JPH0231673B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses an inkjet recording method in which characters and images are formed by flying minute droplets of ink, and records images with excellent ink absorption ability, color reproducibility, weather resistance, gloss, etc. It relates to a recording medium that obtains.

In recent years, the inkjet recording method has been characterized by its high speed, high resolution, low noise, ease of multicolor printing, and great flexibility in recording patterns. It is rapidly becoming popular in many applications.

In particular, it is attracting attention as a means of obtaining color hard copies for computer terminals, etc., by taking advantage of the fact that various ink liquids can be used and the recording pattern is highly flexible. Furthermore, the images formed by the multicolor inkjet method are comparable to those produced by normal multicolor printing, and when the number of copies to be produced is small, it is cheaper than the normal plate making method. Attempts are being made to apply it to the field of color photographic printing.

In general, inkjet recording methods include a charge amount control method, a pressure vibration type such as an electric field control method, an electrostatic acceleration type in which ink is ejected electrostatically accelerated by a voltage between a counter electrode, and a pressure pulse method. There are on-demand pressure pulse type methods that push ink out, and ink mist methods that generate mist using ultrasonic vibrations, but in either case, a recorded image is obtained by attaching liquid ink droplets to a recording medium. It is.

High-quality paper and coated paper used for general printing, baryta paper and resin coated paper used as the base for photographic paper, and transparent polymer films used as light-transmissive recording media such as overhead projectors are ink. When used for inkjet recording, the ink remains on the surface for a long time and may come into contact with parts of the device, be touched by the operator, or continuously ejected sheets may overlap. If the recording surface is rubbed, the residual ink may stain or bleed the image, making it difficult to obtain a clear image.
Therefore, when using conventional water-based ink,
It has been practically impossible to make clear ink jet recordings on these recording media. If a highly volatile oil-based ink is used, the image dries quickly, so the above-mentioned disadvantages do not occur, but it is not preferable in terms of odor, toxicity, etc.

Therefore, when recording using the inkjet recording method, ink, especially water-based ink, has good absorbency, and ink droplets adhering to the recording medium are quickly absorbed into the ink receiving layer, resulting in an apparently dry state. Furthermore, the recording medium is required to ensure that the diameter of the absorbed ink dots does not become larger than necessary. Furthermore, as various color hard copies became available as printers and blotters for computer terminals, inkjet images could be obtained on transparent films that could also be used as recording media for optical projection types such as overhead projectors, and photographic prints became available. There has been a demand for inkjet recording media with good weather resistance and glossy surfaces, such as multicolor printing on paper or coated paper.

In general, an ink-absorbing ink-receiving layer must have a large number of voids to absorb and retain ink, and therefore, an ink-receiving layer with many voids naturally has many interfaces with air and has a microscopic surface. It has many irregularities, which diffusely reflects light and prevents it from passing through, making it less glossy and opaque. Furthermore, since it becomes difficult for light to reach the ink that has penetrated into the sky, the colors of the image become whitish and the color reproducibility and color density decrease.

The present invention was achieved as a result of various studies on methods for creating clear inkjet recorded images with improved weather resistance on recording media. A second layer is provided, and a solvent is applied thereon or the second layer is melted or melted by heating to form a film. An outermost layer consisting essentially of thermoplastic organic polymer fine particles is provided, and after using these layers as an ink-receiving layer, ink is jetted by an inkjet device to form a recorded image on the ink-receiving layer. By forming an organic polymer into a film, a recording medium with excellent water resistance and light resistance is provided.

The present invention will be explained in detail below. Supports used in the present invention include polyester, polysulfone, polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate,
Transparent films such as cellulose acetate, polyethylene, and polypropylene, or films filled with white pigments or whitened by fine foaming, synthetic papers, general paper, corded paper, baryta paper, resin-coated paper, and An opaque sheet material such as a metal box is used. Examples of white pigments filled in the paper layer or hum layer include titanium oxide, calcium sulfate, calcium carbonate, silica, clay, talc, and many other pigments that are normally used as fillers, pigments for paints, and kneading. things are available. There are no particular limitations on the thickness of these supports, but those of 10 μm to 300 μm are usually used. In addition, in order to improve the adhesion between the film and the ink receiving layer, corona discharge treatment,
It is also possible to carry out general treatments to improve adhesion, such as flame treatment, or to provide a subbing layer. In this case, a resin layer such as gelatin or nitrocellulose is usually used as the subbing layer.

