JPH06242550A - Supporting body for photografic printing paper - Google Patents

Abstract

(57) [Summary] [Purpose] No yellowing occurs during the development process of photographic paper.
There is no fog even when printing paper is stored for a long time,
Further, the present invention provides a support for photographic printing paper in which the surface resin coating layer does not crack. A backside resin coating layer made of a film-forming synthetic resin is formed on one surface of a paper substrate, and an electron of a coating composition containing an unsaturated organic compound that can be cured by electron beam irradiation is formed on the other surface of the paper substrate. A linear resin is used to form a multi-layered surface resin coating layer, and the inner resin coating layer adjacent to the paper base is acryloylmorpholine and a hydrogenated polybutadiene chain as the main chain and an acryloyl group at the end. A support for photographic printing paper, comprising an electron beam cured product of a coating composition containing the oligomer having

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 forms a resin coating layer composed of an electron beam cured product of a composition containing an unsaturated organic compound curable by electron beam irradiation (hereinafter referred to as an electron beam curable unsaturated organic compound). The present invention relates to a support material for photographic printing papers, which prevents problems of the support for photographic printing papers, that is, yellowing of a resin coating film due to development processing and cracks generated when the printing paper is bent.

[0002]

2. Description of the Related Art Hitherto, 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 processing liquid is less likely to penetrate into the support during the development and fixing processes as compared with the baryta paper, and therefore the washing time and the drying time are significantly increased. In addition, since the treatment liquid does not penetrate into the paper substrate, expansion and contraction of the support itself is suppressed, and the dimensional stability is excellent.

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 causes foaming in the melt extrusion step to cause film cracking of the resin coating layer. Therefore, there is a disadvantage that the pigment content in the resin coating layer cannot be increased to a sufficient level for improving the hiding power or the resolution. Generally speaking, when titanium dioxide is used as the inorganic white pigment, this is about 20
It is difficult to add it in an amount of more than wt% for the above reasons. Therefore, the photographic printing paper obtained by using such a photographic printing paper support 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). 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 is 20 to 8
It can be increased up to 0% by weight. Therefore, 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.

However, a photographic printing paper produced by coating a photographic photosensitive layer on an electron beam curable resin coating layer cured by electron beam irradiation has a photographic developing chemical on the electron beam curable resin layer in the developing step. Phenomenon that is adsorbed and remains in, and colored yellow after development, that is, yellowing occurs, and on the other hand, the coating film is hard, lacks flexibility, and causes large cracks when the photographic paper is bent, It is also known that this is a big drawback in terms of the quality of photographs.

Use of a specific electron beam-curable polymer or electron beam-curable monomer for preventing yellowing and softening of a coating film is disclosed in, for example, JP-A-59-124336.
No. (acrylic acid ester monomer), JP-A-60-70
No. 446 (urethane resin having a double bond), JP-A-6
1-220121 (diacrylate, triacrylate, epoxidized acrylate), JP-A-61-2365.
No. 47 (tetraacrylate ester), JP-A-62-1
No. 61049 (hexaacrylate ester), JP-A-2-47 (acrylate ester of acrylic acid polymer adduct of polyhydric alcohol), etc.
These methods have not fully solved the above problems.

Further, JP-A-61-270750, JP-A-62-109046, JP-A-62-109047,
JP-A-62-141541, JP-A-62-14154
2 and JP-A-62-141543,
It has been proposed to use an electron beam-curable unsaturated organic compound having a polybutadiene chain, but even when these are used, a large crack occurs when the printing paper is bent,
Also, yellowing is a product that cannot be ignored, and therefore, these have not yet given sufficient problem solution.

Regarding the yellowing of the coating film by the above developing solution,
It has a relationship with the flexibility of the coating film, and shows a tendency to contradict the crosslinking 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 by the developing solution is suppressed to a low level, but the flexibility of the coating film is deteriorated and cracks easily occur Become. In addition, the use of high irradiation dose also causes deterioration of paper strength and paper quality of the paper substrate.

On the other hand, when a low irradiation dose is used and / or an acrylate which gives low cross-linking is used, the flexibility of the coating film is secured to a somewhat preferable level.
The yellowing is greatly increased and worsened.

