JP3328396B2 - Polyolefin resin coated paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper made of natural pulp as a main component, and one of the paper substrates (hereinafter referred to as "base paper") coated with a polyolefin resin. The generation of pit-shaped pores was significantly suppressed,
The present invention relates to a polyolefin resin-coated paper having no surface defects and excellent in smoothness, and particularly to a polyolefin resin-coated paper having no surface defects and excellent in smoothness for use as an image material.

[0002]

2. Description of the Related Art Hitherto, a polyolefin resin-coated paper using a paper mainly composed of natural pulp as a substrate, particularly a polyolefin resin-coated paper for use as an image material, is well known. For example, Japanese Patent Publication No. 55-12584 discloses a technique for a photographic support in which a base paper is coated with a resin having film-form performance, preferably a polyolefin resin. U.S. Pat. No. 3,501,298 discloses a technique for a photographic support in which both sides of a base paper are coated with a polyolefin resin. In addition, since the rapid photographic development processing method of silver halide photographic light-sensitive materials was applied, a photographic support in which both sides of a base paper were coated with a polyethylene resin,
It is mainly used for photographic printing paper, and a titanium dioxide pigment is usually contained in the resin layer on one image forming side as needed, in order to impart sharpness.

[0003] Also, 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, in particular, a polyethylene resin-coated paper in which the surface of a base paper is coated with a polyethylene resin. U.S. Pat. No. 4,999,335 discloses a blend of a polyethylene resin and a polypropylene resin, wherein the weight ratio of polyethylene resin: polypropylene resin is 4: 1 to 1: 1.
There has been proposed a thermal transfer recording image-receiving element having, as a support, a resin-coated paper obtained by coating a base paper with a 1:99 resin.
Further, Japanese Patent Application Laid-Open No. 63-307979 discloses a technique relating to an ink jet recording sheet having a resin-coated paper as a support.

[0004] However, resin-coated paper in which at least one surface of a base paper mainly composed of natural pulp is coated with a polyolefin resin, particularly polyolefin resin-coated paper as a support for image materials, is still important in several respects. Had a serious problem.

[0005] First, polyolefin resin-coated paper is coated on a normally running base paper by casting the polyolefin resin from a slit die into a film shape using a melt extruder, and applying a pressure roll to a cooling roll. It is manufactured by a series of steps in which it is pressed against a roll and peeled off from the roll after cooling. However, in the conventional polyolefin resin-coated paper, the higher the production speed, the worse the releasability of the polyolefin resin-coated paper from the cooling roll becomes, and the widthwise horizontal step called peeling unevenness on the resin-coated paper surface. Is the occurrence of unevenness. When this peeling unevenness occurs, the smoothness of the polyolefin resin-coated paper is remarkably deteriorated, and it is completely unsuitable as a polyolefin resin-coated paper that requires no surface defects and requires excellent smoothness, particularly a polyolefin resin-coated paper for use as an image material. There was a problem that it would be appropriate and had no commercial value.

Second, in the conventional polyolefin resin-coated paper, the higher the production speed and the thinner the coating thickness of the polyolefin resin, the more the satin finish is formed on the coated resin surface of the polyolefin resin-coated paper. Pit-shaped fine pores are generated. When the pit-like pores are generated, the smoothness of the polyolefin resin-coated paper is remarkably deteriorated, and polyolefin resin-coated paper which requires excellent smoothness without surface defects, particularly, polyolefin resin-coated paper for use in image materials. In addition, there is a problem that the product is completely inappropriate and has no commercial value.

The above-mentioned polyolefin resin-coated paper,
There are several technical proposals for eliminating and improving various problems and other disadvantages of polyolefin resin-coated paper, particularly for use in imaging materials. In order to improve the releasability during the production of polyolefin resin-coated paper, it has been proposed to include various release agents in the polyolefin resin.
For example, specific fatty acid amides described in JP-A-60-176036, polyalkylene glycol compounds described in JP-A-63-30841, fluorine-containing polymers described in JP-A-64-9444, JP-A-4-143748 Various release agents, such as α-olefin-modified silicones described in Japanese Patent Application Laid-Open No. H10-260, have been proposed. However, even when these release agents are contained in the polyolefin resin, the effect of improving the releasability is extremely insufficient. In particular, at a production speed of 180 m / min or more, there is little or no effect. The problem is that the adhesion between the base paper and the polyolefin resin layer is deteriorated, or the adhesion between the coating layer applied on the polyolefin resin-coated paper, particularly the image forming layer and the polyolefin resin layer, is deteriorated. A point has occurred.

Another attempt to improve the releasability during the production of polyolefin resin-coated paper is disclosed in JP-B-62-19732.
Use of micro-roughened cooling rolls described in Japanese Patent Publication
The use of a cooling roll embedded with a fluororesin described in 1-24292 Publication, and further, the melting peak described in JP-A-1-129249 is 110 ° C or higher, and the melt index is 5 to 20 g / 10. A technique has been proposed for the use of low density polyethylene resin. However,
Even if these cooling rolls or resins are used, the effect of improving the releasability of the polyolefin resin-coated paper is insufficient, especially at a production speed of 180 m / min or more, the effect of improving the releasability is extremely insufficient or not at all. Did not.

[0009] On the other hand, there has been almost no technical proposal for preventing pit-like pores called satin on the coated resin surface of polyolefin resin-coated paper. The fact is that the situation is extremely poor. As one of the few technical proposals,
-198451, a technique for preventing crater-like pores by a sequential extrusion coating method divided into two layers of a polyolefin resin layer described in JP-A-198451 has been proposed. The effect of preventing pits was insufficient, especially at a production speed of 180 m / min or more. In addition,
According to the method for producing a polyolefin resin-coated paper in which the surface roughness Ra of the polyolefin resin layer described in JP-A No. 1-303435 is set to 1 μm or less and the linear pressure between the cooling roll and the backup roll is in a specific range, pit-like pores are formed. Although a technique for preventing pits has been proposed, the effect of preventing pit-like pores has not been sufficiently achieved even by using this technique.

