vinylidene chloride, N-tert.-butylacrylamide,
n-butyl acrylate, and N-vinyl pyrrolidone (70:23:3:4),
the copolymer of vinylidene chloride, N-tert.-butylacrylamide,
n-butyl acrylate, and itaconic acid (70:21:5:2),
the copolymer of vinylidene chloride, N-tert.-butylacrylamide, and
itaconic acid (88:10:2),
the copolymer of vinylidene chloride, n-butylmaleimide, and
itaconic acid (90:8:2),
the copolymer of vinyl chloride, vinylidene chloride, and
methacrylic acid (65:30:5),
the copolymer of vinylidene chloride, vinyl chloride, and itaconic
acid (70:26:4),
the copolymer of vinyl chloride, n-butyl acrylate, and itaconic
acid (66:30:4),
the copolymer of vinylidene chloride, n-butyl acrylate, and
itaconic acid (80:18:2),
the copolymer of vinylidene chloride, methyl acrylate, and itaconic
acid (90:8:2),
the copolymer of vinyl chloride, vinylidene chloride,
N-tert.-butylacrylamide, and itaconic acid (50:30:18:2).
All the ratios given between brackets in the abovementioned
copolymers are ratios by weight.
The above copolymers are only examples of the combinations, which
can be made with the different monomers, and the invention is not
limited at all to the copolymers enumerated.
The different monomers indicated above may be copolymerised
according to various methods. For example, the copolymerisation may
be conducted in aqueous dispersion containing a catalyst and an
activator. Alternatively, polymerisation of the monomeric
components may occur in bulk without added diluent, or the monomers
are allowed to react in appropriate organic solvent reaction
media.
The vinylidene chloride copolymers may be coated on the hydrophobic
film base according to any suitable technique, e.g., by immersion
of the surfaces of the film into a solution of the coating
material. They may also be applied by spray, brush, roller, doctor
blade, air brush, or wiping techniques. The thickness of the dried
layer may vary between 0.3 and 3 .mu. preferably.
Various wetting or dispersing agents may be used when the
vinylidene chloride copolymer layer is applied from an aqueous
dispersion. These dispersions are obtained directly when the
copolymer has been made by an emulsion polymerisation process. When
coating aqueous dispersions of vinylidene chloride copolymer on a
polyethylene terephthalate film support a very strong adherence to
the support is obtained when said dispersions are applied before or
during stretching of the polyethylene terephthalate film. The
aqueous dispersion may be applied to at least one side of the
non-stretched film, but may also be applied to polyethylene
terephthalate film which has been oriented biaixially. The
vinylidene chloride copolymer layer may also be coated on at least
one side of a polyester film, which has been stretched in only one
direction, e.g. longitudinally, whereafter the subbed polyester
film is stretched in a direction perpendicular thereto, in this
case transversally.
Finally, the biaxially oriented coated polyester film is provided
with the second subbing layer of the mixture of gelatin and
butadiene copolymer latex.
The butadiene copolymer comprises 30 to 70 percent by weight of
monomeric butadiene units. The balance is formed by units deriving
from other ethylenically unsaturated hydrophobic monomers, such as
acrylonitrile, styrene, acrylic acid esters, methacrylic acid
esters, and acroleine.
The butadiene copolymer is formed by emulsion polymerisation and
the primary latex obtained is directly mixed with the aqueous
gelatin solutions in such a way that the ratio of gelatin to
butadiene copolymer in the dried layer varies between 1.3 parts and
1:0.5, all parts being by weight. To the mixture known plasticizers
for gelatin such as polyethylene oxides and glycerol may also be
added.
The mixture of aqueous gelatin solution and of butadiene copolymer
latex is coated onto the vinylidene chloride copolymer layer by
known means. The thickness of the dried layer generally varies
between 0.10 and 20 .mu..
The addition of a latex of a copolymer of butadiene and a lower
alkyl ester of acrylic or methacrylic acid to a gelatin-containing
layer of a photographic material has been described already in the
United Kingdom Patent Specification No. 1,053,043. According to
this Patent Specification the butadiene copolymer latex is added to
reduce the brittleness of the gelatin layer, to procure a higher
dimensional stability to the photographic material, wherein it is
used, and to decrease its curling tendency. However, it cannot be
deduced from this Patent Specification that the layer of gelatin
and butadiene copolymer latex combined with a vinylidene chloride
copolymer layer would procure an adequate subbing combination for
any hydrophobic film support, and especially for polyester film
supports.
