JP2899827B2 - Silver halide photographic material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a silver halide photographic material, and more particularly, to a silver halide photographic material having excellent dimensional stability.

[Background of the Invention]

Generally, gelatin is often used as a binder in silver halide photographic materials.

Gelatin has a high swelling property and gelling ability, is easy to crosslink with various hardeners, and adjusts the physical properties of the coating solution to a material that dislikes high temperature, such as photosensitive silver halide, to cover a large area. It is a binder having extremely excellent properties for uniform application over the entire surface.

In a silver halide photographic material, silver halide grains change into extremely hard metallic silver in a state where the gelatin layer has sufficiently absorbed water and swelled during development. Therefore, the emulsion layer does not return to its original state even after drying, and the size of the photosensitive material before and after processing may be different even if the photosensitive material is the same.

On the other hand, a technique for improving the physical properties of a light-sensitive material by incorporating a polymer latex in a silver halide emulsion layer and a backing layer is well known.

These techniques include, for example, Research Disclosure 19951, JP-B-39-4722, JP-B-39-17702, and JP-A-43-17.
-13482, U.S. Pat.Nos. 2,376,005, 2,763,625, and 27721
No. 66, No. 2852386, No. 2853457, No. 3397988. JP-A-59-38741, 61-296348
JP-A-61-284756, JP-A-61-285446 and the like disclose methods for incorporating micro oil droplets of paraffin or vinyl polymer. However, it is still not enough, and further improvement has been desired.

[Object of the invention]

In view of the above-described problems, an object of the present invention is to provide excellent dimensional stability, in particular, a small dimensional elongation before and after processing at low humidity and a small change in dimensional difference before and after processing even when the environmental humidity changes. An object of the present invention is to provide a silver halide photographic light-sensitive material.

[Configuration of the invention]

An object of the present invention is to provide a silver halide photographic material having at least one photosensitive silver halide emulsion layer on a support, wherein the emulsion layer contains 100 to 200% by weight of gelatin of polymer latex. This is achieved by a silver halide photographic light-sensitive material characterized by the following.

In a preferred embodiment of the present invention, the polymer latex has a Tg of 20 ° C. or less, the support is a polyester, and at least one surface of the polyester support contains at least 20% or more of polyvinylidene chloride. It is preferable to have an undercoat layer containing a polymer as a component.

Hereinafter, the present invention will be described more specifically. The inventor of the present invention has found that there is a specific boundary in the ratio between the amounts of gelatin and latex in the process of continuing to study the improvement of the physical properties of the light-sensitive material. It was also found that selection of latex Tg further amplified this effect.

Examples of the polymer latex contained in the photographic light-sensitive material of the present invention include, for example, U.S. Pat. Nos. 2,772,166 and 3,32
5,286, 3,411,911, 3,311,912, 3,525,620
No., Research Disclos
ure) No. 195 19551 (July 1980), as described in acrylic esters, methacrylic esters,
There are hydrates of vinyl polymers such as styrene.

As the polymer latex preferably used in the present invention, a homopolymer of methalkyl acrylate such as methyl methacrylate and ethyl methacrylate, a homopolymer of styrene, or a methalkyl acrylate or styrene and acrylic acid, N-methylol acrylamide, glycidol methacrylate or the like And a copolymer of alkyl acrylate such as methyl acrylate, ethyl acrylate and butyl acrylate or a copolymer of alkyl acrylate with acrylic acid, N-methylol acrylamide and the like (preferably a copolymer component such as acrylic acid is Up to 30% by weight), butadiene homopolymer or butadiene and styrene, butoxymethylacrylamide,
Copolymers with one or more acrylic acids, vinylidene chloride
Methyl acrylate-acrylic acid terpolymer is exemplified.

Specific examples of the latex that can be used in the present invention are shown below. It is particularly preferred that these latexes have a Tg of 20 ° C. or lower, but the Tg of a polymer latex composed of a copolymer of two or more components can be easily adjusted by changing the component ratio, and is shown herein. Specific examples of the latex represent latexes having an arbitrary composition ratio of the latex composed of the constituent components. Of course, the specific example of latex shown here is only one of the latexes that can be used.
It is an example, and it goes without saying that the constituent components (not only the composition ratio) of the latex used in the present invention are not limited to these specific examples.

