JPH06143797A - Ink-jet recording medium - Google Patents

Abstract

PURPOSE:To provide an ink-jet recording medium which has swift absorption of ink and is superior in fixing properties. CONSTITUTION:This is an ink-jet recording medium which is comprised by combining ink for ink-jet recording containing metallic salt having a lower metallic ionization row than those of colored dyes, a pigment and magnesium and ink-jet recording paper containing alkali metals or alkaline earth metallic salts of a cellulose derivative comprised of calboxymethylcellulose or calboxyethylcellulose within an ink receiving layer and containing respectively specific quantities of the metallic salts in the ink and the cellulose derivative in the receiving layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording medium, more specifically, a combination of a particular ink jet recording ink and the recording paper,
The present invention relates to an inkjet recording medium that has high ink absorbency and excellent fixability.

[0002]

2. Description of the Related Art The ink jet recording method is a method for ejecting minute droplets of ink to adhere to a recording sheet such as paper by various operating principles to record images, characters, etc., but at high speed and low noise. It has features such as easy multicoloring, great flexibility in recording patterns, and no need for development and fixing. It has rapidly spread in various applications as a recording device for various figures and color images including Chinese characters. There is. Furthermore, images formed by the multi-color inkjet method can obtain records that are comparable to those of multi-color printing by the plate-making method and printing by the color photographic method. Since it is cheaper than the technology, it is being widely applied to the field of full-color image recording.

As recording paper used in this ink jet recording system, efforts have been made from the viewpoint of the apparatus and ink composition so as to use high-quality paper or coated paper used for ordinary printing and writing. However, with the improvement of the performance of the inkjet recording apparatus and the expansion of its uses such as the speeding up of the apparatus, the high definition and the full color, the recording paper is required to have higher characteristics. That is, as the recording paper, the density of print dots is high, the color tone is bright and vivid, the ink does not flow out or bleed even when the print dots are overlapped and the print dots overlap, and the horizontal direction of the print dots. It is required that the diffusion of light into the surrounding area is not unnecessarily large and that the surrounding area is smooth and does not blur.

Further, when the recorded image after recording is wet with water, it is demanded that the recording paper does not bleed out to be soiled or decolored, and further discolored by exposure to light, ozone gas, oxidizing gas, etc. It is necessary to use recording paper that does not easily fade.

Among these various characteristics, there is JP-A-55-53591 for the purpose of water resistance of a recorded image.
This publication discloses a recording paper in which a water-soluble salt of a metal consisting of calcium, magnesium, aluminum, iron, cobalt, nickel, copper and zinc is provided on the surface of the recording paper. As the ink, a dye containing a carboxyl group or a sulfonic acid group in the dye is used. In recording, a dye and a water-soluble metal salt of the recording paper react to form a sparingly soluble salt, which is characterized by a combination of a water-soluble metal salt and a specific dye. However, in this publication, it is necessary to use a specific dye containing a carboxyl group or a sulfonic acid group in the molecule, especially a sodium salt thereof, and the range of use of the dye is naturally limited.

Further, there is Japanese Patent Application Laid-Open No. 61-287782 filed by the applicant of the present invention for the purpose of absorbing and drying ink, which is a recording sheet for an overhead projector. This publication discloses a recording sheet in which an ink receiving layer containing a water-soluble cellulose derivative is provided on a transparent support. Among the water-soluble cellulose derivatives, it is described that methyl cellulose and hydroxypropyl methyl cellulose are particularly preferable. However, in this publication, the ink receiving layer contains a water-soluble cellulose derivative,
It is intended to obtain an ink receiving layer having good light transmittance,
The cellulose derivative itself is characterized by its transparency.

[0007]

The above publications all disclose recording sheets containing a water-soluble metal salt or a cellulose derivative for the purpose of water resistance of a recorded image or light transmission of an ink receiving layer. However, it is not a combination of each of these components. The inkjet recording medium of the present invention is intended to improve the ink absorbability and fixability by incorporating the above-mentioned components in the inkjet recording ink and the inkjet recording paper.

[0008]

As a result of intensive studies, the inventor of the present invention has come to invent the ink jet recording medium of the present invention. That is, the inkjet recording medium of the present invention,
An ink jet recording ink containing a colored dye and a metal salt having a metal ionization sequence lower than that of magnesium, and an ink jet recording containing an alkali metal or alkaline earth metal salt of a cellulose derivative consisting of carboxymethyl cellulose or carboxyethyl cellulose in the ink receiving layer. An ink jet recording medium in which a paper is combined, and the metal salt is contained in the ink in an amount of 0.05
The content of the alkali metal salt or alkaline earth metal salt of the cellulose derivative is 3 to 20% by weight in the ink receiving layer.

