JPS6155171A - Ink composition for ink jet recording - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent mildewproofing and antibacterial effects and good storage stability and ejectability over a long period of time, containing water, a water-soluble dye and a specified compd. CONSTITUTION:0.05-1,000ppm of a compd. of the formula (wherein R1 is H, alkyl, aralkyl, aryl; R2, R3 are each H, halogen, alkyl, aryl, cyano, alkylsulfoxy, alkylsulfonyl), a water-soluble dye [e.g. Direct Black 17 (C.I. No.27700)], 5- 60wt% wetting agent (e.g. ethylene glycol) having a penetration ratio of 30% or above, not more than 1wt% surfactant (e.g. polyoxyalkylene alkyl ether), 0.1- 5wt% buffering agent (e.g. Na2CO3) and 0.1-5wt% chelating agent (e.g. ethylenediamine-tetraacetic acid) are dissolved in water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an ink composition for inkjet recording. More specifically, the present invention relates to an inkjet recording ink composition with improved storage stability.

[Prior Art] Conventionally, the inkjet recording method records information without bringing the recording head into contact with the recording carrier by controlling and jetting ink liquid onto the recording carrier. It has been adopted in terminal printers because it can record on paper, and has become rapidly popular in recent years.

Conventionally known inkjet recording methods include a rapid reduction in the internal volume of a container, an inkjet method that ejects by extrusion or suction with a constant pressure, or an inkjet method in which a voltage is applied between a nozzle and a counter electrode. An ink jet method in which ink is electrostatically accelerated and ejected from a nozzle, and an ink mist method in which a mist is generated by ultrasonic vibrations are known.

The ink composition used in this type of inkjet recording system or ink mist recording system must: d) have sufficient density necessary for recording; ■) not evaporate and dry in the ejection nozzle (clogging); d) (1) The recorded ink does not smudge due to water or sweat, and the printed area does not disappear; ) The composition is required to have properties such as not changing physical properties or not forming a precipitate upon storage.

In particular, it is required that the ink composition does not generate solid content during long-term storage or during recording suspension periods. That is, when solid content of ink is generated, the ejection orifice becomes clogged, causing the ejection to stop. Further, even if the ejection does not stop, solid matter adheres to the ejection orifice, which tends to adversely affect the uniformity of the droplets or the stability of the droplet flight direction. Causes of such solid content include vaporization of components in the ink composition, chemical changes in the components of the ink, and growth of mold or bacteria. For example, when the components of ink undergo a chemical change,
Not only does solid content simply occur, but the physical property values, which were adjusted within an appropriate range at the time of ink formulation, may deviate from that range.

By the way, an ink composition for inkjet recording usually has a liquid medium consisting of water or water and an organic solvent and a recording agent of dye or pigment as essential components, and various additives such as wetting agents and surfactants as necessary. , l) Prepared by adding H buffering agent, chelating agent, viscosity modifier, resistivity modifier, etc. However, when adjusting the adhesive properties of ink using these additives, it is difficult to uniquely adjust each of these adhesive properties independently. For example, antifungal and bactericidal agents, which are important components for continuous circulation ejection or long-term storage stability of ink, often create coagulation components with dyes and wetting agents, or cause an unnecessary decrease in the surface tension of the liquid. There was something to be brought about. Furthermore, the antifungal and bactericidal agents used in conventional inkjet recording ink compositions can crystallize when the ink evaporates, causing clogging, or have strong odor and toxicity, which pose health and safety problems. There were many.

[Objective of the Invention] The present invention aims to improve this point, and provides an inkjet recording material that exhibits antifungal and antibacterial effects, has long-term continuous ejection, and has good storage stability. The object of the present invention is to provide an ink composition.

[Structure of the Invention] The above object of the present invention is to provide an inkjet recording ink composition containing water, a water-soluble direct dye, and at least one compound represented by the following general formula [I] (hereinafter referred to as the compound of the present invention). achieved by things.

General formula [I] In the formula, R1 represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and R2 and R3 (respectively, a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cyam L alkyl sulfoxy group, or Represents an alkylsulfonyl group.

The present invention will be explained in more detail below.

Among the groups represented by Rt in the general formula [I], preferred are alkyl groups and aralkyl groups, and more preferred are alkyl groups.

The alkyl group represented by R1 preferably has 1 carbon atom.
-20, more preferably 1-10 carbon atoms. Examples of such alkyl groups include methyl, ethyl, propyl, and octyl groups.

The alkyl group portion of the aralkyl group represented by RL has 1 to 5 carbon atoms, more preferably 1 to 2 carbon atoms, and specific examples of the aralkyl group include benzyl group and phenethyl group.

The aryl group represented by RL is, for example, a phenyl group,
Examples include naphthyl group, and phenyl group is preferred.