The subbed film support consists of a hydrophobic film support and
the combination of the two anchoring subbing layers used according
to the invention. As mentioned before the hydrophobic film support
may be a film of cellulose triacetate, of polyethylene
terephthalate, of polycarbonate, of polystyrene, of polymethacrylic
acid ester, etc. The subbed hydrophobic film support may be
provided on only one side or on both sides with the combination of
subbing layers.
A colloid layer may be deposited on the subbed film support thus
obtained. This colloid layer may be a simple gelatin layer, a
gelatin silver halide emulsion layer, a gelatin filter layer, a
gelatin matting layer containing e.g. finely divided silica, an
antistatic layer or an antihalation layer containing a hydrophilic
colloid binding agent. If an antistatic layer is deposited on the
subbed film support, known antistatic agents, e.g. salts, are
dispersed in the colloid binding agent, e.g. gelatin. In the latter
case too, these salts may be added already to the aqueous gelatin
solution, which is to be mixed with the butadiene copolymer for the
formation of the second layer of the subbing layer combination.
In the manufacture of electrophotographic recording materials
containing a hydrophobic electrically insulating film support and a
photoconductive layer containing a photoconductive substance
applied in a binder, normally an electrically insulating binder, it
is necessary to apply between the photoconductive recording layer
and the said support an electrically conductive interlayer having a
conductivity substantially higher than the conductivity in the dark
of the photoconductive recording layer. Such an interlayer
preferably contains a hydrophilic colloid in combination with
antistatic or hygroscopic agents, e.g. those described in the U.S.
Pat. No. 3,148,982, conductive pigments e.g. carbon black and/or
polyionic polymers e.g. those containing quaternized nitrogen atoms
as described in the United Kingdom Patent Specification 950,960.
Good results are obtained with CALGON CONDUCTIVE POLYMER 261
manufactured by Calgon Corporation, Calgon Center Box 1346,
Pittsburgh, U.S.A. (Calgon is a registered Trade Mark). Such
antistatic or electroconductive hydrophilic colloid layers
perfectly adhere to hydrophobic film supports subbed according to
the present invention.
In the manufacture of interesting photochemically recording
materials e.g. as described in the Belgian Patent Specification No.
655,384 and the published Dutch Patent Application No. 6413011,
semiconductive light-sensitive pigments are dispersed in a binder
containing a hydrophilic colloid.
In the manufacture of interesting electrostatic recording materials
e.g. as described in the United Kingdom Patent Application No.
16,459/66 now British Pat. No. 7,756,822 and the published Dutch
Patent Application No. 6,608,815 a n-type photoconductor pigment is
dispersed in a binder having a hydrophilic character.
A hydrophobic film support is firmly bonded to such pigment
coatings by means of the composite subbing layer according to the
present invention.
In all the above described applications of the combination of
subbing layers according to the invention, at least one layer is
deposited on top of the butadiene copolymer layer. The layer
deposited thereon may be a simple hydrophilic colloid layer e.g. a
gelatin layer, a hydrophilic colloid layer containing
light-sensitive silver halide salts, a hydrophilic polymer or
colloid layer containing all kinds of special additives such as
antihalation dyestuffs, antistatic agents, electroconductive
pigments, photoconductive insulating pigments, photo-sensitive
semiconductive pigments and matting agents. All these additives may
also be added already to the coating composition of the butadiene
copolymer layer. Thus, there can be incorporated into the butadine
copolymer layer finely divided silicium dioxide, photo-sensitive
titanium dioxide, photoconductive zinc oxide and carbon black.
According to a preferred embodiment these additives are dissolved
when they are soluble in the coating composition or homogeneously
dispersed in the mixture of aqueous gelatin solution and butadiene
copolymer latex before casting of the second subbing layer on top
of the vinylidene chloride copolymer layer. When the subbed
hydrophobic film support is to be used as a tracing film support,
there may be added to the butadiene copolymer layer, which already
contains a white pigment e.g. titanium dioxide and/or silicium
dioxide, also urea-formaldehyde or melamine-formaldehyde resins to
render the surface of the layer more resistant to writing and
tracing operations.
