JP2000160073A - Ink composition for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink composition which gives a good image and is excellent in preservation stability and printing stability by incorporating at least a coloring material, a nonionic surfactant and monoethanolamine or diethanolamine. SOLUTION: A coloring material is preferably a dye or a pigment. When the coloring material is a pigment, it is preferable that a watersoluble dispersant is further incorporated and that the water-soluble dispersant is a homopolymer or a copolymer comprising at least one of a styrene unit, an acrylic unit and an acrylic acid unit (e.g. a styrene-acrylic acid copolymer). A nonionic surfactant is preferably acetylene glycol-based surfactant (e.g. a compound of the formula: 0<=m+n<=50; and R1-4 are each an alkyl). The coloring material is preferably C.I. pigment orange 36, C.I. pigment green 7, C.I. pigment blue 15:3, C.I. pigment red 122, C.I. pigment yellow 74 or carbon black.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for ink jet recording.

2. Description of the Related Art An ink jet recording method is a printing method in which small droplets of an ink composition fly and adhere to a recording medium such as paper to perform printing. This method has a feature that high-resolution and high-quality images can be printed at a high speed with a relatively inexpensive device.

[0003] Ink compositions used for ink-jet recording generally contain water as a main component, and further contain a coloring component and a wetting agent such as glycerin for the purpose of preventing clogging. As the colorant used in the ink composition for ink jet recording, a large number of water-soluble dyes are used because of high chroma of the colorant, a wide variety of available colorants, and solubility in water. I have.

However, on the other hand, dyes are sometimes inferior in various properties such as light resistance and water resistance, and printed matter printed with the dye ink composition is inferior in light resistance and water resistance. The water resistance has been improved by a recording paper exclusively for inkjet recording having an ink absorbing layer, but it has not been sufficient for plain paper.

[0005] Pigments are superior to dyes in light resistance and water resistance. In recent years, pigments have been studied for use as colorants in ink compositions for ink jet recording for the purpose of improving light resistance and water resistance. Here, since the pigment is generally insoluble in water, when the pigment is used in an aqueous ink composition, the pigment is mixed with a resin called a dispersant, and the like.
It is necessary to prepare as an ink composition after stably dispersing in water.

In order to stably disperse a pigment in an aqueous system, it is necessary to consider the type and particle size of the pigment, the type of resin to be used, the dispersing means, and the like. Proposed. For example, in Japanese Patent Application Laid-Open No. Hei 3-252467, water, styrene-
An ink composition comprising a maleic acid copolymer, ε-caprolactam, and a pigment has been proposed.
JP-79680-A proposes an ink composition containing an aqueous medium, a styrene-maleic acid copolymer, and a copper phthalocyanine pigment.

When considering the use of a pigment as a colorant for an ink jet recording ink, the pigment is excellent in light resistance and water resistance as compared with the dye, but the available types of the colorant are smaller than the dye. When actually used as an ink for ink jet recording, it is necessary to sufficiently consider the hue in addition to the light fastness and the water fastness.

Further, it has been proposed to increase the permeability of the ink composition, shorten the drying time, and form large pixels (for example, dots) with a small amount of ink. However, in the case of the pigment-based ink composition, when the permeability is not sufficiently given in relation to the pigment and other components,
In some cases, the penetrant impaired the stable dispersibility of the pigment.

[0009]

SUMMARY OF THE INVENTION The present inventors have now reported that an ink composition containing a combination of a nonionic surfactant as a penetrating agent and monoethanolamine or diethanolamine has excellent storage stability and printing stability and has good The knowledge of giving an image was obtained.

Accordingly, an object of the present invention is to provide an ink composition which is excellent in storage stability and printing stability and realizes a good image.

[0011] The ink composition according to the present invention comprises at least a coloring material, a nonionic surfactant, and monoethanolamine or diethanolamine.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The ink composition according to the present invention basically comprises at least a coloring material, a nonionic surfactant, and monoethanolamine or diethanolamine. The ink composition according to the present invention has an advantage that storage stability and printing stability are excellent, and a good image can be realized.

