AU427198B2 - Process for producing photographic materials - Google Patents

Description

25, 634 fz, This invention relates to a process for producing photographic materials having a light-sensitive layer con- a- Lo J taining gelatin or a" image receiving layer which is used for a silver salt diffusion transfer process on a white opaque polystyrene support (the so-called synthetic paper). Ritherto as the support of the photographic paper, haryta paper iwhich is prepared by coating the paper produced from pulp with barium sulfate has been used. However, this support has drawbacks, for example, expansion and contraction caused by variation of temperature and especially contraction

after developing treatment are caused, drying after development requires a long period of time, and the support has poor

resistance in water. Such drawbacks are resolved by using films of bydrophobic high molecularlsubstances, for example, a bi- axially stretched polystyrene film as the support of the photographic printing paper. In this case, however, the support should be whitened opaquely. This procedure is carried out by a method which comprises dipping a polystyrene film in a solvent or a swelling agent of polystyrene such as tetrahydrofuran, ethyl acetate and acetic acid, and dipping then in a non- solvent of polystyrene such as methanol and ethanol to form

a coarse surface. This support is notably preferable as the support of photographic paper because of its excellent water resistance, drying rate, dimensional stability, rigidity, whiteness and

opacity. How.ever, though the polystyrene has above-mentioned excellent characteristics as the support of photographic

427.198

2 5 6 34/p1 printing paper, it is very difficult to cause a fila formed

from photographic emulsions containing hydrophilic gelatin

to adhere firmly to the surface of the support, because it is

hydrophobic and chemically inactive. As means of changing such hydrophobic surface into hydrophilic one, there are

treatments by means of corona discharge, electron ray

application and ozone oxidation etc. which are disclosed

already in vapanesekPatent Application NoSae '44 4&g.- 695 and Sho 45 4163.

The process by this invention which does not contain the abovementibned two steps, that is, they comprise whitening

opaquely a transparent polystyrene support at first and then

performing a hydrophilic treatment of the resulting surface,

is characterized by that photographic materials are prepared

by whitening opaquely the transparent polystyrene support

and preparing a hydrophilic surface at the same time, and

applying emulsion or suspension containing gelatin to the

resulting surface, by which adhesion between said support and

the coating film is improved.

Namely, the present invention relates to a process for preparing photographic materials which comprises contract-

ing a bi-axial stretched polystyrene support with a liquid

which comprises at least a solvent or swelling agent of

polystyrene and gelatin dispersed therein, then contacting

the support with a non-solvent of polystyrene to prepare a

white opaque polystyrene support having a hydrophilic surface,

and applying emulsion or suspension containing gelatin to said

polystyrene support.

In this invention, "Emulsion or suspension contain-

ing gelatin" applied to the polystyrene means an acueous

42 71,a

25, 634/71 emulsion or aqueous suspension of gelatin which is prepared by adding or without adding silver halide such as silver

chloride, silver bromide, silver chlorobromide and silver

iodobromide, a light-sensitive diazo compound, substance of

center of development of the image receiving material used

in the silver salt diffusion transfer process, and another

necessary substances. After application of the aqueous

gelatin solution, the silver halide emulsion may be applied.

In this case, the coating film made from the aqueous gelatin

solution is a subbing layer for application of emulsions.

As being above-mentioned, a fine porous layer is formed on the bi-axial stretched polystyrene support by

contracting said polystyrene support with a solvent or swell-

ing agent thereof and then contacting the support with a non-

solvent of -polystyrene which can be compatible with said sol-

vent or swelling agent, by which said support becomes very

white and opaque.

When being subjected to permeation of the above-

mentioned solvent or swelling agent into the polystyrene sup-

port, if gelatin particles are dispersed in the solvent or swelling agent, the gelatin particles precipitate simultaneously

with formation of a fine porous layer, by which said poly-

styrene support becomes white and opaque and the surface

thereof becomes hydrophilic at the same time. Thus the

adhesive strength between the resulting white opaque and

hydrophilic polystyrene support and photographic emulsion

layer containing gelatin or/an image receiving coating layer in

the silver salt diffusion transfer process (hereinafter it is described as image receiving layer) exhibits a large value in

the dry state and the wet state at developement treatment.

427,198

The solvent and the sielling agent used in the above-mentioned treatment include, for example, methyl acetate. ethyl acetate, acetone, methylethylketone, methylene chloride,

ethylene chloride, tetrahydrofuran, cyclohexan, benzene, diox- ane, benzyl alcohol, trichlene and mixtures thereof. The non-solvent includes methanol and ethanol etc. In this invention, water, non-solvents and dispersing agents may be added suitably at dispersing the aqueous gelatin solution in said solvent or swelling agent. Further, though the amount of gelatin dispersed depends upon species of solvents, 0.1

by weight or so is preferable.

The adhesive strength between thus resulting support and the photographic emulsion layer containing gelatin or the image receiving layer does not exhibit any deterioration after the lapse of long period of time.

M4ethods of testing the adhesive strength between the photographic emulsion layer or image receiving layer and the film support in examples of this invention are as follows.

