JP2000241935A - Substrate for image material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high-speed stable production of a superior resin coated paper type substrate that gives an image material having high glossiness and its print and does not cause unevenness in peeling while remarkably suppressing the contamination of die lips. SOLUTION: At least one face of natural pulp-base paper as a base is coated with a thermoplastic resin-containing resin layer to obtain the objective substrate for an image material. The resin layer comprises at least two layers including bottom and top layers and at least the bottom and top layers are successively formed by melt extrusion coating. The melt flow rates of the bottom and top layers are >=9 each. Immediately after the formation of the bottom resin layer, rapid cooling and/or corona discharge treatment is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a paper comprising a natural pulp as a main component and a paper (hereinafter sometimes abbreviated as a base paper), at least one surface of which is covered with a resin layer containing a thermoplastic resin. And a method for producing a support for an image material. More specifically, a method for producing a support for an image material, in which the generation of die lip stains is remarkably suppressed during the production of the support, the releasability from the cooling roll is improved, and there is no occurrence of peeling unevenness, and high-speed and stable production is possible. Further, the present invention relates to an image material and a print thereof, particularly a silver halide photographic printing paper and a print thereof (a silver halide photographic printing paper), And a method for producing the same.

[0002]

2. Description of the Related Art Usually, an image material is composed of a support for an image material and an image forming layer provided on the support. For example, a silver halide photographic material, an ink-jet recording material, a heat transfer type thermal transfer recording image-receiving material, a heat-sensitive recording material, and a light- and heat-sensitive recording material are respectively provided on a support for an image material, a silver halide photographic component layer, an ink image-receiving layer, An image forming layer such as a transfer type thermal transfer recording image receiving layer, a thermosensitive coloring layer, a photosensitive thermosensitive coloring layer, and the like, and an undercoat layer, a protective layer and the like are provided as required. In particular, the silver halide photographic constituent layer includes a silver halide photographic emulsion layer, a protective layer, an undercoat layer, an intermediate layer or an anti-color-mixing layer, an antihalation layer, or a filter layer, an ultraviolet absorbing layer, and a combination thereof. It is composed of For example, a single silver halide photographic material has a silver halide photographic emulsion layer and a protective layer provided on a photographic material support. Further, a multilayer silver halide color photographic material comprises an undercoat layer, a blue-sensitive silver halide photographic emulsion layer and an intermediate layer, a green-sensitive silver halide photographic emulsion layer and an ultraviolet absorbing layer, A silver halide photographic emulsion layer and a silver halide color photographic constituting layer such as a protective layer are provided in this order and are arranged in multiple layers.

[0003] Conventionally, a resin-coated paper-type support in which a base paper surface for an image material support is coated with a thermoplastic resin is well known. Examples of a support for a photographic material for use in a silver halide photographic material include, for example, JP-B-55-1212.
No. 584 discloses a technique for a photographic material support in which a base paper is coated with a film-forming resin, preferably a polyolefin resin. U.S. Patent No. 3,
No. 501,298 discloses a technique for a photographic material support in which both surfaces of a base paper are coated with a polyolefin resin. Further, since the rapid photographic development processing method of silver halide photographic materials was applied, supports for photographic materials in which both sides of a base paper were coated with a polyethylene resin have been mainly put to practical use for photographic printing paper. If necessary, the resin layer on the side on which one of the image forming layers is provided usually contains a titanium dioxide pigment for imparting sharpness.

Further, US Pat. No. 4,774,224 discloses that
There has been proposed a thermal transfer recording image-receiving element having as a support a resin-coated paper having a resin coating having a surface roughness of 7.5 microinch-AA or less, particularly a polyethylene resin-coated paper in which the surface of a base paper is coated with a polyethylene resin. . JP-A-63-307979 discloses a technique relating to an ink jet recording sheet having a resin-coated paper as a support.

However, a resin-coated paper-type image material support in which the surface on which the image forming layer is provided of a base paper, especially a base paper mainly composed of natural pulp, is coated with a resin layer still has some serious problems. In fact, there are still many problems and satisfactory results have not yet been obtained.

The side on which the image forming layer of the base paper is provided (hereinafter, the side on which the image forming layer is provided is the front side, the resin layer coated on the front side is the front resin layer, the opposite side is the back side, and the resin layer coated on the back side is the back side. A resin-coated paper for use as a support for image materials, in which the surface of the backing resin layer is coated with a resin layer containing at least a film-forming resin, particularly a polyethylene-based resin, is usually coated on a running base paper. Using a melt extruder, a polyethylene resin composition is cast from a slit die into a film and coated, pressed between a pressure roll and a cooling roll, and separated from the roll after cooling. It is manufactured in the process. At that time, when manufacturing resin-coated paper for image materials for glossy use, as a cooling roll,
An extremely smooth smoothing roll having a mirror or glossy surface or a finely rough surface described in JP-B-62-19732 is used. In this way, the surface resin layer of the resin-coated paper is pressed into contact with a cooling roller having extremely good smoothness in the molten state, so that it is processed into a surface having good smoothness. Then, a material with a high glossiness should be obtained. However, in the case of an image material and a print thereof using a resin-coated paper actually produced as a support, it was not possible to obtain a material having a sufficiently high glossiness in appearance. In particular, in the case of a photographic printing paper using a resin-coated paper as a support, it was not possible to obtain a photographic printing paper and a photographic print having sufficiently high glossiness in appearance. Further, as the thickness of the surface resin layer of the resin-coated paper becomes thinner, particularly in the case of 31 μm or less, the apparent glossiness of the image material and the print of the image material using the resin-coated paper as a support becomes remarkable. It was found to be lower. In particular, photographic materials for glossy applications require a high degree of glossiness when printed on photographic prints, and photographic materials with inferior glossiness in photographic prints are completely unsuitable for glossy applications. There was a problem that the product had no commercial value.

Although resin-coated paper for image materials for glossy use is required to have a high degree of smoothness, in particular, when the thickness of the surface resin layer becomes thicker when extruding and coating a molten resin on a base paper, it becomes particularly difficult. In the case of 20 μm or more, or as the production speed of the resin-coated paper becomes faster, especially in the case of 260 m / min or more, the releasability of the resin-coated paper from the cooling roll is deteriorated, and the peeling unevenness on the surface of the resin-coated paper is reduced. This is called horizontal width-like unevenness in the width direction. When this peeling unevenness occurs, unevenness in gloss also occurs in an image material and a print using the resin-coated paper as a support, and there is a problem that the apparent glossiness is further reduced and the commercial value is significantly reduced.

Heretofore, there have been several technical proposals for eliminating and improving the above-mentioned problems and other disadvantages of the resin-coated paper type image material support. JP-A-59-198451
Craters which tend to form on the surface of the surface resin layer of a resin-coated paper-type photographic support by a two-layer extrusion coating method of a co-extrusion coating method and a sequential extrusion coating method disclosed in JP-A-1-303435 and the like. There is a description or an example of a technique for preventing and improving pores and providing a photographic support excellent in smoothness without surface defects, but is insufficient for solving the above-mentioned problems, and is particularly insufficient for resin coating. It was extremely insufficient to improve and improve the apparent glossiness of an image material having a paper support and its print.

Conventionally, the concentration of the titanium dioxide pigment in the resin coating layer is 9% by weight to 15% by weight,
Melt extrusion coated at a temperature of 40 ° C. When the addition amount of the titanium dioxide pigment is increased, streak-like dirt generated in the die lip portion of the extruder (hereinafter, sometimes abbreviated as dilip dirt) increases. If it exceeds, a streak is generated on the melt-extruded resin surface, and in severe cases, there is a problem that the resin surface may even break.

It is considered that the cause of the occurrence of the stain on the die lip is due to the partial accumulation of the melt in the die lip portion or the baking. However, when such stain on the die lip occurs, the image material produced by this is considered. A continuous streak appears in the longitudinal direction on the surface of the support. Such streaks caused by die lip stains not only significantly impair the appearance of the product, but are also a serious problem that makes it impossible to manufacture the product itself. In addition, there is no other way to completely remove the generated dilip stains except by disassembling and cleaning the die lip, and the disassembly and cleaning require a great deal of time and labor, resulting in a significant decrease in productivity. In fact, those skilled in the art are focusing on the solution.

Conventionally, various methods for preventing die lip contamination have been studied. For example, from the viewpoint of improving the resin composition,
A method using a combination of a specific amount of zinc oxide and a metal salt of a higher fatty acid (JP-A-53-102947), a method using a combination of a loss on drying of a titanium dioxide pigment and a specific amount of a metal salt of a fatty acid (Japanese Patent Laid-Open No. Sho 57-19757). JP-A-16819), a method of using a specific amount of an antioxidant and a specific amount of a fatty acid metal salt in combination (Japanese Patent Application Laid-Open No. 60-11841), conditions for drying loss of titanium dioxide pigment, fatty acid metal salt, composition melt viscosity and the like. There are proposals such as a method of selecting and using them in combination (Japanese Patent Publication No. 59-42296). Also,
A method of treating the surface of titanium dioxide with hydrous aluminum hydroxide from the viewpoint that the titanium dioxide needs to be modified because more dirt and grit occur as the titanium dioxide pigment used increases (JP-A-57-10849) Japanese Patent Application Laid-open No. Sho.
8-17433), a method of treating with an alkyl titanate (JP-A-57-151942), or a method of treating with an organoaluminum (JP-A-62-1415).
No. 44) or 0.3 weight loss on drying titanium dioxide.
5% or less (JP-A-59-1544, JP-A-59-121329, JP-A-59-2153)
No. 34) and a method of reducing the electric conductivity of a suspension of titanium dioxide to 60 mho / cm or less (JP-A-58-222014).
No. 0 gazette).

However, even these methods are not sufficient to prevent die lip contamination. In addition, as the amount of titanium dioxide pigment is increased in the resin layer or the speed of melt extrusion coating is increased, streaks are generated on the melt-extruded resin surface, and in severe cases, the resin surface even cracks. There is a problem that happens, usually
The content of the titanium dioxide pigment in the resin layer in the existing image material support is 15% by weight or less.

