JPS6155173A - 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:10-500ppm of a compd. of the formula (wherein R1 is H, lower alkyl, hydroxymethyl; R2 is H, lower alkyl), 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. ethylenediaminetetraacetic 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 extruding or suctioning with a constant pressure, or a signal voltage is applied between a nozzle and a counter electrode. Infusiera 1, which electrostatically accelerates and ejects ink from the nozzle.
- method or an ink mist method in which a mist is generated by ultrasonic vibration is known.

The ink composition used in this type of inkjet recording method or ink mist recording method must (1) have sufficient density necessary for recording, and (2) not evaporate and dry within the ejection nozzle.
, ■) Dry immediately after ink droplets are formed on the paper (dry quickly); ■) Recorded ink does not smudge due to water or sweat, and the printed area does not disappear. , and V) characteristics such as not causing changes in physical properties or precipitation upon storage of the composition are required.

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, the solid content adheres to the ejection orifice, which tends to adversely affect the uniformity of the droplets or the stability of the flying direction of the droplets. 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, if the constituent components of ink undergo a chemical change, not only will solid content be generated, but the physical property values that were adjusted within the appropriate range for ink formulation D1 may deviate from that range. Become.

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 such as a toner or a pigment as essential components, and various additives, such as a wetting agent, as necessary. , a surfactant, a pH buffering agent, a chelating agent, a viscosity modifier, a resistivity modifier, etc. It is difficult to adjust them independently and unambiguously.For example, antifungal and bactericidal agents, which are important components for continuous circulation ejection of ink or long-term storage stability, often cause coagulation components between them and dyes and wetting agents. In addition, the anti-mold and bactericidal agents used in conventional inkjet recording ink compositions can cause crystallization when the ink evaporates, causing clogging. Many of them had strong odor and toxicity, which caused health and safety problems.

[Purpose of the Invention] The present invention focuses on improving this point, and provides a highly stable inkjet recording material that exhibits antifungal and antibacterial effects even in a very small amount, and has good long-term ejection and 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 material containing water, a water-soluble direct dye, and a compound represented by the following general formula [1] (hereinafter referred to as the compound of the present invention). This is achieved by using an ink composition.

General formula [I] R+-c-CHOH O2 In the formula, RL represents a hydrogen atom, a lower alkyl group, or a hydroxymethyl group, and RZ represents a hydrogen atom or a lower alkyl group.

The lower alkyl group represented by Rt and R2 in the general formula [] has 5 or less carbon atoms, and examples of lower alkyl groups such as 7 include methyl group, ethyl group, probyl group, and isopropyl group. etc. These may be the same or different, preferably a methyl group.

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

Exemplary compound Br ■ 1, HOCH2-C-CH20r [TS Ot Br CHs I 2, ) fOcI-I, -C, -CHO
LTN(i2 Br 3, 1(OCl-I2 CCO3 O2 4, I3r CHs ll H-C-CHOI-J) These compounds of the present invention can be synthesized with reference to the following documents.

(Literature name) (1) HenrV: Recueil d
es travauxChiIl+1ques
Rayys-3as 76.251(2)
M aas: Chen+1scl+es
Z entralb(att1899, I, 1
79 (3) E, SChmidt: 3 erichte der [) eutche
nChe+uischen G esel 1sch
aft 52,397(4) E, S chn+
idt: 1 bid, 55,317 (5) Henr
y: Qhen+1shes centralbla
tt1897, TI, 33B When the compound of the present invention is added to an inter u composition, it can be added directly to water, or it can be pre-dispersed in a solvent and then mixed into the ink composition. .

As such a solvent, some of the wetting agents described below, such as ethylene glycol, diethylene glycol, borumamide, dimethyl sulfoxide, etc., can be used.

Further, a dispersion of the compound of the invention in λ is commercially available, and it is convenient to use this.

The content of the compounds of the invention is 1i! ! Although it is determined depending on the type of constituent components and the liquid physical properties required, it is 10 to 500 pph, preferably 20 to 200 pp ni, based on the total width of the ink composition.

Water-soluble direct used in the present invention! There are various things that can be mentioned in the category 0. Specific examples are shown below, but the dyes useful in the present invention are not limited to these.

