JPH11245506A - Base material, recording medium employing the base material, and recording method employing the recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the characteristics of texture, image density, saturation, and glossiness by providing a layer containing a while pigment having an anti- elusion property relative to water on a fibrous structure base body. SOLUTION: A white pigment-containing layer formed on the surface of a fibrous structure base body can be obtained by dispersing a white pigment in water or a solvent to subsequently be mixed with a binder to be coating paint, and then this is coated and dried on the surface of a fibrous base body. Giving water to the white pigment-containing layer prevent a constitutional component of the layer, mainly, a white pigment from being eluded in water and also dispersing in water through the combination disconnection of the white pigment among its grains. To this, an anti-elusion property to water is given on the surface of the white pigment-containing layer. As such, a constitutional component of the layer containing a white pigment can be restrained from being blended into water coating liquid for formation of a porous layer containing an alumina water dispersible matter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a base material suitable for forming a recording medium capable of obtaining a clear and glossy image, a recording medium using the base material, and a recording method using the recording medium.

[0002]

2. Description of the Related Art In an ink-jet recording system, fine droplets of a recording liquid (recording liquid) such as ink are caused to fly according to various operating principles and adhere to a recording medium such as paper to form an image,
It records characters, etc., and has features such as high-speed, low noise, easy multi-coloring, great flexibility in recording patterns, and no need for development.
It has been spread to information devices such as copiers, word processors, fax machines, plotters, etc., and is rapidly spreading. In recent years, high-performance digital cameras, digital videos, and scanners have been provided at low cost, and in conjunction with the widespread use of personal computers, opportunities for outputting image information obtained therefrom by an inkjet recording method have been increasing. For this reason, there is a demand for an image output by an ink jet method which is comparable to silver halide photographs and multicolor printing of a plate making method.

[0003] For this purpose, recording apparatuses and recording methods have been improved, such as high-speed recording, high-definition recording, and full-color recording. However, advanced characteristics have also been required for recording media. .

Under such circumstances, the characteristics generally required of a recording medium include (1) a high ink absorption speed and no bleeding more than necessary, and (2) a high print density and high color development. And (3) excellent weather resistance.

[0005] In response to such demands, various kinds of recording media have been conventionally proposed. For example, JP-A-52-90
No. 74 discloses a recording medium in which a layer having voids containing a silica-based pigment having a large specific surface area as a main component is provided as an ink receiving layer in order to improve the ink absorption speed,
JP-A-63-22997 discloses a recording medium in which the amount of voids in a pigment layer forming an ink receiving layer is adjusted. JP-A-55-51583 and JP-A-56-157 disclose an amorphous silica powder in order to increase the ink absorption by an ink receiving layer and obtain print dots having high print density and no ink bleeding. Is disclosed.

Japanese Patent Application Laid-Open No. 55-144172 discloses that a specific substance which adsorbs a dye component is disclosed in Japanese Patent Application Laid-Open No. 55-144172, focusing on the fact that the coloring property and the sharpness depend on the distribution state of the dye in the ink in the ink receiving layer. Is disclosed. Japanese Patent Application Laid-Open No. 3-114873 discloses that ink absorption, water resistance and light resistance have been improved by using an ink jet recording medium provided with a coating layer containing barium sulfate and gelatin on a paper layer. ing.

Further, US Pat. No. 4,879,166.
No. 5,104,730, JP-A-2-276670, JP-A-4-37576, and JP-A-5-32037 disclose a recording medium in which a layer containing alumina hydrate having a pseudo-boehmite structure is used as an ink receiving layer. It has been disclosed. The recording medium using these alumina hydrates has a good fixation of the ink dye because the alumina hydrate has a positive charge, a high coloring property, and a high gloss image can be obtained. It has advantages over recording media.

Japanese Patent Application Laid-Open No. 7-89216 discloses that
An ink jet recording material comprising a layer containing a water-absorbing pigment on the substrate and an outermost layer containing pseudo-boehmite is disclosed, and the insufficient amount of ink absorption when only pseudo-boehmite is used is supplemented by the water absorbing pigment in the lower layer. Is disclosed.

