JPH0476095B2 - - Google Patents

Description

[Detailed description of the invention]

A. Field of Industrial Application The present invention relates to photographic paper that can be used as postcards, and more specifically, photographic paper that can be used as postcards and has good writing aptitude with various writing instruments after being developed and dried. It is related to. 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 a color mixing prevention layer, an antihalation layer or a filter layer, an ultraviolet absorbing layer, etc., and combinations thereof. It is what was done. For example, a single silver halide photographic material has a silver halide emulsion layer and its protective layer on a support. Multilayer silver halide color photographic materials also include a blue-sensitive emulsion and an intermediate layer on a support.
A green-sensitive emulsion layer, an ultraviolet absorbing layer, a red-sensitive emulsion layer, a protective layer, etc. are sequentially provided in a multilayer arrangement, and each color-sensitive emulsion layer contains yellow, magenta, and cyan coloring couplers, respectively. 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 polyolefin resins. Hydrophobic supports such as resin-coated papers coated with 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, so the development of photographic printing paper is faster than that of baryta paper.
This is because the processing liquid is less likely to penetrate into the base paper layer during the fixing process, which has the advantage of shortening processing times such as washing and drying. On the other hand, in order to use photographic paper as a postcard, when writing, drawing, or stamping on the side opposite to the image after development, the ink must dry quickly and be protected against friction. It is necessary that the ink does not fall off or smudge even when applied. However, as mentioned above, the side of photographic paper opposite to the image is coated with a hydrophobic and soft polyolefin resin, so it is difficult to write on it with a pencil or pen, and it is also difficult to write on it with a stamp. Even if you press the ink, it takes a long time to dry because it is essentially non-absorbent, and even after drying, the ink can easily fall off due to friction, contact, etc., contaminating the surrounding area, or in extreme cases, the stamp may disappear completely. It disappears and its purpose cannot be achieved. In order to achieve such an objective, it is known in the art to provide a backcoat layer essentially consisting of a liquid-absorbing inorganic pigment and a binder on the side of the hydrophobic support opposite the image of the photographic paper. For example, in JP-A No. 58-184144, a preferred embodiment includes 15 to 50 parts by weight of an inorganic pigment with an oil absorption of 100 c.c./100 g or more, 85 to 50 parts by weight of gelatin, and 0.20 parts by weight of gelatin. A backcoat layer is disclosed that includes a specific hardener of gelatin from % to 3.0% by weight. However, in this method, when the amount of liquid-absorbing inorganic pigment used is small, the ink absorption rate is slow, and the back coat surface is constantly leaking ink, making handling inconvenient. In addition, if the liquid-absorbing inorganic pigment has a high liquid-absorbing ability and occupies a high proportion in the back coat layer, the leakage of ink from the back coat surface will be reduced, but the tendency of the ink to bleed will increase, and in severe cases, characters will be It has the disadvantage of being difficult to read. C. OBJECT OF THE INVENTION Therefore, an object of the present invention is to provide a photographic paper having a back coat layer that has a sufficient ink absorption speed and less ink bleeding. As a result of intensive research, the present inventors have found that by using two or more types of porous silica with different particle sizes, it is possible to achieve both the performance of quickly absorbing ink and the performance of preventing ink from bleeding. This discovery led to the present invention. D. Structure of the Invention That is, the object of the present invention is to have a silver halide photographic constituent layer on one side of a resin-coated paper-type photographic support in which both sides of a base paper are coated with resin, and a support on the opposite side. At least gelatin on the body surface, average particle size
This is achieved by a photographic paper characterized by being provided with a back coat layer containing porous silica of 0.8μ to 2.0μ and porous silica with an average particle size of 4.0μ to 10.0μ. In carrying out the present invention, the ratio of gelatin to porous silica to be used is preferably in the range of 2:1 to 1:2 by weight, and the coating amount of porous silica is 0.5.
The range is preferably from g/m ² to 5.0 g/m ² , particularly preferably from 0.7 g/m ² to 2.5 g/m ² . If the amount of porous silica is too small relative to the gelatin, sufficient ink absorption ability will not be obtained and the ink will dry slowly, while if it is too large, the ink will easily bleed. If the amount of porous silica applied is too small, sufficient ink absorption ability will not be obtained and the ink will dry slowly. On the other hand, if the amount is too large, the curl properties will deteriorate and productivity will also deteriorate. Gelatins used in the practice of this invention include lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, and gelatin derivatives such as gelatin reacted with anhydrides of dibasic acids, etc., which are commonly used in the art. Any material can be used. The porous silica used in the practice of the present invention is preferably silica obtained by secondary agglomeration of fine silica sol in water. Typical trade names include Cyroid (Fuji Davison Chemical Co., Ltd.) and Mizuka Seal (Mizusawa Chemical Co., Ltd.). Co., Ltd.), Silcron (Nissan Chemical Co., Ltd.), Nipseal (Nippon Silica Industries Co., Ltd.), Fine Seal (Tokuyama Soda Co., Ltd.), Carplex (Shionogi Pharmaceutical Co., Ltd.)
Co., Ltd.) etc. are known. Examples of porous silica with an average particle size of 0.8μ to 2.0μ used in the practice of the present invention include NipSeal E-220, NipSeal E-220A, N-300A (products of Nippon Silica Kogyo Co., Ltd.), and FineSeal T-32 (Tokuyama Co., Ltd.). Soda Co., Ltd. products),
Carplex FPS-1, Carplex FPS-4, Carplex FPS-
7 (these are Shionogi Pharmaceutical Co., Ltd. products), etc. On the other hand, examples of porous silica with an average particle size of 4.0μ to 10.0μ include NipSeal E-50, NipSeal E-100, NipSeal E-150 (products of Nippon Silica Kogyo Co., Ltd.), Thyroid 65, NipSeal 72,
These include 74, 79, 161, 308, and 978 (the above are Fuji Davison Chemical Co., Ltd. products). Porous silica with an average particle size of 0.8μ to 2.0μ used in the present invention and an average particle size
