JP3291798B2 - Photographic paper support - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic paper support. More specifically, the present invention provides:
Unsaturated organic compounds that can be cured by electron beam irradiation (hereinafter referred to as
The present invention relates to a photographic printing paper support having a surface resin coating layer composed of a cured product of a composition containing an electron beam-curable unsaturated organic compound as a main component. This suppresses yellowing of the resin coating film, and prevents the occurrence of cracks when the photographic paper is bent.

[0002]

2. Description of the Related Art Heretofore, as a support for photographic printing paper, a polyolefin-coated support produced by coating a polyolefin resin on both sides of a base made of paper has been widely used. In such a support, since the polyolefin coating layer is hydrophobic, the processing solution hardly penetrates into the support during the development and fixing processes as compared with the baryta paper, so that the washing time and the drying time are significantly longer. In addition, since the treatment liquid does not penetrate into the paper substrate, the expansion and contraction of the support itself is suppressed, and there are advantages such as excellent dimensional stability.

[0003] 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 the resolving power. However, there is a problem that the volatile components contained in the pigment are foamed in the melt extrusion step, causing the coating layer to crack. For this reason, the pigment content in the coating layer cannot be increased to a level sufficient for improving the hiding power or the resolving power. Generally speaking, when using titanium dioxide, it is difficult to add it in an amount of about 20% by weight or more. Therefore, the photographic printing paper obtained using such a conventional photographic printing paper support was not sufficiently satisfactory in image sharpness.

In recent years, a so-called electron beam-curable resin composed of a resin composition which can be cured by electron beam irradiation, is applied to a support, and an electron beam-curable resin coating layer cured by applying an electron beam thereto. There has been proposed a photographic printing paper support having the following formula (for example, JP-B-60-17104, JP-B-60-17105, JP-A-57-49946). According to this method, 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. Therefore, the image sharpness of a photographic paper obtained using such a support is remarkably improved as compared with a photographic paper coated with a polyolefin resin.

However, the photographic printing paper manufactured by applying a photographic photosensitive layer on the electron beam cured resin coating layer cured by the electron beam irradiation as described above is coated with a photographic developing chemical in a developing step. It is absorbed and remains on the layer and develops a yellow color after the development process, i.e., yellowing occurs.On the other hand, the coating film is hard and lacks flexibility, and when the photographic paper is bent, large cracks occur. And this is also known to be a major drawback in photographic quality.

[0006] In order to prevent yellowing and to soften the coating film, the use of a specific electron beam curable polymer or an electron beam curable monomer is disclosed in, for example, JP-A-59-124336.
No. (Acrylic acid ester monomer as an electronic curable resin), JP-A-60-70446 (urethane resin having a double bond), JP-A-61-201241 (diacrylate, triacrylate, epoxidized acrylate) And JP-A-61-261047 (tetraacrylate), JP-A-62-161049 (hexaacrylate ester) and JP-A-2-47 (acrylate ester of acrylic acid polymer adduct of polyhydric alcohol). However, these methods have not sufficiently solved the problem.

Further, Japanese Patent Application Laid-Open No. 61-270705, 62-
No. 109046, 62-109647, 62-141
No. 542, No. 62-141542, No. 62-141543
The use of electron beam-curable unsaturated organic compounds containing polybutadiene chains is proposed in No. 5, but these also cause large cracks when the photographic paper is folded, and yellowing is ignored as a product. It is not possible and has not yet solved the problem sufficiently.

Regarding the yellowing of the coating film caused by the above-mentioned developer,
It is related to the flexibility of the coating film and shows a tendency to contradict the crosslink density of the coating film. That is, when a high irradiation dose is used and / or when a polyfunctional acrylate that gives high crosslinking is used, yellowing of the coating film due to the developer is suppressed to a low level, but flexibility of the coating film is deteriorated. Also, when a high irradiation dose is used, the paper strength and paper quality of the paper substrate are also reduced.