The ink jet recording medium of the present invention will be described in detail below.

The ink jet recording medium of the present invention comprises a metal salt having a metal ionization sequence lower than that of magnesium in the ink, and the cellulose derivative contained in the ink receiving layer of the recording paper. By the chelate reaction between the cellulose derivative and the cellulose derivative, the fixability of the recorded image is exhibited. At the same time, ink absorbency is also imparted.

In the ink jet recording medium of the present invention, the cellulose derivative in the ink jet recording paper is an alkali metal or alkaline earth metal salt of a cellulose derivative consisting of carboxymethyl cellulose and carboxyethyl cellulose. Here, the alkali metal or alkaline earth metal salt is one or more metal salts selected from the group consisting of sodium, potassium and calcium.

In the ink jet recording paper of the present invention, the alkali metal or alkaline earth metal salt of the cellulose derivative contained in the ink receiving layer is 3 to 20% by weight. Here, if the content is less than 3% by weight, the fixability with the metal salt in the inkjet recording ink is poor, which is not preferable. On the other hand, if the amount is more than 20% by weight, it is inefficient because the amount is excessive with respect to the ink for ink jet recording, and further it causes poor adhesion of the ink receiving layer, which is not preferable.

The ink jet recording ink of the present invention comprises
It is composed of a colored dye and pigment and a metal salt having a metal ionization sequence lower than that of magnesium. Examples of the metal salt include one or more metal salts selected from the group consisting of copper sulfate, zinc sulfate, aluminum sulfate, barium chloride, stannous chloride and ferric chloride. Among these metal salts, preferred are copper sulfate, aluminum sulfate and zinc sulfate.

In the ink for ink jet recording, a metal salt having a metal ionization sequence lower than that of magnesium is
It is contained in an amount of 0.05 to 5% by weight in the total amount of ink. Here, if it is less than 0.05% by weight, the fixability of the cellulose derivative with an alkali metal or an alkaline earth metal is poor, which is not preferable. On the other hand, if the amount exceeds 5% by weight, the stability of the ink is deteriorated, which is not preferable.

The ink for inkjet recording contains 1 to 10% by weight of a colored dye or pigment in the total amount of the ink. Here, if it is less than 1% by weight, the density of the recorded image is low, and if it exceeds 10% by weight, ink is clogged at the ejection orifice provided in the recording head, which is not preferable.

The colored dyes and pigments used in the present invention include:
For example:

Colored dyes include direct dyes, acid dyes,
There are basic dyes, reactive dyes, and water-soluble dyes such as food dyes.

For example, as a direct dye, CI Direct Black: 2,4,9,11,14,17,19,22,27,32,36,38,
41,48,49,51,56,62,71,74,75,77,78,80,105,106,107,10
8,112,113,117,132,146,154,194 CIDirect Yellow: 1,2,4,8,11,12,24,26,27,28,33,34,
39,41,42,44,48,50,51,58,72,85,86,87,88,98,100,110 CIDirect Orange: 6,8,10,26,29,39,41,49,51,102 CIDirect Red: 1,2,4,8,9,11,13,17,20,23,24,28,31,3
3,37,39,44,46,47,48,51,59,62,63,73,75,77,80,81,83,
84,85,90,94,99,101,108,110,145,189,197,220,224,22
5,226,227,230 CIDirect Violet: 1,7,9,12,35,48,51,90,94 CIDirect Blue: 1,2,6,8,15,22,25,34,69,70,71,72,7
5,76,78,80,81,82,83,86,90,98,106,108,110,120,123,1
58,163,165,192,193,194,195,196,199,200,201,202,20
3,207,218,236,237,239,246,258 CIDirect Green: 1,6,8,28,33,37,63,64 CIDirect Brown: 1A, 2,6,25,27,44,58,95,100,101,10
6,112,173,194,195,209,210,211

