JPH09216456A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium which has a high ink absorp tive property, an equally high degree of luster and an equal image sharpness to a silver salt photograph. SOLUTION: In this ink jet recording medium consisting of an ink recording layer formed on a support, the ink recording layer is composed of a resin composition containing a thermoplastic hydrophilic resin, and is formed by a melt extrusion coating method. The melting point of the thermoplastic hydrophilic resin should preferably be 210 deg.C or less and its melt flow ratio (temperature: 190 deg.C, load: 2160g) be 1-50g/10min.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording material, and more particularly to an ink jet recording material having excellent ink absorbency and high glossiness and image sharpness equivalent to those of silver salt photographs.

[0002]

2. Description of the Related Art An ink jet recording system, unlike a thermal transfer recording system, does not require an ink sheet and is easy to maintain.
Further, since it does not require the developing and fixing processes as in the electrophotographic system, it has features that the device can be made compact and high-speed color recording can be performed at high speed. Therefore, in recent years, it has rapidly become widespread as an output method for an output printer or facsimile of a personal computer or a copying machine. In addition, due to the high performance of personal computers and the spread of multimedia, the chances of printing out not only documents but also color images will increase, the ink absorbency will be excellent, and the gloss level will be as high as silver halide photography. There is an increasing need for an inkjet recording body that can obtain a recorded image having image sharpness.

Conventionally, a so-called plain paper type ink jet recording material obtained by processing pulp paper has been generally used as the ink jet recording material. However, when recording a color image, the dot shape and the dot shape are used. From the sharpness, ink absorption capacity, ink absorption speed, ink receptivity such as dye fixing of ink, a paint prepared by mixing an absorbing inorganic pigment such as silica and a binder such as polyvinyl alcohol, polyvinylpyrrolidone or gelatin. ,
A coated paper type ink jet recording material coated on pulp paper is preferred. However, in a usual coated paper type inkjet recording body, in the process of coating and drying the ink recording layer on the pulp paper, shrinkage unevenness occurs due to the paper making texture of the pulp paper, and some blistering appears on the surface. However, if the gloss is insufficient, or if the content of the absorbing pigment is increased, there is a problem that the graininess causes the graininess to reduce the gloss.

In Japanese Patent Publication No. 3-25352, a support such as cast coated paper having a surface gloss of 80% or more or a plastic sheet having a Hunter whiteness of 80% or more has a saponification degree of 50 to 90 mol. There is disclosed an inkjet recording paper having strong gloss, which is characterized in that a film containing a cross-linking agent in an amount of 5% to 50% by weight of polyvinyl alcohol and polyvinyl alcohol is formed. However, even if cast-coated paper is used as the pulp paper, since water is once absorbed in the step of coating and drying the coating material, the occurrence of lumpiness in the drying step cannot be suppressed and the gloss is insufficient. Alternatively, if a plastic sheet is used, high gloss can be obtained without blistering due to the texture of the support, but the plastic sheet is generally more expensive than pulp paper, and it has a feeling of touch, texture, and rigidity. In short, it was not possible to satisfy the demands of the market.

Japanese Patent Laid-Open No. 5-212952 discloses an ink jet recording body in which a support is provided with a binder-containing ink receiving layer, the ink receiving layer contains a hydrophilic binder and polyethylene oxide, and polyethylene oxide is used. , An ink jet recording material characterized by being present as an oxidized polyethylene emulsified by cationic activity in an aqueous coating material used for an ink receiving layer. Also disclosed is an ink jet recording material in which the support is a polyolefin-coated base paper or a plastic film. However, when such a polyolefin-coated base paper is used, a high-gloss inkjet recording material can be obtained, but in order to achieve the ink absorption required for color recording, the ink recording layer should be relatively thick, Coating amount 15g /
It is necessary to make it about m ² or more. Usually, the ink recording layer is applied as a water-based paint, but in order to obtain a sufficient coating amount, it is necessary to increase the coating concentration or increase the wet coating amount. However, the concentration of these paints is usually 10
If the concentration is limited to about 20% by weight and the concentration is excessively increased, the viscosity of the coating material increases rapidly, which makes handling by a coater difficult. Alternatively, when trying to increase the wet coating amount, not only the coating surface becomes rough, but even if it can be coated, the drying load of the coating machine becomes excessive, heat shrinkage of the base material occurs, and the gloss decreases. Or, inconveniences such as reduced productivity occurred.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above problems and, when printed by an ink jet printer,
Provided is an inkjet recording material having excellent ink absorbency and having high glossiness and image sharpness equivalent to those of a silver salt photograph.