The ink-receiving layer provided on the support mainly consists of a second layer in which a pigment with a large specific surface area that has a large ability to absorb and retain ink is coated together with an adhesive, and a second layer in which a fine-grained thermoplastic organic polymer is used as the main pigment. ,
It consists of an outermost layer that is coated with an appropriate amount of adhesive and dried.

Pigments with high absorption capacity used in the second layer include light calcium carbonate, aluminum hydroxide, synthetic alumina, zinc oxide, and synthetic silica. Pigments in the form of secondary aggregate particles of 50 μm are preferred.

The composition of the fine particulate thermoplastic organic polymer used for the outermost layer includes, for example, polymonobinylidene aromatics such as polystyrene, polymethylstyrene, polymethoxystyrene, and polychlorostyrene, polyvinyl chloride, polyvinyl-cyclohexane, polyethylene, Polyolefins and polyhaloolefins such as polypropylene and polyvinylidene chloride,
polymethacrylate, polychloroacrylate,
These include esters of α, β-ethylenically unsaturated acids such as polymethyl methacrylate, and copolymers thereof.

The particulate thermoplastic organic polymer used in the present invention is preferably a so-called slurry-like plastic pigment prepared by emulsion polymerization from one or more vinyl monomers, a dried product thereof, and a solid plastic pigment. It can be obtained as a fine powder or a powder formed into fine particles by pulverizing it by various means. The size of these thermoplastic organic polymer fine particles is usually 0.01 μm to 50 μm in diameter, preferably 0.05 μm to 30 μm, so that the voids necessary for absorbing ink in the ink receiving layer can be formed. .

In the present invention, these inorganic pigments and organic fine particles are used as the main pigment, and an adhesive in an amount of 2 parts to 30 parts, preferably 5 parts to 20 parts based on the pigment is mixed therewith and dispersed in water or a suitable solvent to form a paint. , and are sequentially coated on the support and dried to form an ink-receiving layer.

Adhesives used in the ink receiving layer include:
For example, starches such as oxidized starch, etherified starch, esterified starch, and dextrin, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, casein, gelatin, soybean protein, polyvinyl alcohol and its derivatives, maleic anhydride resin, and ordinary styrene. Conjugated diene polymer latex such as butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylic polymer latex such as polymer or copolymer of acrylic acid ester and methacrylic acid ester,
Thermosetting synthesis of vinyl polymer latices such as ethylene vinyl acetate copolymers, functional group-modified polymer latexes using monomers containing functional groups such as carboxyl groups, melamine resins, urea resins, etc. A resin adhesive or the like is used. It is also possible to use cationically modified starch, polyvinyl alcohol, and various nitrogen-containing cationic resins in combination.

Furthermore, if necessary, pigment dispersants, thickeners, flow modifiers, antifoaming agents, foam inhibitors, mold release agents, coloring agents, etc. may be appropriately blended without any problem.

As a coating machine, blade coaters, air knife coaters, roll coaters, plastic coaters, curtain coaters, chain coaters, per coaters, gravure coaters, etc., which are generally used in the production of pigment-coated paper, are applicable. I can do it.

After coating, the coating layer is dried by various conventional drying methods such as gas heater, electric heater, steam heating heater, hot air heating, etc. to form a coating layer. In this case, it is necessary that the temperature applied to the coating layer be below the melting point of the thermoplastic organic polymer fine particles used. If the coating layer is dried to a temperature higher than the melting point of the organic pigment, the organic pigment will fuse and form a film, which will reduce the ink absorbency, which is an important element of the ink-receiving layer.