Examples of acid dyes include CIAcid Black: 1,2,7,16,17,24,26,28,31,41,48,52,5
8,60,63,94,107,109,112,118,119,121,122,131,155,156 CIAcid Yellow: 1,3,4,7,11,12,13,14,17,18,19,23,2
5,29,34,36,38,40,41,42,44,49,53,55,59,61,71,72,76,
78,99,111,114,116,122,135,161,172 CIAcid Orange: 7,8,10,33,56,64 CIAcid Red: 1,4,6,8,13,14,15,18,19,21,26,27,30,3
2,34,35,37,40,42,51,52,54,57,80,82,83,85,87,88,89,
92,94,97,106,108,110,115,119,129,131,133,134,135,1
54,155,172,176,180,184,186,187,249,254,256,317,318 CIAcid Violet: 7,11,15,34,35,41,43,49,75 CIAcid Blue: 1,7,9,22,23,25,27,29,40,41,43,45,49,
51,53,55,56,59,62,78,80,81,83,90,92,93,102,104,11
1,113,117,120,124,126,145,167,171,175,183,229,234,
236 CIAcid Green: 3,12,19,27,41,9,16,20,25 CIAcid Brown: 4,14

Examples of the basic dye include CIBasic Black: 2,8 CIBasic Yellow: 1,2,11,12,14,21,32,36 CIBasic Orange: 2,15,21,22 CIBasic Red: 1, 2,9,12,13,37 CIBasic Violet: 1,3,7,10,14 CIBasic Blue: 1,3,5,7,9,24,25,26,28,29 CIBasic Green: 1,4 CIBasic Brown: 1,12 As a reactive dye, for example, CIReactive Black: 1,3,5,6,8,12,14 CIReactive Yellow: 1,2,3,13,14,15,17 CIReactive Orange: 2, 5,7,16,20,24 CIReactive Red: 6,7,11,12,15,17,21,23,24,35,36,4
2,63,66 CIReactive Violet: 2,4,5,8,9 CIReactive Blue: 2,5,7,12,13,14,15,17,18,19,20,2
1,25,27,28,37,38,40,41 CIReactive Green: 5,7 CIReactive Brown: 1,7,16

Further, as a food dye, for example, CIFood Black: 2 CIFood Yellow: 3,4,5 CIFood Red: 2,3,7,9,14,52,87,92,94,102,104,105,10
6 CIFood Violet: 2 CIFood Blue: 1,2 CIFood Green: 2,3.

Examples of the colored pigment include inorganic pigments and organic pigments. Examples of the inorganic pigment include red iron oxide,
There are oxides such as cobalt blue, sulfides such as cadmium yellow and cadmium red, ferrocyanides such as dark blue, silicates such as ultramarine, phosphates such as manganese violet and carbon black.

Examples of the organic pigments include nitroso pigments such as naphthol yellow S, azo pigments such as resole red, disazo red and chromophthal red, dye lake pigments such as alkali blue lake methyl violet lake, and phthalocyanine such as phthalocyanine blue. There are pigments, etc.

Examples of oil-soluble dyes include monoazo dyes, disazo dyes, metal complex salt type monoazo dyes, anthraquinone dyes, phthalocyanine dyes, triallylmethane dyes and the like.

As the solvent for the aqueous ink, water and various water-soluble organic solvents are used. For example, alkyl alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol isobutyl alcohol; dimethylformamide, dimethylacetamide, etc. Amides; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-Hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol and other alkylene groups having 2 to 6 alkylene groups. Chelating glycol ethers; glycerol, ethylene glycol methyl ether diethylene glycol methyl (or ethyl) ether, lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether, and the like. Among these many water-soluble organic solvents,
Preferred are polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether.

Other additives include, for example, a pH adjusting agent, a sequestering agent, an antifungal agent, a viscosity adjusting agent, a surface tension adjusting agent, a wetting agent, a surfactant, or a rust preventive agent.

Examples of the support used in the present invention include paper mainly composed of wood fibers, and sheet-like substances such as non-woven fabric mainly composed of wood fibers and synthetic fibers. In the case of paper, with or without addition of internal sizing agent, neutral sizing agent,
A sizing agent such as a polymer sizing agent and an acidic sizing agent may be used alone or in combination, and a filler may be contained or not contained, and there is no limitation with or without size pressing.

As the internal filler for the paper support, conventionally known pigments are used as white pigments, and they can be used alone or in combination. For example, light calcium carbonate, heavy calcium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate,
White such as titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic silica, aluminum hydroxide, alumina, lithopone, zeolite, magnesium carbonate, magnesium hydroxide Examples thereof include inorganic pigments, styrene plastic pigments, acrylic plastic pigments, polyethylene, microcapsules, organic pigments such as urea resins and melamine resins.

