JPH0931380A - Ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a satisfactory print with an ink-jet image-forming apparatus by preventing blind spots in printing characters and lines. SOLUTION: An organosilicon compound is incorporated into an ink composition to thereby continuously prevent bubbling to eliminate the occurrence of blind spots in printing. When this composition is used to print characters, lines, or the like on a cloth, leather, etc., a print free from blind spots can be obtained without causing the base to shrink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel ink composition, which can be used for an ink-jet image forming apparatus to clearly draw not only on paper but also on objects to be drawn such as cloth, leather and paper. The present invention relates to an ink composition capable of drawing characters and letters.

[0002]

2. Description of the Related Art Conventionally, as an ink composition for an ink discharge type image forming apparatus, a water-based ink composition in which a dye or pigment is dispersed in an aqueous medium such as water or a water-soluble organic solvent, or an oil-based ink such as an organic solvent or wax is used. An oil-based ink composition in which dyes and pigments are dispersed in a medium is known.

In the ink ejection type image forming apparatus, ink is ejected from an ink jet head containing ink to form an image line. For this reason, it is necessary to inject the ink into the inkjet head, which may adversely affect the image quality, such as the occurrence of print voids in the image lines due to the generation of bubbles during the injection.

As a method for suppressing bubbles in the ink composition for an ink-jet type image forming apparatus, Japanese Patent Laid-Open No. 63-
Those containing a lower alkyl alcohol described in Japanese Patent No. 139963 are known. However, when the material to be drawn is a cloth, the surface treatment agent or dye of the cloth is dissolved and the lower alkyl alcohol has a color or a texture of the cloth. It may have an adverse effect such as damage. Further, the lower alkyl alcohol has a strong effect of eliminating the bubbles already generated, but has a small ability to suppress the generation of bubbles continuously. In addition, it is liable to evaporate and the storage stability is poor. In addition, alcohol may diffuse into the environment and give off odor.

[0005]

As described above, when a lower alkyl alcohol is contained for the purpose of suppressing the generation of bubbles in the ink composition for an ink discharge type image forming apparatus, an object to be drawn is When the cloth is used, it may adversely affect the cloth, such as bleeding of the surface treatment agent or dye of the cloth. Further, it is difficult to continuously and strongly suppress the generation of bubbles. In addition, since it easily evaporates, the concentration in the ink composition is lowered, and the effect of suppressing bubbles is reduced, resulting in poor storage stability. Further, odor may be generated due to evaporation and diffusion of gas. Therefore, the present invention provides an ink composition for an ink-jet image forming apparatus, in which a content for suppressing air bubbles strongly suppresses the generation of air bubbles continuously, does not adversely affect the cloth, and has good storability. The purpose is to do.

[0006]

In order to achieve this object, the ink composition according to claim 1 of the present invention has a constitution containing an organic silicon compound, and by containing the organic silicon compound, bubbles are continuously generated. Is suppressed.

Further, in the ink composition according to the second aspect, even if the ink composition containing the organosilicon compound is adhered to a cloth or leather by an air jet type marking device to draw a predetermined pattern, The leather and leather are in their original condition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.

The ink composition of the present embodiment contains an organic silicon compound to prevent bubbles from being generated, thereby preventing printing defects of an image line and obtaining a good image. .

The organosilicon compound of the present invention includes compounds represented by the following general formula.

[0011]

Embedded image

These organosilicon compounds continuously and strongly suppress the generation of bubbles. In addition, it does not evaporate and does not generate odor. In addition, since the concentration does not decrease even after long-term storage, the storage stability is excellent. Further, since the reactivity is extremely small, even when the object to be drawn is a cloth, there is no problem that the dye and the surface treatment agent are dissolved and the color and texture are impaired.

The organosilicon compound of the present invention is, in addition to the above-mentioned silicone oil, a silicone oil compound obtained by adding fine powder of silicon oxide or an additive to silicone oil, and a self-improving dispersibility in water. It also includes those which have been subjected to various kinds of treatments such as emulsification compounds, emulsions dispersed in water using an emulsifier, and solutions dissolved in organic solvents such as industrial gasoline and toluene. Further, in order to improve the dispersibility in a solvent, a mixture of cellosolves such as butyl cellosolve or polyether and the above-mentioned organic silicon compound can be used. They are,
Silicone oil compounds have excellent quick-acting and long-lasting control of air bubbles, and self-emulsifying compounds and emulsions are easy to apply to water systems.

Further, as the composition of the ink composition for an ink discharge type image forming apparatus, the composition of conventionally used ink can be applied as it is. The object of the present invention can be achieved by adding to the ink composition any one of the above-mentioned organic silicon compounds that is easily dissolved or dispersed in the solvent of the ink composition. If necessary, an organic solvent can be added in the range of 50% by weight or less when water is used as the solvent. Further, in the range of 50% by weight or less, water can be added when the organic solvent is used as the solvent. It is also possible to mix two or more kinds of organic solvents at an arbitrary ratio.