[0009]

However, the formation of a recording medium using such an ink-absorbing pigment requires a high ink absorption in order to increase the ink absorption so that a high-definition image can be recorded in a short time. A method of coating a layer containing a pigment by a casting method on a fibrous base material having low absorbency and smoothness has been mainly used, but a recording medium obtained by such a method is a silver salt-based one. In many cases, the texture, image density, color saturation, and glossiness of a photograph are not sufficient to obtain the texture. In addition, lining is necessary to give texture, etc.,
In many cases, it is necessary to increase the coating thickness of the pseudo-boehmite layer in order to obtain image density and saturation, and at present, it is unavoidable to use a costly method for both materials and processes.

An object of the present invention is to improve characteristics such as texture, image density, saturation, and gloss of a recording medium using a substrate having a fibrous substance as a base. Another object of the present invention is to provide a base material which is excellent in these characteristics and can be efficiently manufactured, a recording medium using the base material, and a recording method using the recording medium.

[0011]

The base material for forming a recording medium of the present invention is a base material for forming a recording medium having a structure in which a layer containing a white pigment is provided on a fibrous base material. Is characterized by having a resistance to elution with water. A porous layer containing alumina hydrate is provided on the layer containing the white pigment of the base material, and an ink receiving layer is formed from at least the layer containing the white pigment and the porous layer containing alumina hydrate. The recording medium can be obtained by forming. In addition, a porous thermoplastic resin layer can be provided on the surface of the ink receiving layer as needed.

According to the present invention, the interface structure between the layer containing the white pigment forming the ink receiving layer and the porous layer containing the alumina hydrate is improved so that the texture, image density, saturation and glossiness are improved. Thus, it is possible to obtain a recording medium improved in respect of the above.

The resistance to elution of water in the layer containing a white pigment in the present invention means that when the layer comes into contact with water, the elution or dispersion of its constituents (mainly the white pigment component) in water is suppressed. I mean. The elution or dispersion of the components from the layer containing the white pigment into water need not be completely suppressed, provided that the elution or dispersion is suppressed to the extent that the effects of the present invention can be obtained. Good.

The resistance to elution is as follows: a substrate having a layer containing a white pigment is used as a test piece having a surface area of 18 cm ² , which is immersed in 700 times the volume of water of the layer containing the white pigment in the test piece; It can be evaluated by measuring the light transmittance of the aqueous phase after the ultrasonic treatment. In the present invention, the light transmittance of the aqueous phase is 10% or more at 200 nm,
It is preferable to use a substrate having a layer containing a white pigment showing 90% or more at 00 nm.

A recording image can be obtained by applying a recording liquid such as ink to the recording medium having the above-described structure in accordance with recording information, for example, by an ink jet recording method. When a porous thermoplastic resin layer is provided on the ink receiving layer, the porous thermoplastic resin layer is heated and melted to form a transparent film. Protective layer can be provided.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The substrate of the present invention has a structure in which a layer containing a white pigment is provided on the surface of a fibrous substrate. As the fibrous substrate, a substrate mainly composed of wood pulp and a filler can be used.
It is preferably 20 g / m ² or more, more preferably 150 g / m ² or more, and the upper limit thereof is preferably 180 g / m ² . By using a fibrous substrate having such a basis weight, a high-quality recording medium can be provided even in the size of, for example, A4 size or A3 size.

When the recording medium is constituted, a recording liquid such as ink (recording liquid: collectively referred to as ink hereinafter) comprises a porous layer containing alumina hydrate constituting an ink receiving layer; Since it is almost absorbed by the layer containing the white pigment located therebelow, the water absorption of the fibrous substrate itself is not so required, and conversely, it is necessary to improve the water resistance of the back surface and the cross section. The Stekigt sizing degree is preferably 1
It is desirable to use one having a duration of at least 00 seconds, more preferably at least 200 seconds.

In the present invention, the layer containing a white pigment formed on the surface of the fibrous substrate can be formed mainly of, for example, a white pigment and a binder. Examples of white pigments include inorganic white pigments such as silica, kaolin, clay, barium sulfate, calcium carbonate, and aluminum oxide, and these can be used alone or in combination of two or more. It is preferable to use a white pigment from which impurities are removed as much as possible in order to improve whiteness and light resistance. Further, those having an effective average particle diameter for improving the smoothness, whiteness, glossiness and solvent absorbability of the layer surface are desirable.

