JP2000108499A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium, which has a quick ink absorbing speed at recording, a large absorbing capacity, can print an image excellent in water resistance in high resolution and high density at a high speed without developing feathering in the image. SOLUTION: This ink jet recording medium contains dye fixative particles and polysaccharide polymer gels crosslinked with polyvalent metal ions. As the preferable dye fixative particle, a fine inorganic particle or a cationic polymer particle having a quaternary ammonium salt structure is exemplified. As the preferable polysaccharide polymer, a sodium alginate is exemplified. As the preferable polyvalent metal ion, a calcium ion, a barium ion or an aluminum ion is exemplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing a high-resolution, high-density, water-resistant image having a high ink absorption speed, a large absorption capacity, no bleeding, and a high resolution. It relates to a possible ink jet recording medium.

[0002]

2. Description of the Related Art In an ink jet recording system, dots are formed by ejecting minute ink droplets and attaching them to a recording medium such as paper, thereby recording images and characters. Since it has low noise, does not require processes such as development and fixing, and can easily perform full-color recording, it has rapidly spread to various fields such as various printers, facsimile machines, and computer terminals. In recent years, with the improvement of the performance of ink jet recording apparatuses such as high-speed and high-definition apparatuses and high-quality full-color apparatuses and the expansion of applications, more advanced characteristics have also been required for recording media. .

[0003] When the ink absorbing speed of the recording medium is low, not only smearing and bleeding due to the ink offset phenomenon occurs, but also when ink droplets of two or more colors are overlapped and recorded, the droplets are printed on the recording medium. However, a repelling phenomenon is caused to cause unevenness, and colors are mixed with each other in a boundary region of different colors, so that the image quality is apt to be greatly reduced. Therefore, it is required that the recording medium have high ink absorbency.

[0004] On the other hand, even if the ink absorbency is simply increased, the ink adhering to the recording medium penetrates deep into the recording medium, the effective amount of colorant in the ink near the surface layer decreases, and the printing contrast decreases. The problem arises. Further, when the attached ink spreads in the horizontal direction near the surface layer of the recording medium, it causes blurring of the print and lowers the resolution. further,
If the recording medium is thin or the ink penetrates deep into the recording medium, the print will come out on the back side of the recording medium,
The so-called strike-through easily occurs, and the quality of a printed image is significantly impaired particularly in the case of double-sided printing.

Therefore, as a recording medium used in the ink jet recording system, the density of print dots is high,
The color tone is bright and vivid, the ink absorbs quickly and the ink does not flow or bleed even when the print dots overlap, and the print dots do not spread more than necessary in the horizontal direction and Is required to have characteristics such as smoothness and blurring, and good image storability such as water resistance and light resistance of the recorded image.

To solve these problems, a recording medium is provided with an ink receiving layer containing a filler having an ink absorbing ability and a binder to quickly absorb liquid components in the ink to speed up drying and suppress bleeding. There are attempts to improve quality. For example, Japanese Patent Application Laid-Open No. 61-141584 discloses an ink containing a filler made of amorphous silica or the like having specific physical properties and a binder made of an aqueous polymer such as PVA, starch, or a water-soluble cellulose derivative. A receiving layer is disclosed. Japanese Patent Application Laid-Open No. 1-108083 discloses an ink receiving layer in which silicon pigments having different particle sizes are coated in two upper and lower layers together with an aqueous binder. JP-A-3-65376 discloses an ink-receiving layer containing a pigment having a specific specific surface area and an oil absorption. JP-A-3-27976 and the like disclose a solvent absorbing resin layer such as PVA and gelatin, a porous alumina hydrate layer,
An ink receiving layer in which a solvent absorbing layer made of silica gel and an opaque porous layer such as titanium oxide are laminated is disclosed.