Each group represented by R1 may have one substituent, and examples of the substituent include a halogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group, a nitro group, and a hydroxyl group. I can do it.

R2 and R3 each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cyan group, an alkylsulfoxy group, or an alkylsulfonyl group, and among these, preferred are a hydrogen atom, a halogen atom, an alkyl group, A cyano group, more preferably a hydrogen atom or a halogen atom.

As the alkyl group and aryl group of R2 and R3, the same ones as mentioned in RL above can be mentioned, and the alkyl sulfoxy group represented by R2 and R3 may have a substituent. The number of carbon atoms in the alkyl moiety is 7 to 6, more preferably 1 to 6.
Specific examples include a methylsulfoxy group and an ethylsulfoxy group. Furthermore,
The alkylsulfonyl group represented by R2 and R3 is preferably an alkylsulfonyl group having 1 to 6 carbon atoms in the alkyl moiety, more preferably 1 to 2 carbon atoms,
Specifically, methylsulfonyl group, ethylsulfonyl group, etc. can be mentioned.

Next, typical examples of the compound of the present invention represented by the general formula [I] are shown below, but the compound of the present invention is not limited thereto.

Exemplary Compound 1, 2-Methyl-3-isothiazolone 2. 2-n-octyl-3-isothiazolone 3, 2-benzyl-3-isothiazolone 4, 2-(3,4-dichlorophenyl)-3-isothiazolone 5, 2- Methyl-5-chloro-3-isothiazolone 6, 2-methyl-4,5-dichloro-3-isothiazolone 7, 2-methyl-4-bromo-5-chloro-isothiazolone 8, 2,4-dimethyl-3-isothiazolone 9, 2
-n-octyl-5-chloro-3-isothiazolone 10.2-methyl-5-phenyl-3-isothiazolone 11.2-ethyl-4-cyano-5-methylsulfoxy-3-isothiazolone 12.2-methyl- 5-Methylsulfonyl-3-isothiazolone These compounds are described in French Patent No. 1,555,41.
It can be synthesized with reference to No. 6, or it can be obtained by using a commercially available preservative under the trade name Kathon from Rohm and Haas.

When the compound of the present invention is added to an ink composition, it can be added directly to water, or it can be dispersed in a solvent in advance and then mixed into the ink composition. like this. As the solvent, some of the wetting agents described below, such as ethylene glycol, diethylene glycol, formamide, and dimethyl sulfoxide, can be used. Furthermore, dispersions of the compounds of the present invention are commercially available and are convenient to use.

Further, the compounds of the present invention can be used alone or in combination of two or more kinds, and an example of such a combination is the combination of Exemplary Compounds 2 and 5.

The content of the compound of the present invention is appropriately determined depending on the types of other constituent components and the required liquid physical properties, but is 0.05 to 11000 pp, based on the total weight of the ink composition.
Preferably it is 0.1 to 500 ppm.

As the water-soluble direct dye used in the present invention, a wide variety of dyes can be mentioned. A specific example is shown below,
Dyes useful in the present invention are not limited to these.

Yellow: C, 1, D 1rect Yellow 33 (C,
I, No, 29020) 44 (C, I, No,
29000) Red color: C0I, Direct Red 79 (C, 1, No.
, 29065) 81 (C,I, No, 2816
0) 83 (C, 1, No, 29225) Blue color: C, I, DirectBlue 1 (C, 1, N
o, 24410>6 (C, I , No, 22610) 15 (C, 1, No, 24400) 25 (C, I , No, 23790) 71 (C, I
, No, 34140) 8G (C, 1, No, 74
180) 98 (C, 1, No, 23155) 226 (C, I, No, 22800) Black: CJ, [)irect 31ack 17 (C11,
No, 27700) 19 (C, 1, No, 35255
) 32<C, 1, No, 35440) 51 (C, I, No, 27720) 54 In the present invention, in order to dissolve the water-soluble direct dye to some extent, further reduce the vapor pressure of the ink, and suppress evaporation. It is preferred to include a wetting agent in the 1' sink composition.

These wetting agents include aliphatic polyhydric alcohols, alkyl ethers of aliphatic polyhydric alcohols, N-alkanolamines, N-alkylamides, pyrrolidones, N-alkylimidazolidinones, and oxycarboxylic acids. Examples include intramolecular esters and cyclic ethers.

Particularly preferred wetting agents are those that have a high paper penetration rate, ie, the volume of liquid that can penetrate per unit volume of paper. The penetration rate of the wetting agent into the paper is determined by dropping a certain amount of the wetting agent onto paper of known thickness and measuring the spread area.

The wetting agent preferably has a penetration rate of 30% or more,
Particularly preferred is a content of 40% or more.