The preferred range of the average particle size of the polymer latex used in the present invention is 0.005 to 1 μm, particularly 0.02 to 0.1 μm.

Gelatin amount of preferred emulsion layer is preferably 3 g / m ² or less, 2.5 g / m ² or less is particularly preferred.

The polymer latex used in the present invention may be contained on only one side of the support, or may be contained on both sides. When the polymer latex is contained on both sides of the support, the type and / or amount of the polymer latex contained on each side may be the same or different.

Further, the polymer latex is added to any layer other than the photosensitive hydrophilic colloid layer if it is contained in at least one silver halide emulsion layer with respect to the support. be able to.

General additives and known contrast agents and the method for producing silver halide grains according to the present invention, the sensitization method and the like,
There is no particular limitation. For example, Japanese Patent Application Laid-Open No. 63-230035,
No. 266640 can be referred to.

In the present invention, for the purpose of preventing static electricity, which is another physical property of the photosensitive material, the backing side of the support and / or
Alternatively, one or more antistatic layers can be provided on the emulsion layer side.

In this case, the surface resistivity on the side provided with the antistatic layer is 25
It is preferably 1.0 × 10 ¹¹ Ω or less at 50 ° C., particularly preferably 8 × 10 ¹¹ Ω or less.

The antistatic layer is preferably an antistatic layer containing a reaction product of a water-soluble conductive polymer, hydrophobic polymer particles and a curing agent.

As the water-soluble conductive polymer, a sulfonic acid group,
Examples include polymers having at least one conductive group selected from a sulfate group, a quaternary ammonium salt, a tertiary ammonium salt, and a carboxyl group polyethylene oxide group. Among these groups, a sulfonic acid group, a sulfate group, and a quaternary ammonium base are preferable. The conductive group requires 5% by weight or more per molecule of the water-soluble conductive polymer.

Also, carboxyl groups in the water-soluble conductive polymer,
Hydroxy group, amino group, epoxy group, aziridine group,
An active methylene group, a sulfinic acid group, an aldehyde group, a vinylsulfone group and the like are included, and among these, a carboxyl group, a hydroxy group, an amino group, an epoxy group, an aziridine group, and an aldehyde group are preferably included. These groups must be contained in an amount of 5% by weight or more per polymer molecule. The number average molecular weight of the water-soluble conductive polymer is 3000 to 100,000, preferably 3500 to 50
000.

Further, as the metal oxide, tin oxide, indium oxide, antimony oxide, zinc oxide, or a material obtained by doping these metal oxides with metal phosphorus or metal indium is preferably used. The average particle size of these metal oxides is preferably 1 μm to 0.01 μm.

Further, when the lower layer is an emulsion layer, the matting agent enters the emulsion layer by pressure because it is still in a soft state, so that the emulsion layer is partially destroyed to cause a coating failure. The winding tension also causes the same problem.

As the matting agent used in the present invention, any known matting agents can be used. Swiss patent for example
Inorganic particles such as silica described in 330,158, glass powder described in French Patent 1,296,995, alkaline earth metal or cadmium described in British Patent 1,173,181, carbonate such as zinc; starch described in U.S. Pat. No. 2,322,037 Starch derivatives described in Belgian Patent 625,451 or British Patent 981,198, polyvinyl alcohol described in JP-B-44-3643, polystyrene or polymethyl methacrylate described in Swiss Patent 330,158, US Patent 3,079,257
No. 3,022,169.
Organic particles such as the polycarbonate described in the above item.

These matting agents may be used alone or in combination. The shape of the matting agent is preferably spherical as a regular matting agent, but may be another shape such as a flat plate shape or a cubic shape. The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a sphere. In the present invention, the mat particle size refers to the diameter converted into a sphere.

In a preferred embodiment of the present invention, it is preferable that the outermost layer on the emulsion surface side contains 4-80 mg / m ² of at least one of a regular and / or irregular matting agent having a matting particle size of 4 μm or more. More preferably, at least one of a regular and / or irregular matting agent having a particle size of less than 4 μm is used in an amount of 4 mg / m ^{2 to} 80 mg / m ^2.
2 together.

