JPH10181184A - Ink jet recording medium and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a recording medium having excellent glossiness and ink absorptivity by coating to form a porous recording layer on a molding surface, then directly press-bonding the recording layer to a lower layer of a support having a lower layer containing resin having affinity with water or polyhydric alcohol as a main component, and releasing the molding surface. SOLUTION: At least one lower layer containing resin having affinity with water or polyhydric alcohol as a main component and at least one upper layer having a porous upper layer are formed on a support, the porous upper layer is coated to be formed on a molding surface, then transferred to the lower surface, and the molding surface is released. The porous upper layer contains fine particles each having a mean particle size of 10 to 300nm. The porous recording layer coating the molding surface and the resin layer having affinity with water or polyhydric alcohol are superposed and controlled at suitable temperature and pressure. Then, adhesive force between the recording layer and the resin layer becomes larger than that of the molding surface and the recording layer to obtain an excellent recording layer.

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 medium having excellent ink absorbency and printing density and having high gloss, and a method for producing the same.

[0002]

2. Description of the Related Art An ink jet recording system is a system in which ink droplets ejected from a nozzle at a high speed are adhered to a recording material for recording, and has features such as easy full-color printing and low printing noise. . In this method, since the ink used contains a large amount of solvent, it is necessary to use a large amount of ink in order to obtain a high recording density. In addition, since the ink droplets are continuously ejected, the next droplet is ejected before the first droplet is absorbed, which is likely to cause a disadvantage that the ink droplets are fused and ink dots are joined. Therefore, the recording medium used in the ink jet recording method has a high print dot density, a bright and vivid color tone, and has a high ink absorption, and does not have ink bleeding even when the print dots overlap. Etc. are required. In recent years, in response to the rapid spread of inkjet printers, in the printing field, high-gloss photographic prints have been required for various publications and packaging applications.

[0003] In general, inks for ink-jet recording systems are composed of water, organic solvents, dyes, additives and the like. Since the amounts of water and the organic solvent occupy 80% or more, the ink jet recording medium needs to have water absorbency and solvent absorbability. In general, commercially available inkjet paper is composed of a pigment having pores (several μm order) and a binder, and the pigment used is large. Therefore, in order to maintain the transparency of the recording layer, it is necessary to suppress the coating amount considerably. there were. If the coating amount is small, the ink absorption capacity becomes insufficient, the ink overflows from the surface, and the phenomenon of blurring occurs. When the coating amount is increased, the smoothness and glossiness of the surface of the recording layer are not sufficient, and the print density is lowered.

Therefore, the inventors provided an intermediate layer having adhesiveness or tackiness on a support, coated a recording layer mainly composed of a transparent pigment (colloidal silica, alumina sol, etc.) on the molding surface, and formed a film. A manufacturing method in which a recording layer and an intermediate layer are overlapped and a molding surface is peeled off has been proposed (Japanese Patent Application No. 7-212105, Japanese Patent Application No. 7-311909). Although it is possible to obtain a high gloss by this, the polymer resin or resin latex, which is generally called an adhesive or pressure-sensitive adhesive, has insufficient affinity with the ink and does not have ink absorbency. If the amount of ejected ink is large, it is necessary to apply a large amount of recording layer to completely absorb the ink. For this reason, there have been problems such as cracking of the coating film, lowering of the transparency of the recording layer, lowering of the printing density and increasing of the price.

[0005] For the purpose of imparting gloss, there have been reported many ink jet recording materials coated with a resin having an affinity for water or a polyhydric alcohol which absorbs ink by dissolution and swelling (Japanese Patent Publication No. 62-55995, Tokuhei 4-3
4954, Tokuhei 5-26654, etc.). The recording layer made of a resin having an affinity for water or a polyhydric alcohol has high transparency and is widely used as an OHP. Further, since a high print density is easily obtained, it is also commercially available as a glossy inkjet recording medium. However, since the recording layer absorbs ink by dissolution and swelling,
There is a problem that the ink easily spreads, the drying speed of the ink is low, the recording surface is sticky for a long time after printing, and it is difficult to handle. Furthermore, there were problems that the recording layer was insufficiently water-resistant, resulting in blocking under high humidity, and that the recorded image was blurred due to adhesion of water droplets or sweat.