[0007]

The present invention includes the following aspects. [1] In an inkjet recording body having an ink recording layer on a support, the ink recording layer is made of a resin composition containing a hydrophilic resin having thermoplasticity, and the ink recording layer is formed by a melt extrusion coating method. Characteristic inkjet recording material.

[2] The melting point of the hydrophilic resin having thermoplasticity is 210 ° C. or less, and the melt flow ratio (temperature 190).
The inkjet recording material according to [1], wherein the temperature is 2160 g and the load is 1 to 50 g / 10 minutes.

[3] The hydrophilic resin having thermoplasticity is
The inkjet recording material according to [1] or [2], which is a copolymer resin containing at least an ethylene unit and a vinyl alcohol unit.

[4] The hydrophilic resin having thermoplasticity is
[1] or [2], which is a copolymer resin containing at least a vinyl acetate unit, a vinyl alcohol unit, and an ethylene unit having a hydrophilic group in a side chain.
The inkjet recording material described.

[5] The hydrophilic resin having thermoplasticity is
The inkjet recording material according to [1] or [2], which is a polymer resin containing at least an oxyalkylene group.

[6] The hydrophilic resin having thermoplasticity is
The inkjet recording material according to [1] or [2], which is a polymer resin containing at least an ethylene oxide unit.

[7] The support is a sheet-like support in which a paper base is coated with a resin composition containing a polyolefin resin [1], [2], [3], [4], [5] or [6]. ]
The inkjet recording material described.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the ink jet recording material of the present invention, for example, a melt of a resin composition having thermoplasticity is applied to the surface of a support by an extrusion coating method, and the applied molten resin composition layer is rotated. It is obtained by cooling and solidifying while pressing against the peripheral surface of the cooling roll.

Conventionally, a hydrophilic resin such as polyvinyl alcohol, which has been prepared in the ink recording layer of an ink jet recording medium alone or as an aqueous paint blended with an absorptive inorganic pigment, can be applied by water, but by a melt extrusion method. I can not use it. Because the conventional hydrophilic resin has a melting point of 23
Although it has thermoplasticity at about 0 ° C., it is easily decomposed by heat and there is nothing that exhibits appropriate fluidity in an extruder, and melt extrusion coating could not be performed. However, in the present invention, a hydrophilic resin having thermoplasticity that does not cause thermal decomposition even at about 200 ° C. is used,
Similar to polyethylene and the like, an ink recording layer is provided by melt molding with an extruder to obtain high glossiness and image sharpness.

The resin composition mainly composed of the hydrophilic resin having thermoplasticity is melt-processed at 150 to 300 ° C., more preferably 180 to 220 ° C. If this temperature is lower than 180 ° C., the fluidity in the melt extruder and the spreadability of the sheet-like melt will be poor, and the adhesion to the support will be weak, making it unsuitable for processing. Further, if the temperature is higher than 220 ° C, the resin may be decomposed in some cases. The melting point of the hydrophilic hydrophilic resin used in the present invention (JIS
K 7121) is not particularly limited as long as melt extrusion coating can be performed, but 210 ° C. or lower is preferable. The melt flow rate (MFR, J of the hydrophilic resin having thermoplasticity of the present invention)
ISK 7210) has a temperature of 190 ° C and a load of 2160g.
In 1 to 50 g / 10 min, the preferred range is 2 to
It is 20 g / 10 min. If the MFR is small, the torque of the melt extruder may become excessive, or the resin may be thermally deteriorated. Also, if it is big,
The amount of the extruded resin becomes unstable, which may cause inconvenience such as hindering stable operation. The density of the hydrophilic resin having thermoplasticity is not particularly limited, but the density is 0.7 to 1.5.
It is about g / cm ³ .

