JPH01284850A - Photographic supporting body and its production - Google Patents

Abstract

PURPOSE:To obtain the surface of the title body with high luster by applying an electron beam curing composition on the surface of a supporting body, and then smoothening the coated surface of the supporting body with a smoothening bar vibrating the bar in the direction of the width of the supporting body while rotating the bar, following by curing the composition. CONSTITUTION:The supporting body 1 of a raw material 1 is sent to a coater 3 from a take-out roll 2, and the electron beam curing composition 4 composed of the electron beam curing resin and a white pigment is applied on the supporting body 1. The supporting body 1 applied the composition 4 thereon is smoothened with the smoothening bar 5 while rotating the bar in the direction of the take-up or the take-out of a roll, and then an opaque resin coated layer is formed by curing the composition 4 by irradiating the composition with an electron beam by mean of an electron beam irradiating device 6, and by winding the obtd. composition around the take-up roll 7. Thus, as the obtd. photographic supporting body is smoothened the surface of an applied electron beam curing composition layer, the luster of the cured photographic supporting body does not have antisotropy, and the photographic supporting body with a high luster surface is obtd.

Description

[Detailed description of the invention] (A) Industrial application field The present invention relates to a support for photographic paper.

More specifically, the present invention relates to a water-resistant photographic support in which the support is provided with an opaque resin coating layer comprising an electron beam curable resin and a white pigment.

CB) Prior Art In recent years, waterproof paper in which a polyolefin resin layer into which a white pigment has been kneaded is provided on the surface of a base paper serving as a support has been mainly used as a photographic support. The main reason for providing a polyolefin resin layer on the base paper in this way is to prevent processing chemicals from penetrating into the base paper during development.This coating layer makes it possible to shorten the development time, and also Since there is no processed material left inside, yellowing due to aging can be avoided. Coating of base paper with such polyolefin resin is generally carried out using a melt extruder. Furthermore, inorganic white pigments such as titanium dioxide are mixed into the polyolefin resin layer on the surface of the photographic paper to improve the hiding power and whiteness of the photographic support and to improve the resolution of the photographic paper. It's included.

[C] Problems to be Solved by the Invention However, polyolefin resins have extremely high viscosity even when melted, making it difficult to disperse inorganic pigments such as titanium dioxide, and the types of polyolefin resins that can be used are limited. Ta. In addition, there is a limit to the filling rate of inorganic pigments, and in order to obtain a certain degree of hiding power and whiteness, it is necessary to increase the thickness of the resin layer. Since this is done at a temperature higher than the thermal decomposition temperature of the polyolefin resin, yellowing and pinholes occur in the resin layer due to the thermal decomposition of the resin. moreover,
When the extrusion speed increases, the adhesiveness with the base paper decreases, causing a problem in that the quality of the final product deteriorates.

In the production of resin-coated photographic supports, melt extrusion allows the thinning of opaque resin coating layers while maintaining adequate hiding power, and the ability to increase coating speed without degrading quality. Because it is difficult to do so, we coat base paper for photographic paper with an electron beam curable resin (hereinafter referred to as an electron beam curable composition) kneaded with a white pigment, and then irradiate it with an electron beam. A method has been proposed for producing a water-resistant photographic support by forming an opaque grease-resistant Trim layer (
For example, Japanese Patent Publication No. 60-17104). In this method, a coating liquid in which a white pigment is dispersed at a high concentration in a resin such as acrylate ester that has unsaturated bonds that can be polymerized by electron beam irradiation is applied onto the base paper for photographic paper, and then polymerized by electron beam irradiation at room temperature. Since this method involves crosslinking and forming an opaque resin coating layer on the surface of the base paper, it is possible to thin the opaque resin coating layer without reducing the hiding power, and it also eliminates the yellowing of the resin caused by the melt extrusion method and pinholes. It becomes possible to produce a water-resistant photographic support without causing deterioration in the quality of the final product due to generation of molding, poor adhesion of resin layers, blocking, or matte finish.