In addition, the fact that the matting agent is contained in the outermost layer preferably means that at least one part of the matting agent is contained in the outermost layer, even if one part of the matting agent reaches a layer below the outermost layer. Good.

In order to fulfill the basic function of the matting agent, it is desirable that a part of the matting agent is exposed on the surface. The matting agent exposed on the surface may be a part of the added matting agent or may be all. The method of adding the matting agent may be a method of dispersing in a coating solution in advance and applying,
After applying the coating liquid, a method such as spraying a matting agent before drying is completed may be used. When a plurality of different matting agents are added, both methods may be used in combination. Manufacturing techniques for more effectively adding these matting agents to the light-sensitive material are described in Japanese Patent Application No. 1-228762.

The undercoat layer that can be used in the present invention is disclosed in
JP-A-49-3972, JP-A-49-11118 and JP-A-52-1, undercoating layers in an organic solvent system containing polyhydroxybenzenes.
No. 04913, No. 59-19941, No. 59-19940, No. 59-18945
No. 51-112326, No. 51-17617, No. 51-58469,
Nos. 51-114120, 51-121323, 51-123139,
51-114121, 52-139320, 52-65422, 52
-109923, 52-119919, 55-65949, 57-1
Examples include aqueous latex subbing layers described in Nos. 28332, 59-19941, etc., and more preferably Japanese Patent Application No. 1-14.
0872, 1-143914, 1-323607, 1-1813
No. 06, No. 1-18305, No. 1-189663, No. 1-19748.

In addition, the surface of the undercoat layer can be usually chemically or physically treated. Examples of the treatment include surface treatment such as chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment, and ozone oxidation treatment. .

The undercoat layer is distinguished from the coating layer according to the present invention, and there is no limitation on the coating time and conditions.

However, embodiments of the present invention show a more significant effect when coated on a polyester support provided with a vinylidene chloride based undercoat.

The vinylidene chloride copolymer in the present invention is 70 to 9
A copolymer containing 9.5% by weight, preferably 85 to 99% by weight, of vinylidene chloride; a copolymer comprising vinylidene chloride / acrylate / vinyl monomer having an alcohol in a side chain described in JP-A-51-135526. Polymer, U.S. Patent 2,852,37
A copolymer of vinylidene chloride / alkyl acrylate / acrylic acid described in No. 8, a copolymer of vinylidene chloride / acrylonitrile / itaconic acid of US Pat. No. 2,698,235, and a vinylidene chloride / alkyl acrylate / itaconic acid of US Pat. No. 3,788,856 And the like. The following are specific examples of the compound.

 All figures in parentheses indicate weight ratios.

Vinylidene chloride: methyl acrylate: hydroxyethyl acrylate (83: 12: 2) copolymer Vinylidene chloride: ethyl methacrylate: hydroxypropyl acrylate (82: 10: 8) copolymer Vinylidene chloride: hydroxydiethyl methacrylate (92: 8) ) Copolymer of vinylidene chloride: butyl acrylate: copolymer of acrylic acid (94: 4: 2) Vinyl chloride: butyl acrylate: copolymer of itaconic acid (75: 20: 5) Vinylidene chloride: methyl acrylate: itacone Copolymer of acid (90: 8: 2) Vinylidene chloride: methyl acrylate: methacrylic acid (93: 4: 3) Vinylidene chloride: itaconic acid monoethyl ester (9
5: 4) copolymer vinylidene chloride: acrylonitrile: acrylic acid (9
6: 3.5: 1.5) Copolymer of vinylidene chloride: methyl acrylate: copolymer of acrylic acid (90: 5: 5) Vinylidene chloride: ethyl acrylate: copolymer of acrylic acid (92: 5: 2) Vinylidene chloride : Methyl acrylate: 3-chloro-2
-Hydroxypropyl acrylate (84: 9: 7) copolymer Vinylidene chloride: methyl acrylate: N-ethanolacrylamide (85: 10: 5) copolymer The plastic film having an antistatic layer of the present invention is, for example, a photosensitive material. Can be applied to the support. As the photosensitive material, for example, silver halide color photosensitive material,
X-ray photosensitive materials, plate making photosensitive materials, and the like.

