JPH08240881A - Support for photographic paper - Google Patents

Abstract

(57) [Summary] (Revised) [Purpose] Support for photographic printing paper that has excellent image sharpness, maintains the surface properties of the electron beam curable resin coating layer under various humidity conditions, and has excellent photographic characteristics. Provide the body. A surface resin coating layer made of a cured product of a composition containing as a main component an unsaturated organic compound curable by electron beam irradiation is formed on one surface of a paper substrate, and the other surface of the paper substrate is formed. And a backside resin coating layer containing a film-forming synthetic resin, wherein the front surface resin coating layer contains an unsaturated organic compound curable by electron beam irradiation according to (1) below. The moisture permeability is 80 [g
/ M ² · 24 hours] (measurement conditions: 25 ° C, 90% RH)
It is the following.

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 is a photographic print having a surface resin coating layer composed of a 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 for paper, which has good image sharpness, does not have wrinkle-like wrinkles on the surface, has good surface properties, and has little change in surface condition due to changes in atmospheric humidity.

[0002]

2. Description of the Related Art Conventionally, as a support for photographic printing paper, a polyolefin-coated support produced by coating both sides of a paper base with a polyolefin resin has been widely used. Since the polyolefin coating layer of the support is hydrophobic, compared to baryta paper,
The processing liquid hardly penetrates into the support during development and fixing processing,
Therefore, there is an advantage that the washing time and the drying time are significantly shortened, and since the treatment liquid does not penetrate into the paper substrate, the expansion and contraction of the support is suppressed, and the dimensional stability is excellent. It has advantages such as

An inorganic pigment such as titanium dioxide is mixed in the polyolefin resin coating layer of such a support for the purpose of improving the hiding power or resolution, but such a pigment has a dispersibility in the resin. In addition, there is a problem in that the volatile component contained in the pigment causes foaming in the melt extrusion step to cause film cracking in the resin coating layer. Therefore, there is a disadvantage that the pigment content in the coating layer cannot be increased to a sufficient level for improving the hiding power or resolution. Generally speaking, when titanium dioxide is used as the inorganic white pigment, it is difficult to add it in an amount of about 20% by weight or more for the above reason. 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, Japanese Patent Publication No. 60-17104, Japanese Patent Publication No. 60-17105, and Japanese Unexamined Patent Publication No. 57-4.
In 9946 and JP-A-5-119431, a resin composition that can be cured by electron beam irradiation (hereinafter referred to as electron beam curable resin) is applied to a support, and electron beam irradiation is applied to the support. A photographic paper support having a cured electron beam curable resin layer has been proposed. According to this method, it is not necessary to heat the electron beam curable resin to a high temperature when forming the coating layer, and the pigment content is 20 to 80% by weight.
Can be increased up to. 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, and since heating and cooling are not performed in the manufacturing process, the photographic printing paper is The surface of the paper is excellent.

However, a photographic printing paper produced by coating a photographic photosensitive layer on an electron beam-curable resin layer cured by electron beam irradiation causes expansion and contraction of the paper substrate due to environmental changes, especially humidity changes, and the electron beam is then irradiated. There is a problem that the surface properties of the cured resin layer deteriorate. This is because when the developed photographic printing paper is left in an environment of high humidity or low humidity, wrinkle-like wrinkles gradually appear on the surface of the resin coating layer, and it has commercial value as a photographic printing paper requiring high surface properties. It is known to decrease significantly.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, is excellent in image sharpness, and maintains the surface property of the electron beam curing resin layer under various humidity conditions, It is an object of the present invention to provide a photographic paper support suitable for producing a photographic paper having excellent photographic characteristics.

[0007]

A photographic printing paper support of the present invention is a paper substrate containing natural pulp as a main component, and is formed on one surface of the paper substrate and cured by electron beam irradiation. Surface resin coating layer made of a cured product of a composition containing as a main component an unsaturated organic compound, and 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. And the water vapor transmission rate of the surface resin coating layer based on JIS Z 0208 is 80 [g
/ M ² · 24 hours] (measurement conditions: 25 ° C, 90% RH)
It is characterized by the following.