Monoethanolamine or diethanol
By adding the amine monoethanolamine or diethanolamine, good ejection stability from the nozzle in the inkjet recording method can be obtained. More specifically, after printing for a certain time, after printing is interrupted (for example, about one hour), and when printing is started again, ink droplets are not ejected from some nozzles, a phenomenon called so-called nozzle missing, A phenomenon called flight bending in which ink droplets are ejected from a nozzle out of a predetermined trajectory may be observed. According to the ink composition of the present invention, there is obtained an advantage that the nozzle missing does not occur and even if the nozzle missing occurs, it is eliminated in a short time. In addition, printing with extremely little flight deflection is possible. The lower limit of the amount of monoethanolamine or diethanolamine added to the ink composition is preferably about 0.1% by weight, more preferably about 0.2% by weight.
% By weight, and the upper limit thereof is preferably about 0.5% by weight, more preferably 0.3% by weight or less.

Nonionic surfactant The ink composition according to the present invention further comprises a nonionic surfactant.

Specific examples of the nonionic surfactant include:
Examples thereof include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, fatty acid monoglyceride, sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, polyoxylen-added acetylene alcohol, and acetylene glycol-based surfactant.

Preferred specific examples of the acetylene glycol-based surfactant include a compound represented by the following formula (I).

[0017]

Embedded image

(Where 0 ≦ m + n ≦ 50, R ¹ , R ² , R
³ and R ⁴ are independently an alkyl group)

As the compound represented by the formula (I), a commercially available product can be used. Specific examples thereof include Olphin Y, Surfynol 82, Surfynol 440,
Surfynol 465 and Surfinol 485 (both manufactured by Air Products and Chem)
icals. Inc. ) And the like. These may be used alone or in combination of two or more.

Coloring Material The coloring material contained in the ink composition used in the present invention may be a dye or a pigment.

The dyes include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes,
Various dyes usually used for ink jet recording, such as a soluble vat dye and a reactive disperse dye, can be used. As the pigment, inorganic pigments and organic pigments can be used without any particular limitation. 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. Examples of the organic pigment include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelated azo pigments, etc.), and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines) Pigments, thioindigo pigments, isoindolinone pigments,
Quinofurarone pigments, dye chelates (eg, basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.

According to a preferred embodiment of the present invention, these pigments are preferably added to the ink as a pigment dispersion obtained by dispersing in an aqueous medium with a dispersant or a surfactant. As a preferred dispersant, a dispersant commonly used for preparing a pigment dispersion, for example, a water-soluble dispersant can be used. Examples of preferred water-soluble dispersants will be described later.

The amount of the pigment added to the ink is 0.5 to 25.
% By weight, more preferably 2 to 15% by weight.
It is about.

According to a preferred embodiment of the present invention, the coloring material comprises:
C. I. Pigment Orange 36, C.I. I. Pigment Green 7, C.I. I. Pigment Blue 15: 3, C.I.
I. Pigment Red 122, C.I. I. In the ink composition which is Pigment Yellow 74 or carbon black, the above-mentioned nozzle missing can be further effectively prevented.

Water-soluble dispersant When the coloring material is a pigment in the present invention, examples of a preferred dispersant used for dispersing the pigment include one type selected from a styrene unit, an acrylic unit, and an acrylic acid unit. Alternatively, a homopolymer or a copolymer composed of two or more types may be used. More specifically,
(A) Acrylic acid polymer, styrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-acrylic acid ester (lower alkyl ester of about C1 to C4, the same applies hereinafter) copolymer Styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylate copolymer, (b) maleic acid polymer,
Styrene-maleic acid copolymer, styrene-α-methylstyrene-maleic acid copolymer, styrene-acrylate-maleic acid copolymer, styrene-methacrylic ester-maleic acid copolymer, (c) styrene- Acrylic acid ester-styrene sulfonic acid copolymer, styrene-methacryl sulfonic acid copolymer, styrene-acrylic acid ester-allyl sulfonic acid copolymer, (d) and a combination thereof are mentioned.

The water-soluble dispersant is preferably used after being alkali-neutralized with a basic substance. Preferred examples of the basic substance include ammonia, triethanolamine, N, N-
Organic amines such as diethylethanolamine, triisopropanolamine, diethylamine, triethylamine, and morpholine; metals such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; and combinations thereof.

The amount of the water-soluble dispersant added is preferably about 0.5 to 50.0% by weight, more preferably about 2.0 to 45.0% by weight, based on the pigment.

Water and Other Ingredients In the ink composition according to the present invention, water is the main solvent. As the water, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. In addition, it is preferable to use water sterilized by ultraviolet irradiation, addition of hydrogen peroxide, or the like, since the generation of mold and bacteria can be prevented when the ink composition is stored for a long period of time.