However, in the continuous production of photographic supports using electron beam curable compositions, especially photographic supports in which an opaque resin coating layer highly filled with white pigment is coated at high speed and cured by electron beam irradiation. , there is a clear difference in gloss in the winding direction and width direction, and this is clearly noticeable as an unpleasant flicker even after the photographic paper is made with an emulsion layer on the photographic support. It became clear that it had a fatal spacing as a photographic paper. Furthermore, when a color emulsion layer is provided on a photographic support prepared by such a method, the color layer (generally a yellow layer) in contact with the opaque resin coating layer becomes disordered.

There was a problem in that, after development, periodic areas with poor color development (so-called blue spots) were generated.

CD) Means for Solving the Problems As a result of intensive research into means for solving the above-mentioned problems, the inventors have found the following solution. That is, in a photographic support, after an electron beam curable composition consisting of an electron beam curable resin and a white pigment is continuously applied to the surface of the support, the support is rotated in a direction opposite to the winding direction of the support. , and the applied electron beam curable composition is physically treated using a smoothing bar that vibrates in the width direction, and then the electron beam curable composition is cured by electron beam irradiation. It is an invention of a method.

In the present invention, even in a photographic support highly filled with a white pigment, there is no significant difference in gloss between the winding direction and the width direction, and it is possible to obtain a uniform and high-gloss photographic support. Furthermore, according to the present invention, surprisingly, after coating an electron beam curable composition, an emulsion layer was provided on a photographic support prepared using a smoothing bar vibrating in the width direction, thereby producing a photographic paper. It has become clear that high-quality photographic paper with extremely few occurrences of defective coloring areas can be obtained even in the above cases.

Hereinafter, the present invention will be explained in detail using figures.

In FIG. 1, a support 1 serving as a raw material is an unwinding roll 2.
It is sent to a die coater 3 and is coated with an electron beam curable composition 4. The support coated with the electron beam curable composition is smoothed by a smoothing par 5 that vibrates in the width direction while rotating in the winding direction or the opposite direction, and is irradiated with an electron beam by an electron beam irradiation device 6 to be cured with an electron beam. The composition is cured to form an opaque national resin coating layer, which is then wound up by a winding roll 7. Note that the surface of the support may be subjected to corona treatment using corona treatment FIi8, if necessary.

The electron beam curable resin used in the present invention is selected in consideration of conditions such as electron beam curable properties, high concentration dispersibility of white raw materials, weather resistance, film strength, heat resistance, curling properties, and adhesion to the support. You can choose.

Examples of electron beam curable resins include unsaturated polyesters having electron beam reactive groups at the molecular ends or side chains, modified unsaturated polyesters, acrylic polymers, and monomers having unsaturated bonds, alone or in combination with other Can be used with solvents. Representative examples of electron beam polymerizable resins are shown below.

(a) Polyester acrylate, polyester methacrylate.

Aronix M-5300, Aronix M
-5400,7D Nix M -5500.

Aronix M-5600, Aronix M-5700
, Aronix M-6100, Aronix M-620
0, Aronix M-6300, Aronix M-6
500, Aronix M-7100, Aronix M8
030, Aronix M-8060, Aronix M
-8100 (Toagosei Chemical Industry Co., Ltd. product name),
Viscoe Door 00, Viscoe 3700 (trade names of Osaka Organic Chemical Industry 6 Co., Ltd.), Kayarad HX-220
, Kayarad HX-620 (all trade names of Nippon Kayaku Co., Ltd.), and the like.

(b) Urethane acrylate, urethane methacrylate, e.g. Aronix M-1100, Aronix M-
1200, Aronix M-1210, Aronix M
-1250, Aronix M-1260, Aronix M-1300, Aronix M-1310 (trade names manufactured by Toagosei Chemical Industry Co., Ltd.), Viscoat 812, Viscoat 823, Viscoat 823 (trade names manufactured by Osaka Organic Chemical Industry Co., Ltd.) name), NK ester, U-108-A,
Examples of N' include ester and U-4HA (all trade names of Shin-Nakamura Chemical Co., Ltd.).

