JP2003292858A - Inkjet printer ink giving image excellent in light fastness and water resistance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink for an inkjet printer, the ink giving an image excellent in light fastness and water resistance when it is printed on glossy paper, coated paper, and ordinary paper. <P>SOLUTION: The ink comprising a dye having an amphiphatic nature obtained by substituting an inorganic ion of an acid dye or a basic dye with an organic ion having a hydrophilic nature, an aminoalkoxysilane, a butyral resin, a water-soluble organic solvent and the other additive(s) is used. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink for an ink jet printer which can obtain a printed image excellent in light resistance and water resistance, is easy to prepare, is inexpensive, and has excellent storage stability.

[0002]

Water-based dyes have been used as color materials for ink jet printers, but images formed on plain paper have poor water resistance and light resistance, and images formed on glossy paper and coated paper are light-resistant. Was inferior to Although many studies have been conducted to improve water resistance, JP 2000
Japanese Patent Laid-Open No. 85236 proposes a method of forming an alkaline ink absorbing layer on a recording medium support by using a reactive dye. In addition, an ink using a pigment as a coloring material has been developed, attracted attention, and put into practical use for the purpose of improving water resistance and light resistance. For example, US Pat. No. 5,085,698 proposes a method using a block copolymer as a dispersant, and US Pat. No. 5,172,133 proposes a method using a specific water-soluble resin.

However, since the water-soluble resin is easily decomposed by bacteria living in the ink, the viscosity of the ink becomes large and the ink gels to deteriorate the long-term storage stability of the ink. The flow of ink is bad and the ink cartridge may become defective. Therefore, there is a demand for an ink having excellent light resistance and water resistance of a printed image and excellent long-term storage stability.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink for a printer which is excellent in long-term storage stability and in which printed images are excellent in light resistance and water resistance. Another object of the present invention is to provide an ink which is easy and inexpensive to produce, and which produces an image excellent in light resistance and water resistance when printed on plain paper as well as glossy paper and special coated paper.

[0005]

Means for Solving the Problems As a result of repeated studies for solving the above-mentioned object, the present inventor has found that an amphiphilic compound in which an inorganic ion of an acid dye or a basic dye is replaced with an organic ion having hydrophilicity. Stability for long-term storage by stirring and mixing dyes, alkoxysilanes, film-forming resins, ion-exchanged water, water-soluble organic solvents, conductivity-imparting agents, UV absorbers, and antibacterial agents that have properties, and sterilizing them with a sterilizer It can be seen that inks with excellent properties are obtained, and that by using these inks, not only glossy paper and special coated papers, but also images printed on plain paper can have excellent light resistance and water resistance. The present invention has been completed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
Examples of the organic cation that amphiphilizes the acidic dye of the present invention include tetra-n-hexylammonium bromide, tetra-n-butylammonium borofluoride, tetra-n-butylammonium perchlorate, and cetyltrimethylammonium bromide. To be Further, the organic anion that amphiphilizes the basic dye is sodium paratoluenesulfonate,
Examples thereof include N-acyl amino acid salts and alkyl ether carboxylic acid salts.

Examples of the alkoxysilane compound include aminoalkylenetrialkoxysilane, aminoalkylenedihydroxysilane obtained by hydrolyzing aminoperfluoroalkylenetrialkoxysilane, and aminoperfluoroalkylenedihydroxysilane.
Among them, 3-aminopropyltrialkoxysilane [H ₂
NCH ₂ CH ₂ CH ₂ Si (OR) ₃ ] and 4-aminoperfluorobutyltrialkoxysilane [H ₂ NCF _{2
CF 2 CF 2 CF 2 Si (} OR) 3] are preferable. The hydrolysis of these aminotrialkoxysilanes can be carried out by mixing trialkoxysilane and water and leaving it at room temperature for several hours.

As the film forming resin, a butyral resin obtained by polymerizing polyvinyl alcohol and butyraldehyde is preferable, and a polymerization degree of 200 to 500 is preferable and 250 to 350 is particularly preferable in order to obtain good film characteristics. . Specifically, Sekisui Chemical Co., Ltd.'s S-REC BL-
1, BL-2, BL-3, and the like, but not limited to these resins.

If necessary, the ink for an ink jet printer of the present invention may contain, in addition to butyral resin, a resin soluble in other organic solvents such as acrylic resin, styrene-acrylic ester resin, silicone resin, polyester resin and the like. It can be added.

As the water-soluble organic solvent, polyhydric alcohols and alkyl ethers of polyhydric alcohols are preferable in order to prevent gelation or freezing of the ink. For example, glycerin, ethylene glycol, polyethylene glycol, polypropylene glycol, ethylene glycol methyl ether and the like can be mentioned, but it is preferable to use a mixture of two or more thereof.

As the water-soluble organic solvent, lower alcohols such as methyl alcohol, ethyl alcohol and isopropanol, acetone, methyl ethyl ketone, tetrahydrofuran and the like can be used, but the dispersion stability is improved over a long period of time. Therefore, it is desirable not to add a water-soluble organic solvent having a solubility parameter (HLB) of 11 or less. The content of the water-soluble organic solvent having an HLB of 11 to 15 is preferably 5% by weight or less with respect to the total amount of the ink, and the content of the water-soluble organic solvent having an HLB of 15 or more is 5 to 50% by weight. Is desirable.