As a relatively recent technique for solving the above-mentioned problems, for example, JP-A-6-222499 discloses a technique in which a resin coating layer containing a polyolefin resin as a main component is formed on both surfaces of a sheet-like substrate. In the method for producing a photographic support, the resin layer on the side on which the emulsion of the support is coated is two layers, and the resin layer on the paper substrate side is an LDPE containing no additive.
Discloses a method for manufacturing a photographic support in which an upper layer and a lower layer are formed at a specific resin temperature (the upper layer is lower in temperature than the lower layer), and the thickness ratio of the two resin layers is specified.

Japanese Patent Application Laid-Open No. Hei 6-324431 discloses a photographic printing paper support provided with two or more water-resistant resin coating layers, wherein the upper and lower layers (the upper layer is lower in temperature than the lower layer) at a specific resin temperature. A photographic paper support is disclosed in which a layer is formed, a specific amount of titanium dioxide is contained in the upper layer, and the melt index of the water-resistant resin in the upper layer is higher than the melt index of the water-resistant resin in the lower layer.

Further, Japanese Patent Application Laid-Open No. 6-342194 discloses a photographic printing paper support provided with two or more water-resistant resin coating layers, in which an upper layer and a lower layer (the upper layer is lower in temperature than the lower layer) at a specific resin temperature. A layer is formed, a specific amount of titanium dioxide is contained in the upper layer, a specific inorganic pigment is contained in the lower layer, and the melt index of the water-resistant resin in the upper layer is higher than the melt index of the water-resistant resin in the lower layer. A paper support is disclosed.

[0016] However, even with these relatively recent technologies, the most recent technology orientation of 260 m / min or more,
In particular, 300 m / min or more, particularly 400 m / min or more, high speed melt extrusion coating, die lip stains, and peeling unevenness generated on the resin-coated paper surface due to deterioration of the releasability of the resin-coated paper from the cooling roll, and furthermore, the image It is not possible to produce a support for imaging materials which has a sufficiently high commercial value and sufficiently satisfies the unevenness of gloss and the apparent glossiness of materials and prints.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to provide a support for an image material in which a paper mainly composed of natural pulp is used as a substrate and at least one surface thereof is coated with a resin layer containing a thermoplastic resin. In the manufacturing method, the occurrence of die lip stains is remarkably suppressed, and the releasability from the cooling roll is improved so that there is no occurrence of peeling unevenness, and high-speed and stable production can be performed. Providing materials and photographic prints.

[0018]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is,

1. The present invention is a support for an image material in which a paper containing natural pulp as a main component is used as a substrate, and at least one surface thereof is coated with a resin layer containing a thermoplastic resin.
The resin layer is composed of at least two layers of a lowermost layer and an uppermost layer, and the resin layer is coated by a sequential extrusion coating method in which at least the lowermost layer and at least the uppermost layer are sequentially melt-extruded and coated. The invention is directed to a support for an image material, characterized in that:

2. In the above invention 1, in the resin layer composed of at least two layers, the resin layer composed of at least the uppermost layer is melt-extruded and coated at 170 ° C to 290 ° C, and the resin layer contains carbon dioxide. An invention of a support for an image material, wherein the support contains 15% by weight or more of a titanium pigment.

3. In the above invention 1 or 2, for the image material, wherein at least the lowermost resin layer of the at least two resin layers is melt-extruded and coated at 290 ° C to 340 ° C. It is an invention of a support.

4. In the above inventions 1 to 3, in the resin layer composed of at least two layers, the melt flow rate of the thermoplastic resin constituting each of the resin layers composed of at least the uppermost layer and the lowermost layer is 9 g / 10
Min. Or more.

5. In the above inventions 1 to 4, at least the resin layer consisting of the lowermost layer and the resin layer consisting of at least the uppermost layer are sequentially melt-extruded and coated, when coated by a sequential extrusion coating method, the preceding resin layer is The invention provides a support for an image material, characterized in that after being cooled by a rapid cooling device, the subsequent resin layer is melt-extruded and coated.

6. In the above invention 5, in the invention for the support for image materials, the subsequent resin layer is melt-extruded and coated within 10 seconds after the preceding resin layer is cooled by the rapid cooling device. is there.

[7] In the above inventions 1 to 6, the resin layer consisting of at least the lowermost layer and the resin layer consisting of at least the uppermost layer are sequentially melt-extruded and coated, and when coated by the sequential extrusion coating method, the preceding resin layer is The invention provides a support for an image material, wherein a subsequent resin layer is subjected to melt extrusion coating after being subjected to corona discharge treatment by a corona discharge treatment device.

8. In the above invention 7, after the preceding resin layer is subjected to corona discharge treatment by a corona discharge treatment device, the subsequent resin layer is melt-extruded and coated within 10 seconds. Invention.

9. The invention according to any one of the first to eighth inventions, wherein the running speed of the paper substrate is 260 m / min or more.

10. In the above invention 9, the invention is directed to an image material support, wherein the traveling speed of the paper substrate is 330 m / min or more.

(11) In the above invention 10, the invention is directed to an image material support, wherein the traveling speed of the paper substrate is 400 m / min or more.

12. The present invention is a method for producing a support for an image material, in which at least one surface thereof is coated with a resin layer containing a thermoplastic resin, using a paper mainly composed of natural pulp as a substrate, wherein the resin layer is a lowermost layer. And at least two of the top layers
A resin layer, wherein at least the lowermost layer and at least the uppermost layer are successively melt-extruded and coated by a sequential extrusion coating method, producing a support for an image material. It is an invention of a method.

13. In the twelfth aspect, in the at least two resin layers, at least the uppermost resin layer is melt-extruded and coated at 170 ° C to 290 ° C, and the resin layer contains titanium dioxide. The invention provides a method for producing a support for an image material, wherein the pigment is contained in an amount of 15% by weight or more.

14. In the above invention 12 or 13, in the resin layer composed of at least two layers, the resin layer composed of at least the lowermost layer is 290 ° C to 340 ° C.
And a method for producing a support for an image material, characterized in that the support is melt-extrusion coated.

15. In the above inventions 12 to 14, in the resin layer composed of at least two layers, the melt flow rate of the thermoplastic resin constituting each of the resin layers composed of at least the uppermost layer and the lowermost layer is 9 g / 10 min or more. An invention of a method for producing a support for an image material, characterized in that:

16. In the above inventions 12 to 15, when the resin layer composed of at least the lowermost layer and the resin layer composed of at least the uppermost layer are sequentially melt-extruded and coated by the sequential extrusion coating method, the preceding resin layer is rapidly After cooling by the cooling device,
An invention of a method for producing a support for an image material, characterized in that a subsequent resin layer is subjected to melt extrusion coating.

17. In the above invention 16, an invention of a method for manufacturing a support for an image material, characterized in that after cooling a preceding resin layer by a rapid cooling device, a subsequent resin layer is melt-extruded and coated within 10 seconds. is there.

18. In the above inventions 12 to 17, when the resin layer composed of at least the lowermost layer and the resin layer composed of at least the uppermost layer are sequentially melt-extruded and coated by a sequential extrusion coating method, the preceding resin layer is formed by corona. The present invention provides a method for producing a support for an image material, which comprises subjecting a subsequent resin layer to melt extrusion coating after corona discharge treatment by a discharge treatment device.

19. In the above invention 18, the preceding resin layer is subjected to corona discharge treatment by a corona discharge treatment device, and thereafter, the subsequent resin layer is melt-extruded and coated within 10 seconds. It is an invention of a method.

20. The invention according to any one of the inventions 12 to 19, wherein the traveling speed of the paper substrate is 260 m / min or more.

21. 20. The invention according to the twentieth aspect, wherein the running speed of the paper substrate is 330 m / min or more.

22. An invention of the above invention 21, wherein the traveling speed of the paper substrate is at least 400 m / min.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a support for an image material and a method for producing the same according to the present invention will be described in detail.

The present invention relates to a support for an image material, wherein a paper mainly composed of natural pulp is used as a substrate and at least one surface thereof is coated with a resin layer containing a thermoplastic resin, and a method for producing the same. A layer comprising at least two layers of a lowermost layer and an uppermost layer, and the resin layer is formed by sequentially extruding and coating the resin layer comprising at least the lowermost layer and the resin layer comprising at least the uppermost layer. An image material support suitable for high-speed melt extrusion coating and coated by an extrusion coating method, and a method for producing the same.

Conventionally, in a photographic printing paper support having two layers, the upper resin layer has a temperature of 170 ° C. to 290 ° C.
℃ melt extrusion coating, in the resin layer,
The resin layer comprising a specific amount of titanium dioxide pigment and comprising a lower layer is a photographic printing paper support coated by melt extrusion at 290 ° C. to 340 ° C., and the melt index of the upper water-resistant resin is lower. The support for photographic printing paper having a higher water-soluble resin melt index is already known.

However, these prior arts make it possible to produce a photographic printing paper support in high-speed melt extrusion coating of at most about 200 to 250 m / min. / Min or more, particularly 400 m / min or more, at the time of high-speed melt-extrusion coating, the unevenness of the release generated on the surface of the resin-coated paper due to the dilip stain and the deterioration of the releasability of the resin-coated paper from the cooling roll, It is not possible to produce a support for image materials, which does not have uneven print gloss and sufficiently satisfies the apparent glossiness, and has a remarkably high commercial value.

According to the present invention, there is provided an image material support comprising a resin layer comprising at least two layers on the image forming side.
The resin layer composed of at least the uppermost layer has a temperature of 170 ° C to 290 ° C.
C. The composition is melt-extruded and coated at 15 ° C., and the resin layer contains at least 15% by weight of a titanium dioxide pigment.
A support for an image material which has been sequentially melt-extruded and coated at 40 ° C., and preferably has an MFR of at least 9 g / m of a thermoplastic resin resin constituting at least a resin layer comprising an uppermost layer and a lowermost layer. This is a method for producing a support for an image material for 10 minutes or more.

In a particularly preferred embodiment of the present invention, when the resin layer comprising at least the lowermost layer and the resin layer comprising at least the uppermost layer are successively melt-extruded and coated by the sequential extrusion coating method, at least the lowermost layer is formed. Immediately after the formation of the resin layer, a quenching device cools the resin layer and then melt-extrudes and coats at least the uppermost resin layer.