Each coating layer may be provided in the required amount at one time,
It is also possible to obtain the necessary suitability by overcoating two or more times, but what is important for the present invention is to provide the two layers with high absorption capacity mainly composed of inorganic pigments, and then Adjacent to the surface layer, an outermost layer consisting mainly of an organic polymer pigment is provided.

The coating amount of the second layer varies depending on the specific surface area of the inorganic pigment, but is usually 10 g/m ² to 50 g/m ² and preferably 15 g/m ²
It is necessary to increase the absorption capacity by setting it to ~40g/ ^m2 . The coating amount of the organic polymer pigment in the outermost layer provided thereon is 5 g/m ² to 30 g/m ² , preferably 8 g/m ² to 25 g/m ² , but the organic pigment particles themselves do not absorb ink. The absorption capacity of this layer is between particles 〓
Since it is only a small size, it cannot be made too large.

In the present invention, the ink absorption capacity of the second layer or the outermost layer refers to the ink holding capacity per unit area of the multilayer, but it cannot be measured after the two-layer structure has been created. do not have. Therefore, when measuring the ink absorption capacity of each layer, the following method is used. The surface of the polyester film is made hydrophilic by corona discharge treatment, and each of the above layers is applied separately to the corona-treated surface to the actual coating amount, and if necessary, supercalender as in the actual manufacturing process. Use the hung piece as the test piece.

Accurately measure the size (area) of each test piece, immerse it in ethylene glycol solution at 20℃ for 30 seconds, pull it out, absorb the excess ethylene glycol on the surface with paper, immediately measure the weight, and measure the ethylene glycol solution. The absorption capacity per unit area is calculated using the specific gravity of glycol as the ink absorption capacity. These values are factors determined by the specific surface area of the pigment in the layer, the shape, and the coating amount of the coating layer. In the present invention, the absorption capacity of the second layer measured in this way is 1 ml/m2 ^or more, preferably 3 ml/m2 or more.
m ² or more, and it is desirable that the absorption capacity of the ink receiving layer including the outermost layer is 3 ml/m ² or more, preferably 4 ml/m ² to 60 ml/m ² .

Various methods have been developed for the method of applying ink into the ink-receiving layer in the present invention, that is, as inkjet recording devices, such as pressure vibration type, electrostatic acceleration type, and pressure pulse type. If it is possible to make the particles fly as minute droplets or mist and attach them to a predetermined position on the recording medium, that method is applicable.
There are no particular restrictions on the type of ink liquid. However, as the coloring dye in the ink liquid used, water-soluble direct dyes, acid dyes, basic dyes, etc. are generally suitable for use.

The role of the outermost layer is to immediately absorb ink that flies and adheres to the outermost layer and transfer part or all of it to the second layer, which has a high ink-sealing ability, and to form a film by appropriate means after inkjet recording. , to protect recorded images from water and light.

An ink-receiving layer consisting of a second layer of inorganic pigment and thermoplastic organic polymer fine particles is provided on the support, and when characters and images are recorded on the ink-receiving layer with an inkjet recording device, the ink-receiving layer is The image is whitish and opaque because it has a lot of sky.

In the present invention, the thermoplastic organic polymer in the outermost layer of the ink receiving layer having the inkjet recorded image is
A process of dissolving or melting it into a film to form a water-resistant transparent layer is required.

Methods for forming the outermost layer into a film include methods of applying a thermoplastic organic polymer solvent and dissolving it, or applying heat to melt and form a film.

It is advantageous to form a film by adding a substance that lowers the melting point of the thermoplastic organic polymer, especially a plasticizer, to the polymer before heating.