In order to solve the above-mentioned problem, there has been a proposal to provide a porous layer as an ink passage layer on a resin recording layer having an affinity for water or a polyhydric alcohol (Japanese Patent Application Laid-Open No. 61-158495; JP-A-62-264986). The provision of the ink permeable layer improves the ink absorption speed, ink absorption capacity, ink fixability, and anti-blocking property. However, any of these ink passage layers is directly on a resin recording layer having an affinity for water or a polyhydric alcohol. Therefore, the resin recording layer having an affinity for water or a polyhydric alcohol once dissolves or swells and then re-forms a film, so that the surface of the ink passage layer tends to be uneven and a smooth surface cannot be obtained. For this reason, it was difficult to obtain a glossy recording layer surface. Further, when drying the ink-passing layer, there is a problem that the surface of the ink-passing layer is liable to crack because the resin layer having an affinity for water or polyhydric alcohol and the ink-passing layer have different shrinkage rates due to drying. Was.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides an ink jet recording medium which is more excellent in glossiness and ink absorbability and provides a high print density, or a transparent type ink jet recording medium for OHP. provide.

[0008]

After forming a porous recording layer on a molding surface by coating, the porous recording layer has a lower layer mainly composed of a resin having an affinity for water or a polyhydric alcohol. It was found that when an ink jet recording material was manufactured by directly pressing the lower surface of the support and peeling off the molding surface, an ink jet recording material having high gloss, high print density, and high ink absorbability was obtained. A resin having an affinity for water or a polyhydric alcohol used in a recording layer of a transparent type ink jet recording medium (for OHP or the like) has poor adhesiveness and tackiness. However, the inventors of the present invention have conducted intensive studies, and as a result, a porous recording layer coated on the molding surface and a resin layer having an affinity for water or a polyhydric alcohol are laminated, and if the temperature and pressure are appropriately controlled, the porous recording layer becomes porous. The adhesive force between the hydrophilic recording layer and the resin layer having an affinity for water or polyhydric alcohol can be controlled to be greater than the adhesive force between the molding surface and the porous recording layer, and an excellent ink jet recording body can be obtained. By this method, an OHP for inkjet recording having excellent transparency can also be manufactured. In the present invention, since the porous recording layer (upper layer) is formed and then transferred onto a resin recording layer having an affinity for water or a polyhydric alcohol, there is no fear that the porous recording layer is cracked. In general, when a porous recording layer is provided on a resin recording layer having an affinity for water or a polyhydric alcohol, overcoating is performed. Alternatively, the resin layer having an affinity for the polyhydric alcohol and the ink-passing layer have different shrinkage ratios due to drying, and thus the surface of the ink-passing layer is apt to crack. However, according to the present invention, the above problem can be solved. In the present invention, by changing the molding surface, it is also possible to obtain an ink jet recording medium having a high print density such as matte tone and high ink absorbency.

In the present invention, in order to obtain a high printing density, it is preferable to make the porous recording layer as transparent as possible. When fine particles having an average particle diameter of 10 to 300 nm are used as the pigment for the porous recording layer, the transparency of the porous recording layer is good, and an ink jet recording body having a higher printing density can be obtained. The present invention includes the following embodiments. [1] In an ink jet recording medium comprising at least one lower layer mainly composed of a resin having an affinity for water or a polyhydric alcohol on a support and at least one upper layer having a porous upper layer, After the upper layer having the property is coated on the molding surface, it is transferred to the lower layer, the molding surface is peeled off, and the porous upper layer contains fine particles having an average particle diameter of 10 to 300 nm. An ink jet recording medium characterized by the following. [2] The ink jet recording medium according to [1], wherein the resin having an affinity for water or a polyhydric alcohol is a resin having an ink absorbency. [3] The ink jet recording material according to [1] or [2], wherein the resin having an affinity for water or a polyhydric alcohol is at least one selected from partially saponified polyvinyl alcohol and polyvinylpyrrolidone.