According to the method for producing a support for an image material of the present invention, the running speed of the base paper is at least 260 m / min.
Furthermore, even in the case of high-speed melt extrusion coating at a speed of 330 m / min or more, particularly 400 m / min or more, it occurs on the surface of the resin-coated paper due to die lip stain during coating and deterioration of the releasability of the resin-coated paper from the cooling roll. The present invention provides an image material support having extremely high appearance value, which is free from uneven peeling, and hence glossiness of the image material and print, and which has an extremely excellent appearance, and further satisfies the quality of the image material and print sufficiently. can do.

The base paper used in the practice of the present invention is preferably a natural pulp paper mainly composed of ordinary natural pulp. Further, a mixed paper made of natural pulp as a main component and synthetic pulp and synthetic fiber may be used. Examples of such natural pulp include JP-A-58-37642 and JP-A-60-67.
It is advantageous to use appropriately selected natural pulp as described or exemplified in JP-A-940, JP-A-60-69649, JP-A-61-35442 and the like. Natural pulp was subjected to normal bleaching treatment of chlorine, hypochlorite, chlorine dioxide bleaching and alkali extraction or alkali treatment and, if necessary, oxidative bleaching treatment with hydrogen peroxide, oxygen, etc., and a combination treatment thereof Wood pulp of softwood pulp, hardwood pulp, and softwood pulp mixed pulp is advantageously used, and various pulp such as kraft pulp, sulfite pulp, and soda pulp can be used.

The base paper mainly composed of natural pulp used in the practice of the present invention can contain various additives at the time of preparing the stock slurry. Examples of the sizing agent include fatty acid metal salts or fatty acids, alkyl ketene dimer emulsions or epoxidized higher fatty acid amides, alkenyl or alkyl succinic anhydride emulsions described and exemplified in JP-B-62-7534, rosin derivatives, and the like. As a force enhancer, anionic, cationic or amphoteric polyacrylamide, polyvinyl alcohol, cationized starch, vegetable galactomannan, etc., as a wet paper strength enhancer, polyamine polyamide epichlorohydrin resin, etc., as a filler, clay, kaolin, Calcium carbonate,
Titanium oxide, water-soluble aluminum salts such as aluminum chloride and bansulfuric acid as fixing agents, caustic soda, sodium carbonate, sulfuric acid, etc. as pH adjusting agents.
It is advantageous to incorporate color pigments, coloring dyes, fluorescent brighteners and the like described or exemplified in JP-A-3-204251, JP-A-1-26637 and the like in an appropriate combination.

A composition comprising various water-soluble polymers or hydrophilic colloids or latexes, an antistatic agent and additives in or on a base paper mainly composed of natural pulp used in the practice of the present invention. Can be contained or applied by a size press, a tab size press, a blade coating, an air knife coating or the like. As a water-soluble polymer or hydrophilic colloid, starch-based polymers, polyvinyl alcohol-based polymers, gelatin-based polymers, polyacrylamide-based polymers, cellulose-based polymers, etc. described or exemplified in JP-A-1-26637, emulsions and latexes, Petroleum resin emulsion, JP 55
JP-A-4027, JP-A-1-108538 or an emulsion or latex of a copolymer containing at least ethylene and acrylic acid (or methacrylic acid) as constituents or styrene-butadiene,
Styrene-acrylic, vinyl acetate-acrylic, ethylene-vinyl acetate, butadiene-methyl methacrylate-based copolymers and emulsions or latexes of their carboxy-modified copolymers, as an antistatic agent,
Alkali metal salts such as sodium chloride and potassium chloride; alkaline earth metal salts such as calcium chloride and barium chloride;
Colloidal metal oxides such as colloidal silica, organic antistatic agents such as polystyrene sulfonate, etc., as pigments, clay, kaolin, calcium carbonate, talc, barium sulfate, titanium oxide, etc .;
It is advantageous to incorporate phosphoric acid, citric acid, caustic soda and the like, and the above-mentioned additives such as coloring pigments, coloring dyes and fluorescent brighteners in an appropriate combination.

The thickness of the base paper used in the practice of the present invention is not particularly limited, but its basis weight is 30 to 250 g.
/ M ² are preferred.

The base paper mainly composed of natural pulp used in the practice of the present invention may be a stylus type on the front side of the base paper from the viewpoint of remarkably improving the apparent glossiness of the image material and its print. JIS B using a three-dimensional surface roughness meter
Preferably, the center surface average roughness measured along the papermaking direction at a cutoff value of 0.8 mm by a measuring method in accordance with 0601 “Surface roughness—definition and indication” is 1.4 μm or less, preferably 1.3 μm. The following are more preferable, and
m or less, more preferably 1.1 μm or less.

The base paper having a center plane average roughness SRa of 1.4 μm or less is specifically prepared by using the following method, preferably combining two or more of the following methods, more preferably combining three or more of the following methods. It is obtained by using.

(1) As the natural pulp to be used, a sulphite pulp, which is easy to produce smoothness, preferably a hardwood sulphite pulp is often used. More specifically,
The hardwood sulfite pulp described or exemplified in JP-A-67940 is used in an amount of 30% by weight or more, preferably 50% by weight or more.

(2) A tension press is used during the drying of the wet paper. Specifically, for example, a multi-stage tension press as described or exemplified in JP-A-3-29945 is performed on the wet paper.

(3) Various water-soluble polymers, hydrophilic colloids or polymer latexes are contained or coated in or on the base paper. Specifically, various water-soluble polymers or hydrophilic colloids or polymer latexes are coated on a base paper or on a base paper by a size press or a tab size press, a blade coating, an air knife coating or the like to obtain a solid coating amount of 2%. .2
It is preferable to contain or coat g / m ² or more.

(4) After the base paper is formed, at least two or more series of calendering processes are performed on the base paper using a machine calendar, a super calendar, a heat calendar or the like. Specifically, for example, machine calendering or / and thermal machine calendering is performed on the base paper as a first series of calendering, and then machine calendering is further performed as necessary as a second series or later calendering. It is preferable to perform a thermal soft calendering process described or exemplified in JP-A-4-110939.

The side on which the image forming layer of the base material of the image material support in the present invention is provided (front side) is covered with a resin layer containing a thermoplastic resin. The back side of the base paper is preferably covered with a resin layer containing a thermoplastic resin. As the thermoplastic resin fat, resins such as polyolefin resin, polycarbonate resin, polyester resin, polyamide resin and a mixture thereof are preferable. Among them, from the viewpoint of melt extrusion coating properties, the above-mentioned polyolefin resin and / or polyester resin is preferable. More preferred are polyethylene resins. Further, it may be covered with a resin layer composed of an electron beam curable resin described or exemplified in JP-B-60-17104.

Examples of the polyethylene resin for the front resin layer and the back resin layer preferably used in the practice of the present invention include:
Low-density polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, linear low-density polyethylene resin, ultra-low-density polyethylene resin, ethylene and propylene, copolymers of α-olefins such as butylene, ethylene and acrylic acid, Ethyl acrylate, copolymers such as maleic anhydride, or graft copolymers, so-called carboxy-modified polyethylene resins, etc., and polyethylene based by high-pressure radical polymerization using an autoclave reactor, tubular reactor, etc. Examples include resins, polyethylene resins produced by polymerization using a metallocene polymerization catalyst, polyethylene resins produced by polymerization using a metal catalyst other than metallocene by Ziegler method, Phillips method, and the like, and mixtures thereof. As the polyethylene resin and the mixture, those having various densities, melt flow rates (hereinafter, the melt flow rate defined by JIS K 6760 is simply abbreviated as MFR), molecular weight, and molecular weight distribution can be used. Usually, the density of the resin component constituting the resin layer (in the case of a mixture, as a mixture) is in the range of 0.90 to 0.97 g / cm ³ , and the MFR is in the range of 9 g / 10 min to 50 g / 10 min, preferably Those having an MFR in the range of 9 g / 10 min to 40 g / 10 min, particularly preferably 9 g / 10 min to 20 g / 10 min, can be advantageously used alone or in combination.

The polyethylene resin polymerized and produced by the high-pressure method preferably used for the surface resin layer in the practice of the present invention includes long-chain branching by a high-pressure production method using an autoclave reactor, a tubular reactor, or the like. And various polyethylene resins having Examples of polyethylene resins polymerized and produced by these high-pressure methods include low-density polyethylene resins, medium-density polyethylene resins, propylene containing ethylene as a main component, copolymers with α-olefins such as butylene, carboxy-modified polyethylene resins, and the like. These are mixtures of various densities, MFRs, molecular weights,
Although those having a molecular weight distribution can be used, the density is usually 0.9.
0 to 0.95 g / cm ³ , MFR 9 g / 10 min.
50 g / 10 min, preferably with an MFR of 9 g / 10 min
40 g / 10 min, particularly preferably an MFR of 9 g / 10 min
Min to 20 g / 10 min can be used alone or as a mixture of two or more.

Examples of the polyethylene resin produced by polymerization using a metallocene polymerization catalyst particularly preferably used for the surface resin layer in the practice of the present invention include JP-A-3-502710, JP-A-60-35006, Tokuyo Sho 63-5
No. 01369, JP-A-3-234717, JP-A-3-234718, etc., the catalytic activity of a combination of a metallocene such as a zirconium or hafnium and preferably a methylaluminoxane is disclosed. The polymer was produced by polymerization using a polymer having a higher value as a polymerization catalyst. Polyethylene resins produced by polymerization using these metallocene polymerization catalysts include ultra-low-density polyethylene resin, low-density polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, linear low-density polyethylene resin, and ethylene as the main components. Propylene, a copolymer with an α-olefin such as butylene, a carboxy-modified polyethylene resin and the like, and mixtures thereof, with various densities, MFR, molecular weight,
Although those having a molecular weight distribution can be used, usually, the density is 0.8.
MFR in the range of 7 to 0.97 g / cm ³ and 9 g / 10 min.
50 g / 10 min, preferably with an MFR of 9 g / 10 min
40 g / 10 min, particularly preferably an MFR of 9 g / 10 min
Min to 20 g / 10 min can be used alone or as a mixture of two or more.