The thermoplastic hydrophilic resin of the present invention is
As long as the hydrophilic resin is suitable for melt extrusion coating and can absorb the ink for ink jet recording, one kind or two or more kinds thereof can be appropriately selected and used.
For example, a copolymer resin containing an ethylene unit and a vinyl alcohol unit can be used. Ethylene-vinyl alcohol copolymer (EVOH) or ethylene-vinyl acetate-vinyl alcohol acetal copolymer resin is preferable. The molar ratio of each unit of these copolymer resins is not particularly limited. The molar ratio of the ethylene unit may be such that the plasticity is exerted at the melt extrusion temperature and the ink absorbability as the ink recording layer is exerted, but it is preferably 25 to 90 mol%. Alternatively, a copolymer resin containing at least a vinyl acetate unit, a vinyl alcohol unit, and an ethylene group having a hydrophilic group in its side chain can be used. For example, a copolymer represented by the following formula, that is,-(CH ₂ -CHO)
H) _l- [CH ₂ -CH (CH ₃ OCO)] _m- (CH ₂ -CHR
¹ ) _n- [wherein R ¹ is a hydrogen atom or an alkyl group, or a hydrophilic group (for example, a carboxyl group, an acetoacetyl group,
Hydrophilic groups such as amino groups and sulfone groups, or alkyl groups substituted with these hydrophilic groups), l, m, n are integers of 1 or more].

It is also possible to use a polymer resin containing at least an oxyalkylene group. For example,
Oxyalkylene group-containing polyvinyl alcohol-based polymer represented by the following formula, ^{i.e., - (CHR 2 -CHR 3 -O} )
_p- H [wherein R ² and R ³ are a hydrogen atom or an alkyl group (especially a methyl group or an ethyl group), p is an integer] and an ethylenically unsaturated monomer containing an oxyalkylene group and vinyl acetate Saponified polymers are useful.

Specific examples of the ethylenically unsaturated monomer containing an oxyalkylene group include polyoxyethylene (meth) acrylate and polyoxypropylene (meth).
Acrylate, polyoxyethylene (meth) acrylamide, polyoxypropylene (meth) acrylamide, polyoxyethylene (1- (meth) acrylamide-1,1-dimethylprepyl) ester, polyoxyethylene (meth) allyl ether, poly Examples thereof include oxypropylene (meth) allyl ether, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether and the like. P indicating the number of moles of oxyalkylene units added
Is about 2 to 300 in each case, and particularly p is 5
About 200 is preferable. Among the above, polyoxyethylene allyl ether, polyoxypropylene allyl ether, polyoxyethylene methallyl ether, polyoxypropylene methallyl ether, and the like have good thermoplasticity and ink absorbability and are highly practical. Alternatively, a polymer resin containing at least ethylene oxide can be used.

These are, for example, the trademark "Eval" (ethylene vinyl alcohol copolymer resin) from Kuraray Co., Ltd. and the trademark "Unitika Resin U" from Unitika Kasei.
MR "(saponified ethylene vinyl acetate copolymer) or trademark" Soarnol "from Nippon Synthetic Chemical Industry Co., Ltd.
(Ethylene vinyl alcohol copolymer resin) can be selected from the commercially available products and used. Also, Kuraray Co., Ltd., trademark: "Kuraray Poval CP series" (modified polyvinyl alcohol), or Nippon Synthetic Chemical Industry Co., Ltd., trademark: "Ecomaty" (modified polyvinyl alcohol) are suitable for melt extrusion coating. It has suitable thermoplasticity and hydrophilicity suitable for ink absorption,
It can be preferably used. Sumitomo Seika Co., Ltd.
A trade name: "Aqua Coke" (ethylene oxide polymer) or a trade name: "PAOGEN" (ethylene oxide polymer) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. can also be used.