In a particular embodiment of the invention a n-type
photoconductive substance e.g. photoconductive zinc oxide is
dispersed in the butadiene copolymer layer and no further radiation
sensitive layers are deposited on top of the said layer. In this
way a photographic material is produced, which is suited for use
according to the process described in the United Kingdon Patent
Application No. 16,459/66, now British Pat. No. 7,756,822.
According to a special and very interesting embodiment of the
invention a photo-sensitive semiconductor material is dispersed in
the butadiene copolymer layer and no further radiation-sensitive
layers are deposited on top of the said layer. In this way a
photographic recording material is obtained by which visible or
latent images can be formed in the absence of an externally applied
electric field by means of the image-wise modulated action of
electromagnetic radiation reversibly activating the photo-sensitive
semiconductor material in such a way that by means of a dissolved
reactant, a portion of which may be present in the recording
material before the exposure, images corresponding to the
light-activated pattern are produced by an oxidation-reduction
reaction, the said photosensitive semiconductor itself being
substantially chemically unchanged at the end of the process. So,
the recording material according to the present invention is
composed of a hydrophobic film support coated with the vinylidene
chloride copolymer layer and having thereon the butadiene copolymer
layer, in which the photosensitive semiconductor material is
dispersed. Photo-sensitive semiconductor compounds suited for use
in process for producing visible or latent images by an
oxidation-reduction reaction as indicated above are described e.g.
in the United kingdom Patent Specification No. 1,043,250, which
pertains to a related process. Titanium dioxide is of special
interest as semiconductor material, but other known semiconductors,
which become conductive on irradiation, can also be used e.g. zinc
oxide, zinc sulphide, lead monoxide, red lead oxide, silicium
dioxide, aluminium dioxide, chromium oxide, osmium oxide, and
cadmium sulphide.
In the said process the average particle size of the finely divided
semiconductors is important. Particle sizes not larger than 250
millimicrons and preferably comprised between 5 and 100
millimicrons are very advantageous.
The finely divided semiconductor is dispersed in the above
described binder material consisting of gelatin and butadiene
copolymer in such a proportion that in the dried layer the ratio of
binding agent to semiconductor varies between 3:1 and 1:10 by
weight. The thickness of the radiation-sensitive coating applied on
the vinylidene chloride copolymer layer by known means should be
generally situated between 0.10 and 20 .mu. after drying.
Activation of the semiconductor surfaces is effected by exposure to
radiation of sufficient energy. Ultraviolet radiation having a
wavelength of less than approximately 4,000 A is very appropriate.
However sensitization of the semiconductors e.g. by doping with
foreign ions or dye sensitization techniques can be employed to
make the semiconductor sensitive to radiation in the visible
spectrum.
Exposure to a suitable source of radiation modified by an image
pattern establishes gradients of differential chemical reactivity
between the exposed and non-exposed portions and establishes an
image pattern in the exposed portions of the semiconductor
material. Said image pattern is reversible and can be erased
therefrom, e.g. by heating. It can also be made permanent by
bringing the activated portions in contact with suitable oxidising
or reducing agents according to known techniques. This reaction
forms a visible image pattern.
The reversible image, which was obtained upon exposure to a source
of radiation need not be treated with the oxidising or reducing
agents directly after exposure. It can be stored for a certain time
and at a later stage it can be erased or developed to produce
either positive or negative images corresponding with the image
stored in the exposed semiconductor. After development, the
semiconductor surface is thoroughly washed to remove any remaining
developer, whereupon the semiconductor surface can be reused if new
information should be added to the already developed image. For
development, numerous developers including silver ions, can be
employed.
If the degree of semiconductor activation is high, the quantity of
e.g. metallic silver formed by reduction of silver ions by the
light-activated photoconductor will be sufficient to form a visible
image directly. If not so, a latent developed image is produced in
the semiconductor. Such a image is irreversible and can be stored
for long periods. It can also be intensified by an image
intensification development according to which e.g. solutions
containing substances such as univalent silver ions, mercurous
ions, and mercuric ions, which are reducible by the light-activated
semiconductor to finely divided black-appearing metallic silver or
mercury, are used in combination with chemical redox systems,
preferably organic redox systems such as those containing
hydroquinone or p-monomethylamino-phenol sulphate.
