JP2001310549A - Material to be recorded for ink-jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material to be recorded for an ink-jet which is excellent in light fastness and water resistance. SOLUTION: The material is the recording material for an ink-jet containing acid having sulfonic group in an ink reception layer of a support or/and a base of the acid, that is, the recording material for the ink-jet of which solubility of the acid and base to water is not less than 4 g in saturated solution of 100 g at 20 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material which can be used for various ink jet printers. In particular, the present invention relates to a recording material excellent in light resistance and water resistance.

[0002]

2. Description of the Related Art Ink-jet recording systems are rapidly becoming personal use and business due to the fact that full-color printing is easy, noise is low, high-resolution images can be obtained at low cost, and high-speed printing is possible. It is becoming popular in both youth. At present, the mainstream of the ink jet recording systems is a recording system using an aqueous ink, and a printed matter having a very high resolution has been obtained at present. Conventionally, general paper has been used as a recording material used in the ink jet recording method using the aqueous ink.

However, with the improvement of printer performance such as high-speed printing and multi-color printing, and expansion of applications, higher characteristics are required for ink jet recording materials. For example, the printed matter has a drawback that the ink itself is water-based and thus has poor water resistance and an image flows with water as it is, and improvement is desired.

In recent years, attempts have been made to add various cationic polymers in order to improve the water resistance of the recording sheet. For example, polyethyleneimine (Japanese Unexamined Patent Publication No.
6-89992), dimethyldiallylammonium chloride (JP-A-59-20696), polyallylamine hydrochloride (JP-A-62-174184), and polyvinylamine homopolymer (JP-A-64-8).
No. 085).

[0005]

However, the addition of these cationic polymers improves the water resistance, but conversely reduces the light resistance. There has been a demand for the development of a new additive for preventing odor.

[0006]

Means for Solving the Problems Investigations have been made by the researchers as a result of the research. As a result, by adding a specific additive to the ink jet recording medium in the ink receiving layer, the ink jet recording medium having excellent light resistance is obtained. Have been found, and have led to the present invention. That is, the gist of the present invention is to provide an ink jet recording material containing an acid having a sulfonic acid group and / or a salt of the acid in the ink receiving layer of the support, wherein the acid and the salt have a solubility in water of 20. 4 g or more in 100 g of a saturated aqueous solution at ℃.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The ink receiving layer of the support of the ink jet recording material of the present invention contains a sulfonic acid group (—SO ₃ H) and / or a salt of this acid. Examples of the acid having a sulfonic acid group of the present invention include sulfuric acid, sulfamic acid (= amidosulfuric acid), 2-aminomethyl hydrogen sulfate, methanesulfonic acid, hydroxymethanesulfonic acid, benzenesulfonic acid, ethylbenzenesulfonic acid, dodecylbenzenesulfone. Sulfonic acid of aromatic hydrocarbon such as acid, P-toluenesulfonic acid, alkylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, sulfonic acid of aliphatic hydrocarbon such as hexanesulfonic acid, perfluoroalkylsulfonic acid, 2-acrylamide-2 -Low molecular weight compounds such as methyl propane sulfonic acid (the molecular weight is generally 1000 or less), polystyrene sulfonic acid, polyallyl sulfone,
Polymer compounds such as polyamine sulfone, polycondensate of naphthalene sulfonic acid, polycondensate of melamine sulfonic acid, and (co) polymer of α-olefin sulfonic acid (the molecular weight is
Generally, 1000 to 10 million) is exemplified. Low molecular weight compounds are more preferable than high molecular weight compounds, among which, sulfuric acid,
Sulfamic acid, methanesulfonic acid, and hydroxymethanesulfonic acid are preferred because of their small molecular weight and the effect can be obtained by adding a small amount thereof, and sulfamic acid is particularly preferred.

As the salt of the sulfonic acid-containing acid of the present invention, any of an organic salt and an inorganic salt can be used.
For example, alkali metal salts (sodium salt, potassium salt,
Lithium salts, etc., including bisulfates such as KHSO ₄ and NaHSO ₄ ), alkaline earth metals (magnesium salts, calcium salts, barium salts, etc.), heavy metal salts (lead (II) salts, silver salts, etc.), amine compounds (Ammonium salts, hydroxylamine salts, hydrazine salts, guanidine salts, etc.). Particularly preferably, sodium salt, lithium salt,
Potassium salt and ammonium salt.