Yellow: C, 1, D 1rect Yellow 33 (C,
I, No, 29020) 44 (C, l No,
29000) Red: CJ, DirectRed 79<C,'? ,
No, 2 OG5n81 (C, I, No,
28160) 83 (C, I, No, 2922
5) Blue color: C, l, Qirect B 1ue 1 (C
,1,No,24410)6(C,I,No,
22610) 15 (C, I, No, 2440
0) 25 (C', I, No, 2379
0)71 (C0I, No, 34140)8
G(C,1,No, 74180)98(C,1,N
o, 23155) 22 & (C, 1, No, 228
00>Black: C, 1, Direct Black 17 (C, 1,
No, 27700) 19 (C, I, No, 35
255) 32 (C, I,' No, 35440
>51 (C, I, No. 27720) 54 In the present invention, the ink composition contains a wetting agent in order to dissolve the water-soluble direct dye to some extent, further lower the vapor pressure of the ink, and suppress evaporation. It is preferable to let These wetting agents include aliphatic polyhydric alcohols, alkyl ethers of aliphatic polyhydric alcohols, N-alkanolamines, N-fulkylamides, pyrrolidones,
Examples include N-alkylimidazolidinones, oxycarboxylic acid intramolecular esters, and cyclic ethers.

Particularly preferred wetting agents are those that have a high penetration rate into the paper, 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 fixed volume of the Q f-if agent onto paper of known thickness and measuring the spread area.

The wetting agent preferably has an 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, 1-diethylene glycol, trimethylene glycol, and tetraethylene glycol; examples of alkyl ethers of aliphatic polyhydric alcohols include:
For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, etc. Examples of N-alkanolamines include 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.; Examples of N-alkylimidazolidinones include 1
, 3-dimethylimidazolidine, etc.; examples of oxycarboxylic acid intramolecular esters include valerolactone, caprolactone, γ-butyrolactone, etc.; examples of cyclic ethers include, for example, tetrahydrofuran, dioxane, etc. .

If the addition of a wetting agent is less than 5%, it will not be sufficient to prevent clogging of the nozzle tip due to ink evaporation, and if it exceeds 60[1%, the viscosity of the ink will increase. , 5 to 60 weight percent is preferred, particularly 2 to 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 may be optionally added as necessary. For example, the surface tension that governs the wetting of the ink of the present invention on recording paper is vJ
Surfactants can be added to improve the stability. The surfactant is not particularly limited as long as it has extremely low solubility or does not interact with dyes, but polyoxyalkylene and its alkyl ethers, siloxane-oxyalkylene copolymers, fluorine-based Surfactants and the like are preferred. These surfactants are commercially available.

The amount of these surfactants added is generally 1 weight percent or less based on the total amount of ink, but especially 0.05 to 0.
A range of 5fffffl percent is desirable.

In addition, various kinds of buffering agents or organic buffers can be added to the ink for the purpose of preventing pH change 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 in practical terms, the appropriate amount of these additives is 0.1 to 5 percent based on the total amount of ink. and preferably 0.1 to 2 ffl mother percent.

In general, various chelating agents can be added for the purpose of masking the total and total ions in the inks of the present invention. Typical examples include sodium gluconate, ethylenediaminetetraacetic acid 11d (EDTA), disodium salt of EDTA, trisodium salt of EDTA, sodium salt of ethylenediaminetetraacetic acid, and sodium salt of diethylenetriaminopentaacetic acid. Practically speaking, it is appropriate to add 0.1 to 5% B based on the total amount of ink, and it is preferable to add B:
0.1-2% of Shiku is 3H.

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

In other words, no solid content, mold, etc. are generated during a long-term storage period or during a recording suspension period, and therefore the storage stability or M t
It is highly practical in terms of maintainability of a, and the uniformity of the generated droplets and the stability of the flying direction of the droplets are also excellent. In addition, the impressive documentary pictures have high contrast, are water resistant, light resistant,
It has excellent weather 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.

Example 1 Composition Heavy % C, I, Direct Black 32
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 mΩ units and adding the compound according to the present invention as shown in Table 1, Pseudomona
One strain of the genus S was inoculated and cultured at 37°C for 2 days.

The number of bacteria was determined by the plate dilution method. Table the results.
Not shown in 1.

;I: 2.4.6~Hexahydro-1,3,5-trihydroxy-8-1~Riazine described in Jimon Sho 55-16037 As is clear from Table 1, the compound of the present invention is different from the comparative compound. It can be seen that it has a superior bactericidal effect compared to.

Implementation (YiI2 Composition Mold Mouth % C, 1, Direct Blue 25 0,
015C,I, Direct Blue 22 [
i 0.015 formamide
30 ethylene glycol 30
EDTA tetrasodium salt 0.3 distilled water
39.7The dye concentration is
Will be described later! For the sake of caution, the normal concentration was set at 17,100.