In the present invention, a solid-dispersed dye may be contained in any of the hydrophilic colloid layers in addition to the ordinary water-soluble dye. The layer may be the outermost layer on the emulsion surface side, and may be a layer below the emulsion layer and / or
Alternatively, it may be added to the backing surface side. Further, an appropriate amount may be added to the emulsion layer for adjusting irradiation. Of course, a plurality of layers may contain a plurality of types of solid disperse dyes.

The amount of the solid disperse dye added was 5 mg / m ² per type.
11 g / m ² , particularly preferably 10 mg / m ² 800800 mg / m ²
a m ^2.

Fine particles of the solid dispersion used, the dye is pulverized by a ball mill, or a disperser such as a sand mill, water,
Alternatively, it can be obtained by dispersing together with a hydrophilic colloid such as gelatin, a surfactant such as sodium dodecylbenzenesulfonate, sodium fluorooctylbenzenesulfonate, saponin, and nonylphenoxy polyethylene glycol.

The general formula of the dye used in the present invention is described in U.S. Pat.
Nos. 4,857,446 and the like, for example, those represented by general formulas [I] to [V] are preferably used.

The present invention can be applied to various photosensitive materials such as for printing, X-ray, general negative, general reversal, general positive, and direct positive, but printing requiring extremely high dimensional stability is required. When applied to photosensitive materials for use, particularly remarkable effects can be obtained.

The development temperature of the silver halide photographic light-sensitive material according to the present invention is
50 ° C. or lower is preferable, and particularly preferably around 25 ° C. to 40 ° C.,
Although the development processing time is generally completed within 2 minutes, a more preferable effect can be obtained particularly when rapid processing is performed for 5 to 60 seconds.

(Example I) Examples of the present invention will be specifically described below, but it goes without saying that the present invention is not limited to these examples.

(Synthesis of latex Lx) 0.125 kg of gelatin and ammonium persulfate in 40 l of water
Under a nitrogen atmosphere, a mixture of (a) 4.51 kg of n-butyl acrylate, 5.49 kg of (a) styrene, and 0.1 kg of (c) acrylic acid was added to a solution containing 0.05 kg while stirring at a liquid temperature of 80 ° C.
After adding over time, and then stirring for 1.5 hours, gelatin 1.25K
g and ammonium persulfate 0.005Kg and stirred for 1.5 hours,
After the reaction was completed, the remaining monomers were removed by steam distillation for 1 hour, and then cooled to room temperature, and the pH was adjusted to 6.0 with ammonia. The obtained latex liquid is 50.
Finished to 5kg.

As described above, a monodispersed latex having an average particle size of 0.25 μm and a Tg of about 0 ° C. was obtained.

(Preparation of emulsion) A solution obtained by adding a rhodium hexachloride complex to a silver sulfate solution and an aqueous solution of sodium chloride and potassium bromide at a concentration of 8 × 10 ⁻⁵ mol / Agmol was simultaneously added to a gelatin solution while controlling the flow rate. After desalting, a cubic, monodispersed, silver chlorobromide emulsion containing 0.13 μm in particle size and 1 mol% of silver bromide was obtained.

This emulsion was subjected to sulfur sensitization by a conventional method, and 6-methyl-4-hydroxy-1,3,3a, 7 tetrazaindene was added as a stabilizer, and the following additives were added to the emulsion coating solution E- 1 to
Then, an emulsion protective layer coating solution P-0, a backing layer coating solution B-0, and a backing protective layer coating solution BP-0 were prepared according to the following composition.