The polyethylene resin produced by polymerization using a metal polymerization catalyst other than the metallocene polymerization catalyst particularly preferably used for the surface resin layer in the practice of the present invention is, for example, produced by polymerization using Ziegler method, Phillips method or the like. Various polyethylene resins can be mentioned. Polyethylene resins produced by polymerization using metal polymerization catalysts other than those metallocene polymerization catalysts include ultra-low-density polyethylene resin, low-density polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, and linear low-density polyethylene. Resins, propylene containing ethylene as a main component, copolymers with α-olefins such as butylene, or carboxy-modified polyethylene resins and the like and mixtures thereof, and various densities, MFRs, molecular weights and molecular weight distributions can be used. However, usually, the density is 0.87 to 0.8.
Range of 97g / cm ^3, MFR is 9g / 10 minutes ~50g
/ 10 min, preferably 9 g / 10 min to 40 g MFR
/ 10 min, particularly preferably 9 g / 10 min to 2 MFR
Those having a range of 0 g / 10 minutes can be used alone or as a mixture of two or more.

As the polyethylene resin for the back resin layer used in the practice of the present invention, a compound resin prepared by melting and mixing in advance is preferable. As a method for preparing a compound resin by previously melting and mixing a low-density polyethylene resin or a medium-density polyethylene resin and a high-density polyethylene resin, a simple melt mixing method, a multi-stage melt mixing method, or the like can be used. For example, using an extruder, a twin-screw extruder, a heating roll mill, a Banbury mixer, a pressure kneader, and the like, a predetermined amount of low-density or medium-density polyethylene resin and high-density polyethylene resin, and if necessary, an antioxidant A method of adding various additives such as a lubricant, melting and mixing, and then pelletizing the mixture is advantageously used.

The thermoplastic resin in the surface resin layer and the back resin layer used in the support for an image material in the present invention is preferably a polyolefin resin, particularly preferably a polyethylene resin. It is manufactured by a so-called melt extrusion coating method in which a resin composition for the front resin layer and the back resin layer is cast into a film from a slit die and coated on a running base paper using a melt extruder. Usually, using a melt extruder on a running base paper, extruding the molten resin composition from the slit die into a film, casting and coating, pressure-bonded between a pressure roll and a cooling roll, It is produced in a series of steps of being separated from the chill roll. At the time of melt extrusion coating, the slit die is preferably a T-type die, an L-type die, or a flat die of a fishtail type die. The slit opening diameter is 0.1 mm to 2 m.
m is desirable. Further, the type of the multilayer co-extrusion die may be any type such as a feed block type, a multi-manifold type, a multi-slot type, and the like. In addition, the resin temperature of the lowermost layer is from 290 ° C.
340 ° C., and in that case, the temperature of the resin composition for the uppermost layer is preferably 170 ° C. to 290 ° C.

When the surface resin layer of the support for an image material in the present invention has a two-layer structure or a multilayer structure having more layers, the MFR of at least the uppermost layer and the lowermost layer of the thermoplastic resin may be used.
Is 9 g / 10 min to 50 g / 10 min, preferably MFR
Is from 9 g / 10 min to 40 g / 10 min, particularly preferably M
FR having a range of 9 g / 10 min to 20 g / 10 min, which is successively melt-extruded and coated by a sequential extrusion coating method (hereinafter, sometimes abbreviated as a tandem method), In this case,
It has been found that the effects of the present invention are very remarkably exhibited. That is, according to the method for manufacturing an image material support of the present invention in which the surface resin layer of the image material support has a two-layer structure or a multilayer structure having more layers, the running speed of the base paper is 260 m.
/ Min or more, even more than 330 m / min, especially 400 m / min.
Even with high-speed melt-extrusion coating for more than 1 minute, uneven release generated on the resin-coated paper surface due to die lip contamination during coating and deterioration of the releasability of the resin-coated paper from the cooling roll, and eventually image materials and prints It has been found that it is possible to produce an image material having excellent glossiness without any uneven glossiness and a support for an image material having an extremely high commercial value.

When the support for an image material of the present invention has a two-layer structure or a multilayer structure having more than two layers in the surface resin layer,
The MFR of the thermoplastic resin constituting each layer is MF before processing.
R represents the MFR of the mixture when it is a mixture. The same applies to the MFR in the back resin layer.

The support for an image material in the present invention has a multi-layer structure of two or more surface resin layers, but a two-layer structure is preferable in order to efficiently achieve the object of the present invention. . Further, the support for image materials having a multilayer structure having two or more surface resin layers may be manufactured by a sequential melt extrusion coating method, or a coextrusion coating method may be used except for the uppermost layer and the lowermost layer. A scheme may be used. In the present invention, at least the uppermost layer and the lowermost layer are characterized in that a support for an image material is manufactured by using a sequential extrusion coating method.

The resin layer of the image material support according to the present invention, in which the surface resin layer has a multilayer structure, includes an uppermost resin layer (hereinafter, may be simply referred to as an uppermost layer) and a lower lower layer. The resin layer (hereinafter, may be simply referred to as a lower resin layer) may have the same physical properties and composition, or may be different. Except for the uppermost layer and the lowermost layer (the lowermost resin layer), the polyethylene resin preferably used for the lower resin layer includes various densities, MFR,
Those having a molecular weight, a molecular weight distribution and the like can be used alone or as a mixture, and their physical properties may be the same or different. As the resin layer of the support for an image material according to the invention, the uppermost layer and the lowermost layer have an MFR of 9 g / 10 min to 50 g / 10 min, preferably an MFR of 9 g / 10 min to 40 g / 10 min, particularly Preferably, one having an MFR in the range of 9 g / 10 min to 20 g / 10 min is used alone or in combination of two or more.

For example, as the polyethylene resin in the uppermost layer, its MFR (when two or more kinds are contained, the MFR as a mixture, hereinafter the same meaning) is 30 g / 1.
0 minutes, higher than the MFR of the polyethylene-based resin in the lower resin layer (excluding the lowermost layer) (if two or more kinds are contained, the MFR as a mixture; hereinafter the same meaning) , Low (however, MFR is 9 g / 10 min or more) or the same can be used. For example, the polyethylene resin in the uppermost layer has an MFR of 10 g / 10 min to 50 g / 10 min, and the polyethylene resin in the lower resin layer (excluding the lowermost layer) has an MFR of 2 g / 10 min. Min to 10 g / 10 min, and the polyethylene resin in the uppermost layer has an MFR of 10 g / 10 min to 20 g / 10 min,
As the polyethylene resin in the lower resin layer, MFR is 1
0g / 10min ~ 50g / 10min can also be used,
Further, those having the same MFR can also be used. The lowermost layer has an MFR of 9 g / 10 min to 50 g / 10 min, preferably an MFR of 9 g / 10 min to 40 g / 10 min, particularly preferably an MFR of 9 g / 10 min to 20 g / 10 min. .

The method for producing a support for an image material of the present invention comprises:
The surface of the base paper is composed of at least two layers of a lowermost layer and an uppermost layer, and the resin layer is formed by coating a resin layer composed of at least a lowermost layer and a resin layer composed of at least an uppermost layer by a tandem method. Preferably, the resin layer consisting of the uppermost layer is one coated by melt extrusion at 170 ° C. to 290 ° C., wherein the resin layer contains at least 15% by weight of a titanium dioxide pigment, The layer is characterized by being melt extruded at 290 ° C. to 340 ° C. More preferably, the resin layer consisting of the uppermost layer and the lowermost layer, the melt flow rate of the thermoplastic resin constituting each,
Each is characterized by being at least 9 g / 10 minutes.

In the method for producing a support for an image material of the present invention, when the resin layer composed of at least the lowermost layer and the resin layer composed of at least the uppermost layer are coated by a tandem method, at least the resin layer composed of the lowermost layer is formed. It is a particularly preferred embodiment that the resin layer composed of at least the uppermost layer is melt-extruded and coated immediately after the resin layer is cooled by the rapid cooling device immediately after the formation.

The rapid cooling device used in the present invention comprises:
In the melt extrusion coating, any device may be used as long as it is quenched immediately after the resin layer comprising the lowermost layer is formed online. For example, two or more cooling rolls may be provided, or a quenching chamber (filled with liquid nitrogen as an example) may be provided on a running paper web to perform quenching, or a quenching substance such as liquid nitrogen may be provided. Immediately after the lowermost resin layer is formed, it may be cooled rapidly by a rapid cooling device such as spraying. Further, these cooling devices may be used in combination of many or several types.

At this time, the cooling time is preferably such that after the preceding resin layer is cooled by the rapid cooling device, the subsequent resin layer is melt-extruded and coated within 10 seconds. When a large number or a combination of a plurality of cooling devices are used, the subsequent resin layer is preferably melt-extruded and coated within 10 seconds after being cooled by the final cooling device.

When the resin layer composed of at least the lowermost layer and the resin layer composed of at least the uppermost layer are successively melt-extruded and coated by a sequential extrusion coating method, the preceding resin layer is coated with a corona discharge treatment device. After the corona discharge treatment, the subsequent resin layer is preferably subjected to melt extrusion coating.
At this time, many or several types of corona discharge treatment devices may be used in combination.

After the preceding resin layer is subjected to corona discharge treatment by the corona discharge treatment device, the subsequent resin layer is preferably subjected to melt extrusion coating within 10 seconds.

At this time, the corona discharge treatment time is preferably such that the preceding resin layer is subjected to corona discharge treatment by a corona discharge treatment device, and then the subsequent resin layer is melt-extruded and coated within 10 seconds. . When a large number or a combination of several types of corona discharge treatment devices are used, after the corona discharge treatment by the final corona discharge treatment device, the subsequent resin layer is melt-extruded and coated within 10 seconds. Good.

Further, when the above-mentioned rapid cooling device and corona discharge treatment device are used together, it is even more effective.

In the conventional method for producing a support for an image material, particularly a support for a photographic printing paper, the running speed of the base paper is at most 200 m / min to 250 even if it is called high-speed resin coating.
m / min. One of the causes is the suitability of resin for melt extrusion. When the surface resin layer of the image material support has a multi-layer structure of two or more layers, it is generally manufactured by co-extrusion coating. In this case, the upper layer containing the titanium dioxide pigment is replaced with the lower layer. It is usual to apply the resin at a lower temperature. By applying such a temperature difference to the melt extrusion coating, the occurrence of die lip stain of the melt extruded film due to the resin composition for the upper layer containing the titanium dioxide pigment and the peeling unevenness due to the cooling roll stain are reduced as much as possible. Was to be done. However, in the case of co-extrusion coating, the upper and lower layers of the resin or resin composition are melt-extruded and coated on the base paper in a state where the two layers are in direct contact with each other. Rather, the upper layer is melt extruded at a relatively high temperature. In such a state, the occurrence of die lip contamination and uneven peeling are not surprisingly suppressed. The tandem method is effective in improving this.