However, in order to absorb the ink with the filler of the ink receiving layer, the thickness of the ink receiving layer must be considerably increased, and if the ink receiving layer is thickened, the mechanical strength of the recording paper is reduced. Further, when the ink receiving layer is composed of a layer having a large number of voids for absorbing or retaining the ink, the incident light is scattered or transmission is hindered, so that the gloss is hardly produced or the opaqueness is likely to occur. . Further, the dye in the ink permeates into the absorbing layer and is merely dried and fixed, and has no chemical bonding force with the absorbing layer. Therefore, there is a problem that the water resistance of the formed image is extremely poor.

[0008] On the other hand, there are many known ink jet recording papers of the type which absorbs and retains ink by a swelling action of a binder of an ink absorbing layer without providing a space by a filler in an ink receiving layer. For example, a hydrophilic binder such as gelatin, casein, starch, alginic acid, polyvinyl alcohol, various modified polyvinyl alcohols, polyvinylpyrrolidone, polyethylene oxide, polypropylene oxide, carboxymethylcellulose, hydroxyethylcellulose, dextran, and pullulan as a binder is coated on a support. Many recording papers, films, and the like have been conventionally known. These recording papers
Although the ink absorbing property is inferior to that of the recording paper having the above-mentioned voids, high glossiness, optical density, and clear images can be obtained, which is useful for high-quality recording applications.

For example, Japanese Patent Application Laid-Open No. 2-1359 discloses a transparent support provided with a hydrophilic layer in which a polyalkylene oxide and an amino group-inactivated gelatin (a so-called derivative gelatin) are used in combination. An ink jet recording paper having improved curl characteristics is described. Japanese Patent Application Laid-Open No. 6-247035 discloses that using spherical calcium alginate fine particles having high water retention and an aqueous resin, the printing is clear, the ink absorption is excellent, the contrast of the printing density is maintained, and the dot shape is improved. A high resolution inkjet recording paper is described. However, since the dye molecules are present alone in the binder, water droplets are applied to the recording surface, and the printed image is blurred when the image is stored for a long time under high humidity conditions after printing, and the dot size is increased. There was a disadvantage.

In order to solve these problems, attention is paid to the fact that a water-soluble dye having an anionic group such as a sulfonic acid group or a carboxylic acid group is generally mainly used in a jet ink. Numerous examples using a color dye fixing agent are disclosed. For example, Japanese Unexamined Patent Publication
JP-A-221115 discloses an ink-receiving layer containing a cationic water-soluble polymer together with an ink-absorbing binder resin. JP-A-6-183134, JP-A-6-234268 and JP-A-7-327
No. 25 discloses an ink receiving layer containing a cationic water-soluble polymer together with an ink-absorbing pigment and a binder resin. However, these cationic resins are originally water-soluble, and have a drawback that sufficient water resistance cannot be obtained. In addition, the cationic resin present on the surface when printing is redissolved in the ink, so that the surface shape of the printed part is roughened, the glossiness of the printed part is lost, and the sharpness of the image is reduced. There is a disadvantage that.

In order to improve these drawbacks, there is a technique using a water-insoluble cationic resin. For example, JP-A-7-17125 and JP-A-7-17127 disclose an ink receiving layer containing cationic colloid particles and inorganic oxide powder. JP 7
JP-A-137432 and JP-A-7-137433 disclose an ink receiving layer composed of particles having pores formed by reaggregating a dispersed cationic resin and a water-soluble binder resin. However, even in these cases, since the water-insoluble cationic resin is fixed to the water-soluble binder resin, it is difficult to say that the fixability is sufficient.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an ink having a high ink absorbing speed and a large absorbing capacity at the time of recording. In addition, an object of the present invention is to provide an ink jet recording medium capable of printing an image with high resolution, high density, and excellent water resistance without blurring of the image at a high speed.

