JPH0377977B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for subbing a film for photographic light-sensitive materials, and more specifically, when forming a photographic light-sensitive material consisting of a composite film in which a photographic light-sensitive emulsion layer is coated on a film, This invention relates to subbing processing of films for photographic materials using a styrene copolymerized acrylic emulsion and a compound containing two or more epoxide groups in order to improve adhesion, especially edge peeling in a processing solution. The fact that photographic emulsions applied directly to the surface of a plastic film base does not exhibit sufficient adhesion to the film base for its use in many of the common final photographic applications.
This is widely known in the field of photographic materials. As a result, it has become common practice to insert a subbing layer intermediate the film base and the photographic emulsion. Specifically, a photographic film usually consists of a support made of plastic film and a photographic emulsion coated on the support. However, photographic emulsions have considerable hydrophilicity, and it is difficult to achieve sufficient adhesion to hydrophobic plastic film supports. Therefore, prior to coating the hydrophobic support with a coating substance that has no affinity for the hydrophobic plastic film support, subbing processing has been carried out on the hydrophobic support. However, in order to use it as a photographic light-sensitive material, hydrophilic substances are transferred to a hydrophobic support under various handling conditions applied to photographic film in a wet state during processing and in a dry state before and after processing. Strong adhesion is required, and various adhesion methods have been tried in the past. For example, a vinylidene polymer, styrene-butadiene polymer, acrylic polymer, etc. containing a hydrophilic acid component is dissolved in an organic solvent such as ethylene chloride, dioxane, acetone, or methyl alcohol, and a support film and a photographic photosensitive layer are combined. In order to strengthen the adhesion, a method is used in which a subbing liquid prepared by adding an organic solvent such as chlorophenol or cresol, which is a solvent or swelling agent for the support film, is applied to the support film. However, in all of these processing methods using solvent-based subbing liquids, when the subbing liquid is applied and dried, organic solvent vapors that are harmful to the environment are emitted, which often causes problems in the work. Therefore, for example, a method is used in which a solvent-based subbing liquid that does not contain a solvent or a swelling agent is applied to the support film before stretching the support film, or after uniaxial stretching and before biaxial stretching. This method also poses manufacturing problems, such as stretching after drawing down, which makes it impossible to recover the peripheral portion of the film, resulting in a large amount of loss. The present invention aims to solve the above-mentioned problems, namely, by using an aqueous polymer dispersion as a subbing layer of the film, and also by adding a second sublayer using gelatin, which has been conventionally used to improve adhesive strength. The undercoat layer is omitted and only a single undercoat layer is used to maintain adhesion. The above purpose is to produce a self-supporting plastic film using a subbing liquid which is a mixture of an aqueous dispersion of an acrylic polymer containing styrene and/or a styrene derivative as a copolymer and a compound containing two or more epoxy groups in one molecule. coated on the surface, and a photographic emulsion layer on the surface of the subbing layer, an antihalation layer,
This can be achieved by a method of manufacturing a photographic film, which is characterized by directly coating a hydrophilic colloid layer such as a packing layer. For water-based submersible fluids containing epoxy compounds,
As described in JP-A No. 55-129344, a method of containing glycidyl methacrylate and/or glycidyl acrylate as a copolymerization component of a polymer has been used; Dry at 100℃ or higher for 3 minutes. The present invention provides water-soluble epoxy compounds such as glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, 3-methylpentanetriol triglycidyl ether, diglycerol triglycidyl ether, sorbitol triglycidyl ether, diglycidyl succinate. By using a compound such as ester or adipate glycidyl ester together with an acrylic copolymer containing styrene and/or a styrene derivative, a single layer can be formed.
This makes it possible to apply an undercoat layer that can achieve the desired purpose even under drying conditions of 80°C for 1 minute. Further, the ratio of styrene and/or styrene derivative to acrylate in the aqueous copolymer used in the present invention is such that the content of styrene and/or styrene derivative is 10 to 60.
The weight percentage can be arbitrarily selected, but 20 to 50 weight% is preferable. Also, acrylate can be selected arbitrarily. The aqueous copolymer dispersion of the present invention is produced by emulsion polymerization. In order to produce this, an emulsifying dispersant and a polymerization accelerator such as ammonium persulfate are added to a flask equipped with a reflux condenser and a heating device, and the resulting solution is maintained at about 60°C, while the copolymerization component monomer is polymerized dropwise in the heating device. An aqueous dispersion of copolymer is obtained. The amount of surfactant used in the reaction to be added is preferably 5% by weight or less, particularly around 1% by weight, based on the copolymerization component monomer. The particle size of the copolymer in the resulting dispersion varies depending on the amount of surfactant used and synthesis conditions such as reaction conditions and polymerization temperature, but it is usually preferably around 0.1 μm. Since the copolymer produced in this way is obtained as an aqueous dispersion, it may be used as a subbing liquid as it is, or if necessary, a diluting liquid, a surfactant, etc. may be added to form a subbing liquid. I can do it. The compositions of typical copolymers and comparative copolymers contained in the aqueous copolymer dispersion of the present invention are shown below, but the present invention is not limited thereto.