The surface resin coating layer in the present invention has the following formula (1):

Embedded image [Wherein, in the formula (1), R ₁ represents a phenyl group or a phenyl group having a substituent, a dicyclopentenyl group or a dicyclopentenyl group having a substituent, a tricyclodecanyl group or a tricyclodeca group having a substituent] R ₂ represents an nyl group, an isobornyl group or an isobonyl group having a substituent, R ₂
Is an alkylene ether group or an alkylene ether group having a hydroxyl group. ] The unsaturated organic compound represented by the formula and curable by electron beam irradiation has a weight ratio of the unsaturated organic compound of the formula (1) to the unsaturated organic compound other than the formula (1) of 20/80 to 80/20. It is preferable that the coating amount of the surface resin coating layer is 10 to 40 g / m < ² >.

Further, the surface resin coating layer in the present invention has a laminated structure of two or more layers including at least an inner resin coating layer adjacent to the paper substrate and an outermost resin coating layer arranged on the outermost side, At least one of the resin coating layers is preferably an electron beam cured product of the unsaturated organic compound represented by the formula (1).

The present inventors obtained by applying an electron beam curable resin to 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. As a result of diligent research on the cause of deterioration of the surface property of the photographic printing paper produced from the different supports due to environmental changes, especially humidity changes, it was found that the cause of the surface property deterioration was expansion and contraction due to the water content change of the paper substrate. .

That is, in general, many coating films formed of electron beam curable resin as a main component allow water vapor to pass through well, so that the paper substrate absorbs moisture and expands under high humidity, and the paper substrate dehumidifies under low humidity. As a result, the surface resin coating layer and the photographic emulsion layer are deformed and the surface property is deteriorated.

In order to solve this problem, since the paper substrate reduces expansion and contraction due to moisture absorption and dehumidification due to environmental changes, particularly humidity changes, the moisture permeability of the coating film on both sides of the paper substrate should be kept low. . Since the backside resin coating layer does not require image sharpness and high gloss, it is possible to arbitrarily select a commonly used film-forming synthetic resin with low moisture permeability, such as polyethylene, which is substantially selected from electron beam curable resins. It is important to reduce the moisture permeability of the formed surface resin coating layer.

Therefore, the moisture permeability of the front surface resin coating layer and the back surface resin coating layer is 80 [g / m ² · 24 hours] (25 ° C,
90% RH) or less, and if it is larger than this value, when the photographic printing paper is left in an environment where the humidity changes, the paper substrate absorbs and dehumidifies in a short time, so that the surface of the photographic printing paper has a contracted surface. Wrinkles occur and the surface properties deteriorate in a short time.

In order to keep the moisture permeability of the surface resin coating layer formed of the electron beam curable resin low, it is effective to increase the crosslink density. For this reason, the electron beam for curing the electron beam curable resin is effective. Irradiation dose, increasing the amount of multifunctional electron beam-curable unsaturated organic compound monomer or oligomer compounded, and increasing the amount of electron beam-curable unsaturated organic compound having a relatively small molecular weight. The water vapor permeability can be suppressed low by such means. However, all of these methods not only reduce the flexibility of the coating film, but when the electron beam irradiation dose is increased,
When used as a photographic printing paper, it has the drawback of increasing fog during long-term storage, and also causing the paper substrate to turn yellow due to the impact of electron beam irradiation, and causing deterioration of paper strength and paper quality.

Further, adding a large amount of a hydrophobic electron beam-curable unsaturated organic compound is also effective in suppressing the moisture permeability to a low level, but since polar bonds such as hydrogen bonds are reduced, the paper substrate It also has the drawback that the adhesion to the surface of the resin is deteriorated and the flexibility of the surface resin coating layer is lost.

As a result of various investigations by the present inventors, as described above, it is formed on at least one surface of the paper substrate and is formed by curing the electron beam curable resin by irradiating it with an electron beam. The surface resin coating layer containing at least one or more kinds of unsaturated organic compounds of the formula (1), and the unsaturated organic compound of the formula (1) and the unsaturated organic compound other than the formula (1) are 20 / It has been found that these problems can be effectively solved by blending in a weight ratio of 80 to 80/20, preferably 30/70 to 70/30. That is, by improving the low moisture permeability and the flexibility of the surface resin coating layer, it has succeeded in simultaneously preventing the deterioration of the surface property due to the humidity change of the photographic printing paper and maintaining the flexibility.

