JPH07270968A - Substrate for photographic printing paper - Google Patents

Abstract

PURPOSE:To provide a substrate capable of producing a photographic printing paper without lacing the surface of an emulsion layer due to the optical interference, high in the sharpness of the picture, and excellent in surface smoothness and surface gloss. CONSTITUTION:A multilayer surface resin coating layer consisting of the electron beam-cured body of the coating composition contg. an unsaturated org. compd. capable of being cured by the irradiation with an electron beam and a pigment is formed on the surface of a sheet-shaped substrate to constitute the substrate for a photographic printing paper. In this case, the pigment content in the outermost layer of the surface resin coating layer is controlled to 25-40wt.% of the total solid weight of the outermost layer, and the pigment content in the inner resin coating layer is made >=10wt.% more than that in the outermost layer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a support for photographic printing paper. More specifically, the present invention provides a photographic print having a surface resin coating layer having a multilayer structure, which is composed of a cured product of an unsaturated organic compound (hereinafter referred to as an electron beam-curable unsaturated organic compound) that can be cured by electron beam irradiation. A photographic paper which is related to a support for paper and in which, when a subcoat layer and a photographic emulsion layer are provided on the surface resin coating layer to make a photographic paper, a stripe pattern due to interference of light generated on the surface of the photographic paper is prevented. The present invention relates to a support for photographic paper.

[0002]

2. Description of the Related Art In recent years, as a support for photographic printing paper, a polyolefin-coated support produced by coating both sides of a substrate made of paper with a polyolefin resin has been widely used. In such a support, since the polyolefin coating layer is hydrophobic, the treatment liquid is less likely to penetrate into the support during the development and fixing processes as compared with the conventionally used baryta paper, and therefore the washing time And that the drying time is significantly shortened, and because the treatment liquid does not penetrate into the paper substrate, it has the advantages that the expansion and contraction of the support itself is suppressed and it has excellent dimensional stability. is doing.

An inorganic white pigment such as titanium dioxide is mixed into the polyolefin resin coating layer of such a support for the purpose of improving the hiding power or resolution, and such a pigment is dispersible in the resin. However, there is a problem in that the volatile component contained in the pigment foams in the melt extrusion process, causing film cracking in the coating layer. Therefore, the pigment content in the coating layer cannot be increased to a level sufficient to improve the hiding power or resolution. Generally speaking, when titanium dioxide is used, it is difficult to add it in an amount of about 20% by weight or more. Therefore, the photographic printing paper obtained by using such a conventional support for photographic printing paper cannot be said to be sufficiently satisfactory in image sharpness.

In recent years, a so-called electron beam curable resin, which is a resin composition which can be cured by electron beam irradiation, has been applied to a support, and an electron beam cured resin layer which has been cured by subjecting it to electron beam irradiation is applied. A photographic printing paper support has been proposed (for example, JP-B-60-17104 and JP-B-60).
-17105 and JP-A-57-49946). In such a photographic printing paper support, it is not necessary to heat and melt the resin composition at a high temperature when forming the coating layer, and the pigment content can be increased to 20 to 80% by weight. The image sharpness of the photographic printing paper obtained by using such a support is remarkably improved as compared with the polyolefin resin-coated photographic printing paper.

In particular, a metal cylindrical rotating body as disclosed in Japanese Patent Publication No. 60-17105 and Japanese Patent Publication No. 4-699.
A sheet-shaped base material coated with an electron beam-curable coating composition is pressed against a very smooth and highly glossy molding surface such as a sheet-shaped film disclosed in No. 32, and then cured by electron beam irradiation. The photographic printing paper support thus obtained also has the advantage that a very good surface property of the molding surface is reflected, and a very high smoothness and high gloss surface property can be obtained.