Therefore, in order to suppress the yellowing due to the development process and to obtain a flexible coating film which does not cause cracks when the printing paper is bent, the electron beam curable unsaturated organic compound is selected and the coating film is crosslinked. It is possible to solve all of the above problems simultaneously and effectively by finding a structure and method of a support that does not cause deterioration in flexibility, paper strength of a paper base, and paper quality even when a necessary and sufficient electron dose is irradiated. It is extremely important to do so.

[0011]

The present invention solves the above-mentioned problems of the prior art, has excellent surface smoothness, retains high water resistance, and cracks in the resin coating layer of the support even when the photographic paper is bent. A photographic printing paper support suitable for producing a photographic printing paper that has excellent photographic characteristics with less deterioration of the paper strength and paper quality of the paper substrate by suppressing yellowing due to development processing at the same time. It is the one we are trying to provide.

[0012]

A photographic printing paper support of the present invention is formed on a paper base and one surface of the paper base.
And a surface resin coating layer made of an electron beam cured product of a composition containing an unsaturated organic compound that is curable by electron beam irradiation as a main component, and a film-forming synthetic resin formed on the other surface of the paper substrate. Two layers having a backside resin coating layer as a main component, the front surface resin coating layer including at least an inner resin coating layer adjacent to the paper base and an outermost resin coating layer arranged on the outermost side. It has the above laminated structure,
And the electron beam curable coating composition forming the inner resin coating layer, acryloylmorpholine, and an oligomer having a hydrogenated polybutadiene chain structure as a main chain and having an acryloyl group at the end, characterized in that To do.

[0013]

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 printing paper produced from a support obtained by coating a paper substrate containing natural pulp as a main component and irradiating it with an electron beam to form an electron beam curable resin coating layer has a yellow color after development. There is a problem of so-called yellowing, which is a phenomenon of coloration. Although the cause of yellowing is not completely clear, it is believed that the developing agent in the photographic developing chemicals remains adsorbed on the support during the development processing step and is oxidized to cause coloration.

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 of the support. Increasing the irradiation electron dose for curing, increasing the amount of crosslinkable polyfunctional unsaturated organic compound monomer or oligomer, and adding a large amount of unsaturated organic compound having a relatively small molecular weight, etc. Is effective. However, all of these methods not only deteriorate the flexibility of the coating film but also increase the generation of fog during long-term storage when used as photographic paper when the electron beam irradiation dose is increased. It also has a drawback that the paper base is turned yellow by the impact of electron beam irradiation.

As a result of various studies on this point, the inventors of the present invention have, as described above, a composition containing, as a main component, an unsaturated organic compound which is formed on at least one surface of a paper substrate and can be cured by electron beam irradiation. The surface resin coating layer formed by subjecting an object to electron beam irradiation curing has a laminated structure of two or more layers, and the electron beam having a high crosslinking density is used for forming the outermost surface resin coating layer located on the photographic emulsion layer side. A composition comprising a curable unsaturated organic compound is used, and further, an inner resin coating layer located adjacent to the paper substrate is provided with acryloylmorpholine and a hydrogenated polybutadiene chain structure as a main chain and an acryloyl group at the end. It has been found that these problems can be effectively solved by forming an electron beam curable coating material containing an oligomer having That. That is, a flexible resin coating layer having a relatively low crosslink density is arranged on the inner side which does not come into contact with the developing solution in the development processing, but a resin coating layer having a high crosslink density is arranged on the outermost side which directly contacts the developing solution. Due to
They succeeded in improving the flexibility and the yellowing prevention property at the same time.

The electron beam curable unsaturated organic compound for forming the inner resin coating layer for imparting the flexibility useful in the present invention is composed of the following compounds. (1) The main chain is hydrogenated polybutadiene and the end has
Oligomer having a liloyl group The main chain is a hydrogenated polybutadiene chain used in the present invention,
The structure of the oligomer having an acryloyl group at the terminal is represented by, for example, the following general formula (1).

