JP2000226545A - Ink for ink-jetting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ink-jet ink capable of being stably used for a long period without clogging and generating contaminants, when used for a nozzle of recording head, etc. SOLUTION: This ink-jet ink contains a compound of which the minimum inhibitory concentration(MIC) to Bacillus subtillis is greater than the MIC to Aspergillus niger, and a compound of which the MIC to Bacillus subtillis is smaller than the MIC to Aspergillus niger as antibacterial agents.

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, and more particularly to an ink-jet ink having improved stability during long-term use.

[0002]

2. Description of the Related Art In an ink jet recording method for recording information by ejecting a controlled amount of ink to a recording material, a recording head is not brought into contact with the recording material, so that there is no noise and high-speed recording is possible. It also has the advantage that it can be recorded on plain paper.

[0003] Inks used in such an ink jet recording method often include various dyes or pigments and water and / or a water-soluble organic solvent which dissolves or disperses them as basic components. Those to which various additives are added are known and used.

[0004] Such inks have (1) no clogging at the nozzles of the recording head, and (2) appropriate physical property values in order to satisfy the ejection characteristics (flying stability, frequency response, etc.). (3) Do not corrode the material that comes into contact with the ink. (4) Stable for long-term storage. (5) Stable re-discharge after long-term non-discharge, etc. Is required.

[0005] Further, when the ink is printed on a recording material, the following characteristics are required: (6) quick drying; (7) good printing quality; (8) storage stability as a recorded image (light fastness, Water resistance etc.) are required.

When ink is stored for a long time in an unused state,
Molds and various bacteria mixed during the production will propagate and cause the ink to spoil. In addition, when the ink container is used for a long period of time, outside air enters the ink container as the ink is consumed. At this time, molds and various kinds of bacteria are brought in at the same time, causing ink to decompose.

[0007] When molds and various bacteria grow in the ink, the nozzles are clogged, and the ink cannot be ejected normally due to a change in physical properties such as viscosity of the ink.

It is known to add various preservatives to prevent the growth of molds and various bacteria. However, if a large amount of preservative is added to provide sufficient preservative ability, problems such as the inability to obtain appropriate physical properties to satisfy the injection characteristics and the preservative itself interacting with the coloring material. was there. In addition, when a large amount of preservative is used, there is a case where there is a problem in safety such as occurrence of rash when attached to the skin.

Although many proposals have been made so far as ink jet recording inks, none of them has yet been obtained which sufficiently satisfies all of the above conditions.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a recording head that can be stably used for a long period of time without causing clogging or foreign matter in nozzles or the like. An object of the present invention is to provide an inkjet ink.

[0011]

SUMMARY OF THE INVENTION The above-mentioned objects are as follows: (1) As an antibacterial agent, the minimum inhibitory concentration (MIC) against bacteria (Bacillus subtillis) is a mold (Aspergillus ni).
ger) and a compound with a higher minimum inhibitory concentration (MIC) for bacteria (Bacillus subtillis) than a mold (Aspergillus niger)
An ink-jet ink characterized by containing a compound having a concentration lower than a minimum growth inhibitory concentration (MIC) with respect to (1st invention). (2) 1,2-benzisothiazoline as an antibacterial agent
3-one, 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, 5-chloro-2-methyl-4
-Isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-bromo-2-nitropropane-1,3-diol, 2-bromo-2-bromomethylglutaronitrile Compound and sodium 2-pyridinethiol-1-oxide, 3-iodo-2-
An ink jet ink containing a compound selected from propynylbutyl carbamate, 4-chloro-3-methylphenol, and sodium orthophenylphenol (second invention). (3) An inkjet ink comprising a compound having an isothiazoline skeleton and a compound having a phenol skeleton as antibacterial agents (third invention). (4) As an antibacterial agent, 1,2-benzisothiazoline-
An inkjet ink comprising a 3-one and 4-chloro-3-methylphenol (a fourth invention). (5) The inkjet ink according to any one of the above (1) to (4), which contains paraffin sulfonic acid. Achieved by