As the binder for binding the white pigment, any polymer having a binding ability can be used without any particular limitation as long as the effect of the present invention is not impaired. Examples of such a binder include synthesis of polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, casein, gelatin, soy protein, styrene-butadiene-based latex, polyvinyl acetate, polyacrylate, polyester, polyurethane, and the like. Polymers. These binders can be used alone or in combination of two or more.

The layer containing the white pigment can be obtained by dispersing the white pigment in water or a solvent, mixing the resultant with a binder, applying the coating on the surface of the fibrous substrate, and drying. . In this layer, if necessary, a dispersant, a thickener, a pH adjuster, a lubricant, a fluidity modifier, a surfactant,
It is also possible to add one or more of an antifoaming agent, a waterproofing agent, a release agent, a fluorescent whitening agent, an ultraviolet absorber, an antioxidant and the like.

The mixing ratio of the white pigment and the binder is preferably from 10: 0.7 to 10:10 by weight, with the upper limit being 10: 5 and the lower limit being more preferably 10: 1.

What is important here is that, by adding water to the layer containing the white pigment, the constituents of the layer, mainly the white pigment, are eluted into the water on the surface of the layer and the bond between the particles of the white pigment is reduced. It does not come off and disperse in water. That is, at the time of forming the recording medium, a porous layer containing alumina hydrate is provided on the layer containing the white pigment by using an aqueous coating solution. If the constituent components are eluted or dispersed in the aqueous coating liquid, the smoothness at these interfaces is reduced and the smoothness of the finally obtained recording medium surface is impaired, and the image is recorded. The feeling of homogeneity when performing is not obtained. In addition, the porous layer containing alumina hydrate is provided as a transparent layer, and when the aqueous coating liquid becomes cloudy due to the components released from the white pigment layer, the desired glossiness and color development can be obtained. Disappears. Furthermore, the incorporation of the components of the layer containing the white pigment into the aqueous coating liquid affects the drying characteristics in the process of forming the porous layer containing alumina hydrate,
Deterioration of the surface properties of the obtained porous layer containing alumina hydrate and defects such as cracks are liable to occur, and the thickness of the porous layer containing alumina hydrate is increased to improve ink absorption. It becomes an obstacle when doing.

On the other hand, by imparting the elution resistance to water to the surface of the layer containing the white pigment, the aqueous coating solution for forming the porous layer containing the above-mentioned alumina hydrate can be used. It is possible to suppress the incorporation of the components of the layer containing the white pigment, and as a result, it has good smoothness and surface properties, is excellent in properties such as gloss and coloring, and is a porous layer containing alumina hydrate. It is possible to obtain a recording medium free from defects such as cracks even when the recording medium is formed thick.

As the treatment for imparting the elution resistance, various processes can be used depending on the constitution of the layer containing the white pigment. Examples of the treatment for obtaining the elution resistance include a heat treatment, a combined use of a thermosetting resin and an acetalization treatment, and a chemical reaction with a hardener. For example,
When polyvinyl alcohol is used for the binder, the degree of saponification and the degree of polymerization are preferably as high as possible (for example, a saponification degree of 98% or more,
(Degree of polymerization of 1500 or more)
It is effective to perform a heat treatment for about 10 minutes.

The coating amount of the layer containing the white pigment on the substrate is determined so as to sufficiently absorb the solvent component of the ink.
In addition, 10 to 40 g / m is required to provide necessary smoothness.
A range of ² is preferred. The coating / drying method for forming the layer containing the white pigment itself is not particularly limited, but it is preferable to perform a surface smoothing treatment such as a super calender as a finishing step.

By providing a porous layer containing at least alumina hydrate on the substrate having the above structure, an ink receiving layer having a layer containing a white pigment and a porous layer containing alumina hydrate can be used as a fiber. It is possible to obtain a recording medium having a configuration provided on the substrate.

