JP2001354889A - Ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition capable of exhibiting excellent ink- jetting stability when the ink composition is used in an inkjet recording device while keeping the safety and sufficient penetrability of the ink. SOLUTION: This ink composition comprises at least a coloring matter, a humectant, a glycol monoether as a penetrant, a 1,2-alkane diol and water, and is regulated so that the weight ratio of the glycol monoether to the 1,2-alkane diol may be within the range of (1:5)-(5:1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition having excellent ejection stability.
Specifically, the present invention relates to an ink composition used for an inkjet recording printer.

2. Description of the Related Art Ink jet recording is a method of ejecting ink as fine droplets from fine nozzles to record characters and figures on the surface of a recording medium. The inkjet recording method uses an electrostrictive element to convert an electrical signal into a mechanical signal, and intermittently discharges the ink stored in the nozzle head to record characters and symbols on the surface of the recording medium. The ink stored in the head portion is heated rapidly at a portion very close to the discharge portion to generate bubbles, and the bubbles are intermittently discharged by volume expansion due to the bubbles, thereby recording characters and symbols on the surface of the recording medium. Methods have been put to practical use.

[0003] The ink used in such ink-jet recording has good drying properties of the print, does not have bleeding of the print, can print uniformly on various surfaces of the recording medium, and has a multicolor color. Various performances such as not being mixed are required.

[0004] For this reason, in order to prevent the ink composition from drying quickly on the recording paper or to prevent mixing of inks of different colors adjacent to each other, a component which promotes penetration into the recorded matter has conventionally been incorporated into the ink composition. To be added.

[0005] For example, Japanese Patent Application Laid-Open No. 2-14260 discloses that a lower alcohol is used as a component for promoting ink permeability.

JP-A-57-55975 describes that by adding a surfactant to an ink composition, the surface tension of the ink is reduced and the permeability of the ink is improved.

[0007] JP-A-7-157698 discloses 1,2-alkanediol as a penetrant.
However, all the inks specifically disclosed in this publication contain a dye as a colorant.

[0008]

SUMMARY OF THE INVENTION The present inventors have now used an ink composition comprising a glycol monoether and a 1,2-alkanediol, and the ratio between the glycol monoether and the 1,2-alkanediol. It has been found that by setting the content within a specific range, an ink composition having excellent ejection stability can be obtained. The present invention is based on this finding. Accordingly, an object of the present invention is to provide an ink composition having excellent performance when used in an ink jet recording apparatus, particularly an ink composition having excellent ink ejection stability.

The ink composition according to the present invention comprises a colorant, a humectant, a glycol monoether,
-An ink composition comprising at least alkanediol and water, wherein the weight ratio of the glycol monoether to the 1,2-alkanediol is 1: 5 to 5: 1.
Is in the range of In the ink composition according to the present invention, the colorant is selected from a water-soluble dye or a dispersed pigment. According to one preferred embodiment of the present invention, the ink composition further comprises a nonionic surfactant.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Ink Composition The ink composition according to the present invention is used in a recording system using the ink composition. Examples of the recording method using the ink composition include an ink jet recording method, a recording method using a writing instrument such as a pen, and various other printing methods. The ink composition according to the present invention is preferably used for an ink jet recording method.

The ink composition according to the present invention comprises a combination of a 1,2-alkanediol and a glycol monoether, and a smaller amount of 1,2 than an 1,2-alkanediol. -The same permeability can be imparted to the ink by the addition amount of the alkanediol. Thereby, the amount of the 1,2-alkanediol added to the ink composition can be relatively reduced, and
-More components other than alkanediol can be added. This is advantageous from the viewpoint of designing or improving the ink. Further, the ink composition according to the present invention has excellent ejection stability. I'm not sure why,
It is expected that the wettability of the discharge nozzle of the ink composition becomes appropriate. As will be described in Examples described below, according to the ink composition of the present invention, ink does not adhere near the nozzle. It is thought that this effectively prevents the ink droplet from bending.

In the present invention, glycol monoether and 1,2-alkanediol are considered to mainly function as penetrants. In the ink composition according to the present invention, the glycol monoether and the 1,2-alkanediol are adjusted such that the ratio (weight ratio) of the glycol monoether to the 1,2-alkanediol is in the range of 1: 5 to 5: 1. And preferably the weight ratio is in the range of 1: 2 to 2: 1. Being within such a range means that while maintaining excellent ejection stability, 1,
This is advantageous from the viewpoint of reducing the amount of 2-alkanediol added.

