JPH10245513A - Ink-jet ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition which is suitable for use in recording on a non-absorptive surface such as that of a synthetic resin film, has good adhesiveness and drying property after printing, and also is almost free from occurrence of nozzle clogging by compounding a colorant, a solvent and a styrene-malice acid resin. SOLUTION: This composition comprises a colorant (for example, a dye), a solvent preferably an alcohol and/or an ether, more preferably propylene glycol methyl ether and/or dipropylene glycol monomethyl ether, and a styrene- malice acid resin preferably having a molecular weight of 8,000 to 15,000 preferably in an amount of 5.0 to 20wt.% relative to the total amount of an composition. Preferably, this composition further comprises a silicone resin desirably in an amount of 0.05 to 1.00wt.% relative to the total amount of an composition, the silicone resin desirably being a polysiloxane substituted with an organic group and/or having a molecular weight of 5,000 to 30,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet ink composition which can be used for printing by an ink-jet recording system such as an ink-jet printer, and particularly to a film or sheet made of synthetic resin, metal such as aluminum, glass, and water-proof. The present invention relates to an inkjet ink composition that can be suitably used for recording on non-absorbing surfaces such as paper, walls, rubber, and the like.

[0002]

2. Description of the Related Art Ink jet recording methods are mainly of a continuous type (charged type) and a drop-on-demand type.
nd) type (piezo type, etc.). The continuous jet method is a method in which ink droplets are continuously ejected and ink droplets are selected and recorded according to a recording signal, and are suitable for high-speed printing. In this method, recording is usually performed by controlling the charging of the generated ink droplets.

On the other hand, Drop-On-Demand (Drop-O
The n-Demand type is a method in which ink is ejected according to a recording signal, and is mainly divided into a pressure pulse method using a piezoelectric element or the like and a thermal jet method. In particular, a piezo type using a piezo piezoelectric element is used in industrial applications that take advantage of these advantages, because it allows printing at a large distance from an object to be printed and enables large printing.

[0004] Both the continuous type (charged type) and the drop-on-demand type are common in that ink droplets are ejected and recorded on a printing object.

Heretofore, these ink-jet ink compositions have a colorant and a solvent as main components, and a continuous jet method further contains a chargeable substance in addition thereto. In addition, if necessary, a solubilizing agent, an antifoaming agent, a wetting agent, a viscosity modifier, and the like are added.

[0006]

However, the development of the conventional ink-jet ink composition has been promoted mainly for recording on the absorbing surface of paper or the like, and films and sheets made of synthetic resin, metals such as aluminum, glass, etc. , Waterproof paper,
As a matter of fact, excellent inkjet ink compositions suitable for recording on non-absorbing surfaces such as walls and rubber have not yet been provided.

That is, films and sheets made of synthetic resin, metals such as aluminum, glass, waterproofed papers,
The ink-jet ink composition used for recording on a non-absorbing surface such as a wall and a rubber is different from a water-based ink which penetrates into an absorbing surface and is dried.Dryability and adhesion after printing are important issues. There was no satisfactory inkjet ink composition in this adhesiveness and drying property.

On the other hand, in the ink jet printing, the ink is passed through a thin orifice in a recording head.
In order to print by discharging from the nozzle as fine particles,
Some properties required for inks are even more stringent. For example, if the dissolution and dispersion of the colorant in the solvent is insufficient, or if the solvent dries too quickly during the discharging process from the nozzle, the nozzle may be clogged. Further, it is not preferable to use a toxic solvent from the viewpoint of safety. Therefore, it is desired that the solvent has good dispersibility and solubility of the colorant and can further impart slow drying property and safety.

An object of the present invention is to provide an ink-jet ink which is excellent in adhesiveness to a non-absorbing surface, has good drying properties on the non-absorbing surface, and hardly causes nozzle clogging of an ink-jet printer or the like. It is an object to provide a composition.

[0010]

As a result of intensive studies to solve the above-mentioned problems, it has been found that an ink-jet ink composition containing a styrene / maleic acid resin can solve the above-mentioned problems. The present invention is a colorant, a solvent, and styrene.
An inkjet ink composition containing a maleic acid resin.

Therefore, it can be suitably used as an ink-jet ink composition for recording on non-absorbing surfaces such as films and sheets made of synthetic resin, metals such as aluminum, glass, waterproofed papers, walls, and rubber. . The present invention is an ink-jet ink composition for non-absorbing surface recording.

Although the reason why the styrene / maleic acid resin improves the adhesiveness to the non-absorbing surface in the compounding system of the ink-jet ink composition is not clear, it is probably unclear.
It is considered that the polar group of the maleic acid resin imparts good adhesiveness to the non-absorbing surface.