[0010]

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 base paper surfaces was coated with a polyolefin resin,
An object of the present invention is to provide a polyolefin resin-coated paper excellent in smoothness without surface defects, in which generation of uneven peeling and generation of pit-like pores are remarkably suppressed. A second object of the present invention is to use a paper mainly composed of natural pulp as a substrate, and to coat one of the base paper surfaces with a polyolefin resin at a production speed of 180 m / min or more, thereby improving productivity and economy. An object of the present invention is to provide a polyolefin resin-coated paper excellent in smoothness and having excellent surface smoothness without surface defects, in which generation of peeling unevenness and generation of pit-like pores are remarkably suppressed. A third object of the present invention is to provide a polyolefin resin-coated paper excellent in smoothness without surface defects for use as a support for image materials. Other objects of the present invention will become clear from the description of the following specification.

[0011]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, using a paper mainly composed of natural pulp as a substrate, one base paper surface of which is a polyolefin resin (A In the polyolefin resin-coated paper coated with), the base paper has a center plane average roughness SRa (in the papermaking direction) in the papermaking direction at a cutoff value of 0.8 mm measured using a stylus type three-dimensional surface roughness meter. The term “center plane average roughness” is simply abbreviated as “center plane average roughness” hereinafter) of 1.4 μm.
The following, further polyolefin resin (A),
A titanium dioxide pigment resin composition comprising at least a polyolefin resin and a titanium dioxide pigment, and a titanium dioxide pigment resin produced by using a continuous kneading extruder having a mechanism for kneading between a rotating disk and a fixed disk. It has been found that the object of the present invention is achieved by a polyolefin resin-coated paper characterized by containing the composition.

The center plane average roughness SRa at a cutoff value of 0.8 mm measured using a stylus type three-dimensional surface roughness meter referred to in this specification is defined by the following equation (1).

[0013]

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

More specifically, as a stylus type three-dimensional surface roughness meter and a three-dimensional roughness analysis device, SE-produced by Kosaka Laboratory Co., Ltd.
Using a 3AK type machine and a SPA-11 type machine, the cutoff value is 0.8 mm, Wx = 20 mm, Wy = 8 mm, and therefore Sa = 1.
It can be obtained under the condition of 60 mm ² . As data processing in the X-axis direction, sampling was performed at 500 points, and
The scanning in the axial direction is performed for 17 lines or more.

An object of the present invention is to provide a polyolefin resin-coated paper in which one surface of a base paper mainly composed of natural pulp is coated with a polyolefin resin (A). A titanium dioxide pigment resin composition produced using a continuous kneading extruder having a SRa of 1.4 μm or less and having a mechanism for kneading a rotating disk and a fixed disk in a polyolefin resin (A). It has been found that synergistically achieved by incorporating Further, an object of the present invention is to use a polyethylene resin as the polyolefin resin (A), and to incorporate a high-pressure low-density polyethylene resin having a hexane extraction amount of 3% by weight or less in the polyethylene resin. As a result, it has been found that it is achieved remarkably. Furthermore, the object of the present invention was found to be remarkably achieved by using a continuous kneading extruder having a mechanism for kneading between a rotating disk and a fixed disk having a specific configuration as a continuous kneading extruder. It has arrived.

The base paper containing natural pulp as a main component used in the practice of the present invention has a center plane average roughness SRa of 1.4 μm or less as referred to in the present specification.
m or less, more preferably 1.1 μm or less, and most preferably 0.95 μm or less. The base paper having a center plane average roughness SRa of 1.4 μm or less is specifically obtained by using the following method, preferably by using two or more of the following methods, and more preferably by using three or more of the following methods in combination. The fact that it can be obtained has been clarified by the study of the present inventors.

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

(2) The pulp is beaten by a beater so that the long fiber content is reduced as much as possible.
Specifically, for example, the beating of pulp is done by JAPAN TA.
The length-weighted average fiber length measured in accordance with PPI paper pulp test method No. 52-89 "Fiber length test method for paper and pulp" is 0.4 mm to 0.75 mm, preferably 0.45 mm.
~ 0.7mm, more preferably 0.45mm ~ 0.65mm,
Cumulative weight of fiber length 1mm or less 70% or more, freeness 200
３３０330 CSF.

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

(4) 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 or in a base paper by a size press or a tab size press, or by a blade coating, an air knife coating, or the like. It is preferable that the coating amount is 2.2 g / m ² or more or the coating amount is applied.

(5) After the base paper is made, at least two or more series of calendar treatments are performed on the base paper using a machine calendar, a super calendar, a heat calendar, or the like. Specifically, for example, the base paper is subjected to at least one or more types of machine calendaring or thermal machine calendaring as a first series of calendaring, and then further machined as necessary as a second series of calendaring. After performing the calendering process, it is preferable to perform a thermal soft calendering process described or exemplified in JP-A-4-110939.

As the pulp constituting the base paper used in the practice of the present invention, it is advantageous to use appropriately selected natural pulp as described above. Natural pulp is chlorine,
Softwood pulp and hardwood pulp that have been subjected to normal bleaching treatment of hypochlorite and chlorine dioxide bleaching, and alkali extraction or alkali treatment and, if necessary, oxidative bleaching treatment with hydrogen peroxide, oxygen, etc., and a combination thereof Wood pulp mixed with softwood and hardwood pulp is used, and various pulp such as kraft pulp, sulfite pulp, and soda pulp can be used.

The base paper used in the practice of the present invention may contain various additives during preparation of 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 in or exemplified in JP-B-62-7534, and rosin derivatives. As a paper strength enhancer, anionic, cationic or amphoteric polyacrylamide, polyvinyl alcohol, cationized starch, vegetable galactomannan, etc., as a wet strength agent, polyamine polyamide epichlorohydrin resin, etc., as a filler, clay, kaolin , Calcium carbonate, titanium oxide, etc., as a fixing agent, water-soluble aluminum salts such as aluminum chloride, bansulfate, etc., pH
As a regulator, caustic soda, sodium carbonate, sulfuric acid and the like, and other appropriate combinations of the coloring pigments, coloring dyes, fluorescent brighteners and the like described or exemplified in JP-A-63-204251, JP-A-1-266537, etc. It is advantageous to incorporate them.

The base paper used in the practice of the present invention includes:
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,
Providing appropriate turbulence to stock slurry,
As a wet part press, using a fourdrinier paper machine having an appropriate upper dewatering mechanism as described or exemplified in JP-A-61-284762, a multi-stage wet press, preferably a three-stage or more wet press is performed. It is preferable to employ an appropriate papermaking method such as providing a smoothing roll at the last stage of the press part.

