JPH0815808B2 - Inkjet ink composition - Google Patents

Description

The present invention relates to an inkjet ink composition containing a dispersion dye / pigment as a coloring material. More specifically, it relates to an inkjet ink composition having excellent antiseptic properties, capable of stable ejection without causing nozzle clogging or filter clogging, and capable of circulating and ejecting ink for a long period of time.

[Prior Art] With the development of color inkjet technology in recent years, it has been attempted to use it for textile printing, as disclosed in, for example, Japanese Patent Laid-Open No. 54-18975.

However, compared to ink jet for paper, when it is used for textile printing, the color looks light, and the materials and types of textiles to be printed are diverse, and ink design is far more difficult. In the case of paper, dispersion-type dyes and pigments are rarely used as coloring materials, but in the case of textile printing,
Disperse dyes and pigments such as polyester disperse dye inks, polyester / cotton blend reactive disperse dye inks, and pigment inks that can be used for all materials are often used as coloring materials.

For example, JP-A 61-31469, 61-231284, 6
There is a publication of 2-225577.

On the other hand, various inkjet methods have been devised. Among them, the so-called continuous method ejects ink from a nozzle of several tens of microns while giving vibration of several tens to several hundreds of kilohertz. This ink column breaks into droplets due to the applied vibration, and the charging electrode charges the recording pattern according to the recording pattern. The deflection electrode changes the flight direction according to the amount of charge and reaches the recording paper. A pattern is formed. Ink droplets that cannot change the flight direction and are unrelated to the formation of patterns are collected from a portion called gutter and reused. When the ink is circulated and reused, the ink rots and gives off a bad odor, which causes nozzle clogging.

As a countermeasure against this, there is a method of adding a preservative to sterilize the microorganisms mixed in the ink and reduce the growth to prevent spoilage.

[Problems to be Solved by the Invention] In the research process of dispersion-type dye-pigment inks, the present inventors added an antiseptic agent as a measure against ink rot to prevent the ink rot, but the ink viscosity, surface tension, etc. It has been found that changes in physical properties with time and the sedimentation of finely dispersed dye / pigment particles in the ink are accelerated. Further, it has been found that there is a problem that the ejection direction of the ink fluctuates, nozzle clogging and filter clogging are likely to occur, and ink cannot be circulated and ejected for a long time.

The present invention provides a dispersion-type dye-pigment ink in which a dye is hardly dissolved in a main solvent and uniformly dispersed, and has an antiseptic effect, and changes in physical properties of ink, fluctuations in ink ejection direction, nozzle clogging, filter clogging, and the like. Another object of the present invention is to provide an inkjet ink composition that does not cause a change in ink storage over time or an ink use over time.

[Means for Solving the Problem] As a result of intensive studies conducted by the present inventors on a method for solving the above problems, the above problems are largely due to the interaction between the finely dispersed particles of the dye and the preservative. Clarified. In view of this point, as a result of further studies, it is possible to provide an ink composition which has a high antiseptic effect, and which hardly changes with time during use of the ink and with time during storage. The invention was reached.

 The present invention has the following configuration.

(1) In a dispersion-type dye-pigment ink in which a dye is hardly dissolved in a main solvent and uniformly dispersed, as a preservative, one or more compounds selected from fatty acids and alkali metal salts of fatty acids, and cyclic ethers are selected. An ink composition for inkjet, which comprises one or more kinds of compounds described above as constituent materials.

(2) The inkjet ink composition according to (1), which is used as an ink for textile printing. An inkjet ink composition as an essential constituent material.

 The present invention will be described in more detail.

The dispersion-type dye-pigment ink referred to in the present invention means an ink in which a dye is hardly dissolved in a main solvent and is finely dispersed uniformly. More specifically, examples of dyes and pigments using water as a main solvent include disperse dyes, pigments, reactive disperse dyes, disperse azoic dyes, and disperse cationic dyes.

These dyes and pigments are finely dispersed using an appropriate dispersant, and then used. Any appropriate dispersant may be used, but in the case of an anionic dispersant which is generally used, the interaction with the preservative is remarkable. However, the antiseptic agent in the present invention has a surprising effect that it does not cause an interaction that makes ink characteristics inappropriate even when added to a dye / pigment ink dispersed with an anionic dispersant. further,
The amount of the dispersant used is preferably 100% by weight or less based on the dye and pigment from the viewpoints of nozzle clogging and nozzle contamination.

The dye / pigment is finely pulverized to a particle size of 5 μm or less, preferably 1 μm or less, and more preferably 0.1 to 0.5 μm by an appropriate device such as a grinding mill, a crushing mill, a roll mill, a ball mill, a pearl mill and a sand grinder.

In the present invention, it is an essential condition to use two kinds of fatty acids and alkali metal salts of fatty acids and cyclic ethers as an antiseptic, and it has been found that this combination has a synergistic effect of antiseptic action. Is.