On the other hand, the adhesiveness to the non-absorbing surface is an important factor in the adhesiveness between the ink droplet and the non-absorbing surface.
It is considered that the surface of the dried ink droplet is easily affected by the adhesion between the surface of the dried ink droplet and other substances in contact with the surface of the dried ink droplet. That is, if adhesiveness to the non-absorbing surface is imparted to the ink droplet, the ink droplet surface will also adhere to other substances that come into contact with the ink droplet surface. It is considered that the ink droplet component migrates upon contact or friction with the ink droplet surface relatively lowers the adhesiveness of the ink droplet to the non-absorbing surface.

Therefore, in the present invention, in addition to the styrene / maleic acid resin for improving the adhesiveness to the non-absorbing surface, a silicone resin for exhibiting a rubbing property (slip property) is further contained on the ink droplet surface. Adhesion to the non-absorbing surface is improved overall.

The present invention is an ink-jet ink composition containing a solvent, a styrene-maleic acid resin, and further containing a silicone resin.

BEST MODE FOR CARRYING OUT THE INVENTION

Incidentally, the molecular weight of the styrene / maleic acid resin is not particularly limited, but may be from 5,000 to 20.
A range of 000 is a practically preferable range, and a styrene / maleic acid resin having a molecular weight of 8,000 to 15,000 is particularly optimal. If the molecular weight of the styrene / maleic acid resin is less than these ranges, the adhesion to the non-absorbing surface will be deteriorated, and if it exceeds these ranges, the viscosity will be too high and nozzle clogging will easily occur.

The content of the styrene / maleic acid resin is not particularly limited either, but is preferably 1.0 to 30.0% by weight, and more preferably 5.0 to 30.0% by weight based on the total amount of the ink composition.
20.0% by weight is the optimal range. When the content of the styrene / maleic acid resin is less than these ranges, the adhesiveness to the non-absorbing surface is deteriorated, and when the content exceeds these ranges, clogging of the nozzle tends to occur.

The colorant is not particularly limited as long as it is soluble and dispersible in a solvent. For example, dyes such as monoazo type, metal complex salt type, disazo type, anthraquinone type, phthalocyanine type, triallylmethane type, etc., inorganic pigments such as carbon black, titanium oxide, zinc white, zinc sulfide, monoazo, disazo, phthalocyanine, quinacridone, etc. Organic pigments can be exemplified.

The content of the colorant in the ink-jet ink composition is 0.1 to 30.0% based on the total amount of the ink composition.
% By weight is preferred, and 0.5 to 20.0% by weight is the optimum blending range. When the content of the colorant is less than 0.5% by weight, the amount of the colorant is too small, and the color developability tends to decrease. In particular, when the content is less than 0.1% by weight, the color developability deteriorates. On the other hand, when the content of the colorant exceeds 20.0% by weight, the printability tends to decrease because the amount of the colorant is too large. In particular, when it exceeds 30.0% by weight, the printability deteriorates.

The solvent is not particularly limited as long as it dissolves and disperses the colorant and further dissolves the styrene / maleic acid resin. For example, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents and the like can be exemplified. Alcohols, ketones, esters,
Examples thereof include ethers, alcohol esters, ketone alcohols, ether alcohols, ketone ethers, ketone esters, and ester ethers.

However, more preferred solvents for this application include not only the solubility and dispersibility of the colorant and the solubility of the styrene / maleic acid resin, but also good drying properties on the non-absorbing surface. In the process of discharging from the nozzle, it is desirable to have a slow drying property. Acoles and ethers are most suitable as solvents which exhibit such contradictory drying properties and slow drying properties in this kind of ink composition system containing the styrene / maleic acid resin. The present invention is an inkjet ink composition containing at least one of alcohols and ethers in a solvent.

As the alcohol-based solvent, for example, methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, normal butyl alcohol, isobutyl alcohol, and tert-butyl alcohol can be used, but clogging in the discharging process from the nozzle is prevented. Therefore, an alcohol having a high boiling point and a slow drying property is preferable. As the glycol ether solvent, for example, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether acetate, Diethylene glycol monoethyl ether acetate, diethylene glycol monopropyl ether acetate,
Examples thereof include diethylene glycol monobutmethyl ether acetate.

Among alcohols and ethers, those having a solvent boiling point of 110 ° C. or more are excellent in slow drying property, and are particularly suitable for a drop-on-demand type ink jet recording system. However, if the boiling point of the solvent is too high, the drying property is improved, but the drying property on the non-absorbing surface is deteriorated. In this case, it is preferable to further adjust the solvent by mixing with a low boiling point solvent.