[0013]

Means for Solving the Problems As a result of repeated studies for solving the above problems, the present inventors have found that the following structure can solve the problems, and have completed the present invention. That is, the present invention provides an ink jet recording medium comprising dye-fixing particles and a polysaccharide polymer gel crosslinked with polyvalent metal ions, wherein the dye-fixing particles are inorganic fine particles. The ink-jet recording medium, the dye-fixable particles are cationic polymer particles having a quaternary ammonium salt structure, wherein the recording medium is a cationic polymer particles having a quaternary ammonium salt structure, Structural formula

[0014]

Embedded image

(Wherein, R ₁ represents a hydrogen atom or a methyl group, R ₂ , R ₃ and R ₄ represent an alkyl group or an aralkyl group having 1 to 10 carbon atoms, and n represents 1 to 6 carbon atoms) R ₂ and R ₃ may be bonded to each other to form a ring, and X ⁻ represents a halogen ion or a —COO ⁻ group or —SO ₃ ^— group in the structure. Y represents a -COO- group or -CONR _5-
(Wherein, R ₅ represents a hydrogen atom or an alkyl group). The above-mentioned ink-jet recording medium or polysaccharide having a copolymer particle of a monomer having a quaternary ammonium salt structure and a hydrophobic monomer having no quaternary ammonium salt structure The above-mentioned ink jet recording medium, wherein the molecule is sodium alginate.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The dye-fixing particles used in the present invention are not particularly limited as long as they are cationic particles that can fix the dye in the ink. Examples of such dye-fixable particles include inorganic fine particles and cationic polymer particles having a quaternary ammonium salt structure.

Examples of the inorganic fine particles include, but are not limited to, inorganic fine particles such as alumina sol such as light calcium carbonate, heavy calcium carbonate, boehmite and pseudo-boehmite, colloidal alumina, cationic aluminum oxide and hydrates thereof. can do.

The cationic polymer particles having a quaternary ammonium salt structure include copolymer particles of a monomer having a quaternary ammonium salt structure and a hydrophobic monomer having no quaternary ammonium salt structure. However, it is preferable since the deterioration of light resistance is small and the dye fixing property is strong. 4
The monomer having a quaternary ammonium salt structure has the following structural formula

[0019]

Embedded image

(Wherein, R ₁ represents a hydrogen atom or a methyl group, R ₂ , R ₃ and R ₄ represent an alkyl group or an aralkyl group having 1 to 10 carbon atoms, and n represents 1 to 6 R ₂ and R ₃ may be bonded to each other at one end to form one ring, and X ⁻ represents a halogen ion or a —COO ⁻ group or a —SO ₃ ⁻ group in the structure. denotes an anion with, Y is, -COO- group or -CONR ₅
— (Wherein, R ₅ represents a hydrogen atom or an alkyl group)
Is shown. 4) of (meth) acrylic acid ester represented by
Grade ammonium salts are preferred.

In particular, in the above formula, R ₁ is preferably a hydrogen atom or a methyl group, R ₂ , R ₃ and R ₄ are preferably a methyl group, an ethyl group or a benzyl group, and n is 2-8.
X ⁻ is a chlorine ion, a bromine ion,
Sulfonate ions and alkyl sulfate ions are preferred.
Is preferably -COO- or -CONR _5, R ₅ is
A hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferred.

The quaternary ammonium salts of the (meth) acrylate represented by the above structural formula include dimethylaminoethyl acrylate, dimethylaminomethacrylate,
Compounds obtained by quaternizing diethylaminoethyl acrylate, diethylamino methacrylate, etc. with a quaternizing agent such as methyl chloride, ethyl chloride, benzyl chloride, methyl bromide, ethyl bromide, dimethyl sulfate, diethyl sulfate, methyl chloroacetate, etc. preferable.

The proportion of the monomer having a quaternary ammonium salt structure in all the monomers is preferably in the range of 1 to 70 mol%, more preferably in the range of 5 to 60 mol%. If the amount of the monomer is less than 1 mol%, dispersion stability and sufficient dye fixing property cannot be obtained, and if it exceeds 70 mol%, good dye fixing particles cannot be obtained and there is no dyeability. A mixture of particles and a polymer sol having a quaternary ammonium salt results.