The fatty acids and alkali metal salts of fatty acids referred to in the present invention refer to saturated fatty acids, unsaturated fatty acids, aromatic fatty acids, oxyacids and monovalent metal salts of the compounds. More specifically, propionic acid, butyric acid, isobutyric acid, sorbic acid, caprylic acid, undecylenic acid, benzoic acid, chlorobenzoic acid, iodosobenzoic acid, chlorobenzoic acid, nitrobenzoic acid, salicylic acid, dibromosalicylic acid, hydroxybenzoic acid. , Chlorobenzoic acid, lactic acid, citric acid, tartaric acid and the like, and lithium, sodium and potassium salts of the compound.

Cyclic ethers are furan ring, pyran ring, and dioxane ring derivatives, specifically, furfural,
2,5-Dimethylfuran-3-carbanilide and 5-nitrofuran and their derivatives, 5-nitro-2-furfuraaldehyde-semicarbazone, 5-nitro-2-furfuraaldehyde, 5-nitro-2-furfuraaldehyde-
Acetylhydrazone, 5-nitro-2-furfuraaldehyde-p-hydroxybenzoylhydrazone, 5-nitro-2-furfuraaldehyde-2- [2-hydroxyethyl] -semicarbazone, 5-nitro-2-furfuryl methyl ether, 5 -Nitro-2-furfuraaldehyde-semioxazone, dehydroacetic acid, sodium dehydroacetate, 2H-3,4-dihydro-6-methylbilane-5-carboxylic anilide, coumarin, coumarin derivative, metadioxane, 6-acetoxy-2,4 -Dimethyl-1,3-
Dioxane, 5-bromo-5-nitro-1,3-dioxane and the like can be mentioned.

In the present invention, one or more compounds selected from the above fatty acid salts and one or more compounds selected from cyclic ethers are used in combination as a preservative. These are all known as preservatives, but the present inventors have found that the synergistic effect is observed when they are used in combination and that the dispersibility is not impaired.

The synergistic effect of the combined use can reduce the concentration of the preservative in the ink. Needless to say, in an inkjet ink, the amount of components in the ink is closely related to the reliability of the ink, and it is desirable to reduce as much as possible a component that precipitates as a solid during drying. From this point as well, it can be seen that the present invention is excellent.

The amount of these preservatives used depends on the antiseptic effect, but the minimum effective amount varies depending on the compound or the compound used in combination. In addition, since the microorganisms in the air are always mixed by the circulation and reuse of the ink, a larger amount of preservative than the minimum growth inhibitory concentration for microorganisms is usually required. Further, when the amount of the preservative used is large, there are problems that the nozzle is clogged, the jet direction of the ink is changed, and the preservative is deposited on a gutter portion for ink recovery. In view of such a point, the amount of the preservative used is 0.01 to 5 wt%, more preferably 0.05 to 3%, and the blending ratio of fatty acid, fatty acid salt and cyclic ether is 80 to 10% and 20%, respectively. 90% is preferable.

The ink having the above composition has an excellent antiseptic effect as an inkjet ink, and does not cause aggregation of dispersed fine particles, which allows stable ejection without causing nozzle clogging, filter clogging, etc., and long-term ink circulation use. It is possible. Further, it is an excellent ink that has little change in the physical properties of the ink even after long-term storage, and has no problems such as spots, uneven dyeing, and deterioration in dyeability when dyeing a fabric.

Further, other known additives may be added as ink components to improve the ink characteristics.

For example, glycols as drying inhibitors, polymers as binders, surfactants as pH adjusting agents, pH adjusting agents, conductivity adjusting agents, ion sequestering agents for stabilizing ink, defoaming agents, etc. Is mentioned.

 Hereinafter, the present invention will be described with reference to examples.

[Examples] Example 1 CI Disperse Yellow 42 drug substance 5% Demol N (Kao Corporation, naphthalenesulfonic acid formalin condensate) 3% Ethylene glycol 30% Sodium propionate (fatty acid salt preservative) 0.5% 5- Nitro-2-furfuraaldehyde-semicarbazone (cyclic ether preservative) 0.5% Ion-exchanged water 61% Mix and stir each component with the above composition, and then use a sand grinder to prepare finely dispersed ink so that the particle size is 1 micron or less. did. Further, it was filtered with a 1-micron filter to obtain an inkjet ink.

 Next, the following test was conducted using this ink.

The results are shown in Table 1, and it can be seen that there is no problem in any of the tests and the ink is excellent.

(1) Operation test A continuous ink jet device under conditions of a nozzle diameter of 90 microns, a discharge speed of about 10 m / s, and a granulation frequency of 20 kHz is continuously operated to observe nozzle clogging and fluctuations in the ejection direction. Moreover, the permeation property of the ink was examined.

