JP2010018742A - Water-based inkjet ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based ink composition for a piezoelectric inkjet printer, which allows a head nozzle to be unclogged even when the head nozzle is stopped or left as it is for a fixed time during the time to perform printing by using the piezoelectric inkjet printer so that the printing can be started again and performed stably. <P>SOLUTION: The water-based ink composition for the piezoelectric inkjet printer contains a coloring pigment, water, a resin, a water-soluble organic solvent and a nozzle clogging inhibitor which is selected from the group consisting of polyoxyethylene styrenated phenylethers. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water-based ink composition for a piezo-type ink jet printer, and specifically to a water-based ink composition that can prevent nozzle clogging and stably discharge ink.

Conventionally, many water-based ink compositions for ink-jet printers containing various resins have been proposed (see, for example, Patent Document 1), and printing is performed with a piezo-type ink-jet printer using such water-based ink compositions. If the head nozzles are temporarily stopped and left for a certain period of time during printing, clogging may occur due to drying of the ink in the head nozzles, and ink droplets will not fly even if printing is started again. There was a problem that it was impossible to record on the printing surface.
JP 2007-269864 A

  The present invention has been made in order to solve the above-described problem, and the head nozzle is stopped and left for a certain period of time while printing is being performed by a piezo-type ink jet printer. An object of the present invention is to provide a water-based ink composition for a piezo-type ink jet printer that does not cause clogging of nozzles and can start printing again and stably print.

  As a result of diligent investigations to achieve the above object, the present inventors have formulated a specific nozzle clogging preventive agent in the aqueous ink composition, thereby preventing nozzle clogging in a piezo ink jet printer and stabilizing the ink. The present invention has been completed by finding that a water-based ink composition that can be ejected is obtained.

  That is, the aqueous ink composition for a piezo-type ink jet printer of the present invention contains a color pigment, water, a resin, a water-soluble organic solvent, and a nozzle clogging preventive agent. It is selected from the group consisting of oxyethylene styrenated phenyl ethers.

  By using the water-based ink composition of the present invention, clogging of the head nozzle does not occur even when the head nozzle is stopped and left for a certain period of time during printing with a piezo ink jet printer. It is possible to start printing again and print stably.

The water-based ink composition of the present invention will be specifically described below.
The water-based ink composition of the present invention contains a color pigment, water, a resin, a water-soluble organic solvent, and a nozzle clogging preventing agent, and the color pigment used in the present invention is not particularly limited, For example, Pigment Yellow 12, 13, 14, 17, 20, 24, 31, 55, 74, 83, 86, 93, 109, 110, 117, 125, 128, 129, 137, 138, 139, 147, 148, 150, 153, 154, 155, 166, 168, 180, 181, 185, Pigment Orange 16, 36, 38, 43, 51, 55, 59, 61, 64, 65, 71, Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 123, 149, 168, 177, 180, 192, 202, 206, 215, 216, 217, 220, 22 224, 226, 227, 228, 238, 240, 244, 254, pigment violet 19, 23, 29, 30, 32, 37, 40, 50, pigment blue 15, 15: 1, 15: 3, 15: 4 15: 6, 22, 30, 64, 80, pigment green 7, 36, pigment brown 23, 25, 26, pigment black 7, 26, 27, 28, carbon black, titanium oxide, iron oxide, ultramarine, yellow lead , Zinc sulfide, cobalt blue, barium sulfate, calcium carbonate and the like. The blending amount of the color pigment can be arbitrarily determined depending on the type of the color pigment to be used, but is usually 0.1 to 15% by mass, preferably 0.5 to 10% by mass of the ink composition.

  The resin used in the present invention is not particularly limited. For example, vinyl resin, acrylic resin, alkyd resin, polyester resin, polyurethane resin, silicon resin, fluororesin, epoxy resin, phenoxy resin, polyolefin resin, phenol resin, novolac resin , Rosin-modified phenolic resin, amino resin such as melamine, benzoguanamine, polyamide resin, polyester polyamide resin, cellulose diacetate, cellulose triacetate, nitrocellulose, cellulose nitrate, cellulose propionate, cellulose ester resin such as cellulose acetate butyrate, methylcellulose, Ethyl cellulose, benzyl cellulose, trimethyl cellulose, cyan ethyl cellulose, carboxymethyl cellulose, carboxyethyl cell Over scan, cellulose ether resin, such as amino cellulose, and vinyl copolymer resin and modified resins acetate. These resins may be used alone or in combination of two or more. The compounding amount of the resin (solid content) can be arbitrarily determined depending on the type of the resin to be used, but is usually 0.1 to 20% by mass, preferably 0.5 to 10% by mass of the ink composition. .