However, a photographic printing paper support having a coating layer made of such an electron beam curable resin has a high pigment content as described above and has a very good surface property. There was a problem. Sunachiwa,
When a photographic printing paper is prepared by applying a sub-coat layer on a support for photographic printing paper obtained by pressing the molding surface after applying an electron beam curable coating composition, and further forming a photographic emulsion layer thereon. It has become clear that there is a problem that light interference occurs on the surface of the photographic printing paper, and a striped pattern such as a rainbow occurs, and improvement thereof is desired.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above problems of a conventional photographic printing paper support having an electron beam curable resin coating layer, has high image sharpness, surface smoothness, and surface smoothness. It is intended to provide a support for photographic printing paper, which is useful in the production of photographic printing paper, which is excellent in gloss and does not cause a stripe pattern due to light interference.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies to solve the above problems of a photographic printing paper support having a surface resin coating layer made of the above electron beam curable resin. As a result, as the surface resin coating layer on the side where the photographic emulsion layer of the support for photographic paper is formed, at least two or more laminates including an outermost resin coating layer and an inner resin coating layer are used, and an inner resin coating layer is used. It was found that the stripe pattern due to the interference of light is improved by containing more pigment than that in the outermost resin coating layer so that the light is reflected stepwise on the support surface. The present invention has been completed.

That is, the photographic printing paper support of the present invention comprises a sheet-like base material, an unsaturated organic compound which is formed on one surface of the sheet-like base material, and is curable by electron beam irradiation, and a pigment. And a backside resin coating formed on the other surface of the sheet-like substrate and containing a film-forming synthetic resin as a main component. A layer, and the surface resin coating layer is a laminate of at least two layers including an inner resin coating layer adjacent to the sheet-shaped substrate and an outermost resin coating layer arranged on the outermost side. And the blending ratio of the pigment blended in the coating composition forming the outermost resin coating layer is 25 to 4 of the total solid weight of the outermost resin coating layer.
0% by weight, and the blending ratio of the pigment blended in the coating composition forming the inner resin coating layer is represented by the following general formula (1) X ≧ Y + 10 (1) (where X is an inner resin) It represents the weight% of the pigment blended in the coating layer, and Y represents the weight% of the pigment blended in the outermost resin coating layer).

The electron beam curable resin composition used in the surface resin coating layer of the support for photographic printing paper of the present invention on the side where the photographic emulsion layer is formed is an electron beam curable oligomer which is a base resin, It is composed of a combination of monomers used for dilution, various pigments, tint adjusting agents and various additives. The electron beam curable oligomer usually has a high viscosity, and therefore, it is usually diluted with a monofunctional monomer or a polyfunctional monomer to adjust the viscosity before use. However, it does not matter whether the monomer is used alone or the oligomer is used alone.

The unsaturated organic compound which can be cured by electron beam irradiation used in the present invention can be selected from the following compounds. (1) Aliphatic, alicyclic and araliphatic 1 to 6 valent alcohol and polyalkylene glycol acrylate compounds (2) Aliphatic, alicyclic and araliphatic 1 to 6 valent Acrylate compounds obtained by adding alkylene oxide to alcohol (3) Polyacryloylalkyl phosphates (4) Reaction product of carboxylic acid, polyol and acrylic acid (5) Isocyanate, polyol and acrylic acid (6) Reaction product of epoxy compound and acrylic acid (7) Reaction product of epoxy compound, polyol and acrylic acid

Specifically, the electron beam-curable unsaturated organic compound includes methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, stearyl acrylate, N-vinylpyrrolidone, acryloylmorpholine, 2-ethylhexyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, caprolactone modified Tetrahydrofurfuryl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, dicyclohexyl acrylate, isobornyl acrylate, isobornyl methacrylate, benzyl acrylate, benzyl methacrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxypropylene glycol acrylate, poly Chi glycol diacrylate, epichlorohydrin-modified polyethylene glycol diacrylate, nonylphenoxy polyethylene glycol acrylate, ethylene oxide-modified phenoxy acrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate,
1,4-butanediol diacrylate 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate , Ethylene oxide modified trimethylolpropane triacrylate, propylene oxide modified trimethylolpropane triacrylate,
Neopentyl glycol modified trimethylolpropane diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, caprolactone modified dipentaerythritol hexaacrylate, polyoxy Ethylene epichlorohydrin modified bisphenol A diacrylate, ethylene oxide modified bisphenol A diacrylate, propylene oxide modified bisphenol A diacrylate, neopentyl glycol diacrylate, hydroxybivalic acid ester neopentyl glycol diacrylate, ethylene oxide modified phenoxyphosphoric acid acrylate Ethylene oxide-modified phthalic acid acrylate, polybutadiene acrylate, and tris (acryloyloxyethyl) is preferably selected from the isocyanurate.