【table】

[Table] Any suitable plastic film can be selected as the self-supporting plastic film.
The polyesters used here include one or more dicarboxylic acids or their lower alkyl diesters, such as terephthalic acid, isophthalic acid, 2,5-, 2,6- and 2,7-naphthalenedicarboxylic acids, succinic acid. , sebacic acid, adipic acid, azelaic acid, diphenylcarboxylic acid and hexahydroterephthalic acid together with one or more glycols such as ethylene glycol, 1,3-propanediol, 1,
It can be prepared by condensation with 4-butanediol and neopentyl glycol. Biaxially oriented thermoset polyethylene terephthalate films are particularly useful in making photographic films according to the present invention. Such self-supporting plastic films are transparent and light-transmissive. The method of applying the subbing liquid may be any known application method. The hydrophilic treatment applied to the film surface may be any of various known methods, but corona discharge treatment and plasma treatment are preferred. Satisfactory adhesion can be achieved when the coating weight of the polymeric subbing layer is 10 to 500 mg/m ² . Advantageously, it is preferably comprised between 50 and 300 mg/m ² . EXAMPLES The present invention will be specifically explained below with reference to Examples, but the embodiments of the present invention are not limited thereby. The terms "dry adhesive strength" and "wet adhesive strength" used in the Examples have the following meanings. <Dry adhesive strength> Coat a photographic emulsion on a film base that has been subtracted, use a knife to make checkerboard-shaped scratches on the surface of the emulsion about 5 mm apart, then apply adhesive tape to this surface and quickly peel it off from the film. This is the adhesive strength evaluated by. In this method, if the peeling part is 0 to 5%, it will be grade A, if it is 5 to 30%, it will be grade B, and if 30 to 100% it will be grade C.
class. <Wet adhesion> At each stage of development, fixing, and washing, remove scratches on the emulsion surface of the film using a metal brush in the processing solution.
Apply it crosswise and rub the scratched area with your fingertips in a direction perpendicular to the line. Grade A is when the emulsion layer does not peel off beyond scratches, and B when the maximum peeling width is within 5 mm.
Class, if larger than this, it will be classified as C class. Example: The surface of a biaxially stretched polyethylene terephthalate film with a thickness of 175 μm was processed using a corona discharge treatment device at a film transport speed of 30 m/min and an electrode spacing.
1.5 mm, a power of 200 watts, and a current of 0.5 amperes. Next, exemplified compounds (1), (2), (3), (4), and (5) were diluted with water so that the solid content concentration was 10% by weight, and then 5% by weight of the solid content was diluted with water. Epoxy compounds (shown in Table 1) were added. The aqueous copolymer dispersion thus obtained (shown in Table 2) was applied as a subbing liquid to the surface of the corona discharge-treated polyethylene terephthalate film using an air knife coater and dried with hot air at 80 degrees for 1 minute. did. The solid content after drying obtained at this time was approximately 200 mg/m ² . A silver halide photographic emulsion containing silver bromide was coated on the subbing surface of the 15 types of polyethylene terephthalate films thus obtained to prepare samples 1 to 15. Next, separately from these samples, subbing liquids 16, 17, and 18 consisting of three types of acrylate aqueous dispersions and epoxy compound (3) were prepared and applied in the same manner as described above as comparison compounds. , 18. Then, a silver halide emulsion was coated in the same manner. Table 3 shows the results of the dry and wet adhesion tests for the above samples. As is clear from Table 3, the copolymer aqueous composition of the present invention and an epoxy compound containing two or more epoxy groups in the molecule (a mixture of (2) and (3) in Table 1) are coated as an undercoat layer. The polyethylene terephthalate support that was prepared and subjected to subbing treatment was subbed treated with a subbing liquid containing as a component an aqueous comparative copolymer composition or an epoxy compound containing only one epoxy group in the molecule. It can be seen that the adhesion is extremely superior to that of the polyethylene terephthalate support.

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Claims (1)

[Claims] 1. On a film support for photographic light-sensitive materials, (a) styrene and/or styrene derivative [formula] (R; H or alkyl) 10 to 60% by weight, acrylic ester CH ₂ =
A coating mixture of an aqueous dispersion of a copolymer consisting of 40 to 90% by weight of CH-CO ₂ R (R; alkyl) and 1 to 2% by weight of acrylic acid, and (b) a compound containing two or more epoxy groups. A method for undercoating a film for photographic materials, characterized by applying a liquid.