Glycol monoether In the present invention, the glycol monoether is selected from monoether compounds of glycols such as mono and polyethylene glycol, mono and polypropylene glycol, and is represented by the following formula (i). It is preferably selected from compounds. _{R-O- [C x H 2x} -O] y -H (i) [ In the formula, R represents an alkyl group having 1 to 6 carbon atoms, a phenyl group or a benzyl group, preferably a methyl group, an ethyl group, A propyl group or a butyl group, x is 1 to 3,
It is preferably 2 or 3, and y is 1 to 8, preferably 1 to 5, more preferably 1 to 3.].

Specific examples of the glycol monoether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, and ethylene glycol. Mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether,
Ethylene glycol mono-t-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol mono-n-butyl ether, diethylene glycol mono-t
-Butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, propylene Glycol mono-n-butyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, etc. No.

Among them, in the present invention, ethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, propylene glycol monobutyl ether or dipropylene glycol monobutyl ether is 1, 1 High compatibility with 2-alkanediol is preferred.

In the present invention, the glycol monoether is contained in an amount of 0.25 to 10% by weight based on the total weight of the ink composition.
Is preferably added in the range of, more preferably, 0.1.
It is in the range of 5-5% by weight. When the content is 0.25% by weight or more, sufficient permeability can be obtained in combination with a 1,2-alkanediol, and when the content is less than 10%, the ink viscosity which can be printed together with other additives is used. This can be easily adjusted, which is advantageous.

1,2-Alkanediol In the present invention, the 1,2-alkanediol is preferably a 1,2-alkanediol having 4 to 10 carbon atoms. The 1,2-alkanediol may be added as a mixture of two or more.

In a preferred embodiment of the present invention, 1,2-
Alkanediol is 1,2-butanediol, 1,2
-Pentanediol, 1,2-hexanediol, 1,
It is selected from the group consisting of 2-heptanediol, 1,2-octanediol and mixtures thereof. More preferably, the 1,2-alkanediol has 6 carbon atoms.
-8, that is, 1,2-hexanediol, 1,2-heptanediol, or 1,2-octanediol. These are advantageous in that they have excellent permeability to the recording medium. In a further preferred aspect of the present invention, the 1,2-alkanediol is 1,2-hexanediol.

The ink composition according to the present invention comprises the above 1, 2
-Alkanediol is added in an amount of 0.1 to the total amount of the ink composition.
It is preferable that it is contained in the range of 5 to 10% by weight, and more preferable that it is contained in the range of 1 to 5% by weight. When the content is 0.5% by weight or more, sufficient permeability can be obtained, and when the content is 10% by weight or less, the viscosity of the printable ink can be easily adjusted in combination with other additives, which is advantageous. .

According to a preferred embodiment of the present invention, a combination in which the glycol monoether is glycol monobutyl ether and the 1,2-alkanediol is 1,2-hexanediol is preferred. At this time, the addition amount of the 1,2-alkanediol is preferably less than 2.5% by weight. With such an addition amount, sufficient permeability to the ink composition can be ensured and excellent. Printing stability. Here, glycol monobutyl ether means a compound in which R is a butyl group, x is 2 or 3, and y is 1 to 3 in the above formula (i), and specifically, For example, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and the like can be given.

Colorant In the present invention, a colorant can be dissolved or dispersed in an ink composition, and prints a large number of colors on a recording medium when printed by an ink jet recording apparatus. Can be done. In the ink composition according to the present invention, the colorant can be appropriately selected from dyes and pigments. Further, a dye and a pigment may be used in an appropriate combination as needed. The colorant in the present invention is preferably a colored substance such as an organic dye or pigment that can be dissolved or dispersed in an aqueous medium. These are suitable for use in inks because of their high color density per weight and vivid color.

The dye in the present invention is not particularly limited, but is usually used for ink jet recording such as direct dye, acid dye, food dye, basic dye, reactive dye, disperse dye, vat dye, and soluble vat dye. The various dyes used can be advantageously used.

The dyes usable in the present invention include:
Specifically, for example, the following can be exemplified. Specific examples of yellow dyes include C.I. I. Acid Yellow 1, 3, 11, 17, 19, 23, 25, 29, 36,
38, 40, 42, 44, 49, 59, 61, 70, 7
2, 75, 76, 78, 79, 98, 99, 110, 1,
11, 127, 131, 135, 142, 162, 16
4, 165, C.I. I. Direct Yellow 1, 8, 1
1, 12, 24, 26, 27, 33, 39, 44, 5
0, 58, 85, 86, 87, 88, 89, 98, 11
0, 132, 142, 144, C.I. I. Reactive Yellow 1, 2, 3, 4, 6, 7, 11, 12, 13, 1
4, 15, 16, 17, 18, 22, 23, 24, 2
5, 26, 27, 37, 42, C.I. I. Food yellow 3, 4 and the like.