  In the water-based ink composition of the present invention, water is an essential component and further contains a water-soluble organic solvent. Specific examples of the water-soluble organic solvent used in the present invention include alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, and esters such as ethyl acetate and ethyl lactate. , Polyhydric alcohols such as ethylene glycol and diethylene glycol, glycol ethers such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monobutyl ether and diethylene glycol ethyl methyl ether, γ-butyrolactone, γ-valerolactone, γ-caprolactone , Lactone compounds such as ε-valerolactone, N-methyl-2-pyrrolidone, and mixtures thereof. The amount of the solvent composed of water and a water-soluble organic solvent is usually 20 to 99% by mass, preferably 30 to 90% by mass of the ink composition, and the amount of the water-soluble organic solvent is the water-soluble used. Although it can be arbitrarily determined depending on the type of the organic solvent, etc., it is usually 10 to 49% by mass, preferably 20 to 40% by mass of the ink composition.

  The nozzle clogging inhibitor used in the present invention is polyoxyethylene styrenated phenyl ether, specifically polyoxyethylene monostyrenated phenyl ether, polyoxyethylene distyrenated phenyl ether or polyoxyethylene tristyrenated phenyl ether. -Tell. Moreover, you may mix and use a nozzle clogging prevention agent. The nozzle clogging preventive agent preferably has a weight average molecular weight Mw in the range of 100 to 20000, more preferably in the range of 200 to 10,000. The blending amount of the nozzle clogging preventive agent can be arbitrarily determined depending on the kind of the nozzle clogging preventive agent used and the like, but is usually 0.1 to 15% by mass, preferably 0.5 to 10% by mass of the ink composition. It is. When the blending amount is less than 0.1% by mass, the effect of preventing nozzle clogging is insufficient, and when it exceeds 15% by mass, the adhesion of the ink film to the printing surface is deteriorated and the ethanol resistance is lowered. Tend to.

  The water-based ink composition of the present invention may contain a surfactant, a wetting agent, a pH adjuster, a preservative, a fungicide, a phosphorus-based antioxidant, etc. used in a normal water-based ink composition as necessary. You may contain.

  Next, a method for producing the aqueous ink composition of the present invention will be described. Although the manufacturing method of the water-based ink composition of the present invention is not particularly limited, for example, the water-based ink composition can be efficiently manufactured according to the following method. That is, first, after mixing and stirring the color pigment, resin or resin emulsion, nozzle clogging inhibitor and ion-exchanged water, the mixture is processed with a sand mill disperser to disperse the color pigment into fine particles to form an aqueous pigment dispersion. obtain. Next, a water-soluble organic solvent, ion-exchanged water and, if desired, additives are added to the obtained aqueous pigment dispersion and mixed thoroughly. The aqueous ink composition of the present invention is prepared by mixing and stirring a color pigment, a resin or resin emulsion, and ion-exchanged water, treating with a sand mill disperser to prepare an aqueous pigment dispersion, and then clogging the nozzle with the aqueous pigment dispersion. It can also be prepared by adding an inhibitor, a water-soluble organic solvent, ion-exchanged water and, if desired, an additive.

The water-based ink composition of the present invention is required to have characteristics suitable for a piezo-type ink jet printer in the same manner as a normal water-based ink composition for a piezo-type ink jet printer. It is desirable that the viscosity is 1 to 100 cP (20 ° C.), the surface tension is 2 × 10 ^{−2 to} 6 × 10 ⁻² N / m, and the specific gravity is within the range of 0.8 to 1.2.

  The water-based ink composition of the present invention is particularly suitable for printing with a large-format piezo-type inkjet printer for large format, for example, printing with a piezo-type inkjet printer for the purpose of printing on outdoor articles such as sign displays. it can.

  A printed film (ink composition) after printing by a piezo-type ink jet printer is dried at room temperature to several hundred degrees Celsius to form a dry film. The base material to be printed using the water-based ink composition of the present invention is not particularly limited as long as it does not deform or deteriorate under the condition that the printing surface (ink composition) is dried. . Examples of such a base material include base materials such as metal, glass and plastic, paper whose surface is coated with resin, transparent sheets for overhead projects, outdoor articles such as sign displays, and the like.

