JPH10260499A - Base for image material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image material which has a high glossy feel in appearance, is free from uneven glossiness and has excellent strength to stiffening and a base for a resin coated paper type image material which is capable of providing the print thereof and has a good release property from a cooling roll at production of the base. SOLUTION: The layer of 10 to 40% of the thickness over the entire part of the paper layer adjacent to the image forming side resin layer of the paper layers of the base for the resin coated paper type image material formed by coating at least one surface of base paper with a resin having film formability consists of hardwood kraft pulp having an average fiber length of 0.3 to 0.5 mm and >=60% of the thickness over the entire part of the paper layer among the other layers consists of a pulp compsn. which contains >=80 wt.% of the hardwood kraft pulp beaten to the average fiber length of 0.5 to 0.8 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a paper substrate on which one image forming layer is provided (hereinafter sometimes abbreviated as "base paper"). TECHNICAL FIELD The present invention relates to a support for an image material coated with a resin layer containing a functional resin and has a high apparent glossiness and a print thereof, particularly a silver halide photographic paper and a print thereof (silver halide photographic paper) The present invention relates to an image material support capable of providing a print (hereinafter, may be simply referred to as a photographic print). Further, the present invention can provide an image material and a print thereof, particularly a silver halide photographic printing paper and a photographic print, which have remarkably high apparent glossiness and no gloss unevenness, and which can be provided from a cooling roll at the time of manufacturing a support. The present invention relates to a support for an image material which has improved releasability and does not cause unevenness in releasability, and can be produced at high speed and in a stable manner.

[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, It is provided with an image forming layer such as a transfer type thermal transfer recording image receiving layer, a thermosensitive coloring layer, a photosensitive and thermosensitive coloring layer, and an undercoat layer, a protective layer and the like as required. In particular, the silver halide photographic constituting 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.

Heretofore, resin-coated paper-type supports in which a base paper surface for an image material support is coated with a resin capable of forming a film are well known. As a support for photographic materials for silver halide photographic materials, for example, Japanese Patent Publication No. 55-1
Japanese Patent No. 2584 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 3,50
No. 1,298 discloses a technique for a photographic material support in which both sides 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 a resin coating has a surface roughness of 7.5 microinch-AA.
There has been proposed a thermal transfer recording image receiving element having, as a support, the following resin-coated paper, 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.

First, 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 back side is the back side. Resin-coated paper for use as a support for image materials, in which at least the surface of the resin layer is sometimes referred to as a back resin layer) is coated with a resin layer containing at least a film-forming resin, particularly a resin layer containing a polyethylene resin. Using a melt extruder, the polyethylene resin composition is cast on the base paper to be cast into a film form from its slit die, coated, pressed between a pressure roll and a cooling roll, and separated from the roll after cooling. It is manufactured in a series of steps. At that time, when producing resin-coated paper for image material for glossy use, as a cooling roll, a very smooth smooth cooling roll having a mirror surface or a glossy surface or a fine rough surface described in JP-B-62-19732. Is used. Thus, the surface resin layer of the resin-coated paper is pressed into contact with a cooling roller having extremely good smoothness in a molten state, so that the surface resin layer is processed into a surface having good smoothness. Then, a material with a high glossiness should be obtained. However,
With an image material and a print thereof using a resin-coated paper actually manufactured as a support, it was not possible to obtain a material having a sufficiently high glossiness in appearance. In particular, in the case of 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.

Therefore, the present inventor has conducted various studies on the factors of the apparent glossiness of the image material and the print thereof. Although there are various factors such as an image forming method such as processing, it has been found that the apparent glossiness of the image material and its print is greatly affected by the factors of the resin-coated paper as the support. Accordingly, the present inventors further conducted various studies on the factors of the resin-coated paper that affect the apparent glossiness. As a result, the apparent glossiness of the image material and the print thereof depended on the factors of the resin layer, and the natural pulp was mainly used. Factors such as the type and properties of the base paper used as a component,
For example, the type of natural pulp, fiber length, stock slurry conditions such as paper additives to be contained in the stock slurry, paper making speed, strain press, machine calendering conditions such as machine calendering,
It has been found that it depends on various factors such as post-processing conditions such as size press and tab size press, and thus the surface roughness of the base paper. Further, as the thickness of the surface resin layer of the resin-coated paper becomes thinner, particularly when the thickness is 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 turned out to be lower. In particular, photographic materials for glossy use require a high degree of glossiness in photographic prints, and photographic materials with inferior glossiness in photographic prints are completely unsuitable for glossy use. There was a problem that the product had no commercial value.

Secondly, resin coated paper for image materials for glossy applications requires a high degree of smoothness, but in particular, if the thickness of the surface resin layer is increased when extruding and coating the molten resin on the base paper. In particular, in the case of 20 μm or more, or as the production speed of the resin-coated paper increases, the
In the case of more than minutes, the releasability of the resin-coated paper from the cooling roll is deteriorated, and horizontal step-like unevenness in the width direction called "unevenness of peeling" occurs on the resin-coated paper surface. 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,
Crater-like pores that tend to occur on the surface resin layer surface of a resin-coated paper-type photographic support by a two-layer extrusion coating method such as a co-extrusion coating method and a sequential extrusion coating method described in JP-A-1-303435. There is a description or an example of a technique for preventing, improving, and providing a photographic support excellent in smoothness without surface defects, but is insufficient for solving the above-described problems, and particularly supports resin-coated paper. It was extremely insufficient to improve and improve the apparent glossiness of the body image material and its print.

On the other hand, in order to improve the smoothness of the resin-coated paper, pulp having a specific fiber length distribution described in JP-A-58-68037 and specific pulp described in JP-A-60-69649 are disclosed. Fiber length, width, thickness pulp, softwood pulp described in JP-A-61-35442, use of specific pulp such as low-viscosity pulp described in JP-A-63-173045, JP-A-58-37642 Base paper having a Beck smoothness of a specific value or more described in
Use of a base paper having specific physical property values such as a base paper having a surface roughness of not more than a specific value described in 63-291054, JP-A-60-12639
No. 7, Japanese Patent Application Laid-Open No. 61-28
No. 4762, papermaking by a paper machine having an upper dewatering mechanism described in JP-A-63-20204, papermaking by a fourdrinier double-layer papermaking machine described in JP-A-63-204250, and wet paper described in JP-A-64-20541. Techniques such as the use of a specific papermaking method such as a tension press treatment are disclosed, but are insufficient to solve the above-mentioned problems,
In particular, it was extremely insufficient to improve and improve the apparent glossiness of an image material and a print thereof using a resin-coated paper as a support. In addition, these methods resulted in a decrease in rigidity due to a decrease in single fiber strength, a decrease in internal bond strength, a decrease in layer thickness, and the like, and only an image material which was difficult to handle and had no luxurious feeling was obtained.

[0011]

Accordingly, a first object of the present invention is to use paper containing natural pulp as a main component as a substrate.
One of the paper substrates on which the image forming layer is provided is a resin-coated paper coated with a resin layer containing a resin capable of forming a film, and the resin-coated paper is used as a support. It is an object of the present invention to provide an excellent resin-coated paper-type image material support capable of providing a material and a print thereof, particularly a silver halide photographic printing paper and a photographic print, and having a high-grade appearance without a decrease in rigidity. . A second object of the present invention is that the resin layer is coated at a production speed of 200 m / min or more, particularly 300 m / min or more, and therefore has excellent productivity and economic efficiency, and also has a high efficiency. It has improved peelability and does not cause uneven peeling, so that high-speed and stable production can be achieved, and the resin-coated paper is used as a support. An object of the present invention is to provide an excellent resin-coated paper-type image material support capable of providing the print, particularly silver halide photographic printing paper and photographic print.