[0017]

[Chemical 1]

[Wherein, X and Y in the formula (1) are, independently of each other, a bond containing —O—, —NH—, and a residue of a reaction product of an active hydrogen and an isocyanate compound. And n and m are each independently 1
Represents the above integers. ]

The molecular weight of the oligomer of the above formula (1) is 50.
It is preferably 0 to 5000, and more preferably 1000 to 3000. When the molecular weight of the above-mentioned oligomer exceeds 5,000, the viscosity of the obtained resin becomes excessively high, so that the viscosity when the coating material is prepared remarkably rises and the coating property becomes poor. And if it is less than 500,
The resulting cured product has an excessively high crosslink density, and therefore,
The obtained resin coating layer may become excessively hard and may have poor flexibility.

The content of the oligomer having hydrogenated polybutadiene used in the present invention as the main chain and having an acryloyl group at the terminal in the coating composition for forming the inner resin coating layer is preferably 10 to 80% by weight. , And more preferably 20 to 70% by weight. If the content of the above oligomer is higher than 80%, the viscosity may remarkably increase and the coating performance may deteriorate.
In the following, the curing rate may be lowered and a coating film having sufficient flexibility may not be obtained.

(2) Acryloylmorpholine Acryloylmorpholine acts as a reactive diluent in the electron beam curable coating composition, has a fast curing rate and makes the formed coating film tough. The content of acryloylmorpholine used in the present invention is preferably 10% by weight or more, more preferably 20% by weight or more, in the coating composition for forming an inner resin coating layer. Further, if the content of acryloylmorpholine is less than 10% by weight, the resulting coating film may not be able to be imparted with flexibility with sufficient toughness.

The coating composition for forming an inner resin coating layer of the present invention may contain the following radically polymerizable organic compound, if necessary. The following oligomers and monomers can be used as the radically polymerizable organic compound.

Examples of the oligomer include acrylic or methacrylic acid ester of polyurethane, acrylic or methacrylic acid ester of polyether alcohol, acrylic or methacrylic acid ester of bisphenol A, maleic acid or fumaric acid ester.

As the monomer, styrene, N-vinylpyrrolidone, monofunctional acrylate, monofunctional methacrylate, for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate. , 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, isooctyl acrylate, butoxyethyl acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, benzyl Acrylate, isobornyl acrylate, ethylene Kisaido modified phenoxy acrylate, N, N-dimethylaminoethyl acrylate,
Examples thereof include N, N-dimethylaminoethyl methacrylate, ethylene oxide-modified phenoxylated phosphoric acid acrylate, and ethylene oxide-modified butoxylated phosphoric acid acrylate. In addition to this, Toagosei Kagaku Kogyo Co., Ltd .: Aronix M-101, the same: Aronix M-102, the same: Aronix M-111, the same: Aronix M-113, the same: Aronix M-114,
Same: Aronix M-117, Same: Aronix M-1
52, the same: Aronix M-154 (both are trademarks) etc. can be used.

As the polyfunctional acrylic monomer, the polyfunctional methacrylic monomer, and the polyfunctional vinyl monomer, 1,4-butanediol diacrylate,
1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate Examples thereof include acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and divinylbenzene.

In the present invention, of the surface resin coating layers,
The outermost resin coating layer located on the outermost side and on which the photographic emulsion layer is formed is formed by electron beam curing of the electron beam curable unsaturated organic compound-containing coating composition. The electron beam-curable unsaturated organic compound may be a monomer alone or an oligomer alone, or may be a mixture thereof, as long as it can form a highly crosslinked resin coating layer by electron beam irradiation. The type of these unsaturated organic compounds is also not particularly limited, but it is desirable that the coating composition be composed mainly of a tetrafunctional or higher functional unsaturated organic compound.

The first method for producing the photographic paper support of the present invention having a surface resin coating layer composed of a plurality of layers as described above is a coating for forming an inner resin coating layer on one surface of a paper substrate. To form an inner coating liquid layer, and further by tandem to coat the innermost coating liquid layer with a coating material for forming the outermost resin coating layer to form the outermost coating liquid layer, and to apply an electron beam to this laminate. Irradiation method, that is, 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 the first coating solution layer is irradiated with a first electron beam to cure it. The inner resin coating layer is formed, and then the outermost resin coating layer-forming coating material is applied on the inner resin coating layer in tandem to form the outermost coating liquid layer.
A method of forming an outermost resin coating layer by irradiating the electron beam of
That is, a wet-on-dry method can be used.