The electron beam curable unsaturated organic compound of the formula (1) of the present invention may be blended with a monomer or oligomer of the electron beam curable unsaturated organic compound other than the formula (1), It is necessary that the content of the unsaturated organic compound of the formula (1) is at least 20% or more, and if it is less than 20%, the viscosity of the coating material becomes too high and the water vapor transmission rate becomes large. Further, the content of the unsaturated organic compound of the formula (1) is 80
%, The curability is poor.

The electron beam-curable unsaturated organic compound used in the present invention can be selected from the following compounds, for example.

Embedded image

[0019]

[Chemical 4]

[0020]

Embedded image

[0021]

[Chemical 6]

[0022]

[Chemical 7]

[0023]

Embedded image

In the present invention, as the electron beam curable unsaturated compound monomer or oligomer used together with the electron beam curable unsaturated organic compound of the formula (1) used in the surface resin coating layer, a crosslinked resin layer is used. As long as it can be formed, it may be a monomer alone, an oligomer alone, or a mixture thereof. There is also no particular limitation on the type of the unsaturated organic compound, but if it is within the range of the content and the coating amount to obtain the moisture vapor transmission rate of the surface resin coating layer of the present invention, it is not necessary to increase the crosslinking density.
An electron beam curable unsaturated organic compound having good flexibility can be selected.

In the surface resin coating layer of the support for photographic printing paper of the present invention, 80 [g / m ² · 24 hours] (25 ° C.,
In order to achieve a water vapor transmission rate of 90% RH) or less, the unsaturated organic compound of the formula (1) is used in an amount of 20 to 80% of the total amount of the electron beam-curable unsaturated organic compound regardless of which coating method is adopted.
% By weight, and the coating amount after curing of the surface resin coating layer is 10 to 40 g / m ² , preferably 15 to 30 g / m ² , which prevents deterioration of surface property due to humidity change and provides flexibility. The effect of holding is obtained. Here, the application amount is 10g
When it is less than / m ² , the water vapor permeability becomes large, the surface property is deteriorated due to the humidity change of the photographic printing paper, and the smoothness, hiding power, and resolution as the support for the photographic printing paper cannot be maintained. On the other hand, if the coating amount is more than 40 g / m ² , the electron beam-curable unsaturated organic compound may be uncured or the cost may increase. Regardless of which coating method is used to form the coating liquid layer of the surface resin, the coating liquid layer is divided into two or more layers, whereby the flexibility of the coating method is improved in a plurality of coatings and the coating property is improved. It is possible to improve the property and give each layer a unique function.

When the surface resin coating layer has a laminated structure of two or more layers including at least an inner resin coating layer adjacent to the paper base and an outermost resin coating layer arranged on the outermost side, the resin is At least one of the coating layers forms a layer having a low water vapor transmission rate, which is composed of an electron beam-curable resin containing the unsaturated organic compound of the formula (1) in an amount of 20 to 80% by weight based on the whole electron beam-curable unsaturated organic compound. As a result, the effect of preventing the deterioration of the surface property due to the change in humidity and maintaining the flexibility can be obtained.

The electron beam curable resin for forming a surface resin coating layer on one surface of a paper substrate of the present invention contains a mixture of an electron beam curable unsaturated organic compound and a white pigment as a main component, and if necessary, The monomer or oligomer of the unsaturated compound,
And additives such as polymerization inhibitors, antioxidants, dyes, coupling agents and surfactants.