As the alumina hydrate used for forming the ink receiving layer, commercially available one or one produced by a known method using hydrolysis of aluminum alkoxide or sodium aluminate can be used. it can. The particle shape is not limited to a cilia shape, a needle shape, a plate shape, a spindle shape, and the like, and the presence or absence of orientation is not important. Further, alumina hydrate is more preferable as long as it has high transparency, glossiness and dye fixability, and does not crack when forming a film and has good coatability. Examples of commercially available products include “Cataloid AS-2” and “Cataloid AS-
3 "and" Alumina Sol-520 "manufactured by Nissan Chemical Industries, Ltd., and the like.

In order to prepare the non-oriented alumina hydrate, for example, a hydrolysis and peptization method of aluminum alkoxide and a hydrolysis and peptization method using aluminum nitrate and sodium aluminate can be used.

These alumina hydrates are usually fine particles having a particle size of 1 μm or less and have excellent dispersibility, so that the recording medium should have very good smoothness and gloss. Can be.

The binder used for binding the alumina hydrate can be freely selected from water-soluble polymers. For example, polyvinyl alcohol or a modified product thereof, starch or a modified product thereof, gelatin or a modified product thereof, casein or a modified product thereof, gum arabic, carboxymethylcellulose, hydroxyethylcellulose, cellulose derivatives such as hydroxypropylmethylcellulose, SBR latex, NBR latex, Conjugated diene-based copolymer latex such as methyl methacrylate-butadiene copolymer, functional group-modified polymer latex, vinyl-based copolymer latex such as ethylene-vinyl acetate copolymer, polyvinylpyrrolidone, maleic anhydride or a copolymer thereof And acrylate copolymers are preferred. These binders can be used alone or in combination of two or more.

The mixing ratio of the alumina hydrate and the binder is as follows:
The weight ratio is preferably 1: 1 to 30: 1, and the lower limit is 5: 1, and the upper limit is more preferably 25: 1. By setting the amount of the binder in these ranges, the mechanical strength of the ink receiving layer can be made favorable, and it becomes possible to prevent the occurrence of cracks and powder dropping and maintain a suitable pore volume.

The coating liquid for forming the layer containing alumina hydrate includes, in addition to the alumina hydrate and the binder, a dispersant, a thickener, a pH adjuster, a lubricant, a fluid Modifiers, surfactants, defoamers, water-proofing agents, mold release agents, optical brighteners, ultraviolet absorbers, antioxidants, etc. can be added as long as the effects of the present invention are not impaired. is there.
The coating amount of the layer containing the alumina hydrate, also preferably 30 g / m ² or less on a dry solid basis in order to have and necessary smoothness remembering dye fixability, 20 to 30 g / m ²
Is more preferable. The method of coating and drying is not particularly limited, but if necessary, a baking treatment can be performed after forming a layer containing alumina hydrate and a binder. By performing such a baking treatment, the crosslinking strength of the binder is increased, and the mechanical strength of the ink receiving layer is improved,
Further, the surface gloss of the alumina hydrate layer is improved.

In a more preferred embodiment of the present invention, a porous thermoplastic resin layer can be further provided as the outermost layer on the ink receiving layer in order to further improve the ink absorption rate and weather resistance. This layer has a function of allowing ink to pass through to an ink receiving layer provided therebelow by having ink permeability at the time of ink application in a recording operation, and to form a smooth continuous film by heating after completion of recording. It is possible to use, for example, a structure in which thermoplastic resin particles are used to bond each other so as to maintain appropriate porosity and maintain a layer form by using thermoplastic resin particles. it can.

As the thermoplastic resin particles, those made of various thermoplastic resin materials can be used. Examples of thermoplastic resin particles include, for example, vinyl chloride, vinylidene chloride, styrene, acrylic, urethane, polyester, ethylene, vinyl chloride-vinyl acetate,
Vinyl chloride-vinyl acetate system, vinyl chloride-vinyl acetate-
Latex particles as thermoplastic resin particles contained in acrylic acid-based, SBR-based, and NBR-based latexes can be suitably used, and the solid content of the latex can be adjusted if necessary. These particles are
They may be used alone or in combination of two or more as long as the film formability is not impaired.

