JPH0571084B2 - - Google Patents

Description

[Detailed description of the invention]

A. Industrial Application Field The present invention relates to a silver halide photographic material provided with a back coat layer. B. Prior Art and its Problems Generally, silver halide photographic materials are composed of a support and a silver halide photographic constituent layer provided on the support. Such silver halide photographic constituent layers include a silver halide photographic emulsion layer, a protective layer, a subbing layer, an intermediate layer or color mixing prevention layer, an antihalation layer or filter layer, an ultraviolet absorbing layer, etc., and combinations thereof. It is what was done. For example, a single silver halide photographic material is
A silver halide emulsion layer and its protective layer are provided on a support. In addition, a multilayer silver halide color photographic material has a multilayer arrangement in which a blue-sensitive emulsion layer and an intermediate layer, a green-sensitive emulsion layer and an ultraviolet absorbing layer, a red-sensitive emulsion layer and a protective layer, etc. are sequentially provided on a support. Each color-sensitive emulsion layer contains yellow, magenta, and cyan color forming couplers. By the way, supports for silver halide photographic materials have conventionally been made of films such as polyethylene terephthalate film, cellulose triacetate film, polystyrene film, polycarbonate film, paper as a substrate, and resins capable of forming films on both sides, often polyolefins. Hydrophobic supports such as resin-coated papers coated with resins are well known. In particular, polyolefin resin-coated paper is increasingly being used as a support for photographic printing paper in place of the conventionally used baryta paper. The reason for this is that the polyolefin resin-coated paper used as a photographic support is hydrophobic.
This is because, compared to baryta paper, processing liquid is less likely to penetrate into the base paper layer during development and fixing of photographic paper, and therefore processing times such as washing and drying are shortened. However, these photographic hydrophobic supports have several drawbacks. A well-known drawback is that silver halide photographic materials with these hydrophobic supports tend to become statically charged and attract dirt, dust, etc. during their handling.
In addition to causing various spots such as water repellency, desensitization, and fogging, the accumulated static electricity is discharged, resulting in photographic properties called static marks in the silver halide photographic emulsion layer. Moreover, it may cause extremely unpleasant partial fogging. For this reason, it is known that an antistatic coating layer called an antistatic back coat layer is provided on the back side of a silver halide photographic material having a hydrophobic support, that is, on the surface of the support that is not coated with the silver halide photographic constituent layer. It is being For example, in order to provide antistatic performance,
The use of colloidal silica described in Japanese Patent Publication No. 30298, colloidal alumina described in Japanese Patent Publication No. 52-18020, and compounds having various carboxyl groups described in Japanese Patent Publication No. 58-9408 is known. . In addition, ethylene maleic anhydride copolymer described in Japanese Patent Publication No. 57-12980,
56859, a water-soluble polymer compound obtained by copolymerizing an ethylenically unsaturated copolymerizable monomer having 4 or more carbon atoms with maleic anhydride, or a salt thereof, Japanese Patent Publication No. 57-53940 It is also known to use organic polymer antistatic agents such as the water-soluble film-forming polymeric anionic polymer electrolytes described in No. However, when using silver halide photographic materials consisting of a hydrophobic support provided with these back coat layers and silver halide photographic constituent layers,
It had one or more serious shortcomings. For example, when used in high-sensitivity silver halide photographic materials, it may not be possible to sufficiently prevent static marks, or the antistatic performance may deteriorate after processing, causing prints to stick to each other, making handling inconvenient. Some of the components may detach, resulting in undesirable sludge build-up, or the back coat layer may be fragile or have weak adhesion to the hydrophobic resin, causing the interior of the printer to be damaged during exposure of silver halide photographic materials. There were cases in which the coating equipment was contaminated with powder, and the coating equipment was contaminated at the stage of coating the silver halide photographic constituent layers. C. OBJECTS OF THE INVENTION It is therefore a first object of the present invention to provide an improved silver halide photographic material having a hydrophobic support provided with a backcoat layer. That is, it is sufficiently antistatic and therefore prevents the formation of static marks, prevents prints from sticking to each other after processing, and does not cause contamination of the processing bath, printer, etc. It is an object of the present invention to provide a silver halide photographic material having a hydrophobic support provided with a backcoat layer. A second object of the present invention is to provide a silver halide photographic material provided with a back coat layer, which has excellent water resistance, especially resistance to developing solutions of the silver halide photographic material, and is therefore suitable for use in processing baths. An object of the present invention is to provide an excellent silver halide photographic material free from detachment of back coat components. Other objects, features, advantages, etc. of the present invention will be understood from the following description. D. Structure of the Invention As a result of intensive studies, the present inventors have found that the object of the present invention is to have a silver halide photographic constituent layer on one side of a hydrophobic support, and an aqueous binder with an average particle size on the opposite side. Colloidal silica with a diameter of 2 to 7 nm, and its surface contains 0.3 to 3.0% by weight of SiO ₂ in terms of Al ₂ O ₃