Further, a composition comprising various water-soluble polymers or hydrophilic colloids or latexes, an antistatic agent and additives is placed in or on a base paper used in the practice of the present invention by a size press or tub size. It can be contained or coated by coating such as pressing, 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 emulsions, emulsions or latexes of copolymers containing at least ethylene and acrylic acid (or methacrylic acid) as described or exemplified in JP-A-55-4027 and JP-A-1-180538, styrene Sodium chloride as an antistatic agent such as butadiene-based, styrene-acryl-based, vinyl acetate-acryl-based, ethylene-vinyl acetate-based, butadiene-methyl methacrylate-based copolymer and emulsion or latex of their carboxy-modified copolymers; Pigments such as alkali metal salts such as 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; , Calcium carbonate, talc, barium sulfate, titanium oxide, etc., as a pH adjusting agent, hydrochloric acid, phosphoric acid, citric acid, caustic soda, etc., in addition to the above-mentioned coloring pigments, coloring dyes, additives such as a fluorescent brightener, etc. It is advantageous to include it.

The thickness of the base paper used in the practice of the present invention is not particularly limited, but its basis weight is 20 g / m ^{2 to} 20 g / m ^2.
Those having 0 g / m ² are preferred.

As the base paper used in the practice of the present invention, use of pulp appropriately selected as described above,
The weighted average fiber length of the pulp after beating is 0.4 mm to 0.75
mm beating conditions, multi-stage pressing on wet paper, machine calendar on base paper, super calendar,
It is preferable that the thickness unevenness index Rpy in the papermaking direction defined below be 140 mV or less by employing a combination condition such as calendering treatment such as a thermal soft calender.
Those having a voltage of 32 mV or less are more preferable, and those having a voltage of 125 mV or less are most preferable. Here, the film thickness unevenness index Rpy is a value specifically determined as follows. A film manufactured by Anritsu Corporation for measuring a thickness variation of a sample as an electric signal via an electronic micrometer by moving a sample between two spherical styluses having a diameter of about 5 mm having a measurement pressure of about 30 g / stroke. Using a thickness measuring instrument, under the condition that the sensitivity range of the electronic micrometer is ± 15 μm / ± 3 V,
After the zero point adjustment, the thickness of the sample in the papermaking direction was measured by scanning at a constant speed of 1.5 m / min in the papermaking direction of the sample, and the obtained measured value was used as an FFT analyzer CF manufactured by Ono Sokki Co., Ltd.
-300 type machine (input signal AC ± 1 V, sampling 5
(12 points), fast Fourier transform (FFT) under processing conditions of a time window of a Hanning window and a frequency range of 50 Hz, and a power spectrum (unit: mV) on a linear scale based on an average of 128 integrations , And the value obtained by summing the squares of the power values on the linear scale in the frequency range of 2 Hz to 25 Hz is multiplied by 2/3 to obtain 1 /
It can be obtained by squaring. The other processing conditions are performed under the initial setting conditions of the CF-300 machine.

One surface of the base paper of the polyolefin resin-coated paper in the present invention is coated with the polyolefin resin (A). Examples of the polyolefin resin (A) include homopolymers such as polyethylene, polypropylene, polybutene and polypentene, copolymers composed of two or more α-olefins such as ethylene-butylene copolymer, and mixtures thereof. Particularly, a polyethylene resin is particularly preferable from the viewpoints of melt extrusion coating properties and adhesiveness to a base paper. Examples of such polyethylene resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene and propylene, copolymers of α-olefins such as butylene, carboxy-modified polyethylene, and the like. A mixture,
Various densities, melt flow rates (hereinafter simply abbreviated as MFR), molecular weights and molecular weight distributions can be used, but usually, the density 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 with an MFR of 0.1.
Those having a range of 3 g / 10 min to 40 g / 10 min can be advantageously used alone or in combination. When the resin has a multilayer structure, the outermost resin may have an MFR of, for example, 5 g / 10 min to 20 g / g.
10 minutes, lower layer resin, for example, MFR is 2 g /
It is also possible to use a resin having another property and constitution, such as using 10 minutes to 10 g / 10 minutes.

An object of the present invention is to use a polyethylene resin as the polyolefin resin (A), and to contain a high-pressure low-density polyethylene resin having a hexane extraction amount specified below of 3% by weight or less in the polyethylene resin. This is achieved remarkably. The hexane extraction amount referred to in the present specification refers to a thickness of about 3 processed at 150 ° C.
8μm blown film 15cm × 2.5cm
Approximately 2.5 g of the sample cut into strips was immersed in 300 ml of n-hexane kept at 50 ° C. and extracted for 2 hours. From the change in weight of the film before and after, the ratio of the weight reduced by the extraction to the weight before the extraction was calculated. It is a calculated value (unit:% by weight). As the high-pressure low-density polyethylene resin preferably used in the practice of the present invention and having a hexane extraction amount of 3% by weight or less, those having a hexane extraction amount of 2% by weight or less are more preferable. The content of the high-pressure method low-density polyethylene resin whose hexane extraction amount in the polyethylene resin is 3% by weight or less is effective at 25% by weight or more with respect to the total weight of the polyethylene resin. % By weight or more, more preferably 50% by weight or more.

The surface of the base paper of the polyolefin resin-coated paper of the present invention opposite to the side on which the polyolefin resin (A) layer is provided is preferably coated with a resin capable of forming a film. As these film-forming resins, thermoplastic resins such as polyolefin resins, polycarbonate resins, polyester resins, and polyamide resins are preferable,
Among them, the above-mentioned polyolefin resins are more preferable from the viewpoint of melt extrusion coating properties, and polyethylene resins are particularly preferable. Further, it may be coated with an electron beam curing resin described or exemplified in JP-B-60-17104.

The coating thickness of the polyolefin resin (A) of the polyolefin resin coated paper in the present invention is 4 μm.
A range from m to 100 μm is useful, but from 6 μm to 50 μm.
m is preferable, and a range of 9 μm to 35 μm is particularly preferable. The base paper surface on the opposite side coated with the polyolefin resin (A) is preferably coated with a resin capable of forming a film, and the resin is preferably the same resin as the polyolefin resin on the front side. It is preferable to set appropriately as long as the resin on the front side and the curl balance are particularly secured. Generally, the range of 4 μm to 100 μm is useful, but the range of 6 μm to 50 μm is preferable.