Methods for applying these solvents and plasticizers to the outermost layer of the ink-receiving layer include applying the solvents and plasticizers directly with a coating device, applying them by spraying, immersing them in a bath, and applying them as an emulsion. A method in which the solvent or plasticizer is mixed at the time of coating layer formation, a method in which the solvent or plasticizer is sprayed from a specially provided nozzle during or after inkjet recording, and attached to the ink-receiving layer, or a method in which microcapsules containing the solvent or plasticizer are applied to the ink-receiving layer in advance. A method in which the microcapsules are contained in a layer, and after inkjet recording, the microcapsules are destroyed by an appropriate means such as pressure to release the solvent and plasticizer contained therein, and another sheet coated with these microcapsules is coated. There is a method in which the microcapsules are destroyed by applying pressure with their surfaces facing each other and the contents are transferred to the ink-receiving layer. When a solvent is applied, the thermoplastic organic polymer fine particles in the outermost layer of the ink-receiving layer are dissolved and formed into a film. In addition, when heated above the melting point of the thermoplastic organic polymer, the outermost layer melts and forms a film.At this time, a substance that lowers the elastic modulus and glass transition point of the thermoplastic polymer or a substance that reduces the melt viscosity is added in advance. It is desirable to leave it in place or apply it from the outside and then heat treat it to make it easier to form a film. The substances used in this case are liquids with relatively low volatility, and plasticizers of thermoplastic polymers are particularly suitable.

Furthermore, it is not possible to contain ultraviolet absorbers, antioxidants, mold release agents, light stabilizers, etc., which are normally used in thermoplastic resins, in the ink-receiving layer, or to add them together with solvents and plasticizers. It is desirable to prevent deterioration of the thermoplastic polymer film and to improve the weather resistance of dyes in inkjet images.

When using the method of dissolving the thermoplastic organic polymer in a solvent to form a film in the present invention, the solvent is to dissolve the water-insoluble thermoplastic organic polymer fine particles being used, and to make at least the surface fluid. Refers to an organic solvent that has the effect of adhering to each other and reducing the interface. Typical examples include aliphatic hydrocarbons such as gasoline, benzine, and petroleum naphtha, aromatic hydrocarbons such as benzene, toluene, and xylene, trichlorethylene, perchlorethylene,
Halogenated hydrocarbons such as chloroform, carbon tetrachloride, ethylene trichloride, benzene monobromide, benzene dichloride, amyl alcohol, isopropyl alcohol, 2-ethylhexyl alcohol, cyclohexanol, methyl amyl alcohol, benzyl alcohol, butyl alcohol, etc. alcohols, acetone, acetonylacetone, diisobutyl ketone, diethyl ketone, methyl amyl ketone, methyl butyl ketone, methyl cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone, medicyl oxide,
Ketones, acetate esters, butyrate esters, propionate esters, formate esters, etc.
Butyl lactate, isopropyl lactate, ethyl lactate,
Alcohol ethers such as ethyl oxypropionate and diethyl maleate, ethyl acetoacetate,
Ketone esters such as ethyl pyrupate, ethers such as isopropyl ether, ethyl ether, diethyl carbitol, diethyl cellosolve, butyl ether, acetonyl methanol, diacetone alcohol, dihydroxylacetone,
Ketone alcohols such as birubil alcohol, ether alcohols such as isopropyl cellosolve, carbitol, glycidol, cellosolve, glycol ether, benzyl cellosolve, butyl carbitol, butyl cellosolve, methyl carpitol, methyl cellosolve, triethylene glycol monoethyl ether, Ketone ethers such as acetal ether, acetonyl methanol ethyl ether, methyl ethoxyethyl ether, butyl carbitol acetate, butyl cellosolve acetate, carbitol acetate, cellosolve acetate, 3-methoxybutyl acetate, methyl carpitol acetate, methyl cellosolve acetate There are ester ethers such as Alternatively, a mixture of these can be used as a solvent, and it is also effective to use a mixture when it is necessary to adjust the drying rate, etc.