As the hydrophobic monomer having no quaternary ammonium salt structure, one having a solubility in water of 0.1 to 1% is preferable. Copolymer particles having the composition ratio as charged can be obtained. Examples of such a hydrophobic monomer having no quaternary ammonium salt structure include ethyl methacrylate, butyl acrylate, isobutyl acrylate, methyl methacrylate, butyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, and n- Examples include alkyl esters of (meth) acrylic acid such as propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, and cyclohexyl acrylate. These four
Hydrophobic monomer having no quaternary ammonium salt structure These monomers may be used alone or in combination of two or more. When used alone, ethyl methacrylate or butyl acrylate is preferable, and when two or more types are used, the monomers exemplified above are preferably mixed and used as a mixture, and the solubility in water is as described above. It is preferable to control and use so as to be 0.1 to 1%.

The proportion of the hydrophobic monomer having no quaternary ammonium salt structure in all the monomers is preferably from 30 to 99 mol%, more preferably from 40 to 95 mol%. Hydrophobic monomer having no quaternary ammonium salt structure If the amount of the monomer is less than 30 mol%, good dye-fixing particles cannot be obtained, and if it exceeds 99 mol%, sufficient dyeability will be obtained. I can't get it.

The method for producing the cationic polymer particles having a quaternary ammonium salt structure is not limited to these, but may be a method obtained by emulsion polymerization, or a method in which a resin latex prepared by emulsion polymerization is aggregated so as to have an appropriate particle size. A method of obtaining a polymer, a method of dry-grinding a separately synthesized polymer, a method of grinding the polymer in a liquid in which the polymer is not dissolved or a method of emulsifying the polymer in the liquid, and a method of dissolving a uniformly dissolved polymer solution in a poor solvent. A known method such as a method of adding and precipitating can be used. Among these methods, the method using emulsion polymerization is particularly preferable because the steps are simple and no special equipment is required.

In the case of preparing cationic polymer particles having a quaternary ammonium salt structure by using emulsion polymerization, no surfactant is used and an initiator and a monomer having a quaternary ammonium salt structure are emulsified. It can be prepared by a so-called soap-free emulsion polymerization in which polymerization is carried out utilizing a stabilizing action, but it can also be prepared by ordinary emulsion polymerization performed by adding a surfactant. When a surfactant is added, a nonionic surfactant is preferred from the viewpoint of dispersion stability.

Examples of the nonionic surfactant include, for example,
Polyoxyethylene alkyl allyl ethers such as polyoxyethylene nonyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ethers, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, etc. Polyoxyethylene sorbitan esters, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, and other polyoxyethylene fatty acid esters, and oxyethylene / oxypropylene block copolymers. it can.

As the initiator, a conventionally used water-soluble initiator, for example, a peroxide-based water-soluble initiator or an azo-based water-soluble initiator can be used. Specific examples of the peroxide-based water-soluble initiator include ammonium persulfate, potassium persulfate, and hydrogen peroxide. Specific examples of the azo water-soluble agent include 2,2′-azobis [N- (2-hydroxyethyl) -2-methyl-propionamidine] dihydrochloride and 2,2′-azobis (2
-Amidinopropane) dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazoline-
2-yl) propane], 4,4′-azobis (4-cyanovaleric acid) and the like. When prepared by soap-free emulsion polymerization, particularly from the viewpoint of dispersion stability,
'-Azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], 2,2'-azobis {2-
Methyl-N- [1,1-bis (hydroxymethyl) -2
It is preferable to use an azoamide compound such as [-hydroxyethyl] -propionamide}. These initiators may be used as they are or after being dissolved in water or an aqueous solvent and charged into the reaction system.

The polysaccharide polymer is not particularly limited, but may be agar (agarose), carrageenan, sodium alginate, curdlan, pectin, konjac mannan, gellan gum, curdlan, xanthan gum, starch, galactomannan, nitrocellulose, pectinin, proteoglycan , Glycoprotein, Baygellan and the like. Among these, algin, alginic acid or a monovalent metal salt of alginic acid are preferable, and sodium alginate is particularly preferable, from the viewpoint of good ink absorbency and strong fixing of the dye-fixing resin particles.