[0012]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a support for a resin-coated paper type image material in which at least one surface of a base paper is coated with a film-forming resin. In the body, a layer adjacent to the polyolefin resin layer on the side where the image of the base paper is provided, and having a thickness of 10 to 40% with respect to the thickness of the entire paper layer, has an average fiber length of 0.3 to 0. A pulp composition comprising hardwood kraft pulp beaten to 5 mm, among other layers of the base paper, beaten to an average fiber length of 0.5 to 0.8 mm and containing at least 80% by weight of hardwood kraft pulp. It has been found that the object of the present invention can be attained by a support for an image material characterized in that the total thickness of the layers made of an article is 60% or more of the total thickness of the paper layer. Pulp fiber length: About pulp after beating, JAPAN
TAPPI paper pulp test method No. 52-89 Length and weight average fiber length (mm) measured according to "Paper and Pulp Fiber Length Test Method".

An object of the present invention is to provide an image forming apparatus in which the average fiber length is 0.3 to 0.3 mm adjacent to the polyolefin resin layer on the side where the image is provided.
The above-mentioned image material support, wherein the thickness of the layer made of hardwood kraft pulp beaten to 0.5 mm corresponds to 20 to 30% of the total thickness of the paper layer, and the average fiber length is 0.5 to 0.
The pulp composition beaten to 8 mm and containing at least 80% by weight of hardwood kraft pulp forms a layer having a thickness of 60% or more of the entire continuous paper layer from the paper surface on the opposite side where the image is provided. It has been found that the above-mentioned support for the image material is remarkably achieved.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the practice of the present invention, as a method of forming a multilayer base paper, a method using a multi-layer head box, a lower pulp slurry in a dewatering process on a wire.
Of the pulp slurry for the upper layer one after another, or a method of laminating each layer separately formed by a long net or a circular net, may be used. It is preferred that the layers be formed at an early stage.

At this time, the side on which the image is provided (front side)
Adjacent to the resin layer and 10 to 40% of the thickness of the entire paper layer,
The better results are obtained if the layer, preferably having a thickness of 20 to 30%, consists of hardwood kraft pulp beaten to an average fiber length of 0.3 to 0.5 mm. Preferably, the pulp other than the layer adjacent to the front side resin layer is beaten to an average fiber length of 0.5 to 0.8 mm and contains hardwood kraft pulp at 80% by weight or more,
It is important that the pulp layer of this composition accounts for at least 60% of the total thickness of the paper layer. If the fiber length of the pulp is too short in any layer other than the layer adjacent to the front side resin layer, the internal bond strength of the base paper becomes weak, and the rigidity becomes low. The effect of the present invention is limited when the pulp fiber length of the layer adjacent to the front side resin layer is too long, and becomes equal to the other layers,
On the other hand, if the fiber length of the pulp is too long, a sufficient apparent gloss cannot be obtained. When softwood pulp is used for the layer adjacent to the front resin layer, and when softwood pulp is used frequently for the other layers, the resulting glossiness is impaired. When a hardwood sulphite pulp is used for the layer adjacent to the front resin layer, and when a hardwood sulphite pulp is frequently used for the other layers, the rigidity becomes insufficient. If the thickness of the layer adjacent to the front side resin layer having a desired composition is less than 10% of the entire bite layer, the glossiness becomes insufficient, and 40%
If it exceeds, the rigidity will be insufficient. Average fiber length 0.5
If the total thickness of the pulp composition that is beaten to 0.8 mm and contains at least 80% by weight of hardwood kraft pulp is less than 60% of the thickness of the entire bite layer, depending on the type of pulp that compensates for the shortage, The stiffness may be insufficient or the gloss may be insufficient.

A layer comprising a pulp composition beaten to an average fiber length of 0.5 to 0.8 mm and containing at least 80% by weight of hardwood kraft pulp is a continuous paper layer from the opposite side of the paper surface on which an image is provided. It is desirable that the layer has a thickness of 60% or more of the whole. Further, the paper layer is beaten to a layer of hardwood kraft pulp beaten to the average fiber length of 0.3 to 0.5 mm and the average fiber length to 0.5 to 0.8 mm, and the hardwood kraft pulp is weight%. More preferably, there are only two layers of the pulp composition contained above. If on the contrary, the average fiber length is 0.5-0.8
mm, and a layer made of a pulp composition containing 80% by weight or more of hardwood kraft pulp sandwiches another layer in the middle, and when the layer is softwood pulp, the glossiness of appearance becomes disadvantageous, Sulfite pulp is disadvantageous in stiffness. Similarly, the average fiber length is 0.3 to
Between the layer of hardwood kraft pulp beaten to 0.5 mm and the layer of pulp composition beaten to the average fiber length of 0.5 to 0.8 mm and containing at least 80% by weight of hardwood kraft pulp When the layer is made of softwood pulp, it is disadvantageous in appearance glossiness, and when it is made of hardwood sulfite pulp, it is disadvantageous in rigidity.

In the present invention, the pulp has a freeness of 25.
It is preferably beaten in the range of 0 ml to 360 ml.
More preferably, beaten in the range of 0 ml to 330 ml.
If the freeness of the pulp is too low, the suitability for papermaking will be insufficient, or the rigidity of the base paper will be low. If the freeness of the pulp is too high, the formation of the base paper will tend to be poor. The freeness of pulp referred to in the present specification refers to TAPPI Standard Pulp Test Method No.
227 m-58 refers to the freeness (ml) measured in accordance with "Pulp Freeness (Freeness)".

In the present invention, the pulp can be prepared preferably by optimizing the balance between cutting and viscous beating as the pulp beating conditions for setting the fiber length and the freeness of the pulp in the preferred ranges. . In particular,
The beating conditions such as the ratio of cutting beating to viscous beating, beating time, pulp concentration, and beating power were beaten under a series of experimental conditions, and the pulp fiber length and pulp freeness of the collected pulp slurry were measured. It can be optimized by measuring.

The layers other than the layer adjacent to the resin layer on the side where the image of the base paper used in the practice of the present invention is provided are generally made of natural pulp. If necessary, synthetic fibers or synthetic pulp may be added within a range that does not impair the performance as the original base paper. As natural pulp, hardwood bleached kraft pulp is mainly used, but wood pulp of hardwood bleached sulphite pulp, softwood bleached kraft pulp, softwood bleached sulphite pulp, hardwood softwood mixed bleached sulphite pulp can also be used. . Further, in addition to non-wood pulp, soda pulp, dissolved pulp and the like, various kinds of recycled pulp (waste paper pulp) and the like can also be used in a limited manner. In the practice of the present invention, it is essential to use hardwood kraft pulp in the layer adjacent to the surface resin layer.

In the practice of the present invention, in each layer of the base paper,
Various additives can be added when preparing the stock slurry. As sizing agents, fatty acid metal salts or fatty acids, alkyl ketene dimer emulsions or epoxidized higher fatty acid amides, alkenyl or alkyl succinic anhydride emulsions described or exemplified in JP-B-62-7534, rosin derivatives, etc. 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, etc., as a fixing agent, aluminum chloride, water-soluble aluminum salts such as bansulfate, etc., as a pH regulator, caustic soda, sodium carbonate, sulfuric acid, etc., JP-A-63-204251, JP Hei 1-2
It is advantageous to incorporate the coloring pigments, coloring dyes, fluorescent whitening agents and the like described or exemplified in JP-A-66537 or the like in an appropriate combination.