In addition, when forming a thermoplastic organic polymer into a film by heating, when adding a substance that lowers the glass transition point or melt viscosity, it is necessary to add a relatively low-volatility liquid to the polymer to improve its elasticity. It is a substance that lowers the glass transition point and melt viscosity, making it easier to deform when heated, and is mainly used for organic acid esters, phosphoric esters, sulfonic acid esters, amides, and aliphatic esters. There are polyesters, epoxy plasticizers, chlorine-containing plasticizers, etc. Phthalate esters are particularly effective; typical examples include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), and di-n-octyl phthalate (DnOP). ), diisooctyl phthalate (DIOP),
Di-(2-ethylhexyl)-phthalate (DOP), dinonyl phthalate (DNP), diisodecyl phthalate (DIDP), ditridecyl phthalate (DTDP), diallyl phthalate (DAP),
Butylbenzyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-(2-ethylhexyl)-tetrahydrophthalate (DOTP)
etc. can be mentioned.

Furthermore, it is also possible to use liquid ultraviolet absorbers, light stabilizers, antioxidants, and the like.

In the present invention, when applying a solvent or a plasticizer, the microcapsules are generally prepared by the following method.

In other words, microcapsules encapsulating a solvent and/or plasticizer are microcapsules that are made of a polymeric substance that is insoluble in both water and the solvent and/or plasticizer.
Or they are microparticles of 1 μm to several tens of μm that contain a plasticizer. The wall materials used include those made of a combination of polycation and polyanion such as gelatin-gum arabic, and those made of a combination of condensation compositions such as polyisocyanate-polyamine, urea-formalin, and melamine-formalin.

Methods for producing such microcapsules include a coacervation method, an interfacial polymerization method, an in situ method, and the like.

The coacervation method is an encapsulation method that utilizes the phase separation phenomenon of colloids, and is a method that relies on electrical interaction between polycation colloids and polyanionic colloids (US Pat. No. 2,800,457, US Pat. No. 2,800,458, etc.). In the interfacial polymerization method, different types of monomers are contained in both the dispersion medium and the core material dispersed therein, and polymerization or condensation is performed at the interface between the two, that is, on the surface of the core material to form a polymer microcapsule wall film. It is a method of forming
No. 1046409, etc.). In the in situ method, monomers and polymerization catalysts for the membrane material are supplied only from the inside or outside of the core material, and conditions are set so that the reaction occurs on the surface of the core material, and polymerization or condensation is performed to produce a polymer. is used as the wall membrane of microcapsules (Special Publication No. 36-9168, No. 47
-23165, JP-A-48-57892, JP-A-51-9079, etc.). In addition, chemical methods such as in-liquid curing coating method (orifice method), in-liquid drying method, melting dispersion cooling method, etc.
Physicochemical and mechanophysical methods are known.

Methods for destroying microcapsules include applying pressure between surfaces or roll nips, heating to rupture and melt the capsule membrane, and irradiation with light to degrade the microcapsule membrane and release the contents. There are no particular restrictions on the heating method, such as pressing onto a heated metal plate or metal roll, using radiant heat from an electric heater or infrared lamp, or using hot air. At this time, it is also effective to apply a transparent plastic film or the like to the surface and heat and press it to form a smooth surface.

After inkjet recording on the ink-receiving layer formed in this manner, in which a second layer with a high absorption capacity is provided on the support and an outermost layer made of fine thermoplastic organic polymer particles is provided thereon, the outermost layer is A recording medium coated by either method has excellent clarity of recorded images, color reproducibility, and color density, and becomes a glossy inkjet recording medium with excellent water resistance and light resistance.

In the present invention, a transparent polymer film or a semi-transparent sheet is used as a support, which is excellent as a second original image because of its good light transmittance.

In addition, when coated paper coated with white pigment, opaque synthetic paper, baryta paper, resin coated paper, or other high-quality printing paper or photographic support is used as a support, the inkjet image will appear glossy on the opaque support. It is obtained as a film and is excellent as a recording medium that provides a highly glossy image with excellent color reproducibility, color density, and resolution.

Furthermore, if you use a support that has a silky, fine-grained surface, etc. known in the photographic industry, you can obtain a surface equivalent to that, and when forming the ink-receiving layer into a film, you can also use a patterned surface. If the ink jet is pressed against the ink jet, it is possible to obtain an inkjet recorded image with a corresponding patterned surface.