Hereinafter, the present invention will be described in detail. In the ink-jet ink of the first invention, as an antibacterial agent, a compound having a minimum inhibitory concentration (MIC) against bacteria (Bacillus subtillis) higher than a minimum inhibitory concentration (MIC) against mold (Aspergillus niger) (hereinafter referred to as compound A) ) And bacteria (Bacillus)
A compound having a minimum inhibitory concentration (MIC) for the subtilis) smaller than the minimum inhibitory concentration for the mold (Aspergillus niger) (hereinafter sometimes referred to as compound B).
However, as a combination of compound A and compound B, [MIC bacteria (Bacillus sub
tillis) / MIC mold (Aspergillus niger)]
Less than MIC bacteria (Bacillus subtill
is) / MIC mold (Aspergillus niger)] is more than 1.0.

In the present invention, the minimum inhibitory concentration (mini
mum inhibitory concentration (MIC) is a dilution series of an antibacterial agent, inoculating a certain amount of a test bacterium into the dilution series, and culturing the test bacterium at an optimum growth temperature for 60 hours. Refers to the concentration. Here, the optimum growth temperature is a temperature suitable for the growth of the test bacterium, and is 37 ° C. ± 1 ° C. here.

In the ink-jet ink of the present invention, the antibacterial agent is contained in an amount of 0.005% to 5% based on the total weight of the ink.
% Is preferably used. More preferably, 0.05% or more
0.5%.

In the third invention, the compound having an isothiazoline skeleton is a compound having a structure represented by the following chemical formula [1].

[0016]

Embedded image (Here, R ₁ , R ₂ , and R ₃ each represent hydrogen, an alkyl group, or a halogen atom. R ₁ and R ₂ may be bonded to each other to form a ring.)

Preferred examples of the compound having an isothiazoline skeleton are shown below, but the present invention is not limited thereto.

[0018]

Embedded image

The compound having a phenol skeleton is a compound having a structure represented by the following chemical formula [2].

[0020]

Embedded image (Here, R _{4 to} R ₈ each represent hydrogen, a linear or branched alkyl group which may be substituted, an aryl group which may be substituted, or a halogen atom.)

Preferred examples of the compound having a phenol skeleton are described below, but the present invention is not limited thereto.

[0022]

Embedded image

Embedded image

The ink-jet ink containing the antibacterial agent of the present invention preferably contains paraffin sulfonic acid. Paraffin sulfonic acid is a compound obtained by sulfonating paraffin. Paraffin is a methane-based hydrocarbon having 14 to 40 carbon atoms. As the paraffin sulfonic acid used in the present invention, any of paraffin sulfonic acids having 14 to 40 carbon atoms can be used.
20 paraffin sulfonic acid.

The counter ion of paraffin sulfonic acid may be any of alkali metal, alkaline earth metal, metal, transition metal, organic base and amine ions. Here, the counter ion refers to a cation used to neutralize paraffin sulfonic acid.

The following are examples of metals and compounds serving as counter ions, but the present invention is not limited to these counter ions.

Alkali metals: lithium, sodium, potassium Alkaline earth metals: beryllium, magnesium, calcium Other metals: zinc, aluminum Transition metals: nickel, copper, cobalt, silver, iron, titanium Organic bases: guanidines, cyclic guanidine , Amidines, cyclic amidines, piperidine, piperazine, ethylenediamine, N, N-dimethylethylenediamine, acetamidine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, dimethylammoniumamine: amine

The counter ion of the paraffin sulfonic acid of the present invention is preferably an ion from an alkali metal or an organic base. More preferably, lithium, sodium,
Paraffin sulfonic acid having potassium, amine, dimethylamine and guanidine as counter ions.

In the ink-jet ink of the present invention, the paraffin sulfonic acid is a paraffin sulfonic acid excluding the counter ion, which is 0.005 to the total weight of the ink.
% To 0.5%. More preferably,
0.02% to 0.1%.