In the practice of the present invention, a composition comprising various water-soluble polymers or hydrophilic colloids or latexes, an antistatic agent, and additives is placed on a base paper or a base paper by a size press or a tab size press. Alternatively, it can be impregnated or coated by coating such as blade coating or air knife coating. As a water-soluble polymer or hydrophilic colloid, starch-based polymers described or exemplified in JP-A-1-266537, polyvinyl alcohol-based polymers, gelatin-based polymers, polyacrylamide-based polymers, cellulose-based polymers, etc., as emulsions and latexes, Petroleum resin emulsion, emulsion or latex of a copolymer containing at least ethylene and acrylic acid (or methacrylic acid) as described or exemplified in JP-A-55-4027 and JP-A-1-80538, styrene -Butadiene-based,
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 include or coat 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.

In the practice of the present invention, the base paper has a thickness unevenness index Rpy in the papermaking direction defined below of 250 mV.
The paper is preferably formed so as to be as follows, more preferably 200 mV or less, and most preferably 150 mV or less. The film thickness unevenness index Rpy referred to here
Means that a sample is run between two spherical styluses, and a film thickness measuring device that measures thickness variation of the sample as an electric signal via an electronic micrometer is used, and the sensitivity range of the electronic micrometer is ± 15 μm / ±. Under the condition of 3V, the sample was scanned at a constant speed of 1.5 m / min in the papermaking direction after the zero point adjustment to measure the thickness variation of the sample in the papermaking direction, and the obtained measurement signal value was measured using an FFT analyzer. And a fast Fourier transform using a Hanning window for the time window
Power spectrum by averaging of eight integrations (unit:
mV ² ) is a value (unit: mV) obtained by summing up the power values in the frequency range of ² Hz to 25 Hz and multiplying by 2/3 and raising the value to the 乗 power.

In the embodiment of the present invention, the film thickness unevenness index Rp
As a method for producing a base paper having y of 250 mV or less, specifically, suitably beaten hardwood pulp is used in an amount of 80% by weight or more. Specifically, for example, hardwood kraft pulp beaten to a fiber length of 0.8 mm or less, preferably 0.6 mm or less is used as the whole pulp constituting the base paper. Adjacent to the front resin layer and 10 to 10
0.3 mm for a layer of hardwood kraft pulp having a thickness of 40% or more, preferably 20-30% or more
Beat to ~ 0.5 mm. The base paper is preferably formed by using a fourdrinier paper machine by using an appropriate papermaking method for the stock slurry to which the internal additive has been added so that a uniform formation can be obtained. Specifically, for example, a wet part using a fourdrinier paper machine having an appropriate upper dewatering mechanism as described or exemplified in JP-A-61-284762, which gives an appropriate turbulence to a stock slurry. As the press, a multi-stage wet press, preferably a three-stage or more wet press is performed, and a smooth paper roll is provided at the final stage of the press part, so that a uniform formation can be obtained by combining appropriate papermaking methods. And then subjected to a calendering process using a machine calender, a super calender, a heat calender, or the like, to produce a base paper having a film thickness unevenness index Rpy of 250 mV or less.

In the practice of the present invention, the base paper has a center plane average roughness in the papermaking direction at a cutoff value of 0.8 mm measured using a stylus type three-dimensional surface roughness meter on the front side of the base paper. SRa (hereinafter, the term "center plane average roughness SRa in the papermaking direction at a cut-off value of 0.8 mm measured using a stylus type three-dimensional surface roughness meter on the front side of the base paper is simply referred to as" center plane average roughness "). Is sometimes less than 1.50 μm is useful.
It is preferably 1.40 μm or less, more preferably 1.35 μm or less, particularly preferably 1.25 μm or less. Center plane average roughness SR at a cutoff value of 0.8 mm measured using a stylus type three-dimensional surface roughness meter referred to in this specification.
a is defined by Equation 1.

[0025]

(Equation 1)

In Equation 1, Wx represents the length of the sample surface area in the X-axis direction (papermaking direction), Wy represents the length of the sample surface area in the Y-axis direction (direction perpendicular to the papermaking direction), and Sa Represents the area of the sample surface area.

As a method of manufacturing a base paper having a center plane average roughness SRa of not more than 1.50 μm, which is preferably used in the practice of the present invention, specifically, a multi-stage press is used during the drying of wet paper. Further, after the base paper is formed, at least two or more series of calendar processing using a machine calendar, a super calendar, a heat calendar or the like, for example, a machine calendar processing or /
And after performing a heat machine calendering process, and further performing a machine calendering process as needed as a calendaring process of the second and subsequent series, and then performing a thermal soft calendering process described in JP-A No. 4-110939 or exemplified. A base paper having a surface average roughness SRa of 1.50 μm or less can be manufactured. Further, various water-soluble polymers or hydrophilic colloids or polymer latexes are coated in 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 1.0 g / g. m ² or more, especially 2.2 g / m ² or more is preferably contained or coated.

The density of the base paper used in the practice of the present invention is calculated from 0.80 g / cm ^{3 to} 1.15 g / c excluding ash.
preferably in the range of m ^3, but the range of 0.85g / cm ³ ~1.05g / cm ³ is more preferable, the present invention is not limited thereto. The base paper used in the practice of the present invention is not particularly limited in terms of thickness, but its basis weight is 40 g / m ^2.
To 250 g / m ² as are useful, 70g / m ² ~220g /
m ² is preferred.

The side (front side) of the support for image material on which the image forming layer of the base paper is provided is coated with a resin layer containing a resin capable of forming a film. Also, the back side of the base paper,
It is preferable to cover with a resin layer containing a resin capable of forming a film.

In the support for an image material according to the present invention, when the resin capable of forming a film in the front resin layer and the back resin layer is a thermoplastic resin, the resin composition for the front resin layer and the back resin layer is used. It is manufactured by a so-called melt extrusion coating method, in which a material is cast from a slit die into a film on a running base paper using a melt extruder and coated. Usually, using a melt extruder on a running base paper, the molten resin composition is extruded from the slit die into a film, cast and coated, and pressed between a pressure roll and a cooling roll, It is produced in a series of steps of being separated from the chill roll.

In the present invention, it is more advantageous to provide two or more resin layers on the side where an image is provided in order to improve the apparent glossiness.

An advantageous support for an image material according to the present invention has a multi-layer structure having two or more surface resin layers. Further, as a support for an image material having a multi-layer structure of two or more surface resin layers, a support manufactured by a melt extrusion coating method is preferable. In the production thereof, a so-called co-extrusion coating method in which two or more multilayer resin layers are simultaneously extrusion-coated, that is, a resin layer composed of at least the lowermost layer, and then a resin composed of at least the uppermost layer may be used. A so-called sequential extrusion coating scheme may be used in which the layers are sequentially melt-extruded coated in separate stations. Alternatively, a method of once passing through a winding resin coating line a plurality of times during processing may be employed. In the present invention, a support for an image material having a two-layered resin layer produced by a sequential extrusion coating method is particularly preferred.

In melt extrusion coating, the slit die is preferably a flat die such as a T-type die, an L-type die or a fishtail type die, and the slit opening diameter is desirably 0.1 mm to 2 mm. Further, the type of the multilayer co-extrusion die may be any type such as a feed block type, a multi-manifold type, and a multi-slot type. The temperature of the molten film is usually from 280 ° C to 340 ° C depending on the type of the resin.
In this case, a temperature difference between the resin composition for the uppermost layer and the resin composition constituting the lower resin layer may be provided. For example, by lowering the temperature of the resin composition for the uppermost layer by 5 to 10 ° C. lower than the temperature of the resin composition constituting the lower resin layer to improve the releasability of the resin layer from the cooling roll. Can be done.

The resin capable of forming a film used for the surface layer and the back layer is preferably a thermoplastic resin such as a polyolefin resin, a polycarbonate resin, a polyester resin, a polyamide resin, or a mixture thereof. Polyolefin resins and / or polyester resins are more preferred,
Polyethylene resins are particularly preferred. In addition, Tokiko Sho 60-1
It may be covered with a resin layer made of an electron beam curable resin described or exemplified in JP-A-7104.