The resin composition comprising the hydrophilic resin having thermoplasticity of the present invention may be appropriately mixed with a general-purpose resin, a natural polymer material, a pigment and the like, if necessary. The blending amount of the general-purpose resin or the natural polymer material is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the hydrophilic resin having thermoplasticity. Blending can improve the melt fluidity of the resin composition, and has the effect of improving the melt extrusion processability. Further, the amount of the pigment is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the hydrophilic resin having thermoplasticity.

As the additive, one or more selected from dyes, fluorescent dyes, color pigments, antioxidants, ultraviolet absorbers, antistatic agents, cross-linking agents, water-proofing agents, cationic resins and the like are selected. , Small amounts can be added. General-purpose resins that can be mixed include polyethylene, polypropylene,
Polymethylpentene, polybutene, crystalline polybutadiene, polybutadiene, polystyrene, styrene-butadiene resin, polyvinyl chloride, polyvinyl acetate, polymethylmethacrylate, polyvinylidene chloride resin, polytetrafluoroethylene, ethylene polytetraethylene copolymer, ethylene acetic acid Vinyl copolymer, AS resin, ABS
Resin, ionomer, AAS resin, ACS resin, polyacetal resin, polyamide resin, polycarbonate resin, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyarylate,
Examples thereof include polysulfone, polyether sulfone, polyimide, polyamideimide, polyphenylene sulfimide, cellulose acetate, cellulose acetate butyrate, celluloid, cellophane and nylon.

As the natural polymer material, starch-based polymer,
Examples include cellulose-based polymers, other saccharide-based polymers, protein-based polymers and the like. Corn starch, potato starch, sweet potato starch, rice starch, bean starch, physically modified starch,
Examples thereof include enzyme-modified starch, chemically-modified starch, chemically-degraded starch, esterified starch, and cross-linked starch. Examples of the cellulosic polymer include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, carboxymethyl cellulose, acetyl cellulose and the like. Other other saccharide-based polymers include glycogen, xylan, chitin, chitosan, alginic acid, sodium alginate, guar gum,
Examples include gum, futon, agar and the like. Examples of protein-based polymers include gelatin, collagen such as glue,
Examples include casein, zein, gluten, blood albumin, soybean protein, pullulan and the like.

As the pigment, amorphous silica, vapor phase synthetic silica, synthetic fine particle silica, synthetic fine particle alumina silicate, kaolin, clay, calcined clay, magnesium sulfate, aluminum oxide, aluminum hydroxide, calcium carbonate, satin white, colloidal Silica, anionic colloidal silica, cationic colloidal silica, alumina sol, pseudo-boehmite alumina sol, aluminum silicate, smectite, zeolite, diatomaceous earth, montmorillonite group minerals, hydrotalcite group minerals, smectite group minerals, bentonite group minerals, plastic pigments, grain starch Particles and the like can be appropriately selected and used alone or in combination. The ink recording layer made of the resin composition formed on the support is not particularly limited, but is melt extrusion coated at a coating amount of 10 to 100 g / m ² . If the coating amount is small, the film-forming stability of the molten resin composition and the adhesiveness to the support may be poor, and conversely, if the coating layer is thick, the ink absorbency is improved, but even if it is large, Not only the above effect cannot be expected, but also the recording material becomes thick, or the cost becomes unnecessarily high and it becomes unpractical. It is preferably 20 to 60 g / m ² in view of the balance with the ink absorbability.

Further, for the purpose of strengthening the adhesion between the resin composition and the sheet-like support, an anchor treatment by chemical coating is applied to the surface of the support, corona discharge treatment, flame treatment, low temperature plasma treatment, etc. Surface activation treatment can also be performed. It is also possible to spray the ozone-containing gas onto the surface of the resin melt discharged from the melt extruder on the side in contact with the sheet-shaped support, and then apply the gas onto the support, if necessary. For the support, fine paper, coated paper,
Although a sheet-shaped support such as synthetic paper, polymer film or resin-coated paper can be used, a primer treatment can be performed to further improve the adhesiveness to the ink recording layer.