As a third method, contrary to the second method, the outermost resin coating layer-forming coating material is applied in advance on a suitable molding surface, for example, a smooth surface such as a metal drum, plastic or process paper. After that, the outermost resin coating layer is formed by irradiating it with the first electron beam, and the coating material for forming the inner resin coating layer is separately applied on one surface of the paper substrate to form the inner coating liquid layer. Next, next, the outermost resin coating layer is superposed on the inner coating liquid layer on the paper substrate, and the second electron beam irradiation is applied to the laminated body to cure the inner coating liquid layer. ,
A method of forming the inner resin coating layer can be used.

As a fourth method, the outermost coating liquid layer on the molding surface in the third method is superposed on the inner coating liquid layer on the paper substrate without electron beam curing, and then the third method is performed. A method of performing the same hardening treatment as that of the above method, that is, a wet-on-wet method is also effective.

Whichever method is used, the coating liquid layer is
By applying the coating in layers or more, it is possible to improve the degree of freedom of the coating method and improve the coating property in the coating of a plurality of times, and to impart a unique function to each layer. Further, the smoothness of the surface of the outermost resin coating layer obtained when the transfer coating (the third and fourth methods) is performed is further improved.

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.
g / m²Is more preferable, and more preferably 15-
50 g / m²Is. This coating amount is 5 g / m²Less than
Is the smoothness and hiding power of the resulting support, and
The resolution of the photographic paper used may be insufficient, and
60g / m²The effect becomes saturated when the number exceeds
As a result, the resin coating layer becomes too thick. Also,
The coating amount of the outer resin coating layer is 0.5 to 15 g / m ²And
Is more preferable, and more preferably 1-5 g / m²And
It This coating amount is 0.5 g / m²Support obtained by less than
The smoothness and yellowing resistance of the body may be insufficient, and
It is 15g / m²Coating obtained when the number exceeds
Membrane flexibility becomes insufficient and creases easily occur
It Therefore, the coating amount of the inner resin coating layer is 4.5 to 5
9.5 g / m²Is preferred and 4-55 g / m
²Is more preferred, and even more preferably 14 to
45 g / m²Is.

In the present invention, the inner resin coating layer located on the paper substrate side of the surface resin coating layer has acryloylmorpholine and hydrogenated polybutadiene chain structure as a main chain capable of forming a flexible resin layer, It is necessary to contain at least one oligomer having an acryloyl group at the end. The inventors of the present invention previously described in Japanese Patent Laid-Open No. 5-2
As described in No. 16163, it was found that an electron beam curable resin having less than 4 functionalities is used as the unsaturated organic compound for the inner resin coating layer, and among them, the unsaturated organic compound is particularly used. By doing so, it is possible to give the photographic paper such flexibility that it does not generate cracks even when it is bent.

The surface resin coating layer of the present invention preferably contains a white pigment for the purpose of improving the sharpness of the photographic printing paper. Titanium dioxide (anatase type and rutile type) is mainly used as the white pigment,
Other than these, barium sulfate, calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide, magnesium hydroxide and the like can be used. Further, the surface of titanium dioxide particles is treated with a metal oxide such as alumina hydroxide, or a silane coupling agent, a titanium coupling agent, or a surfactant is added to improve the dispersibility of the particles. It may be. The content of the white pigment is preferably 20 to 80% by weight of the total solid content of the electron beam curable resin coating layer. If the content is less than 20% by weight, the sharpness of the obtained photographic image on the photographic paper may not be sufficient, and if it exceeds 80% by weight, the flexibility of the obtained resin coating layer is lowered and film cracking occurs. May occur.

To disperse the white pigment in the electron beam curable coating composition 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 and the like can be used.

The resin composition may be applied to the molding surface or the paper substrate surface by, for example, bar coating, blade coating, squeeze coating, air knife coating, roll coating, gravure coating or transfer coating. Etc. may be used. For this purpose, a fountain coater or slit die coater system can be used. Especially when the surface of a metal drum is used as a molding surface, a roll coating method or an offset gravure coating method using a rubber roll as a coating tool is used in consideration of preventing damage to the molding surface. A non-contact type fountain coater or a slit die coater method is advantageously used.

In the present invention, there are four types of methods for forming two or more surface resin coating layers, as described above.
The third method is a transfer coating method, which is more preferable 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 achieved. A transfer coater which can be used for producing the photographic paper support of the present invention is described in JP-A-5-216163.