We have discovered that this can be achieved by a photographic material provided with a back coat layer containing a compound having two or more epoxy groups or ethyleneimino groups in aluminum-modified colloidal silica molecules, which led to the present invention. be. The aqueous binder used in carrying out the present invention is not particularly limited, but it can be cured or Particularly preferred are those that can be crosslinked. From the viewpoint of performance and economic efficiency of the back coat layer, water-based binders that are advantageously used in carrying out the present invention include:
Copolymers of ethylenically unsaturated copolymerizable monomers having 4 or more carbon atoms and maleic anhydride, hydrolysates or salts thereof, reaction products of these with polyvinyl alcohol, synthetic polymer latexes, carboxy-modified Examples include polyethylene, gelatin and modified products thereof, starch and modified products thereof, gums and modified products thereof, and combinations thereof. Preferred copolymers of ethylenically unsaturated copolymerizable monomers having 4 or more carbon atoms and maleic anhydride, hydrolysates thereof, or salts thereof include α-olefins having 4 or more carbon atoms, alkyl vinyl ethers, and styrene. Examples include a copolymer of an ethylenically unsaturated copolymerizable monomer and maleic anhydride, or a reaction product obtained by hydrolyzing the copolymer with an alkali such as sodium hydroxide or potassium hydroxide. . The molecular weight of the copolymer of an ethylenically unsaturated copolymerizable monomer having 4 or more carbon atoms and maleic anhydride is 2000.
~150000 is preferred. Specific examples include, for example, the pH of a solution obtained by hydrolyzing isobutylene, 1-pentene, butyl vinyl ether, or a copolymer of styrene and maleic anhydride with an alkali such as sodium hydroxide or potassium hydroxide. Examples include reaction products with a value of 5.0 to 9.5. In addition, reaction products of polyvinyl alcohol and water-soluble polymer compounds or salts thereof obtained by copolymerizing these ethylenically unsaturated copolymerizable monomers having 4 or more carbon atoms with maleic anhydride are also included. Included as preferred synthetic binders of the invention. For example, the reaction product of a water-soluble polymer compound or its salt obtained by copolymerization of isobutylene or styrene with maleic anhydride and polyvinyl alcohol is prepared by using the product with the highest possible purity. The degree of polymerization of polyvinyl alcohol is 500 to 1000, and the reaction conditions need to be adjusted depending on the blending ratio of both, molecular weight, pH of the liquid, and temperature.
Heating at ~98°C for 4 to 6 hours is suitable. The blending ratio (weight) of the copolymer of an ethylenically unsaturated copolymerizable monomer having 4 or more carbon atoms and maleic anhydride and polyvinyl alcohol is preferably 1:1 or less, and the higher the blending ratio of polyvinyl alcohol, the more the back coat is used. The antistatic properties of the layer deteriorate. Preferred synthetic polymer latexes are aqueous dispersions of water-soluble polymers with an average particle size of 10 to 200 mμ, such as acrylic latexes, vinyl acetate latexes, styrene-butadiene latexes, and acrylonitrile-butadiene latexes. Acrylic latexes include polyesters that are homopolymers of acrylic esters such as methyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate, and methacrylic esters such as methyl methacrylate and butyl methacrylate, or copolymer emulsions thereof. Copolymer emulsion of acrylic latex and ethylenically unsaturated copolymerizable monomer that can be copolymerized with acrylic acid ester or methacrylic acid ester, such as methyl methacrylate/butadiene latex, methyl methacrylate/styrene/butadiene latex, etc. Furthermore, those carboxy-modified latexes,
For example, carboxy-modified polyacrylic latex can be mentioned. Vinyl acetate latexes include polyvinyl acetate latex, vinyl acetate/acrylic acid ester copolymer latex, vinyl acetate/ethylene copolymer latex, and carboxy-modified latexes thereof; styrene/butadiene latexes include styrene/butadiene copolymer latex, etc. Examples include polymer latex, styrene/butadiene/acrylic ester and/or methacrylic ester copolymer latex, carboxy-modified styrene/butadiene latex, and the like. In addition to these examples, there may also be mentioned copolymer latexes containing monomer units having sulfonic acid. Preferred examples of carboxy-modified polyethylene include trade names such as Zaixen (manufactured by Seitetsu Kagaku Kogyo Co., Ltd.); In the polyethylene resin, some of the ethylene residues may be replaced with olefin residues having 10 or less carbon atoms. Carboxy-modified polyethylene may be dissolved or dispersed in water in the form of a salt with an alkali metal, alkaline earth metal, ammonia, amine, etc. The content of the aqueous binder used in the implementation of the present invention is not particularly limited, but from the balance of various performances of the back coat layer, it is 3 mg/m ² to 150 mg/m 2
A range of 7 mg/ ^{m 2 to} 60 mg/m ² is particularly preferred. The average particle size used in the practice of the present invention is 2~
7nm colloidal silica and its surface is Al ₂ O ₃
An example of colloidal silica modified with aluminum in an amount of 0.3 to 3.0% by weight relative to SiO ₂ is Snow Latex-SS (manufactured by Nissan Chemical Co., Ltd.). There is no particular limit to the amount of colloidal silica to be applied, which is colloidal silica with an average particle size of ₂ to ₇ nm and whose surface has been modified with aluminum to 0.3 to 3.0% by weight of SiO ₂ in terms of Al 2 O 3, but it is preferable. is 0.01
-2.0g/ ^m2 , particularly preferably 0.05-0.5g/ ^m2 . Specific examples of compounds having two or more ethyleneimino groups or epoxy groups in the molecule used in carrying out the present invention are shown below. Further, it is advantageous to dissolve these compounds in a suitable solvent such as water, methanol, ethanol, N,N-dimethylformamide, acetone, ethyl acetate, etc., and then incorporate them into the back coat layer.