(C) Monofunctional acrylate, monofunctional methacrylate, vinylpyrrolidone, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate,
Cyclohexyl methacrylate-1, acryloylmorpholine, benzyl acrylate-1, glycidyl methacrylate-1, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl methacrylate, N,
N-diethylaminoethyl methacrylate, butoxyethyl acrylate, vinylpyrrolidone, etc., ethylene oxide-modified phenoxylated phosphoric acid acrylate, ethylene oxide-modified butoxylated phosphoric acid acrylate, and other products such as Aronix M by Toagosei Chemical Industry Co., Ltd.
-101, Aronix M-102, Aronix M-
111, Aronix M113, Aronix M-11
4-Aronix M-117, Aronix M-152
, Aronix M-154, etc.

(d) polyfunctional acrylate, polyfunctional methacrylate, for example 1,6-hexanediol diacrylate,
1,6-hexanediol diacrylate, neopentyl glycol diacrylate-1-1 diethylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, pentaerythritol diacrylate, dipenta Erythritol hexaacrylate, isocyanuric acid diacrylate, pentaerythritol triacrylate, isocyanuric acid triacrylate triacrylate, trimethylolpropane trimethacrylate, ethylene oxide modified pentaerythritol tetraacrylate, propylene oxide modified pentaerythritol tetraacrylate, propylene oxide modified Examples include dipentaerythritol polyacrylate, ethylene oxide-modified dipentaerythritol polyacrylate, and acrylate ester of pentaerythritol acrylic acid adduct. The product names of Toagosei Chemical Industry Co., Ltd. are Aronix M-210, Aronix M-215, Aronix M-220, Aronix M-230, Aronix M-233, Aronix M-240, Aronix M-245, Aronix M.
-305, Aronix M-309, Aronix M310, Aronix M315-Aronix M
-320, Aronix M-325, Aronix M-
330, Aronix M-4 00, Aronix M
-450, To-458, To-747, TO-75
5-THIC. Examples include TA2.

Examples of the white pigment in the electron beam curable composition used in the present invention include rutile-type or anatase-type titanium dioxide, zinc oxide, talc, calcium carbonate, barium carbonate, barium sulfate, calcium citrate, and silica. It can be used untreated or after surface treatment with siloxane, alumina, alcohol, etc. The proportion of white pigment in the electron beam curable composition is 20 yen L amount%
It is preferable that the range is from 20% to 70% by weight, and particularly preferably from 20% to 70% by weight. This means that if the ratio of white pigment is extremely small, it will not have the expected hiding power, and if it is too large at the RI1 end, not only will the binder ability of the electron beam curable resin be insufficient, but also the amount of electron beam irradiation will be insufficient. This is because it causes an increase in the amount of oil and has an unfavorable effect on the base paper for photographic stamp paper or the coated coating that has been formed.

The electron beam curable composition of the present invention contains pigments and dyes such as ultramarine and cobalt violet, which are used in the surface polyethylene layer of photographic supports prepared by conventional polyolefin resin melt extrusion methods, and antioxidants. agent,
Various additives such as optical brighteners, antistatic agents, dispersants, and stabilizers can be added in appropriate combinations.

In the present invention, since the electron beam curable resin is cured by electron beam irradiation, a reaction initiator is not required in principle, but a photoinitiator may be mixed in for the purpose of reducing unreacted resin. Photoinitiators include acetophenones such as di- and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyl dimethyl ketal,
There are tetramethylthiuram monosulfide, thioxanthone, azo compounds, various silver salts, etc., and the amount of photoreaction initiator used is usually 0.1 to 10% based on the electron beam curable resin.
% range. Further, a storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

As the support used in the present invention, ordinary natural pulp paper, synthetic fibers, so-called synthetic paper made of synthetic resin film, plastic film, metal foil, or laminates thereof can be used.
Natural pulp paper whose main component is wood valves such as softwood bulbs, hardwood bulbs, and mixed softwood and hardwood bulbs, and laminated paper made by laminating the surface of natural pulp paper with molten polyolefin resin are advantageously used. There is no particular restriction on the thickness of the support, and its basis weight is 50 g/rn"
~250 g/rn'' is preferred.