[4] The ink jet recording material according to [1], wherein the fine particles are secondary particles. [5] The ink jet recording medium according to [4], wherein the porous upper layer contains secondary particles having an average particle diameter of 10 to 300 nm and a water-soluble resin. [6] The ink jet recording material according to any one of [1] to [5], wherein the porous upper layer contains a cationic substance. [7] The ink jet recording medium according to any one of [1] to [6], wherein the lower layer mainly composed of a resin having an affinity for water or a polyhydric alcohol contains a cationic substance.

[8] An ink jet recording medium comprising a support having at least one lower layer mainly composed of a resin having affinity for water or a polyhydric alcohol, and at least one upper layer having a porous upper layer. In the manufacturing method, after the upper layer having a porous film is coated on the molding surface,
A method for producing an ink jet recording medium, wherein the method is characterized by being transferred to the lower layer and peeling off the molding surface, and wherein the porous upper layer contains fine particles having an average particle diameter of 10 to 300 nm. [9] The method of [8], wherein the molding surface is a polymer film or a metal surface.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the support is not particularly limited. For example, plastic films such as cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, polyester, etc., high quality paper, art paper , Coated paper, cast coated paper, foil paper, kraft paper, polyethylene laminated paper, impregnated paper, evaporated paper,
Paper such as water-soluble paper, metal foil, synthetic paper, and the like are appropriately used.

Materials used for the molding surface include cellophane having high surface smoothness, plastic films such as polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, polyester, etc., polyethylene laminated paper, glassine paper, impregnation. Papers such as paper and vapor-deposited paper, flexible sheets such as metal foil and synthetic paper, and drums and plates having a highly smooth surface such as inorganic glass, metal and plastic are appropriately used. In particular, from the viewpoint of the manufacturing process and the suitability for peeling the molded surface and the recording layer, etc., a polymer film (polyethylene, polypropylene, polyester, etc.)
Metal drums having a high smooth surface are preferred. The molded surface is preferably smooth for the purpose of imparting gloss, and the surface roughness (JISB 0601) of the molded surface is such that Ra is 0.5 μm.
m is preferable, and Ra is more preferably 0.05 μm
It is as follows. The surface roughness can be controlled to give a texture such as semi-gloss tone or matte tone.

The molding surface may be left untreated. However, in order to control the adhesive force between the molding surface and the recording layer to be smaller than the adhesive force between the recording layer and the support (or another recording layer), the coating on the molding surface is controlled. It is possible to apply a compound having releasability such as silicone or fluororesin on the surface to be used. Next, the lower layer of the present invention will be described. The lower layer contains water or a resin having an affinity for polyhydric alcohol as a main component, and is preferably contained in an amount of 70% by weight or more, more preferably 80% by weight or more. Examples of the resin constituting the resin recording layer having an affinity for water or a polyhydric alcohol include polyvinyl alcohol (including various modified polyvinyl alcohols), polyvinyl pyrrolidone, casein, starch, starch derivatives, water-soluble cellulose derivatives, polyacrylic acid, Various known materials such as sodium polyacrylate, polyacrylamide, polyethylene oxide, polyethylene glycol, polyvinyl methyl ether, gelatin and the like can be mentioned. In order to obtain ink absorbency, particularly ink absorption speed, partially saponified polyvinyl alcohol (degree of saponification 95% or less, preferably 90% or less) or polyvinylpyrrolidone is preferred.

For the purpose of improving the water resistance of the resin recording layer having an affinity for water or a polyhydric alcohol, a generally known water-proofing agent may be added. Examples of the water-proofing agent include an aldehyde compound, a melamine compound, an epoxy compound, a urea resin, an isocyanate, and a polyethyleneimine compound. The addition number of the water-proofing agent is 0.1 parts per 100 parts of the resin.
A range of from 10 to 10 parts is preferred. Of course, as long as the transparency of the resin recording layer having an affinity for water or polyhydric alcohol is not impaired, water resistance, for the purpose of improving ink absorption, silica, alumina, pseudo-boehmite, calcium carbonate, styrene and the like are known. A small amount of pigment may be blended. However, the lower layer is mainly composed of resin, the pigment is preferably 25 parts by weight or less, preferably 100 parts by weight of the resin,
It is more preferably at most 10 parts by weight.