After development the semiconductor surfaces are rendered incapable
of further development by thorougly washing e.g. in water
containing a solubilizing or complexing agent to aid removal of
residual developer. In an analogous manner as in the fixing
solutions employed in silver halide photography, such solutions
solubilize the remaining developer e.g. silver ion, and they
facilitate the removal thereof by washing.
In contradistinction with the above-described process for forming
an irreversible image in a semiconductive layer, it is also
possible to soak the semiconductive layer before the exposure with
a solution of the developer. In this way there is immediately
obtained an irreversible image upon exposure.
When hydrophobic film e.g. polyester film was used as the support
for the radiation-sensitive semiconductor coating, at least two
subbing layers were needed hitherto, to obtain a sufficient
adhesion between the semiconductor coating and the support. The
possibility of incorporating the photosensitive semiconductive
substances in one of the subbing layers offers the considerable
advantage, that but two subbing layers must be applied. With these
two subbing layers the adhesion as well as the photographic
properties are excellent.
The following examples illustrate the present invention.
EXAMPLE 1
In a reaction flask equipped with a stirrer, a nitrogen inlet, a
dropping funnel, and a condenser were placed 10 litres of water and
2.88 litres of a 10 percent aqueous solution of the sodium salt of
sulphonated dodecyl benzene. Then the reaction flask was rinsed
with nitrogen and the liquid was heated to 60.degree.C. In another
flask were placed successively 800 ccs of isopropanol, 144 g of
N-vinyl-pyrrolidone, 108 g of n-butyl acrylate, 830 g of
N1tert.-butylacrylamide and 2,520 g of vinylidene chloride. The
mixture was stirred and brought to dissolution by gentle
heating.
Through the dropping funnel a solution was added of 21.6 g of
ammonium persulphate in 400 ccs of water. Immediately pumping of
the monomer solution into the reaction flask was started. the rate
of pumping was such that after 75 min. all the monomer solution was
pumped over. Together with the monomer solution a further amount of
ammonium persulphate solution was added dropwise (64.8 g in 1,200
ccs of water). During the whole reaction period the temperature of
the mixture was maintained at 60.degree. C while refluxing. After
all the monomer had been added, again an amount of 21.6 g of
ammonium persulphate dissolved in 400 ccs of water was added at
once. After refluxing, stirring was continued for another 30 min.
at 60.degree.C, whereupon the reaction mixture was cooled to room
temperature.
In order to precipitate the copolymer of vinylidene chloride,
N-tert.-butylacrylamide, n-butyl acrylate, and n-vinylpyrrolidone
(70:23:3:4), the latex formed was poured into a mixture of 40
litres of 10 percent aqueous sodium chloride solution and 40 litres
of methanol while stirring. The fine grainy precipitate which was
obtained was repeatedly washed with water and finally dried.
An amount of 2.5 g of the vinylidene chloride copolymer formed
above were dissolved in a mixture of 90 ccs of butanone and 10 ccs
of nitroethane. The solution obtained was warmed to 25.degree. C
and coated on a plate of polymethyl methacrylate in such a way that
0.75 to 1.0 g of copolymer was present per sq.m. This layer was
dried at room temperature.
To the subbing layer obtained a second layer was applied at
35.degree. to 50.degree. C in a ratio of 0.4 to 0.6 g/sq.m from the
following composition:
20 % latex of copolymer of butadiene and methyl methacrylate
prepared as described hereinafter 10 g gelatin 1 g water 55 ccs
acetone 40 ccs methyl glycol 5 ccs
After drying, a light-sensitive gelatin silver halide emulsion
layer as commonly used in the graphic art was applied to this
layer. The layers of the photographic material manufactured in this
way showed a good adherence before, during as well as after
processing in the photographic baths.