The polyethylene resins for the front and back resin layers 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, acrylic acid ethyl ester, copolymers such as maleic anhydride or graft copolymers, so-called carboxy Modified polyethylene resin, etc., as well as polyethylene resin by high pressure radical polymerization using an autoclave type reactor, tubular type reactor, etc., polyethylene resin produced by polymerization using a metallocene polymerization catalyst, Ziegler method, Phillips method, etc. And polyethylene-based resins produced by polymerization using a metal catalyst other than metallocene, and mixtures thereof. As those polyethylene resins and mixtures, 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 (as a mixture if it is a mixture) is in the range of 0.90 to 0.97 g / cm ³ , and the MFR is 0.1 g / 10 min to 50 g / 10 min, preferably Has an MFR of 0.3
Those having a range of g / 10 minutes to 40 g / 10 minutes can be advantageously used alone or in combination.

Examples of the polyethylene resin produced by the high-pressure method, which is preferably used for the surface resin layer in the practice of the present invention, include a long-chain branch produced by a high-pressure production method using an autoclave reactor, a tubular reactor, or the like. Various types of polyethylene resins. Examples of polyethylene resins 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. A mixture of various densities, MFRs, molecular weights, and molecular weight distributions can be used, but usually the density is 0.90 to 0.90.
Those having a range of 95 g / cm ³ and a MFR of 0.1 to 50 g / 10 min, preferably a range of MFR of 0.4 to 50 g / 10 min can be used alone or in combination 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, JP-T-63-501369, JP-A-3
JP-234717, JP-A-3-234718, etc., as described or disclosed, a zirconium-based or hafnium-based metallocene and, preferably, a combination of methylaluminoxane and the like to increase the catalytic activity of a polymerization catalyst And produced by polymerization. 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. Copolymers with α-olefins such as propylene and butylene, carboxy-modified polyethylene resins and the like, and mixtures thereof.
R, molecular weight and molecular weight distribution can be used.
Density is in the range of 0.87 to 0.97 g / cm ³ , MFR is 0.05
~ 500g / 10min, preferably 0.08 ~ 300g / 10
Can be used alone or in combination 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. Various densities, MFRs, molecular weights, and molecular weight distributions can be used. However, usually the density is 0.87 ~
0.997 g / cm ³ range, MFR 0.05-500 g / 10
Min, preferably in the range of 0.08 to 300 g / 10 min, alone or as a mixture of two or more.

The polyester resin used in the practice of the present invention is a polyethylene terephthalate resin, a polybutylene terephthalate resin, a polyester biodegradable resin, a mixture thereof or a mixture thereof with a polyethylene resin. And intrinsic viscosity [η] can be used. As a specific representative example, a polyester resin manufactured by Mitsubishi Kasei Corporation (trade name: NOVAPEX)
HS004, melting point 235 ° C., density 1.33 g / cm ³ , intrinsic viscosity [η] 0.73 dl / g). Also,
A mixture of a polyester resin and a polyethylene resin can be advantageously used. For example, a mixture of a copolymerized polyethylene terephthalate resin and a copolymerized polyethylene resin grafted with maleic acid (melting point: 74 ° C.) (Mitsubishi Chemical Corporation, melting point: 224 ° C.) can be mentioned. As the polycarbonate-based resin used in the practice of the present invention, various grades can be used. As a specific representative example, a polycarbonate-based resin manufactured by Mitsubishi Kasei Corporation (trade name: NOVAREX 702)
2A, density 1.20 g / cm ³ , MFR 12-16 g / 10 min,
(Softening point: 160 ° C to 190 ° C).

The polyethylene resin for the back resin layer which is advantageously used in the practice of the present invention has an MFR of 10 g / 10 min.
40 g / 10 min, preferably 10 g / 10 min to 30 g / 10 min, 90 to 65 parts by weight of a high density polyethylene resin having a density of 0.960 g / cm ³ or more and MFR of 0.2 g / 10 min to 3g / 1
0 minutes, preferably 0.2 g / 10 minutes to 1.5 g / 10 minutes, 10 parts by weight to 35 parts by weight of a low density polyethylene resin or a medium density polyethylene resin having a density of 0.935 g / cm ³ or less. A molten and mixed compound resin composition is preferred. The molecular weight distribution of the low-density polyethylene resin or the medium-density polyethylene resin is preferably such that the fraction with a molecular weight of 500,000 or more is 10% by weight or more, and particularly preferably 12% by weight or more. If the fraction of the resin having a molecular weight of 500,000 or more is less than 10% by weight, molding processability, particularly neck-in, is undesirably large. Here, the molecular weight was measured using Waters 150-C (column: Tosoh GMH-XLHT 8 mmφ × 30 cm × 3, solvent: 1,
2,4-trichlorobenzene, temperature: 135 ° C., flow rate:
(1 ml / min) by the GPC method.

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.

When the surface resin layer is a multilayer, the uppermost resin layer (hereinafter sometimes simply referred to as the uppermost layer) and the lower resin layer (hereinafter simply referred to as the lower resin layer) may be used. ) May have the same physical properties and composition, or may be different. As the polyethylene resin preferably used for the uppermost layer and the lower resin layer, various densities, MFRs, molecular weights, molecular weight distributions and the like as described above can be used alone or in combination, and their physical properties are the same. And may be different.

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 the same as that of the polyethylene resin in the lower resin layer. MFR (when two or more kinds are contained, MFR as a mixture, hereinafter the same meaning) may be higher, lower or the same. For example, the polyethylene resin in the uppermost layer has an MFR of 5 g / 10 min to 20 g / 10 min, and the polyethylene resin in the lower resin layer has an MFR of
Can be used from 2 g / 10 min to 10 g / 10 min. On the other hand, as the polyethylene resin in the uppermost layer, the MFR is 2 g / min.
10 minutes to 10 g / 10 minutes, as the polyethylene resin in the lower resin layer, those having an MFR of 5 g / 10 minutes to 20 g / 10 minutes can be used, and those having the same MFR can be used. .

As the polyethylene resin in the uppermost layer, its density (when two or more kinds are contained, the density as a mixture, hereinafter the same meaning) is the same as that of the polyethylene resin in the lower resin layer. When the density is two or more, the density may be higher, lower, or the same as the density as a mixture. For example, a polyethylene resin in the top layer, that the density of ^{0.925g / cm 3 ~0.970g / cm 3} , as the polyethylene resin of the lower resin layer, density 0.870 g / c
m ^{3 to} 0.925 g / cm ³ , while the polyethylene resin in the uppermost layer has a density of 0.870 g / cm ³
Those ~0.925g / cm ^3, as the polyethylene resin of the lower resin layer, density 0.925g / cm ³ ~0.970g / cm ³
Can be used, and those having the same density can be used.

Further, 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 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.

The resin layer having a particularly preferred multilayer structure of the support for an image material in the present invention includes the effects of the present invention, that is, the effect of improving the apparent glossiness of an image material having the support and a print thereof, and peeling. From the viewpoint that the effect of improving the properties can be extremely remarkably exhibited, as the polyethylene resin in the uppermost layer, the density is higher than the density of the polyethylene resin in the lower resin layer by using at least one kind, Alternatively, use at least one kind of resin whose melting point is higher than the melting point of the polyethylene resin in the lower resin layer, or use at least one kind of resin whose density and melting point are higher than those of the polyethylene resin in the lower resin layer. Particularly, a resin layer having a multilayer structure is preferred.