Examples of the organic solvent include alkyl alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, sec-butyl alcohol and t-butyl alcohol; amides such as dimethylformamide and dimethylacetamide. Ketones or ketone alcohols such as acetone and diacetone alcohol; tetrahydrofuran,
Ethers such as dioxane; polyethylene glycol;
Polyalkylene glycols such as polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1, 2,
Alkylene glycols such as 6-hexanetriol, thiodiglycol, hexylene glycol and diethylene glycol; cellosolves such as methyl cellosolve and ethyl cellosolve; polyhydric alcohols such as glycerin, ethylene glycol and diethylene glycol, diethylene glycol dimethyl (or ethyl) ether, Examples thereof include lower alkyl ethers of polyhydric alcohols such as carbitol and triethylene glycol monomethyl ether; and carbitol acetate.

In the air jet type marking device according to the second aspect of the invention, a negative pressure is generated by a flow of air inserted into an ink jet head containing ink described in JP-A-4-91207.
An example is one in which a predetermined pattern is drawn by ejecting ink and moving an object to be drawn, such as cloth, leather, or paper, and an inkjet head relative to each other.

An example of the ink composition for the air jet type marking device is, for example, JP-A-4-2390.
The water-soluble white powder described in JP-A No. 69 is finely dispersed in a hydrophilic organic solvent having a small dissolving power with respect to the powder, and a white pigment for increasing the white hiding power is added. This ink composition is an ink capable of erasing the lines drawn by washing with water, but the organosilicon compound of the present invention has a great effect of suppressing bubbles, and an extremely small amount can be added to the ink composition. Since air bubbles are suppressed,
Only a small amount needs to be added. Therefore, the erasability by washing with water is not lost.

The content of the organosilicon compound of the present invention in the ink composition needs to be sufficient to suppress air bubbles, and may be appropriately included depending on the ability of the organosilicon compound used. Good, but generally desirable 0.0
It is necessary to contain 1 wtppm or more, more desirably 1 wtppm or more, and further desirably 100 wtppm or more.

An embodiment based on the above contents will be described below.

(Example 1) The components of Examples of the ink for an ink jet printer are: carbon black (# 960, manufactured by Mitsubishi Chemical Co.) 5 parts by weight Dispersant Disperbyk (manufactured by BYK-Chemie) 5 parts by weight Polyvinyl alcohol (electrochemical) Kogyo Co., Ltd. B03) 1 part by weight Glycerin 10 parts by weight Defoamer (SN Deformer 381 by San Nopco Ltd.) 0.3 parts by weight Pure water 79 parts by weight.

First, glycerin in water and a dispersant Dispe
dissolve rbyk, polyvinyl alcohol, antifoaming agent,
After that, carbon black was added and sufficiently stirred to obtain a homogeneous dispersion liquid. No bubbles were observed in this dispersion when it was injected into an inkjet head. Also,
Compared to the case where no defoaming agent was added, no change in viscosity was observed. In addition, when this dispersion was used as an ink for a commercially available inkjet printer, characters and lines could be drawn well without any problems.

Example 2 An example of an ink composition used in an air jet type marking device is as follows: L-glutamic acid 230 parts by weight Titanium oxide (anatase type) 13 parts by weight Polyethylene glycol 280 parts by weight Ethylene glycol 300 parts by weight Defoaming Agent (SN Deformer 381 manufactured by San Nopco) 3 parts by weight.

First, a predetermined amount of butyl cellob, polyethylene glycol, L-glutamic acid, and titanium oxide were sequentially added to ethylene glycol, and sufficiently stirred to form a homogeneous dispersion liquid. When this dispersion was stored for a long period of time, titanium oxide precipitated, and it was necessary to shake to redisperse the titanium oxide, but no bubbles were observed even when shaken. When a character or figure was drawn on a dark-colored cloth with an air jet type marking device using this dispersion liquid, a white printing line with no missing print was obtained, and after about 10 minutes, the solvent penetrated into the drawing object. However, a part of it evaporated and became a clear image. When a steam iron was applied one hour after drawing, the image lines did not disappear at all, and when washed with water, the image lines disappeared completely.

(Example 3) In this example, the ink composition used in the air jet type marking device was as follows: white polymer resin particles (MBX-20 white manufactured by Sekisui Kasei Co., Ltd.) 150 parts by weight polyethylene glycol 85 parts by weight smectite (corp chemical) 15 parts by weight of hydrophilic smectite SWN manufactured by the same company 5 parts by weight of antifoaming agent (Dehydran 1620 manufactured by San Nopco) 5 parts by weight of pure water 755 parts by weight.