The reason why the acid containing a sulfonic acid group or a salt thereof improves the light fastness is not clear, but the interaction between the dye or pigment having an anionic group and the cationic polymer used as a water-proofing agent. Is presumed that the sulfonic acid group is softened by the interaction between ions. The solubility of the acid having a sulfonic acid group and the salt of the present invention in water is 4 g or more in 100 g of a saturated aqueous solution at 20 ° C. As a reason for the improvement of the light resistance of the present invention, it is assumed that the interaction between ions when the ink penetrates the recording material is caused, and therefore, a compound which easily dissociates as ions in water is more effective. It is believed that there is.

The acid containing a sulfonic acid group and salts thereof are chemically more stable than sulfurous acid, thiosulfuric acid and salts thereof, and have little effect on dyes and pigments.
It is considered preferable. For example, sulfurous acid and / or its salt may be oxidized by itself, which may cause a reaction with a dye or a pigment. The ink receiving layer of the invention preferably contains a cationic polymer from the viewpoint of water resistance. Examples of the cationic polymer include polyethyleneimine, polydimethyldiallylammonium chloride, polyvinylpyridine, polyamidoamine, dicyandiamide-formalin condensate, dicyandiamide polyalkyl-polyalkylenepolyamine condensate, polyallylamine hydrochloride, polyvinylamine homopolymer, Examples thereof include a polyvinylamine copolymer, a polyamidine, and a quaternary ammonium salt type acrylic resin. Preferably, a polyvinylamine homopolymer, a polyvinylamine copolymer, a polyamidine,
Grade ammonium salt type acrylic resin, particularly preferably polyvinylamine homopolymer, polyvinylamine copolymer and polyamidine. The average molecular weight of polyvinylamine homopolymer, polyvinylamine copolymer and polyamidine is generally about 1,000 to 3,000,000.

Further, a water-soluble polymer is generally added to the ink receiving layer of the present invention for the purpose of imparting ink absorbency. Examples of water-soluble polymers are gelatin, casein, gum arabic, sodium alginate, carboxymethylcellulose, polyvinylpyrrolidone, poly N-vinylformamide, poly N-vinylacetamide, sodium polyacrylate, starch, cation-modified starch, oxidized starch,
Examples thereof include polyvinyl alcohol and polyacrylamide, and preferred are gelatin, polyvinyl pyrrolidone, poly N-vinyl formamide, and polyvinyl alcohol. The molecular weight of the water-soluble polymer is generally 1
About 000 to 3,000,000 are used. The ratio of the cationic polymer to the water-soluble polymer in the ink receiving layer is usually cationic polymer: water-soluble polymer = 0.1: 99 to 99:
It is selected from a ratio of 0.1.

The ink receiving layer of the present invention may further comprise a synthetic rubber latex, a synthetic resin emulsion such as an ethylene vinyl acetate emulsion, or finely divided silica, clay, talc, diatomaceous earth, calcium carbonate, barium sulfate, satin white, Inorganic pigments such as titanium oxide, zinc oxide, and aluminum silicate, as well as dispersants, crosslinking agents, fluorescent dyes, pH adjusters, lubricants, surfactants, ultraviolet absorbers, surface sizing agents, anti-slip agents, and preservatives Other additives such as a defoaming agent, a viscosity modifier and a dye may be used in combination as long as the effects of the present invention are not impaired.

As the support used for the recording material for ink jet recording of the present invention, conventionally known materials such as paper, fiber, resin film and sheet can be used. As the paper, known papers such as base paper for coating of acidic paper and neutral paper, newsprint, printing and writing paper, foam paper and PPC paper can be used. As a method for allowing the ink or the salt thereof of the present invention to be contained in the ink receiving layer of the present invention (the layer that absorbs ink of the support), a coating liquid containing the acid or the salt of the present invention is used. Examples of the method include a method of coating the substrate surface and a method of immersing the substrate in a solution containing the acid or / and salt thereof of the present invention.

As a method of applying a coating liquid on the surface of a substrate, a coating liquid containing the acid or / salt of the present invention and other additives is coated on a substrate by a size press, a gate roll coater, It is common to use a blade coater or a calender. As the base material in this case, a known base material such as paper, resin film / sheet, or cloth can be used.
Paper and resin film / sheet are preferred. The thickness of the substrate is preferably about 5 to 300 microns. The coating liquid is an additive (an acid or / and / or a salt of the present invention) to the coating liquid.
And salts and other additives) and water by a suitable method. The coating liquid may contain other coating agents (for example, fluorescent dyes, pH adjusters, lubricants, surfactants, ultraviolet absorbers, surface sizing agents, anti-slip agents, preservatives, defoamers, viscosity adjusters , Dyes, etc.). For the purpose of controlling the mixing property, cohesiveness, etc. of the additive, the coating liquid is used to adjust the pH of the water and then add the additive, or
It may be produced by adjusting the pH of a mixture of the additive and water. In that case, in the coating liquid or the recording layer (ink receiving layer) obtained by drying, the sulfonic acid and / or its salt exists as a salt mixture of an acid and an alkali used for pH adjustment.