Various additives can be contained in the front resin layer and, if necessary, in the back resin layer of the support for an image material 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, JP-B1-38291, JP-B1-382
It is preferable to include a titanium dioxide pigment described or exemplified in JP-A-92-92, JP-A-1-105245 and the like. In addition to titanium dioxide, zinc oxide, talc, white pigments such as calcium carbonate, as a release agent, stearic acid amide, fatty acid amides such as arachidic amide, as a dispersant and a releasing agent for the pigment, zinc stearate, Calcium stearate, aluminum stearate, magnesium stearate, zinc palmitate, zinc myristate,
Fatty acid metal salts such as calcium palmitate, JP-A-1-10
Hindered phenol, hindered amine, phosphorus-based, various antioxidants such as sulfur-based, described in 5245 publication, blue-based pigments and dyes such as cobalt blue, ultramarine, celian blue, phthalocyanine blue, cobalt violet, fast violet And various additives such as magenta pigments and dyes such as manganese violet, and fluorescent whitening agents and ultraviolet absorbers described or exemplified in JP-A-2-254440. These additives are preferably contained as a resin masterbatch or compound. In addition, from the viewpoint of the sharpness or whiteness of the print or the effective improvement of the heat resistance, light resistance or release property of the image material support, a white pigment such as titanium oxide, a fluorescent whitening agent, a coloring pigment or coloring. It is preferred that the dye or other additives such as an antioxidant, an ultraviolet absorber or a release agent be contained in the uppermost layer at a higher concentration than in the lower resin layer.

In the practice of the present invention, it is preferable to perform an activation treatment such as a corona discharge treatment or a flame treatment on the base paper before coating the front and back resin compositions 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. May be coated with a multilayer structure. The surface resin layer surface of the image material support has a glossy surface.
It can be processed to a fine rough surface, matte surface or silk surface described in JP-19732-A, and the back resin layer is usually preferably processed to a matte surface.

The total 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 4 μm.
A range of 0 μm is particularly preferred. In the present invention,
When the surface resin layer has a multilayer structure, the thickness of the lowermost resin layer is 25% or more of the total resin layer thickness on the front side from the viewpoint of the effect of improving the apparent glossiness of the image material and its print. Is preferable, and a thickness of 39% or more is more preferable.
A thickness of 0% 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 where curl balance is obtained.
A range of 0 μm is useful, but preferably 12-60 μm
Range.

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 and a flame treatment. 92740
An undercoat layer as described or exemplified in JP-A Nos. Hei. 1-102551 and 1-166035 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 done. Further, the back coat layer, JP-B-52-18020, JP-B-57-9059, JP-B-57-53940, JP-B-58-56859, JP-A-59-56859
-214849, JP-A-58-184144 and the like or inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latexes, curing agents, pigments, surfactants and the like may be appropriately combined and contained. I can do it.

The support for the 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. , For silver salt diffusion transfer method negative and positive, and for 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 layer. Further, a photographic component layer for silver salt diffusion transfer method can be provided. As binders 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, various additives can be contained in the above-mentioned photographic constituent layer. For example, as sensitizing dyes, cyanine dyes, merocyanine dyes, etc., as chemical sensitizers, water-soluble gold compounds, sulfur compounds, etc., as antifoggants or stabilizers, hydroxy-triazolopyrimidine compounds, mercapto-heterocyclic compounds, etc. , As a hardening agent, formalin, vinyl sulfone compound, aziridine compound,
Active halogen compounds, coating aids such as alkylbenzene sulfonates, sulfosuccinates, etc., stain inhibitors, dialkyl hydroquinone compounds, etc., fluorescent brighteners, sharpness improving dyes, antistatic agents, pH adjusters, etc. A fogging agent and a water-soluble iridium compound, a water-soluble rhodium compound, and the like can be added in an appropriate combination at the time of forming and dispersing 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. I can do it.

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. Synthetic resins 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. Resin having urethane bond such as polyurethane resin, resin having amide bond such as polyamide resin, resin having urea bond such as urea resin, other polycaprolactam resin, styrene resin, polyvinyl chloride resin, 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, etc. may be added in addition to the above 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 preferably 0.1 to 20% by weight in the image receiving layer. As the pigment, silica, calcium carbonate,
Extenders such as titanium oxide and zinc oxide are preferred. Also,
The thickness of the image receiving layer is preferably 0.5 to 20 μm,
-10 μm is more preferred.

The support for an image material according to 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, gelatin derivatives, and various gelatins such as phthalic acid, maleic acid, and gelatin reacted with an anhydride of a dibasic acid such as fumaric acid. , Ordinary polyvinyl alcohol of various saponification degrees,
Carboxy-modified, cationic-modified and amphoteric polyvinyl alcohol 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
Maleic acid ester copolymer, vinyl acetate / acrylic acid ester copolymer, vinyl acetate polymer latex such as 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, etc., or functional group-containing monomer such as carboxyl group of these various polymers Functional group-modified polymer latex, melamine resin, aqueous adhesive such as thermosetting synthetic resin such as urea resin and polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride / vinyl acetate copolymer, polyvinyl butyral, Synthetic resin-based adhesive such as alkyd resin, Japanese Patent Publication 3-24906 No., JP-A-3-281383,
Inorganic binders such as alumina sol, silica sol and the like described or exemplified in Japanese Patent Application No. 4-407725 can be used, and these 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, JP-B-47-9303
Silane coupling agents such as γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, such as fluorinated surfactants described in US Pat. No. 3,589,906 and the like; As a polymer hardener, an active halogen compound, a vinyl sulfone compound, an aziridine compound, an epoxy compound,
Acryloyl compounds, hardening agents such as isocyanate compounds, as preservatives, P-hydroxybenzoic acid ester compounds described or exemplified in JP-A-1-102551, benzisothiazolone compounds, isothiazolone compounds, and the like, JP-A-63-204251 Publication, JP-A 1-266537 JP or illustrated or exemplified color pigments, coloring dyes, fluorescent whitening agents,
Sodium hydroxymethanesulfonate and sodium P-toluenesulfinate as yellowing inhibitors; benzotriazole compounds having a hydroxy-dialkylphenyl group at the 2-position as ultraviolet absorbers; JP-A No. 105337/1992 discloses fine or organic particles such as starch granules, barium sulfate and silicon dioxide having a particle size of 0.2 to 5 μm, such as polyhindered phenol compounds described or exemplified in JP-B-105245. Organopolysiloxane compounds described or exemplified in gazettes and the like, p
As the H regulator, various additives such as octyl alcohol, silicon-based antifoaming agents such as caustic soda, sodium carbonate, sulfuric acid, hydrochloric acid, phosphoric acid, and citric acid can be appropriately combined and contained.

[0057]

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.

Examples 1 to 7 and Comparative Examples 1 to 8 Hardwood bleached kraft pulp was adjusted to a concentration of 4% by weight on a dry basis and beaten to an average pulp fiber length of 0.4 mm and a Canadian standard freeness of 350 ml. Pulp for the upper layer of three-layer papermaking (layer adjacent to the resin on the side where the image is provided). Similarly, bleached hardwood bleached sulphite pulp was beaten to an average fiber length of 0.8 mm and a Canadian standard freeness of 350 ml to obtain pulp for the middle layer. A pulp mixture composed of 90% by weight of hardwood kraft pulp and 10% by weight of hardwood sulphite pulp was beaten to an average fiber length of 0.6 mm and a Canadian standard freeness of 350 ml to obtain a lower layer pulp. After beating, each pulp was beaten, 100 parts by weight of pulp, 3 parts by weight of cationized starch, 0.2 parts by weight of anionized polyacrylamide, 0.4 parts by weight of alkyl ketene dimer emulsion (as ketene dimer), polyamide 0.4 parts by weight of epichlorohydrin resin and an appropriate amount of an optical brightener,
A blue dye and a red dye were added to prepare a stock slurry. After that, the stock slurry showed the upper, middle and lower layer balance in Table 1.
The paper is formed on a fourdrinier paper machine running at 200 m / min in three layers (partially two layers) with appropriate turbulence.
After performing a three-stage wet press in which the linear pressure was adjusted in the range of 0 kgf / cm, the wet press was processed with a smoothing roll, and in the subsequent drying part, a two-stage tension in which the linear pressure was adjusted in the range of 30 to 70 kgf / cm. After pressing, it was dried. Thereafter, during the drying, 25 g / size press solution composed of 4 parts by weight of carboxy-modified polyvinyl alcohol, 0.05 parts by weight of a fluorescent whitening agent, 0.002 parts by weight of a blue dye, 4 parts by weight of sodium chloride and 92 parts by weight of water. m ² size press, dried so that the finally obtained base paper water content is 8% by weight in absolute dry water content, machine calendered at a linear pressure of 70 kgf / cm, and a basis weight of 170 g / m ² , Density is 1.04 g / cm ³ , uneven film thickness R
A base paper for an image material support having a py value shown in Table 1 was produced.