The monomer or oligomer of the unsaturated compound used for forming the surface resin coating layer of the present invention is not particularly limited by the number of functional groups and the like, but it has a low cross-linking density for imparting flexibility. Compounds having 4 or less functional groups that give ## STR6 ## are particularly advantageously used for the purposes of the present invention. For example, it can be selected from the following compounds. (1) Aliphatic, alicyclic, and araliphatic alcohol and polyalkylene glycol acrylate compounds (2) Aliphatic, alicyclic, araliphatic alcohol acrylate acrylate acrylates Compounds (3) Polyacryloylalkyl phosphates (4) Reaction product of polybasic acid, polyol and acrylic acid (5) Reaction product of isocyanate, polyol and acrylic acid (6) Epoxy Reaction product of compound and acrylic acid (7) Reaction product of epoxy compound, polyol and acrylic acid

More specifically, as unsaturated compounds, polyoxyethylene epichlorohydrin-modified bisphenol A diacrylate, dicyclohexyl acrylate, epichlorohydrin-modified polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, hydroxybivalic acid are used. Ester neopentyl glycol diacrylate, ethylene oxide modified phenoxyphosphoric acid acrylate, ethylene oxide modified phthalic acid acrylate, polybutadiene acrylate, caprolactan modified tetrahydrofurfuryl acrylate, tris (acryloxyethyl) isocyanurate, trimethylolpropane triacrylate, pentaerythritol Triacrylate, pentaerythritol tetraacryle DOO, polyethylene glycol diacrylate, 1,4-butadiene diol diacrylate, neopentyl glycol diacrylate, and neopentyl glycol-modified trimethylol propane diacrylate, and the like. At least one of these compounds can be used in combination with the formula (1) of the electron beam-curable unsaturated organic compound.

The surface resin coating layer of the present invention preferably contains a white pigment for the purpose of improving the image sharpness of a photographic printing paper. Further, other additives can be contained if necessary.

Titanium dioxide (anatase type and rutile type) is mainly used as the white pigment, and in addition to this, barium sulfate, calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide, magnesium hydroxide and the like are among others. Can also be used.

The content of the white pigment is preferably 20 to 60% by weight of the total solid content of the surface resin coating layer.
If the content is less than 20% by weight, the sharpness of the obtained photographic image on photographic printing paper may not be sufficient, and if it exceeds 60% by weight, the electron beam curable resin has a high viscosity and a uniform surface resin. A coating layer may not be obtained, flexibility may be reduced, and film cracking may occur.

To disperse the white pigment in the electron beam-curable unsaturated organic compound as described above, a three-roll mill (three-roll mill), a two-roll mill (two-roll mill),
Cowles dissolvers, homomixers, sand grinders, planetary mixers, ultrasonic dispersers and the like can be used.

In the present invention, the surface resin coating layer can be advantageously used by the method described in JP-A-5-93984. That is, a coating liquid made of an electron beam curable resin is applied onto a paper substrate to form an inner coating layer, and a coating surface made of an electron beam curable resin is separately applied to a peripheral surface of a metal drum or a molding surface such as a plastic film surface. The liquid is applied and cured to form the outermost coating layer, and then the outermost coating layer and the inner coating layer are superposed on the molding surface, and this is irradiated with an electron beam to cure and bond to obtain It is a method of peeling the obtained sheet-shaped laminate from the molding surface.

The electron beam curable resin 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. Any coating method or the like may be used. Further, a fountain coater or a slit die coater can be used as a method for applying the resin composition. Especially when the surface of a metal drum is used as the molding surface, the roll coating method or the offset gravure coating method using a rubber roll is used to prevent scratches on the molding surface. Fountain coater and slit die coater are preferably used.

The electron beam accelerator used for 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 system, a double scanning system, a curtain beam system, or the like can be used. However, among these, the curtain beam system, which is relatively inexpensive and has a large output, is effectively used. The accelerating voltage at the time of electron beam irradiation is not limited, but generally 100 to 300 KV is preferable. The absorbed dose is preferably 0.1 to 6 Mrad, more preferably 0.2 to 4 Mrad.

The oxygen concentration in the atmosphere during electron beam irradiation is preferably 500 ppm or less. When the oxygen concentration exceeds 500 ppm, oxygen acts as a retarder for the polymerization reaction, and the curing of the electron beam curable resin may be insufficient. When the electron beam curable resin coating liquid layer is cast by a polyester film or a metal drum and cured by electron beam irradiation, the electron beam curable resin coating liquid layer directly contacts the air during electron beam irradiation. Without
Therefore, it is not necessary to particularly reduce the oxygen concentration in the atmosphere during electron beam irradiation, but nitrogen gas is used 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 an inert gas such as argon gas.