The acid having a sulfonic acid group according to the present invention and / or
And a salt thereof is usually 0.1 to 30%, preferably 1 to 2% in a coating layer (ink receiving layer) obtained by drying.
0% is added. Generally, an inorganic pigment (silica gel, alumina, etc.): water-soluble polymer (povar,
Gelatin, etc.): Cationic polymer (polyvinylamine, polyamidine, etc.): acid having a sulfonic acid group and / or its salt (sulfamic acid, etc.) = 0 to 90: 1
It is used in a weight ratio of ~ 99: 0.1 ~ 50: 0.1 ~ 30. Preferably, 0-12: 3-5: 0.5-2:
Use at 0.1-1.

After the coating liquid is applied to the substrate, it is dried by a known method to obtain a target recording material for inkjet. As a method of immersing the substrate in a solution containing the acid or / and salt thereof of the present invention, for example, the substrate is immersed in a solution having the same composition as the above-mentioned coating solution for an appropriate time and then dried. .
The concentration of the coating liquid and the immersion time are generally such that the acid having a sulfonic acid group and / or a salt thereof in the ink receiving layer on the support surface is 0.1 to 30%, preferably 1 to 20%. It is adjusted as follows. As a substrate used in this method, a resin film / sheet, fiber, or the like is used, and preferably, fiber is used.

[0017]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not particularly limited thereto. Hereinafter, "%" means% by weight. [Preparation of coating liquid] Silica gel (Finesil-X-3)
7: manufactured by Tokuyama Soda Co., Ltd.) and a 10% aqueous solution of polyvinyl alcohol, a waterproofing agent, and an acid or salt having a sulfonic acid group.
After mixing at the solid content ratio shown in Table 1, the solid content was determined using distilled water.
A 5% aqueous solution was used. [Coating conditions] N on plain paper (Xerox PPC paper)
o. After applying the coating liquid with a 20 bar coater,
It was left to dry overnight and kept in a constant temperature room at 23 ° C./65% humidity overnight. [Printing] Magenta and magenta were applied to the test paper produced by an inkjet printer (PM-750C manufactured by Epson Corporation).
Solid printing was performed for each color of cyan, yellow, and black. [Water resistance test] The printed test paper was immersed in tap water (20 ° C) for 1 minute, dried with a 100 ° C blast dryer for 5 minutes,
The ink remaining in the printed portion was visually evaluated according to the following criteria. The results are shown in Table 1. Evaluation criteria ◎: No bleeding, no color fading ○: Slight bleeding, no color bleeding Δ: Ink bleeds or partially flows.

X: The ink completely flows down. [Light fastness test] A printed test paper was prepared using Xenon W.C. O.
After irradiation with M (black panel temperature: 80 ° C.) for 120 hours, the degree of discoloration of each color was visually evaluated according to the following criteria. The results are shown in Table 1. Evaluation criteria ◎: No discoloration ○: Slight discoloration △: Discoloration x: Large discoloration

[0019]

[Table 1]

[0020]

The recording material of the present invention obtained as described above is excellent in water resistance and light resistance as compared with conventional recording materials.

Claims (7)

[Claims] An ink-jet recording material comprising an acid having a sulfonic acid group and / or a salt of the acid in an ink receiving layer of a support, wherein the acid and the salt have a solubility in water of 20 ° C. A recording material for inkjet which is 4 g or more in 100 g of an aqueous solution. 2. The ink jet recording material according to claim 1, wherein the acid is sulfamic acid. 3. An ink jet recording material according to claim 1, wherein the acid salt is potassium sulfamate, sodium sulfamate, ammonium sulfamate or lithium sulfamate. 4. The recording material for ink jet according to claim 1, wherein the ink receiving layer contains a cationic polymer. 5. The ink-jet recording material according to claim 1, wherein the ink-receiving layer contains a water-soluble polymer. 6. An ink jet according to claim 1, wherein the ink receiving layer contains an acid having a sulfonic acid group and / or a salt of the acid in an amount of 0.1 to 30% by weight. Recording material. 7. The inkjet recording material according to claim 1, wherein the support is a paper, a film, a sheet, or a fiber.