Separately, an image material base paper was manufactured in the same manner as in Example 6 except that the upper and lower paper amount slurries used in Example 6 were mixed at the same ratio, and used as a base paper for Comparative Example 8.

Next, after the base paper surface (back surface) opposite to the side on which the image forming layer is provided is subjected to corona discharge treatment, the following resin composition (R1) is applied to the back surface at a resin temperature of 315 ° C. and a resin thickness of 20 μm. In addition, melt extrusion coating was performed at a running speed of the base paper of 200 m / min. At this time, as a cooling roll, the center surface average roughness SRa of the back layer surface after applying the following back layer was used.
Used had a roughness of 1.15 μm. The cooling roll used was a cooling roll roughened by a liquid honing method and operated at a cooling water temperature of 12 ° C.

(Resin composition R1) 70 parts by weight of a high-density polyethylene resin (0.967 g / cm ³ , MFR = 15 g / 10 min) and a low-density polyethylene resin (density 0.924 g / cm ³ ,
(MFR = 0.6 g / 10 min.) 30 parts by weight using a melt extruder to melt and mix in advance, and used as pellets.

Subsequently, after the surface of the base paper was subjected to a corona discharge treatment, a tubular low-density polyethylene resin [density 0.918 g / cm ³ , MFR = 8.
5 g / 10 min, melting point: 108 ° C., hereinafter abbreviated as low-density polyethylene resin (R2)] 47.5% by weight, hydrous aluminum hydroxide (0.5% as Al ₂ O ₃ minutes with respect to titanium dioxide)
0% by weight), anatase type titanium dioxide pigment 50% by weight, zinc stearate 2.5% by weight and an antioxidant, tetrakis [methylene-3 (3,5-di-tert.)
-Butyl-4-hydroxyphenyl) propionate]
17 parts by weight of a titanium dioxide pigment masterbatch consisting of 150 ppm of methane [hereinafter abbreviated as masterbatch (MB-1)], 46.25 parts by weight of a low-density polyethylene resin (R2)
%, The above titanium dioxide pigment 50% by weight, turquoise (manufactured by Daiichi Kasei Kogyo Co., Ltd., # 2000) 1.25% by weight, zinc stearate 2.5% by weight, and the above antioxidant 150ppm, a titanium dioxide pigment masterbatch [Hereinafter abbreviated as masterbatch (MB-2)] 8 parts by weight, autoclave low-density polyethylene resin [density 0.920 g / cm ³ , MFR =
4.5 g / 10 min, melting point 109 ° C., hereinafter abbreviated as low density polyethylene resin (R3)] 57.6 parts by weight and Philips high density polyethylene resin [density 0.967 g / cm ³ , M
FR = 7.0 g / 10 min, melting point: 130 ° C., hereinafter abbreviated as high-density polyethylene resin (R4)] A resin composition consisting of 17.4 parts by weight is run at a resin temperature of 315 ° C. to a thickness of 28 μm on a base paper. Using a melt extruder at a speed of 200 m / min, the coating was melt-extruded and coated at a linear pressure of 40 kgf / cm between the mirrored cooling roll and the press roll. The melt extrusion coating of the front and back polyethylene resins was performed by a so-called tandem method in which melt extrusion coating was performed sequentially. At that time, the surface of the resin layer containing the titanium dioxide pigment of the resin-coated paper was processed into a glossy surface.

Further, after the front and back resin layers are processed and wound up, the back resin layer surface of the resin-coated paper is subjected to a corona discharge treatment.
The following coating solution for the back layer was applied on-machine. As dry weight, colloidal silica: styrene latex =
1: 1 and 0.21 g of a coating liquid for a back layer containing 0.021 g / m ² of sodium polystyrene sulfonate and an appropriate amount of a coating aid in terms of latex (calculated as solid weight).
/ m ² was applied.

After applying the back layer and before winding the resin-coated paper, the front resin surface is subjected to a corona discharge treatment to obtain 1.2 g of lime-treated gelatin and low molecular weight gelatin (manufactured by Nitta Gelatin Co., Ltd.). P-3226), 0.3 g of a 10% by weight methanol solution of butyl parahydroxybenzoate and 0.45 g of a 5% by weight mixture of methanol and water of sulfosuccinic acid-2-ethylhexyl ester salt. The undercoating solution prepared to 100 g was coated with gelatin at an amount of 0.1 g.
On-machine coating was carried out uniformly to obtain a support for image material of 0.6 g / m ² .

The following method was used to evaluate the apparent glossiness of a photographic print having a support for an image material.

A blue-sensitive emulsion layer containing a yellow-color-forming coupler, an intermediate layer containing a color-blinding agent, a green-sensitive emulsion layer containing a magenta-color-forming coupler, and ultraviolet An ultraviolet absorbing layer containing an absorber, a red-sensitive emulsion layer containing a cyan coloring coupler, and a protective layer were coated with 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 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. . Separately, baking samples of white solid (unexposed) and black solid (black coloring) were 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) → bleach-fix (45 seconds) → stable (90 seconds) → drying.

With respect to the obtained group photograph, white solid and black solid photographic prints, the glossiness of the photographic prints was visually evaluated comprehensively by 10 monitors.

The evaluation criteria for the apparent glossiness of a photographic print are as follows. A: Very high glossiness in appearance. 〜 To ○: Appearance of glossiness is considerably high. : The glossiness in appearance is much higher. 〜 To □: High glossiness in appearance. □: The glossiness is slightly low in appearance. Δ: The glossiness is low in appearance, and there is a problem in practical use. X: The apparent glossiness is extremely low.

As a practical evaluation of stiffness, waist strength was evaluated. The evaluation method of the waist strength of the image material is 13 cm.
A color photograph print of × 18 cm was shaken up and down with the end of the color photograph print by 10 monitors, and the waist strength by the feeling of touch was evaluated. The evaluation criteria are as follows. A: The waist is extremely strong. ：: The waist is strong. □: Waist is slightly weak, but practically possible. X: The waist is weak, and there is a practical problem to some extent.

Table 1 shows the obtained results.

[0072]

[Table 1]

From the results in Table 1, it is found that Comparative Examples 1 and 2 in which the upper layer has a small amount of short fiber pulp have insufficient glossiness. On the other hand, Comparative Examples 3 to 7 in which the thickness of the lower layer is small have insufficient waist strength. On the other hand, it can be seen that Examples 1 to 7 of the present invention have a good balance between glossiness and waist strength. Comparative Example 8 in which the upper and lower pulp of Example 6 were mixed and made into a single layer was insufficient in glossiness.

Examples 8 to 19 Example 5 was carried out in the same manner as in Example 5 except that the average fiber length of the upper layer pulp and the thickness of the upper layer were as shown in Table 2. Table 2 shows the obtained results.