The coating amount is not particularly limited.
It is preferably adjusted to １００100 g / m ² , preferably 5 to 50 g / m ² . When the amount is small, the ink absorbency is low, and when the amount is large, the effect is saturated and is meaningless. The resin recording layer having an affinity for water or a polyhydric alcohol may be a single layer or a multilayer.

Next, the porous recording layer (also referred to as a porous upper layer) of the present invention will be described in detail. The porous recording layer contains at least a pigment and an adhesive (binder). Examples of pigments include silica, colloidal silica, kaolin, clay, calcined clay, zinc oxide, tin oxide, magnesium sulfate, aluminum oxide, aluminum hydroxide, pseudoboehmite, calcium carbonate, satin white,
Various pigments known in the general coated paper field are appropriately used, such as aluminum silicate, smectite, zeolite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene-based plastic pigment, urea-based plastic pigment, and benzoguanamine-based plastic pigment. . However, in order to improve the smoothness and transferability of the coating layer, the average particle size of the pigment is set to 10 to 300 nm. Further, in order to obtain a high print density, 10 to 300 n
m secondary particles (dispersion) are preferably selected and used. In order to obtain fine particles having an average particle diameter of 300 nm or less, a commercially available synthetic amorphous silica (several microns) can be obtained by applying a strong force by mechanical means. That is, breaki
It can be obtained by the ng down method (a method of subdividing a bulk raw material). Examples of mechanical means include mechanical methods such as ultrasonic waves, high-speed rotation mills, roller mills, container driving medium mills, medium stirring mills, jet mills, grinders, and sand grinders. All the average particle diameters referred to in the present invention are the particle diameters observed with an electron microscope (SEM and TEM) (average Martin diameter; see "Fine Particle Handbook", Asakura Shoten, p. 52, 1991). The secondary particles are 3 to 4
Aggregates of 0 nm primary particles are preferred.

To form a porous recording layer (upper layer),
The addition of an adhesive (binder) is essential. Examples of the adhesive (binder) include water-soluble resins (for example, polyvinyl alcohol, casein, soybean protein, synthetic proteins, starch, cellulose derivatives such as carboxymethylcellulose and methylcellulose), styrene-butadiene copolymer, and methyl methacrylate-butadiene copolymer. Known adhesives generally used for coated paper, such as water-dispersible resins such as coalesced conjugated diene polymer latex, acrylic polymer latex, and vinyl copolymer latex such as styrene-vinyl acetate copolymer (Binder) is used alone or in combination. In order to increase the adhesiveness between the porous recording layer and the resin recording layer (lower layer) having an affinity for water or a polyhydric alcohol, a water-soluble resin is preferably used as the adhesive for the upper layer. More preferably, completely saponified (saponification degree: 98% or more) polyvinyl alcohol is used.

The weight ratio of the solid content of the pigment and the adhesive (binder) in the porous recording layer is adjusted within the range of 100/2 to 100/200, preferably 100/5 to 100/100. If the amount of the adhesive (binder) is large, the pores between the particles become small, and it is difficult to obtain an ink absorption rate. On the other hand, when the amount of the adhesive (binder) is small, the coating layer is easily cracked. For the ink jet recording medium, a cationic resin can be added to the recording layer for the purpose of improving the ink fixing property. Recording layer of the invention (porous recording layer, resin recording layer having affinity for water or polyhydric alcohol)
A cationic resin may be added thereto for use. Examples of the cationic resin to be added include polyalkylene polyamines such as polyethylene amine and polypropylene polyamine, or derivatives thereof, acrylic resins having a tertiary amino group and a quaternary ammonium group, and diacrylamine. The amount of the cationic resin to be added is adjusted in the range of 1 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts of the pigment. In addition, dispersants, thickeners, defoamers used in general coated paper production,
Various auxiliaries such as a coloring agent, an antistatic agent, and a preservative are appropriately added.