In the present invention, one or more known white pigments may be used in the ink receiving layer. For example,
Light calcium carbonate, heavy 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, synthetic amorphous silica, colloidal silica,
Colloidal alumina, pseudo-boehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrohalloysite, magnesium carbonate, white inorganic pigments such as magnesium hydroxide, styrene plastic pigment, acrylic plastic pigment, polyethylene microcapsule, urea resin, melamine resin And other organic pigments. Among the above, the white pigment contained as the main component in the ink receiving layer is preferably a porous inorganic pigment,
Examples thereof include porous synthetic amorphous silica, porous magnesium carbonate, and porous alumina. Particularly, porous synthetic amorphous silica having a large pore volume is preferable.

Examples of the adhesive used in the ink receiving layer of the present invention include the following. For example, polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, carboxymethyl cellulose, cellulose derivatives such as hydroxyethyl cellulose, casein, gelatin,
Soybean protein, silyl modified polyvinyl alcohol, etc .; Conjugated diene copolymer latex such as maleic anhydride resin, styrene-butadiene copolymer, methylmethacrylate-butadiene copolymer; polymer or copolymer of acrylic acid ester and methacrylic acid ester Acrylic polymer latex such as polymer; vinyl polymer latex such as ethylene-vinyl acetate copolymer; or functional group-modified polymer latex with a functional group-containing monomer such as carboxyl group of these various polymers; melamine Water-based adhesives such as thermosetting synthetic resins such as resins and urea resins; synthetic resin adhesives such as polymethylmethacrylate, polyurethane resins, unsaturated polyester resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral and alkyd resins. Used in one or more kinds. Of these, water-soluble polymer binders are preferably used in the present invention.

One or more cationic dye fixing agents can be used in the ink receiving layer of the present invention. The cationic dye fixing agent is a monomer, oligomer or polymer of a primary to tertiary amine or a quaternary ammonium salt that disintegrates when it is dissolved in water to exhibit a cationic property, and is preferably an oligomer or polymer.

In the present invention, other additives include
Pigment dispersant, thickener, fluidity improver, defoamer, foam suppressor,
Release agents, foaming agents, penetrants, coloring dyes, coloring pigments, optical brighteners, ultraviolet absorbers, antioxidants, preservatives, antifungal agents,
A water resistance agent, a wet paper strength enhancer, a dry paper strength enhancer and the like can be appropriately blended.

As a method for producing the ink jet recording sheet of the present invention, for example, pulp fibers are disintegrated into a slurry, and if necessary, a filler, a sizing agent and other additives are added, papermaking is carried out by a paper machine and dried. Alternatively, after the papermaking, an aqueous solution of starch or a polymer substance is size-pressed, dried and machine-calendered to obtain a support sheet, and at least one layer or more is applied using a coating device or a size press device. An ink receiving layer is provided. The maximum heating temperature of the dryer is at least 100 ° C or higher, preferably 120 ° C or higher. It is preferable that the temperature is high in relation to the drying efficiency, but the temperature is not particularly limited. The machine calendar may or may not be used, but it is preferably used in consideration of workability in the next coating step.

The coating machine for coating the ink receiving layer may be either an on-machine coater or an off-machine coater. For example, conventionally known air knife coaters, curtain coaters, die coaters, blade coaters, gate roll coaters, bar coaters, rod coaters, roll coaters, bill blade coaters, short dwell blade coaters and the like can be used. Further, after coating, finish using a calendar such as a machine calendar, super calendar, or soft calendar.

[0035]

The inkjet recording medium of the present invention comprises an inkjet recording ink containing a colored dye and a pigment and a metal salt having a metal ionization sequence lower than that of magnesium, and an alkali metal or alkaline earth metal of a cellulose derivative consisting of carboxymethyl cellulose and carboxyethyl cellulose. It is a combination of an inkjet recording paper containing a salt in the ink receiving layer and utilizes a chelate reaction between the metal salt and the cellulose derivative. Upon recording, the ink for ink jet recording containing the metal salt comes into contact with the cellulose derivative in the ink receiving layer and instantly exhibits a chelate reaction. The ink in the ink receiving layer absorbs and fixes in a short time. As a result, the recorded image can have excellent fixability, that is, image stability.

[0036]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.
In addition, "parts" and "%" shown in the examples represent parts by weight and% by weight, unless otherwise specified.