(2) Storage stability Leave the ink at 5 ℃ and 40 ℃ for 1 month and observe the ink condition.
The viscosity, surface tension and pH were measured.

(3) Antiseptic test The ink that was operated for one week with the device of (1) was observed, and the filter was observed with a microscope.

(4) Culture test Ink that was run for 1 week with the device of (1) above at 1
It was allowed to stand for a week, inoculated on a malt extract agar medium, allowed to stand at 30 ° C. for 1 week, and then observed.

(5) Dyeing test Printing was performed with the device of (1) above, and fixing and soaping suitable for the dye and pigment of the ink were performed.

 The evaluation of each test is shown in the following three stages.

Comparative Example 1 In Example 1, sodium propionate and 5-nitro-
An ink having a formulation not containing 2-furfuraaldehyde-semicarbazone was prepared and the same test as in Example 1 was performed.

The results are shown in Table 1, but it can be seen that problems such as fluctuations in the ink jetting direction, filter clogging, storage stability, and ink spoilage occur without the preservative.

Example 2 CI, Pigment Blue 17 5% Vanilex RN (Sanyo Kokusaku Pulp, lignin sulfone sun) 3% Glycerin 30% Sodium salicylate (fatty acid salt preservative) 1% Sodium dehydroacetate (cyclic ether preservative) 1% Ion exchange Water 60% After mixing and stirring each component with the above composition, a finely dispersed dispersion liquid was prepared with a sand grinder so that the particle diameter was 1 micron or less.

The above dispersion liquid 90% Primal TR934HS (produced by Rohm and Haas Co., acrylic polymer) 10% After thorough mixing and stirring, it was filtered with a 5 micron filter to obtain an inkjet ink.

The results for each test are shown in Table 1, but there was no problem with any of the items.

Comparative Example 2 In Example 2 as well, a similar ink was prepared using zinc salicylate instead of sodium salicylate. The results are shown in Table 1. Although this ink did not rot, various problems occurred in running tests, storage tests, dyeing tests, and the like.

That is, it can be seen that even with the preservatives similar to the present invention, the physical properties of the ink are significantly deteriorated, and the preservatives of the present invention are particularly excellent.

Example 3 CI Disperse Red 186 drug substance 10% Newcol B12 (Nippon Emulsifier, naphthalene ethylene glycol condensate) 4% 1,4-butanediol 30% Potassium sorbate (fatty acid salt preservative) 1% Dehydroacetic acid Soda (cyclic ether antiseptic) 1% Ion-exchanged water 54% After mixing and stirring each component with the above composition, a finely dispersed ink was prepared with a sand grinder so that the particle diameter was 1 micron or less. Further, it was filtered with a 1-micron filter to obtain an inkjet ink.

The results of each test are shown in Table 1. There was no problem with either item.

Example 4 CI Disperse Red 186 drug substance 20% Newcol B12 (manufactured by Nippon Emulsifier, naphthalene ethylene glycol condensate) 8% Ion-exchanged water 72% After mixing and stirring each component with the above composition, the particle size was measured with a sand grinder. The finely dispersed dispersion liquid was adjusted to 1 micron or less.

Dispersion liquid 50% 1,4-butanediol 30% Potassium sorbate (preservative of fatty acid salt) x% Sodium dehydroacetate (preservative of cyclic ether) y% x / y = 100/0 (ppm) x / y = 0 / 100 x / y = 50/50 Ion-exchanged water Remaining components were mixed and stirred with the above composition, and then filtered with a 1-micron filter to obtain an inkjet ink.

The growth of fungi and fungi at each concentration was examined by a culture test. The results are shown in Table 2.

It can be seen that the combined use of potassium sorbate and sodium dehydroacetate has a synergistic effect of preservation.

As can be seen from the above Examples and Comparative Examples, the ink of the composition of the present invention has an excellent antiseptic effect as an inkjet ink, and is stable without causing aggregation of dispersed fine particles, nozzle clogging, filter clogging, etc. It is possible to perform various ejections, and it is possible to circulate and use the ink for a long time. Further, it is an excellent ink that has little change in the physical properties of the ink even after long-term storage, and has no problems such as spots, uneven dyeing, and deterioration in dyeability when dyeing a fabric.

[Effects of the Invention] The ink composition of the present invention has an excellent antiseptic effect as an inkjet ink, and enables stable ejection and circulation ejection of ink for a long period of time without causing nozzle clogging or filter clogging. High quality prints can be made.

Claims (2)

[Claims] 1. A dispersion-type dye-pigment ink in which a dye is substantially dissolved in a main solvent without being dissolved, and as a preservative,
1 selected from fatty acids and alkali metal salts of fatty acids
An ink composition for ink jet, which comprises, as constituent materials, one or more kinds of compounds and one or more kinds of compounds selected from cyclic ethers. 2. The ink composition for inkjet according to claim 1, which is used as an ink for textile printing.