The base paper support mainly composed of natural bulbs, which is advantageously used in the method of the present invention, can contain various molecularly enriched metals and additives. For example, starch derivatives, polyacrylamide, polyvinyl alcohol derivatives,
Dry paper strength enhancers such as gelatin, sizing agents such as fatty acid salts, rosin derivatives, dialkyl ketene dimer emulsions, wet paper strength enhancers such as melamine resins, urea resins, and epoxidized polyamides, stabilizers, pigments, dyes, oxidation An inhibitor, a fluorescent whitening agent, various latexes, an inorganic electrolyte, p)(p)(p)(p)(p)(p), u?f, etc. can be contained in an appropriate combination.

Furthermore, in the present invention, even if the surface of the support is subjected to surface treatment such as corona treatment in order to improve the adhesion and wettability between the support and the opaque resin coating layer, the electron beam curable composition and the photosensitive emulsion may In order to improve adhesion and wettability, the surface of the cured oil layer may be subjected to surface treatment such as corona treatment or sub-coating.

Further, on the back side of the photographic support of the present invention, a film can be formed by coating a polyolefin resin by the conventional melt extrusion method or by applying an electron beam curable resin and then irradiating it with an electron beam. Form a resin coating layer by the method of
In addition, a back coat layer may be provided to provide writing properties on the back side.

A general raw material kneader can be used to prepare the electron beam curable composition. For example, two-roll, three-roll, ball mill, niegu, high-speed mixer,
Homogenizer etc.

The method for applying the electron beam curable composition onto base paper is as follows:
For example, methods such as blade coating, doctor coating, air knife coating, spray coating, squeeze coating, reverse roll coating, gravure roll and transfer roll coating, extrusion coating, and curtain coating are used.

The material of the smoothing bar used in the present invention may be metal, ceramic, or hard plastic.
The number of smoothing bars used can be one or more.It is desirable that the surface of the smoothing bar be mirror-like, but if multiple smoothing bars are used, there may be a mesh on the surface of the smoothing bar on the coater side. The rotational speed of the bar is 17% relative to the advancing speed of the support.
A speed of 3 to 5 times is appropriate; if the rotation speed of the smoothing bar is lower than this range, the ability to smooth the electron beam curable composition coated on the support will not be sufficient and the gloss will decrease. If it is larger than this range, the cause is unknown, but diagonal streaks occur and are very unsightly.When using multiple smoothing bars, please note that the rotation speed, bar radius, surface condition, and bar material should be The vibration of the smoothing bar is performed to dramatically improve the surface properties of the electron beam curing paper layer, and by performing this vibration, the smoothing bar can be changed individually. The adhesive composition 1 can perform smoothing not only in a certain traveling direction but also in the width direction, and can obtain an extremely uniform smooth surface. When using a plurality of smoothing bars, it is preferable to vary the vibration period of each smoothing bar from the viewpoint of long-term production stability.

Furthermore, the smoothing bar may be attached at right angles to the direction in which the support moves, or at a certain angle.

The polyolefin resin used in the back or brimer layer or the outermost surface may be a homopolymer of olefins such as polyethylene, polypropylene, polybutene, or polypentene, or a copolymer of two or more olefins such as ethylene/propylene copolymer. and mixtures thereof, among which polyethylene is particularly advantageously used.

The thickness of the opaque resin coating layer made of the electron beam polymerizable composition varies depending on the type of support and the filling rate of the white pigment.
2 to 100 μm, more preferably 3 to 50 μm,
Whiteness is thinner than this thickness.

It is difficult to obtain a sufficient opacity from the viewpoint of opacity, and it is difficult to apply the coating uniformly.If the thickness is thicker than this, it is difficult to provide a uniform coating layer, which is not desirable in terms of quality. If the surface is to be further given a mirror finish or a molded finish, the surface to be treated can be brought into contact with a mirror roll or a molded roll and cured by irradiating an electron beam from the back side to give the surface a mirror finish. Alternatively, there is a method in which the surface is partially cured by irradiating with 1,000 mK particle beams in advance, and then brought into contact with a mirror roll or molding roll and subjected to secondary irradiation to completely cure the surface.