Specific examples of magenta dyes include C.I. I. Acid Red 1, 6, 8, 9, 13, 1
4, 18, 26, 27, 32, 35, 37, 42, 5,
1, 52, 57, 75, 77, 80, 82, 85, 8
7, 88, 89, 92, 94, 97, 106, 111,
114, 115, 117, 118, 119, 129, 1
30, 131, 133, 134, 138, 143, 14
5, 154, 155, 158, 168, 180, 18
3, 184, 186, 194, 198, 209, 21
1, 215, 219, 249, 252, 254, 26
2,265,274,282,289,303,31
7, 320, 321, 322, C.I. I. Direct Red 1, 2, 4, 9, 11, 13, 17, 20, 23, 2
4, 28, 31, 33, 37, 39, 44, 46, 6
2, 63, 75, 79, 80, 81, 83, 84, 8
9, 95, 99, 113, 197, 201, 218, 2
20, 224, 225, 226, 227228, 22
9, 230, 231, C.I. I. Reactive Red 1,
2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 1
5, 16, 17, 19, 20, 21, 22, 23, 2,
4, 28, 29, 31, 32, 33, 34, 35, 3
6, 37, 38, 39, 40, 41, 42, 43, 4
5, 46, 49, 50, 58, 59, 63, 64, C.I.
I. Food Red 7, 9, 14 and the like.

Specific examples of cyan dyes include C.I.
I. Acid Blue 1, 7, 9, 15, 22, 23, 2
5, 27, 29, 40, 41, 43, 45, 54, 5
9, 60, 62, 72, 74, 78, 80, 82, 8
3, 90, 92, 93, 100, 102, 103, 10
4, 112, 113, 117, 120, 126, 12
7, 129, 130, 131, 138, 140, 14
2,143,151,154,158,161,16
6, 167, 168, 170, 171, 182, 18
3, 184, 187, 192, 199, 203, 20
4, 205, 229, 234, 236, 249, C.I.
I. Direct Blue 1, 2, 6, 15, 22, 25,
41, 71, 76, 77, 78, 80, 86, 87, 9
0, 98, 106, 108, 120, 123, 158,
160, 163, 165, 168, 192, 193, 1
94, 195, 196, 199, 200, 201, 20
2, 203, 207, 225, 226, 236, 23
7, 246, 248, 249, C.I. I. Reactive Blue 1, 2, 3, 4, 5, 7, 8, 9, 13, 14, 1
5, 17, 18, 19, 20, 21, 25, 26, 2,
7, 28, 29, 31, 32, 33, 34, 37, 3
8, 39, 40, 41, 43, 44, 46, C.I. I. Food Blue 1, 2 and the like.

Further, specific examples of black dyes include C.I. I. Acid Black 1, 2, 7, 24, 2
6, 29, 31, 48, 50, 51, 52, 58, 6
0, 62, 63, 64, 67, 72, 76, 77, 9
4, 107, 108, 09, 110, 112, 115,
118, 119, 121, 122, 131, 132, 1
39, 140, 155, 156, 157, 158, 15
9, 191, C.I. I. Direct Black 17, 19,
22, 32, 38, 51, 56, 62, 71, 74, 7
5, 77, 94, 105, 106, 107, 108, 1
12, 113, 117, 118, 132, 133, 14
6, 154, 168, C.I. I. Reactive Black 1, 3, 4, 5, 6, 8, 9, 10, 12, 13, 1
4, 18, C.I. I. Food Black 2 and the like.

In the present invention, when a dye is used as a colorant, the amount of the dye added to the ink composition is preferably 0.5 to 15% by weight, and more preferably 0.1 to 15% by weight.
7 to 10% by weight. When the content is 0.5% by weight or more, a minimum print density can be obtained when used in an ink jet recording apparatus, and when the content is 15% by weight or less,
This is advantageous because it is easy to adjust the viscosity of the ink to be printable together with other additives.