The particle size of the thermoplastic resin particles is, for example, 0.1 μm to 10 μm, preferably 0.1 μm to 2 μm.
Can be mentioned.

In preparing a coating liquid containing thermoplastic resin particles, these materials are mainly dispersed in an appropriate solvent, for example, an aqueous solvent, and the solid content thereof is preferably in the range of 10 to 50% by weight. Although it is preferable, it can be appropriately adjusted according to the coating method. The coating amount is usually 2% in dry layer thickness in order to impart a surface gloss, suppress the appearance of interference colors, and obtain a thickness having a sufficient function as a protective film.
It is preferable to adjust the thickness to 10 μm.

An image can be formed by applying ink droplets to the ink receiving layer according to the recording information on the recording medium having the above configuration. In the case where a porous thermoplastic resin layer is provided on the outermost layer, a recorded image can be obtained by applying ink droplets and then making the porous thermoplastic resin layer on the surface nonporous (clear). Can be. When the porous thermoplastic resin layer is made nonporous, weather resistance such as water resistance and light resistance of an image can be improved, gloss can be imparted to an image, and printed matter can be stored for a long period of time.

As a method for making the outermost porous thermoplastic resin layer nonporous, there is a method of heating and melting the porous thermoplastic resin layer. The heating temperature has a relationship with time in consideration of the influence on the materials such as the base material, the ink receiving layer and the ink, and the surface properties after nonporous formation.
The range of -180 ° C is preferred.

The outermost layer may also contain a dispersant, if necessary.
Thickeners, pH adjusters, lubricants, flow modifiers, surfactants, defoamers, water-proofing agents, mold release agents, fluorescent brighteners, ultraviolet absorbers, antioxidants, etc. of the present invention You may add in the range which does not impair an effect.

The back surface of the fibrous substrate used in the present invention may be coated with various coatings as necessary to have functions such as curling prevention, improvement of water resistance and improvement of mechanical strength of the substrate. It is possible. Examples of the backside coating agent used for this purpose include gelatin, polyvinyl alcohol, various latexes, emulsions and the like, and these can be used alone or as a mixture of two or more. In order to prepare coating liquids for these back coating agents, it is preferable to disperse these materials in an aqueous solution and adjust the solid content thereof to a range of 2 to 10% by weight. It can be adjusted appropriately. The coating amount of the backside coating agent is desirably appropriately adjusted depending on the shrinkage ratio of the ink receiving layer and the porous thermoplastic resin layer on the front surface, but the coating amount is usually about 1 to 10 μm. Is preferred.

As a method for applying ink to a recording medium, an ink jet method is preferable. Among them, a method in which thermal energy is applied to ink to form ink droplets is used in terms of enabling high-speed printing and high-definition printing. It is preferable to employ a certain bubble jet method. The ink is preferably an aqueous ink, and the dye may be a dye or a pigment.

[0042]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Various physical properties relating to the present invention were measured by the following methods. 1) Elution resistance: Elution resistance was measured by the following procedure. (1) A piece of paper having a surface area of 18 cm ² is used as a sample and placed in a beaker. (2) Determine the coating volume of the white pigment layer and dilute it 700 times with water. (3) Immerse the beaker in a 37 KHz, 125 W ultrasonic bath at 25 ° C. for 5 minutes. (4) Take out the aqueous phase and measure its transmittance of the spectrophotometer solution. 2) Surface gloss: measured using a digital variable-angle gloss meter (manufactured by Suga Test Instruments Co., Ltd.). 3) Recording characteristics: At a nozzle interval of 16 nozzles per 1 mm,
An inkjet head having 128 nozzles is used for inkjet printing using an inkjet printer having four colors of yellow (Y), magenta (M), cyan (C), and black (Bk). OD
(Image density), ink absorbency, bleeding, and beading were evaluated. a) Ink Absorbency The ink absorbency on the surface of the recording medium after solid printing in single color or multicolor using the inkjet printer was examined by touching the recording portion with a finger. 100% ink volume for single color printing
When the ink was not attached to the finger at 300%, it was evaluated as ○, when the ink amount was 200%, the ink did not adhere to the finger, and when the ink amount was 100%, it was evaluated as x. b) Image density In the same manner as above, the image density of an image solid printed with Y, M, C, and Bk inks was measured using a Macbeth reflection densitometer RD-9.
18 was used for evaluation. c) Bleeding, beading Y, M, C, B using the above inkjet printer
The ink bleeding on the surface of the recording medium after the solid printing of each of the inks was performed in a single color or in multiple colors was evaluated. Also, Y,
Beading after solid printing of each of M, C, and Bk inks in a single color or in multiple colors was visually evaluated. When the ink amount in monochromatic printing is 100%, the ink amount is 300%
When the ink was not generated at the ink amount of 200%, it was evaluated as ○, and when it was generated at the ink amount of 100%, it was evaluated as ×. The beading referred to here is a phenomenon in which the applied ink dots come into contact with the next ink dots before they are absorbed and fixed on the recording medium, causing the print dots to be connected in a bead shape, resulting in uneven image density. It is.