Recently, the use of nonpolar solvents such as benzene and xylene has been increasingly restricted from the viewpoints of toxicity and safety. It is desired to use highly safe, for example, propylene glycol methyl ether or dipropylene glycol monomethyl ether. In the present invention, even if at least one of such highly safe propylene glycol methyl ether and dipropylene glycol monomethyl ether is used as a solvent, the colorant and the styrene / maleic acid resin are well dissolved and dispersed, and furthermore It has been found that both the slow drying property in the discharging process from the nozzle and the drying property on the non-absorbing surface are good.

Thus, an ink-jet ink composition containing propylene glycol methyl ether and dipropylene glycol monomethyl ether as a solvent and containing a colorant and a styrene / maleic acid resin has excellent adhesion to a non-absorbing surface. In addition, the ink composition has good drying properties on the non-absorbing surface, is less likely to cause clogging of nozzles of an inkjet printer or the like, and has a higher safety.

Examples of the silicone resin include organically modified polysiloxanes. Specifically, for example, an organically modified polysiloxane (Kyoeisha Chemical Co., Ltd., trade name "Granol 100"), an organically modified polysiloxane (Kyoeisha Chemical Co., Ltd., trade name "Granol 115"), an organically modified polysiloxane (Kyoeisha Chemical Co., Ltd.) Made, brand name "Granol B
-1484 "), organically modified polysiloxane (Kyoeisha Chemical Co., trade name" Granol 200 "), organically modified polysiloxane (Kyoeisha Chemical Co., Ltd., trade name" Granol 40 ")
0 "), organically modified polysiloxane (Kyoeisha Chemical Co., trade name" Granol 420 "), organically modified polysiloxane (Kyoeisha Chemical Co., trade name" Granol 440 "), organically modified polysiloxane (Kyoeisha Chemical Co., Ltd., The trade name “Granol 450”) can be used. Among them, those having a high methyl group content are preferable. Specifically, organically modified polysiloxane (trade name “Granol 1” manufactured by Kyoeisha Chemical Co., Ltd.)
00 ", trade name" Granol 115 ", trade name" Granol 410 ", trade name" Granol 440 ") and the like.

As the organically modified polysiloxanes, a solution of an organically modified polysiloxane copolymer in xylene / phenyl glycol (manufactured by BYK Chemie, trade name "BYK-
306 "), an organically modified polysiloxane copolymer (trade name" BYK-307 ", manufactured by BYK Chemie), a xylene solution of an organically modified polysiloxane copolymer (trade name," BYK-310 ", manufactured by BYK Chemie) )), A butyl cellosolve solution of an organically modified polysiloxane copolymer (trade name “BYK-341”, manufactured by BYK Chemie) can also be suitably used.

The organically modified polysiloxanes referred to in the present invention are compounds having a structural formula of-(SiR ₂ O) n-, wherein R is methyl, ethyl, phenyl or the like, aralkyl group, polyether, Shows groups such as polyesters, ether / ester mixtures and the like. That is, any organically modified polysiloxane that does not have a high polarity, has a low surface tension, and can be oriented at the interface of the ink droplet surface can be applied. Among them, those in which R is a methyl group can be preferably used.

The molecular weight of the silicone resin, especially the organically modified polysiloxane, is 100 to 100,000, especially 5000
~ 30000 is preferred. When the molecular weight of the organically modified polysiloxane is less than 100, it is difficult to reduce the frictional force on the dried surface of the ink droplet, and the overall adhesiveness is reduced. When the molecular weight of the organically modified polysiloxanes exceeds 100,000, the dispersibility of the organically modified polysiloxanes in the ink composition is deteriorated, and the organically modified polysiloxanes float on the surface of the ink droplets in a non-uniform state. Absent. When the molecular weight of the organically modified polysiloxane is 5,000 to 30,000, this tendency is completely absent, and this is the most preferable molecular weight range of the organically modified polysiloxane.

Silicone resins, especially organically modified polysiloxanes, are not completely compatible with polar organic solvents such as alcohols and glycol ethers, and are fixed on non-absorbing surfaces as inks due to their specific surface activity. When it is performed, it is transferred to the ink droplet surface in a uniformly dispersed state. As a result, it does not affect the fixability between the ink droplet and the non-absorbing surface, and develops a characteristic rubbing property (slip property) with other substances on the ink droplet surface.