The pigments usable in the present invention include:
There is no particular limitation, and an inorganic pigment or an organic pigment can be used. As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, and a thermal method can be used. As the organic pigment, azo pigments (azo lake, insoluble azo pigment, condensed azo pigment,
Chelating azo pigments and the like), polycyclic pigments (for example,
Phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc., dye chelates (eg, basic dye chelates, acidic dye chelates, etc.), nitro Pigments,
Nitroso pigments, aniline black and the like can be used.

In the present invention, the pigment is used in a state of being dispersed in an alkaline solvent. Examples of such pigments include those classified as pigments in the color index, those stabilized and dispersed in an alkaline pH range by a dispersant, or those dispersed by performing a treatment to impart a functional group to the pigment surface. Be raised.

The pigments usable in the present invention include:
Specifically, for example, the following can be exemplified. For example, C.I. I. Pigment Yellow 1,
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 14C, 15, 16, 17, 24, 34,
35, 37, 42, 53, 55, 65, 73, 7
4, 75, 81, 83, 93, 95, 97, 98, 10
0, 101, 104, 108, 109, 110, 11
4, 117, 120, 128, 129, 138, 15
0, 151, 153, 154, 180 and the like.

Further, C.I. I. Pigment Red 1, 2,
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1
3, 14, 15, 16, 17, 18, 19, 21, 2
2, 23, 30, 31, 32, 37, 38, 39, 4,
0, 48 (Ca), 48 (Mn), 48: 2, 48:
3, 48: 4, 49, 49: 1, 50, 51, 52,
52: 2, 53: 1, 53, 55, 57 (Ca), 5
7: 1, 60, 60: 1, 63: 1, 63: 2, 64,
64: 1, 81, 83, 87, 88, 89, 90, 10
1 (Bengara), 104, 105, 106, 108 (cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 163, 1
66, 168, 170, 172, 177, 178, 17
9, 184, 185, 190, 193, 202, 20
9, 219 and the like.

Further, C.I. I. Pigment Blue 1,
2, 3, 15, 15: 1, 15: 2, 15: 3, 15:
34, 16, 17: 1, 22, 25, 56, 60, C.I.
I. Bat Blue 4, 60, 63, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51,
C. I. Pigment Green 1, 4, 7, 8, 10,
17, 18, 36, C.I. I. Pigment Violet 1 (rhodamine lake), 3, 5: 1, 16, 19 (quinacridone red), 23, 38 and the like. In addition, processed pigments such as graft carbon in which the pigment surface is treated with a resin or the like can also be used.

Examples of the black type include carbon black and C.I. I. Pigment Black 1. Specific examples of the carbon black described above include:
No.2300, No.900, MCF88, No.33, No.40, Mitsubishi Chemical
No.45, No.52, MA7, MA8, MA100, No2200B etc. are Raven5750, Raven5250, Raven5000, Raven manufactured by Columbia.
3500, Raven1255, Raven700, etc.
gal 400R, Regal330R, Regal660R, Mogul L, Monarch70
0, Monarch 800, Monarch 880, Monarch 900, Monarch
1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. are Color Black FW1, ColorBlack FW manufactured by Degussa
2, Color Black FW2V, Color Black FW18, Color Black
FW200, ColorBlack S150, Color Black S160, Color B
lack S170, Printex 35, Printex U, Printex V, Print
ex 140U, Special Black 6, Special Black 5, Special
Black4A, Special Black 4, and the like.

The dispersants usable in the present invention include, for example, styrene-acrylic acid resin, styrene-acrylic acid-acrylate resin, styrene-maleic acid resin, styrene-maleic acid half-ester resin, acrylic acid-acrylic acid Acid ester resins, isobutylene-maleic acid resins, rosin-modified maleic acid resins, and the like.

The pigment can be dispersed by a conventionally known method. The above dispersant and pigment are mixed in water made alkaline with sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, aqueous ammonia, triethanolamine, diethanolamine, triethylamine, aminomethylpropanol and the like. , This, ball mill, sand mill,
Attritor, roll mill, agitator mill, Henschel mixer, colloid mill, ultrasonic homogenizer,
The pigment is dispersed using a disperser such as a jet mill or an ong mill. At this time, the average particle size of the pigment is 25 to 10
The thickness is adjusted to 00 nm, preferably 50 to 250 nm. Further, at this time, it is preferable to carry out filtration or centrifugation using a metal filter, a membrane filter, or the like in order to remove coarse particles and foreign substances that cause clogging.

When a pigment is used as a colorant in the ink composition of the present invention, the amount of the pigment added to the ink composition is preferably 0.5 to 15% by weight, more preferably 0.7 to 15% by weight. It is 12% by weight.