The surface resin coating layer of the present invention contains a pigment for the purpose of improving the sharpness when a photographic emulsion layer is formed on the surface resin coating layer to obtain a photographic paper. As the pigment, titanium dioxide (anatase type and rutile type), barium sulfate,
White pigments such as calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide, and magnesium hydroxide can be used, but titanium dioxide is advantageous in terms of hiding power.

Among the resin coating layers forming the surface resin coating layer, the blending ratio of the pigment blended in the electron beam curable coating composition forming the outermost resin coating layer is 25% of the total solid content of the coating layer. It is preferably ˜40% by weight. If the content of the pigment to be blended is less than 25% by weight, the sharpness of the obtained photographic image on the photographic paper is not sufficient, and if it exceeds 40% by weight, light interference may occur when the photographic paper is produced. Stripes occur.

On the other hand, the blending ratio of the pigment blended in the electron beam curable coating composition forming the inner resin coating layer is preferably 35 to 80% by weight of the total solid content of the coating layer, and more preferably the maximum. It is preferable that the mixing ratio is 10% by weight or more added to the mixing ratio of the pigment mixed in the electron beam curable coating composition forming the outer resin coating layer. When the content of the white pigment to be blended is less than the blending ratio of 10% by weight to the blending ratio of the pigment to be blended in the outermost resin coating layer, a striped pattern is generated due to light interference of the obtained printing paper. If the pigment blending ratio of the inner resin coating layer is less than 35% by weight, the sharpness of the photographic image is not sufficient, and if it exceeds 80% by weight, the resin coating layer obtained is too sharp. Flexibility may be reduced and film cracking may occur.

To disperse the pigment in the electron beam-curable unsaturated organic compound as described above, a three roll mill (three roll mill), two roll mill (two roll mill), cowles dissolver, homomixer, sand grinder, A planetary mixer, an ultrasonic disperser or the like can be used.

The method for applying the resin composition to the surface of the sheet-shaped substrate is, for example, bar coating method, air doctor coating method, blade coating method, squeeze coating method, air knife coating method, roll coating method, gravure coating method. Any of the transfer coating method and the like may be used. For this purpose, a fountain coater or slit die coater system can be used.

In the support for photographic printing paper of the present invention, the total coating amount of the surface resin coating layer is 5 to 60 after curing.
It is preferably g / m ² , more preferably 15 to 5
It is 0 g / m ² . When the coating amount is less than 5 g / m ² , the smoothness and hiding power of the resulting support and the resolution of the resulting photographic paper may be insufficient, and it is 6
If it exceeds 0 g / m ² , the effect will be saturated, and the resin coating layer will be too thick, and sufficient curing may not be achieved by low-power electron beam irradiation. The coating amount of the outermost resin coating layer is preferably 0.5 to 15 g / m ^2, more preferably 1 to 5 g / m ^2.

The electron beam accelerator used for the electron beam irradiation is not particularly limited in its method, and for example, an electron beam irradiation device such as a van de Graaff scanning method, a double scanning method, a curtain beam method can be used. However, among them, the curtain beam type, which is relatively inexpensive and can obtain a large output, is advantageously used. The acceleration voltage during electron beam irradiation is preferably 100 to 300 kV, and the absorbed dose is 0.1 to 6 Mr.
Ad is preferable, and 0.5 to 5 Mrad is particularly preferable.

It is generally said that the oxygen concentration in the atmosphere during electron beam irradiation is preferably 500 ppm or less. This is because when the oxygen concentration exceeds 500 ppm, oxygen acts as a retarder for the polymerization reaction and the curing of the resin composition may become insufficient. However, in the present invention, the oxygen concentration in the electron beam irradiation atmosphere is the oxygen concentration in the electron beam irradiation atmosphere at the time of curing the outermost layer coating solution when produced according to the method described in Japanese Patent Application No. 4-132730. Is preferably 600 ppm or more.
Further, when the electron beam irradiation is performed again after being superposed on the inner resin coating liquid layer, the electron beam curable coating liquid in the inner coating layer does not come into contact with linear air during the electron beam irradiation,
Therefore, it is not necessary to particularly reduce the oxygen concentration in the atmosphere during electron beam irradiation, but it is not necessary for the purpose of suppressing ozone generation due to electron beam irradiation or for cooling windows that generate heat when the electron beam passes. Of course, there is no problem in using the active gas.