On the other hand, when a low irradiation dose is used and / or an acrylate which gives low crosslinking, the flexibility of the coating film is secured to some extent, but the yellowing is significantly increased and deteriorated. Therefore, in order to suppress yellowing due to the development process and obtain a flexible coating film that does not crack when the photographic paper is folded, it is necessary and sufficient to select the electron beam-curable organic unsaturated compound and to crosslink the coating film. Finding a configuration and a method of a support that does not degrade the flexibility, paper strength of a paper substrate, or paper quality even when irradiated with a large electron dose is extremely difficult to solve all of the above problems simultaneously and effectively. It is important.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, has excellent surface smoothness, maintains high water resistance, does not crack even when the photographic paper is bent, and simultaneously develops. An object of the present invention is to provide a photographic printing paper support suitable for producing photographic printing paper having excellent photographic properties with less deterioration of paper base strength and paper quality while suppressing yellowing due to processing. .

[0011]

The photographic printing paper support of the present invention comprises a paper base and an unsaturated organic compound formed on one surface of the paper base and curable by electron beam irradiation. A surface resin coating layer composed of a cured product of a composition containing a component, and a back surface resin coating layer formed on the other surface of the paper base and containing a film-forming synthetic resin as a main component; The resin coating layer has a laminated structure of two or more layers, and the resin coating layer adjacent to the paper base contains acryloyl morpholine and a urethane oligomer, and the urethane oligomer has the following properties: 1) an acryloyl group at a terminal; 2) The number average molecular weight measured by gel permeation chromatography (GPC) is from 2000 to 1 in terms of polystyrene.
2000) 3) The acrylic equivalent represented by the following formula (1) is 1000 to 1000
Acrylic equivalent = A / B (1) A: Number average molecular weight measured by GPC (in terms of polystyrene) B: Number of acryloyl groups in one urethane oligomer molecule Photographic printing paper Support.

[0012]

The structure and operation of the present invention will be described below.
Generally, a composition comprising a commercially available electron beam-curable compound,
A photographic paper manufactured from a support obtained by applying an electron beam to a paper base mainly composed of natural pulp and irradiating it with an electron beam to form an electron beam-curable resin coating is yellow after development. There is a problem of coloring, so-called yellowing. Although the cause of the yellowing is not completely clear, it is considered that the developing agent in the photographic processing chemicals is adsorbed and left on the support in the development processing step, and is oxidized to cause coloring.

Therefore, in order to prevent yellowing, it is sufficient to reduce the adsorption of the developing agent, and for that purpose, it is effective to increase the crosslink density of the coating film on the support. Such as increasing the irradiation electron dose for curing the product, increasing the blending amount of the polyfunctional unsaturated organic compound monomer or oligomer, and blending a large amount of the unsaturated organic compound having a relatively small molecular weight. It is possible to keep yellowing low by means. However, all of these methods not only deteriorate the flexibility of the coating film,
When the electron beam irradiation dose is increased, fogging during long-term storage of photographic paper is increased, and in addition, the impact of electron beam irradiation has the disadvantage of discoloring the base paper yellow. .

As a result of various studies on this point, the present inventors have found that, as described above, a composition containing, as a main component, an unsaturated organic compound formed on at least one surface of a paper substrate and curable by electron beam irradiation. The surface resin coating layer composed of a cured product of the product has a laminated structure of two or more layers, and the outermost resin coating layer located on the photographic emulsion layer side is composed of an electron beam-curable unsaturated organic compound having at least a high crosslinking density. These problems can be effectively solved by using the composition and further using the composition containing an unsaturated organic compound composed of acryloylmorpholine and a specific urethane oligomer in the inner resin coating layer located on the paper substrate side. Was found. In other words, by arranging a resin coating layer having a high crosslink density on the outermost surface that is in direct contact with the developer in the development process, and arranging a flexible resin coating layer having a relatively low crosslink density on the inner side not in contact with the developer, The flexibility and yellowing resistance were simultaneously improved.