The copolymer latex was prepared as follows:
In a 20 litres autoclave were placed successively: ,191
After sealing of the autoclave, the strongly stirred emulsion was
polymerised for 6 h at 60.degree.C. This polymerisation was
slightly exothermic for a short while. Then the pressure dropped
rapidly. The polymerisation was finished under reduced pressure.
The latex of the copolymer of butadiene and methyl methacrylate
(50:50) was then freed from residual traces of monomer by blowing
at 60.degree.C and under a slight vacuum an air current above the
latex. Then the latex was cooled and filtered.
EXAMPLE 2
To a cellulose triacetate film a layer was applied at a ratio of
0.75 to 1 g/sq.m from the following composition at 25.degree.C:
copolymer of vinylidene chloride, N-tert.-butyl-acrylamide, n-butyl
acrylate, and N-vinyl pyrrolidone of example 1 2 g acetone 50 ccs
ethyl acetate 10 ccs methanol 10 ccs ethanol 10 ccs butanone 10
ccs
A second layer was applied to the resulting dried layer in a ratio
of 0.4 to 0.6 g/sq.m at 35.degree.-50.degree.C from the following
composition:
A light-sensitive gelatin silver halide emulsion layer was coated
thereon.
The layers of the photographic material thus obtained possessed an
excellent adherence in wet as well as in dry state.
EXAMPLE 3
In an autoclave were placed 1,650 ccs of water and 9.6 g of
itaconic acid. After dissolution a solution of 6 g of sodium
hydrogen carbonate in 120 ccs of water was added. Subsequently 98
ccs of a 10 percent aqueous solution of the disodium salt of
disulphonated dodecyl diphenyl ether and 49 ccs of a 10 percent
aqueous solution of the sodium salt of sulphonated dodecyl benzene
were added as emulsifying agents. Then 96 g of n-butyl acrylate,
144 g of vinylidene chloride, 9.8 g of ammonium persulphate, and
4.9 g of potassium metabisulphite were added. The autoclave was
sealed and stirring started. Under nitrogen pressure 240 g of vinyl
chloride were pressed into the autoclave, which was then heated to
50.degree.C, while stirring. When this temperature had been
reached, stirring was continued for 15 to 30 min. The temperature
of the latex rose to about 65.degree.C. The reaction was continued
for about 3 h whereupon the latex was cooled to room temperature.
The pH thereof amounted to 2.6 and was brought to 6 by means of 100
ccs of 1N aqueous sodium hydroxide. It was very well filtrable and
consisted of the copolymer of vinylidene chloride, vinyl chloride,
n-butyl acrylate, and itaconic acid (30:50 18:2) in a concentration
of 20 percent.
To an extruded polyethylene terephthalate film, which had been
stretched longitudinally up to 3 times its original length, a
subbing layer was applied in a ratio of about 2 g/sq.m from an
aqueous suspension containing:
20 % latex of copolymer of vinylidene chloride, vinyl chloride,
n-butyl acrylate and itaconic acid (30:50:18:2) (manufactured as
above) 500 g finely divided silica 5 g
The film coated in this way was then stretched transversely up to 3
times its original width, whereupon a second subbing layer was
applied in a ratio of 0.4 to 0.6 g/sq.m at 35.degree.-50.degree. C
from the following composition:
20 % latex of copolymer of butadiene and methyl methacrylate of
example 1 7.5 g gelatin 1 g water 60 ccs methanol 40 ccs
This subbed film was provided with a light-sensitive gelatin silver
halide emulsion layer as commonly used for graphic purposes. The
layers of photographic material thus obtained possessed a good
adherence before as well as after processing.
EXAMPLE 4
To one side of a biaxially oriented polyethylene terephthalate film
of 180 .mu. thickness a layer was applied at 25.degree.-30.degree.
C in a ratio of 1.5 to 1.75 g/sq.m from the following
composition:
copolymer of vinylidene chloride, N-tert.-butyl-acrylamide, n-butyl
acrylate, and N-vinyl pyrrolidone of example 1 5.5 g methylene
chloride 65 ccs dichloroethane 35 ccs
After drying of the first layer, a second layer was applied thereto
in a proportion of 0.4 g/sq.m from the following composition:
20 % latex of copolymer of butadiene and methyl methacrylate of
example 1 6.25 g gelatin 1 g water 43 ccs silica 0.5 g polystyrene
sulphonic acid 1.8 g methanol 40 ccs
A gelatin silver halide emulsion layer as used in photographic
X-ray material was then coated on this antistatic layer. The layers
of the photographic material thus obtained possessed a good
adherence in all circumstances.