Preferred as the ink-jet ink of the present invention is an ink-jet ink containing water, a dye or pigment, a high-boiling organic solvent and the above-mentioned compound.

Examples of the high boiling organic solvent which can be used in the ink-jet ink of the present invention include amides (eg, dimethylformamide, dimethylacetamide, etc.), ketones or keto alcohols (eg, diacetone alcohol, etc.), polyalkylenes Glycols (eg, polyethylene glycol, polypropylene glycol, etc.) and alkylene glycols having an alkylene group having 2 to 6 carbon atoms (eg, ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1, 2, 6) -Hexanetriol, thiodiglycol, hexylene glycol,
And lower alkyl ethers of glycerin and polyhydric alcohols (eg, ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether, etc.).

Among these high-boiling organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether are preferred. In the ink-jet ink of the present invention, the high-boiling organic solvent preferably accounts for 10 to 70% by weight based on the total weight of the ink.

As the dyes and pigments, direct dyes,
Acid dyes, reactive dyes, basic dyes, dyes selected from disperse dyes are used, these dyes alone, or,
A plurality of types may be used in combination. These dyes or pigments are dissolved or dispersed in a solvent that is appropriately selected and used as desired.

The following are representative coloring materials used in the present invention, but the coloring materials that can be used in the present invention are not limited to these.

<Direct Dye> CI Direct Yellow 1, 4, 8, 11, 12,
24, 26, 27, 28, 33, 39, 44, 50, 5
8, 85, 86, 100, 110, 142, 144 CI Direct Red 1, 2, 4, 9, 11, 1
3, 17, 20, 23, 24, 28, 31, 33, 3
7, 39, 44, 47, 48, 51, 62, 63, 7
5, 79, 80, 81, 83, 89, 90, 94, 9
5, 99, 220, 224, 227, 243 CI Direct Blue 1, 2, 6, 8, 15, 2
2, 25, 71, 76, 78, 80, 86, 87, 9
0, 98, 106, 108, 120, 123, 163,
165, 192, 193, 194, 195, 196, 1
99, 200, 201, 202, 203, 207, 23
6, 237 CI Direct Black 2, 3, 7, 17, 19,
22, 32, 38, 51, 56, 62, 71, 74, 7
5, 77, 105, 108, 112, 117, 154

<Acid Dye> CI Acid Yellow 2, 3, 7, 17, 19, 2
3, 25, 29, 38, 42, 49, 59, 61, 7
2,99 CI Acid Orange 56,64 CI Acid Red 1,8,14,18,26,3
2, 37, 42, 52, 57, 72, 74, 80, 8
7, 115, 119, 131, 133, 134, 14
3, 154, 186, 249, 254, 256 CI Acid Violet 11, 34, 75 CI Acid Blue 1, 7, 9, 29, 87, 12
6, 138, 171, 175, 183, 234, 23
6, 249 CI Acid Green 9, 12, 19, 27, 41 CI Acid Black 1, 2, 7, 24, 26, 4
8, 52, 58, 60, 94, 107, 109, 11
0, 119, 131, 155

<Reactive Dye> CI Reactive Yellow 1, 2, 3, 13, 1
4, 15, 17, 37, 42, 76, 95, 168, 1
75 CI Reactive Red 2, 6, 11, 21, 2
2, 23, 24, 33, 45, 111, 112, 11
4, 180, 218, 226, 228, 235 CI Reactive Blue 7, 14, 15, 18, 1
9, 21, 25, 38, 49, 72, 77, 176, 2
03, 220, 230, 235 CI Reactive Orange 5, 12, 13, 35,
95 CI Reactive Brown 7, 11, 33, 37,
46 CI Reactive Green 8, 19 CI Reactive Violet 2, 4, 6, 8, 2
1, 22, 25 CI Reactive Black 5, 8, 31, 39

<Basic dye> CI basic yellow 11, 14, 21, 32 CI basic red 1, 2, 9, 12, 13 CI basic violet 3, 7, 14 CI . Basic Blue 3, 9, 24, 25

Other dyes that can be used in the ink-jet ink of the present invention include chelate dyes and azo dyes used in so-called silver dye bleaching light-sensitive materials (for example, Ciba-Geigy Cibachrome). . Here, regarding the chelate dye, for example, the description of British Patent 1,077,484 is cited.