The weight ratio of the porous silica of 4.0μ to 10.0μ is preferably in the range of 20:1 to 3:2, particularly preferably 10:1 to 3:1. It is advantageous to use hardening agents for gelatin in the practice of this invention. The amount of hardening agent for gelatin used is preferably in the range of 0.1% to 40% by weight based on the amount of gelatin used, particularly preferably
A good range is 1.0% to 10% by weight. Gelatin hardeners that can be used in the practice of this invention include N,N'-ethylenebis(vinylsulfonylacetamide), 1,3,5-triacryloyl-hexahydro-S-triazine, and the like. Active vinyl compound, 2,4-dichloro-6-
Active halogen compounds such as hydroxy-S-triazine sodium salt, epoxy compounds such as glycerol triglycidyl ether, 1,6
- Ethyleneimino compounds such as -hexamethylene-N,N'-bisethylene urea, isocyanate compounds such as 1,6-hexamethylene diisocyanate, and other hardening agents for gelatin commonly used in photographic emulsions can be used, but aldehyde Compounds can lead to contamination of the backcoat layer, especially when formalin or formalin-releasing compounds are used in the backcoat layer of a photographic paper, and can fog the adjacent emulsion, and when the paper is a color paper, couplers, especially when the paper is a color paper. Its use should be avoided because it reacts with magenta couplers and causes undesirable coloration. In carrying out the present invention, a thickener may be used as appropriate to adjust the viscosity of the back coat coating solution. Thickeners that can be used in the practice of the present invention include starch, starch derivatives, sodium alginate, guar gum, locust bean gum, xanthancum, hydroxyethylcellulose, carboxymethycellulose, methylcellulose, cellulose sulfate, styrene maleic anhydride, etc. Examples include various polymers, methyl vinyl ether maleic anhydride copolymers, and the like. In carrying out the present invention, toning agents, brighteners, fillers, PH regulators, coating aids, etc. can be used in appropriate combinations. Examples of the hydrophobic support used in the practice of the present invention include resin-coated paper in which a paper substrate is coated on both sides with a film-forming resin such as polyolefin, polystyrene, or polyvinyl chloride, often with a polyolefin resin. can. In particular, polyolefin resin-coated paper is advantageously used because of its good processability. In addition, the resin layer of these resin-coated papers contains white pigments such as titanium oxide, zinc oxide, talc, and calcium carbonate, fatty acid amides such as stearic acid amide and arachidic acid amide, zinc stearate, magnesium stearate, and palmitin. It is preferable to contain various additives such as dispersants such as fatty acid metal salts such as calcium acid salts, pigments and dyes such as ultramarine and cobalt violet, antioxidants, optical brighteners, and ultraviolet absorbers in appropriate combinations. 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. The base paper for the polyolefin resin-coated paper may be ordinary natural pulp paper, synthetic fiber paper, or so-called synthetic paper made of synthetic resin film, but it may also be made of softwood pulp, hardwood pulp, or wood mixed with softwood and hardwood pulp. Natural pulp paper based on 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 . Further, the base paper mainly composed of natural pulp can contain various polymer compounds and additives. For example, starch derivatives, polyacrylamide, polyvinyl alcohol derivatives,
Dry paper strength enhancers such as gelatin, sizing agents such as fatty acid salts, rosin derivatives, dialkyl ketene dimer emulsions, wet paper strength enhancers such as melamine resins, urea resins, and epoxidized polyamide resins, stabilizers, pigments, dyes, Optical brighteners, latex, inorganic electrolytes, PH adjusters, etc. can be contained in appropriate combinations. 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. Various drying devices can be used to dry the applied coating liquid, including hot air dryers such as straight tunnel dryers, arch dryers, air lube dryers, and sine curve air dryers, and dryers that use infrared rays, heated dryers, microwaves, etc. I can give it to you. The silver halide photographic emulsion layer according to the present invention includes various types. Examples include a photographic emulsion layer for enlarged positives, a photographic emulsion layer for contact positives, a photographic emulsion layer for negatives, a color photographic emulsion layer, a photographic emulsion layer for printing, a photographic emulsion layer for direct positives, a photographic emulsion layer for diffusion transfer method, etc. . 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, hexahalogenorhodium () complexes, and hexahalogenorhodium () complexes. High contrast agents such as nucleic acid decomposition products, JP-A-50-147925,
Crystal habit modifiers for silver halide grains such as mercapto heterocyclic compounds described or exemplified in No. 51-107129, colors cited or exemplified in the specifications of JP-A-52-65432 and JP-A-52-88340. Sensitizers, stabilizers, antifoggants, color photographic couplers, hardeners, dihydroxybenzene compounds, coating aids, fogging agents, additives for direct positive photographic emulsions such as direct positive photographic dyes, and 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,
Multi-layer silver halide color photographic materials, which undergo one-bath bleach-fixing treatment after color development, are treated with stabilizers, CD-, CD- (the above two compounds are trade names of Kodatsu Co., Ltd.), droxychrome ( It can be processed with any color developer such as May & Baker Co., Ltd. (trade name). 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, etc.), antifouling agents, PH regulators or PH buffers, dura mater Various compounds such as agents (for example, magnesium sulfate, aluminum sulfate, china alum, etc.), surfactants, etc. can be contained in combination. Also, such one-bath bleach-fix solutions can be used at a variety of PHs, but are useful.
The 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 used as the base paper, and one side of it was coated with 9% by weight titanium oxide and 21% by weight low-density polyethylene for kneading titanium oxide (density
0.918 MI 8.5), 45% by weight low density polyethylene (density 0.918, MI5.0), 25% by weight high density polyethylene (density 0.965, MI7.0), resin thickness 30μm
50% by weight low density polyethylene (density 0.918, MI5.0) on the other side.
50% by weight high density polyethylene (density 0.965,
After corona discharge treatment of the matte surface of a resin-coated paper having a matte resin layer of resin (MI7.0) with a thickness of 30 μm, the coating liquid listed in Table 1 was applied with an air knife coater, dried, and photographed. A support for this purpose was manufactured. The coating amount was 20 g/m ² (moisture).