The silicone resin is desirably contained in an amount of 0.01 to 2.00% by weight based on the total amount of the ink. Especially 0.05 to 1.00% by weight based on the total amount of the ink
Optimally, it is contained. Silicone resins, especially organically modified polysiloxanes, are used in an amount of 0.1 to the total amount of the ink.
If the content is less than 05% by weight, it is difficult to reduce the frictional force on the ink droplet dried surface, and the overall adhesiveness is reduced. In particular, if the content is less than 0.01% by weight based on the total amount of the ink, it is difficult to reduce the frictional force on the ink droplet dried surface, and the overall adhesiveness is deteriorated. If the content of the silicone resin, especially the organically modified polysiloxanes, exceeds 1.00% by weight, especially 2.00% by weight, based on the total amount of the ink, the silicone resin, especially the organically modified polysiloxanes, in the ink composition It is not preferable because the dispersibility is deteriorated and the ink droplets become non-uniform and float on the surface, resulting in dull color.

The inkjet ink composition of the present invention may further contain, if necessary, various additives such as a chargeable substance, an oil-soluble resin, an antifoaming agent, a viscosity modifier, a leveling agent, and an anti-agglomeration agent. Can be. The ink-jet ink composition of the present invention is a synthetic resin film or sheet, metal such as aluminum, glass, waterproofed papers,
It can be used preferably for recording on non-absorbing surfaces such as walls and rubber, but can also be used for absorbing surfaces such as paper.

The ink-jet ink composition of the present invention comprises:
Although not particularly limited, for example, a styrene / maleic acid resin is dissolved in a solvent, a colorant and a silicone resin are added and blended in the solvent, and the mixture is stirred at room temperature or with heating. Obtained by filtration through a membrane filter.

[0034]

EXAMPLE A styrene / maleic acid resin was dissolved in a solvent according to the components and ratios shown in Tables 1 and 2, and a colorant and a silicone resin were added and mixed at room temperature, followed by stirring at room temperature. The ink-jet ink compositions of Examples 1 to 10 and Comparative Examples 1 to 5 were obtained by filtration with a membrane filter having a pore size of 1 μm.

[0035]

[Table 1]

[0036]

[Table 2]

In Tables 1 and 2, styrene / maleic acid resin * 1) Is manufactured by Seiko Chemical Co., Ltd., trade name "x-220" (molecular weight: 11,000 to 15000), styrene / maleic acid resin * 2) is manufactured by Arakawa Chemical Industry Co., Ltd., trade name "ALASTAR-
700 "(molecular weight: 8900), rosin ester * 3) Is manufactured by Arakawa Chemical Industry Co., Ltd., trade name "Super Ester A-10
0 ", styrene * 4) Is manufactured by Rika Hercules, trade name "Hicolastic A-75", rosin-modified maleic resin *
Five) Is manufactured by Arakawa Chemical Industry Co., Ltd.
3 ".

In Tables 1 and 2, silicone resin * 1)
Is manufactured by Kyoeisha Chemical Co., Ltd., trade name "Granol 115" (organic modified polysiloxane, molecular weight: 11000), silicone resin * 2) is manufactured by Kyoeisha Chemical Co., Ltd., trade name "Granol 400" (polyether-modified polysiloxane, molecular weight:
17500). In addition, fluorine surfactant * 3) Is a product of Fluorad FC-43 manufactured by 3M
"0" and vinyltrimethoxysilane * 4) are brand names "KBM1003" manufactured by Shin-Etsu Chemical Co., Ltd.

In Tables 1 and 2, ethanol as a solvent has a boiling point of about 78 ° C., dipropylene glycol monomethyl ether has a boiling point of 188 ° C., and propylene glycol methyl ether has a boiling point of 120 ° C.

In Tables 1 and 2, SO as a coloring agent was used.
L. BLACK29 is a product name “Varifast Black 3810” manufactured by Orient Chemical Co., Ltd.
green7 is manufactured by Fuji Dye Co., Ltd.
S GREEN 737 ". The thixotropic agent as an additive is manufactured by Kyoeisha Chemical Co., Ltd., the defoaming agent is manufactured by Big Chemie, trade name "BYK-077", and the charged substance is sodium thiocyanate.

Next, after the ink-jet ink compositions of Examples 1 to 8 and Comparative Examples 1 to 5 were made into inks, a: polypropylene, b: polyethylene, c using a piezo-type impulse jet manufactured by Union Corporation. :
Printed on vinyl chloride resin, d: aluminum plate, e: glass plate, f: waterproof paper, and evaluated for adhesion to non-absorbing surface, clogging to nozzle, and dryness on non-absorbing surface did. For comparison with a conventional inkjet ink composition, a commercially available water-based ink composition for impulse jet (for absorbing surface) (Comparative Example 6) and an oil-based ink composition (for non-absorbing surface) (Comparative Example 7) were used. And evaluated in the same manner as in each example. Example 9 and Example 1
0 was evaluated in the same manner as in Example 1 except that a continuous type jet printer manufactured by Links Inc., trade name "Links 4200 Series" was used. Tables 3 and 4 show the results.