EXAMPLE 5
To both sides of a biaxially oriented polyethylene terephthalate
film of 100 .mu. thickness a layer was applied from the following
composition at 25.degree.-30.degree.C:
copolymer of vinylidene chloride, N-tert.-butylacrylamide, n-butyl
acrylate, and itaconic acid (70:21.5:4) prepared analogously to the
vinylidene chloride copolymer of example 1 7 g methylene chloride
65 ccs dichloroethane 35 ccs
This coating composition was applied in such a way that the dried
layer had a thickness of 1.5 to 1.75 .mu.. To both subbing layers a
layer was applied in a proportion of 0.4 to 0.6 g/sq.m from the
following composition at 35.degree.-50.degree.C:
20 % latex of copolymer of butadiene and styrene (60:40) prepared
ana- logously to the latex of the copoly- mer of butadiene of
example 1 5 g gelatin 1 g water 60 ccs methanol 40 ccs
A light-sensitive gelatin silver halide emulsion layer as commonly
used in the graphic art was applied to one of the coated sides of
the resulting dry material. An antihalation layer of gelatin and
manganese dioxide was coated on the back-side of the material. The
layers of the photographic material thus obtained showed a very
good adherence in wet as well as in dry state.
EXAMPLE 6
Example 5 was repeated, with the difference, however, that the
coating composition for the second subbing layer was replaced by
the following one:
20 % latex of copolymer of butadiene and ethyl acrylate (50/50)
6.25 g gelatin 1 g water 60 ccs ethanol 40 ccs
The adherence of the layers of the material obtained was
excellent.
EXAMPLE 7
Example 5 was repeated, with the difference, however, that the
coating composition of the second subbing layer was replaced by the
following one:
20 % latex of copolymer of butadiene, ethyl acrylate and acrolein
(55:40:5) 6 g gelatin 0.80 g water 60 ccs methanol 40 ccs
The adherence of the layers of the material was excellent.
EXAMPLE 8
Example 5 was repeated, but the coating composition of the second
subbing layer was replaced by the following one:
20 % latex of butadiene and acrylo- nitrile (60:40) 6 g gelatin
0.80 g water 60 ccs methanol 40 ccs
The adherence of the layers of the material obtained was
excellent.
EXAMPLE 9
Example 5 was repeated, but the coating composition of the second
subbing layer was replaced by the following one:
20 % latex of copolymer of butadiene and ethyl hexyl acrylate
(60:40) 6 g gelatin 0.80 g water 60 ccs methanol 40 ccs
The adherence of the layers of the material obtained was
excellent.
EXAMPLE 10
To a biaxially oriented polyethylene terephthalate film of 180 .mu.
thickness a layer was applied at 25.degree. C in a proportion of 2
g/sq.m from the following composition:
copolymer of vinyl chloride, n-butyl acrylate, and methacrylic acid
(70:26:4) 8 g methylene chloride 80 ccs dichloroethane 20 ccs
A second layer was applied thereto at 25.degree. C in a proportion
of 0.6 g per sq.m from the following coating composition:
20 % latex of copolymer of butadiene and ethyl acrylate (50:50)
6.25 g gelatin 1 g water 60 ccs methanol 40 ccs
The dried combination of subbing layers was coated successively
with an antistatic gelatin layer and a light-sensitive gelatin
silver halide emulsion layer as commonly used in X-ray photographic
material. The layers of the material thus obtained showed an
excellent adherence before, during as well as after processing.
EXAMPLE 11
To a biaxially oriented polyethylene terephthalate film of 180 .mu.
thickness a layer was applied at 25.degree. C in a proportion of 1
g/sq.m from the following coating composition:
copolymer of vinylidene chloride, n-butyl- maleimide, and itaconic
acid (90:8:2) 8 g methylene chloride 80 ccs dichloroethane 20
ccs
To this layer a second layer was applied at 35.degree. C in a ratio
of 0.4 to 0.6 g/sq.m from the following composition:
20 % latex of copolymer of buta- diene and n-butyl acrylate (70:30)
6 g gelatin 0.80 g water 60 ccs methanol 40 ccs
This layer was coated successively with a known antistatic gelatin
layer and a light-sensitive gelatin silver halide emulsion layer as
commonly used in X-ray material. The adherence of the layers was
excellent.