Examples of aliphatic polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, trimethylene glycol, and tetraethylene glycol; examples of alkyl ethers of aliphatic polyhydric alcohols include:
For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl, leu-ethyl, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, etc.; - N-alkanolamines include, for example, jetanolamine. , triethanolamine, ethanolamine, N-dimethylethanolamine, aminoethylethanolamine, etc.; Examples of N-alkylamides include formamide, N,N-dimethylformamide, dimethylacetamide, N-hydroxymethylformamide, N- Hydroxyethylformamide, etc.: Examples of pyrrolidones include pyrrolidones, N-vinylpyrrolidone, N-methylpyrrolidone, β-hydroxyethylpyrrolidone, N-methyl-2-pyrrolidone, etc.; N-alkylimidazolidinones, etc. ,for example,
1.3-dimethylimidazolidine, etc.; as oxycarboxylic acid intramolecular esters.

For example, valerolactone, caprolactone, γ-butyrolactone, etc.; Specific examples of the cyclic ethers include tetrahydrofuran, dioxane, etc.

If the amount of wetting agent added is less than 51% by weight, it is insufficient to prevent clogging of the nozzle tip due to ink evaporation, and if it exceeds 60% by weight, the viscosity of the ink increases. , 5 to 60 weight percent, particularly preferably 20.-60 weight percent.

Further, two or more types of wetting agents may be used in combination, and they can also be used for the purpose of adjusting physical properties such as viscosity.

The ink of the present invention is mainly composed of water, a water-soluble direct dye, and the compound of the present invention, but various additives can be optionally added as necessary. For example, surfactants can be added to adjust the surface tension that governs the wetting of the inks of the invention on the recording medium. Surfactants are not particularly limited as long as they have extremely low solubility or do not interact with dyes, but include polyoxyalkylene and its alkyl ethers, siloxane-oxyalkylene copolymers, and fluorine. Preferred are surfactants and the like.These surfactants are commercially available.

The amount of these surfactants added is generally 1% by weight or less based on the total weight of the ink, particularly 0.05 to 0.0% by weight.
A range of 5fffffi percent is desirable.

In addition, various inorganic or organic buffers can be added to the ink for the purpose of preventing pH changes mainly due to carbon dioxide absorption in the air while the ink is stored in a container or retained in a nozzle. Desirable buffering agents include, for example, carbonates such as sodium carbonate and potassium carbonate, but the appropriate amount for practical use is 0.1 to 5% by weight based on the total amount of ink. Preferably, 0.1 to 2 weight percent is appropriate.

Additionally, various chelating agents can be added for the purpose of masking the total ion and metal ions in the inks of the present invention. Typical examples include sodium gluconate, ethylenediaminetetraacetic acid 141 (EDTA), disodium salt of EDTA, trisodium salt of EDTA, sodium salt of ethylenediaminetetraacetic acid, and sodium salt of diethylenetriaminopentaacetic acid. Practically, it is appropriate to use 0.1 to 5 weight percent, preferably 0.1 to 2 weight percent, based on the total ink.

[Effects of the Invention] The ink composition of the present invention prepared in this way has many excellent properties as shown below.

In other words, no solid content, mold, etc. are generated during long-term storage or during recording suspension periods, and therefore, it is highly practical in terms of storage stability and equipment maintenance, and the uniformity of the generated droplets and droplets are improved. It also has excellent stability in the flight direction. Furthermore, the recorded images obtained have high contrast and are also excellent in water resistance, light resistance, weather resistance, abrasion resistance, and heat resistance. Alternatively, the ink is easy to prepare, low in cost, and highly versatile in that the above effects can be obtained by a basic combination of a liquid medium and a recording agent.

[Examples] The present invention will be illustrated below with reference to Examples, but the embodiments of the present invention are not limited thereto.

Margin Example 1 Composition Weight % C, I, D 1rect B 1ack32
2. ON-methylpyrrolidone 20 ethylene glycol 40 distilled water
38 The above components were mixed, heat sterilized at 60'C for 1 hour, and then filtered through a filter having a pore size of 0.6μ.

After dividing this into 100 m9 sections and adding the compound according to the present invention as shown in Table 1,
One strain of the genus S was inoculated and cultured at 25°C for 2 days.

The number of bacteria was measured by the plate dilution method. Table the results.
Shown in 1.

Margin Table 1 below: *As is clear from Table 1 of 2.4.6-hexahydro-1,3,5-trihydroxy-s-triazine described in JP-A-55-16037, the compounds of the present invention are comparatively It can be seen that it has a bactericidal effect about 1000 times more than other compounds.

Margin Example 2 Composition Weight % C, 1, Direct Blue 25 0.
O+5C, 1, Direct Blue 226
0. O15 formamide
30 ethylene glycol 30EOT
A tetrasodium salt 0.3 distilled water
39.7 The dye concentration was set to 1/100 of the normal concentration for the purpose of observation described later.