Benzophenone-based, benzotriazole-based, cyanoacrylate-based, and salicylic acid-based UV absorbers are known, but 2,4-dihydroxybenzophenone and p-t have high solubility in organic solvents, especially ethanol. -Butylphenyl salicylate is preferred. The content of the ultraviolet absorber is 0.
1 to 0.5% by weight is desirable.

As the antibacterial agents, organic antibacterial agents, inorganic antibacterial agents and natural antibacterial agents are known, and they are one of the organic antibacterial agents having high antibacterial activity and high solubility in organic solvents, especially ethyl alcohol. Triclosan (Brand name: Irgasan DP-300), Chlorxylenol (Brand name: P
CMX) is preferred. The content of triclosan with respect to the total weight of the ink is preferably 0.03 to 100 ppm, and the content of chlorxylenol is preferably 10 to 200 ppm. The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0014]

Example 1 Preparation of black ink: 5 parts of carbon black # 44 (specific surface area: 127 m ² / g BET method, basic) manufactured by Mitsubishi Chemical Co., Ltd., butyral resin (S-REC BL-1 manufactured by Sekisui Chemical Co., Ltd.) 5 parts, 3-aminopropyltriethoxysilane 6 parts, ethylene glycol (HLV = 17.8) 1
2 parts, isopropanol (HLV = 11.6) 9 parts, glycerin 3 parts, methyl ethyl ketone 54 parts, ion-exchanged water 5 parts, pt-butylphenyl salicylate 0.1
Parts, 0.01 parts of triclosan and 350 parts of zirconia beads having a diameter of 1.0 mm are put in a 500 ml poly container and stirred with a paint conditioner for 2 hours, and then 5.0
A black ink for an inkjet printer was prepared by filtering with a μm membrane filter. The average particle size of the ink is 0.167 μm, and the viscosity is 2.82 mPa · S.
Met. This ink was injected into an empty ink cartridge BCI-21 (black) manufactured by Canon Inc. with a dropper.

Preparation of yellow ink: 2 g of auramine O hydrochloride (yellow) was dissolved in 600 ml of ion-exchanged water, and 50 g of an ethanol solution containing 1 g of sodium paratoluenesulfonate was added dropwise to this solution, and a precipitate was deposited. did. The precipitate was filtered off, washed with hexane and dried under reduced pressure at room temperature to obtain 2 g of a solid.
2 parts of this yellow dye, 2 parts of butyral resin, 6 parts of 3-aminopropyltriethoxysilane, 12 parts of ethylene glycol, 9 parts of isopropanol, 3 parts of glycerin, 62 parts of methyl ethyl ketone, 5 parts of deionized water, pt-
A yellow ink was prepared by stirring 0.1 part of butylphenyl salicylate and 0.01 part of triclosan for 15 minutes at 5000 rpm with a high-speed stirrer. This ink was injected into an empty ink cartridge BCI-21 (color) manufactured by Canon Inc. with a dropper.

Preparation of magenta and cyan inks:
Rhodamine B hydrochloride (magenta) and methylene blue hydrochloride (cyan) were used to amphiphilize the dye in the same manner as in the yellow ink to prepare magenta ink and cyan ink in the same manner. It was filled with a dropper into an empty ink cartridge (color) manufactured by K.K.

By operating an inkjet printer BjC-440j manufactured by Canon Inc., plain paper (Canon CP
-250) and a photo exclusive paper (Kodak Super Premium) were printed with full-color images, air-dried for 30 minutes, and then subjected to a water resistance test and a light resistance test. The test results are shown in Table 1.

Water resistance test: After soaking in water at 35 ° C. for 24 hours, the degree of discoloration and discoloration was judged according to the following criteria. ○ No change was observed △ Partially discolored or discolored was observed × Largely discolored or discolored light resistance test: Outdoor exposure was performed for a certain period, and the degree of discoloration or discoloration was judged according to the following criteria. ○ No change after 2 months outdoor exposure △ After 1 month outdoor exposure, discolored or discolored × Half month After outdoor exposure, discolored or discolored

Comparative Example 1 A full-color image was printed in the same manner as in Example 1 by using a conventional commercially available ink BCI-21 manufactured by Canon Inc., and a water resistance test and a light resistance test were conducted. The test results are shown in Table 1.

[0020]

[Table 1]

[0021]

INDUSTRIAL APPLICABILITY In the present invention, an amphiphilic dye in which an inorganic ion of an acid dye or a basic dye is replaced with an organic ion having hydrophilicity is used, and an aminoalkoxysilane and a butyral resin are added as a film-forming resin. By doing so, a printed image having excellent water resistance and light resistance can be obtained even on plain paper.

Claims (4)

[Claims] 1. An amphiphilic dye in which an inorganic ion of an acid dye or a basic dye is replaced with an organic ion having hydrophilicity, an alkoxysilane, a film-forming resin, ion-exchanged water,
An ink characterized in that a water-soluble organic solvent, a conductivity-imparting agent, an ultraviolet absorber, an antibacterial agent and other additives are stirred and mixed, and then sterilized. 2. The ink according to claim 1, wherein the film forming resin is a butyral resin. 3. The ink according to claim 1, wherein the alkoxysilane is aminoalkylenetrialkoxysilane or aminoperfluoroalkylenetrialkoxysilane. 4. The ink according to claim 1, wherein the conductivity-imparting agent is a water-insoluble organic conductivity-imparting agent, for example, a quaternary ammonium salt of naphtholsulfonic acid.