JPH0638153B2 - Support for photographic paper - Google Patents

Description

TECHNICAL FIELD The present invention relates to a support for photographic printing paper. More specifically, the present invention relates to a photographic paper support having improved adhesion to an adhesive tape for connecting photographic paper.

[Conventional technology]

Conventionally, baryta paper has been used as a support for photographic printing paper, but in recent years, a water-resistant support in which a coating layer made of a polyolefin resin is provided on both surfaces of a base made of paper has come to be used. This water resistant support has advantages such as shortening the washing and drying time during development, eliminating the need for ferrotype, saving chemical consumption, maintaining high level of rigidity and various strengths, and less stains due to chemical penetration. have.

High-purity and high-whiteness pulp that does not substantially contain impurities is used for the paper substrate of the support, and strong size treatment to prevent stains due to chemical penetration from the edge part,
Rigidity enhancement treatment, antistatic treatment, etc. are applied.

In addition, the polyolefin layer forming the surface of the support to be coated with the photographic emulsion (hereinafter referred to as the back surface) has good photographic suitability such as whiteness, opacity and fog prevention.
Various additives such as titanium oxide, colored dyes, fluorescent whitening agents, antioxidants, antifoggants and the like are kneaded. On the other hand, a polyolefin resin layer having a slightly higher density than the resin used on the front surface side is used as a curl prevention measure in the polyolefin resin layer forming the surface of the support opposite to the surface to be coated with the photographic emulsion (hereinafter referred to as the back surface). And, it has a proper matte finish to make it paper-like. However, it is usual that no treatment is applied to the resin or the surface of the resin layer.

Recently, problems such as fogging due to discharge during roll unwinding and stacking failure after cutting occur due to static electricity accompanying the increase in cutting speed in a color photographic laboratory. Further, with the advent of the disc film camera, there are problems that the printing tape on the back side of the printing paper has poor printability and the print-fixability at the time of development, that is, ink drops.

In order to solve such a problem, for example, JP-A-59-1
As disclosed in Japanese Patent No. 14536, an attempt to apply a minute amount of a very fine pigment and various conductive agents to the back surface of a support by using an adhesive in order to prevent electrification and improve printability and print fixability. Is being done. However, in this case, depending on the type of pigment and the type of adhesive, the adhesiveness between the obtained photographic printing paper and the adhesive tape for connecting it may be poor. In particular, when developing processing after connecting multiple sheets of photographic printing paper with adhesive tape, the edge of the adhesive tape is affected by a chemical such as a developer, and the adhesive tape is easily peeled off from the photographic paper. This causes a problem that the photographic printing papers are disconnected from each other during the processing.

[Problems to be solved by the invention]

An object of the present invention is to provide a support capable of eliminating the above-mentioned drawbacks of conventional printing papers and obtaining a photographic printing paper excellent in adhesiveness to an adhesive tape.

[Means for solving problems]

The support for photographic printing paper of the present invention comprises a substrate made of paper and a coating layer made of a polyolefin resin formed on both sides of the paper substrate, and the surface of the support on which the photographic emulsion layer is to be formed. 2-80% by weight of zinc hydroxide, on the opposite side of
An adhesive resin layer containing at least one pigment selected from zinc oxalate and zinc sulfide is 0.2 to 5 g / m 2.
It is characterized by being formed with a dry weight of ² .

The support of the present invention comprises a paper substrate, a polyolefin resin coating layer formed on both surfaces thereof, and a zinc pigment-containing adhesive resin formed on the back surface (the surface opposite to the surface coated with a photographic emulsion), as described above. And a layer.

The base paper constituting the paper base used in the support of the present invention may be one commonly used in photographic printing paper supports, for example, natural pulp paper, synthetic pulp paper, a mixture of natural pulp and synthetic pulp. In addition to papermaking, various types of laminated paper can be used. It is also possible to add additives such as a sizing agent, a fixing agent, a paper-strengthening agent, a filler, an antistatic agent and a dye, which are generally used in papermaking, to this base paper,
It is also possible to appropriately apply a surface sizing agent, a backing paper strength agent, an antistatic agent, etc. on the surface.

The polyolefin resin used for coating both sides of the paper substrate can be selected from α-olefin homopolymers such as polyethylene and polypropylene, α-olefin copolymers and mixtures of these various polymers. Particularly preferred polyolefin resin is low density polyethylene,
High density polyethylene and mixtures thereof. Although the molecular weight of the polyolefin resin is not particularly limited, it is usually
It may be in the range of 20.000 to 200.000.

It is already known to add various additives such as a white pigment, a colored pigment, a fluorescent whitening agent, and an antioxidant to a polyolefin resin, and in the present invention, the polyolefin of the surface on which the photographic emulsion is coated is also known. It does not matter at all if these additives are added to the layer.

The zinc pigment used in the present invention is composed of at least one selected from zinc hydroxide, zinc oxalate and zinc sulfide, but in addition to it, very fine silica, clay, carbonic acid conventionally used. Calcium, amorphous silica, amorphous aluminum silicate, amorphous calcium silicate and the like may be mixed in the adhesive resin layer, preferably in the range of 20 to 80% by weight.

The zinc pigment and the additional pigment are preferably those having a particle size of about 0.01 μm to 2 μm micron.