The polyvalent metal ions include cesium ion, calcium ion, magnesium ion, strontium ion, barium ion, aluminum ion,
Examples include, but are not limited to, iron ions, copper ions, and vanadium oxide ions. There are preferable polyvalent metal ions depending on the type of polysaccharide polymer used,
For example, when sodium alginate is used, calcium ions, barium ions, and aluminum ions are preferred.

The ink jet recording medium of the present invention contains the above-mentioned dye-fixable particles and a polysaccharide polymer gel crosslinked with a polyvalent metal ion on and / or in a support. When these substances are contained on the support, the dye-fixing particles, the aqueous solution or dispersion of each of the polysaccharide polymer and the polyvalent metal salt are coated on the support, and gelation is performed. By drying, an ink receiving layer is formed on the support, and the ink jet recording medium of the present invention can be obtained. The expression “on the support” may be either the front surface or the back surface of the support.

As a method of applying these substances on a support and drying to form an ink receiving layer, for example, a roll coating method, a reverse coating method, a blade coating method, a rod-bar coating method, an air knife coating method, a spray method Known coating and drying methods such as a coating method and a curtain coating method can be used.

The coating amount of these substances in the ink-receiving layer in the inkjet recording medium is not particularly limited, but is preferably 1 to 100 g / m ^2, and more preferably set to 5 to 50 g / m ² approximately.

The support used in the ink jet recording medium of the present invention is not limited to these, but
For example, besides ordinary neutral or acidic high-quality paper, medium-quality paper, recycled paper, coated paper, art paper, etc., polyester fiber, polyamide resin, or polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate A polyolefin resin such as a copolymer can also be used. Such a support has a thickness of 10 to 200 μm.
m, a sheet having a basis weight of 10 to ²⁰⁰ g / m ² is preferable.

The support used for the ink jet recording medium of the present invention is not particularly limited as long as it has the above-mentioned ink receiving layer. It may have a layer.

Further, the ink jet recording medium of the present invention may contain, in a support, dye-fixable particles and a polysaccharide polymer gel crosslinked with polyvalent metal ions.

The ink receiving layer of the ink jet recording medium of the present invention may further contain at least one known white pigment. Examples of white pigments include calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, and synthetic amorphous Porous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite,
Examples include white inorganic pigments such as hydrohaloysite, magnesium carbonate, and magnesium hydroxide, and organic pigments such as styrene-based plastic pigments, acrylic-based plastic pigments, polyethylene, microcapsules, urea resins, and melamine resins.

Among the above-mentioned pigments, a white pigment is contained as a main component, so that it is preferably porous.
Preferable examples include porous synthetic amorphous silica, porous magnesium carbonate, and porous alumina. Among these, porous synthetic amorphous silica having a particularly large pore volume is preferable. The total amount of the above pigments can be appropriately adjusted in accordance with the characteristics of the intended ink jet recording medium.
It is preferably 5 to 60% by weight based on 0% by weight.

In the ink receiving layer, other additives such as a pigment dispersant, a thickener, a fluidity improver, an antifoaming agent, a foam inhibitor, a release agent, a foaming agent, a penetrating agent, a coloring dye A coloring pigment, a fluorescent whitening agent, an ultraviolet absorber, an antioxidant, an antiseptic, an antibacterial agent, a waterproofing agent, a wet paper strength enhancer, a dry paper strength enhancer, and the like can also be appropriately compounded.

[0041]

The present invention will be described in more detail with reference to the following examples. In addition, “parts” means “parts by weight” unless otherwise specified. (Synthesis Example 1 of Dye-Fixing Particles) In a 500 ml four-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen inlet tube, 37 g of ethyl methacrylate (hereinafter abbreviated as EMA) and methacrylic chloride. 17 g of ethyltrimethylammonium acidate (hereinafter abbreviated as METMAC)
Deionized water was added to make 188 g. At this time, the molar ratio of the monomers is EMA / METMAC = 80/20. Then, the contents in the flask were replaced with nitrogen while vigorously stirring the contents, and then heated to 80 ° C., and while maintaining the temperature, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl)- Propionamide] (VA-08
6: manufactured by Wako Pure Chemical Industries, Ltd.), 60 g of a 2% aqueous solution was added, polymerization was carried out for 3 hours, and water-soluble impurities in the reaction solution were removed by ultrafiltration to obtain dye-fixing particles.