In the present invention, as the colorant, a single kind may be selected from each group of the above-mentioned dyes and pigments, or a plurality of kinds may be selected from within each group or between each group and used in combination. May be used.

Humectant As the humectant in the present invention, any one can be used in the ink composition as long as it can suppress drying of the ink and prevent solidification of the ink at the discharge nozzle of the ink jet recording apparatus. Things can also be used. The humectant used in the present invention is preferably a humectant or hygroscopic material among water-soluble organic solvents, specifically, for example, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, Polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol 1,6-hexanediol, 1,2,6-hexanetriol, pentane Polyols such as erythritol; 2-pyrrolidone; N-methyl-2-pyrrolidone; Urea, thiourea, ethylene urea, ureas such as 1,3-dimethylimidazolidinone, lactams such as ε-caprolactam, trimethylolpropane, solid glycerins such as trimethylolethane, maltitol, sorbitol, Water-soluble hygroscopic materials such as saccharides such as gluconolactone and maltose can also be suitably exemplified.

These humectants have an ink viscosity of 25 mPa at 25 ° C. in combination with other components of the ink composition.
-It can be added at an addition amount of s or less.

Nonionic surfactant According to a preferred embodiment of the present invention, the ink composition further comprises a nonionic surfactant. The use of a nonionic surfactant is advantageous in that the ink composition can be sufficiently spread on recording paper even with a small amount of ink. Also,
The use of a nonionic surfactant is advantageous in that an ink composition with less foaming can be obtained as compared with an ionic surfactant.

Examples of such nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, and polyoxyethylene alkylamine. Examples thereof include ethylene alkylamide and an acetylene glycol-based surfactant described below. These can be used alone or in combination of two or more. Specific examples of the nonionic surfactant include Nissan Nonion K-211, K-220, P-213, E
-215, E-220, S-215, S-220, HS
-220, NS-212, NS-220 (all manufactured by NOF Corporation) and the like.

According to a preferred embodiment of the present invention, the ink composition preferably further comprises an acetylene glycol-based surfactant as a nonionic surfactant. In the present invention, preferred specific examples of the acetylene glycol-based surfactant include a compound represented by the following formula (a).

[0043]

Embedded image [Wherein 0 ≦ m + n ≦ 50, R ^{1 *} , R ^{2 *} , R
^{3 *} and R ^{4 * each} independently represent an alkyl group (preferably an alkyl group having 1 to 6 carbon atoms)]

Of the compounds represented by the above formula (a), particularly preferred are 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 3,6-dimethyl-4-octyne -3,6-diol, 3,5-dimethyl-1-hexyn-3-ol and the like. As the acetylene glycol-based surfactant represented by the above formula (a), a commercially available product can be used, and specific examples thereof include Surfynol 61, 82, 104, 440, 465, and 48.
5 or TG (both Air Products and Chemical
s. Inc.), Olfin STG, Olfin E1010 (trade name) (all manufactured by Nissin Chemical Co., Ltd.). These acetylene glycol-based surfactants
Two or more kinds may be mixed and added.

The addition amount of the nonionic surfactant is preferably in the range of about 0.1 to 5% by weight, more preferably in the range of about 0.5 to 2% by weight, based on the ink composition. When the amount is 0.1% by weight or more, the combined use of a glycol monoether and a 1,2-alkanediol with a penetrant makes it possible to cause the ink to land on the recording paper in the lateral direction of the paper. This is advantageous for spreading. When the content is 5% by weight or less, it becomes easy to adjust the viscosity of the ink to be printable together with other additives.

Water and Other Ingredients In the ink composition according to the present invention, the main solvent is water. Here, as water, ion exchange water, ultrafiltration water,
Pure water such as reverse osmosis water and distilled water, or ultrapure water can be preferably used. In addition, it is preferable to use water sterilized by ultraviolet irradiation and addition of hydrogen peroxide since the generation of mold, bacteria, and the like can be prevented during long-term storage. The ink composition according to the present invention may further contain other water-soluble organic solvents other than those described above.

The ink composition according to the present invention further comprises an agent for preventing clogging of a nozzle, an antiseptic / fungicide, an antioxidant,
It may further include other optional components such as an ultraviolet absorber, a conductivity adjuster, a pH adjuster, a surface tension adjuster, a dissolution aid, a viscosity adjuster, and an oxygen absorber.

Examples of the pH adjuster include alkali metal hydroxides and amines such as lithium hydroxide, sodium hydroxide, potassium hydroxide, triethanolamine, diethanolamine and aminomethylpropanol.