An object of the present invention is to provide a titanium dioxide pigment resin composition comprising at least a polyolefin resin and a titanium dioxide pigment on a specific base paper, and a mechanism for kneading between a rotating disk and a fixed disk. This is achieved by a polyolefin resin-coated paper coated with a polyolefin resin layer containing a titanium dioxide pigment resin composition produced using a continuous kneading extruder. On the other hand, a titanium dioxide pigment resin composition produced by using a batch kneader such as a Banbury mixer or a kneader described or disclosed in Japanese Patent Publication No. 1-38291 or a knee disclosed or disclosed in JP-A-64-46749. Even if the titanium dioxide pigment resin composition manufactured by using the twin-screw kneading extruder in which the loading disk is arranged or the titanium dioxide resin composition manufactured by using another single-screw kneading extruder is contained in the polyolefin resin, The effect of the present invention cannot be obtained. As a method for incorporating the titanium dioxide pigment resin composition used in the practice of the present invention into a polyolefin resin for coating a base paper, a so-called master batch in which a titanium dioxide pigment is previously contained at a certain concentration in a polyolefin resin is prepared. Then, it is used by diluting and mixing it in a desired ratio with a polyolefin resin for dilution, or using a so-called compound in which a titanium dioxide pigment is contained in a polyolefin resin in a desired composition ratio. Appropriate.

A continuous kneading extruder having a mechanism for kneading between a rotating disk and a fixed disk used in the production of the titanium dioxide pigment resin composition used in the practice of the present invention has the mechanism. The kneadability of the titanium dioxide pigment and a polyolefin resin, preferably a polyethylene resin, and a dispersant such as zinc stearate and magnesium stearate used as needed, and a titanium dioxide pigment are not particularly limited. From the viewpoint of the dispersibility of the present invention and the effect of the present invention, the rotating disk is fixed at the center to the rotating shaft having a screw formed on the outer periphery so as to rotate in the cylinder and transfer the fluid in the axial direction. Peaks and valleys are alternately radially formed on at least one surface of the rotating disk, and a fixed disk is fixed to the cylinder coaxially opposite to this surface. The fixed disk is arranged so that a gap is formed between the fixed disk and the surface of the fixed disk facing the rotary disk, and peaks and valleys are alternately radially formed on the surface of the fixed disk. Fluid fed through between the plate and the rotating shaft is pushed outward in the valley between the two disks by the boundary line between the two disks, and between the outer peripheral portion of the rotating disk and the inner surface of the cylinder. The continuous kneading extruder is preferably configured so as to be fed out.In particular, peaks and valleys are alternately formed radially on the other surface of the rotating disk, and the fixed circle is opposed to this surface. A fixed disk similar to the plate is arranged, and between the two surfaces, fluid from the outer periphery of the rotating disk is sent toward the center by the boundary between the peaks and valleys, and the rotating shaft and the fixed circle It is configured to be extruded from the gap with the plate, It is more preferable that a plurality of fixed disks and a plurality of rotating disks are respectively arranged.Specific examples of these continuous kneading extruders include JP-B-54-24743, JP-B-55-41139, and resin"
Vol. 34, No. 1, 1, pp. 22-29.

The titanium dioxide pigment used in the production of the titanium dioxide pigment resin composition used in the practice of the present invention includes a sulfuric acid method, a chlorine method, a rutile type,
Various titanium dioxide pigments such as an anatase type, a surface treated with a hydrated metal oxide, and a surface treated with an organic compound can be used, and a suitably designed titanium dioxide pigment is preferable. For example, titanium dioxide pigments described in JP-B-63-11655 or exemplified by mildly hydrated alumina, titanium dioxide having a suspension electric conductivity of a specific value or less described in JP-B-1-38291 or exemplified. Pigments, titanium dioxide pigments appropriately pulverized by a fluid energy mill described or exemplified in JP-B-1-38292, internally coated titanium dioxide pigments described or exemplified in JP-A-1-105245, JP-B A titanium dioxide pigment having a particle size in a specific range described or exemplified in 2-38938, an alkaline earth metal compound described or exemplified in JP-A-4-52639, and a step of pickling after firing is added. Titanium dioxide pigment having a specific range of particle size,
Titanium dioxide pigment surface-treated with organosilicon or alkanolamine described or exemplified in JP-B-60-3430, titanium dioxide surface-treated with polyhydric alcohol-based compound described or exemplified in JP-B-59-37304 It is preferable to use various appropriately designed titanium dioxide pigments, such as pigments, titanium dioxide pigments described in JP-B-61-26652 or exemplified by surface treatment with an organopolysiloxane. Further, as the titanium dioxide pigment resin composition used in the practice of the present invention, as described in JP-B-1-38293 or as exemplified, its resin pressure is 20 kg / c.
Those having less than m ² are preferred.

As a method for coating a polyolefin resin, preferably a polyethylene resin, on the base paper surface of the polyolefin resin-coated paper in the present invention, a resin is extruded onto a running base paper using a melt extruder to form a film from its slit die. It is preferable to coat by a so-called melt extrusion coating method of casting and coating. that time,
The temperature of the molten film is preferably 270 ° C to 330 ° C. As the slit die, a flat die such as a T-type die, an L-type die, and a fishtail type die is preferable.
The slit opening diameter is desirably 0.1 mm to 2 mm. Before coating the resin on the base paper, the base paper is preferably subjected to an activation treatment such as a corona discharge treatment or a flame treatment. Also, as described in JP-B-61-42254,
It is preferable to coat the resin layer on the running base paper after blowing the ozone-containing gas onto the surface of the molten resin in contact with the base paper. If the base paper is coated on both sides with resin,
The backing resin layer is preferably sequentially, preferably continuously, extrusion-coated on the base paper in a so-called tandem extrusion coating system. The resin layer surface can be processed into a glossy surface, a finely rough surface described in JP-B-62-19732, a matte surface, a silk surface, or the like. In particular, the effect of the present invention is remarkable in a polyolefin resin-coated paper in which the polyolefin resin layer has a glossy surface or a slightly rough surface.

Various additives can be contained in the resin layer of the polyolefin resin-coated paper of the present invention. In addition to titanium dioxide pigments, zinc oxide, talc, white pigments such as calcium carbonate, release agents such as stearamide, fatty acid amides such as arachidic amide, titanium dioxide pigments and other pigment dispersants and release agents, Fatty acid metal salts such as zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, zinc palmitate, zinc myristate, calcium palmitate, hindered phenols and hindered amines described or exemplified in JP-A-1-105245, Various antioxidants such as phosphorus and sulfur, pigments and dyes such as blue, such as cobalt blue, ultramarine blue, celian blue, and phthalocyanine blue, pigments and dyes such as cobalt violet, fast violet, and manganese violet, etc. 4-2175 Quinacridone red pigments described or illustrated in broadcast, fluorescent whitening agents described or exemplified in JP-A-2-254440, various additives as appropriate combination can be incorporated such as an ultraviolet absorber.
These additives are preferably contained in the titanium dioxide pigment resin composition used in the practice of the present invention in combination or as a separate resin master batch or compound.