The electron beam-curable unsaturated organic compound for forming the inner resin coating layer for imparting useful flexibility to the present invention comprises a urethane oligomer and acryloylmorpholine.

The urethane oligomer has an acryloyl group at the terminal, and its molecular weight is such that the number average molecular weight determined by GPC is 2000 in terms of polystyrene.
ア ク リ ル 12000, and the acrylic equivalent determined by the above formula (1) needs to be 1000０〜6000. When the molecular weight exceeds 12,000, the viscosity of the resin is high,
If the coatability is poor, if it is less than 2000, the crosslink density becomes high, and the resin becomes hard and the flexibility becomes poor. On the other hand, when the acrylic equivalent exceeds 6000, the curing speed becomes high and sufficient flexibility of the coating film cannot be obtained. When the acrylic equivalent is less than 1,000, the crosslinking density becomes high, and the resin becomes hard and the flexibility becomes poor.

The content of the urethane oligomer in the coating composition for forming the inner resin coating layer is preferably 20 to 70% by weight, and more preferably 30 to 60% by weight.
% By weight. When the content of the urethane oligomer is 70% or more, the viscosity becomes extremely high, and the coating performance deteriorates.
% Or less, the curing speed decreases, and sufficient flexibility of the coating film may not be obtained.

Acryloyl morpholine acts as a reactive diluent in coating compositions, has a fast cure rate, and makes the formed coating film tough. The content of the acryloylmorpholine is preferably 10% by weight or more, and more preferably 20% by weight or more, in the coating composition for forming the inner resin coating layer. If the amount is less than 10% by weight, it may not be possible to impart flexibility with sufficient toughness to the coating film.

The inner resin coating layer used in the present invention includes:
If necessary, the following electron beam-curable unsaturated organic compound may be contained. Such an organic compound has a terminal group which generates a radical by electron beam irradiation and undergoes a cross-linking reaction. For example, one organic compound is selected from one acryloyl group, methacryloyl group and vinyl group in one molecule. Monofunctional acrylic monomer having a bond, monofunctional methacrylic monomer, monofunctional vinyl monomer, and 1
It is selected from polyfunctional acrylic monomers and oligomers having a double bond selected from at least two or more acryloyl groups, methacryloyl groups, and vinyl groups in the molecule, methacrylic monomers and oligomers, and vinyl monomers and oligomers.

More specifically, monofunctional acrylic, methacrylic, and vinyl monomers include styrene, N-vinylpyrrolidone, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, isooctyl acrylate, lauryl acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, benzyl Acrylate, isobornyl acrylate, ethylene oxide-modified phenoxy acrylate, , N- dimethylaminoethyl acrylate, it is preferably selected from an alkyl phenoxy polyethylene glycol acrylate.

The polyfunctional acrylic, methacrylic and vinyl monomers are 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6
-Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, diethylene glycol diacrylate,
It is preferably selected from triethylene glycol diacrylate, neopentyl glycol diacrylate diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, divinylbenzene, and the like.

Polyfunctional acrylic oligomers, methacrylic oligomers and vinyl oligomers include polyurethane acrylic or methacrylic acid esters, bisphenol A acrylic or methacrylic acid esters, polyether alcohol acrylic or methacrylic acid esters, maleic acid and fumaric acid. It is preferably selected from acid esters and the like.

In the present invention, the electron beam-curable unsaturated organic compound used in the outermost resin coating layer on which the photographic emulsion layer is formed among the surface resin coating layers is one that can form a highly crosslinked resin layer. For example, a monomer alone, an oligomer alone, or a mixture thereof may be used. The type of the compound is not particularly limited, but it is preferable that the compound is mainly composed of an unsaturated organic compound having four or more functional groups.