In high-speed resin coating in melt extrusion coating in a tandem system, there is a problem in terms of resin characteristics itself. Usually, the MFR of the resin composition used for the upper layer is the MF of the resin or the resin composition used for the lower layer.
Those with a relatively high MFR compared to R are used. Although there is one purpose of improving the deterioration of fluidity due to various compositions contained in the resin by using a resin having a relatively high MFR, in high-speed resin coating, a high MFR is required. It is a necessary factor to use a resin having the same. When a resin having a low MFR is used for high-speed resin coating, high-speed resin coating cannot be performed so much in terms of fluidity, and in extreme cases, the resin is cut off, making high-speed resin coating impossible.

In the method for producing a support for an image material of the present invention, each of the resin layers comprising the uppermost layer and the lowermost layer has a thermoplastic resin resin having an MFR of 9 g.
It is characterized by using a relatively high MFR of / 10 min or more, and since the fluidity of the two layers substantially coincides with each other, it is considered that high-speed resin coating is suitably performed. At this time, the MFR of the thermoplastic resin constituting the resin layer composed of the uppermost layer and the lowermost layer was 9 g / 10
It is preferable that the MFR of the uppermost resin layer is slightly higher than the MFR of the lowermost resin layer. The MFR of the uppermost resin layer is 9 to 20, and the MF of the lowermost resin layer is
R is preferably from 9 to 15.

The support for an image material of the present invention thus produced has a paper substrate traveling speed of 260 m / min or more,
Furthermore, even with a high-speed melt extrusion coating of 330 m / min or more, especially 400 m / min or more, peeling unevenness generated on the resin-coated paper surface due to die lip stain and deterioration of the releasability of the resin-coated paper from the cooling roll, and Thus, it is possible to provide a support for an image material having extremely high commercial value, which is free from unevenness in gloss of an image material and a print, has an extremely excellent glossiness, and sufficiently satisfies the quality of the image material and a print. Things.

In the support for an image material and the method for producing the same according to the present invention, the density of the polyethylene resin in the uppermost layer (when two or more kinds are contained, the density as a mixture; ) Is higher, lower or the same as the density of the polyethylene resin in the lower resin layer (when two or more types are contained, the density as a mixture, hereinafter the same meaning). Can be done. For example, those as polyethylene resin in the top layer, density of ^{0.925g / cm 3 ~0.970g / cm 3} ,
As the polyethylene resin in the lower resin layer, the density is 0.
It can be used those ^{870g / cm 3 ~0.925g / cm 3} , whereas the polyethylene resin in the top layer, that the density of ^{0.870g / cm 3 ~0.925g / cm 3} ,
As the polyethylene resin in the lower resin layer, the density is 0.
925 g / cm ^{3 to} 0.970 g / cm ³ can be used, and those having the same density can be used.

As the polyethylene resin in the uppermost layer, at least one of those having a melting point higher, lower or the same as the melting point of the polyethylene resin in the lower resin layer can be used. For example, a polyethylene resin having a melting point of 115 ° C. or more can be used as the polyethylene resin in the uppermost layer, and a polyethylene resin having a melting point of less than 115 ° C. can be used as the polyethylene resin in the lower resin layer. As the polyethylene-based resin in the lower resin layer, those having a melting point of 115 ° C. or more can be used, and those having the same melting point can be used.

Particularly preferred resin layers having a multilayer structure of the image material support in the present invention include the effects of the present invention, that is, the effect of improving the apparent glossiness of the image material having the support and the print thereof, and the releasability. From the viewpoint that the improvement effect can be extremely remarkably exhibited, as the polyethylene resin in the uppermost layer, the density is higher than that of the polyethylene resin in the lower resin layer by using at least one kind, or However, using at least one of those having a melting point higher than the melting point of the polyethylene resin in the lower resin layer, or using at least one of those having a density and melting point higher than those of the polyethylene resin in the lower resin layer Is preferred.

Various additives can be contained in the front resin layer and, if necessary, in the back resin layer of the support for image materials in the present invention. For the purpose of improving the whiteness of the support and the sharpness of the image, JP-B-60-3430, JP-B-63-11655, and JP-B1-382.
No. 91, Japanese Patent Publication No. 1-38292,
It is preferable to include a titanium dioxide pigment described or exemplified in Japanese Patent No. 105245 or the like. Also, in addition to titanium dioxide, zinc oxide, talc, white pigments such as calcium carbonate, as a releasing agent, stearic acid amide, fatty acid amides such as arachidic amide, as a dispersant and releasing agent for the pigment, zinc stearate, Fatty acid metal salts such as calcium stearate, aluminum stearate, magnesium stearate, zinc palmitate, zinc myristate, calcium palmitate, and the like, hindered phenols, hindered amines, phosphorus compounds, and sulfur described or exemplified in JP-A-1-105245 Various antioxidants, blue pigments and dyes such as cobalt blue, ultramarine blue, celian blue and phthalocyanine blue, magenta pigments and dyes such as cobalt violet, fast violet and manganese violet, JP-A-2-254440. Gazette According or illustrative of the fluorescent brightening agent, various additives as appropriate combination can be incorporated such as an ultraviolet absorber. These additives are preferably contained as a resin masterbatch or compound. Further, from the viewpoint of the sharpness or whiteness of the print or the heat resistance of the image material support, effective improvement of light resistance or release properties, etc., white pigments such as titanium oxide and fluorescent brighteners, coloring pigments and the like. It is preferable to incorporate a coloring dye or other additives such as an antioxidant, an ultraviolet absorber or a release agent at a higher concentration in the uppermost layer than in the lower resin layer. In particular, the content of titanium dioxide pigment in the uppermost layer (as a percentage of the weight in the uppermost layer) is 9% by weight or more, further 12% by weight or more, still more preferably 15% by weight or more, especially 17% by weight or more. Is preferred.

In the practice of the present invention, it is preferable that the base paper is subjected to an activation treatment such as a corona discharge treatment or a flame treatment before the front and back resin compositions are coated on the base paper. Further, as described in JP-B-61-42254, a resin layer may be coated on a running base paper after spraying an ozone-containing gas onto a molten resin composition in contact with the base paper. In addition, the front and back resin layers are sequentially, preferably continuously, extrusion-coated, and are preferably coated on the base paper by a so-called tandem extrusion coating method. If necessary, the back resin layer is also two or more layers. May be coated with a multilayer structure. The surface resin layer surface of the image material support can be processed into a glossy surface, a finely rough surface described in JP-B-62-19732, a matte surface or a silk surface, and the back resin layer is usually matt. It is preferable to process the surface.

The coating thickness of the surface resin layer of the image material support in the present invention is usefully in the range of 8 to 100 μm, preferably in the range of 12 to 60 μm, and more preferably in the range of 18 to 40 μm.
The range of μm is particularly preferred. Further, a particularly preferred image material support in the present invention, the resin layer is at least a resin layer composed of at least the lowermost layer and a resin layer composed of at least the uppermost layer in the case of a multi-layer structure coated by sequential melt extrusion coating, at least The thickness of the lowermost resin layer is preferably 25% or more, more preferably 39% or more of the total resin layer thickness on the front side, from the viewpoint of improving the apparent glossiness of the image material and its print. The thickness is more preferred, and a thickness of 50% or more is particularly preferred, but is not particularly limited. Also, the back side of the base paper is preferably coated with a back resin layer containing a resin capable of forming a film as a main component, and the resin is preferably a polyethylene-based resin. In particular, it is preferable to set appropriately within a range for obtaining curl balance.
A range of 100 μm is useful, but preferably 12-6.
The range is 0 μm.

The surface of the surface resin layer of the support for an image material according to the present invention is subjected to an activation treatment such as a corona discharge treatment or a flame treatment, and then to JP-A-61-84643 and JP-A-1-92740. An undercoat layer described or exemplified in Japanese Patent Application Laid-Open, JP-A-1-102551, JP-A-1-16635 or the like can be applied. Further, on the back resin layer surface of the image material support in the present invention, after performing an activation treatment such as a corona discharge treatment, a flame treatment, various back coat layers are coated for antistatic and the like. Can be. In addition, the back coat layer includes a Japanese Patent Publication No. 52-1.
No. 8020, JP-B-57-9059, JP-B-57-53940, JP-B-58-56859, JP-A-59-214849, JP-A-58-1
84144 and the like or the inorganic antistatic agents described or exemplified, organic antistatic agents, hydrophilic binders, latex,
A curing agent, a pigment, a surfactant and the like can be appropriately combined and contained.

The support for an image material in the present invention is coated with various photographic constituent layers and is used for color photographic paper, black and white photographic paper, typesetting photographic paper, copy photographic paper, reversal photographic material, The silver salt diffusion transfer method can be used for various purposes such as negative and positive, and printing materials. For example, a silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide emulsion layer can be provided. The silver halide photographic emulsion layer may contain a color coupler to provide a multilayer silver halide color photographic constituting layer. Further, a photographic component layer for silver salt diffusion transfer method can be provided. As a binder for these photographic constituent layers, in addition to ordinary gelatin, hydrophilic high-molecular substances such as polyvinylpyrrolidone, polyvinyl alcohol and polysaccharide sulfate compounds can be used. Further, the above-mentioned photographic constituent layer can contain various additives. For example, as a sensitizing dye, a cyanine dye, a merocyanine dye, etc., as a chemical sensitizer, a water-soluble gold compound, a sulfur compound, etc., as an antifoggant or stabilizer, a hydroxy-triazolopyrimidine compound, a mercapto-heterocyclic compound, etc. , Hardening agents such as formalin, vinylsulfone compounds and aziridine compounds, coating aids such as alkylbenzenesulfonates and sulfosuccinate salts, etc., dialkylhydroquinone compounds etc. as antifouling agents, and other fluorescent brighteners, improving sharpness Dyes, antistatic agents, pH adjusters,
A fogging agent and a water-soluble iridium compound, a water-soluble rhodium compound, and the like can be added in appropriate combination during the generation and dispersion of silver halide.