Example 1 A coating liquid (solid content: 2%) consisting of an aqueous solution of sodium alginate (average molecular weight: 80,000) was prepared, and commercially available high-quality paper (basis weight: 81 g / m ² , paper thickness: 80 μm)
m), and apply 100 parts (20% solids) of an aqueous dispersion of light calcium carbonate (Luminous: manufactured by Maruo Calcium Co.) to the dry weight of 5 g / m ^2. Was applied to be 3 g / m ² . further,
A 2% by weight aqueous solution of calcium chloride is applied on this,
Gelation of sodium alginate was performed. This was dried to obtain the ink jet recording medium of the present invention.

Example 2 A coating liquid A was prepared by adding 2 parts of calcium chloride to 100 parts (solid content: 20%) of the aqueous dispersion of dye-fixing particles obtained in Synthesis Example 1 and dissolving it. on the other hand,
A coating liquid B (solid content concentration: 2%) composed of an aqueous solution of sodium alginate (average molecular weight: 80,000) was prepared, and dried on a commercial high-quality paper (basis weight: 81 g / m ² , paper thickness: 80 μm) with a dry weight of 5 g / m ^2, and then the above-mentioned coating solution A was applied thereon such that the dry weight was 3 g / m ² .
At the same time as the coating liquid A was applied, the sodium alginate gelled. This was dried to obtain the ink jet recording medium of the present invention.

(Example 3) A commercially available untreated polyester film (film for OHP: manufactured by Konan Rubber Co., Ltd.) was used in place of the high quality paper, and a modified polyolefin resin (Dumilan D-251S manufactured by Takeda Pharmaceutical Co., Ltd.) was used. After coating and drying at 0.1 g / m ² , coating liquids A and B were applied in the same manner as in Example 2 to obtain an ink jet recording medium of the present invention.

(Synthesis Example 2 of Dye Fixing Particles) Instead of EMA, 32 g of methyl methacrylate (hereinafter abbreviated as MMA) was used, and instead of METMAC, ethylbenzyldimethylammonium methacrylate chloride (hereinafter, referred to as MMA).
MMA / ME using 23 g (abbreviated as MEBMAC)
Dye-fixing particles were obtained in the same manner as in Synthesis Example 1 of the dye-fixing particles, except that BMAC was set to 80/20.

Example 4 A coating liquid A was prepared by adding 2 parts of calcium chloride to 100 parts (solid content: 20%) of the aqueous dispersion of dye-fixing particles obtained in Synthesis Example 2 above and dissolving it. On the other hand, a coating liquid B (solid content: 2%) composed of an aqueous solution of a 1: 1 mixture of sodium alginate (average molecular weight: 80,000) and porous synthetic amorphous silica was prepared, and commercially available high-quality paper (basis weight) 81 g / m ² , paper thickness 80 μm) and a dry weight of 5 g / m ²
m ^2, and then the coating solution A
Was applied so that the dry weight was 3 g / m ² . At the same time as the coating liquid A was applied, the sodium alginate gelled. This was dried to obtain the ink jet recording medium of the present invention.

Comparative Example 1 An ink jet recording medium was obtained in the same manner as in Example 1 except that no dye-fixing particles were used.

Comparative Example 2 An ink jet recording medium was obtained in the same manner as in Example 1 except that calcium chloride was not used.

Comparative Example 3 An ink jet recording medium was obtained in the same manner as in Example 2 except that no dye-fixing particles were used.

Comparative Example 4 An ink jet recording medium was obtained in the same manner as in Example 2 except that calcium chloride was not used.

Comparative Example 5 An ink jet recording medium was obtained in the same manner as in Example 4 except that no dye-fixing particles were used.

Comparative Example 6 An ink jet recording medium was obtained in the same manner as in Example 4 except that calcium chloride was not used.