(Preparation of Emulsion Coating Solutions E-1 to 14) Compound (a) 1 mg / m ² NaOH (0.5N) Adjusted to pH 5.6 Compound (b) 40 mg / m ² Compound (c) 30 mg / m ² Savonin (20% ) 0.5 cc / m ² sodium dodecylbenzenesulfonate 20 mg / m ² 5-methylbenzotriazole 10 mg / m ² Compound (d) 2 mg / m ² Compound (e) 10 mg Compound (f) 6 mg / m ² Latex Lx Amount shown Styrene-maleic acid co-water-based polymer (thickener) 90mg / m ² (Emulsion protective layer coating solution P-0) Gelatin 0.5 g / m ² compound (g) (1%) 25 cc / m ² compound (h) 120 mg / m ² spherical monodisperse silica (8 μ) 20 mg / m ² 〃 (3 μm) 10 mg / m ² compound (i) 100 mg / m ² citric acid adjusted to pH 6.0 (backing layer coating solution B-0) Gelatin 1.0 g / m ² compound (j) 100 mg / m ² compound (h) 18 mg / m ² compound (l) 100 mg / m ² saponin (20%) 0.6cc / m ² latex (m) 300mg / m ² 5- nitroindazole 20 mg / m ² styrene - maleic acid copolymer aqueous polymer (thickener) 45 mg / m ² glyoxal 4 mg / m ² (backing protective layer coating solution BP-0) gelatin 0.5 g / m ² compound (g) (1%) 2cc / m 2 spherical polymethylmethacrylate (4 [mu]) 25 mg / m ² sodium chloride 70 mg / m ² glyoxal 22 mg / m ² Compound (n) 10 mg / m ² Each of the coating solutions adjusted as described above was subjected to corona discharge at 10 W / (m ² · min) on a 100 μm-thick polyethylene terephthalate base undercoated as shown in JP-A-59-19941. The following composition was applied using a roll-fit coating pan and an air knife. The drying was carried out for 30 ″ under parallel flow drying conditions of 90 ° C. and an overall heat transfer coefficient of 25 Kcal (m ² · hr · ° C.), followed by drying at 140 ° C. for 90 seconds. 1μ, surface resistivity of this layer is 23 ° C 55
% Was 1 × 10 ⁸ Ω.

Water-soluble polymer 70g / l 40g / l hydrophobic polymer particles Ammonium sulfate 0.5g / l Polyethylene oxide compound (average molecular weight 600) 6g / l Curing agent 12g / l First, the emulsion layer and the emulsion protective layer were coated simultaneously on the base from the side closer to the support in the order of emulsion layer and emulsion protective layer while adding a hardener solution by a slide hopper method while maintaining the temperature at 35 ° C. ° C), then apply a backing layer and a backing protective layer using a slide hopper while adding a hardening agent, and set a cold air (5 ° C).
did. At the time of passing through each set zone, the coating liquid showed sufficient setting properties. Subsequently, both surfaces were simultaneously dried in the drying zone under the following drying conditions. In addition, after coating both sides of the backing, it was conveyed in a state of non-contact with a roller and other parts until winding up.

 At this time, the coating speed was 100 m / min.

(Drying conditions) 30% after setting until the weight ratio of H ₂ O / gelatin reaches 800%
Dry at 800 ° C with a dry air at 80 ° C, dry at 800 ° C to 200% with a dry air at 35 ° C (30%), and apply the air as it is. Dry for 1 minute at 16 ° C air. At this time, the drying time is from the start of drying to H ₂
O / Gel ratio up to 800% is 50 seconds, from 800% to 200% is 35 seconds, 20
0% to the end of drying or 5 seconds.

The photosensitive material was wound at 23 ° C. and 40%, cut in the same environment, and placed in a barrier bag conditioned for 3 hours in the same environment.
(Humidity was controlled at 10 ° C for 8 hours and then at 23 ° C for 40% for 2 hours).

The coated silver amount of the light-sensitive material prepared as described above was 3.5 g / m ² .

The dimensional stability of the evaluation samples Nos. 1 to 14 formed as described above was evaluated as follows.

(Dimensional stability) Cut the sample into a size of 30cm x 60cm,
Approximately 56cm using -627FM (Dainippon Screen)
The two fine lines were subjected to image exposure and developed to obtain a document.

After the original, unexposed sample (same size as the original), printer and automatic processor were conditioned at 23 ° C and 20% for 2 hours,
The original was exposed in close contact (surface-to-surface) with an unexposed sample and processed by an automatic processor. After the developed sample was conditioned for 2 hours, the sample was overlaid on the original document, and the distance between the fine lines was measured using a loupe with a scale.

The measurement was performed with n = 6, and the average was taken. (Value (a)) The same experiment was performed at 23 ° C. and 60%, and the difference from the value of the dimensional difference before and after the treatment at 20% (indicating the dependency on the environmental humidity) was obtained. ((B) value) When the (a) value exceeds ± 20μ, the dimensional deviation is recognized, and when the (b) value exceeds 20μ, the dimensional difference before and after the processing is recognized, and the setting of some working conditions is changed. Is the required level.