Example 1 1. Manufacture of base paper LBKP beaten to a freeness of 380 ml (CSF) and NBKP beaten to a freeness of 450 ml (CSF) were mixed in a ratio of 7: 3 by weight ratio to 100 parts of a pulp of light calcium carbonate (commodity). Name; TP121, Okutama Kogyo Co., Ltd.) 10 parts, sulfuric acid band as a solid content 0.6
, 0.8 parts of amphoteric starch (trade name; Kate 3210, manufactured by Oji National Co., Ltd.), and 0.06 part of AKD sizing agent (trade name; size pine K903, manufactured by Arakawa Chemical Co., Ltd.) as a solid component, Papermaking was carried out using a Ford Linear type paper machine to produce a base paper having a basis weight of 64 g / m ² .

2. Manufacture of inkjet recording paper Using the base paper having a basis weight of 64 g / m ² prepared in 1 above, a solid content of 8 g / m ^{2 of a} coating solution having a concentration of 15% on one side of the base paper is prepared as follows. As described above, coating was performed using an air knife coater, and a super calender finish was applied to produce an inkjet recording paper. Synthetic amorphous silica (trade name: Fineseal X-37B, manufactured by Tokuyama Soda Co., Ltd.) 50 parts Light calcium carbonate (trade name: Callite KT, manufactured by Shiraishi Calcium Co., Ltd.) 15 parts Polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray Co., Ltd.) ) 15 parts Natrirum salt of carboxymethyl cellulose 10 parts Cation resin (trade name: Sumirezuregen 1001, manufactured by Sumitomo Chemical Co., Ltd.) 10 parts

3. Preparation of Inkjet Recording Ink The inkjet recording ink was prepared by the following formulation. C. I. Direct Blue 6 2 parts Copper sulfate 0.1 part Ethylene glycol 40 parts Water 57.9 parts

Example 2 0.1 part of copper sulfate and 57.5 parts of water used in Example 1 were
An ink jet recording ink was prepared in the same manner as in Example 1 except that the amount was set to 1 part and 57 parts, respectively.

Example 3 0.1 part of copper sulfate and 57.9 parts of water used in Example 1 were used.
An ink jet recording ink was prepared in the same manner as in Example 1 except that the amounts were 5 parts and 53 parts, respectively.

Example 4 0.1 part of copper sulfate and 57.9 parts of water used in Example 1 were
An inkjet recording ink was prepared in the same manner as in Example 1 except that the amounts were 0.05 part and 57.95 part, respectively.

Comparative Example 1 0.1 part of copper sulfate and 57.9 parts of water used in Example 1 were used.
An inkjet recording ink was prepared in the same manner as in Example 1 except that the amounts were 0.04 part and 57.96 part, respectively.

Comparative Example 2 0.1 part of copper sulfate and 57.9 parts of water used in Example 1 were used.
An inkjet recording ink was prepared in the same manner as in Example 1 except that the amounts were 5.5 parts and 52.5 parts, respectively.

Example 5 15 parts of polyvinyl alcohol and sodium salt of carboxymethylcellulose 1 in the ink receiving layer formulation of Example 1
An inkjet recording paper was produced in the same manner as in Example 1 except that 0 part was 5 parts of polyvinyl alcohol and 20 parts of potassium salt of carboxyethyl cellulose. In addition, the ink jet recording ink was prepared as follows. C. I. Direct Blue 6 2 parts Aluminum sulfate 0.5 part Ethylene glycol 40 parts Water 57.5 parts

Example 6 15 parts of polyvinyl alcohol and sodium salt of carboxymethyl cellulose 1 in the ink receiving layer formulation of Example 1
An inkjet recording paper was produced in the same manner as in Example 1 except that 0 part was 20 parts of polyvinyl alcohol and 5 parts of potassium salt of carboxyethyl cellulose.

Example 7 15 parts of polyvinyl alcohol and sodium salt of carboxymethyl cellulose 1 in the ink receiving layer formulation of Example 1
An ink jet recording paper was produced in the same manner as in Example 1 except that 0 part was replaced with 22 parts of polyvinyl alcohol and 3 parts of potassium salt of carboxyethyl cellulose.

Comparative Example 3 15 parts of polyvinyl alcohol and sodium salt of carboxymethyl cellulose in the ink receiving layer of Example 1 were mixed.
An inkjet recording paper was produced in the same manner as in Example 1 except that 0 part was replaced with 25 parts of potassium salt of carboxyethyl cellulose alone.

Comparative Example 4 15 parts of polyvinyl alcohol and sodium salt of carboxymethylcellulose 1 in the ink receiving layer of Example 1 were blended.
An ink jet recording paper was produced in the same manner as in Example 1 except that 0 part was 3 parts of polyvinyl alcohol and 22 parts of potassium salt of carboxyethyl cellulose.