In the present invention, the zinc pigment is contained in the adhesive resin layer in an amount of 2 to 80.
It is contained in a mixed amount within the range of, preferably, 5 to 50% by weight. When the amount of the zinc pigment mixed is less than 2% by weight, the adhesiveness of the obtained adhesive resin layer to the adhesive tape becomes practically insufficient, and when it is more than 80% by weight, the mechanical strength of the obtained adhesive resin layer is high. The strength is practically insufficient.

The adhesive resin constituting the matrix of the adhesive resin layer of the present invention is synthetic rubber, polyvinyl acetate, vinyl acetate-acrylic acid ester copolymer, vinyl acetate-ethylene copolymer, polyacrylic acid ester, polyvinyl chloride, And water-insoluble resins such as vinyl chloride-vinylidene chloride copolymer, and water-soluble resins such as water-soluble polyester, water-soluble acrylic resin, casein, gelatin, oxidized starch, and polyvinyl alcohol. Generally, the water-soluble resin is used in the state of latex or emulsion, and the water-soluble resin is used in the state of aqueous solution.

To form the adhesive resin layer, a coating solution having a desired composition is prepared, and this is applied to the back surface of the support at the same time as the formation of the polyolefin resin coating layer or after that. The coating method is not particularly limited, and any of ordinary bar coating, gravure coating, air knife coating, blade coating and the like may be adopted.

The adhesive resin layer is formed so that the dry weight thereof is 0.2 to 5 g / m ² , and preferably 0.5 to ² g / m ² . If this dry weight is less than 0.2 g / m ² , the adhesiveness of the resulting adhesive resin layer to the adhesive tape will be inadequate for practical use, and if it is more than 5 g / m ² , the feel and appearance of the back surface of the support will be normal. It has the drawback that it is different from those of paper and the manufacturing cost is also high.

〔Example〕

Examples 1 to 4 and Comparative Examples 1 to 4 In each of Examples 1 to 4 and Comparative Examples 1 to 4, 175 g / m ² of base paper was coated on both sides with 30 g / m ² of polyethylene. After performing the corona discharge treatment on the polyethylene layer, the composition (1), (2), (3), (4),
The coating solutions (5), (6), (7), and (8) were applied with a bar coater to a dry weight of 1 g / m ² , and dried at a drying temperature of 70 ° C. and a drying time of 60 seconds.

After that, a 25 mm wide adhesive tape (NO.8422 manufactured by 3M) was attached to the coated back surface of the support, and 1 minute later, the tape was peeled 180 ° in the opposite direction in the developer for color photographic paper, and then peeled off. The adhesiveness to the adhesive tape was evaluated by the peeling (resistive) stress. The results are shown in Table 1.

Composition of coating liquid (1) -Example 1 Composition of coating liquid (2) -Example 2 Composition of coating liquid (3) -Example 3 Composition of coating liquid (4) -Example 4 Composition of coating liquid (5) -Comparative example 1 Composition of coating liquid (6) -Comparative example 2 Composition of coating liquid (7) -Comparative example 3 Composition of coating liquid (8) -Comparative example 4 The trade names of the chemicals used in the above coating solutions are as follows.

Colloidal silica (Ludox-AM-Dupont) Amorphous aluminum silicate (Persilex-Burges) SBR latex (JSR-0662-Nippon Synthetic Rubber) Acrylic ester emulsion (AE-315-Nippon Synthetic Rubber) Vinyl acetate emulsion (Movinyl-630-Hoechst Japan) zinc sulfide (reagent), zinc hydroxide (reagent) zinc oxalate (reagent) In Table 1, the larger the peel stress, the greater the adhesiveness of the adhesive resin layer to the adhesive tape.

The adhesive tape peeling stress of the adhesive resin layers of Examples 1 to 4 according to the present invention was 450 to 650 g, and that of Comparative Example was 15
It has been shown to have significantly higher adhesion compared to ~ 190 g weight.

〔The invention's effect〕

In the support for photographic printing paper of the present invention, by containing a specific amount of a specific zinc pigment on the back side of the support,
Excellent adhesion to an adhesive tape can be imparted to photographic printing paper.

Continuation of the front page (56) Reference JP 61-259246 (JP, A) JP 49-80149 (JP, A) JP 60-100144 (JP, A) JP 58-184144 (JP , A) JP 50-160381 (JP, A) JP 61-28983 (JP, B2) JP 55-5104 (JP, B2) JP 56-53746 (JP, B2)

Claims (3)

[Claims] 1. A photographic printing paper support comprising a substrate made of paper and a coating layer made of a polyolefin resin formed on both sides of the paper substrate. The photographic emulsion layer of the support is formed. On the opposite side of the power side, 2-80% by weight,
An adhesive resin layer containing at least one pigment selected from zinc hydroxide, zinc oxalate and zinc sulfide,
A support for photographic printing paper, characterized in that it is formed with a dry weight of 0.2 to 5 g / m ² . 2. The support according to claim 1, wherein the content of the pigment contained in the adhesive resin layer is in the range of 5 to 50% by weight. 3. The dry weight of the adhesive resin layer is 0.2 to 2 g.
Support according to claim 1 in the range of / m ² .