In the embodiment using a resin-coated paper in which the surface of the paper substrate (or the front surface and the back surface) is coated with the polyolefin resin-containing resin composition as the support, higher gloss and image clarity can be obtained. Also, the adhesiveness between the resin composition containing a hydrophilic hydrophilic resin and the support is good. The polyolefin resin used for coating one or both sides of the sheet-like substrate is a homopolymer of ethylene, α-olefins such as propylene, a copolymer of two or more of the above olefins, and various polymers thereof. Can be selected from a mixture of two or more of Particularly preferred polyolefin resin is low density polyethylene,
High density polyethylene, linear low density polyethylene, and mixtures thereof. The molecular weight of these polyolefin resins is not particularly limited, but is usually 20,000 to 2
Those in the range of 0,000 are used. The coating amount of each of the front and back coating layers is 10 to 40 g / m ² and is formed on the sheet substrate.

The resin composition used for the coating layer includes
Various additives such as a white pigment, a blue pigment, a fluorescent whitening agent, an antioxidant, a fluorescent dye, and a lubricant may be added for the purpose of improving performances such as required whiteness, color tone, and hiding power. Further, the polyolefin resin coating layer on the back surface side may be matted. Further, a back coat layer may be provided on the surface of the back side coating layer for the purpose of imparting antistatic property and printing writability. The coating of the polyolefin resin can be performed by a melt extruder.

The melt extrusion apparatus of the present invention used in the step of coating the resin composition on the paper substrate and the step of coating the support with the ink recording layer includes a melt extrusion machine (extrusion coating apparatus) generally called a laminator. ) Can be used. The laminator is a thermoplastic resin composition (for example, an ink-receiving layer) that flows down in a film shape through an extruder and a T-die, is coated on a support, and is adhered to it. A metal cooling roll and rubber-lined pressure are applied. The operation of pressure bonding cooling is performed with the roll. Alternatively, a cooling roll provided with peelability can be used. The thermoplastic resin composition is supplied from an extruder hopper, passes through a cylinder, is melted and homogenized, reaches a T die through a screen and a breaker plate, and flows down widely. The molten resin spreads from the center of the die to the left and right, forming a thin film of molten resin. The film of the molten resin is sent from the payout part, dropped on the surface of the sheet-like substrate which has been subjected to surface treatment as needed, and is cooled at the same time as being bonded by a cooling roll and a pressure roll and wound on a winder. The thickness of the coating layer is adjusted by the discharge amount of resin, the take-up speed, and the lip of the T-die. In the inkjet recording sheet of the present invention, a polyolefin resin coating layer and an ink recording layer can be simultaneously coated on a paper substrate by using a co-extrusion laminating method.

Another ink recording layer (such as a layer containing a pigment and an adhesive, a resin layer, etc.) may be provided on the ink recording layer specific to the present invention.

[0030]

The present invention will be further described with reference to the following examples. Example 1 Both sides of a paper base having a basis weight of 175 g / m ² and a tenacity of 1.0 g / cm ³ were subjected to corona treatment, and the recording layer side surface contained 10% by weight of titanium dioxide mixed and dispersed in advance with a Banbury mixer. The polyolefin resin composition for surface 1 having the following composition was applied to a coating amount of 30 g / m ² using a melt extruder having a T-type die (melting temperature 3
20 ° C.), at this time, the surface of the cooled surface coating layer was made highly smooth by using a mirror-finished cooling roll. On the opposite side, a backside polyolefin resin composition 1 having the following composition was applied at a coating amount of 25
It is coated with a melt extruder having a T-die (melting temperature 320 ° C.) so as to be g / m ² , and its surface is first sandblasted with 120-mesh sand powder, and then chrome-plated. The backside coating layer cooled using a cooling roll having a surface shape that was applied and finished was made to have a matte surface so that a sheet-shaped support was obtained.