Examples of antioxidants and ultraviolet absorbers include allohanates such as allohanate and methyl allohanate;
L-ascorbic acid and salts thereof such as biurets such as biuret, dimethyl biuret, and tetramethyl biuret;
8, 900, 1130, 384, 292, 123, 14
4, 622, 770, 292, Irgacor 252,
153, Irganox 1010, 1076, 103
5, MD1024, etc., and also lanthanide oxides.

Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol,
-Pyridinethiol-1-oxide sodium, sodium sorbate, sodium dehydroacetate, 1,2-
It can be selected from dibenzothiazolin-3-one (Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN of ICI) and the like.

Recording Method According to the present invention, there is provided a recording method for printing by attaching the ink composition to a recording medium. Here, examples of the recording method using the ink composition include an ink jet recording method, screen printing, a recording method using a writing instrument with a pen, and other various printing methods.

According to a preferred embodiment of the present invention, there is provided an ink jet recording method for performing printing by discharging droplets of the ink composition according to the present invention and attaching the droplets to a recording medium. In the present invention, as the inkjet recording method, any method can be used as long as the ink composition is ejected as droplets from a fine nozzle and the droplets are attached to a recording medium. As such a method, for example, a method using an ink jet head having a mechanism based on the response of an electrostrictive element, that is, a pressure and a print information signal are simultaneously applied to the ink liquid by the electrostrictive element, and the ink droplet is mechanically deformed thereby. A method of performing printing by ejecting, a method of rapidly expanding the volume of the ink liquid by the action of thermal energy, and a method of applying pressure to the ink liquid with a small pump and mechanically vibrating the nozzle with a crystal oscillator or the like, There is a method of forcibly ejecting ink droplets. In addition, an electrostatic suction method may be used. In this method, a strong electric field is applied between a nozzle and an acceleration electrode placed in front of the nozzle, ink is continuously ejected from the nozzle in the form of droplets, and printing information is printed while the ink droplet flies between the deflection electrodes. This is a method in which a signal is applied to a deflecting electrode for recording, or a method in which an ink droplet is ejected in accordance with a print information signal without being deflected.

In the present invention, in the various ink jet recording methods as described above, printing is performed at a relatively low ink discharge speed of 10 m / s or less, and the ink composition according to the present invention is used. Inkjet recording can be performed stably by preventing ink from adhering to the nozzles.

Further, according to the present invention, there is also provided a recorded matter recorded by the above recording method.

[0055]

EXAMPLES The present invention will be described below in more detail with reference to examples, but these examples do not limit the scope of the present invention.

Ink compositions 1 to 11 were prepared as described below. Ink Composition 1 C.I. I. Direct black 32
6 g, glycerin 10 g, diethylene glycol 5 g, diethylene glycol monomethyl ether 1
g, 5 g of 1,2-pentanediol, 0.1 g of potassium hydroxide as a pH adjuster, and 0.5 g of aminomethylpropanol were mixed, and ultrapure water was added to make a total amount of 100 g to obtain a mixed solution. Was. The mixture was stirred for 2 hours and filtered through a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 1.2 μm to prepare Ink Composition 1.

Ink composition 2 C.I. I. 3 Direct Blue 86
g, glycerin 5 g, and triethylene glycol 10
g, 3 g of diethylene glycol monoethyl ether,
3 g of 1,2-pentanediol and 0.1 g of potassium hydroxide as a pH adjuster were mixed, and ultrapure water was added to make a total amount of 100 g to obtain a mixed solution. The mixture was stirred for 2 hours and filtered through a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 1.2 μm to prepare Ink Composition 2.

Ink Composition 3 C.I. I. Pigment Yellow 74, and Joncryl J-6, a water-soluble resin dispersant.
2 (manufactured by Johnson Polymer), 150 g of potassium hydroxide and 250 g of water were mixed and dispersed in a ball mill using zirconia beads for 10 hours. The resulting dispersion liquid was filtered through a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 8 μm to remove coarse particles, and diluted with water to a pigment concentration of 10% by weight to prepare a yellow pigment dispersion liquid 3. 30 g of the obtained yellow pigment dispersion 3, 15 g of glycerin, 1.5 g of ethylene glycol monobutyl ether, and 4 g of 1,2-pentanediol were mixed, and ultrapure water was added to make the total amount 100 g. Obtained. Furthermore, the pH of the mixture was adjusted to 9.5 with triethanolamine as a pH adjuster.
After that, the mixture was stirred for 2 hours, and filtered through a membrane filter (trade name, manufactured by Nippon Millipore Limited) having a pore size of about 1.2 μm to prepare Ink Composition 3.