Comparative Example 5 15 parts of polyvinyl alcohol and sodium salt of carboxymethylcellulose 1 in the ink receiving layer of Example 1 were blended.
An inkjet recording paper was produced in the same manner as in Example 1 except that 0 part was 22.5 parts of polyvinyl alcohol and 2.5 parts of potassium salt of carboxyethyl cellulose.

Comparative Example 6 15 parts of polyvinyl alcohol and sodium salt of carboxymethylcellulose 1 in the ink receiving layer of Example 1 were blended.
An inkjet recording paper was produced in the same manner as in Example 1 except that 0 part was replaced with 25 parts by itself of polyvinyl alcohol.

Evaluation: The ink jet recording ink prepared in each of the above Examples and Comparative Examples was filled in a cartridge for an ink jet printer (model name: IO-720, manufactured by Sharp Corporation) and mounted in the printer. It was printed on the manufactured inkjet recording paper. The ink jet recording ink prepared in Example 1 was used for the ink jet recording paper of Examples 1 to 4 and Comparative Examples 1 and 2, and the ink jet recording ink prepared in Example 5 was used in Examples 5 to 7 And the inkjet recording papers of Comparative Examples 3 to 6 were used.

[Ink Absorbency] When the ink absorbency was printed by an ink jet printer, the ink bleeding condition at the boundary of the printed portion was visually observed, and ◯ was good, Δ was slightly good (within a practical range), x Was evaluated as defective.

[Ink Fixability] The ink fixability is determined by immersing the printed part in water at 25 ° C. and visually observing the flow condition of the printed image. Good ○, good Δ (within practical range), and bad X. It was evaluated as defective.

[0055]

[Table 1]

Evaluation results; Examples 1-4 and Comparative Examples 1-2
In this case, the amount of copper sulfate in the inkjet recording ink is changed while the inkjet recording paper is kept constant. In Examples 1 to 4, the results were that the ink absorbency and the ink fixability were good because they were within the scope of the present invention. On the other hand, in Comparative Example 1, the amount of copper sulfate in the ink for inkjet recording was out of the range, the ink absorbability was somewhat good, but the ink fixability was poor. Comparative example 2
However, the amount of copper sulfate in the ink for ink jet recording was large, an agglomerated state was generated, the ink head was clogged, and printing could not be performed. Moreover, Examples 5 to 7 and Comparative Examples 3 to
In No. 6, the amount of the potassium salt of carboxyethyl cellulose in the inkjet recording paper was changed while the inkjet recording ink was kept constant. In Examples 5 to 7, the results were that the ink absorbability and the ink fixability were good because they were within the scope of the present invention. On the other hand, in Comparative Example 3 and Comparative Example 4, the content of the potassium salt of carboxyethyl cellulose was large, and although the ink absorbability was good, the ink fixability was unfavorable because the coating layer peeled off. In Comparative Example 5, the content of the potassium salt of carboxyethyl cellulose was small, and in Comparative Example 6, the ink absorbability and the ink fixability were poor because the potassium salt of carboxyethyl cellulose was not used.

[0057]

The inkjet recording medium of the present invention is a combination of an inkjet recording ink containing a specific metal salt and an inkjet recording paper containing a specific metal salt of a cellulose derivative. An ink jet recording medium having excellent ink fixability could be obtained.

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Claims (3)

[Claims] 1. An ink-jet recording ink containing a colored dye / pigment and a metal salt having a metal ionization sequence lower than that of magnesium, and an alkali metal or alkaline earth metal salt of a cellulose derivative consisting of carboxymethyl cellulose or carboxyethyl cellulose in an ink receiving layer. An inkjet recording medium in combination with the inkjet recording paper according to claim 1, wherein the metal salt is contained in the ink in an amount of 0.05 to 5% by weight, and an alkali metal or alkaline earth metal salt of the cellulose derivative. Is contained in the ink receiving layer in an amount of 3 to 20% by weight. 2. The metal salt having a metal ionization sequence lower than that of magnesium is one or more metal salts selected from the group consisting of copper sulfate, zinc sulfate, aluminum sulfate, barium chloride, stannous chloride and ferric chloride. The inkjet recording medium according to claim 1, wherein 3. The ink jet recording according to claim 1, wherein the alkali metal or alkaline earth metal salt of the cellulose derivative is one or more metal salts selected from the group of sodium, potassium and calcium. Medium.