Surface Polyolefin Resin Composition 1 Low Density Polyethylene Resin (Trademark: Sholex L-1
82, Showa Denko KK, density 0.919, melt flow ratio 8 g / 10 min) 60 parts by weight, high density polyethylene resin (trademark: Sholex L-191, Showa Denko KK, density 0.935 g / cm ³ , melt flow ratio 11 g / 10 min) 30 parts by weight, anatase titanium dioxide (manufactured by Ishihara Sangyo, trademark: A-220)
10 parts by weight, zinc stearate 0.1 parts by weight, antioxidant (Ciba Geigy, Irganox 1010)
05 parts by weight, ultramarine blue (trade name: blue mouth ultramarine blue manufactured by Daiichi Kasei)
o. 2000) 0.01 part by weight.

Polyolefin resin composition for back side 1 High-density polyethylene resin (trademark: Shorex L-1
91, Showa Denko KK, density 0.935 g / cm ³ ,
Melt flow ratio 11g / 10min) 65 parts by weight, low density polyethylene resin (trademark: Shorex L
-170, Showa Denko KK, density 0.917 g / cm
³ , melt flow ratio 7g / 10min) 35 parts by weight.

Next, after corona discharge treatment was applied to the surface of the surface side polyethylene resin coating layer of the above support, a polyvinyl alcohol derivative containing an oxyalkylene group as a thermoplastic hydrophilic resin (Kuraray Co., Ltd., trademark: CP-10
00, melt flow ratio (MFR) 2g / 10mi
n, density 1.25 g / cm ³ , melting point 174 ° C.), melting temperature 190 ° C., processing speed 20 m / min, coating amount 50 g
Simultaneously with the melt extrusion coating at / m ^2, and cooled using cooling rolls subjected to mirror finishing to form a polyvinyl alcohol layer having a specular gloss.

Example 2 The surface of a polyethylene resin-coated paper prepared in the same manner as in Example 1 was subjected to corona discharge, and then a vinyl acetate unit, a vinyl alcohol unit, and hydrophilic groups were added to the side chains as a thermoplastic hydrophilic resin. Modified polyvinyl alcohol having a structure having an ethylene unit (trade name: Ecomaty AX2000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., melt flow rate (MFR) 20 g / 10 min, density 1.2)
7 g / cm ³ , melting point 199 ° C.) at a melting temperature of 220 ° C., a processing speed of 20 m / min, and a coating amount of 40 g / m ² by melt extrusion coating, and at the same time, cooling using a cooling roll having a mirror finish, An ink recording layer having a specular gloss was formed.

Example 3 After corona discharge was applied to the surface of a paper substrate having a basis weight of 175 g / m ² and a tenacity of 1.0 g / cm ^3, a modified polyvinyl alcohol (made by Kuraray Co., Ltd.) was used as a thermoplastic hydrophilic resin. , Trademark: CP-2000, Melt Flow Rate (MFR) 2
g / 10 min, density 1.24 g / cm ³ , melting point 130
℃), melting temperature 180 ℃, processing speed 20m / min,
At the same time as melt extrusion coating with a coating amount of 20 g / m ² ,
It cooled using the cooling roll which gave the mirror surface finish, and formed the ink recording layer with a mirror surface gloss.

Example 4 Preparation of Resin Composition Polyoxyethylene allyl ether having an addition mole number of oxyethylene of about 25 and vinyl acetate were copolymerized in methanol in the presence of azobisisobutyronitrile as a catalyst, 20% by weight of polyoxyethylene (meth) allyl ether unit and 80% by weight of vinyl acetate unit
Was obtained. Then, it was saponified by a conventional method to obtain an oxyethylene group-containing vinyl alcohol polymer having a saponification degree of the vinyl acetate component of 93 mol%. This copolymer has a melt flow rate of 15 g / 10 min and a density of 1.15.
It was g / cm ³ and the melting point was 200 ° C. Then, the powder of the oxyethylene group-containing vinyl alcohol polymer is dried to a water content of 0.1% by weight or less, and the ink recording layer composition having the following formulation is premixed with a Banbury mixer, and then biaxial extrusion is performed. It was mixed and dispersed by a machine, extruded linearly, and pelletized.