As for the azo dyes for silver dye bleaching photographic materials, for example, British Patent Nos. 1,039,458, 1,004,957 and 1,077,6
No. 28, U.S. Pat. No. 2,612,448 is cited. In the inkjet ink of the present invention, the dye is present in an amount of 1 to 10% by weight based on the total weight of the ink.
It is preferably used.

The pigment used in the ink-jet ink of the present invention is a white or colored powder insoluble in water, oil and the like. The disperse dye refers to a dye that is soluble in oil but insoluble or hardly soluble in water and used for dyeing in a system dispersed in water. The pigment and the disperse dye used in the inkjet ink of the present invention are used by dispersing in a solvent appropriately selected as desired.

The following are examples of typical disperse dyes, but the disperse dye used in the present invention is not limited thereto. C. I. Disperse Yellow 3, 4,
5, 7, 9, 13, 24, 30, 33, 34, 42, 4,
4, 49, 50, 51, 54, 56, 58, 60, 6
3, 64, 66, 68, 71, 74, 76, 79, 8
2, 83, 85, 86, 88, 90, 91, 93, 9
8, 99, 100, 104, 114, 116, 118,
119, 122, 124, 126, 135, 140, 1
41, 149, 160, 162, 163, 164, 16
5, 179, 180, 182, 183, 186, 19
2, 198, 199, 202, 204, 210, 21
1, 215, 216, 218, 224

C. I. Disperse Orange
1, 3, 5, 7, 11, 13, 17, 20, 21, 2
5, 29, 30, 31, 32, 33, 37, 38, 4
2, 43, 44, 45, 47, 48, 49, 50, 5,
3, 54, 55, 56, 57, 58, 59, 61, 6
6, 71, 73, 76, 78, 80, 89, 90, 9
1, 93, 96, 97, 119, 127, 130, 13
9, 142

C. I. Disperse Red 1,
4, 5, 7, 11, 12, 13, 15, 17, 27, 4
3, 44, 50, 52, 53, 54, 55, 56, 5
8, 59, 60, 65, 72, 73, 74, 75, 7
6, 78, 81, 82, 86, 88, 90, 91, 9
2, 93, 96, 103, 105, 106, 107, 1
08, 110, 111, 113, 117, 118, 12
1, 122, 126, 127, 128, 131, 13
2, 134, 135, 137, 143, 145, 14
6, 151, 152, 153, 154, 157, 15
9, 164, 167, 169, 177, 179, 18
1,183,184,185,188,189,19
0, 191, 192, 200, 201, 202, 20
3, 205, 206, 207, 210, 221, 22
4, 225, 227, 229, 239, 240, 25
7, 258, 277, 278, 279, 281, 28
8, 298, 302, 303, 310, 311, 31
2,320,324,328

C. I. Disperse Violet
1, 4, 8, 23, 26, 27, 28, 31, 33,
35, 36, 38, 40, 43, 46, 48, 50, 5
1, 52, 56, 57, 59, 61, 63, 69, 77

C. I. Disperse Green
9 C. I. Disperse Brown 1, 2, 4,
9, 13, 19

C. I. Disperse Blue
3, 7, 9, 14, 16, 19, 20, 26, 27, 3,
5, 43, 44, 54, 55, 56, 58, 60, 6
2, 64, 71, 72, 73, 75, 79, 81, 8
2,83,87,91,93,94,95,96,10
2, 106, 108, 112, 113, 115, 11
8, 120, 122, 125, 128, 130, 13
9, 141, 142, 143, 146, 148, 14
9,153,154,158,165,167,17
1,173,174,176,181,183,18
5, 186, 187, 189, 197, 198, 20
0, 201, 205, 207, 211, 214, 22
4, 225, 257, 259, 267, 268, 27
0, 284, 285, 287, 288, 291, 29
3,295,297,301,315,330,333
C. I. Disperse Black 1, 3, 1
0, 24