The film-forming synthetic resin used for forming the backside resin coating layer of the present invention may have a water vapor permeability of [80 g / m ² · 24 hours] (25 ° C., 90% RH) or less. The polyolefin resin used in the production of the conventional support for photographic printing paper, or the electron beam curable resin described above can be used.

As the polyolefin resin for forming the backside resin coating layer, homopolymers of ethylene, α-olefins such as propylene, at least two copolymers of the above-mentioned olefins, and various kinds of these polymers can be used. 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 antioxidant and 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.

The backside resin coating layer can also be formed of an electron beam curable resin. For this purpose, an electron beam curable unsaturated organic compound having low moisture permeability used for forming the surface resin coating layer can be used. Further, the method for forming the backside resin coating layer may be a multilayer structure as in the case of the above-mentioned frontside resin coating layer. The coating amount 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 .

As the paper substrate used in the present invention, one having a basis weight of 50 to 300 g / m ² and a smooth surface is usually used. The paper substrate can be selected from all 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.

When a photographic printing paper is produced from the support of the present invention, the magnesium hydroxide, magnesium oxide and magnesium salt described in JP-A-4-234754 are used for the purpose of preventing fog which occurs during long-term storage. It is effective to include a magnesium compound such as Further, the paper substrate may be blended with additives such as a sizing agent, a fixing agent, a paper strengthening agent, a filler, an antistatic agent, a pH adjusting agent, a pigment and a dye which are generally used for papermaking. In addition, surface sizing agent, surface paper strength agent, pigment,
A dye, an antistatic agent, or the like may be appropriately applied by a size press or the like.

[0043]

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 to these embodiments.

Example 1 A paper substrate 1 (for moisture permeability measurement) having a basis weight of 180 g / m ² and a back surface of this paper substrate were subjected to a surface activation treatment by corona discharge, and a low density polyethylene (having a density of 0). .918 g
/ Cm 3, 50 parts by weight of melt index 4 g / 10 minutes and high density polyethylene (density 0.964 g / cm 3,
Melt index 20 g / 10 min) Paper base 2 on which a backside resin coating layer having a coating amount of 25 g / m ² is formed by melt extrusion coating of a polyethylene resin mixed with 50 parts by weight.
(For evaluation of surface property and flexibility), 20 ° C, 65
The humidity was adjusted to% RH.

Separately, an electron beam curable resin of the electron beam curable unsaturated organic compound-white pigment mixture composition (composition (1)) for the surface resin coating layer having the following composition was prepared. Composition (1) Component Content Amount of nonylphenol EO modified acrylate 25 parts by weight (Trademark: Aronix M111, manufactured by Toagosei Kagaku, formula (8)) 25 parts by weight of polyester acrylate (Trademark: Aronix M7100, manufactured by Toa Gosei Chemical) Titanium dioxide 50 parts by weight (trademark: Taipaque A-220, manufactured by Ishihara Sangyo)

The composition (1) was mixed and dispersed with a paint conditioner for 1 hour, and then the composition (1) was added to
On the surface of the paper substrate 1 and on the surface of the paper substrate 1, a wire bar was used to apply a coating amount of 30 g / m ² after curing, and this was laminated with a polyester film used as a molding surface. Acceleration voltage: 175KV, absorbed dose: 2Mra from the back of the polyester film to the coating liquid layer
After irradiating the coating liquid layer with an electron beam under the condition of d, the polyester film was peeled off to prepare a sample for moisture permeability measurement and a sample for evaluating surface property and flexibility.

In order to evaluate the water vapor transmission rate of the support for photographic printing paper, at 25 ° C. according to JIS Z 0208 (1976 version) “Moisture transmission test method for moisture-proof packaging materials (cup method)”.
The moisture permeability was measured using the moisture permeability measurement sample obtained from the paper substrate 1 under the condition of 90% RH, and the moisture permeability of the surface resin coating layer was calculated by the following mathematical formula (1).