In Tables 3 and 4, in the adhesion test, a dry cotton broad was rubbed once with a load of 5 kg applied thereto, and the state of the printed coating film was observed. ◎ indicates no change at all, ○ indicates little change, and × indicates no print coating residue.

[0043]

[Table 3]

[0044]

[Table 4]

As can be seen from Tables 3 and 4, Comparative Example 8 containing no styrene / maleic acid resin or silicone resin has poor adhesion to the non-absorbing surface. In addition, when rosin ester (Comparative Example 1), styrene (Comparative Example 2), or rosin-modified maleic resin (Comparative Example 3) other than styrene / maleic acid resin was used, the adhesion to the non-absorbing surface was poor. . Both of the conventional inkjet ink compositions of Comparative Examples 6 and 7 have poor adhesion to the non-absorbing surface.

In the case of Comparative Example 4 in which only ethanol having a low boiling point was used as a solvent, the adhesion to the non-absorbing surface was good, but the slow drying property was poor, so that the practicality as an ink-jet ink composition was poor. poor.

On the other hand, Examples 1 to 6 are all good in terms of adhesiveness and drying property and no clogging of nozzles. These Examples 1 to 6 are evaluations when applied to a piezo type ink jet, and Examples 9 and 1
As shown in FIG. 5, even when applied to a continuous type ink jet, the adhesiveness and the drying property are good, and the nozzle is not clogged. On the other hand, in the case of Comparative Example 5 similarly applied to the continuous type ink jet, since styrene which is a resin other than the styrene / maleic acid resin was used, the adhesion to the non-absorbing surface was poor as in Comparative Example 2. there were.

[0048]

As described above, since the present invention is an ink-jet ink composition containing a styrene / maleic acid resin in addition to a colorant and a solvent, it has excellent adhesiveness to a non-absorbing surface. Good dryness on the absorption surface. Therefore, it can be suitably used as an ink-jet ink composition for non-absorbing surface recording, for example, a film or sheet made of synthetic resin, metal such as aluminum, glass, waterproofed papers, walls, rubber and the like.

In addition, in the case of an ink-jet ink composition further containing a silicone resin in addition to the above, the silicone resin improves the rubbing properties of the surface of the ink droplets adhering to the non-absorbing surface, so that the ink comes into contact with the surface. The effect of reducing the frictional resistance of the styrene / maleic acid resin is combined with the adhesiveness of the styrene / maleic acid resin to the non-absorbing surface, so that the synergistic and overall adhesive strength is improved.

Even if at least one of propylene glycol methyl ether and dipropylene glycol monomethyl ether is contained as a solvent in the compounding system of the present invention, it does not impair the adhesiveness to a non-absorbing surface and the drying property. In the process of discharging from the surface, the ink exhibits slow drying properties and exhibits good printing performance on the non-absorbing surface. Moreover, unlike conventional non-polar benzene and xylene, propylene glycol methyl ether and dipropylene glycol monomethyl ether are solvents having no toxicity and excellent safety, and such solvents are used as solvent components of the inkjet ink composition. The technical significance that can be achieved is extremely large.

Claims (10)

[Claims] 1. An ink-jet ink composition containing a colorant, a solvent, and a styrene / maleic acid resin. 2. The ink-jet ink composition according to claim 1, wherein the ink-jet ink composition is for non-absorbing surface recording. 3. A styrene / maleic acid resin having a molecular weight of 8
The inkjet ink composition according to claim 1, which has a molecular weight of 000 to 15,000. 4. The ink-jet ink composition according to claim 1, wherein the content of the styrene / maleic acid resin is 5.0 to 20.0% by weight. 5. The ink-jet ink composition according to claim 1, wherein the solvent is at least one of alcohols and ethers. 6. The ink-jet ink composition according to claim 5, wherein the solvent is at least one of propylene glycol methyl ether and dipropylene glycol monomethyl ether. 7. The method according to claim 1, further comprising a silicone resin.
7. The ink-jet ink composition according to any one of claims 1 to 6. 8. The ink-jet ink composition according to claim 7, wherein the silicone resin is an organically modified polysiloxane resin. 9. The silicone resin having a molecular weight of 5,000 to 30.
The ink-jet ink composition according to claim 7, which has a molecular weight of 000. 10. The ink-jet ink composition according to claim 7, wherein the silicone resin contains 0.05 to 1.00% by weight.