Although the coating amount of the porous recording layer is not particularly limited, it is 1 to 80 g / m ² , preferably ² to 40 g.
/ M ² . If the coating amount is small, it is difficult to obtain a uniform coating film, and if it is large, the effect is saturated, and the coating film is liable to crack. The porous recording layer may be a single layer or a multilayer. As a coating coater for obtaining any recording layer, various known coating apparatuses such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a curtain coater, a die coater and the like. No.

In the ink jet recording sheet of the present invention, a recording layer (lower layer) mainly composed of a resin having an affinity for water or a polyhydric alcohol is provided on a support, and a porous recording layer previously provided on a molding surface is provided. It is manufactured by peeling off the molded surface by pressing. The pressure bonding conditions (temperature, pressure) between the recording layers are such that the adhesive strength between the resin layer (lower layer) having an affinity for water or a polyhydric alcohol and the porous recording layer is larger than the adhesive strength between the molding surface and the porous recording layer. Although not particularly limited, the pressure is preferably adjusted to 40 ° C. or higher and the pressure to 5 kg / cm (linear pressure) or higher. More preferably, the pressing temperature is 50.
The temperature is adjusted to １００100 ° C. and the pressure to 10 kg / cm (linear pressure) or more. As the ink used in the inkjet recording method of the present invention, a dye for forming an image and a liquid medium for dissolving or dispersing the dye are essential components, and various dispersants, surfactants, if necessary, It is adjusted by adding a viscosity adjusting agent, a specific resistance adjusting agent, a pH adjusting agent, a fungicide, a dissolution or dispersion stabilizer of the recording agent, and the like.

Examples of the recording agent used in the ink include direct dyes, acid dyes, basic dyes, reactive dyes, edible dyes, disperse dyes, oil dyes, and various pigments. Can be used without. The content of such a dye is determined depending on the type of the liquid medium component, the characteristics required for the ink, and the like, but in the case of the ink of the present invention, the composition as in the conventional ink, that is, There is no particular problem in use at a ratio of about 0.1 to 20% by weight.

As the solvent of the ink used in the present invention, water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol,
C1-C4 alkyl alcohols such as isopropyl alcohol, n-butyl alcohol and isobutyl alcohol; ketone or ketone alcohols such as acetone and diacetone alcohol; polyethylene glycol, polyalkylene glycols such as polypropylene glycol, ethylene glycol; , Alkylene groups such as propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol, diethylene glycol having 2 to 6 alkylene glycols, amides such as dimethylformamide, ethers such as tetrahydrofuran, glycerin, Multivalent alcohols such as ethylene glycol methyl ether, diethylene glycol methyl (ethyl) ether, and triethylene glycol monomethyl ether Such as a lower alkyl ether of Le and the like.

[0024]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto.
Unless otherwise specified, parts and% in the examples are solid contents excluding water, and represent parts by weight and% by weight, respectively. The coating amount indicates a dry coating amount unless otherwise specified. [Silica sol] Synthetic amorphous silica having an average aggregate particle diameter of 3.0 μm (manufactured by Nippon Silica Industry Co., Ltd., trade name: Nipsil H)
D-2, primary particle size of 11 nm) and then dispersed by a sand grinder, further dispersed by an ultrasonic homogenizer, and the dispersion operation of the sand grinder and the ultrasonic homogenizer was repeated until the average particle diameter of the aggregates became 70 nm. % Aqueous solution was prepared.