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The content of these compounds is usefully in the range of 2.0% to 100% by weight, particularly preferably in the range of 7.5% to 30% by weight, based on the aqueous binder described in detail above. range. Further, as an advantageous embodiment, JP-A-59-
214849, the polymer latex described therein can be used in addition to the aqueous binder for the purpose of improving type printability. In addition, for the purpose of improving tape adhesion as stated in Japanese Patent Application No. 156959 (filed on July 27, 1982), salts or chelates of polyvalent metals with the same symbol are used.
The self-emulsifying emulsion described in No. 85204 (filed on April 20, 1960) can be used. Various types of hydrophobic supports can be used in the practice of the present invention. For example, synthetic papers such as polypropylene and polystyrene, films such as cellulose acetate, cellulose nitrate, polyethylene terephthalate, polyvinyl acetate, polystyrene, polyamide, and polycarbonate, as well as films made of paper as a substrate and polyolefin, polystyrene, polyvinyl chloride, etc. Examples include resin-coated paper coated with a resin capable of forming a film, often a polyolefin resin. In particular, as a support for photographic paper, especially roll photographic paper, which requires good tape adhesion and antistatic properties, polyolefin resin-coated paper is advantageous in that the effects of the present invention are more prominently exhibited. used for. In addition, in the resin layer of these thermoplastic resin films or resin-coated papers, white pigments such as titanium oxide, zinc oxide, talc, calcium carbonate, etc.
Fatty acid amides such as stearic acid amide and arachidic acid amide, dispersants such as fatty acid metal salts such as zinc stearate, magnesium stearate, and calcium palmitate, pigments and dyes such as ultramarine and cobalt violet, antioxidants, and fluorescence. It is preferable to contain a suitable combination of various additives such as brighteners and ultraviolet absorbers. The polyolefin resin-coated paper which is advantageously used in the practice of the present invention is manufactured by extrusion coating a molten polyolefin resin onto a running base paper through a slit die in the form of a film. At that time, it is desirable to activate the base paper surface by corona treatment, flame treatment, etc. prior to melt extrusion coating. The thickness of the coating resin layer is not particularly limited, but it is generally advantageous to have a thickness of about 5μ to 50μ. The side of the polyolefin resin-coated paper on which the silver halide photographic constituent layer is provided has a glossy surface, matte surface, silky surface, etc. depending on the purpose, and the back surface is usually a matte surface. Polyolefin resins for coating polyolefin resin-coated paper that are advantageously used in carrying out the present invention include low-density polyethylene, high-density polyethylene,
Examples include homopolymers of olefins such as polypropylene, polybutene, and polypentene, copolymers of two or more olefins such as ethylene-propylene copolymers, and mixtures thereof. ;hereinafter simply referred to as MI) can be used alone or in combination. As base paper for polyolefin resin coated paper, ordinary natural pulp paper,
Although either synthetic fiber paper or so-called synthetic paper made of synthetic resin film may be used, natural pulp paper whose main component is wood pulp such as softwood pulp, hardwood pulp, or softwood hardwood mixed pulp is advantageously used. There are no particular restrictions on the thickness of the base paper, but paper with good surface smoothness is preferred, and its basis weight is preferably 50 g/m ² to 250 g/m ² . In addition, the base paper mainly composed of natural pulp can contain various polymer compounds and additives, such as starch derivatives, polyacrylamide, polyvinyl alcohol derivatives, dry paper strength enhancers such as gelatin, Fatty acid salts, rosin derivatives, sizing agents such as dialkyl ketene dimer emulsions, wet paper strength agents such as melamine resins, urea resins, epoxidized polyamide resins, stabilizers, pigments, dyes, fluorescent brighteners, latex, inorganic An appropriate combination of electrolytes, PH adjusters, etc. can be included. The back coat layer according to the present invention can contain various polymer compounds and additives. Water-soluble polymers include starch derivatives such as oxidized starch and phosphated starch, gelatin thickeners such as cellulose sulfate, polyacrylamide, poly-N-vinylpyrrolidone, and sodium alginate; surfactants such as alkylbenzene; Anionic surfactants such as sulfonates and sulfosuccinates, nonionic surfactants such as saponins and alkylene oxide compounds,
Amphoteric surfactants such as amino acids, aminosulfonic acids, amino alcohol esters, etc., JP-A-Sho
Fluorine-based surfactants as exemplified in No. 50-99529, etc.
As a fluorescent whitening agent, Japanese Patent Publication No. 45-24068, Japanese Patent Publication No.