According to the third method, the electron beam irradiation to the paper substrate can be suppressed to a low level, so that the discoloration of the paper substrate due to the electron beam irradiation can be prevented, and the electron beam to the paper substrate can be prevented. It is also possible to suppress the fog that occurs on photographic paper during long-term storage due to the irradiation with rays.

The electron beam accelerator used for electron beam irradiation is not particularly limited in its system, but for example, an electron beam irradiation device such as a Van de Graaff scanning system, a double scanning system, or a curtain beam system can be used. . Among them, the curtain beam type, which is relatively inexpensive and can obtain a large output, is effectively used. The accelerating voltage during electron beam irradiation is preferably 100 to 300 kV, and the absorbed dose is preferably 0.1 to 6 Mrad, more preferably 0.5 to 5 Mrad.

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 be insufficient. However, in the case of the third method of transfer method in which the second electron beam irradiation is performed after superimposing the cured coating film by the first electron beam irradiation, the first electron beam irradiation to the outermost coating liquid layer is performed. When
By slightly increasing the oxygen concentration in advance to delay the curing and leave room for cross-linking in the superposed inner coating liquid layers, the second outermost layer and the inner layer are irradiated by the second electron beam irradiation to this laminate. The bond between the resins is strengthened, and the adhesiveness is improved. Therefore, in the present invention, the oxygen concentration in the irradiation atmosphere during the first electron beam irradiation of the outermost coating liquid layer is preferably 600 ppm or more.

When the second electron beam irradiation is carried out after superposition, the electron beam curable coating liquid in the inner coating layer does not come into direct contact with the air during the electron beam irradiation. Although it is not necessary to reduce the oxygen concentration in the atmosphere in particular, use an inert gas for the purpose of suppressing ozone generation due to electron beam irradiation or for cooling windows that generate heat when the electron beam passes through. Of course, there is no problem. As the oxygen concentration in the above irradiation atmosphere, the concentrations described in Japanese Patent Application No. 4-132730 and Japanese Patent Application No. 4-210280 can be used.

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 curing resin described above. 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, at least two copolymers 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. If necessary, a small amount of an antioxidant and a lubricant may be added to the polyolefin resin. To form the backside resin coating layer using a polyolefin resin, a usual melt extrusion coating can be used.

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

The paper substrate used in the present invention is usually 50 to 50.
A material having a basis weight of 300 g / m ² and a smooth surface is used. The paper substrate used in the present invention can be selected from those generally used for a photographic printing paper support. As the natural pulp forming the paper substrate, generally,
Widely used are those mainly composed of softwood pulp, hardwood pulp, mixed softwood and hardwood pulp. Further, the paper substrate may contain a filler.

In particular, it is effective to incorporate magnesium hydroxide, oxide, salt or the like into the paper base for the purpose of preventing fog which occurs during long-term storage when used as photographic paper. In addition, the paper substrate contains sizing agents, fixing agents, paper strengthening agents, fillers, antistatic agents, pH commonly used in papermaking.
Additives such as regulators, pigments and dyes may be blended. Further, a surface sizing agent, a surface paper strength agent, a pigment, a dye, an antistatic agent or the like may be appropriately applied on the surface.

[0047]

EXAMPLES The constitution and effects of the present invention will be further described by the following examples, but the scope of the present invention is not limited by these examples.

Example 1 One surface of a paper substrate having a basis weight of 180 g / m ² was subjected to surface activation treatment by corona discharge, and a polyethylene resin was melt-extruded on the surface so that the coating amount was 30 g / m ^2. Coating was performed to form a backside resin coating layer. 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 mixed and dispersed for 1 hour with a paint conditioner, and then cured using a wire bar. the amount of coating is applied so that the 25 g / m ^2, to form an inner coating solution layer.