1 / (moisture permeability of surface resin coating layer) = 1 / (moisture permeability of sample for moisture permeability measurement) -1 / (moisture permeability of paper substrate 1) (1)

The flexibility was evaluated by using the sample for evaluating the surface property and the flexibility obtained from the paper substrate 2 with the surface resin coating layer on the outside and winding the sample on a round bar having a diameter of 0.1 cm, and cracking. The condition was visually evaluated. Evaluation was made on a three-point scale, in which no crack was observed at all, 3 points were slightly cracked at 2 points, and cracked was 1 point. Three and two points are practical, but one point is not practical.

In order to evaluate the surface property of the support for photographic printing paper, the sample for evaluating the surface property and the flexibility obtained from the paper substrate 2 was used in accordance with JIS K 7105 "Optical property test method for plastics". 12 at 20 ℃ and 65% RH
The humidity was adjusted for time, and the image clarity was measured using a 2 mm comb.
After that, the humidity is controlled at 20 ° C and 85% RH for 6 hours.
The image sharpness was measured using a mm comb, and the rate of change in the image sharpness before and after humidity adjustment was calculated by the following mathematical formula (2).

(Change rate of image definition) = (image definition after humidity adjustment) / (image definition before humidity adjustment) (2)

If the rate of change in image clarity is 0.8 or more,
There is no problem in practical use, but if it is less than 0.8, deterioration of the surface property due to a change in environmental humidity becomes a problem.

Example 2 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (2) having the following composition was prepared and used instead of the composition (1), and the coating amount after curing was 2
Coating was performed so as to be 5 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (2) Component Content Amount of nonylphenol PO-modified acrylate 25 parts by weight (Trademark: Aronix M117, manufactured by Toagosei Kagaku Co., Ltd., a mixture of formulas (15) and (16)) Polyester acrylate 25 parts by weight (Trademark: Aronix M7100, Toa Synthetic chemistry) Titanium dioxide 50 parts by weight (Trademark A-220, manufactured by Ishihara Sangyo)

Example 3 A support for photographic printing paper was prepared in the same manner as in Example 1. However, a composition (3) having the following composition was prepared and used instead of the composition (1). Table 1 shows the evaluation results obtained in the same manner as in Example 1. Composition (3) Component Content Amount of phenol EO-modified acrylate 15 parts by weight (Trademark: Aronix M101, manufactured by Toagosei Kagaku, Formula (3)) 35 parts by weight of polyester acrylate (Trademark: Aronix M7100, manufactured by Toagosei Chemical) Titanium dioxide 50 parts by weight (trademark: Taipaque A-220, manufactured by Ishihara Sangyo)

Example 4 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (4) having the following composition was prepared and used in place of the composition (1), and the coating amount after curing was 2
It was applied so as to be 0 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (4) Composition Blend amount α-Dimethylbenzylphenol EO modified acrylate 35 parts by weight (Trademark: Aronix TO-1210, manufactured by Toa Gosei Kagaku, formula (30)) Polyester acrylate 15 parts by weight (Trademark: Aronix M7100, Toa Synthetic chemistry) Titanium dioxide 50 parts by weight (Trademark A-220, manufactured by Ishihara Sangyo)

Example 5 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (5) having the following composition was prepared and used instead of the composition (1), and the coating amount after curing was 1
Coating was performed so as to be 5 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (5) Component Compounding amount Nonylphenol EO modified acrylate 25 parts by weight (Trademark: Aronix M111, manufactured by Toagosei Kagaku, formula (8)) Polyester acrylate 25 parts by weight (Trademark: Aronix M8100, manufactured by Toagosei Chemical) Titanium dioxide 50 parts by weight (trademark: Taipaque, A-220, Ishihara Sangyo)

Example 6 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (6) having the following composition was prepared and used in place of the composition (1), and the coating amount after curing was 1
It was applied so as to be 0 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (6) Component Compounding amount 2-hydroxy-3-phenoxypropyl acrylate 25 parts by weight (Trademark: Aronix M5700, manufactured by Toagosei Kagaku, formula (26)) Polyester acrylate 25 parts by weight (Trademark: Aronix M7100, Toagosei) Chemical) Titanium dioxide 50 parts by weight (Trademark: Taipek A-220, Ishihara Sangyo)