The film-forming synthetic resin used to form the backside resin coating layer of the present invention is a polyolefin resin used in the production of conventional photographic paper supports, or the electron beam curable resin described above. Etc. can be used.

The polyolefin resin for forming the backside resin coating layer includes homopolymers of ethylene, α-olefins such as propylene, copolymers of at least two of the above olefins, and various polymers of these. It can be selected from a mixture of at least two kinds. Particularly preferred polyolefin resins include low density polyethylene, high density polyethylene, linear low density polyethylene,
And mixtures thereof. The molecular weight of the polyolefin resin is not particularly limited, but is usually 20,000 to 20.
Those in the range of 10,000 are used.

The polyolefin resin, if necessary,
A small amount of antioxidant and lubricant may be added. In order to form the backside resin coating layer using the polyolefin resin, a usual melt extrusion coating can be used. Further, as the electron beam curable unsaturated organic compound for forming the back surface resin coating layer, all the compounds used for forming the above surface resin coating layer can be used. Further, the method of forming the back surface resin coating layer can be performed in the same manner as in the case of the front surface resin coating layer described above.

The weight of the backside resin coating layer is not particularly limited, but it is generally preferably in the range of 10 to 40 g / m ² . The backside resin coating layer is provided for the purpose of preventing penetration of the developer into the support during development and preventing twisting and curling caused by contraction of the resin coating layer during electron beam irradiation.

In the present invention, as the sheet-like base material, a paper base having a weight of 50 to 300 g / m ² and having a smooth surface is used as a base paper. As the natural pulp forming the paper substrate, generally, those containing, as a main component, softwood pulp, hardwood pulp, mixed softwood hardwood pulp, etc. are widely used.

Further, the paper substrate may be mixed with additives such as a sizing agent, a fixing agent, a paper strength enhancer, a filler, an antistatic agent, a pH adjusting agent, a pigment and a dye which are generally used in papermaking. Good. Further, a surface sizing agent, a surface paper strength agent, an antistatic agent, etc. may be appropriately applied to the surface. Further, the paper substrate may contain a magnesium compound for the purpose of preventing fog that occurs during long-term storage when used as photographic paper.

Furthermore, there is no problem in using a plastic film or so-called synthetic paper as a sheet-shaped substrate. For example, a film formed by a melt extrusion method of a thermoplastic resin composition containing a polyolefin resin such as polypropylene resin or polyethylene resin can also be used as a sheet-shaped substrate. In addition, for plastic films and so-called synthetic papers used as sheet-shaped substrates, pigments (clay, talc, kaolin, calcium carbonate, titanium dioxide, magnesium hydroxide, etc.),
One or more kinds of dispersants (metal soaps such as zinc stearate and various surfactants) and colored pigments may be contained.

[0028]

EXAMPLES The constitution and effects of the present invention will be described in more detail with reference to the following examples, but the present invention is of course not limited to these embodiments.

Example 1 A paper base material having a basis weight of 180 g / m ² was used as a sheet-like base material, and one surface of the base material was subjected to surface activation treatment by corona discharge, followed by coating with a polyethylene resin. Is 30
A backside resin coating layer was formed by coating by a melt extrusion coating method so as to be g / m ² . Then, on the other surface of the paper substrate, an inner resin coating layer-forming coating composition (composition 1) having the composition shown below was applied 1 by a paint conditioner.
After mixing and dispersing for a period of time, a wire bar was used for coating so that the coating amount after curing would be 25 g / m ² , to form an inner coating liquid layer.