[0049] Composition 1 Ingredients Blend amount hydrogenated polybutadiene acrylate oligomer 45.0 parts by weight (trademark: TEAI-1000, manufactured by Nippon Soda Co., average molecular weight about 1000) acryloyl morpholine (Trademark: ACMO, Kohjin Co., Ltd.) 27.5 parts by weight of lauryl Acrylate (Trademark: LA, made by Osaka Organic Chemicals) 27.5 parts by weight Titanium dioxide (Trademark: Taipek A-220, made by Ishihara Sangyo) 60.0 parts by weight

Separately from this, a coating composition (composition 2) for forming the outermost resin coating layer having the composition shown below was formed on a molding surface made of the surface of a metal plate plated with chrome with a paint conditioner. After mixing and dispersing for a period of time, 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.

[0051] Composition 2 Ingredients Blend amount pentaerythritol tetraacrylate 100.0 parts by weight (trademark: Beam Set 710, Arakawa Chemical Industries, Ltd.) Titanium dioxide (trademark: TIPAQUE A-220, manufactured by Ishihara Sangyo Kaisha) 60.0 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, and an acceleration voltage of 175 kV and an absorbed dose of 2 Mrad are applied to the laminate from the back of the paper base. The inner coating liquid layer is cured by irradiating it with an electron beam under the conditions described above, and at the same time, the outermost and inner coating liquid layers are bonded and integrated, and then the laminate is peeled from the surface of the metal plate to support the photographic paper It was created.

Using the thus obtained support for photographic printing paper, yellowing after the development treatment and flexibility of the surface resin coating layer were evaluated. The results are shown in Table 1.

The yellowing and the flexibility were evaluated as follows. Yellowing: The test support is treated with a Dust automatic developing machine (trademark: RC
P20, manufactured by Durst Co., Ltd.)
The b value was measured according to APPI-T524 "Lab measuring method", and the value obtained by subtracting the b value before the development processing from the b value after the development processing (Δb value) was evaluated as an index of yellowing. Δ
If the b value is 1.0 or less, it is practical, but if it exceeds 1.0, it is not practical.

Flexibility: The surface resin coating layer of the test support was placed outside, and the support was wound around a round bar having a diameter of 1.0 mm, and the degree of cracking was visually evaluated. 3 which did not crack at all
A point was evaluated as 2 points, and a cracked point was 1 point. Three and two points are practical, but one point is not practical.

Example 2 A photographic printing paper support 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.

[0057] Composition 3 Ingredients Blend amount hydrogenated polybutadiene acrylate oligomer 60.0 parts by weight (trademark: TEAI-1000, manufactured by Nippon Soda Co., average molecular weight about 1000) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 20.0 parts by weight of 2 -Ethylhexyl acrylate 20.0 parts by weight (Trademark: Lightester EH, manufactured by Kyoeisha Yushi) Titanium dioxide (Trademark: Taipaque CR-58, Ishihara Sangyo) 60.0 parts by weight

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. The evaluation results are shown in Table 1.

[0059] Composition 4 Ingredients Blend amount hydrogenated polybutadiene acrylate oligomer 30.0 parts by weight (trademark: TEAI-1000, manufactured by Nippon Soda Co., average molecular weight about 1000) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 35.0 parts by weight of 2 -Ethylhexyl acrylate 35.0 parts by weight (Trademark: Light Ester EH, manufactured by Kyoeisha Yushi) Titanium dioxide (Trademark: Taipaque A-220, Ishihara Sangyo) 60.0 parts by weight

Example 4 A support for photographic printing paper was prepared and evaluated 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. The evaluation results are shown in Table 1.

[0061] Composition 5 Ingredients Blend amount hydrogenated polybutadiene acrylate oligomer 45.0 parts by weight (trademark: TEAI-1000, manufactured by Nippon Soda Co., average molecular weight 1000) acryloyl morpholine (Trademark: ACMO, manufactured by Kojin) 15.0 parts by weight of 2 Ethylhexyl acrylate 25.0 parts by weight (Trademark: Lightester EH, Kyoeisha Oil & Fat) 2-hydroxypropyl acrylate 15.0 parts by weight (Trademark: Lightester HOP-A, Kyoeisha Oil & Fat) Titanium dioxide (Trademark: Taipek A-220, Ishihara Sangyo) ) 60.0 parts by weight

Example 5 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the following composition 6 was used as the coating composition for forming the inner resin coating layer. The evaluation results are shown in Table 1.