Example 7 A support for photographic printing paper was prepared in the same manner as in Example 1. However, a composition (7) having the following composition was prepared and used instead of the composition (1), and the coating amount after curing was 2
It was applied so as to be 0 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (7) Component Ingredient amount Dicyclopentenyl acrylate 25 parts by weight (Trademark: FANCYL FA-511A, manufactured by Hitachi Chemical Co., Ltd., mixture of formula (32) and formula (33)) Polyester acrylate 25 parts by weight (Trademark: Aronix M7100, manufactured by Toagosei Kagaku) 50 parts by weight of titanium dioxide (Trademark A-220, manufactured by Ishihara Sangyo)

Example 8 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (8) having the following composition was prepared and used in place of the composition (1), and the coating amount after curing was 2
It was applied so as to be 0 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (8) Component content Amount of tricyclodecanyl acrylate 20 parts by weight (trademark: FANCRYL FA-513A, manufactured by Hitachi Chemical Co., Ltd., formula (36)) 30 parts by weight of polyester acrylate (trademark: Aronix M7100, manufactured by Toagosei Kagaku) ) Titanium dioxide 50 parts by weight (Trademark: Taipek A-220, manufactured by Ishihara Sangyo)

Example 9 A support for photographic printing paper was prepared in the same manner as in Example 1. However, a composition (9) having the following composition was prepared and used instead of the composition (1), and the coating amount after curing was 2
It was applied so as to be 0 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (9) Component content Amount of isovonyl acrylate 30 parts by weight (Trademark: New Frontier IBA, manufactured by Dai-ichi Kogyo Seiyaku, formula (37)) 20 parts by weight of polyester acrylate (Trademark: Aronix M7100, manufactured by Toagosei Kagaku) Dioxide Titanium 50 parts by weight (Trademark A-220, manufactured by Ishihara Sangyo)

Example 10 In order to obtain a surface resin coating layer having a laminated structure, the following composition (10) was prepared separately. Composition (10) Component Blending amount 6EO Trimethylolpropane triacrylate 70 parts by weight (Trademark: Aronix M-360, manufactured by Toagosei) Titanium dioxide 30 parts by weight (Trademark A-220, manufactured by Ishihara Sangyo)

The above composition (10) was mixed and dispersed for 1 hour with a paint conditioner to prepare an electron beam curable resin.

First, the composition (10) was applied on the surface of a polyester film used as a molding surface using a wire bar so that the coating amount after curing would be 8 g / m ² , and this coating liquid layer Was irradiated with an electron beam at an accelerating voltage of 175 KV and an absorbed dose of 2 Mrad to cure the coating liquid layer.

Separately, the composition (1) was applied onto the surface of the paper substrate 1 and the surface of the paper substrate 2 using a wire bar so that the coating amount after curing was 25 g / m ^2. Then, this coating liquid layer was superposed on the above-mentioned cured coating layer on the polyester film surface, and the acceleration voltage: 175 KV, absorbed dose:
The multilayer body was cured and adhered by irradiating it with an electron beam under the condition of 2 Mrad, and then the multilayer body obtained in this step was peeled from the polyester film to prepare a support for photographic printing paper. Table 1 shows the evaluation results obtained in the same manner as in Example 1.

Comparative Example 1 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (11) having the following composition was prepared and used instead of the composition (1). Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (11) Component Blend Acrylic monophorine 20 parts by weight (Trademark: ACMO, manufactured by Kojin) Polyester acrylate 30 parts by weight (Trademark: Aronix M7100, manufactured by Toagosei Kagaku) Titanium dioxide 50 parts by weight (Tradek A) -220, made by Ishihara Sangyo)