(Standard processing conditions) Developing 28 ° C 30 seconds Fixing 28 ° C 20 seconds Water washing Room temperature 15 seconds Drying 40 ° C 35 seconds [Developer solution formulation] (Composition A) Pure water (ion-exchanged water) 150 ml Ethylenediaminetetraacid disodium salt 2 g Diethylene glycol 50 g Potassium sulfite (55% W / V aqueous solution) 100 ml Potassium carbonate 50 g Hydroquinone 15 g 5-Methylbenzotriazole 200 mg 1-Phenyl-5-mercaptotetrazole 30 mg Potassium hydroxide Amount to bring the pH of the working solution to 10.9 Potassium bromide 4.5 g ( Composition B) Pure water (ion-exchanged water) 3 ml Diethylene glycol 50 mg Disodium ethylenediaminetetraacid 25 mg Acidic acid (90% aqueous solution) 0.3 ml 5-Nitroindazole 110 mg 1-phenyl-3-pyrazolidone 500 mg Water 500 ml when using a developer The above composition A and composition B were dissolved in this order, and finished to 1 for use.

(Fixing solution formulation)

(Composition A) Ammonium thiosulfate (72.5% W / V aqueous solution) 230ml Sodium sulfite 9.5g Sodium oxyacid trihydrate 15.9g Boric acid 6.7g Sodium citrate dihydrate 2g Acid acid (90% W / V aqueous solution) 8.1 ml (Composition B) Pure water (ion-exchanged water) 17 ml Sulfuric acid (50% W / V aqueous solution) 5.8 g Aluminum sulfate (aqueous solution whose content in terms of Al ₂ O ₃ is 8.1% W / V) 26.5 g Water when using the fixing solution The above composition A and composition B were dissolved in 500 ml in this order, and finished to 1 for use. This fixer pH is about
4.3.

 The results are shown in Table 1.

Example 2 Latexes La-1 to La-4 were synthesized in the same manner except that the Tg was changed by changing the copolymerization ratio of n-butyl acrylate and styrene in the composition of the latex of the present invention synthesized in Example 1. . Latex Lb- was obtained in the same manner as in Example 1 except that ethyl acrylate was used instead of n-butyl acrylate, and methyl methacrylate was used instead of styrene, and that the Tg was changed by adjusting the composition ratio of the two. 1-4 were synthesized. Using these latexes, a sample was prepared in the configuration of Example 1, No. 9,
The dimensional stability was measured using Example 1, No. 6 as a comparison.

The dimensional difference before and after treatment at 23 ° C 20% below Tg 20 ° C
It can be seen that the Tg is further reduced by about 20 μ compared to the case where the Tg is higher than 20 ° C.

Example 3 Evaluation samples 23 to 31 were obtained in the same manner as in Example 1 except that the PET-based undercoating of the embodiment of the present invention in Example 1 was replaced by vinylidene chloride undercoating described in US Pat. No. 4,645,731.
Table 3 shows the results of the same evaluation as in Example 1 for these samples.

Example 4 Samples Nos. 32 to 40 were prepared in the same manner as in Example 3 except that the processing conditions were as described below, and the same experiment was performed. Table 4 shows the results.

(Rapid processing conditions) Developing 28 ° C for 8 seconds Fixing 28 ° C for 8 seconds Washing at room temperature for 6 seconds Drying at 40 ° C for 6 seconds It can be seen that rapid processing is more effective for dimensional stability.

(Effects of the Invention) As is clear from Example 1, according to the embodiment of the present invention, it is possible to provide a photosensitive material having extremely excellent dimensional stability and stability.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03C 1/04 G03C 1/93

Claims (3)

(57) [Claims] 1. A silver halide photographic material having at least one photosensitive silver halide emulsion layer on a support, wherein said emulsion layer contains 100 to 200% by weight of gelatin of a polymer latex. Characteristic silver halide photographic material. 2. The silver halide photographic material according to claim 1, wherein the polymer latex has a Tg of 20 ° C. or less. 3. The support according to claim 1, wherein the support is a polyester, and at least one surface of the polyester support has an undercoat layer containing, as a component, a copolymer containing at least 20% or more of polyvinylidene chloride. Item 3. A silver halide photographic material according to item 1 or 2.