The above ingredients were combined and sterilized at 60°C for 1 hour.
．． Filtered through a filter with a pore size of 6μ. After adding the compound according to the present invention as shown in FI L Table-2 every 100111J2, enterobacterial
tercroacae Jcinetobacter a
nitoratus.

p seudomonas aeru'gino
sa, and ) (lebsiellapneumon
An aqueous dispersion of four strains of Iae was inoculated at a constant rate.

After 2 weeks at 37°C, visually inspect the solution to see if it is cloudy.
The floating matter was observed and evaluated on a 5-level scale, with 1 being no change at all and 5 being cloudy or with significant colony formation.

Table 2 Table 2 shows 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 Word base 96 C, I, D 1rect B 1ack 19
3,0 diethylene glycol
10.0 Dimethyl sulfoxide 30.0
Cat-Lq (OCH-2, CH2) ○)
-120,0EDTA-tetrasodium salt 0
．． 3 Distilled water 36.7 The above components were mixed and stirred at room temperature for 3 hours, followed by pressure filtration through a filter having a pore size of 0.6μ.

After adding the compounds according to the present invention shown in Table 3 to this, 4
Degassing treatment was performed for a period of time.

The ink obtained here was adjusted to the parameters shown in Table 4, US Pat.
Infusiera 1 shown in the figure was filled with the recording apparatus, and inkjet recording was performed on 10 types of plain paper collected.

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.

1, put the ink in a glass container 2: (dense moon, -30'
No precipitates were observed even after storage for 6 months in C and Go''C, and there was no change in the physical properties of the liquid (viscosity, surface tension).

Patent issuer: Roku Konishi Photo Industry Co., Ltd. (Procedure, City Headquarters, Voluntary)) 1981 ii'F Application No. 178121 ・2. Name of the invention: Ink composition for inkjet recording 3. Related Tokuko'U 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 2-chome, Chiyoda-ku, Tokyo Telephone 263-9524 (1) The scope of the claims has been amended as if they had been paid in part.

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

"Water-soluble direct dye" on page 5, line 8 of entry a1 is corrected to "water-soluble dye."

"Water-soluble direct dye" on page 8, line 10 of the specification is corrected to "water-soluble dye."

The following statement is inserted between the beginning of lines 18 and 19 on page 8 of the specification.

C,], Ac1d Yellow 11 (C,I
, No, 18820)42 (C,[,No,
22910) Insert the following statement between the 2nd and 3rd lines on page 9 of the specification.

C, 1, Ac1d Red 6 (C, 1, No, 14
680>51 (C, I, No, 45430) 52
(C,], No, 45100) C, Engineering, Ac1
d Red 80 (C, 1, No, 68215>8
7 (C, [, No, 45380) 92 (C, I, No, 45410>94 (C
,1,No. 45440) 1ss (C, I, No, 18130) Ming i
! IIIB, page 9, between lines 12 and 13, write the following statement.

C,1,△cid Blue 9(C,], No,
42090>22 (C, I, No, 4275
5) 40 (C,l, No, 62125)62
(C,I, No, 62045)93 (C,1,
No, 42780) 102 (C,I, No,
50320)+13 (C,], No, 2636
0)+20 ('C, I, No, 26400)2
34 = Write the following statement between lines 10 and 20 on page 9 of the specification!
[14 people.

C, l, △cid [31ack 2 (C,
I, No, 50420) 7 (C, I,
No, 26300>24 (C, 1, No, 26
370) 31 (C, I, No, 17580) 52
(C,], No. 15711>"Water-soluble direct dye" on page 9, line 20 of the statement date is corrected to "water-soluble dye."

To clarify, ++++ a, page 12, line 16, [water-soluble direct dye] is corrected to 1, 1 water-soluble dye.

[croacac l on page 17, line 14]
Correct it to loacae J.

Above (Attachment) 2. Claims: An inkjet recording ink composition characterized by containing water, a water-soluble dye, and a compound represented by the following general formula M].

General formula [EcoR+ CCHOH O2 In the formula, R1 represents a hydrogen atom, a lower alkyl group, or a hydroxymethyl group, and R2 represents a hydrogen atom or a lower alkyl group.

Claims (1)

Claims: An inkjet recording ink composition comprising water, a water-soluble direct dye, and a compound represented by the following general formula [I]. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ In the formula, R_1 represents a hydrogen atom, a lower alkyl group, or a hydroxymethyl group, and R_2 represents a hydrogen atom or a lower alkyl group.