First, a predetermined amount of smectite is dispersed in water, then a predetermined amount of polyethylene glycol and an antifoaming agent are added and dissolved therein, and then white polymerized resin particles are added, followed by sufficient stirring to obtain a homogeneous dispersion. It was a liquid. When this dispersion was left to stand for 6 hours, the viscosity increased to a jelly, and it was left for another 3 weeks, but no change was observed. Then, when it was shaken, it returned to a liquid state, and the addition of the antifoaming agent did not adversely affect the thixotropic property. Further, no bubbles were generated, and the effect of suppressing bubbles was sufficiently maintained. When this dispersion was used to draw on a dark-colored fabric with the above-mentioned ink jet marking device in the same manner as in Example 2, a clear white line with no printing omission was drawn, and when a steam iron was applied 1 hour after drawing, the line was drawn. Never disappears. When washed with water, the streak disappeared completely.

(Comparative Example 1) A comparative example of an ink for an ink jet printer is as follows: 5 parts by weight of carbon black (manufactured by Mitsubishi Chemical Corporation # 960) Dispersant Disperbyk (manufactured by BYK-Chemie) 5 parts by weight Polyvinyl alcohol (Denki Kagaku Kogyo KK) B03) 1 part by weight Glycerin 10 parts by weight Pure water 79 parts by weight

A dispersion was obtained in the same manner as in Example 1 except that the defoaming agent was not added. When this dispersion liquid was used as an ink for a commercially available inkjet printer, when this dispersion liquid was injected into an inkjet head, bubbles were generated, and the generated bubbles caused some print defects.

Comparative Example 2 A comparative example to Example 2 is: L-glutamic acid 230 parts by weight Titanium oxide (anatase type) 13 parts by weight Polyethylene glycol 280 parts by weight Ethylene glycol 300 parts by weight.

As in Example 2, except that butyl cellosolve was not added to ethylene glycol.
A dispersion was prepared. When this dispersion was drawn on a dark-colored cloth with an air jet marking device, characters and figures were drawn.
A white image was obtained, and after about 10 minutes, the solvent penetrated into the object to be drawn, and part of it evaporated to form a clear image. It was

(Comparative Example 3) A comparative example with respect to Example 3 is as follows: White polymer resin particles (MBX-20 white manufactured by Sekisui Kasei Co., Ltd.) 150 parts by weight Polyethylene glycol 85 parts by weight Smectite (hydrophilic smectite SWN manufactured by Corp Chemical) 15 Parts by weight Pure water 755 parts by weight.

A dispersion was prepared in the same manner as in Example 3 except that the defoaming agent was not added. Further, when drawing was carried out by the air jet type marking device using this dispersion liquid, a slight print omission occurred in the image line.

As in the above-mentioned embodiment of the present invention, by containing the defoaming agent containing the organosilicon compound,
Generation of bubbles of the ink composition is suppressed, printing defects due to bubbles of image lines are prevented, and good drawing can be obtained. Further, even if the defoaming agent was added, there was no problem in the function as an ink, and it could be used in an ink jet printer or an air jet type marking device. Further, it rarely emits an offensive odor peculiar to ink.

According to the above-mentioned ink of the present invention, the ink composition contains an organic silicon compound, so that the generation of bubbles is suppressed, and the generation of bubbles does not cause a printing defect of an image line and a good image is obtained. Is obtained. Also in this case, an unusual odor peculiar to the ink is rarely emitted.

Further, the ink composition of the present invention is well adhered to cloth, leather, etc. by an air jet type marking device, that is, when characters, lines and the like are drawn on the cloth, leather etc., the cloth, leather etc. Without causing shrinkage, etc.
It is possible to reliably draw characters, lines, etc. without missing print.

[0035]

As is clear from the above description,
In the ink composition according to the first aspect of the present invention, by containing the organic silicon compound, the generation of bubbles is suppressed, and printing defects of image lines due to the generation of bubbles do not occur, and a good image is obtained.

Further, the ink composition according to claim 2 is well adhered to a cloth, a leather or the like by an air jet type marking device, that is, when a character or a drawing line is drawn, the ink composition shrinks on the cloth or the leather. It is possible to draw a character, an image line, or the like without causing printing defects, without causing any blurring of the dye on the cloth.

Claims (2)

[Claims] 1. An ink composition for an ink ejection type image forming apparatus, which contains an organic silicon compound. 2. The ink composition according to claim 1, wherein the ink composition is used in an air jet type marking device which directly ejects ink and directly draws a predetermined pattern by relative movement of a cloth and an inkjet head.