The present invention will be described below with reference to examples, but it is not limited to these examples. Note that parts and percentages shown in the examples mean parts by weight and percentages by weight.

Example 1 40 parts of wet-process synthetic silica (Nipseal NS manufactured by Nippon Silica Co., Ltd.) as an inorganic pigment and 5 parts of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA117) as an adhesive were added to a corona-treated 75 μm polyester film.
155 parts of water was prepared, applied to a solid content of 9 g/m ² and dried.
layered. The ink absorption capacity of this second layer is 7ml/
It was ^m2 . Additionally, 50 parts of polystyrene plastic pigment (LYTRON RX-1259 manufactured by Monsanto) was used as thermoplastic organic polymer fine particles, and polyvinyl alcohol (manufactured by Kuraray) was used as an adhesive.
A paint consisting of 5 parts of PVA105) and 95 parts of water was prepared, and the outermost layer was applied on the second layer to a solid content of 5 g/m ² and dried. The ink absorption capacity of the ink receiving layer including the second layer and the outermost layer is 10ml/
It was ^m2 . Characters were recorded on this as a recording medium using an inkjet device, and then m-xylene was sprayed and air-dried. The recording medium became a translucent recording medium that recorded characters with high resolution. When I made a diazo copy using this as a second original, I was able to make a copy with a clear background.

Example 2 (1) A microcapsule dispersion containing an organic solvent was prepared as follows.

80 parts of toluene was emulsified in 100 parts of a 5% aqueous solution with a pH of 4.0 in which a styrene maleic anhydride copolymer was dissolved together with a small amount of sodium hydroxide to give an average particle size of 8 to 9 μm.

10 parts melamine, 37% formaldehyde aqueous solution
25 parts and 65 parts of water were adjusted to PH9 with sodium hydroxide,
When heated to 60℃, it became transparent in 15 minutes and a melamine-formalin initial condensate was obtained.This initial condensate was added to the emulsion, the liquid temperature was brought to 60℃, and stirring was continued. Since the formation of capsules was confirmed, the mixture was cooled to room temperature. The average particle size of the obtained microcapsules is 9 to 10 μm.
The solid content concentration was approximately 45%.

(2) Prepare a paint consisting of 5 parts of polyvinyl alcohol (PVA117 manufactured by Kuraray Co., Ltd.) as an adhesive, 50 parts of light calcium carbonate (Univers 70 manufactured by Shiraishi Industries) as an inorganic pigment, and 95 parts of water, and have a thickness of 150 μm.
20g/m ² on one side of synthetic paper (Oji Yuka Yupo)
This was applied and dried to form the second layer.
The ink absorption capacity of this second layer was 11 ml/m ² .

(3) Separately, 50 parts of the microcapsule dispersion prepared in (1) above, 100 parts of methyl methacrylate emulsion polymer (concentration 48%) with an average particle size of 0.8 μm as thermoplastic organic polymer fine particles, and styrene as an adhesive.
Add 2 parts of butadiene copolymer latex and water to prepare a coating solution with a concentration of 40%, and apply it on the second layer created in (2) above at a solid coating weight of 10 g/m ² It was dried and used as a recording medium. The absorption capacity of the ink receiving layer of this recording medium was 18 ml/m ² .

(4) After recording an image on the recording medium created in this way using water-based ink using a color inkjet device, when a Niprol pressure of 50 kg/cm was applied, the microcapsules in the outermost layer were destroyed and the methyl By dissolving the methacrylate plastic pigment and creating a transparent film, the colors of color images become clearer and the recording medium does not wash away even when water is poured on it.

Example 3 (1) 10 parts of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA117) as an adhesive, 50 parts of synthetic silica (manufactured by Fuji Davison Co., Ltd., Cyroid 620) as an inorganic pigment
A coating solution was prepared consisting of 200 parts and 200 parts of water.