The photographic material according to the present invention is subjected to exposure, development, and stoppage according to the photographic material, as described in "Photosensitive Material and Handling Method" (Kyoritsu Shuppan, Goro Miyamoto, Photographic Technology Course 2). , Fixing, bleaching, and stabilization. Further, the multi-layer silver halide color photographic material may be treated with a developer containing a development accelerator such as benzyl alcohol, thallium salt, phenidone or the like, or may be treated with a developer substantially free of benzyl alcohol. it can.

The support for an image material in the present invention can be used as a support for various heat transfer type thermal transfer recording image receiving materials by coating various heat transfer type thermal transfer recording image receiving layers. Examples of the synthetic resin used for the heat transfer type thermal transfer recording image receiving layer include ester bonds such as polyester resin, polyacrylate resin, polycarbonate resin, polyvinyl acetate resin, polyvinyl butyral resin, styrene acrylate resin, and vinyl toluene acrylate resin. , A resin having an amide bond such as a polyamide resin, a resin having a urea bond such as a urea resin, other polycaprolactam resins, styrene resins, polyvinyl chloride resins, and vinyl chloride. -Vinyl acetate copolymer resin, polyacrylonitrile resin and the like. In addition to these resins,
Mixtures or copolymers of these can also be used.

In the heat transfer type thermal transfer recording image receiving layer according to the present invention, a releasing agent, a pigment and the like may be added in addition to the synthetic resin. As the release agent, polyethylene wax, amide wax, solid waxes such as Teflon powder,
Fluorine-based, phosphate-based surfactants, silicone oils, and the like. Among these release agents, silicone oil is most preferred. As the above silicone oil,
An oily substance can be used, but a curable type is preferred. Examples of the curable silicone oil include a reaction curable type, a photocurable type, and a catalyst curable type, and a reaction curable type silicone oil is particularly preferable. Examples of the reaction-curable silicone oil include an amino-modified silicone oil and an epoxy-modified silicone oil. The amount of the reactive silicone oil added is 0.1 to 20% by weight in the image receiving layer.
Is preferred. As the pigment, extenders such as silica, calcium carbonate, titanium oxide, and zinc oxide are preferable. The thickness of the image receiving layer is preferably 0.5 to 20 μm, more preferably 2 to 10 μm.

The support for an image material in the present invention can be used as a support for various ink jet recording materials by coating various ink image receiving layers. Various binders can be contained in the ink image receiving layer for the purpose of improving the drying property of the ink, the sharpness of the image, and the like. Specific examples of the binder include lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, and gelatin derivatives such as various gelatins such as phthalic acid, maleic acid, and gelatin reacted with an anhydride of dibasic acid such as fumaric acid. , Ordinary polyvinyl alcohol of various saponification degrees,
Carboxy-modified, cationic-modified and amphoteric polyvinyl alcohols and their derivatives, starches such as oxidized starch, cationized starch, etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, polyvinylpyrrolidone, polyvinylpyridium halide, polyacryl Synthetic polymers such as acid soda, acrylic acid methacrylic acid copolymer salt, polyethylene glycol, polypropylene glycol, polyvinyl ether, alkyl vinyl ether / maleic anhydride copolymer, styrene / maleic anhydride copolymer and salts thereof, and polyethyleneimine Conjugated diene copolymer latex such as styrene / butadiene copolymer, methyl methacrylate / butadiene copolymer, polyvinyl acetate, vinyl acetate
Vinyl acetate polymer latex such as maleic acid ester copolymer, vinyl acetate / acrylic acid ester copolymer, ethylene / vinyl acetate copolymer, acrylic acid ester polymer, methacrylic acid ester polymer, ethylene / acrylic acid ester Acrylic polymer or copolymer latex such as copolymer, styrene / acrylate copolymer, vinylidene chloride copolymer latex or functional group-containing monomer such as carboxyl group of these various polymers Aqueous adhesives such as thermosetting synthetic resin such as functional group-modified polymer latex, melamine resin and urea resin, and polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride / vinyl acetate copolymer, polyvinyl butyral, and alkyd Synthetic resin adhesive such as resin, -24906, JP-A No. 3-
Inorganic binders such as alumina sol, silica sol and the like described or exemplified in Japanese Patent Application No. 281383 and Japanese Patent Application No. 4-240725 can be used alone or in combination.

The ink receiving layer of the ink jet recording material according to the present invention may contain various additives in addition to the binder. For example, as a surfactant, an anionic surfactant such as a long-chain alkyl benzene sulfonate, a long-chain, preferably a branched alkyl sulfosuccinate, a polyalkylene oxide of a long-chain, preferably a branched alkyl group-containing phenol. Nonionic surfactants such as ethers and polyalkylene oxide ethers of long-chain alkyl alcohols;
No. 303, U.S. Pat. No. 3,589,906, etc., such as fluorinated surfactants such as .gamma.-aminopropyltriethoxysilane, N-.beta. (Aminoethyl) .gamma.
As a silane coupling agent such as aminopropyltrimethoxysilane, a polymer hardening agent, an active halogen compound, a vinyl sulfone compound, an aziridine compound, an epoxy compound, an acryloyl compound, an isocyanate compound, etc .; 1-1102551
And P-hydroxybenzoic acid ester compounds, benzisothiazolone compounds, and isothiazolone compounds described in JP-A-63-204251, JP-A-1-26637, and the like or the coloring pigments and coloring dyes described or exemplified in Antioxidants such as fluorescent whitening agents, sodium hydroxymethanesulfonate and sodium P-toluenesulfinate as yellowing inhibitors, and benzotriazole compounds having a hydroxy-dialkylphenyl group at the 2-position as ultraviolet absorbers. As an agent, JP-A No. 1-10
No. 5245 or an example of a polyhindered phenol compound such as a polyhindered phenol compound, as a pencil writing agent, an organic or inorganic particle size of starch particles, barium sulfate, silicon dioxide, etc.
Fine particles of 2 to 5 μm, organopolysiloxane compounds described or exemplified in Japanese Patent Publication No. 4-1337, pH
Caustic soda, sodium carbonate, sulfuric acid, hydrochloric acid,
Various additives such as octyl alcohol and silicon-based antifoaming agents such as phosphoric acid and citric acid can be appropriately combined and contained.

[0095]

EXAMPLES The present invention will be described below in detail with reference to examples, but the contents of the present invention are not limited to the examples.

<Manufacture of paper> Hardwood bleached kraft pulp 8
5% by weight and 15% by weight of hardwood bleached sulfite pulp
Length of pulp after beaten mixed pulp consisting of
AN TAPPI Paper Pulp Test Method No. After beating so that the length-weighted average fiber length measured in accordance with 52-89 "Paper and Pulp Fiber Length Test Method" is 0.60 mm, 100 parts by weight of pulp is cationized. Starch 3
Parts by weight, 0.2 parts by weight of anionic polyacrylamide,
A stock slurry was prepared by adding 0.4 parts by weight of an alkyl ketene dimer emulsion (as a ketene dimer component), 0.4 parts by weight of a polyamine polyamide epichlorohydrin resin and appropriate amounts of a fluorescent whitening agent, a blue dye and a red dye. .
Thereafter, the stock slurry is placed on a fourdrinier paper machine running at 200 m / min, and a paper web is formed while giving appropriate turbulence, and the linear pressure is adjusted in the range of 15 to 100 kgf / cm in the wet part. After performing a three-stage wet press,
Treat with smoothing rolls, and in the subsequent drying part, 3
After performing a two-stage tension press in which the linear pressure was adjusted in the range of 0 to 70 kgf / cm, the resultant was dried. Then, during the drying, 25 g / size press solution composed of 2 parts by weight of carboxy-modified polyvinyl alcohol, 0.05 parts by weight of fluorescent whitening agent, 0.002 parts by weight of blue dye, 4 parts by weight of sodium chloride and 94 parts by weight of water. m ² size was pressed, eventually paper resulting water and dried so that 8 wt% absolute dry moisture content, and the machine calender treatment at the linear pressure of 70 kgf / cm, a basis weight 160g
An image material support paper having a center surface average roughness (SRa) of 1.30 μm / m ² was produced.

<Formation of Backside Resin Layer> Next, after a corona discharge treatment is applied to the paper surface (backside) opposite to the side on which the image forming layer is coated, a low-density polyethylene resin (density = 0.
30 parts by weight of 924 g / cm ³ , MFR = 1 g / 10 min) and a high-density polyethylene resin (density = 0.967 g / c)
(m ³ , MFR = 15 g / 10 min) 70 parts by weight of the compound resin composition was melt-extruded and coated at a resin temperature of 320 ° C. to a resin thickness of 25 μm while adjusting the running speed of the paper to the processing speed of the surface resin layer. At this time, the cooling roll
A surface roughened by a liquid honing method and having a center surface average roughness (SRa) of 1.15 μm on the back layer surface after the application of the following back layer was used.

For the back layer, the following back layer coating solution was applied by on-machine coating after the back surface resin layer was subjected to corona discharge treatment. As a dry weight, a back layer coating liquid containing colloidal silica: styrene-based latex = 1: 1, and further containing 0.021 g / m ² of sodium polystyrene sulfonate and an appropriate amount of a coating aid was added to the latex (solid). It was applied at a coating amount of 0.21 g / m ² as calculated by weight.

<Formation of Multilayer Resin Layer for Surface by Tandem Method (1)> Resin composition (R1): 70 parts by weight of high-density polyethylene resin (density 0.967 g / cm ³ , MFR = 9 g / 10 min) Density polyethylene resin (density 0.924 g / c
(m ³ , MFR = 9 g / 10 min) 30 parts by weight using a melt extruder to melt and mix in advance, and used as pellets.

Resin composition (R2): low density polyethylene resin by tubular method (density 0.918 g / cm ³ , MFR =
9 g / 10 minutes, melting point: 108 ° C.) 47.5% by weight, 50% by weight of anatase type titanium dioxide pigment surface-treated with hydrous aluminum hydroxide (0.50% by weight as Al 2 O 3 based on titanium dioxide) and zinc stearate 2.5% by weight and an antioxidant, tetrakis [methylene-3 (3,3
A titanium dioxide pigment masterbatch comprising 150 ppm of [5-di-tert-butyl-4-hydroxyphenyl) propionate] methane was prepared.