The composition of the ink used for evaluation of the recording characteristics is as follows. (Ink composition 1) Dye 5 parts Ethylene glycol 10 parts Polyethylene glycol 10 parts Water 75 parts (Dye used) Y: C.I. I. Direct Yellow 86 M: C.I. I. Acid Red 35 C: C.I. I. Direct Blue 199 Bk: C.I. I. Food black 24 4) Surface defects: Surface defects (cracks, cissing, etc.) after coating are visually observed.

Example 1 100 parts by weight of barium sulfate having an average particle size of 0.6 μm formed by reacting sodium sulfate and barium chloride, 10 parts by weight of an aqueous gelatin solution, 3 parts by weight of polyethylene glycol, 0.2 parts by weight of chromium alum, TAF (Tri Aclylic Fo
rmaldehyde) was added to obtain a coating liquid. This coating solution is applied on a base paper for coating having a basis weight of 150 g / m ^{2 by} a die coater so as to have a dry thickness of 20 μm, and then subjected to a super calender treatment to obtain a substrate having a layer containing a white pigment. Was. The substrate was allowed to stand for one month in an environment of 50 ° C./80% RH to accelerate hardening of gelatin.
Table 1 and FIG. 1 show the results of the measurement of the elution resistance of this base material by the method described above.

Example 2 Pseudo-boehmite which is an alumina hydrate (catalyst A
After dispersing 10 parts by weight of S-2) and 1 part by weight of polyvinyl alcohol (PVA117 manufactured by Kuraray Co., Ltd.) in ion-exchanged water so as to have a solid content of 15% by weight, boric acid was used as a crosslinking agent for polyvinyl alcohol. One part by weight was added to obtain a coating liquid. This coating solution was applied on the layer having the white pigment of the substrate obtained in Example 1 using a bar coater so that the coating amount after drying was 20 g / m ² ,
And dried in an oven at 10 ° C for 10 minutes.
A baking treatment was performed at 2 ° C. for 2 minutes to form a porous layer of alumina hydrate, thereby obtaining a recording medium. This recording medium was evaluated for glossiness, printing characteristics, and surface defects.
Table 2 shows the results.

Example 3 After the supercalender treatment in Example 1, the layer containing the white pigment was again subjected to a baking process at 150 ° C. for about 1 minute 30 seconds by a coater to accelerate the curing of the coating film. Table 1 and FIG. 1 show the results of the measurement of the elution resistance of this base material by the method described above.

Example 4 The same porous layer of alumina hydrate as in Example 2 was formed on the base material-containing layer of Example 3 using a bar coater using a bar coater to obtain a recording medium. Table 2 shows the results of evaluating the glossiness, printing characteristics, and surface defects of this recording medium.
Shown in

Example 5 After the supercalender treatment in Example 1, the layer containing the white pigment was again overcoated with a formaldehyde compound solvent by a coater to accelerate the curing of the coating film. Table 1 and FIG. 1 show the results of the measurement of the elution resistance of this base material by the method described above.

Example 6 The same porous layer of alumina hydrate as in Example 2 was formed on the recording medium of Example 5 using a bar coater to obtain a recording medium. Table 2 shows the results of evaluating the glossiness, printing characteristics, and surface defects of this recording medium.