The surface of the polyolefin resin (A) layer of the paper coated with the polyolefin resin in the present invention and, if necessary, the surface on the opposite side, preferably a resin (B) capable of forming a film.
An activation treatment such as a corona discharge treatment or a flame treatment can be applied to the surface of the resin layer covered with. Further, after the activation treatment, an undercoating treatment as described or exemplified in JP-A-1-102551 and JP-A-1-66035 can be performed.

The surface of the polyolefin resin-coated paper according to the present invention opposite to the surface of the polyolefin resin (A) layer, preferably the surface of the resin layer coated with the resin (B) capable of forming a film, is subjected to corona discharge treatment and flame treatment. After performing such an activation treatment, various types of back coat layers can be applied for antistatic and curling prevention. Further, the back coat layer, JP-B-52-18020, JP-B-57-9059, JP-B-57-53940, JP-B-58-56859, JP-A-59-2
No. 14849, 58-184144 or the like, or an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a pigment, a surfactant and the like can be appropriately combined and contained. .

The polyolefin resin-coated paper in the present invention has a film thickness unevenness index Rpy of 170 in the present specification.
mV or less is preferable, 160 mV or less is more preferable, and 150 mV or less is more preferable.

The polyolefin resin-coated paper of the present invention is coated with various photographic constituent layers and is used for color photographic printing paper, black-and-white photographic printing paper, photolithographic printing paper, computerized photolithographic printing paper, laser light sensitive photographic paper. Photographic papers, reversal photographic materials, silver salt diffusion transfer method negative and positive, and printing materials. For example, a silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide photosensitive emulsion layer can be provided. By incorporating a color coupler into the silver halide light-sensitive emulsion layer, a multilayer silver halide color photographic constituting layer can be provided. Further, a photographic component layer for a 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, 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,
Hardeners such as formalin, vinyl sulfone compounds and aziridine compounds, and coating aids such as alkylbenzene sulfonates and sulfosuccinates, as well as fluorescent whitening agents, sharpness improving dyes, antistatic agents, pH
A water-soluble iridium, a water-soluble rhodium compound, and the like can be incorporated in a suitable combination during the formation and dispersion of the 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 Materials and Handling Methods" (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 polyolefin resin coated paper of 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 thereof 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, extenders such as silica, calcium carbonate, titanium oxide, and zinc oxide are preferable. Further, the thickness of the image receiving layer is preferably 0.5 to 20 μm, more preferably 2 to 10 μm.

The polyolefin resin-coated paper of the present invention is provided with various ink receiving layers and can be used as a support for various ink jet recording materials. Various binders can be contained in the ink receiving layer for the purpose of improving the drying property of the ink, the sharpness of the image, and the like. Specific examples of such binders include:
Lime-treated gelatin, acid-treated gelatin, enzyme-treated gelatin, gelatin derivatives such as phthalic acid, maleic acid,
Various gelatins such as gelatin reacted with anhydrides of dibasic acids such as fumaric acid, ordinary polyvinyl alcohols of various saponification degrees, carboxy-modified, cation-modified and amphoteric polyvinyl alcohols and their derivatives, oxidized starch, cationization Starch, starches such as etherified starch, carboxymethylcellulose, cellulose derivatives such as hydroxyethylcellulose, polyvinylpyrrolidone, polyvinylpyridium halide, sodium polyacrylate, methacrylic acid copolymer salt, polyethylene glycol, Polypropylene glycol, polyvinyl ether, alkyl vinyl ether / maleic anhydride copolymer, styrene / maleic anhydride copolymer and salts thereof, synthetic polymers such as polyethyleneimine, styrene / butadiene copolymer, methyl meta Conjugated diene copolymer latexes such Relate-butadiene copolymer, polyvinyl acetate, vinyl acetate-maleate copolymers, vinyl acetate-
Acrylic ester copolymer, vinyl acetate polymer latex such as ethylene / vinyl acetate copolymer, acrylate ester polymer, methacrylate ester polymer, ethylene / acrylate ester copolymer, styrene / acrylate ester copolymer Latex of acrylic polymer or copolymer such as polymer, latex of vinylidene chloride copolymer or functional group-modified polymer latex by functional group-containing monomer such as carboxyl group of these various polymers, melamine Aqueous adhesives such as thermosetting synthetic resins such as resins and urea resins, and synthetic resin adhesives such as polymethyl methacrylate, polyurethane resins, unsaturated polyester resins, vinyl chloride / vinyl acetate copolymers, polyvinyl butyral, and alkyd resins; Japanese Patent Publication No. 3-24906, JP-A-3-2813
Inorganic binders such as alumina sol, silica sol and the like described or exemplified in JP-A-83-83, and Japanese Patent Application No. 4-240725 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,
Examples of hardening agents such as acryloyl compounds and isocyanate compounds and preservatives include P-hydroxybenzoic acid ester compounds, benzisothiazolone compounds, and isothiazolone compounds described or exemplified in JP-A-1-102551, and 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-di-alkylphenyl group at the 2-position as ultraviolet absorbers; Japanese Patent No. 4-1337 discloses organic or inorganic fine particles having a particle size of 0.2 μm to 5 μm, such as starch granules, barium sulfate, and silicon dioxide, as pencil writing agents such as the polyhindered phenol compounds described or exemplified in Japanese Patent No. 105245. Appropriate combinations of organopolysiloxane compounds described or exemplified in gazettes and the like, and various additives such as caustic soda, sodium carbonate, sulfuric acid, hydrochloric acid, phosphoric acid, citric acid, octyl alcohol, and silicon-based antifoaming agents as a pH adjuster Can be included.

The polyolefin resin-coated paper of the present invention can be used for other purposes such as printing.

[0047]

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.