The particle size was measured as follows. Dispersion particle size measurement method: TEM (transmission electron microscope, H-3
00, manufactured by Hitachi, Ltd.). Dispersion is 0.
After diluting to 5%, the solution was dropped on a collodion film, air-dried, and used for observation. Electron microscope magnification is 20,000 times, 50,000 times,
I chose from 100,000 times. Example 1 Cation-modified colloidal silica which is a primary particle dispersion having an average particle diameter of 65 nm (manufactured by Nissan Chemical Industries, trade name: ST-AK)
-YL) in 100 parts of silyl-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name: R-2105, degree of polymerization: 50)
0, saponification degree: 98.5%) A molding surface (PET film, manufactured by Toray Industries, Inc., 75 μm, trade name) such that a coating amount of a 20% aqueous solution mixed with 10 parts by a Meyer bar is 5 g / m ^2. Lumirror T, surface roughness Ra = 0.02 μm). Next, polyvinyl alcohol (Kuraray Co., Ltd.
Trade name: PVA-505, degree of polymerization: 500, degree of saponification:
A 74%) 10% aqueous solution was prepared, and a commercially available coated paper (manufactured by Shin-Oji Paper Co., Ltd., trade name: OK coated, 127.9 g / m ² )
(A product obtained by laminating 15 μm of polyethylene on the surface of a coated paper by an extrusion lamination method, hereinafter simply referred to as a laminated coated paper), and then coated and dried so that the coating amount was 15 g / m ² . Subsequently, the coating layers were bonded so that the surfaces faced to each other, pressure-bonded with a calendar having a surface temperature of 50 ° C. and a linear pressure of 20 kg / cm, and the PET film on the molding surface was peeled off, thereby producing an ink jet recording body of the present invention.

Example 2 100 parts of the above-mentioned silica sol having an average particle diameter of agglomerate of 70 nm was mixed with polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name: PV
A-135H, degree of polymerization: 3500, degree of saponification: 99% or more) A molding surface (chromium plating, mirror finish) with a 10% aqueous solution mixed with 40 parts by a Meyer bar so that the coating amount is 5 g / m ^2. Coated on a metal drum having a finished surface, surface roughness Ra = 0.05 μm). Next, Example 1
In the same manner as above, a laminate coated paper surface was coated with polyvinyl alcohol (product name: PVA-505, manufactured by Kuraray Co., Ltd.) and pressurized (temperature: 50 ° C., linear pressure: 20).
kg / cm), and peeled off from the molding surface to produce an ink jet recording medium of the present invention.

Example 3 The aqueous solution of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name: PVA-505) in Example 1 was mixed with polyvinylpyrrolidone (manufactured by BASF, trade name: Rubiscol K-
90, an average molecular weight of about 360,000) 95 parts of an acrylic resin emulsion (manufactured by Johnson Polymer Co., trade name: Joncryl 7001, concentration 42%), except that the coating liquid contained 5 parts of solid content. In the same manner as in Example 1, an ink jet recording medium of the present invention was produced.

Comparative Example 1 Polyvinyl alcohol (Kuraray Co., trade name: PVA)
-505) to prepare a 10% aqueous solution, and the same as in Example 1.
20 g / m coating amount on the surface of the laminated coated paper ^TwoBecomes
The coating was dried as follows. Comparative Example 2 Primary Particle Dispersion Cation-Modified Colloy with an Average Particle Size of 65 nm
Dalsilica (Nissan Chemical Industries, trade name: ST-AK-Y
L) 100 parts of silyl-modified polyvinyl alcohol
(Kuraray Co., trade name: R-2105) 10 parts
20% aqueous solution with a Meyer bar on the surface of laminated coated paper
20g / m coating amount on the surface^TwoAnd dried. Comparative Example 3 Polyvinyl was applied to the laminated coated paper in the same manner as in Example 1.
Of alcohol (Kuraray Co., Ltd., trade name: PVA-505)
A recording layer was provided. Primary particle dispersion having an average particle size of 65 nm
Thion-modified colloidal silica (Nissan Chemical Industries, trade name:
ST-AK-YL) 100 parts, silyl-modified polyvinyl
Alcohol (Kuraray Co., Ltd., trade name: R-2105) 10
Part of a 20% aqueous solution mixed with a
g / m^TwoAnd dried.

Comparative Example 4 Polyvinyl alcohol (Kuraray, trade name: PV) was added to 100 parts of synthetic amorphous silica having an average particle size of 1.5 μm (trade name: Fine Seal-80, manufactured by Tokuyama Corporation).
A-117) After uniformly dispersing 40 parts of a 15% aqueous solution, the mixture was coated on a molding surface (a PET film similar to that in Example 1) and dried by a Meyer bar so that the coating amount was 10 g / m ² . Next, the coated surface and a coated surface of a laminated coated paper coated with polyvinyl alcohol (the above-mentioned trade name: PVA-505) in the same manner as in Example 1 were bonded together, and the surface temperature was 50 ° C. and the linear pressure was 20 kg. / Cm, and the PET film on the molding surface was peeled off to produce an ink jet recording medium.