[0075]

[Table 2]

From Table 2, it can be seen that the shorter the average fiber length, the higher the glossiness, and the longer the average fiber length, the stronger the waist. It can be seen that the thicker the upper layer, the higher the glossiness, and the thinner, the stronger the waist.
It can be seen that, when the thickness of the upper layer is in the range of 20 to 30%, the balance between glossiness and stiffness is particularly good in the range of the present invention.

Examples 20 to 31 Example 5 was carried out in the same manner as in Example 5, except that the average fiber length of the lower layer pulp and the thickness of the lower layer were as shown in Table 3. Table 3 shows the obtained results.

[0078]

[Table 3]

From Table 3, it can be seen that the lower the fiber length of the lower layer, the more advantageous in the stiffness, and that there is no particular problem with the glossiness in this range.

Examples 32 to 34 and Comparative Examples 9 to 18 Table 4 shows the average fiber length of the upper and lower pulp, the proportion of the hardwood kraft pulp in the lower pulp, and the type of the remaining pulp in the upper and lower layers in Example 6. The procedure was performed in the same manner as in Example 6 except that the procedure was as follows. Table 4 shows the obtained results.

[0081]

[Table 4]

In Table 4, LK represents hardwood kraft pulp, LS represents hardwood sulphite pulp, NK represents softwood kraft pulp, and NS represents softwood sulphite pulp. Residual P represents pulp other than lower layer pulp medium hardwood kraft pulp.

As shown in Table 4, Comparative Example 9 in which the upper layer has a long average fiber length, Comparative Examples 15 and 16 in which the upper layer is softwood pulp have insufficient glossiness, and Comparative Example 1 in which the upper layer has a short average fiber length.
0, Comparative Example 14 in which the upper layer pulp is hardwood sulfite pulp has insufficient stiffness. On the other hand, Comparative Example 11 in which the ratio of the hardwood kraft pulp in the lower layer is low, Comparative Example 12 in which the average fiber length of the lower layer is short have insufficient waist strength, and Comparative Example 13 in which the average fiber length of the lower layer is too long is gloss. In Comparative Examples 17 and 18, in which the proportion of the hardwood kraft pulp in the lower layer was low but the other pulp was softwood pulp, the waist strength was good but the glossiness was insufficient. I understand. In contrast, Examples 32 and 3 of the present invention
It can be seen that Nos. 3 and 34 satisfied both the glossiness and the strength of the waist.

Examples 35 and 36 The same procedures as in Example 6 were carried out except that the middle layer of Example 6 was transferred while the lower layer was equally divided, and four layers of paper were made. Further, Example 36 was carried out in the same manner as in Example 4 except that the middle layer and the lower layer in Example 4 were mixed in the same ratio to form a lower layer, and two layers of paper were made. Table 5 shows the obtained results.

[0085]

[Table 5]

From Table 5, it is found that Example 35, in which the average fiber length is 0.6 mm and the layer containing 90% by weight of the hardwood kraft pulp is not continuously 60% in thickness, is disadvantageous in the strength of the waist. Example having an upper layer composed of hardwood kraft pulp having an average fiber length of 0.4 mm and a lower layer composed of a pulp composition containing an average fiber length of 0.6 mm and a hardwood kraft pulp of not less than 80% by weight. 36 shows that the pulp composition is the same as that of Example 4 but is advantageous in terms of stiffness.

Examples 37 and 38 In Example 36, the surface of the base paper was subjected to corona discharge treatment.
As a surface resin layer (2), the same resin composition as the surface resin layer (1) having a thickness of 14 μm as a lower resin layer on the surface, and a surface resin layer (1) having a thickness of 14 μm as an upper resin layer. The same resin composition was run at a resin temperature of 315 ° C. and a running speed of
m / min, using a two-layer co-extrusion machine, except that the two layers are simultaneously extruded and coated at a linear pressure of 40 kgf / cm between the mirror-surface cooling roll and the press roll, in the same manner as when coating the surface resin layer (1). Example 37 was carried out in the same manner except that resin coating was performed.

Similarly, after the surface of the base paper is subjected to a corona discharge treatment, the same resin composition as the surface resin layer (1) having a thickness of 14 μm is formed as a surface resin layer (3) and a lower resin layer on the surface. As the upper resin layer, the same resin composition as that of the surface resin layer (1) having a thickness of 14 μm was used.
At a speed of 00 m / min, the lower layer and then the upper layer were sequentially extruded at separate stations using a melt extruder at a linear pressure of 40 kgf / cm of the mirror surface cooling roll and the press roll except for the surface resin layer (1 Example 38, except that resin coating was performed in the same manner as in the case of coating.
And

As a method for evaluating the releasability of the surface resin layer from the cooling roll when each image material paper support is manufactured, the overall irregularity of peeling during the manufacture of the support is visually observed. The surface state of the front side of the obtained image material support was observed with oblique light, the degree of occurrence of peeling unevenness was visually determined, and a 10-grade evaluation was performed. The evaluation criteria (the larger the grade value, the better the releasability, and the smaller the grade value, the worse the releasability) are as follows.

Grades 10 to 9: Peeling from the chill roll has no irregularities, no or little uneven peeling, and very good peeling properties. Grade 8-7: Peeling from the chill roll has almost no irregularities, unevenness of peeling is slight, and peelability is good. Grade 6 to 5: Peeling from the cooling rolls shows slight irregularities, and there is some occurrence of peeling unevenness, but it is practically acceptable. Grade 4-1: Peeling from the cooling roll shows irregularities, and there are many occurrences of uneven peeling, which is a practical problem.

Table 6 shows the obtained results.

[0092]

[Table 6]

From the results shown in Table 6, when the resin layer has two layers,
Further, it can be seen that when it is a two-layered film by sequential extrusion, both the releasability and glossiness are excellent.

Examples 39 to 42 In Example 38, when the surface resin layer (3) was successively melt-extruded and coated, the resin temperature of the resin composition for the upper layer and the lower layer was changed to the resin temperature shown in Table 7 Other than that, it carried out similarly to Example 38.

Table 7 shows the obtained results.

[0096]

[Table 7]

From the results shown in Table 7, in the present invention, from the viewpoint of the effect of improving the releasability, when the resin composition for the surface resin layer having a multilayer structure is subjected to melt extrusion coating, the resin composition for the uppermost layer is coated. It is well understood that the temperature is preferably lower than the temperature of the resin composition constituting the lower resin layer.

Examples 43 to 47 The same procedures as in Example 38 were carried out except that the coating thickness of the upper and lower layers of the surface resin layer (3) was changed to the coating thickness shown in Table 8 below. .

Table 8 shows the obtained results.

[0100]

[Table 8]

From the results shown in Table 8, among the image material supports of the present invention having a multilayered surface resin layer, at least from the lowermost layer in view of the effect of improving the apparent glossiness and peelability of photographic prints. It can be clearly seen that the thickness of the resulting resin layer is preferably 25% or more of the total resin layer thickness, more preferably 39% or more, and particularly preferably 50% or more.

Examples 48 to 54 In place of the resin composition for the upper layer or the lower layer of the surface resin layer used in Example 38, the following resin compositions (38 UA) to
(38UD) and (38LE) to (38LG) are shown in Table 9.
Example 38 was carried out in the same manner as in Example 38 except that the combination was used.

(Resin composition for upper layer): (38 UA)
(38 UD) Resin composition (38 UA): 17 parts by weight of master batch (MB-1) used in Example 38, 8 parts by weight of master batch (MB-2) used in Example 38, and used in Example 38 A resin composition comprising 75 parts by weight of a low density polyethylene resin (R3).

Resin composition (38 UB): The same resin composition for the upper layer as used in Example 38 (high-density polyethylene resin content relative to all resin components in the upper layer, 20.1% by weight)
%).