Comparative Example 2 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (12) having the following composition was prepared, and this was used instead of the composition (1), and the composition was applied so that the coating amount after curing was 8 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (12) Component content Amount of nonylphenol EO modified acrylate 49 parts by weight (Trademark: Aronix M111, manufactured by Toagosei Kagaku, formula (8)) Polyester acrylate 21 parts by weight (Trademark: Aronix M7100, manufactured by Toa Gosei Chemical) Titanium dioxide 30 parts by weight (Trademark: Taipek A-220, made by Ishihara Sangyo)

Comparative Example 3 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (13) having the following composition was prepared, and the composition (1) was used instead of the composition (1) so that the coating amount after curing was 20 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (13) Composition Blend amount Nonylphenol PO-modified acrylate 12 parts by weight (Trademark: Aronix M117, manufactured by Toa Gosei Kagaku Co., Ltd., mixture of formulas (15) and (16)) Polyester acrylate 68 parts by weight (Trademark: Aronix M7100, Toa Synthetic chemistry) Titanium dioxide 20 parts by weight (Trademark: Taipek A-220, Ishihara Sangyo)

Comparative Example 4 A photographic printing paper support was prepared in the same manner as in Example 1. However, a composition (14) having the following composition was prepared, and this was used instead of the composition (1) and applied so that the coating amount after curing was 20 g / m ² . Table 1 shows the evaluation results obtained by evaluation in the same manner as in Example 1. Composition (14) Composition Blend amount Phenol EO modified acrylate 42.5 parts by weight (Trademark: Aronix M101, manufactured by Toagosei Kagaku, formula (3)) Polyester acrylate 7.5 parts by weight (Trademark: Aronix M7100, Toagosei Kagaku) Made) Titanium dioxide 50 parts by weight (Trademark: Taipek A-220, made by Ishihara Sangyo)

[0069]

[Table 1]

Moisture permeability, flexibility in Examples and Comparative Examples,
Table 1 shows the measurement results of surface gloss.

It can be seen that the moisture permeability and the flexibility are changed depending on the compounding amount of the electron beam curable resin of the formula (1). In addition, the surface gloss is water vapor permeability of 80 [g / m ² · 24 hours] (2
5 ° C., 90% RH) or less, the rate of change in image clarity, which represents the change in surface gloss, is 0.8 or more, and there is little change in the surface state due to changes in the humidity of the atmosphere, and there is flexibility. A support for photographic paper is obtained.

[0072]

The photographic printing paper support of the present invention is an electron beam curable resin against a decrease in surface gloss due to environmental changes, especially humidity changes, which is a general drawback when an electron beam curable resin coating layer is provided. Maintains the surface properties of the coating layer and excels in image sharpness,
In addition, it is flexible and therefore extremely useful in practice.

Claims (3)

[Claims] 1. A cured product of a paper substrate containing natural pulp as a main component, and a composition containing an unsaturated organic compound which is formed on one surface of the paper substrate and can be cured by electron beam irradiation as a main component. And 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, according to JIS Z 0208 of the surface resin coating layer. Water vapor transmission rate based on 80 [g / m ² · 24 hours] (measurement conditions: 25 ° C, 90
% RH) or less, a photographic paper support. 2. The surface resin coating layer has the following formula (1): [Wherein, in the formula (1), R ₁ represents a phenyl group or a phenyl group having a substituent, a dicyclopentenyl group or a dicyclopentenyl group having a substituent, a tricyclodecanyl group or a tricyclodeca group having a substituent] R ₂ represents an nyl group, an isobornyl group or an isobonyl group having a substituent, R ₂
Is an alkylene ether group or an alkylene ether group having a hydroxyl group. ] The unsaturated organic compound represented by the formula and curable by electron beam irradiation has a weight ratio of the unsaturated organic compound of the formula (1) to the unsaturated organic compound other than the formula (1) of 20/80 to 80/20. The support for photographic printing paper according to claim 1, wherein the support is formed of an electron beam cured product of a mixture contained so that the surface resin coating layer has a coating amount of 10 to 40 g / m ² . 3. The surface resin coating layer has a laminated structure of two or more layers including at least an inner resin coating layer adjacent to the paper substrate and an outermost resin coating layer arranged on the outermost side, A support for photographic printing paper, wherein at least one of the resin coating layers comprises the electron beam cured product according to claim 1 or 2.