[0063] Composition 6 Ingredients Blend amount hydrogenated polybutadiene acrylate oligomer 45.0 parts by weight (trademark: TEAI-3000, manufactured by Nippon Soda Co., average molecular weight about 3000) acryloyl morpholine (Trademark: ACMO, Kohjin Co., Ltd.) 27.5 parts by weight of lauryl Acrylate (Trademark: LA, made by Osaka Organic Chemicals) 27.5 parts by weight Titanium dioxide (Trademark: Taipek CR-58, made by Ishihara Sangyo) 60.0 parts by weight

Example 6 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.

[0065] Composition 7 Ingredients Blend amount caprolactone modified dipentaerythritol hexaacrylate 100.0 parts by weight rate (3 caprolactone-modified acryloyl group-containing, trademark: KAYARAD DPCA-30, manufactured by Nippon Kayaku) Titanium dioxide (trademark: TIPAQUE A -220, Ishihara Sangyo) 60.0 parts by weight

Comparative Example 1 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the hydrogenated polybutadiene acrylate oligomer in the composition 1 was replaced with polybutadiene acrylate (trademark: NISSO PB TEA-1000,
Made by Nippon Soda). The evaluation results are shown in Table 1.

Comparative Example 2 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 5. However, the hydrogenated polybutadiene acrylate oligomer in the composition 6 was replaced with polybutadiene acrylate (trademark: NISSO PB TEA-1000,
Made by Nippon Soda). The evaluation results are shown in Table 1.

Comparative Example 3 A photographic printing paper support was prepared and evaluated in the same manner as in Example 1. However, the hydrogenated polybutadiene acrylate oligomer in the composition 1 is a urethane acrylate oligomer (trademark: New Frontier R-1301,
Manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). The evaluation results are shown in Table 1.

Comparative Example 4 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the acryloylmorpholine in the composition 1 was replaced with polyethylene glycol diacrylate (trademark: KAYARAD PEG400DA, manufactured by Nippon Kayaku).
Replaced with. The evaluation results are shown in Table 1.

Comparative Example 5 A support for photographic printing paper was prepared and evaluated in the same manner as in Example 1. However, the ratio of each component in the composition 1 was changed to hydrogenated polybutadiene acrylate oligomer: acryloylmorpholine: lauryl acrylate: titanium dioxide = 8: 46: 46: 60. Table 1 shows the evaluation results
Shown in.

Comparative Example 6 A photographic printing paper support was prepared and evaluated in the same manner as in Example 1. However, the manufacturing process was performed as follows. The coating composition 1 was applied onto the above-mentioned metal plate molding surface using a wire bar so that the coating amount after curing was 25 g / m ^2, and the surface of the paper substrate was superposed on this coating layer surface, After curing the composition by irradiating an electron beam from the back surface of the paper substrate at an accelerating voltage of 175 kV and an absorbed dose of 2 Mrad, the composition obtained by the above steps was peeled off from the metal plate molding surface, and photographed. A support for photographic paper was prepared. The evaluation results are shown in Table 1.

Comparative Example 7 In the same manner as in Comparative Example 6, a support for photographic printing paper was prepared and evaluated. However, instead of the composition 1, the composition 6 was used. The evaluation results are shown in Table 1.

[0073]

[Table 1]

[0074]

INDUSTRIAL APPLICABILITY The support for photographic printing paper of the present invention can greatly reduce the problem when an electron beam curable resin coating layer is provided, that is, the yellowing of the coating film during development processing. In addition, it is possible to maintain flexibility and is extremely effective in practical use.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshifumi Fujii 1-24-11 Izumitamaro, Iwaki City, Fukushima Prefecture

Claims (1)

[Claims] 1. A surface resin coating comprising a paper substrate and an electron beam cured product of a coating composition containing as a main component an unsaturated organic compound which is formed on one surface of the paper substrate and is curable by electron beam irradiation. And a backside resin coating layer formed on the other surface of the paper substrate and containing a film-forming synthetic resin as a main component, the front surface resin coating layer being at least an inner resin adjacent to the paper substrate. An electron beam curable coating composition having a laminated structure of two or more layers including a coating layer and an outermost resin coating layer arranged on the outermost side, and forming the inner resin coating layer is acryloylmorpholine, A support for photographic printing paper, comprising: an oligomer having a hydrogenated polybutadiene chain structure as a main chain and having an acryloyl group at a terminal.