Recording Layer Formulation The above-mentioned oxyethylene group-containing vinyl alcohol polymer 1
00 parts by weight, low density polyethylene (Mitsui Petrochemical Industry Co., Ltd., trademark: Mirason M-14P, density 0.91)
9, melt flow ratio 5.1g / 10min, melting point 1
2 parts by weight, fine silica (average particle diameter 1.5 μ)
m) 2 parts by weight, corn starch 2 parts by weight, glycerin 5
Parts by weight

Then, after corona discharge was applied to the surface of the polyethylene resin-coated paper prepared in the same manner as in Example 1, the above ink recording layer composition was melted at 220 ° C., processing speed was 20 m / min, and coating was performed. The melt-extrusion coating was performed at an amount of 40 g / m ² , and at the same time, cooling was performed by using a cooling roll having a mirror finish to form an ink recording layer having a mirror gloss.

Example 5 A corona discharge was applied to the surface of a paper substrate having a basis weight of 107 g / m ² and a tenacity of 0.75 g / m ³ and then a polymer resin containing polyethylene oxide as a thermoplastic resin (Daiichi Kogyo). (stock)
Made, trademark: Paogen PP-15, melt flow ratio (MFR) 30 g / 10 min, density 1.07 g / cm
³ , melting point 55 ℃) melting temperature 150 ℃, processing temperature 10m
/ Min at a coating amount of 20 g / m ² for melt extrusion, and at the same time, cooling was performed using a mirror-finished cooling roll to form an ink recording layer having a mirror gloss.

Example 6 After corona discharge was applied to the surface of a paper substrate having a basis weight of 104 g / m ² and a tenacity of 0.85 g / m ^3, an ethylene vinyl alcohol resin (manufactured by Kuraray Co., Ltd.) was used as a thermoplastic resin. Trademark:
Eval EP-H105, melt flow ratio (MF
R) 5.5 g / 10 min, density 1.14 g / cm ³ ,
Melting point 165 ° C.) melting temperature 230 ° C., processing temperature 10 m /
The coating was performed by melt extrusion at a coating amount of 20 g / m ² for min, and at the same time, cooling was performed using a cooling roll having a mirror finish to form an ink recording layer having a mirror gloss.

Comparative Example 1 Commercially available glossy paper for ink jet recording (trade name: GP-101 manufactured by Canon Inc.) containing an absorbing inorganic pigment and a binder component and provided with an ink recording layer having a surface smoothed. .

Comparative Example 2 Polyethylene resin coated paper prepared in the same manner as in Example 1
After applying corona discharge to the surface of the
The recording layer is prepared with water-based paint, and the coating amount is 12 g / m ^Twobecome
As described above was applied by the bar coat method.Ink recording layer prescription Completely saponified poly vinyl alcohol (Kuraray Co., Ltd.
Standard: Kuraray Poval 117) 93 parts by weight, cross-linking agent
(Co., Ltd., Showa Denko, trademark: Papirole J-003)
7 parts by weight

Comparative Example 3 Polyolefin resin coating prepared in the same manner as in Example 1
Used in Example 1 after corona discharge on paper surface
Coating amount by dissolving hydrophilic thermoplastic resin with water
15 g / m^TwoWas applied by the bar coating method.
That is, modified polyvinyl alcohol (Nihon Gosei Kabushiki Kaisha)
Gaku Kogyo, Trademark: Ecomaty AX2000, Melt Flow
-Rate (MFR) 20g / 10min, density 1.27
g / cm ^Three, Melting point 199 ° C.) and the concentration becomes 20% by weight.
To prepare a paint.

Comparative Example 4 After corona discharge was applied to the surface of a paper substrate having a basis weight of 175 g / m ² and a tenacity of 1.0 g / cm ^2, a low density polyethylene resin (Mitsui Petrochemical Industry Co., Ltd.) was used as a thermoplastic resin. Made, trademark: Mirason M-11P, melt flow rate (MF
R) 7.2 g / 10 min, density 0.917 g / c
m ³ , melting point 106 ° C.), melting temperature 260 ° C., processing speed 2
Melt extrusion coating was performed at 0 m / min and a coating amount of 30 g / m ² , and at the same time, cooling was performed using a cooling roll having a mirror finish, to obtain a mirror glossy surface.