Comparative Example 1 100 parts by weight of barium sulfate having an average particle diameter of 0.6 μm formed by reacting sodium sulfate and barium chloride, 10 parts by weight of gelatin, 3 parts by weight of polyethylene glycol, and 0.2 parts by weight of chromium alum were blended. To obtain a coating solution. This coating solution was applied on a base paper for coating having a basis weight of 150 g / m ^{2 by} a die coater so as to have a dry thickness of 20 μm, and then subjected to a super calender treatment to obtain a substrate. Table 1 and FIG. 1 show the results of measuring the elution resistance of this recording medium without applying a curing treatment.

Comparative Example 2 The same porous layer of alumina hydrate as in Example 2 was formed on the recording medium of Comparative Example 1 using a bar coater to obtain a recording medium. Table 2 shows the results of evaluating the glossiness, printing characteristics, and surface defects of this recording medium. Comparative Example 3 After the supercalender treatment in Example 1, a baking step was performed again at 100 ° C. for 1 minute and 30 seconds with a coater to accelerate the curing of the coating film. Table 1 shows the results of measurement of the elution resistance of this base material by the method described above. Comparative Example 4 The same porous layer of alumina hydrate as in Example 2 was formed on the recording medium of Comparative Example 3 using a bar coater to obtain a recording medium. Table 2 shows the results of evaluating the glossiness, printing characteristics, and surface defects of this recording medium.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

According to the present invention, there is provided a recording medium capable of forming a recorded image having excellent properties such as ink absorbency, weather resistance, glossiness, dye fixing property and the like, which is inferior to a textured silver salt type photograph. It can be provided at low cost. Furthermore, in a system in which a porous thermoplastic resin layer is provided on the ink receiving layer, after printing,
By adding a treatment such as heating, properties such as glossiness and chroma, and weather resistance can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in transmittance with respect to a measurement wavelength obtained during measurement of elution resistance.

Claims (12)

[Claims] 1. A substrate for forming a recording medium having a structure in which a layer containing a white pigment is provided on the surface of a fibrous substrate, wherein the layer containing the white pigment has elution resistance to water. Substrate for forming a recording medium. 2. The elution resistance of the layer containing the white pigment is determined by immersing the base material in a test piece having a surface area of 18 cm ² in 700 times the volume of water of the layer containing the white pigment in the test piece. When the light transmittance of the aqueous phase after the ultrasonic treatment was measured, it was 10% or more at 200 nm and 90% at 300 nm.
%. 3. The coating amount of the layer containing the white pigment is 20
The substrate according to claim 1, wherein the substrate is in a range of ４０40 g / m ² . 4. The white pigment-containing layer is formed mainly of a white pigment and a binder.
5. The substrate according to any one of items 1 to 4, 5. The substrate according to claim 4, wherein the white pigment is barium sulfate. 6. The method according to claim 1, wherein a coating layer containing a white pigment is provided on the fibrous substrate, and then a treatment for imparting elution resistance to the surface of the coating layer is performed. The substrate according to any one of claims 1 to 5. 7. The substrate according to claim 6, wherein the treatment for imparting the elution resistance is a treatment by a chemical reaction or a heat treatment. 8. A substrate comprising the substrate according to claim 1, and a porous layer containing alumina hydrate provided on the layer containing the white pigment of the substrate. A recording medium, wherein the ink receiving layer comprises a layer containing a white pigment and a layer containing alumina hydrate. 9. The recording medium according to claim 8, further comprising a porous thermoplastic resin layer on the ink receiving layer. 10. A recording method, wherein a recording liquid is applied to an ink receiving layer of the recording medium according to claim 8 in accordance with recording information to perform recording. 11. Recording is performed by applying a recording liquid to the ink receiving layer of the recording medium according to claim 9 in accordance with recording information via the porous thermoplastic resin layer of the recording medium. A recording method comprising heating a porous thermoplastic resin layer to form a transparent film. 12. The recording method according to claim 10, wherein the application of the recording liquid to the recording medium is performed by an ink jet recording method.