For electron beam irradiation, the acceleration voltage is 10 from the viewpoint of penetrating power and curing power.
0 to 1000 kV, more preferably 100 to 30
It is preferable to use a 0 kV electron beam accelerator so that the absorbed dose in one bath is 5 to 20 Mrad. If the accelerating voltage or electron beam irradiation amount is lower than this range, the penetrating power of the electron beam will be too low. If sufficient curing is not carried out and the amount exceeds this range, not only will energy efficiency deteriorate, but also unfavorable effects will appear in terms of quality, such as a decrease in the strength of the base paper and decomposition of the resin and additives. The electron beam accelerator may be, for example, an electrocurtain system, a scanning type, a double scanning type, or the like.

In addition, during electron beam irradiation, if the oxygen concentration is high, curing of the electron beam curing resin will be hindered, so replacement with an inert gas such as nitrogen, helium, carbon dioxide, etc. is performed to reduce the oxygen concentration to 6.
It is preferable to irradiate in an atmosphere stamped with a concentration of 00 ppm or less, preferably 400 ppm or less.

In addition, on the opaque fat-absorbing coating layer of the photographic support prepared according to the present invention, smoothness, water resistance, element resistance, easy cleaning, and adhesion with the photosensitive emulsion on the outermost surface of the photographic support are added. sex,
A coating layer made of polyolefin resin may also be provided to impart properties such as antifogging properties to the photosensitive emulsion.

Further, a brimer layer may be provided between the paper support and the opaque resin coating layer to even out the unevenness of the paper support.

A photographic support prepared according to the present invention can be used as a photographic paper by coating a photosensitive emulsion thereon.

[20 Effects] In the photographic support produced in the present invention, the surface of the electron beam curable composition layer coated on the support is made extremely smooth by the action of the smoothing bar that rotates and vibrates in the width direction. Therefore, a photographic support having no anisotropy in gloss after curing by electron beam irradiation and having a high gloss surface can be obtained. The photographic paper produced using the photographic support obtained by this method has no anisotropy in gloss, has high gloss, and has a good appearance.Furthermore, because the photographic support has good flatness, it cannot be used with conventional electron beams. There is no problem of blue spots that frequently occur in photographic paper made from photographic supports using a curable composition coating method.

CF) Examples ” The present invention will be described in detail below with reference to Examples, but the content of the present invention is not limited to the Examples.

Example-1 Low density polyethylene (density 0.918g/
cm3, MI5) slaughter density polyethylene (density 0
．． 965 g/am3, laminate coated with an average thickness of 18 μm with a mixture of M I 7 )-, basis weight 1
After applying corona treatment to the surface using 20 g/ba photographic base paper as a support, an electron beam curable composition having the following composition was coated with an average thickness of 5 μm while unwinding at a winding speed of 50 m/min.
It was applied so that the thickness was m.

(Electron beam curable composition) Rutile titanium dioxide 34% by weight Electron beam curable resin 70% by weight Leveling agent
The 1% by weight electron beam curable resin and the rutile titanium dioxide were mixed using a three-roller.

Trimethylolpropane triacrylate was used as the electron beam curable resin.

The leveling agent used had a perfluoroalkyl group.

The support coated with the electron beam curable composition obtained in this way was attached with four metal smoothing bars of 5 cm in diameter in parallel, and moved 80 m/min in the opposite direction to the traveling direction of the support.
The three smoothing bars on the coater side are vibrated at 4 Hz with different periods.
The electron beam irradiation device was passed through a smoothing zone having a structure in which one smoothing bar was fixed on the side of the electron beam irradiation device.
(manufactured by ESI, Electro Curtain).

Acceleration voltage 1 '75 kV, absorption line fL2 M r a
Electron beam irradiation was performed under the conditions of d to cure the electron beam curable composition layer and obtain a photographic support.