[Evaluation Methods] Examples 1-4, Comparative Examples 1-3
The ink absorption speed, ink absorption capacity, glossiness, etc. of the ink jet recording material obtained in the above were evaluated by the following methods.
For glossiness and ink absorption, a commercially available inkjet printer (trade name: BJC-600J, manufactured by Canon Inc.)
Indicates the glossiness, ink absorptivity, and print density of the solid portion when recording was performed with.

[Ink Absorption] a. (Ink absorption speed) Printing each single color of yellow, magenta, and cyan, and sticking high quality paper on the printing surface printed every 5 seconds immediately after printing,
Observe whether the ink transfers to woodfree paper. The time until no transfer occurs at all is measured. The measured number of seconds was evaluated in three steps (○: 5 seconds or less, Δ: 5 to 30 seconds, ×: 3
0 seconds or more). b. (Ink absorption capacity) Using an A4 size inkjet recording medium, yellow,
Magenta and cyan colors of 10cm x 10cm square
Continuous solid printing at 20 g / m ² at each location, and to observe whether the ink overflows from the coating layer,
Immediately after printing, one minute, two minutes, and five minutes later, high-quality paper is stuck to the printed surface, and it is observed whether or not the ink is transferred to the high-quality paper. Measure the time until it stops transferring at all,
The three-stage evaluation was performed as follows. ○: less than 1 minute Δ: 1 minute or more and less than 5 minutes. X: 5 minutes or more.

[Print Density] The print density of the solid black portion was measured using a Macbeth reflection densitometer (Macbeth, RD-920). The numbers shown in the table are the average values of five measurements. [Glossiness of print portion (shininess)] The glossiness of the print portion was visually observed from a lateral angle of 20 ° with respect to the print portion, and evaluated in three steps as follows. ：: There is the same level of shine as a silver halide color photograph. Δ: Inferior to color photograph, but high shine. X: The level of printed product of coated paper or lower.

[Printed part stickiness] The printed part was lightly pressed every 10 seconds immediately after printing on the black solid printed part, and the time when the fingerprint was not attached to the printed part was measured and evaluated. ：: less than 10 seconds Δ: 10 to 60 seconds ×: 60 seconds or more [Coating smoothness] The surface smoothness of the coating film was visually observed. ：: The surface of the coating film has almost no irregularities and is extremely smooth. Δ: A small amount of unevenness is observed on the surface. X: The surface is considerably uneven.

[0034]

[Table 1]

[0035]

As is clear from Table 1, the ink jet recording medium obtained by the present invention has good ink absorption speed and ink absorption capacity, and has high gloss and high print density after ink reception. It is.

Claims (4)

[Claims] 1. An ink jet recording medium comprising a support having at least one lower layer mainly composed of a resin having an affinity for water or a polyhydric alcohol and at least one porous upper layer having a porosity. After the upper layer is coated and formed on the molding surface, it is transferred to the lower layer, the molding surface is peeled off, and the porous upper layer has an average particle size of 10 to 300.
An ink jet recording medium comprising fine particles of nm. 2. The resin having an affinity for water or a polyhydric alcohol is at least one selected from partially saponified polyvinyl alcohol and polyvinylpyrrolidone.
The ink-jet recording medium according to the above. 3. The porous upper layer has an average particle size of 10 to 300 nm.
3. The ink-jet recording material according to claim 1, wherein the ink-jet recording material comprises secondary particles and a water-soluble resin. 4. A method for producing an ink jet recording medium comprising a support having at least one lower layer mainly composed of a resin having an affinity for water or a polyhydric alcohol and at least one upper layer of a porous material. After the upper layer having a property is coated on the molding surface, it is transferred to the lower layer, and the molding surface is peeled off.
A method for producing an ink jet recording medium, comprising fine particles of 0 to 300 nm.