After mixing the above components and sterilizing them at 60°C for 1 hour, 0.
Filtered through a filter with a pore size of 6μ. After dividing this into 100 ml portions and adding the compound according to the present invention as shown in Table 2,
niger, penictllum Iuteur
a, 7richoderIIla T-1, and C
Aqueous dispersions of four strains of Iadosporium herbarum were inoculated in a well. After 2 weeks at 25° C., the solution was visually observed for cloudiness and floating matter, and was evaluated on a 5-point scale with 1 being no change at all and 5 being cloudiness and significant colony formation.

Table 2 From Table 2, it can be seen that samples Nos. 11 to 14 according to the present invention are resistant to solution staining and colony formation due to fungal growth.

Example 3 Composition Overlay % C, 1, Direct Black 19 3
．． 0 diethylene glycol 10.0 dimethyl sulfoxide 30.0ca H,
7(○CH2CH2)50)-120,0EDTA-tetrasodium salt 0.3 Distilled water
36.7 The above components were mixed, stirred at room temperature for 3 hours, and filtered under pressure through a filter having a pore size of 0.6μ. The compounds according to the present invention shown in Table 3 were added to this, and then degassed for 4 hours.

Table 3 The ink obtained here was adjusted to the parameters shown in Table 4 and was filled into a recording device and collected into Infusiella I described in Figures 1 to 3 of U.S. Patent No. 4,189,734.
Inkjet recording was performed on 0 types of ordinary sets.

Table 4 As a result, the printing quality was good for all sample inks, and the drying speed on paper was fast and good, within 3 seconds.

In addition, the ink was sealed in a glass container and
Even after being stored for 6 months, no precipitates were observed, and there was no change in the physical properties (viscosity, surface tension) of the liquid.

Patent applicant Roku Konishi Photo Industry Co., Ltd. Procedural Report (spontaneous) 1. Indication of the case 1982 Patent Application No. 178119 2. Name of the invention Ink composition for inkjet recording 3. Person making the amendment Related Patent applicant address: 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Name
(127) Representative Director of Konishiroku Photo Industry Co., Ltd.
Keio Benko 4, Agent 102 Address Matsuoka Kudan Building, 2-2-8 Kudanminami, Chiyoda-ku, Tokyo Phone: 263-9524 (1) The scope of the claims will be amended as shown in the attached sheet.

(2> The description of the detailed description of the invention is corrected as follows.

"Water-soluble direct dye" on page 1, line 10 of the specification is corrected to "water-soluble dye."

"Water-soluble direct dye J" on page 10, line 9 of the specification is corrected to "water-soluble dye."

The following statement is inserted between lines 17 and 18 on page 10 of the specification.

C,I, Ac1d Yellow 11 (C,I
, No, 18820>42(C,1,NOl 2
The following statement is inserted between the first and second lines of page 11 of the 2910 specification.

C,l Ac1d Red 6(C,1,No,14
680>51 (C, I, No, 45430) 52
(C,I, No, 45100)C,1,Ac1
d'Zero 130 (C, 1, No,
68215n87 (C, I, No, 4538
0) '92 (C, I, No,
45410) 94 (C, 1, No, 45440) 155 (C, I, No, 18130.) The following statement is inserted between lines 12 and 13 on page 11 of the specification.

C, 1, Ac1d Blue 9 (C, 1, No, 4
2090) 2.2 (C, [, No, 42755) 40
(C,I, No, 62125)62 (C,I
, No, 62045>93 (C, 1, No, 4
2780) 102 (C, I, No, 50320) 113
(C, I, No, 26360) 120 (C, [,
No. 26400) Details 3, page 11, line 19 and 2o
Insert the following statement between the lines.

C, T, Ac1d Black 2 (C, 1, No
, 50420>7(C,[,No, 26300>24(C,1,No, 26370) 31(C,I, No, 17580>52(C
, 1, No. 15711) # 156
- "Water-soluble direct dye" on page 11, line 20 of the specification is corrected to "water-soluble dye."

Akira [Correct "Water-soluble direct dye" on page 14, line 16 of Box 1 to "Water-soluble dye."

Above (Attachment) 2. Claims An inkjet recording ink composition comprising water, a water-soluble dye, and at least 17 compounds represented by the following general formula [I].

General formula [I] In the formula, R1 represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and R2 and R3 each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cyano group, an alkylsulfoxy group, or Represents an alkylsulfonyl group.

Claims (1)

Claims: An inkjet recording ink composition comprising water, a water-soluble direct dye, and at least one compound represented by the following general formula [I]. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1 represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and R_2 and R_3 each represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group. group, cyano group, alkylsulfoxy group or alkylsulfonyl group.