Example 2 A photographic support was prepared using the same support and electron beam curable composition layer as in Example 1, but with the structure of the smoothing zone changed as follows. In other words, the rotation speed of the smoothing bar is set to 50 m/min and 60 m/min for the bar closer to the coater.
m/min, and 80 m/min, and the vibration frequency was set to the same frequency as 6 Hz, and one smoothing bar on the electron beam irradiation device side was fixed and passed through a smoothing zone having a structure that rotates at 80 m/min. A photographic support was obtained in the same manner as in Example-1 except for the other constitution.

Comparative Example-1 A photographic support was obtained in the same manner as in Example-1 except that the same support and electron beam curable composition layer as in Example-1 were used, and the smoothing zone was not used. .

Comparative Example 2 Using the same support and electron beam curable composition layer as in Example 1, a photographic support was prepared by changing the structure of the smoothing zone as follows. That is, the rotational speed of all four smoothing bars was set to 80 m/min, the four smoothing bars were rotated without vibration, passed through a support coated with an electron beam curable composition, and irradiated with an electron beam to form a photographic support. I got it.

The photographic supports obtained in Examples and Comparative Examples were
A portion of the sample was sampled as a photographic support, then subjected to corona treatment, coated with a color silver halide photographic emulsion in the usual manner, hardened to form a photographic paper, and then subjected to a series of development treatments for evaluation. did.

In the gloss anisotropy test, the 60 degree gloss was measured by changing the angle of the sample using a variable angle gloss needle VSG-1001DP manufactured by Nippon Seishoku Kogyo Co., Ltd., and the variation thereof was measured. Blue edges on photographic paper were observed with the naked eye using a magnifying glass.
Table 1 summarizes the results regarding the adhesiveness and whiteness of the photographic supports prepared in Examples and Comparative Examples.

Table 1 [G] Effect of the Invention As is clear from Table 1, the photographic support produced in the present invention has an extremely smooth surface of the electron beam curable composition layer coated on the support. In addition, a photographic support having no anisotropy in gloss after curing by electron beam irradiation and a high gloss surface is obtained, and the gloss remains anisotropic even after being processed into photographic paper. It is possible to create high-quality photographic paper with a high gloss and good appearance.

Furthermore, since the photographic support has good flatness, it is possible to create a photographic stamp paper that does not have the trouble of blue edges that frequently occur in photographic paper made from a photographic support using the conventional electron beam curable composition coating method. I can do it.

[Brief explanation of the drawing]

FIG. 1 shows a manufacturing apparatus for manufacturing the photographic support of the present invention. 1... Support body, 2... Unwinding roll, 3...
- Coater, 4... Electron beam curable composition, 5...
・Smoothing bar, 6...Electron beam irradiation device. 7... Winding roll, 8... Corona discharge treatment machine.

Claims (3)

[Claims] (1) In a method for manufacturing a photographic support, after continuously applying an electron beam curable composition consisting of an electron beam curable resin and a white pigment to the surface of the support, the film is coated in the same direction as the winding direction of the support. Alternatively, the applied electron beam curable composition layer is treated using a smoothing bar that rotates in the opposite direction and vibrates in the width direction, and then the electron beam curable composition is cured by electron beam irradiation. A method for producing a photographic support. (2) In a photographic support, after continuously coating the surface of the support with an electron beam curable composition consisting of an electron beam curable resin and a white pigment, the support is wound in the same direction or in the opposite direction. Treating the applied electron beam curable composition layer using a smoothing bar that rotates and vibrates in the width direction,
A photographic support in which an electron beam curable composition is then cured by electron beam irradiation. (3) After continuously applying an electron beam curable composition consisting of an electron beam curable resin and a white pigment to the surface of the support, the support is rotated in the same direction or in the opposite direction to the winding direction, and A photographic print made using a photographic support in which the applied electron beam curable composition layer is treated using a smoothing bar that vibrates in the direction, and the electron beam curable composition is then cured by electron beam irradiation. paper.