(Test Example 1) Examples 1 to 3 and Comparative Example 1
Test printing was performed using an ink jet printer MJ-800 (manufactured by Seiko Epson Corporation) under the standard environment of 20 ° C. and 60% RH using the seven types of ink jet recording media obtained in Nos. 4 to 4.

Evaluation of Drying Speed The test printing portion was touched with a finger 10 seconds after printing, and the drying speed was determined based on the degree of ink contamination on the finger, and evaluated with △, Δ, and ×.

Evaluation of Image Quality The test print area was observed with a 25-fold loupe, and the reproducibility and bleeding of dots were visually determined, and the image quality was evaluated based on the following evaluation criteria. A: No bleeding, good dot shape. B: Slight bleeding is recognized, but there is no practical problem. C: Bleeding is noticeable, the dot shape is poor, and there is a problem in practical use. D: A level at which the dot shape collapses due to bleeding and is not practical.

Evaluation of Water Resistance A water droplet of 0.1 ml was dropped on the printed portion, observed in the same manner with a loupe, and bleeding was visually judged, and the water resistance was evaluated based on the same evaluation criteria as the evaluation criteria of the image quality. Table 1 shows the results.

[0057]

[Table 1]

As is clear from the results shown in Table 1,
The inkjet recording medium of the present invention (Examples 1 to 3)
The drying speed of the ink was fast, the image quality was excellent without bleeding, etc., and the water resistance was also excellent. On the other hand, in Comparative Examples 1 and 3 using no dye-fixing particles and Comparative Examples 2 and 4 in which the polysaccharide polymer was not crosslinked by polyvalent metal ions, the drying speed, image quality, and water resistance were poor. there were.

[0059]

The ink jet recording medium of the present invention has a high ink absorption speed during recording, has a large absorption capacity, is free from bleeding, has a high resolution, a high density, and has excellent water resistance. It is possible to print with.

Continued on the front page F term (reference) 2H086 BA19 BA31 BA34 4J100 AL03Q AL04Q AL05Q AL08P AL08Q BA32P BC04Q CA04 JA01 JA13

Claims (8)

[Claims] 1. An ink jet recording medium comprising dye-fixable particles and a polysaccharide polymer gel crosslinked with a polyvalent metal ion. 2. The ink jet recording medium according to claim 1, wherein the dye fixing particles are inorganic fine particles. 3. The ink jet recording medium according to claim 1, wherein the dye fixing particles are cationic polymer particles having a quaternary ammonium salt structure. 4. The cationic polymer particles having a quaternary ammonium salt structure have the following structural formula: (Wherein, R ₁ represents a hydrogen atom or a methyl group, and R ₂ ,
R ₃ and R _{4 each} represent an alkyl group or an aralkyl group having 1 to 10 carbon atoms, n represents an integer of 1 to 6, and R ₂ and R ₃ form a ring by combining their terminals. X ⁻ may be a halogen ion or —C in the structure.
An anion having an OO ^- group or a -SO ₃ ^- group;
Y represents a —COO— group or —CONR ₅ — (wherein R is
₅ represents a hydrogen atom or an alkyl group). 4. The ink jet recording medium according to claim 3, wherein the particles are copolymer particles of a monomer having a quaternary ammonium salt structure and a hydrophobic monomer having no quaternary ammonium salt structure. 5. The ink jet recording medium according to claim 4, wherein the monomer having a quaternary ammonium salt structure is a quaternary ammonium salt of (meth) acrylate. 6. The ink jet recording medium according to claim 4, wherein the hydrophobic monomer having no quaternary ammonium salt structure is an alkyl ester of (meth) acrylic acid. 7. The ink jet recording medium according to claim 1, wherein the polysaccharide polymer is sodium alginate. 8. The polyvalent metal ion is a calcium ion,
Barium ion, aluminum ion, cesium ion,
2. The ink jet recording medium according to claim 1, wherein the medium is selected from magnesium ions, strontium ions, iron ions, copper ions and vanadium oxide ions.