The pigments preferred in the present invention include carbon black pigments (CI Pigment Bla).
ck 7) C.I. I. Pigment Yellow 12, 13,
14, 16, 17, 73, 74, 75, 83, 108,
109, 110, 180, 182 C.I. I. Pigment Red 5, 7, 12, 11
2, 123, 168, 184, 202 C.I. I. Pigment Blue 1, 2, 3, 1
5: 3, 16, 22, 60 C.I. I. Vat Blue 4,60.

In addition to the above, red, green, blue,
When an intermediate color is required, the following pigments are preferably used alone or in combination. C. I. Pigment Red 209, 224, 1
77, 194 C.I. I. Pigment Orange 43 C.I. I. Vat Violet 3 C.I. I. Pigment Violet 19, 23,
37 C.I. I. Pigment Green 36, 7 C.I. I. Pigment Blue 15: 6

These pigments and disperse dyes are mixed with a dispersant and other additives necessary for various desired purposes, and used after being dispersed by a disperser. As the disperser, a conventionally known ball mill, sand mill, line mill, high-pressure homogenizer, or the like can be used. A surfactant is used as a dispersant. As these surfactants, any of cationic, anionic, amphoteric and nonionic can be used.

Examples of the cationic surfactant include aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like.

Examples of the anionic surfactant include fatty acid soap, N-acyl-N-methylglycine salt, N-acyl-
N-methyl-β-alanine salt, N-acyl glutamate, acylated peptide, alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, dialkyl sulfosuccinate, alkyl sulfo acetate, α-olefin sulfone Acid salt, N-acylmethyl taurine, sulfated oil, higher alcohol sulfate, secondary higher alcohol sulfate, alkyl ether sulfate, secondary higher alcohol ethoxy sulfate, polyoxyethylene alkyl phenyl ether sulfate, Monoglycosulfate, fatty acid alkylolamide sulfate, alkyl ether phosphate, alkyl phosphate, lignin sulfonate, formalin condensate of naphthalene sulfonate, alkyl naphthalenesul Formalin condensates of fonates and formalin condensates of special aromatic sulfonates [eg, Demol C (formalin condensate of creosote oil sulfonate)] and the like.

Examples of the amphoteric surfactant include carboxybetaine type, sulfobetaine type, aminocarboxylate, imidazolinium betaine and the like.

Examples of nonionic activators include polyoxyethylene secondary alcohol ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sterol ether, polyoxyethylene lanolin derivative polyoxyethylene polyoxypropylene alkyl ether, and polyoxyethylene glycerin fatty acid. Esters, polyoxyethylene castor oil, hydrogenated castor oil, polyoxyethylene sorbitol fatty acid ester, polyethylene glycol fatty acid ester, fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, sucrose fatty acid ester, fatty acid alkanolamide, Polyoxyethylene fatty acid amide, polyoxyethylene alkylamine, alkylamine oxa De, acetylene glycol, acetylene alcohol, block copolymers of ethylene oxide and propylene oxide, and ethylene oxide adduct of alkylphenol.

Preferred surfactants for use in the present invention include lignin sulfonates which are anionic surfactants, formalin condensates of naphthalene sulfonates, formalin condensates of alkyl naphthalene sulfonates, and special aromatic sulfones. Formalin condensates of acid salts [eg, Demol C (formalin condensates of creosote oil sulfonate)], block copolymers of ethylene oxide and propylene oxide as nonionic activators, and ethylene oxide adducts of alkylphenols. No.

A surfactant may be added to the inkjet ink of the present invention in order to accelerate the penetration of the ink droplets into the medium. The surfactant used is
There is no particular limitation as long as it does not adversely affect the ink such as storage stability, and the same surfactants as those described above as the dispersant can be used.