Compounds described or exemplified in No. 54-94318 and the like can be contained. Moreover, various matting agents can be contained. In carrying out the present invention, the apparatus for applying the back coat coating liquid onto the surface of the hydrophobic support opposite to the surface on which the silver halide photographic constituent layers are provided include an air knife coater, a roll coater, a bar coater, a blade coater, and a slide coater. Examples include hopper coaters, gravure coaters, flexogravure coaters, and combinations thereof. Prior to coating, it is desirable to activate the surface of the hydrophobic support by corona treatment, flame treatment, or the like. Further, the coating may be carried out by so-called on-machine coating using an on-machine device on a laminator immediately after coating the base paper with the resin capable of forming a film.
So-called off-machine coating may be performed using a separate coating device. Various drying devices are used to dry the applied coating liquid, including hot air dryers such as straight tunnel dryers, arch dryers, air loop dryers, and sine curve air float dryers, and dryers that use infrared rays, heated dryers, microwaves, etc. can be given. The silver halide photographic emulsion layer according to the present invention includes various types. For example, black and white photographic emulsion layer, color photographic emulsion layer, photographic emulsion layer for printing,
Direct positive photographic emulsion layers, etc., but the present invention is particularly useful in the case of emulsion layers for roll photographic paper. In addition, such photographic emulsion layers contain binders such as gelatin and gelatin derivatives, chemical sensitizers such as hypo, noble metal sensitizers such as gold salts and platinum salts, hexahalogenoiridium () complexes, hexahalogenorhodium () High contrast agents such as complexes, nucleic acid decomposition products, crystal habit regulators for silver halide grains such as mercapto heterocyclic compounds described or exemplified in JP-A-50-147925 and JP-A-51-107129, JP-A-52 −
Color sensitizers, stabilizers, antifoggants, color photographic couplers, hardeners, dihydroxybenzene compounds, coating aids cited or illustrated in No. 65432 and No. 52-88340, and It can contain fogging agents, additives for direct positive photographic emulsions such as dyes for direct positive photographs, dye developers, and other additives. The silver halide photographic material according to the present invention can be used for exposure, development, etc. as described in "Photographic Light-sensitive Materials and Handling Methods" (Kyoritsu Shuppan, written by Goro Miyamoto, Photographic Technology Course 2), depending on the photographic material. stop, fix, bleach,
Processes such as stabilization are carried out, especially after color development.
Multi-layer silver halide color photographic materials subjected to bath bleach-fixing can be prepared using any color developing solution with any main ingredient, such as CD-, CD- (the above two compounds are trade names of Kodatsu Co.), or droxychrome (trade name of May and Baker Co.). But it can be processed. Benzyl alcohol, thallium salt, phenidone, etc. may be added to the developer solution containing such a main agent. Also,
Useful one-bath bleach-fix solutions include metal salts of aminopolycarboxylic acids (e.g., ferric complex salts such as ethylenediaminetetraacetic acid, propylenediaminetetraacetic acid, etc.)
It is a solution, and the fixing agent is sodium thiosulfate,
Ammonium thiosulfate and the like are useful. Such a one-bath bleach-fix solution may contain various additives. For example, desilvering accelerators (e.g.
mercaptocarboxylic acids as described in U.S. Pat. No. 3,512,979, mercapto heterocyclic compounds as described in Belgian Patent No. 682,426), antifouling agents, PH regulators or PH buffering agents, hardening agents (for example, magnesium sulfate, aluminum sulfate). , potash alum, etc.),
Various compounds such as surfactants can be contained in combination. Also, although such single bath bleach-fix solutions can be used at various PHs, the useful PH range is
PH6.0-8.0. E Example Next, in order to explain the present invention more specifically,
An example will be described. Example 1 Paper with a basis weight of 160 g/m ² was run at 80 m/min, and after corona discharge treatment on the back side in the first zone, low density polyethylene (density 0.918, MI =
5) 50 parts, high density polyethylene (density 0.965, MI
=7) A resin composition consisting of 50 parts is melt-extruded and coated to a resin thickness of 30 μm to form a resin layer with a matte surface.
After corona discharge treatment on the cover surface in the second zone, low density polyethylene (density 0.918,
Resin composition consisting of 30 parts of masterbatch (MI=8.5) mixed with 30% by weight titanium oxide, 45 parts of low-density polyethylene (density 0.918, MI=5.0), and 25 parts of high-density polyethylene (density 0.965, MI=7.0). A resin layer with a glossy surface is formed by melt extrusion coating the object with a resin thickness of 30 μm. In the third zone, after corona discharge treatment is applied to the back resin surface, a rotating 140-mesh gravure roll is immersed in the coating liquid listed in Table 1, the excess coating liquid is scraped off with a blade, and the coating liquid is kept constant. A photographic support with antistatic properties was produced by transferring the mixture onto a surface and drying it. The coating amount of the aqueous coating liquid was 3 g/m ² (moisture).