The present invention will be specifically described below with reference to examples and comparative examples.
Example 1
Monarch (M) 1000 (carbon black pigment / manufactured by Cabot) 10 parts by mass, Jonkrill 537 (styrene acrylic emulsion, solid content 46% / manufactured by BASF) 50 parts by mass, Neugen EA-157 (polyoxyethylene monostyrene) A mixture of 0.167 parts by mass of polyoxyethylene distyrenated phenyl ether and polyoxyethylene tristyrenated phenyl ether / Daiichi Kogyo Seiyaku Co., Ltd. and 39.833 parts by mass of ion-exchanged water. To obtain an aqueous pigment dispersion.

  With respect to 30 parts by mass of the obtained aqueous pigment dispersion, 0.4 part by mass of Surflon S-145 (perfluoroalkylethylene oxide adduct / Seimi Chemical Co., Ltd.), 10 parts by mass of triethylene glycol monobutyl ether, diethylene glycol ethyl methyl 10 parts by mass of ether and 49.6 parts by mass of ion-exchanged water were mixed to obtain a water-based ink composition.

Examples 2-10 and Comparative Examples 1-2
According to the same preparation method as in Example 1, water-based ink compositions having the compositions shown in Tables 1 and 2 were prepared using the raw materials shown in Tables 1 and 2. In addition, Emulgen A-500 is a polyoxyethylene distyrenated phenyl ether manufactured by Kao Corporation, BYK190 is a block copolymer manufactured by Big Chemie, solid content of 40%, and SOLPERSE 43000 is an acrylic dispersion manufactured by Lubrizol Corporation. Agent, solid content 50%, Superflex 126 is a polyurethane dispersion manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 30%, Elitel KA-5071S is a polyester emulsion manufactured by Unitika Co., Ltd., 30% solid content, Jonkrill 63 is a water-based acrylic resin manufactured by BASF and has a solid content of 30%.

  With respect to the aqueous ink compositions obtained in Examples 1 to 10 and Comparative Examples 1 and 2, the nozzle clogging resistance and ethanol resistance were measured by the following methods and evaluated according to the following criteria.

<Nozzle clogging resistance>
When printing with a large format piezo ink jet printer, let the head stand for 15 minutes in the middle of printing, and then start printing again, the number of nozzles that can not eject ink to a predetermined position Counted and evaluated according to the following criteria.
A: The number of nozzles that cannot be discharged to a predetermined position after being left for 15 minutes is 1/60 or less of the total number of nozzles,
○: The number of nozzles that cannot be discharged to a predetermined position after being left for 15 minutes is more than 1/60 of the total number of nozzles, and less than or equal to 2/60.
X: After leaving for 15 minutes, the number of nozzles that cannot be discharged to a predetermined position is more than 2/60 of the total number of nozzles.
The evaluation results were as shown in Tables 1 and 2.

<Ethanol resistance>
Images were printed with a large format piezo inkjet printer, rubbed with gauze soaked with 75% by weight ethanol aqueous solution 10 times, and visually evaluated according to the following criteria.
◎: no trace of scratches,
○: Level of slight scratch marks but practically no problem
×: There are traces of scratches.
The evaluation results were as shown in Tables 1 and 2.

  As is clear from the evaluation results shown in Tables 1 and 2, good evaluation results were obtained for the water-based ink compositions of Examples 1 to 10 of the present invention, and the water-based ink compositions were good.

Claims (3)

  It contains a color pigment, water, a resin, a water-soluble organic solvent, and a nozzle clogging preventing agent, and the nozzle clogging preventing agent is selected from the group consisting of polyoxyethylene styrenated phenyl ethers. A water-based ink composition for a piezo inkjet printer, characterized by   2. The aqueous ink composition according to claim 1, wherein the nozzle clogging inhibitor is polyoxyethylene monostyrenated phenyl ether, polyoxyethylene distyrenated phenyl ether or polyoxyethylene tristyrenated phenyl ether.   The aqueous ink composition according to claim 1 or 2, wherein the content of the nozzle clogging inhibitor in the total ink composition is 0.1 to 15% by mass.