The first method for producing the photographic printing paper support of the present invention having a surface resin coating layer composed of a plurality of layers as described above is a method for forming an inner resin coating layer on one surface of a paper substrate. To form an inner coating layer, and further apply an outermost resin coating layer forming paint on the inner coating layer by tandem to form an outermost coating layer, and irradiating the laminate with an electron beam. It can be manufactured by a wet-on-wet method.

As a second method, a coating material for forming an inner resin coating layer is applied to one surface of a paper substrate, and then irradiated with a first electron beam to form an inner resin coating layer. After the coating for forming the outermost resin coating layer is applied on the coating layer by tandem, the laminate is irradiated with a second electron beam to manufacture the laminate, which can be manufactured by a wet-on-dry method.

As a third method, contrary to the second method, a paint for forming the outermost resin coating layer is previously applied to an appropriate molding surface, for example, a smooth surface such as a metal drum, plastic, or process paper. After that, a resin coating layer is formed by irradiating a first electron beam, and then the resin coating layer is transferred and laminated on the coated surface of the paper substrate on which the coating material for forming the inner resin coating layer has been applied. 2 can be manufactured by performing electron beam irradiation.

Further, as a fourth method, transfer coating is used. However, the layers can be manufactured by laminating by a wet-on-wet method, and irradiating the laminated body with an electron beam.

Regardless of the method used, split coating of the coating layer into two or more layers improves the degree of freedom of the coating method in a plurality of coatings, improves the coating properties, and gives each layer its own function. Will help you. When performing transfer coating, the smoothness of the surface of the coating layer is further improved.

In the photographic printing paper support of the present invention, the coating amount of the surface resin coating layer is preferably 5 after curing.
６０60 g / m ² , more preferably 15 to 50 g / m ² . If the coating amount is less than 5 g / m ² , smoothness, hiding power,
When the resolving power is not maintained, and when the resolving power exceeds 60 g / m ² , the effect is saturated, and the resin coating layer may be too thick. The coating amount of the outermost resin coating layer is preferably 0.5 to 15 g / m ^2, more preferably between 1 to 5 g / m ^2. 0.5 / m coating amount
^If it is less than ² , smoothness and anti-yellowing property cannot be secured.
If the amount is more than 0 g / m ² , the flexibility of the coating film cannot be secured, and the film may be broken.

The surface resin coating layer of the present invention preferably contains a white pigment for the purpose of improving the sharpness of photographic paper. As the white pigment, titanium dioxide (anatase type and rutile type) is mainly used, but in addition, barium sulfate, calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide and magnesium hydroxide can be used. is there. Also, the surface of titanium dioxide particles is treated with a metal oxide such as alumina hydroxide, or a silane coupling agent or a titanium coupling agent,
Alternatively, the dispersibility may be improved by adding a surfactant or the like. The content of the white pigment is 20 to 80% by weight based on the total solid weight of the electron beam curable resin coating layer.
It is preferable that If the content is less than 20% by weight, the sharpness of the photographic image on the obtained photographic paper may not be sufficient, and if it exceeds 80% by weight, the flexibility of the obtained resin coating layer decreases, and Cracks may occur.

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

Examples of the method for applying the resin composition to the molding surface or the paper substrate surface include bar coating, blade coating, squeeze coating, air knife coating, roll coating, gravure coating, and transfer coating. Any of these may be used. Further, for this purpose, a fountain coater or a slit die coater method can be used. In particular, when the surface of a metal drum is used as a molding substrate surface, a roll coating method using a rubber roll or an offset gravure coating method is used in order to prevent scratches on the molding surface. Fountain coaters and slit die coater methods of the type are also advantageously used.

In the present invention, there are four methods for forming two or more surface resin coating layers as described above.
The third method is the transfer coating method, and more preferably because the outermost resin coating layer is irradiated with a large amount of electron beams, and the effects of the present invention can be advantageously obtained. The transfer coater which can be used for producing the photographic printing paper support of the present invention is disclosed in Japanese Patent Application No. Hei.
-256445 can be used.