EXAMPLE 12
To one side of a non-stretched polyethylene terephthalate film of
about 1 mm thickness a layer was applied at 25.degree. C in a
proportion of about 5 g/sq.m from a latex of a copolymer of vinyl
chloride, n-butyl acrylate, and itaconic acid (66:30:4).
This subbed film was simultaneously stretched longitudinally and
transversally to about 10 times its original size. Another layer
was applied at 40.degree. C to the vinylidene chloride layer in a
proportion of 0.4 to 0.6 g/sq.m from the following coating
composition:
20 % latex of copolymer of butadiene and ethyl hexyl acrylate
(60:40) 6 g gelatin 0.80 g water 60 ccs methanol 40 ccs
The dried material was then coated with a gelatin silver halide
emulsion layer as commonly used for graphic purposes.
The graphic material formed possessed an excellent adherence of the
layer in dry as well as in wet state.
EXAMPLE 13
A first subbing layer as described in Example 4 and a second
subbing layer as described in Example 3 were applied successively
to a biaxially stretched polyethylene terephthalate support of 100
.mu. thickness. The resulting material was then coated with a
light-sensitive layer prepared as follows:
120 g of zinc oxide was dispersed whilst stirring thoroughly in 700
ml of demineralised water, to which 2 g of sodium hexametaphosphate
had been added. A solution of 80 g of gelatin in 820 g of
demineralised water, 10 g of a 12.5 percent solution of saponine in
demineralised water, and 10 g of a 20 percent solution of
formaldehyde in demineralised water were added at 40.degree.C. The
mixture was then coated in a ratio of approximately 2 g of zinc
oxide per sq.m.
The dried light-sensitive material was exposed image-wise through a
transparent original and dipped in the following baths:
5 seconds in a 5 percent solution of silver nitrate in
demineralised water;
5 seconds in a 0.6 percent solution of p-monomethylaminophenol
sulphate in demineralised water;
30 seconds in an acid fixing bath containing 200 g of sodium
thiosulphate 5 aq. and 25 g of potassium metabisulphite per
litre.
Subsequently the material was rinsed for 5 minutes in running water
and then dried. A black negative image of the original was
obtained.
EXAMPLE 14
A biaxially oriented polyethylene terephthalate support having a
thickness of 100 .mu. was coated with a subbing layer consisting of
a solution in dichloroethane of a copolymer of vinylidene chloride,
N-tert.-butylacrylamide, n-butyl acrylate, and vinyl pyrrolidone
prepared as described in Example 1, in such a way that the
resulting dried layer had a thickness of 1 .mu..
30 g of titanium dioxide having a particle size of 15 to 40 .mu.
and a specific surface of approximately 50 sq.m/g were stirred for
2 min. with 150 ccs of demineralized water and 0.5 g of sodium
hexametaphosphate by means of an Ultra-Turrax stirrer, so that an
homogeneous dispersion was produced. To the resulting mixture a
solution at 30.degree. C of 12.5 g of gelatin in 412.5 ccs of
demineralized water and a 20 percent by weight latex of a copolymer
of butadiene and methyl methacrylate prepared as described in
Example 1 were added successively while stirring. Finally, 250 ccs
of demineralized water at 30.degree. C were added.
The resulting pigment dispersion was applied to the polyester film
subbed with vinylidene chloride copolymer in such a proportion that
1.59 of titanium dioxide were present per sq.m of the layer.
The dried material was then exposed image-wise through a
transparent original and dipped successively in the following
baths:
1. 30 sec. in a 10 percent by weight solution of silver nitrate in
demineralized water:
2. 30 sec. in a 3 percent by weight solution of
p-monomethylaminophenol sulphate in demineralized water;
3. 60 sec. in an acid fixing bath containing 200 g of sodium
thiosulphate 5 aq. and 25 g of potassium metabisulphite per
litre.