Further, an electric conductivity regulator can be used in the ink-jet ink of the present invention. Examples of the electric conductivity regulator include inorganic salts such as potassium chloride, ammonium chloride, sodium sulfate, sodium nitrate, and sodium chloride, and water-soluble amines such as triethanolamine.

The ink-jet ink of the present invention is optionally used for the purpose of improving ejection stability, compatibility with a print head or an ink cartridge, storage stability, image storability, and other performances. , And also a viscosity modifier,
Specific resistance adjusters, film-forming agents, ultraviolet absorbers, antioxidants, anti-fading agents, rust inhibitors and the like can also be added.

The ink jet recording system includes, for example, a continuous system and an on-demand system. The ink jet ink of the present invention can be used in either system. On-demand systems include electro-mechanical conversion systems (eg, single cavity, double cavity, bender,
Piston-type, share-mode type, shared-wall type, etc.), electro-thermal conversion method (eg, thermal inkjet type, bubble jet type, etc.), electrostatic suction type (eg, electric field control type, slit jet type, etc.), discharge method (For example, a spark jet type) can be mentioned as a specific example.

[0059]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 Ink composition sample No. 1-1 to No. 1 were configured as shown below.
-38 was created.

[0060]

<Aerial Drop Bacterial Collecting Water> Ion-exchanged water was allowed to stand in an open system for 24 hours in the room, and air dropping bacteria were collected to obtain air dropping bacterial collection water. Tables 4 to 6 show the ratio between the minimum inhibitory concentration (MIC) of the antibacterial agent against fungi and the minimum inhibitory concentration (MIC) on bacteria.

The obtained ink composition samples No. 1-1 to No. 1
1-38 was brought to a constant temperature of 38 ° C. using an incubator and 1
After continuous stirring for 70 hours, the generation of foreign matter was visually confirmed. Further, the ink composition in which generation of foreign matter was not recognized was ejected by a piezo-type ink jet tester, and occurrence of clogging was confirmed. Number of discharge nozzles = 64,
100 million dots were ejected at a nozzle diameter of 40 microns and an ejection frequency of 7 kHz, and the number of dots where clogging occurred for three or more nozzles was recorded. Also, commercially available glossy paper for inkjet printers (Konica PhotoJet Paper Photol
IKE QP (manufactured by Konica Corporation) so that the reflection density in Status T becomes 1.0, and the reflection density was examined by performing continuous irradiation for 340 hours in a xenon fade meter (10,000 lux). Tables 4 to 6 show the obtained results.

The MIC was measured by an agar plate dilution method, and a susceptibility disk medium was used as a susceptibility measurement medium.
The concentration step of the antibacterial agent should be less than 100 μg / ml and 5
0, 25, 12.5, 6.25, 3.13, 1.56,
0.78, 0.39, 0.20, 0.10, 0.05,
A two-fold serial dilution of 0.025 μg / ml was used. The bacterial solution for inoculation was grown to about 10 ⁸ / ml in an enrichment medium. Casein-
Soy mixed peptone broth was used. Inoculation method of bacteria
About 2 cm of the image was smeared with a platinum loop and cultured at 37 ° C. for 60 hours to make a judgment.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

[Table 3]

[0067]

[Table 4]

[0068]

[Table 5]

[0069]

[Table 6]

Compounds 1 to 4 in the table are the following dyes. Compound 1: Basacid Black X 34 (BASF) Compound 2: Special Black SP liquid (Bayer) Compound 3: Bayscript Black SP liquid (Bayer) Compound 4: Bayscript Black N liquid (Bayer)

The antibacterial agents 1 to 10 in the table are the following compounds. Antibacterial agent 1: 1,2-benzisothiazolin-3-one Antibacterial agent 2: 2-methyl-4,5-trimethylene-4-isothiazolin-3-one Antibacterial agent 3: 5-chloro-2-methyl-4-isothiazoline -3-one antibacterial agent 4; 2-methyl-4-isothiazolin-3-one antibacterial agent 5; 2-bromo-2-nitropropane-1,3-
Diol antibacterial agent 6; 2-bromo-2-bromomethylglutaronitrile antibacterial agent 7; 2-pyridinethiol-1-oxide sodium antibacterial agent 8; 3-iodo-2-propynylbutylcarbamate antibacterial agent 9; 4-chloro- 3-methylphenol antibacterial agent 10; sodium orthophenylphenol