According to the third method, since the dose of electron beam irradiation to the paper substrate can be kept low, it is possible to suppress the discoloration of the paper substrate due to the irradiation of the electron beam, and further, it is possible to suppress the electron irradiation on the paper substrate. It is also possible to suppress fog at the time of long-term storage due to radiation.

The electron beam accelerator used for the electron beam irradiation is not particularly limited. For example, an electron beam irradiation apparatus such as a Van de Graff type scanning system, a double scanning system, and a curtain beam system may be used. Among them, a curtain beam type, which is relatively inexpensive and provides a large output, is advantageously used. The acceleration voltage at the time of 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.

The oxygen concentration in the atmosphere during electron beam irradiation is generally preferably 500 ppm or less. If the oxygen concentration exceeds 500 ppm, oxygen acts as a retarder for the polymerization reaction, and the curing of the resin composition may be insufficient. However, in the case of the third method of the transfer method in which the second electron beam irradiation is performed after the second electron beam irradiation is performed after being superposed on the cured film formed by the first electron beam irradiation, the oxygen concentration is previously set at the time of the first electron beam irradiation. By slightly increasing the curing to delay the curing and leaving room for cross-linking with the subsequently bonded resin layer, the bonding between the resin layers becomes stronger by the second electron beam irradiation after bonding, The adhesion is improved. Therefore, in the present invention, the oxygen concentration in the atmosphere during the first electron beam irradiation is preferably at least 600 ppm. When the second electron beam irradiation is performed after the superposition, the electron beam curing coating liquid does not come into direct contact with air during the electron beam irradiation, and therefore, the oxygen concentration in the atmosphere during the electron beam irradiation is particularly reduced. It is not necessary to use an inert gas for the purpose of suppressing ozone generation due to electron beam irradiation or for cooling a window that generates heat when the electron beam passes, of course.

In the present invention, the film-forming synthetic resin used for forming the backside resin coating layer may be a polyolefin resin used in the production of a conventional photographic paper support, or the above-mentioned electron beam-curable resin. Resin or the like can be used.

Examples of the polyolefin resin for forming the backside resin coating layer include homopolymers of ethylene and α-olefins such as propylene, copolymers of at least two kinds of the ethylene and α-olefin, and
It can be selected from at least two kinds of mixtures of these various polymers. Particularly preferred polyolefin resin,
Low-density polyethylene, high-density polyethylene, linear low-density polyethylene, and mixtures thereof. The molecular weight of the polyolefin resin is not particularly limited.
Those having a range of from 000 to 200,000 are used. If necessary, a small amount of an antioxidant and a lubricant may be added to the polyolefin resin. In order to form a backside resin coating layer using a polyolefin resin, ordinary melt extrusion coating can be used.

When the backside resin coating layer is formed using an electron beam-curable unsaturated organic compound, all the compounds used for forming the above-mentioned frontside resin coating layer can be used. Further, the method of forming the backside resin coating layer may be a laminated structure as in the case of the above-mentioned frontside resin coating layer. The weight of the backside resin coating layer is not particularly limited, but is generally 10 to 40 g /
It is preferably in the range of m ² .

The paper substrate used in the present invention is usually 50 to
A material having a weight of 300 g / m ² and a smooth surface is used. Any paper substrate can be used as long as it is generally used for a photographic paper support. As a natural pulp for forming a paper substrate, generally, a pulp mainly containing a softwood pulp, a hardwood pulp, a softwood pulp mixed pulp, or the like is widely used. A filler can be contained in the paper substrate. In particular, it is effective to contain magnesium hydroxide, oxides, salts, and the like for the purpose of preventing fogging that occurs during long-term storage when made into photographic paper. Further, the paper substrate may contain additives generally used in papermaking, such as a sizing agent, a fixing agent, a paper strength enhancer, a filler, an antistatic agent, a pH regulator, a pigment and a dye.
Further, a surface sizing agent, a surface strength agent, a pigment, a dye, an antistatic agent, or the like may be appropriately applied to the surface.