Ink Composition 4 C.I. I. Pigment Blue 15 to 10
0 g, Joncryl J-62 which is a water-soluble resin dispersant
100 g (manufactured by Johnson Polymer), 4.5 g of potassium hydroxide, and 250 g of water were mixed and dispersed in a ball mill using zirconia beads for 10 hours.
The resulting dispersion liquid was filtered through a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 8 μm to remove coarse particles, and diluted with water to a pigment concentration of 10% by weight to prepare a cyan pigment dispersion liquid 4. 30 g of the obtained cyan pigment dispersion 4, 10 g of glycerin, 5 g of diethylene glycol, and 2 g of triethylene glycol monoethyl ether.
g, and 3 g of 1,2-hexanediol,
Ultrapure water was added to make the total amount 100 g to obtain a mixed solution. Further, the pH of the mixture was adjusted to 9.5 with triethanolamine as a pH adjuster, and the mixture was stirred for 2 hours, and a membrane filter having a pore size of about 1.2 μm (manufactured by Nippon Millipore Limited) was used. To prepare Ink Composition 4.

Ink Composition 5 100 g of carbon black color black S170 (manufactured by Degussa), which is a black pigment, 150 g of Joncryl J-62 (manufactured by Johnson Polymer) which is a water-soluble resin dispersant, and potassium hydroxide were used. 6 g and 2 water
After mixing 50 g, the mixture was dispersed in a ball mill using zirconia beads for 10 hours. The obtained undiluted dispersion liquid was used for a pore size of about 8
The mixture was filtered through a μm membrane filter (manufactured by Japan Millipore Limited) to remove coarse particles, and diluted with water to a pigment concentration of 10% by weight to prepare a black pigment dispersion liquid 5. 50 g of the obtained black pigment dispersion liquid 5, glycerin and 8
g, 6 g of triethylene glycol, 2 g of diethylene glycol monobutyl ether, and 2 g of 1,2-hexanediol, and added ultrapure water to make a total amount of 10 g.
The mixture was obtained as 0 g. Further, the pH of the mixture was adjusted to 9.5 with triethanolamine as a pH adjuster, and the mixture was stirred for 2 hours to obtain a mixture having a pore size of about 1.2.
Ink composition 5 was prepared by filtration through a μm membrane filter (manufactured by Nippon Millipore Limited).

Ink Composition 6 C.I. I. Direct black 32
6 g, glycerin 10 g, diethylene glycol 5 g, diethylene glycol monomethyl ether 1
g, 4 g of 1,2-pentanediol, 1.5 g of Nissan Nonion NS-220 (manufactured by NOF Corporation) which is a nonionic surfactant, 0.1 g of potassium hydroxide as a pH adjuster, and aminomethyl 0.5 g of propanol was mixed, and ultrapure water was added to make a total amount of 100 g to obtain a mixed solution. The mixture was stirred for 2 hours, and filtered through a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 1.2 μm to prepare Ink Composition 6.

Ink Composition 7 Cyanide dye C.I. I. 3 Direct Blue 86
g, glycerin 5 g, and triethylene glycol 10
g, 2 g of diethylene glycol monoethyl ether,
2 g of 1,2-pentanediol was used, and Surfynol 440 (Air-Air) was used as an acetylene glycol-based surfactant.
1 g of Products and Chemicals) and 0.1 g of potassium hydroxide as a pH adjuster were mixed, and ultrapure water was added to make a total amount of 100 g to obtain a mixed solution. The mixture was stirred for 2 hours, and filtered with a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 1.2 μm to prepare Ink Composition 7.

Ink Composition 8 A carbon black Bonjet Black CW-1 (manufactured by Orient Chemical Industry Co., Ltd.) dispersed as a black pigment by applying a functional group
g, glycerin 5 g, and triethylene glycol 10
g, 2 g of diethylene glycol monoethyl ether,
2 g of 1,2-pentanediol was used, and Surfynol 440 (Air-Air) was used as an acetylene glycol-based surfactant.
1 g of Products and Chemicals) and 0.5 g of triethanolamine as a pH adjuster were mixed, and ultrapure water was added to make a total amount of 100 g to obtain a mixed solution. This mixture is stirred for 2 hours to obtain a pore size of about 1.2 μm.
Membrane filter (manufactured by Nippon Millipore Limited)
, To prepare ink composition 8.