A sharp black negative silver image of the exposed original was
obtained upon rinsing and drying.
EXAMPLE 15
One side of a biaxially oriented polyethylene terephthalate film
having a thickness of 180 .mu. was coated with the following
composition at 25.degree.-30.degree. C in a ratio of 1.5 to 1.75
g/sq.m:
copolymer of vinylidene chloride, N-tert.-butylacrylamide, n-butyl
acrylate, and N-vinyl pyrrolidone prepared as described in example
1 5.5 g methylene chloride 65 ccs dichloroethane 35 ccs
The resulting layer was coated with a mixture of 95 parts by weight
of water and 5 parts by weight of ethylenechlorhydrin, which
mixture comprises 13.5 percent by weight of titanium dioxide, 1.6
percent by weight of gelatin, and 5 percent by weight of a latex of
the copolymer of butadine and methylmethacrylate (50:50 percent by
weight) prepared as described in Example 1. Upon drying the layer
formed had a thickness of 4-5 .mu.. The coating composition was
prepared as follows: 2,025 g of titanium dioxide was dispersed in
7,500 ccs of water with 37 ccs of hexametaphosphate as dispersing
agent. The dispersion was stirred fastly for 10 min. at
5.degree.-15.degree. C and then heated to 35.degree.C. A 10 percent
by weight aqueous solution of gelatin was added thereto while
stirring rapidly. The following composition was then added while
stirring slowly to avoid scumming:
10 % aqueous solution of gelatin 2600 ccs water 300 ccs 20 % by
weight latex of the copolymer of butadiene and methyl methacrylate
prepared as described in example 1 3750 ccs 10 % by weight aqueous
solution of the sodium salt of oleylmethyltauride 225 ccs
ethylenechlorhydrin 750 ccs
Before coating the dispersion having a viscosity at 35.degree. C of
8 cP was filtered.
The butadiene copolymer layer was then covered with a gelatin
silver halide emulsion layer as known in the graphic art. The thus
formed photographic material can be used whenever a dimensionally
stable support is needed and whenever the favourable light
reflection characteristics of the titanium dioxide layer are
needed.
In certain applications the titanium dioxide can be replaced by
other pigments, e.g. silicium dioxide.
EXAMPLE 16
In the same way as in Example 15, a biaxially oriented polyester
film is coated with a layer of vinylidene chloride copolymer. The
resulting layer was coated with a composition comprising 3 percent
by weight of carbon black, 1 percent by weight of gelatin, and 3
percent by weight of the copolymer of butadiene and methyl
methacrylate prepared as described in Example 1.
This composition was prepared as follows:
187.5 ccs of a 16 percent by weight aqueous dispersion of carbon
black comprising 2 percent by weight of poly-N-vinyl pyrrolidone
was diluted with 300 ccs of water. 5 ccs of a 40 percent by weight
latex of the copolymer of ethyl acrylate and N-vinyl pyrrolidone
(90:10 percent by weight) and 100 ccs of a 10 percent by weight
aqueous solution of gelatin were added thereto at 35.degree.C. The
mixture was stirred rapidly for 5 min. A mixture at 35.degree. C of
150 ccs of a 20 percent by weight latex of the copolymer of
butadiene and methyl methacrylate prepared as described in example
1, 15 ccs of a 10 percent by weight aqueous solution of the sodium
salt of oleylmethyltauride, 5 ml of a 40 percent by weight latex of
the copolymer of ethyl acrylate and n-vinyl pyrrolidone (90:10
percent by weight), and 187.5 ml of water were added thereto while
stirring slowly.
Subsequently 50 ml of methanol were added. The mixture was then
filtered while warm.
The vinylidene chloride copolymer layer was coated with this
composition so that upon drying a layer having a thickness of 4-5
.mu. was formed.
The latter layer was then coated successively with a gelatin
subbing layer and a high-sensitive gelatin silver halide emulsion
layer having a soft gradation.
The black-pigmented photographic material could be used for
producing images according to a silver complex diffusion transfer
process, wherein the sandwich formed by the light-sensitive and the
image-receiving layer can be removed from the camera or the
cassette during development of the negative image and during the
positive image formation by diffusion transfer.
* * * * *