[0041]

EXAMPLES Hereinafter, the structure and effects of the present invention will be described in more detail with reference to examples, but it is needless to say that the present invention is not limited to these embodiments. In addition, the number average molecular weight in the examples is a value in terms of polystyrene measured by GPC, and the acrylic equivalent is a value obtained by the above-described formula (1).

Example 1 A paper substrate having a basis weight of 180 g / m ² was subjected to a corona discharge treatment on one side, and then a polyethylene resin was melt-extruded thereon so as to have a coverage of 30 g / m ^2. The backside resin coating layer was formed by coating with a coating method.

Next, a coating composition for forming an inner resin coating layer having the following composition (composition 1) was mixed and dispersed on the other surface of the paper substrate for 1 hour with a paint conditioner. Using a wire bar, coating was performed so that the coating amount after curing was 25 g / m ² , to form an inner coating layer.

Separately, a coating composition for forming an outermost resin coating layer having the following composition (composition 2) was formed on the surface of a chromium-plated metal plate used as a molding surface.
After mixing and dispersing for 1 hour with a paint conditioner, this composition was applied using a wire bar so that the applied amount after curing was 3 g / m ² , and then the applied layer was subjected to an acceleration voltage of 165 kv and an absorbed dose. : The coating layer was cured by irradiating an electron beam under the condition of 3 Mrad to form an outermost resin coating layer.

Next, the outermost resin coating layer and the above inner coating layer are superimposed on a metal plate, and are laminated by irradiating an electron beam from the back of the paper substrate under the conditions of an acceleration voltage of 200 kv and an absorbed dose of 2 Mrad. The body was cured and bonded to form a surface resin coating layer combined with the outermost resin coating layer, and the obtained photographic printing paper support was peeled off the laminate from the metal plate surface.

[0046] Composition 1 Ingredients Blend weight urethane resin (Trademark: Beam Set 505B, manufactured by Arakawa Chemical) 50 parts by weight (number average molecular weight of about 6000, acrylic equivalent: 3000 bifunctional acrylate oligomer) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 35 parts by weight Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemical) 15 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

[0047] Composition 2 Ingredients Blend amount pentaerythritol tetraacrylate 100 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) Titanium dioxide (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo Kaisha) 60 parts by weight

The resulting photographic printing paper support was evaluated for its yellowing prevention after development and the flexibility of the surface resin coating layer. Table 1 shows the results.

The evaluation of yellowing prevention and flexibility was carried out as follows. Anti-yellowing property: A test support is used as a dust automatic developing machine (trademark:
RCP20, manufactured by Durst Co.), and the b value was measured according to TAPPI-T524, “Lab measurement method”.
Evaluation was performed using the value obtained by subtracting the value (Δb value) as an index of yellowing. If the Δb value is 1.0 or less, there is practicality.
If it exceeds 0, it is not practical.

Flexibility: The test sample was wound around a round bar having a diameter of 1.0 mm with the surface resin coating layer on the outside of the test support, and the degree of cracking was visually evaluated. 3 that did not crack at all
A three-point evaluation was given, in which two points were scored and slightly cracked, and one point was cracked. Three points and two points are practical, but one point is not practical.