Example 1 Fiber length of pulp after beaten a mixed pulp composed of 70% by weight of hardwood bleached kraft pulp and 30% by weight of hardwood bleached sulphite pulp (JAPAN TAPPI paper pulp test method No. 52-89 "Paper and pulp" The fiber was beaten so that the length-weighted average fiber length measured in accordance with “Fiber length test method” was 0.62 mm, and then 3 parts by weight of cationized starch, 100 parts by weight of pulp, and anionization 0.2 parts by weight of polyacrylamide, 0.4 parts by weight of an alkyl ketene dimer emulsion (as ketene dimer), 0.4 parts by weight of a polyamide epichlorohydrin resin and appropriate amounts of a fluorescent brightener, a blue dye and a red dye are added. To prepare a stock slurry. Thereafter, the stock slurry was placed on a fourdrinier paper machine running at 200 m / min, and a paper web was formed while giving appropriate turbulence.
After performing a three-stage wet press in which the linear pressure was adjusted in the range of m to 100 kg / cm, it was treated with a smoothing roll, and the linear pressure was adjusted in the range of 30 kg / cm to 70 kg / cm in the subsequent drying part. After two-stage pressing, drying was performed.
Thereafter, during the drying, 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 of water
The size press solution consisting of parts by weight is subjected to a size press of 25 g / m ² , dried so that the finally obtained base paper moisture becomes 8% by weight with absolutely dry water, and machine calendered at a linear pressure of 70 kg / cm. Subsequently, a thermal soft calender treatment was performed under the conditions shown in Table 1 to produce a base paper of a polyolefin resin-coated paper having a basis weight of 170 g / m ² and having a center plane average roughness SRa shown in Table 1.

Next, after the base paper surface opposite to the side coated with the polyolefin resin (A) was subjected to corona discharge treatment, a low-density polyethylene resin (density 0.92 g / cm) was used as a resin (B) having a film forming ability. ³ , MFR = 2 g / 10 min) 35 parts by weight and high density polyethylene resin (density 0.96 g / cm ³ ,
(MFR = 20 g / 10 min) A compound resin composition consisting of 65 parts by weight was melt-extruded and coated at a resin temperature of 320 ° C. to a thickness of 28 μm at a running speed of the base paper of 180 m / min.

Subsequently, the surface of the uncoated base paper was subjected to corona discharge treatment, and then 20 parts by weight of the following master batch (1M), (2M) or (3M) of titanium dioxide pigment, a low-density polyethylene for dilution, Resin (density 0.92g /
cm ³ , MFR = 4.5 g / 10 min, hexane extraction amount = 3.5 wt% as used herein) 70 parts by weight and a high-density polyethylene resin for dilution (density 0.97 g / cm ³ , MFR = 7) 0.0g
/ 10 minutes) A resin composition consisting of 10 parts by weight was heated to a resin temperature of 32.
The composition was melt-extruded to a thickness of 30 μm at 5 ° C. with the combination shown in Table 1 at a running speed of the base paper of 180 m / min and a cooling roll temperature of 12 ° C. In addition, the melt extrusion coating of the front and back polyethylene resins was performed by a so-called tandem method in which extrusion coating was performed sequentially. At this time, the surface of the resin layer containing the titanium dioxide pigment of the resin-coated paper was processed into a mirror surface, and the surface quality of the resin layer on the back was processed into a matte surface such as paper to obtain a polyethylene resin-coated paper.

The following (1M), (2M) or (3M) was used as a master batch of titanium dioxide pigment. As the master batch (1M) in the present invention, a low-density polyethylene resin (density 0.92 g / cm ³ , MFR =
8.5 g / 10 min, hexane extraction in this specification = 3.5
47.5% by weight) and hydrous aluminum hydroxide (0.75% by weight in terms of Al ₂ O _{3 based} on titanium dioxide)
Having a mechanism for kneading 50% by weight of anatase-type titanium dioxide pigment surface-treated with 2.5% by weight of zinc stearate between a rotating disk and a fixed disk, manufactured by K.C.K. Kneading with a general-purpose KCK continuous kneading extruder,
A master batch of titanium dioxide pigment produced by cooling and pelletizing was used. On the other hand, as a comparative product (2M), 47.5% by weight of the low-density polyethylene resin, 50% by weight of the above-mentioned titanium dioxide pigment and 2.5% by weight of zinc stearate were kneaded with a Banbury mixer, cooled, and cooled.
A masterbatch of titanium dioxide pigment produced by pelletization was used. As a comparative product (3M), 47.5% by weight of the low-density polyethylene resin, 50% by weight of the above-mentioned titanium dioxide pigment, and 2.5% by weight of zinc stearate were kneaded by a usual twin-screw kneading extruder. Then, a master batch of titanium dioxide pigment produced by cooling, pelletizing and using was used.

The surface condition of the mirror surface on the front side of the obtained polyethylene resin-coated paper was observed, and the results shown in Table 1 were obtained.

[0053]

[Table 1]

Note that (Note 1) to (Note 4) in Table 1 are as follows.

(Note 1) ○ indicates a sample No. according to the present invention.

(Note 2) Indicates the average surface roughness SRa (μm) of the base paper surface on the side where the polyolefin resin (A) is provided, measured by the method specified in the present specification.

(Note 3) The degree of occurrence of uneven peeling was visually determined by obliquely observing the mirror surface of the polyethylene resin-coated paper. The evaluation criteria are as follows.

A: There is no or very little peeling unevenness. ：: Little occurrence of uneven peeling. □: Little occurrence of uneven peeling. Δ: The occurrence of uneven peeling is slightly large, but practical. ×: There are many occurrences of peeling unevenness, and there is a problem in practical use.

(Note 4) Regarding the degree of generation of pit-shaped pores, the mirror surface of the polyethylene resin-coated paper was scanned with a three-dimensional surface roughness meter, and an image of the surface state of the resin-coated paper was converted to an X-ray. The degree of generation of pit-shaped pores was visually determined by drawing with a Y plotter. The evaluation criteria are as follows.

◎: No pit-shaped pores were generated or they were extremely small. ：: generation of pit-shaped pores is small. □: Pit-shaped pores are slightly generated. Δ: Pit-shaped pores are slightly generated, but practical. ×: Many pit-shaped pores are generated, and there is a problem in practical use.