【table】

[Evaluation of antistatic performance of back coat layer]

The surface resistivity of the sample was measured at 20° C. and 35% RH for the sample before color development and the sample after color development using a roll processor using the following processing method. Color development (30℃, 3 minutes 30 seconds) → Bleach fixing (30
℃, 1 minute 30 seconds) → Washing with water (30℃, 3 minutes) → Drying (45
℃, 1 minute) [Evaluation of film strength of back coat layer] After immersing in color developer for 3 minutes at 20℃, the sphere diameter was 1 mm.
The ball point needle is set perpendicular to the film surface of the back coat layer, and the load of the ball point needle that causes damage to the back coat film (hereinafter referred to as film strength) is calculated when the sample surface is moved in parallel at a speed of 2 cm/sec. Measure. The results obtained are shown in Table 2.

[Table] From Table 2, the sample without aqueous binder (No.
7) Samples containing no compound having two or more epoxy groups or ethyleneimino groups in the molecule (No. 5,
6) shows that the film strength is weak. Furthermore, it can be seen that when colloidal silica not limited to the present invention is used as the colloidal silica, the surface resistivity is higher than that of the present invention. Example 2 The same procedure as in Example 1 was carried out except that the coating liquid shown in Table 3 was used, and the results shown in Table 4 were obtained.

【table】

[Table] From Table 4, even if the average particle diameters are quite close, when colloidal silica not limited to the present invention is used, the surface resistivity is more than twice that of the present invention. F Effects of the Invention As can be seen from Examples 1 and 2, the present invention is excellent in achieving antistatic performance and scratch resistance (film strength) in a well-balanced manner.

Claims (1)

[Scope of Claims] 1. A hydrophobic support having at least one silver halide photographic photosensitive layer on one side, and at least an aqueous binder with an average particle size of 2 to 2 on the opposite side.
7nm colloidal silica and its surface is Al ₂ O ₃
A photographic material provided with a back coat layer containing a compound having two or more epoxy groups or ethyleneimino groups in colloidal silica molecules modified with aluminum in an amount of 0.3 to 3.0% by weight based on SiO ₂ . 2 The coating amount of the colloidal silica is 0.01 to 2.0
Photographic material according to claim 1, which is g/m ² .