Ink Composition 9 Cyan pigment C.I. I. Pigment Blue 15 to 10
0 g, Joncryl J-62 which is a water-soluble resin dispersant
100 g (manufactured by Johnson Polymer), 4.5 g of potassium hydroxide, and 250 g of water were mixed and dispersed in a ball mill using zirconia beads for 10 hours.
The resulting dispersion liquid was filtered through a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 8 μm to remove coarse particles, and diluted with water to a pigment concentration of 10% by weight to prepare a cyan pigment dispersion liquid 9. 30 g of the obtained cyan pigment dispersion 9, 10 g of glycerin, 5 g of diethylene glycol, and 2 g of triethylene glycol monoethyl ether.
g, 2 g of 1,2-hexanediol, and Surfynol 44 as an acetylene glycol-based surfactant.
0 (manufactured by Air Products and Chemicals) to 1
g, and mixed with ultrapure water to make the total amount 100 g. Further, after adjusting the pH of the mixture to 9.5 with triethanolamine as a pH adjuster, the mixture was stirred for 2 hours and filtered through a membrane filter (manufactured by Nippon Millipore Limited) having a pore size of about 1.2 μm. Thus, an ink composition 9 was prepared.

Ink Composition 10 (Comparative Example) 1 g of diethylene glycol monomethyl ether and 1,2
-Ink composition 10 was prepared in the same manner as in the above ink composition 1, except that 6 g of 1,2-hexanediol was added instead of 5 g of pentanediol.

Ink Composition 11 (Comparative Example) 2 g of diethylene glycol monobutyl ether and 1,2
-Ink composition 11 was prepared in the same manner as in the above ink composition 5, except that 7 g of 1,2-hexanediol was added instead of 2 g of -hexanediol.

Evaluation Test For the ink compositions 1 to 11, the neutral plain paper Xerox-P (manufactured by Fuji Xerox Co., Ltd.) was manufactured using a piezoelectric element type on-demand ink jet recording apparatus MJ-930C (manufactured by Seiko Epson Corporation). Was printed. With respect to the obtained printed matter, print quality, missing prints, flight bending of ink droplets, and the like were confirmed for each ink composition.

Each of the ink compositions had good print quality on recording paper. Regarding the ink compositions 1 to 9, even when printing was continuously performed on 300 pages, disturbances such as missing prints and bent ink droplets did not occur. On the other hand, with respect to the ink compositions 10 and 11, which are comparative examples, the print quality was equivalent to that of the ink compositions 1 to 9, but the flight of the ink droplets gradually occurred when printing was performed continuously, 300 pages could not be printed stably. When the ejection nozzle of the ink jet recording apparatus in which the flight of the ink droplet was bent was observed with a microscope, it was presumed that the ink was attached near the nozzle, and that the flight of the ink droplet was caused.

Claims (11)

[Claims] 1. An ink composition comprising at least a colorant, a humectant, a glycol monoether, a 1,2-alkanediol, and water, wherein the glycol monoether, a 1,2-alkane An ink composition having a weight ratio to a diol in the range of 1: 5 to 5: 1. 2. The ink composition according to claim 1, wherein the weight ratio of the glycol monoether to the 1,2-alkanediol ranges from 1: 2 to 2: 1. 3. The ink composition according to claim 1, wherein the glycol monoether is glycol monobutyl ether. 4. The 1,2-alkanediol having 6 to 6 carbon atoms.
The ink composition according to any one of claims 1 to 3, wherein the composition is 8. 5. The method according to claim 1, wherein the glycol monoether is glycol monobutyl ether, and the 1,2-alkanediol is 1,2-hexanediol, and the amount of the 1,2-hexanediol is based on the total amount of the ink composition. The ink composition according to claim 1, wherein the content is less than 2.5% by weight. 6. The method according to claim 1, wherein the colorant is a water-soluble dye.
6. The ink composition according to any one of 5. 7. The pigment according to claim 1, wherein the colorant is a dispersed pigment.
6. The ink composition according to any one of 5. 8. The ink composition according to claim 1, further comprising a nonionic surfactant. 9. The ink composition according to claim 8, wherein the nonionic surfactant is an acetylene glycol-based surfactant. 10. An ink jet recording method in which droplets of an ink composition are discharged and the droplets are attached to a recording medium to perform printing, wherein the ink composition is any one of claims 1 to 9. An ink-jet recording method using the ink composition described in 1. 11. A recorded matter recorded by the recording method according to claim 10.