As is clear from Table 1, the center plane average roughness SR
Contains a titanium dioxide pigment resin composition manufactured using a continuous kneading extruder having a mechanism of kneading the base paper surface between a rotating disk and a fixed disk using paper having a of 1.4 μm or less as a substrate. It can be understood that the polyethylene resin-coated paper of the present invention coated with the polyethylene resin to be produced is an excellent resin-coated paper having less occurrence of peeling unevenness and less occurrence of pit-like pores and having no surface defects. The base paper of the present invention has a center surface average roughness SRa of 1 on the side coated with the resin (A) from the viewpoint of the effect of improving the peeling unevenness and particularly the effect of improving the pit-shaped pores. .25 μm
It is understood that the following are preferred, those having a size of 1.1 μm or less are more preferred, and those having a size of 0.95 μm or less are most preferred. On the other hand, when a base paper having a center plane average roughness SRa larger than 1.4 μm is used, or when a titanium dioxide pigment resin composition other than the present invention is used, the resin-coated paper outside the present invention has uneven peeling. It can be seen that there is a problem due to the large number of pit-like pores and the large number of pit-like pores.

Example 2 In the sample No. 13 of Example 1, a low density polyethylene resin for dilution (density 0.92 g / cm ³ , MFR = 4.5 g /
10 minutes, extraction amount of hexane referred to in this specification = 3.5% by weight)
Is replaced by a low-density polyethylene resin having a hexane extraction amount of 1.6% by weight (a density of 0.92 g / cm
³ , MFR 3.6 g / 10 min) as the diluting resin in the amount shown in Table 2, and the running speed of the base paper was set to 180 m / min, 215
m / min or 250 m / min except for sample No. 1 of Example 1.
The same operation as in Example 3 was performed. Table 2 shows the obtained results.

[0063]

[Table 2]

Incidentally, (Note 5) to (Note 7) in Table 2 are as follows.

(Note 5) The ratio of the weight of the low-density polyethylene resin whose hexane extraction amount is 1.6% by weight to the weight of the total polyethylene resin in the polyethylene resin (A) layer on the mirror surface on the front side of the resin-coated paper is expressed by weight. It is displayed in%.

(Note 6) and (Note 7) are the same as (Note 3) and (Note 4) in Table 1, respectively.

As is clear from Table 2, the effect of the present invention can be remarkably achieved by adding a low-density polyethylene resin having an extraction amount of hexane of 3% by weight or less to the polyolefin resin (A) layer. . Further, it is understood that the content is preferably 25% by weight or more, more preferably 35% by weight or more, and particularly preferably 50% by weight or more, from the viewpoint of the effect of improving the uneven peeling and the pit-like pores.

Example 3 A sample was prepared in the same manner as in Sample No. 28 of Example 2 except that the same amount of the following resin was used instead of the low-density polyethylene resin for dilution used in Sample No. 28 of Example 2. Table 3 shows the obtained results.

Resin (a): Low-density polyethylene resin for dilution used in Example 1 (density 0.92 g / cm ³ , MFR =
4.5 g / 10 minutes). Resin (b): The amount of hexane extracted in this specification is 3% by weight
Low density polyethylene resin (density 0.92 g / cm ³ ,
MFR = 4.3 g / 10 min). Resin (c): a low-density polyethylene resin having a hexane extraction amount of 2.3% by weight (a density of 0.92 g / cm)
³ , MFR = 4.0 g / 10 min). Resin (d): Low-density polyethylene resin (density 0.92 g / cm ³ , MFR = 3.6) used in sample No. 28 of Example 2.
g / 10 minutes).

[0070]

[Table 3]

Note that (Note 8) and (Note 9) in Table 3
These are the same as (Note 3) and (Note 4) in Table 1, respectively.

As is apparent from Table 3, the low-density polyethylene resin preferably contained in the polyolefin resin (A) includes a hexane extraction amount referred to in the present specification in view of the effect of improving the peeling unevenness and the pit-like pores. It is well understood that the content is preferably 3% by weight or less, more preferably 2.5% by weight or less, and particularly preferably 2% by weight or less.

Example 4 A low-density polyethylene resin (density 0.92 g / cm ³ , MFR =
6 g / 10 min) Random polypropylene resin (density 0.90 g / cm ³ , 20% by weight and 5 mol% ethylene component)
MFR = 28 g / 10 min) 80 wt% was kneaded and extruded using a twin-screw kneading extruder, then cooled and pelletized to produce a polypropylene resin (density 0.90 g / cm ³ , MF
(R = 21 g / 10 min) 89.5 parts by weight of the titanium dioxide pigment used in Example 1, 10 parts by weight of zinc stearate and 0.5 part by weight of zinc stearate were continuously kneaded with KCK for general use. The procedure was performed in the same manner as in Sample No. 14 of Example 1, except that a titanium dioxide pigment compound resin composition produced by kneading with an extruder, cooling and pelletizing was used. As a result, an excellent polypropylene-based resin-coated paper free from surface defects and having very little peeling unevenness and little pit-like pores was obtained.

Example 5 A polyethylene resin-coated paper was produced in the same manner as in Sample No. 31 of Example 2 and for comparison, Sample No. 2 of Example 1. At that time, after a corona discharge treatment was applied to the backside resin layer of the resin-coated paper, 8 g of a 25% by weight aqueous solution of styrene / maleic anhydride copolymer sodium salt, 1 g of starch particles having an average particle diameter of 0.4 μm, and 1 g of styrene / acrylic latex were used. 45% by weight
2 g of liquid (Bonlon SX-224 manufactured by Mitsui Toatsu Co., Ltd.)
40 g of a 20% by weight aqueous dispersion of colloidal silica, a water-soluble epoxy compound (NER-010 manufactured by Nagase & Co., Ltd.)
Of a 20% by weight methanol solution and 1 g of a 5% by weight aqueous solution of sodium dodecylbenzenesulfonate, the total amount of which was adjusted to 100 g with water, at a coating amount of 3 g / m ² (moisture). On-machine application was uniform. Subsequently, a corona discharge treatment was applied to the resin surface on the front side of the support until the resin-coated paper was wound up, and 1.5 g of lime-treated gelatin, 0.3 g of a 10% by weight methanol solution of butyl parahydroxybenzoate, Formulation containing 0.45 g of a 5 wt% mixed solution of methanol and water of an acid-2-ethylhexyl ester salt and 0.36 g of a 10 wt% aqueous solution of an amphoteric surfactant represented by Chemical Formula 1, and the total amount was adjusted to 100 g with water. The undercoating solution was uniformly applied on-machine so that the coating amount of gelatin was 0.06 g / m ² to obtain a support for an image material.