[0030] Composition 1 Ingredient weight urethane acrylate oligomer 39.0 parts by weight (trademark: Beam Set 550B, manufactured by Arakawa Chemical Industries) bifunctional acrylate monomer 26.0 parts by weight (trademark: M-220, manufactured by Toagosei) Titanium dioxide 35.0 parts by weight (Trademark: TAIPAKE A220, made by Ishihara Sangyo)

Separately from this, an outermost resin coating layer-forming coating composition (composition 2) having the following composition was applied on the surface of a molding substrate made of a chromium-plated metal plate with a paint conditioner. After mixing and dispersing for 1 hour, coating was performed using a wire bar so that the coating amount after curing was 3 g / m ² , to form the outermost coating liquid layer. Next, this outermost coating liquid layer was irradiated with an electron beam under the conditions of accelerating voltage: 165 kV and absorbed dose: 3 Mrad to cure the coating liquid layer to form an outermost resin coating layer.

[0032] Composition 2 Ingredient weight Pentaerythritol tetraacrylate 75.0 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) Titanium dioxide (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo Kaisha) 25.0 parts by weight

Next, the outermost resin coating layer and the inner coating liquid layer on the paper base are superposed on a metal plate for molding, and the laminated body is subjected to an acceleration voltage of 175 kV from the back of the paper base and an absorbed dose. : The inner coating liquid layer is cured by irradiating it with an electron beam under the condition of 2 Mrad, and at the same time, the outermost resin coating layer and the inner coating liquid layer are adhered and integrated, and then the obtained laminated body is subjected to the metal plate surface. Then, the surface resin coating layer was formed by peeling from the substrate to prepare a support for photographic printing paper.

The surface of the surface resin coating layer of the obtained photographic printing paper support was subjected to a corona discharge treatment, and then a 10% gelatin solution was applied so that the coating material after drying would be 0.1 g / m ^2. To form a subbing layer, and then apply a black-and-white photographic emulsion (trademark: Art Emulsion, made by Fuji Photo Film Co., Ltd.) on the subbing layer so that the coating amount after drying is 6 g / m ² , and dry to print. Paper was prepared, and the obtained photographic printing paper was used to evaluate the resolution and the stripe pattern due to the interference of light. The results are shown in Table 1.

The evaluation of the striped pattern due to the resolution and interference of light was performed as follows. Resolution: Photographic paper is exposed using an MTF exposure device,
The resolution was measured at a spatial frequency of 5 lines / mm. A resolution of 60% or more is practical, but a resolution of less than 60% is not practical.

Stripe pattern due to light interference: The striped pattern on the surface of the photographic emulsion layer was visually evaluated. Evaluation was made on a three-point scale, with 3 showing no fringe pattern due to light interference, 2 showing a small amount of light interference, and 1 showing a very small amount. Three and two points are practical, but one point is not practical.

Example 2 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the following composition 3 was used as the coating composition for forming the inner resin coating layer. The evaluation results are shown in Table 1.

[0038] Composition 3 Ingredient weight urethane acrylate oligomer 24.0 parts by weight (trademark: Beam Set 550B, manufactured by Arakawa Chemical Industries) bifunctional acrylate monomer 16.0 parts by weight (trademark: M-220, manufactured by Toagosei) Titanium dioxide 60.0 parts by weight (Trademark: TAIPAKE A220, made by Ishihara Sangyo)

Example 3 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the following composition 4 was used as the coating composition for forming the inner resin coating layer, and the following composition 5 was used as the coating composition for forming the outermost resin coating layer. The evaluation results are shown in Table 1.

[0040] Composition 4 Ingredient weight urethane acrylate oligomer 15.0 parts by weight (trademark: Beam Set 550B, manufactured by Arakawa Chemical Industries) bifunctional acrylate monomer 10.0 parts by weight (trademark: M-220, manufactured by Toagosei) Titanium dioxide 75.0 parts by weight (Trademark: TAIPAKE A220, made by Ishihara Sangyo)

[0041] Composition 5 Ingredient weight Pentaerythritol tetraacrylate 70.0 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) titanium dioxide 30.0 parts by weight (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo)

Example 4 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 2. However, the following composition 6 was used as the coating composition for forming the outermost resin coating layer. Table 1 shows the evaluation results
Shown in.