The above coating solution was applied to a solid content of 24 g/m ² on a photographic support which had a transparent polyethylene layer on the back side of the base paper and a titanium-containing polyethylene layer on the front side and was treated with corona, and dried. This was used as the second layer. The ink absorption capacity of this second layer was 19 ml/m ² .

(2) Prepare a coating solution consisting of 5 parts of polyvinyl alcohol (PVA117 manufactured by Kuraray Co., Ltd.) as an adhesive, 50 parts of L-8801 (polystyrene plastic pigment manufactured by Asahi Dow) as thermoplastic organic polymer fine particles, and 95 parts of water. On the second layer prepared in (1), it was applied to a solid content of 15 g/m ² and dried to obtain a recording medium.

(3) When an image was recorded on this recording medium using a color inkjet device, the ink was immediately absorbed, resulting in a whitish image.

When this image surface was sprayed with a solution of 1 part of ultraviolet absorber in 100 parts of ethyl acetate, the outermost plastic pigment became a dissolved film, resulting in clearer colors and excellent water resistance and light resistance. A recording medium with a recorded image was obtained.

Example 4 The same recording medium as in Example 3 was used until an image was recorded on the recording medium obtained up to (2) of Example 3 using a color inkjet device, and the image surface was coated with DOP.
(Di(2-ethylhexyl) phthalate) and 20 parts of liquid light stabilizer were added to the solution at 5 g/m ² and applied.
When hot air at 105°C was applied, the plastic pigment melted into a film and a shiny surface was obtained.

Images on this recording medium have excellent water resistance and light resistance.
A recording medium resembling a photograph was obtained because it had a glossy recording surface with vivid colors.

Example 5 (1) A microcapsule dispersion containing a plasticizer was prepared as follows.

Dissolve 200 parts of water, 10 parts of urea, and 1 part of resorcinol in 100 parts of 10% ethylene-maleic anhydride copolymer solution, and dissolve in 20% sodium hydroxide aqueous solution.
Adjusted to PH3.5. 200 parts of di(2-ethylhexyl) phthalate (DOP) was added to this and emulsified and dispersed to give a thickness of 15 μm. Then, after adding 26 parts of 37% formaldehyde aqueous solution, the temperature of the system was increased to 55℃.
After reacting for 3 hours, the mixture was cooled to obtain a microcapsule dispersion containing a plasticizer.

The average particle size of the obtained microcapsules is 15μ
m, and the solid content concentration was approximately 40%.

(2) Microcapsule dispersion prepared in (1) above
Prepare a coating solution by thoroughly mixing 100 parts and 40 parts of a 10% polyvinyl alcohol solution, and apply it to a corona-treated transparent polyester film with a thickness of 50 μm so that the solid content is 10 g/m ² .
The dried material was used as an upper leaf sheet.

(3) The same recording medium as in Example 3 was used until an image was recorded on the recording medium obtained up to (2) of Example 3 using a color inkjet device, and this recorded image surface and the image created in (2) above were used. The coated surfaces of the prepared upper sheets were stacked one on top of the other, facing each other, and a pressure of 60 kg/cm ² was applied to bring them into close contact. The microcapsules on the upper sheet were destroyed and the contents were transferred to the ink-receiving layer, so when the upper sheet was peeled off and pressed against a rough roll with a surface temperature of 110°C, the plastic pigment melted and it was the same as the rough roll. It became a film with a matte surface.

It became a photograph-like recording medium with excellent color density and color reproducibility, and a matte surface with good water resistance and light resistance.

Claims (1)

[Scope of Claims] 1. In an inkjet recording medium provided with an ink-receiving layer consisting of two or more different pigment layers on a support, the outermost layer of the ink-receiving layer is substantially made of a thermoplastic organic material. 1. A recording medium for inkjet, comprising fine polymer particles, and a second layer adjacent to the outermost layer comprising an inorganic pigment layer having a large ink absorption capacity. 2. The inkjet recording medium according to claim 1, wherein the ink-receiving layer has an ink absorption capacity of 4 ml/m ² or more.