Example 2 A photographic printing paper support was produced 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. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0052] Composition 3 Ingredients Blend weight urethane resin (trademark: UK-6087, manufactured by Mitsubishi Rayon) 50 parts by weight (number average molecular weight: about 10,000, acrylic equivalent: 5000 bifunctional acrylate oligomer) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 35 parts by weight Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemical) 15 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

Example 3 A photographic printing paper support was prepared 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. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0054] Composition 4 Ingredients Blend weight urethane resin (Trademark: New Frontier R-1204, 50 parts by weight manufactured by Dai-ichi Kogyo Seiyaku) (number average molecular weight of about 3400, acrylic equivalent: 1700 bifunctional acrylate oligomer) acryloyl Morpholine (trademark: ACMO, manufactured by Kojin) 30 parts by weight Alkylphenoxypolyethylene glycol acrylate 20 parts by weight (trademark: New Frontier NP-2, manufactured by Daiichi Kogyo Seiyaku) Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

Example 4 A photographic printing paper support was produced in the same manner as in Example 1. However, the following composition 5 was used as the coating composition for forming the inner resin coating layer. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0056] Composition 5 Ingredients Blend weight urethane resin (Trademark: Beam Set 505B, manufactured by Arakawa Chemical) 65 parts by weight (number average molecular weight of about 6000, acrylic equivalent: 3000 bifunctional acrylate oligomer) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 25 parts by weight Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemicals) 10 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 50 parts by weight

Example 5 A photographic printing paper support was produced in the same manner as in Example 1. However, the following composition 6 was used as the coating composition for forming the outermost resin coating layer. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0058] Composition 6 Ingredients Blend weight urethane resin (Trademark: Beam Set 505B, manufactured by Arakawa Chemical) 35 parts by weight (number average molecular weight of about 6000, acrylic equivalent: 3000 bifunctional acrylate oligomer) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 45 parts by weight Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemicals) 20 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

Example 6 A photographic printing paper support was prepared in the same manner as in Example 1. However, the following composition 7 was used as the coating composition for forming the inner resin coating layer. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0060] Composition 7 Ingredients Blend weight urethane resin (Trademark: Beam Set 505B, manufactured by Arakawa Chemical) 50 parts by weight (number average molecular weight of about 6000, acrylic equivalent: 3000 bifunctional acrylate oligomer) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 35 parts by weight 2-ethylhexyl acrylate 15 parts by weight (trademark: 2-ethylhexyl acrylate, monomer, manufactured by Wako Pure Chemical Industries) Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

Example 7 A photographic printing paper support was produced 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 results of the evaluation performed in the same manner as in Example 1.

[0062] Composition 8 Ingredients Blend amount caprolactone modified dipentaerythritol hexa 100 parts by weight of acrylate (3 caprolactone-modified acryloyl group-containing, trademark: KAYARADO DPCA-30, manufactured by Nippon Kayaku) Titanium dioxide (trademark: TIPAQUE A- 220, manufactured by Ishihara Sangyo) 60 parts by weight

Comparative Example 1 A photographic printing paper support was produced 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. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0064] Composition 9 Ingredients Blend weight urethane resin (Trademark: BS-550B, manufactured by Arakawa Chemical) 50 parts by weight (number average molecular weight of about 1900, acrylic equivalent: 630 trifunctional acrylate oligomer) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 35 parts by weight Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemical) 15 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

Comparative Example 2 A photographic printing paper support was produced 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 results of the evaluation performed in the same manner as in Example 1.

[0066] Composition 10 Ingredient Blend weight urethane resin (Trademark: New Frontier R-1301, 50 parts by weight manufactured by Dai-ichi Kogyo Seiyaku) (number average molecular weight of about 2100, acrylic equivalent: 3 700-functional acrylate oligomer) acryloyl Morpholine (trademark: ACMO, manufactured by Kojin) 35 parts by weight Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemical) 15 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

Comparative Example 3 A photographic printing paper support was produced in the same manner as in Example 1. However, the following composition 11 was used as the coating composition for forming the inner resin coating layer. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0068] Composition 11 Ingredient Blend weight urethane resin (Trademark: Beam Set 505B, manufactured by Arakawa Chemical) 50 parts by weight (number average molecular weight of about 6000, acrylic equivalent: 3000 bifunctional acrylate oligomer) isobornyl acrylate 35 Parts by weight (trademark: Light Acrylate IB-XA, manufactured by Kyoeisha Yushi) Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemicals) 15 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