[Writability evaluation method]

Samples developed with a sheet photographic paper processor were evaluated in the following manner. In order to evaluate the bleeding of the water-based ink, a stamp was stamped using a red Shachihata sol stamp pad. In addition, in order to evaluate the bleeding of the oil-based ink, letters were written with ultra-fine black magic ink and judged. Evaluation criteria: ○No bleeding at all. △It smudges a little, but the letters are not crushed. ×The letters are blurry and cannot be read. To examine the drying properties of the ink, a thin line was drawn with a pilot color pen (black) and rubbed with a finger every minute, and the time until the surrounding area became clean was recorded. To check the writing quality with a pencil, I wrote letters with an HB pencil and judged the writing quality. Evaluation criteria: ○Can write smoothly. △Not smooth. ×The pencil gets caught on the film surface. The results are shown in Table 2.

[Table] As can be seen from Table 2, if the present invention is not followed, no matter which porous silica is used, if the proportion of silica in the whole is small, it will be good against bleeding, but the drying properties of the ink will be poor. bad. On the other hand, when the proportion of silica is high, the drying properties of the ink improve, but at the same time, it becomes more likely to bleed. On the other hand, samples (7) and (8) of the present invention have good ink drying properties and are hard to bleed. Example 2 The curing agent of Example 1 formulation No. (6) was added to N and N, respectively.
N'-ethylenebis(vinylsulfonylacetamide), 1,3,5-triacryloyl-hexahydro-S-triazine, 1,6-hexamethylene-N,N'-bisethyleneurea, 1,6- Similar results were obtained in exactly the same manner as in Example 1, except that hexamethylene diisocyanate, 2,4-dichloro-6-hydroxy-S-triazine sodium salt, and sorbitol tetraglycidyl ether were used. F. Effects of the Invention The present invention achieves both bleeding prevention and ink drying properties, and is excellent as a photographic paper for postcards.

Claims (1)

[Scope of Claims] 1. A resin-coated paper-type photographic support in which both sides of a base paper are coated with resin, has a silver halide photographic constituent layer on one side, and at least gelatin on the opposite side of the support. A photographic paper comprising a back coat layer containing porous silica having an average particle size of 0.8μ to 2.0μ, and porous silica having an average particle size of 4.0μ to 10.0μ. 2 The weight ratio of porous silica with an average particle size of 0.8μ to 2.0μ and porous silica with an average particle size of 4.0μ to 10.0μ is
The photographic paper according to claim 1, which has a ratio of 20:1 to 3:2.