1. Method testing adhesive strength in dry state:

A cellulose triacetate film of 0.14 mm thickness is subjected to adhering to a surface of the emulsion layer or image receiving layer of the film support with using an epoxy adhesive. After letting stand at 230 C, 65% RH for a day, the resulting film is cut in a strip having 1cm of width and 15cm of length. The strip is then stripped off at 7.38cm/min of a drawing rate. The stripping strength is determined by strain

gauge. In the examples of this invention, good adhesion means the stripping strength is over 8g/mm, which endures in practice sufficiently as the adhesive strength between the emulsion

layer or image receiving layer and the support in photographic

427 198 materials. 2 5, 634 /71 2. Method of testing adhesive property in wet state: In steps of developing, fixing and rinsing, the same test of stripping is practiced as in the above-mentioned item 1. with using cyanoacrylate type adhesive. Good adhesion means the case of having more than 2g/mm of stripping strength. Example 1. After dipping a bi-axially stretched polystyrene supp- ort having 0.1 mm of thickness in a solution having the following composition at 20°C for 3 seconds, the support was dipped in methanol for another 30 seconds to prepare a hydrophilic white opaque polystyrene. Gelatin (10% aqueous solution) 8 cc

Salicylic acid (dispersing agent) 0.3g

Ethylene chloride

Methanol

Formalin (20% aqueous solution) 0.3cc

To the white opaque polystyrene support having hydrophilic surfaces above-meptioned, a gelatin-silver halide photographic emulsion having the following composition per 1 m2 of the film was applied. Silver chlorobromide (chlorine bromine

30 mols 70 mols) 3.5 g

Gelatin 13.0 g

Formalin (hardening agent) 0.1 g

Saponin 0.03 g

When the test of stripping was practiced to this

emulsion coated film, it exhibited more than 8g/mm of stripping

strength at the dry state and more than 2g/mm at the wet state.

Adhesion of the emulsion layer to the film support was good for

427,1 98

634/71 the photographic material. Further, this adhesive strength

did not deteriorate after the lapse of time.

On the contrary, when the transparent polystyrene

was treated with the above-mentioned solution in which gelatin

was not dispersed and when applying the above-mentioned

emulsion, adhesion at the dry state and the wet state was very

inferior, that is, the stripping strength was less than 2g/mm

at the dry state and nearly Og/mm at the wet state.

Example 2.

After dipping a hi-axial stretch polystyrene support

having 0.1mm of thickness in a solution having the following

composition at 20°C for 3 seconds the support was further

dipped in methanol for 30 seconds to prepare a white opaque

hydrophilic polystyrene support.

Gelatin (10% aqueous solution) 4 cc

Salicylic acid (dispersing agent) 0.3g

Benzene 50 cc

Acetone 50 cc

Formalin (20% aqueous solution) 0.3 cc

To the white opaque polystyrene having hydrophilic

surfaces above-mentioned, a coating solution of the image

receiving layer used for the silver salt diffusion transfer 2 process having the following composition per 1 m of the film

was applied.

Gelatin 3 g

Ag 2 S colloid 0.001g

Phenylmercaptotertrazole 0.01g

Saponin 0.02g

When the test of stripping the image receiving layer

from the support was practiced on this image receiving material, 427,1 98 it 2 5,6347 p exhibited satisfactory adhesive strength at either the dry state and the wet state for the image receiving material of the silver salt diffusion transfer process.

On the contrary, when the transparent polystyrene was treated with the above-mentioned solution in which gelatin was not dispersed and then applying the above-mentioned coating solution, adhesion was very inferior. t 3. After dipping a bi-axial stretched polystyrene supp- ort having 0.2mm of thickness in a solution having the following composition at 20°C for 3 seconds, the support was further dipped in methanol for 30 seconds to prepare a white opaque polystyrene support having hydrophilic surfaces. Gelatin (10% aqueous solution) '8 cc Salicylic acid /0.3 Methylene chloride 50 cc Methanol 50 cc Formalin (20% aqueous solution) 0.3cc To the opaquely whitened polystyrene support having hydrophilic surfaces, a gelatin-silver halide color photograph- ic emulsion having the following composition per 1 m2 of the film was applied.

Silver chlorobromide (chlorine bromine

30 mols 70 mols) Gelatin

Emulsified dispersion containing benzoyl-

anilide (yellow coupler) 14.Og Triethylene phosphamide acetone solution Polyvinylpyrrolidone 0.7g When the test of stripping the emulsion layer. from

4 271 98

634/71 the support was practiced on the above-mentioned color

photographic emulsion coating film, it exhibited satisfactory adhesive strength at either the dry state and the wet state for

the color photographic material.

On the contrary, when the transparent polystyrene.was

treated with the above-mentioned solution in which gelatin was not dispersed and then applying the above-mentioned color

emulsion, adhesion of the film was very inferior.

427. 198

Claims (1)

1. 634 pi The claims defining the invention are as follows:

   1. A process for producing photographic materials

   which is characterized by contacting a bi-axial stretched at least a polystyrene support with a liquid which contains dispersed solvent or swelling agent of polystyrene and gelatin

   therein, contacting the support with a non-solvent of polystyr- having a ene to prepare a white opaque polystyrene support

   hydrophilic surface, and applying an emulsion or suspension

   containing gelatin as the binder to said support.

   DATED this SEVENTEENTH day of FEBRUARY. 1971

   FUJI PHOTO FILM CO., LTD.

   Patent Attorneys for the Applicant SPRUSON FERGUSON

   427. 1 98