Comparative Example 4 A photographic printing paper support was produced in the same manner as in Example 1. However, the following composition 12 was used as the coating composition for forming the inner resin coating layer. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0070] The composition 12 Ingredients Blend weight urethane resin (Trademark: Beam Set 505B, manufactured by Arakawa Chemical) 50 parts by weight (number average molecular weight of about 6000, acrylic equivalent: 3000 bifunctional acrylate oligomer) Polyethylene glycol diacrylate 35 Parts by weight (trademark: Light acrylate 9EG-A, manufactured by Kyoeisha Yushi) Lauryl acrylate (trademark: LA, manufactured by Osaka Organic Chemical) 15 parts by weight Titanium dioxide (trademark: TAIPEK CR-58, manufactured by Ishihara Sangyo) 60 parts by weight

[0071]

[0072]

Comparative Example 5 A photographic printing paper support was produced in the same manner as in Example 1. However, the manufacturing process was performed as follows. The paint of the composition 1 was applied on the surface of the above-mentioned metal plate molding surface using a wire bar so that the applied amount after curing became 25 g / m ^2, and the surface of the paper substrate was superimposed on this applied layer surface. Then, the composition was cured by irradiating an electron beam from the back surface of the paper substrate under the conditions of an acceleration voltage of 200 kv and an absorbed dose of 2 Mrad to prepare a support for photographic printing paper. The obtained laminate was peeled off. Table 1 shows the results of tests performed in the same manner as in Example 1.

Comparative Example 6 A photographic printing paper support was produced in the same manner as in Comparative Example 5 . However, Composition 3 was used in place of Composition 1. Table 1 shows the results of tests performed in the same manner as in Example 1.
Shown in

Comparative Example 7 A photographic printing paper support was produced in the same manner as in Comparative Example 5 . However, Composition 4 was used instead of Composition 1. Table 1 shows the results of tests performed in the same manner as in Example 1.
Shown in

Comparative Example 8 A photographic printing paper support was produced in the same manner as in Comparative Example 5 . However, Composition 2 was used instead of Composition 1. Table 1 shows the results of tests performed in the same manner as in Example 1.
Shown in

[0077]

[Table 1]

[0078]

The photographic printing paper support of the present invention can greatly reduce the problem of providing an electron beam-curable resin coating layer, that is, the yellowing of a coating film during development processing. In addition, it can maintain flexibility and is extremely useful in practical use.

Continuation of front page (56) References JP-A-1-239549 (JP, A) JP-A-59-124336 (JP, A) JP-A-60-70446 (JP, A) JP-A-4-322246 (JP) JP-A-57-49946 (JP, A) JP-A-4-22943 (JP, A) JP-A-4-234754 (JP, A) JP-A-6-59389 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03C 1/79

Claims (1)

(57) [Claims] 1. A paper substrate, and a surface resin coating layer formed on one surface of the paper substrate and comprising a cured product of a composition containing an unsaturated organic compound curable by irradiation with an electron beam as a main component. Having a back surface resin coating layer formed on the other surface of the paper substrate and containing a film-forming synthetic resin as a main component, wherein the surface resin coating layer has a laminated structure of two or more layers, and The resin coating layer adjacent to the paper substrate contains acryloylmorpholine and a urethane oligomer, and the urethane oligomer has the following properties: 1) an acryloyl group at an end; 2) measured by gel permeation chromatography (GPC). Number average molecular weight is 2000-1 in polystyrene conversion
2000) 3) The acrylic equivalent represented by the following formula (1) is 1000 to 1000
Acrylic equivalent = A / B (1) A: Number average molecular weight measured by GPC (in terms of polystyrene) B: Number of acryloyl groups in one urethane oligomer molecule Photographic printing paper Support.