[0043] Composition 6 Ingredients amount pentaerythritol tetraacrylate 60.0 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) titanium dioxide 40.0 parts by weight (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo)

Comparative Example 1 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the following composition 7 was used as the coating composition for forming the outermost resin coating layer. Table 1 shows the evaluation results
Shown in.

[0045] Composition 7 Ingredients amount pentaerythritol tetraacrylate 100.0 parts by weight (trademark: Beam Set 710, manufactured by Arakawa Chemical Industries)

Comparative Example 2 A photographic printing paper support was prepared and evaluated in the same manner as in Example 1. However, the following composition 8 was used as the coating composition for forming the outermost resin coating layer. Table 1 shows the evaluation results
Shown in.

[0047] Composition 8 Ingredients amount pentaerythritol tetraacrylate 65.0 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) titanium dioxide 35.0 parts by weight (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo)

Comparative Example 3 A photographic printing paper support was prepared and evaluated in the same manner as in Example 1. However, the following composition 9 was used as the coating composition for forming the inner resin coating layer. The evaluation results are shown in Table 1.

[0049] Composition 9 Ingredient weight urethane acrylate oligomer 45.0 parts by weight (trademark: Beam Set 550B, manufactured by Arakawa Chemical Industries) bifunctional acrylate monomer 30.0 parts by weight (trademark: M-220, manufactured by Toagosei) Titanium dioxide 25.0 parts by weight (Trademark: TAIPAKE A220, Ishihara Sangyo)

Comparative Example 4 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the following composition 10 was used as the coating composition for forming the inner resin coating layer. Table 1 shows the evaluation results
Shown in.

[0051] Composition 10 Ingredient weight urethane acrylate oligomer 42.0 parts by weight (trademark: Beam Set 550B, manufactured by Arakawa Chemical Industries) bifunctional acrylate monomer 28.0 parts by weight (trademark: M-220, manufactured by Toagosei) Titanium dioxide 30.0 parts by weight (Trademark: TAIPAKE A220, made by Ishihara Sangyo)

Comparative Example 5 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 2. However, the following composition 11 was used as the coating composition for forming the outermost resin coating layer. Table 1 shows the evaluation results
Shown in.

[0053] Composition 11 Ingredient weight Pentaerythritol tetraacrylate 55.0 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) titanium dioxide 45.0 parts by weight (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo)

Comparative Example 6 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the following composition 12 was used as the coating composition for forming the outermost resin coating layer. The evaluation results are shown in Table 1.

The compositions 12 Ingredient weight Pentaerythritol tetraacrylate 80.0 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) titanium dioxide 20.0 parts by weight (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo)

[0056]

[Table 1]

[0057]

INDUSTRIAL APPLICABILITY The present invention is caused by a problem of a support for a photographic printing paper provided with an electron beam-curable resin coating layer, that is, interference of light generated on the surface of a photographic emulsion layer when the photographic printing paper is produced. It is intended to provide a photographic printing paper support capable of producing a photographic printing paper that can significantly reduce the striped pattern, has high image sharpness, and has excellent surface smoothness and surface gloss. It is extremely effective.

Claims (1)

[Claims] 1. An electron of a coating composition comprising a sheet-shaped base material and an unsaturated organic compound which is formed on one surface of the sheet-shaped base material and is curable by electron beam irradiation and a pigment as main components. A surface resin coating layer made of a line-cured body, and a back surface resin coating layer formed on the other surface of the sheet-shaped substrate, and containing a film-forming synthetic resin as a main component,
The surface resin coating layer is a laminate of at least two layers including an inner resin coating layer adjacent to the sheet-shaped substrate and an outermost resin coating layer arranged on the outermost side, and the outermost resin The coating composition for forming the coating layer has a pigment content of 25 to 40% by weight of the total solid weight of the outermost resin coating layer, and the coating composition for forming the inner resin coating layer. The blending ratio of the pigment to be blended in is represented by the following general formula (1) X ≧ Y + 10 (1) (where X represents the weight% of the pigment blended in the inner resin coating layer, and Y represents the outermost resin coating layer). Weight% of blended pigment
Indicates. ) A support for photographic printing paper, characterized in that