Examples 1 to 3 The resin composition (R1) was put into a hopper of a melt-extrusion coater and subjected to corona discharge treatment on the surface of the support on which the backside resin layer was formed. 320 ° C., resin thickness 13 μm, mirror-finished cooling roll (cooling water temperature 11 ° C.)
And a press roll under a linear pressure of 40 kgf / cm under the conditions shown in Table 1 to form a lower resin layer. Subsequently, after 66 parts by weight of the resin composition (R1) and 34 parts by weight of the resin composition (R2) were sufficiently kneaded in a blender, the mixture was put into a hopper of a melt extrusion coating machine, and the resin temperature was 290 ° C and the resin thickness was 290 ° C. Using a 17 μm, mirror-finished cooling roll (the conditions are the same as those for the lower layer), melt extrusion coating under the conditions shown in Table 1 to form an upper resin layer, and producing the image material supports of Examples 1 to 3 of the present invention. did.

<Formation of Coextrusion Multilayer Resin Layer for Surface (1)> Resin composition (R3): 70 parts by weight of high-density polyethylene resin (density 0.967 g / cm ³ , MFR = 5 g / 10 min) Density polyethylene resin (density 0.924 g / c
(m ³ , MFR = 5 g / 10 min) 30 parts by weight using a melt extruder to melt and mix in advance, and was used as pellets.

Resin composition (R4): tubular method low density polyethylene resin (density 0.918 g / cm ³ , MFR =
47.5% by weight of 5 g / 10 minutes, melting point 108 ° C.) 50% by weight of anatase type titanium dioxide pigment surface-treated with hydrous aluminum hydroxide (0.50% by weight as Al2 O3 relative to titanium dioxide) and zinc stearate 2.5% by weight and an antioxidant, tetrakis [methylene-3 (3,3
A titanium dioxide pigment masterbatch comprising 150 ppm of [5-di-tert-butyl-4-hydroxyphenyl) propionate] methane was prepared.

Comparative Examples 1 to 3 Table 1 was prepared in the same manner as in Examples 1 to 3, except that the co-extruder was used, and that the resin composition (R3) and the resin composition (R4) were used. The melt-extrusion coating was carried out under the following conditions to produce the support for an image material of Comparative Examples 1 to 3 outside the present invention. However, at this time, the temperature of the die block in contact with the lower layer of the co-extruder was 320 ° C., and the temperature of the die block in contact with the upper layer was 290 ° C.

Comparative Example 4 Except for using the resin composition (R1) and the resin composition (R2) described above, a melt extrusion coating was carried out under the conditions shown in Table 1 in the same manner as in Comparative Example 3; A support for an image material outside the present invention was produced.

The characteristic values of each of the thus obtained Examples and Comparative Examples were obtained by the following test methods.

The die lip stain was evaluated by the method described below.

With respect to the seven types of the support for the image material of the present invention in Examples 1 to 3 and the support for the image material other than the present invention in Comparative Examples 1 to 4, the die lip stain generated on the die lip after the production for one hour. Was measured. If the number is two or less, there is no problem in actual operation, but if the number is five or more, there is a problem in actual operation. When three or four lines are generated, short-term operation is possible, but long-term operation is impossible.

The peeling unevenness was evaluated by the method described below.

With respect to the seven types of the support for the image material of the present invention in Examples 1 to 3 and the support for the image material other than the present invention in Comparative Examples 1 to 4, the support for each image material after one hour of production was obtained. The surface state of the mirror surface on the front side of the body was observed with oblique light, the degree of occurrence of peeling unevenness was visually judged by a monitor of 10 persons, and a 10-grade evaluation was performed. The evaluation criteria (the larger the grade value, the smaller the occurrence of uneven peeling, and the smaller the grade value, the greater the occurrence of uneven peeling) are as follows.

Grades 10 to 9: Extremely good, with very little or no uneven peeling. Grade 8 to 7: Less occurrence of peeling unevenness and good. Grade 6 to 5: Although uneven peeling occurs slightly, it is practical. Grade 4-1: There are many occurrences of uneven peeling, and there is a problem in practical use.

Next, the method for evaluating the apparent glossiness of a photographic print having a support for an image material was evaluated by the method described below.

A blue-sensitive emulsion layer containing a yellow color coupler, an intermediate layer containing a color-mixing inhibitor, a green emulsion layer containing a magenta color coupler, and an ultraviolet absorber are arranged in this order on the support for the image material. An ultraviolet absorbing layer, a red-sensitive emulsion layer containing a cyan color coupler, and a protective layer were applied by an E-bar for multilayer coating to prepare a color photographic paper having a total amount of gelatin of 7 g / m ² . Each color-sensitive emulsion layer contains silver chlorobromide equivalent to 0.6 g / m ^{2 of} silver nitrate, and further contains gelatin necessary for the formation, dispersion and film formation of silver halide, as well as an appropriate amount of an antifoggant,
It contains sensitizing dyes, coating aids, hardeners, thickeners and appropriate amounts of filter dyes.

Next, the prepared color photographic paper was stored at 35 ° C. and normal humidity for 5 days, and then a group photograph was baked, developed, bleached and fixed, developed stably, and then dried to produce a photographic print. . Alternatively, burned samples of white solid (unexposed) and black solid (black color) were separately prepared. In addition, a series of processes of exposure, development, and drying were performed by an automatic printer and an automatic developing machine. Note that the color development processing is performed by color development (4
5 seconds) → Bleaching / fixing (45 seconds) → Stable (1 minute 30 seconds) →
The drying procedure was performed.

With respect to the obtained group photograph, white solid and black solid photographic prints, the visual glossiness of the photographic prints was visually judged comprehensively by 10 monitors, and 1
Grade evaluation was performed on a scale of 0. The evaluation criteria (the higher the grade value, the higher the apparent glossiness, and the lower the grade value, the lower the apparent glossiness) are as follows.

Grades 10 to 9: Very or very high apparent glossiness. Grade 8 to 6: High glossiness in appearance. Grade 5-4: The glossiness is slightly low in appearance, but practical. Grade 3-1: The appearance has a low glossiness, and there is a problem in practical use.

Table 1 shows the test results thus obtained.

[0118]

[Table 1]

Example 4 A support for an image material of the present invention of Example 4 was produced in the same manner as in Example 2 except that two of the above-mentioned cooling rolls were successively juxtaposed online. did.

Example 5 A support for an image material of the present invention of Example 5 was produced in the same manner as in Example 2 except that corona discharge treatment was performed instead of the cooling roll. .

Example 6 The procedure of Example 6 was repeated, except that two cooling rolls were continuously arranged online and corona discharge treatment was performed in the same manner as described above. A support for an image material of the invention was produced.

Table 2 shows the test results of the samples of Examples 4 to 6 thus obtained.

[0123]

[Table 2]

Example 7 In the same manner as in Example 5, except that the liquid nitrogen spray was used instead of the corona discharge treatment.
A support for an image material of the present invention of Example 7 was produced. As a result of testing the sample, good results similar to those of Example 5 were obtained.

<Formation of Multilayer Resin Layer for Surface by Tandem Method (2)> Resin composition (R5): 70 parts by weight of high-density polyethylene resin (density 0.967 g / cm ³ , MFR = 20 g / 10 min) Density polyethylene resin (density 0.924 g / c
(m ³ , MFR = 20 g / 10 min) 30 parts by weight using a melt extruder before melting and mixing, and used as pellets.

Resin composition (R6): tubular low-density polyethylene resin (density 0.918 g / cm ³ , MFR =
20 g / 10 min, melting point 108 ° C.) 47.5% by weight, 50% by weight of anatase type titanium dioxide pigment surface-treated with hydrous aluminum hydroxide (0.50% by weight as Al 2 O 3 based on titanium dioxide) and zinc stearate 2.5% by weight and an antioxidant, tetrakis [methylene-3
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] A titanium dioxide pigment masterbatch comprising 150 ppm of methane was prepared.

Example 8 A resin composition (R5) was put into a hopper of a melt-extrusion coating machine, and a corona discharge treatment was applied to the surface of the support on which the above-mentioned backside resin layer was formed. 13 μm thick resin, mirror-finished cooling roll (cooling water temperature 11 ° C.)
And a press roll under a linear pressure of 40 kgf / cm under the conditions shown in Table 1 to form a lower resin layer. Subsequently, 62 parts by weight of the resin composition (R5) and 38 parts by weight of the resin composition (R6) were sufficiently kneaded in a blender, and then charged into a hopper of a melt-extrusion coating machine. A 17 μm, mirror-surfaced cooling roll (the conditions were the same as for the lower layer) was applied by melt extrusion coating under the conditions shown in Table 3 to form an upper resin layer, and the image material support of the present invention of Example 8 was produced. However, at this time, after forming the lower resin layer, liquid nitrogen gas was sprayed on the lower resin layer surface from the spraying device 2 seconds after the lower resin layer was formed, and further 2 seconds later, the upper resin layer was formed.

<Formation of Coextrusion Multilayer Resin Layer for Surface (2)> Resin composition (R7): 70 parts by weight of high-density polyethylene resin (density 0.967 g / cm ³ , MFR = 4 g / 10 min) Density polyethylene resin (density 0.924 g / c
(m ³ , MFR = 4 g / 10 min) 30 parts by weight using a melt extruder to melt and mix in advance, and used as pellets.

Resin composition (R8): low density polyethylene resin by tubular method (density 0.918 g / cm ³ , MFR =
47.5% by weight of 7g / 10 minutes, melting point of 108 ° C.), 50% by weight of anatase type titanium dioxide pigment surface-treated with hydrous aluminum hydroxide (0.50% by weight as Al2 O3 relative to titanium dioxide) and zinc stearate 2.5% by weight and an antioxidant, tetrakis [methylene-3 (3,3
A titanium dioxide pigment masterbatch comprising 150 ppm of [5-di-tert-butyl-4-hydroxyphenyl) propionate] methane was prepared.

Comparative Example 5 The conditions shown in Table 1 were used in the same manner as in Example 8 except that a co-extrusion coater was used, and that the above resin composition (R7) and resin composition (R8) were used. To give a support for an image material of Comparative Example 5 outside the present invention.

Table 3 shows the test results of the samples of Example 8 and Comparative Example 5 obtained in the same manner as described above.