Evaluation The glossiness, the image clarity, and the solid portion of the ink jet recording material of each comparative example after printing and recording with a commercially available ink jet printer (manufactured by Hewlett Packard, trademark: Deskjet 560J) Gloss, image clarity, and ink absorbency were evaluated by the following methods. (1) Glossiness JIS-Z-8741 is applied to solid portions and white portions colored with yellow, magenta, and cyan color inks.
In accordance with the method described above (specular gloss of 60 ° incident angle and 60 ° incident angle), a gloss meter (trademark: manufactured by Nippon Denshoku Industries Co., Ltd .:
It measured by VG-10) and averaged the measured value of 5 times.

(2) Image sharpness JIS-K-7105 is applied to solid portions and white portions colored with yellow, magenta and cyan color inks.
Among the image sharpness defined by the above, the value when an optical comb width of 2 mm was used was measured, and the measured values of 5 times were averaged.

(3) Ink Absorbency The ink absorptivity was evaluated by pressing high-quality paper against the printed solid portion and measuring the time until the ink transferred to the high-quality paper was no longer recognized. Evaluation was made in three stages (◯: 7 seconds or less, Δ: 7 to 15 seconds, x: 15 seconds or more).
Table 1 shows the evaluation results.

[0048]

[Table 1]

The ink jet recording sheets of Examples 1 to 6 according to the present invention have good ink absorbency, glossiness,
Although the image definition was excellent, the ink jet recording sheet of Comparative Example 1, which was out of the range of the present invention, had low gloss before and after ink recording and image sharpness. The ink jet recording sheet of Comparative Example 2 had insufficient ink absorbency.
A coating layer having exactly the same composition as that of the present invention is applied as an aqueous paint.
In Comparative Example 3 obtained by drying, the glossiness and image clarity of the white paper portion were low, and the coating amount could not be increased to more than 15 g / m ² by the water-based coating, so the ink absorbency was also poor. In Comparative Example 4, since the recording layer was formed using a general-purpose thermoplastic resin having no hydrophilicity, the ink absorbability was extremely poor, and print recording could not be performed at all.

[0050]

INDUSTRIAL APPLICABILITY The ink jet recording sheet of the present invention has excellent ink absorbency and high gloss by forming a resin composition containing a hydrophilic hydrophilic resin as an ink recording layer by a melt extrusion coating method. A recorded image having a degree and image clarity can be obtained, which is extremely useful in practice.

Claims (7)

[Claims] 1. An inkjet recording body having an ink recording layer on a support, wherein the ink recording layer is made of a resin composition containing a hydrophilic resin having thermoplasticity, and the ink recording layer is formed by a melt extrusion coating method. An inkjet recording material characterized by the above. 2. The melting point of the hydrophilic resin having thermoplasticity is 2.
The ink jet recording material according to claim 1, wherein the melt flow ratio (temperature 190 ° C., load 2160 g) is 1 to 50 g / 10 minutes at 10 ° C. or less. 3. The ink jet recording material according to claim 1, wherein the hydrophilic resin having thermoplasticity is a copolymer resin containing at least an ethylene unit and a vinyl alcohol unit. 4. The hydrophilic resin having thermoplasticity is a copolymer resin containing at least a vinyl acetate unit, a vinyl alcohol unit and an ethylene unit having a hydrophilic group in a side chain. Item 2. The inkjet recording material according to item 2. 5. The ink jet recording material according to claim 1 or 2, wherein the hydrophilic resin having thermoplasticity is a polymer resin containing at least an oxyalkylene group. 6. The inkjet recording material according to claim 1, wherein the hydrophilic resin having thermoplasticity is a polymer resin containing at least an ethylene oxide unit. 7. The ink jet recording material according to claim 1, wherein the support is a sheet-like support in which a polyolefin resin-containing resin composition is coated on a paper base.