Resin composition (38UC): 17 parts by weight of master batch (MB-1) and master batch (MB-2)
A resin composition comprising 8 parts by weight, 40.2 parts by weight of a low-density polyethylene resin (R3) and 34.8 parts by weight of a high-density polyethylene resin (R4) (corresponding to 40.1% by weight based on all resin components in the upper layer). .

Resin composition (38UD): 21 parts by weight of master batch (MB-1) and master batch (MB-2)
A resin composition comprising 9 parts by weight, 53.1 parts by weight of a low-density polyethylene resin (R3) and 16.9 parts by weight of a high-density polyethylene resin (R4) (corresponding to 20.1% by weight based on all resin components in the upper layer). .

(Resin composition for lower layer): (38LE) to
(38LG) Resin composition (38LE): The same resin composition for lower layer as used in Example 38.

Resin composition (38LF): density 0.924 g
An autoclave low-density polyethylene resin having a melting point of 111 ° C./cm ³ , MFR of 4.5 g / 10 minutes.

Resin composition (38LG): density 0.924 g
/ cm ³ , MFR 3.0 g / 10 min, tubular method low density polyethylene resin having a melting point of 111 ° C.

Table 9 shows the obtained results.

[0111]

[Table 9]

From the results shown in Table 9, among the image material supports of the present invention in which the surface resin layer of the present invention was formed into a multilayer structure by sequential extrusion, it was found to be the most effective in improving the glossiness and peelability of the photographic print. It is well understood that it is preferable to include at least one resin having a higher density or melting point in the upper layer than the resin in the lower resin layer. Also, even if the content of additives such as titanium dioxide pigment, coloring pigment, release agent and antioxidant in the resin layer below the uppermost layer is lower than the content of additives in the uppermost layer, It can be clearly seen that there is no problem with the effect of the present invention, and that it is economically advantageous.

Examples 55 to 61 Instead of the resin composition for the upper layer or the lower layer of the surface resin layer used in Example 37, the following resin compositions (37 UA) to
(37UD) and (37LE) to (37LG) are shown in Table 1.
The same operation as in Example 37 was performed, except that 0 was used. Note that (37UA) to (37UD) and (37L)
E) to (37LG) are (38UA) to (38UD), respectively.
And (38LE) to (38LG) are substantially the same except that the sequential extrusion is changed to coextrusion.

Table 10 shows the obtained results.

[0115]

[Table 10]

From the results in Table 10, it can be seen that even in the case where the surface resin layer of the present invention is co-extruded in the image material support having a multilayer structure, the apparent glossiness and peelability of the photographic print can be seen. From the viewpoint of the improvement effect, it is well understood that it is preferable to include at least one resin having a higher density or melting point in the uppermost layer than the resin in the lower resin layer. Further, even if the content ratio of the titanium dioxide pigment, the coloring pigment, the release agent, the antioxidant and the like in the resin layer below the uppermost layer is lower than the content ratio of the additive in the uppermost layer, the present invention It can be clearly seen that there is no problem in the effect and that it is economically advantageous.

Examples 62 to 64 In place of the resin composition for the upper layer and the resin layer for the lower layer used in Example 37, a resin composition (37 UD) was used as the resin composition for the upper layer. The procedure was performed in the same manner as in Example 37, except that the resin composition (37LF) was used as the resin composition for the lower layer, and the running speed of the base paper was set to the running speed shown in Table 11.

Table 11 shows the obtained results.

Examples 65 to 67 The same operations as in Example 52 were carried out except that the running speed of the base paper was changed to the running speeds shown in Table 11.

Table 11 shows the obtained results.

[0121]

[Table 11]

The results shown in Table 11, ie, Example 62 and Example 6
5 (each with a running speed of 200 m / min for the base paper), Examples 63 and 66 (each with a running speed of 250 m / min for the base paper) and Examples 64 and 66 (with a running speed of 300 m / min for each of the base paper) From the comparison of the results, the higher the traveling speed of the base paper (that is, the production speed of the support for the image material), that is, the traveling speed of the base paper is 200 m / min or more, further 250 m / min or more, In particular, when the speed is 300 m / min or more, the surface resin layer has a multilayer structure by the sequential melt extrusion coating method among the image material supports in the present invention, from the viewpoint of improving the apparent glossiness and peeling unevenness of the photographic print. It can be clearly seen that the reduced support for image materials is particularly preferred. Further, the image material support is a particularly excellent image material support that can provide an image material having a high apparent glossiness and a print thereof, does not cause peeling unevenness, and can be rapidly and stably produced. I understand well.

Example 68 An ink jet recording material was prepared by applying the following ink image receiving layer on the image material support of Example 38 instead of the multilayer silver halide color photographic component layer. As a result, the inkjet recording material has a high apparent gloss and
There was no uneven gloss, and the support for the image material was excellent.

The ink image receiving layer was composed of 30 g of a 10% by weight aqueous solution of alkali-treated gelatin having a molecular weight of 70,000, sodium carboxymethyl rose (etherification degree: 0.7 to 0.8,
37.5 g of an 8 wt% aqueous solution of a 2 wt% aqueous solution having a viscosity of 5 cp or less as measured by a B-type viscometer, 0.3 g of a 5 wt% methanol solution of an epoxy compound (NER-010 manufactured by Nagase & Co., Ltd.), It was formed by applying a coating solution consisting of 0.5 g of a 5% by weight mixed solution of acid-2-ethylhexyl ester salt of methanol and water and 31.7 g of pure water at a solid content of 7 g / cm ² for 7 minutes.

[0125]

According to the present invention, the apparent glossiness is high.
Paper that can provide an image material and a print thereof having no gloss unevenness and excellent in stiffness, and that has good releasability from a cooling roll at the time of manufacturing a support, and therefore can be produced at high speed and stably. An excellent resin-coated paper-type support for an image material serving as a substrate can be provided.

Claims (6)

[Claims] 1. A resin-coated paper-type image material support in which at least one surface of a base paper is coated with a polyolefin resin, wherein the paper is adjacent to a polyolefin resin layer on the side where an image of the base paper is provided. 10 to 40 with respect to the thickness of the entire layer
% Of the hardwood kraft pulp beaten to an average fiber length of 0.3 to 0.5 mm, and the other layers of the base paper have an average fiber length of 0.5 to 0.8 mm. A support for image materials, characterized in that the total thickness of the layer formed of the pulp composition which is beaten and contains at least 80% by weight of hardwood kraft pulp is at least 60% of the total thickness of the paper layer. Pulp fiber length: About pulp after beating, JAPAN
TAPPI paper pulp test method No. 52-89 Length and weight average fiber length (mm) measured according to "Paper and Pulp Fiber Length Test Method". 2. The thickness of the layer of hardwood kraft pulp beaten to an average fiber length of 0.3 to 0.5 mm adjacent to the polyolefin resin layer on the side where the image is provided is 20 to the total thickness of the paper layer. 2. The support for image materials according to claim 1, which corresponds to about 30%. 3. A pulp composition beaten to an average fiber length of 0.5 to 0.8 mm and containing at least 80% by weight of hardwood kraft pulp, and the whole paper layer continuous from the paper surface on the opposite side where an image is provided. 3. The support for an image material according to claim 1, wherein the support has a thickness of at least 60% of the thickness of the support. 4. The paper layer has an average fiber length of 0.3 to 0.5 mm.
A hardwood kraft pulp that has been beaten into a pulp composition and a pulp composition that has been beaten to an average fiber length of 0.5 to 0.8 mm and contains at least 80% by weight of hardwood kraft pulp. Item 14. The support for an image material according to Item 1 or 2. 5. The support for an image material according to claim 1, wherein the polyolefin resin layer on the side on which the image is provided comprises a plurality of layers. 6. The support for an image material according to claim 5, wherein the resin layer has a two-layer constitution by successive extrusion coating.