[0075]

Embedded image

Next, the following multilayer silver halide color photographic constituting layer or ink jet receiving layer is coated on the undercoat layer on the front side of the support for image materials to form a silver halide color photographic printing paper or ink jet recording sheet. Manufactured.
As a result, an excellent color photographic printing paper or ink jet recording sheet having no surface defects and high gloss was obtained.

The multilayer silver halide color photographic constituting layer is composed of a blue-sensitive silver halide emulsion layer, an intermediate layer, a green-sensitive silver halide emulsion layer, an ultraviolet absorbing layer, Six layers were simultaneously coated from a multilayer coating E bar so that the red-sensitive silver halide emulsion layer and the protective layer were located.

The blue-sensitive silver halide photographic constituent layer has a halogen composition of AgBr / AgCl = 95/5 produced by the first thermoforming in the presence of an appropriate amount of potassium hexachloroiridate (III), and has an average grain size of 0/5. A neutral silver halide emulsion composed of a mixed crystal of [1, 0, 0] and [1, 1, 1] planes sensitized to an optimum sensitivity of 0.8 μm by sulfur was added at a silver nitrate content of 0.6.
g / m ^2, and in addition to gelatin 1.5 g / m ² and a yellow-color forming coupler, an appropriate amount of a stabilizer, a sensitizing dye for blue sensation, a coating aid, a hardener, a thickener and the like. The intermediate layer is composed of gelatin 1.
In addition to 5g / m ² , an appropriate amount of anti-color mixing agent, coating aid, thickener,
Including hardeners. The green-sensitive silver halide emulsion layer has a halogen composition of AgBr / AgCl = 95/5 produced by the first thermoforming in the presence of appropriate amounts of potassium hexachlororhodate (III) and potassium hexachloroiridium (III) ate. An acid-processed silver halide emulsion consisting essentially of [1,0,0] plane sulfur-sensitized to an optimum sensitivity with an average grain size of 0.4 μm containing 0.6 g / m ² of silver nitrate, and 1.5 g of gelatin / m ² and a magenta color coupler, in addition to an appropriate amount of a stabilizer, a sensitizing dye for greening, a sharpness improving dye, a coating aid, a hardener, a thickener, and the like. The UV absorbing layer is gelatin 1.5
In addition to g / m ² , it contains an appropriate amount of an ultraviolet absorber, a coating aid, a thickener, a hardener, and the like.

The red-sensitive silver halide emulsion layer contains a silver halide emulsion prepared in exactly the same manner as the green-sensitive silver halide emulsion at a silver nitrate content of 0.6 g / m ² , and further has a gelatin of 1.5 g / m ^2.
And an appropriate amount of a stabilizer, a sensitizing dye for red sensation, a sharpness improving dye, a coating aid, a hardener, a thickener and the like in addition to a cyan coloring coupler. The protective layer contains an appropriate amount of a coating aid, a thickener, a hardener and the like in addition to gelatin 1.5 g / m ² .

The ink jet receiving layer was made of 6 g / m ^{2 of} lime-treated gelatin, 80 g of a 5% aqueous solution of methyl vinyl ether / maleic acid copolymer at pH 7.0, and 5 g of methanol and water of sulfosuccinic acid-2-ethylhexyl ester salt.
A coating solution containing 1 g of a weight% mixed solution, the total amount of which was adjusted to 160 g with water, was applied by an E bar at a coating amount of 160 g / m ² (moisture).

[0081]

Industrial Applicability According to the present invention, polyolefin resin-coated paper having excellent surface smoothness without surface defects, in which the occurrence of uneven peeling and the occurrence of pit-like pores are remarkably suppressed, particularly, as a support for image materials A polyolefin resin-coated paper suitable for the present invention can be provided.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FI G03C 1/79 G03C 1/79 (56) References JP-A-3-65948 (JP, A) JP-A-4-136934 (JP) , A) JP-A-4-110939 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (6)

(57) [Claims] 1. A polyolefin resin-coated paper in which a paper mainly composed of natural pulp is used as a substrate and one of the paper substrates is coated with a polyolefin resin (A). Center plane average roughness SR in the papermaking direction at a cutoff value of 0.8 mm measured using a roughness meter
a is equal to or less than 1.4 μm, and the polyolefin resin (A) is a titanium dioxide pigment resin composition comprising at least a polyolefin resin and a titanium dioxide pigment, and has a thickness between the rotating disk and the fixed disk. A polyolefin resin-coated paper containing a titanium dioxide pigment resin composition produced using a continuous kneading extruder having a kneading mechanism. 2. The polyolefin resin-coated paper according to claim 1, wherein the polyolefin resin (A) is a polyethylene resin. 3. The polyolefin resin-coated paper according to claim 2, wherein the polyethylene resin contains a high-pressure low-density polyethylene resin having an extraction amount of hexane specified below of 3% by weight or less. Hexane extraction amount: About 2.5% of a sample obtained by cutting an inflation film having a thickness of about 38 μm processed at 150 ° C. into a 15 cm × 2.5 cm strip
g was immersed in 300 ml of n-hexane kept at 50 ° C. and extracted for 2 hours. From the weight change of the film before and after, the ratio of the weight reduced by the extraction to the weight before the extraction was determined.
This ratio is defined as the amount of hexane extracted (%). 4. The polyolefin resin-coated paper according to claim 3, wherein the content of the high-pressure low-density polyethylene resin whose hexane extraction amount is 3% by weight or less is 25% by weight or more based on the total resin weight. 5. A rotating disk is fixed at a central portion thereof to a rotating shaft having a screw formed on an outer peripheral portion so that a continuous kneading extruder rotates in a cylinder and transfers a fluid in the axial direction. Crests and valleys are alternately radially formed on at least one surface of the rotating disk, and a fixed disk is fixed to the cylinder coaxially in opposition to this surface, and between the rotating shaft. While being arranged so that a gap is formed,
Peaks and valleys are alternately formed radially on the surface of the fixed disk facing the rotating disk, and the fluid fed through between the fixed disk and the rotating shaft is used for the two disks. 4. A structure in which the outer peripheral portion of the rotating disk is pushed out between the outer peripheral portion of the rotating disk and the inner surface of the cylinder by being pushed out in an outer peripheral direction by a boundary portion between the two disks. Or the polyolefin resin-coated paper according to 4. 6. The polyolefin resin (A) wherein the paper substrate surface opposite to the side to be coated is coated with a film-forming resin (B). The polyolefin resin-coated paper according to 5.