From the results shown in Tables 4 to 6, it can be seen that the ink composition of the present invention has less occurrence of foreign matter and clogging than the comparative ink composition. Further, it can be seen that the ink composition of the present invention has excellent light fastness.

Example 2 A mixture having the following composition was dispersed in a sand grinder manufactured by Imex Co. using ceramic beads having a diameter of 0.5 mm at a rotation speed of 2500 rpm for 3.5 hours. 1 to No. 2-34 were created.

Compound Addition amount Coloring material (described in Tables 7 to 9) 5.0% Water / diethylene glycol = 1/4 10% Formalin condensate of creosote oil sodium sulfonate (Demol C manufactured by Kao Corporation) 10 % 2- (2ethylhexyl) sulfosoda sodium 0.05% Nonylphenol ethylene oxide 10 mol adduct 1% Antibacterial agent (described in Tables 7 to 9) Paraffin sulfonic acid described in Tables 7 to 9 Paraffin sulfonic acid described in Tables 7 to 9 Dropping in the air Bacterial collection water 50% Ion exchange water Remainder

The minimum inhibitory concentration (MIC) of the antibacterial agent against fungi and the minimum inhibitory concentration (MIC) against bacteria were measured.
The ratio of C) is shown in Tables 10 to 12. The obtained ink composition samples No. 2-1 to No. 2-34 were evaluated in the same manner as in Example 1, except that the light irradiation time with a xenon fade meter was set to 2 months. Tables 10 to 12 show the obtained results.

[0076]

[Table 7]

[0077]

[Table 8]

[0078]

[Table 9]

[0079]

[Table 10]

[0080]

[Table 11]

[0081]

[Table 12]

From the results of Tables 10 to 12, it can be seen that the ink composition of the present invention has less occurrence of foreign matter and clogging than the comparative ink composition. Further, it can be seen that the ink composition of the present invention has excellent light fastness.

[0083]

The ink-jet ink of the present invention can be stably used for a long period of time without causing clogging or generation of foreign matters in nozzles of a recording head, and has excellent reflection density.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B41J 2/01 B41M 5/00 E B41M 5/00 B41J 3/04 101Y (72) Inventor Yoko Kita Tokyo (72) Inventor Hiromi Ishihara 1 Sakura-machi, Hino-shi Konica Corporation

Claims (5)

[Claims] 1. An antibacterial agent comprising a bacterium (Bacillus subtill
is) is the minimum inhibitory concentration (MIC) for mold (Asperg
compounds with a minimum inhibitory concentration (MIC) against illus niger) and a minimum inhibitory concentration (MIC) against bacteria (Bacillus subtillis)
niger), which compound contains a compound having a smaller than the minimum inhibitory concentration (MIC). 2. Antibacterial agents include 1,2-benzisothiazolin-3-one, 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazoline- 3-one, 2-methyl-4
A compound selected from isothiazolin-3-one, 2-bromo-2-nitropropane-1,3-diol, 2-bromo-2-bromomethylglutaronitrile, sodium 2-pyridinethiol-1-oxide, -Iodo-2-propynylbutyl carbamate, 4-chloro-
An ink jet ink containing a compound selected from 3-methylphenol and sodium orthophenylphenol. 3. An ink-jet ink comprising, as antibacterial agents, a compound having an isothiazoline skeleton and a compound having a phenol skeleton. 4. An ink-jet ink comprising 1,2-benzisothiazolin-3-one and 4-chloro-3-methylphenol as antibacterial agents. 5. The ink-jet ink according to claim 1, further comprising paraffin sulfonic acid.