[0132]

[Table 3]

Example 9 A resin composition (R1) was put into a hopper of a melt-extrusion coating machine, and a corona discharge treatment was performed on the surface of the support on which the backside resin layer was formed. With a resin thickness of 6 μm, a mirror-type cooling roll (cooling water temperature of 11 ° C.) and a linear pressure of a press roll of 40 kgf / cm, an extrusion coating speed of 3
Melt extrusion coating was performed at 30 m / min to form a lowermost resin layer. Subsequently, using a co-extrusion coater, the lower layer uses the resin composition (R1), the upper layer uses 85 parts by weight of the resin composition (R1) and 15 parts by weight of the resin composition (R2), and is sufficiently kneaded in a blender. After that, each was put into the hopper of the co-extrusion coating machine, and the resin temperature of the lower layer was 2
Co-extrusion coating was performed so that the temperature of the upper layer was 90 ° C., the resin temperature of the upper layer was 170 ° C., and the thickness of the resin of the upper layer was 7 μm. At this time, three seconds after the formation of the resin layer, liquid nitrogen gas was sprayed on the surface of the resin layer from a spray device, and three seconds later, the surface of the resin layer was subjected to corona discharge treatment by a corona discharge device. After further 3 seconds, 85 parts by weight of the resin composition (R5) and 15 parts by weight of the resin composition (R6) were sufficiently kneaded in a blender, and then charged into a hopper of a melt-extrusion coating machine. , Resin thickness 10
A melt-extrusion coating was performed to form an uppermost resin layer, and a support for an image material of the present invention of Example 9 was produced. In the case of the co-extrusion coating machine and the melt extrusion coating machine for the uppermost layer, a cooling roll having a mirror surface is used, and the conditions are the same as those for the lowermost layer. Also, the extrusion coating speed is the same.

<Evaluation> Based on the results shown in Table 1, the lower resin layer (MFR9) and the titanium dioxide pigment of 17% by weight were formed on the base paper.
Examples 1 to 3 of the present invention in which the contained upper resin layer (MFR9) was manufactured by the tandem method were the lower resin layers (MFF9).
R5) and an upper resin layer (MFR5) containing 17% by weight of a titanium dioxide pigment were compared with Comparative Examples 1 to 3 produced by a co-extrusion method, which were compared with Comparative Examples 1 to 3.
It can be seen that excellent properties can be obtained in any of the characteristics of uneven peeling and apparent glossiness. In particular, Comparative Example 1
As for Nos. To 3, it can be seen that all the characteristic values deteriorate as the extrusion coating speed increases to 260 to 400 m / min.
On the other hand, in Examples 1 to 3 of the present invention, even when the extrusion coating speed was increased, the extrusion coating speed was 40
In the case of 0 m / min, only one die lip stain is generated, and there is no hindrance in actual operation, and it can be seen how fast and suitable for long-time operation. Even when the same resin composition as in Example 3 was used for both the upper resin layer and the lower resin layer, Comparative Example 4 manufactured by the co-extrusion method showed a lower die lip stain, uneven peeling, and an apparent glossiness as compared with Example 3. It turns out that all the characteristics are inferior. Also, from the results in Table 2, it can be seen that Example 4 in which the lower resin layer was formed and then cooled by a cooling roll, and Example 5 in which the lower resin layer was subjected to a corona discharge treatment after forming the lower resin layer had more characteristics than Example 2. It can be seen that is improved. Further, it can be seen that the characteristics of Example 6 in which the corona discharge treatment was further performed after cooling with the cooling rolls after the formation of the lower resin layer were significantly improved. Further, in Example 7 in which the lower resin layer was formed and cooled by spraying with liquid nitrogen, the same good results as in Example 5 were obtained. Further, from the results shown in Table 3, the lower resin layer (MFR15) and the upper resin layer (MFR20) containing 19% by weight of titanium dioxide pigment were produced by tandem method on the base paper. Resin layer (MFR
4) and an upper resin layer (MFR7) containing 19% by weight of a titanium dioxide pigment was produced by a co-extrusion method.
Compared with Comparative Example 5 outside the present invention, in any property of die lip stain, peeling unevenness and apparent glossiness,
It can be seen that an extremely excellent product is obtained. In particular, it can be seen that the generation of die lip stains is remarkably suppressed at a high speed and in spite of the fact that the titanium dioxide pigment contains as much as 19% by weight. In addition, the sharpness of the photographic print using Example 8 was remarkably excellent. Furthermore, Example 9 in which the uppermost layer and the lowermost layer were manufactured by the tandem method and the intermediate layer was manufactured by the co-extrusion method showed slightly better results than Example 2 in the characteristics of uneven peeling and apparent glossiness. Was done.

[0135]

According to the present invention, it is possible to provide an image material and a print of the image material which are extremely excellent in appearance and have no uneven gloss, and furthermore, the generation of die lip stains during production of the support is remarkably suppressed, An excellent resin-coated paper-type image material support using paper as a substrate can be provided which has improved peelability and does not cause uneven peeling, and therefore can be produced at high speed and stably.

Claims (22)

[Claims] 1. A support for an image material, wherein a paper mainly composed of natural pulp is used as a substrate and at least one surface thereof is coated with a resin layer containing a thermoplastic resin, wherein the resin layer is the lowermost layer and the lowermost layer. The resin layer is composed of at least two layers, and the resin layer is coated by a sequential extrusion coating method in which at least a lowermost layer and at least an uppermost layer are sequentially melt-extruded and coated. Image material support. 2. The method according to claim 1, wherein at least the uppermost resin layer has a temperature of 170 ° C.
Melt-extruded at 290 ° C., and the resin layer contains 15% by weight of titanium dioxide pigment.
2. The support for an image material according to claim 1, wherein said support is contained. 3. The resin layer comprising at least two layers, wherein at least the lowermost resin layer has a temperature of 290 ° C.
3. The support according to claim 1, wherein the support is melt-extruded and coated at a temperature of from about 340 DEG C. to about 340 DEG C. 4. The resin layer comprising at least two layers, wherein the thermoplastic resin constituting each of the resin layers comprising at least the uppermost layer and the lowermost layer has a melt flow rate of 9 g / 10 minutes or more. 4. The support for an image material according to claim 1, wherein the support is an image material. 5. A quenching device wherein when a resin layer comprising at least a lowermost layer and a resin layer comprising at least an uppermost layer are successively melt-extruded and coated by a sequential extrusion coating method, the preceding resin layer is quenched. 5. The support for an image material according to claim 1, wherein after cooling, the subsequent resin layer is melt-extruded and coated. 6. The preceding resin layer is cooled by a rapid cooling device.
6. The support according to claim 5, wherein the subsequent resin layer is melt-extruded and coated within 10 seconds after cooling. 7. A method in which at least a lowermost resin layer and at least an uppermost resin layer are sequentially melt-extruded and coated by a sequential extrusion coating method, wherein the preceding resin layer is subjected to corona discharge treatment. 7. The image material support according to claim 1, wherein the subsequent resin layer is subjected to melt extrusion coating after being subjected to corona discharge treatment by the apparatus. 8. The image according to claim 7, wherein after the preceding resin layer is subjected to corona discharge treatment by a corona discharge treatment device, the subsequent resin layer is melt-extruded within 10 seconds. Support for materials. 9. The method according to claim 1, wherein the running speed of the paper substrate is at least 260 m / min.
9. The support for image materials according to 7 or 8. 10. The support according to claim 9, wherein the running speed of the paper substrate is 330 m / min or more. 11. The support according to claim 10, wherein the running speed of the paper substrate is 400 m / min or more. 12. A method for producing a support for an image material, wherein a paper mainly composed of natural pulp is used as a substrate and at least one surface thereof is coated with a resin layer containing a thermoplastic resin,
The resin layer comprises at least two layers, a lowermost layer and an uppermost layer,
The method for producing a support for an image material, wherein the resin layer is coated by a sequential extrusion coating method in which at least a lowermost layer and at least an uppermost layer are sequentially melt-extruded and coated. 13. The resin layer comprising at least two layers, wherein the resin layer comprising at least the uppermost layer has a thickness of 170
C. to 290.degree. C., which was melt-extruded and coated with 15% by weight of titanium dioxide pigment in the resin layer.
13. The method for producing a support for an image material according to claim 12, wherein said support is contained. 14. The resin layer comprising at least two layers, wherein at least the lowermost resin layer has a thickness of 290
14. The method for producing a support for an image material according to claim 12, wherein the support is melt-extruded and coated at a temperature of from 340 to 340C. 15. The resin layer comprising at least two layers, wherein the thermoplastic resin constituting each of the resin layers comprising at least the uppermost layer and the lowermost layer has a melt flow rate of 9 g / 10 minutes or more. 15. The method for producing a support for an image material according to claim 12, wherein the support is used. 16. When coating by a sequential extrusion coating method in which at least a resin layer composed of a lowermost layer and a resin layer composed of at least an uppermost layer are sequentially melt-extruded and coated, the preceding resin layer is cooled by a rapid cooling device. 16. The method for producing a support for an image material according to claim 12, wherein after cooling, the subsequent resin layer is subjected to melt extrusion coating. 17. The method according to claim 16, wherein the subsequent resin layer is melt-extruded and coated within 10 seconds after the preceding resin layer is cooled by the rapid cooling device. Method. 18. A corona discharge treatment apparatus in which when a resin layer comprising at least a lowermost layer and a resin layer comprising at least an uppermost layer are sequentially melt-extruded and coated by a sequential extrusion coating method, a preceding resin layer is subjected to corona discharge treatment. 18. The method according to claim 12, wherein the subsequent resin layer is subjected to melt extrusion coating after the corona discharge treatment. 19. The image material according to claim 18, wherein the preceding resin layer is subjected to corona discharge treatment by a corona discharge treatment device, and thereafter, the subsequent resin layer is melt-extruded and coated within 10 seconds. A method for producing a support. 20. The paper substrate according to claim 12, wherein the running speed of the paper substrate is 260 m / min or more.
20. The method for producing a support for an image material according to 5, 16, 17, 18 or 19. 21. The method according to claim 20, wherein the traveling speed of the paper substrate is 330 m / min or more. 22. The method according to claim 21, wherein the traveling speed of the paper substrate is 400 m / min or more.