According to a preferred embodiment of the present invention, the ink composition according to the present invention preferably further comprises 1 to 15% by weight of an alkyl ether derivative of a polyhydric alcohol having 3 or more carbon atoms. Specific examples of such alkyl ether derivatives of polyhydric alcohols include diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether.

[0030] The ink composition according to the present invention preferably comprises an organic solvent. This organic solvent is preferably a low-boiling organic solvent, and preferred examples thereof include methanol, ethanol, n-propyl alcohol, iso-
Propyl alcohol, n-butanol, sec-butanol, tert-butanol, iso-butanol, n
-Pentanol and the like. Particularly, a monohydric alcohol is preferable. The low-boiling organic solvent has the effect of shortening the drying time of the ink composition on the recording medium.

According to a preferred embodiment of the present invention, the ink composition used in the present invention preferably further contains a high-boiling organic solvent. Preferred examples of the high boiling organic solvent include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, Polyhydric alcohols such as trimethylolethane, trimethylolpropane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether,
Alkyl ethers of polyhydric alcohols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, and triethylene glycol monoethyl ether; urea; 2-pyrrolidone; N-methyl-2-pyrrolidone; Dimethyl-2-imidazolidinone, triethanolamine and the like.

The amount of the low boiling organic solvent to be added is preferably 0.5 to 10% by weight of the ink composition, more preferably 1.5 to 10% by weight.
-6% by weight. The amount of the high-boiling organic solvent to be added is preferably 0.5 to 40% by weight of the ink composition.
More preferably, it is in the range of 2 to 20% by weight.

According to a preferred embodiment of the present invention, the ink composition according to the present invention may contain a surfactant.
Examples of preferred surfactants include anionic surfactants (for example, sodium dodecylbenzenesulfonate, sodium laurate, ammonium salts of polyoxyethylene alkyl ether sulfate, and the like), or a mixture of two or more thereof. Can be used.

According to a preferred embodiment of the present invention, the ink composition according to the present invention may contain sugar. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucosyl Sorbitol, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a sugar in a broad sense, and is used to include a substance widely existing in nature such as alginic acid, α-cyclodextrin, and cellulose.

The derivatives of these saccharides include reducing sugars of the aforementioned saccharides (for example, sugar alcohols (formula H
OCH ₂ (CHOH) n CH ₂ OH (where n = 2 to 5)
Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thiosugars and the like. In particular, sugar alcohols are preferred, and specific examples include maltitol and sorbitol.

The content of these saccharides is suitably in the range of 0.1 to 40% by weight, preferably 0.5 to 30% by weight of the ink composition.

In addition, if necessary, a pH adjuster, a preservative, a fungicide, and the like may be added.

[0038]

EXAMPLES Preparation of Ink Compositions Ink compositions of Examples 1 to 9 and Comparative Examples 1 to 6 containing the pigment and monoethanolamine (MEA) in the amounts (% by weight) shown in the table and having the following compositions: Was manufactured.

Pigment Amount in the table Styrene-acrylic acid copolymer (dispersant) 1% by weight Sucrose 0.7% by weight Maltitol 6.3% by weight Glycerin 15% by weight 2-Villolidone 2% by weight Orphine E1010 1% by weight Monoethanolamine Amount in table Pure water

The pigment and the dispersant were mixed and dispersed together with glass beads (1.7 mm in diameter, 1.5 times (weight) of the mixture) in a sand mill for 2 hours. Thereafter, the glass beads were removed, other components were added, and the mixture was stirred at room temperature for 20 minutes. The mixture was filtered through a 5 μm membrane filter to obtain an ink composition.

The obtained ink composition was subjected to the following evaluation test. Evaluation 1 : Printing Stability Each ink was filled in a black head of an inkjet printer MJ8000C (manufactured by Seiko Epson Corporation), and a pattern in which text and graphics were mixed was printed for 1 hour. After printing, printing was interrupted for one hour. Thereafter, missing dots or print bending when printing was resumed were observed, and the results were evaluated according to the following criteria. Evaluation A: No missing dots / bending occurred. Evaluation B: Missing dots / bending occurred.
自然 Spontaneous recovery by printing within 1 page Evaluation C: Missing dots / bending occurs, and it takes 3-4 pages or more for A4 paper before natural recovery

Evaluation 2 : Ink Stability Each ink was attached to a sample bottle in an amount of 50 cc, sealed, and allowed to stand in a thermostat at 60 ° C. for one week. The change in viscosity of the ink before and after standing was observed. The results were evaluated according to the following criteria. Evaluation A: Increase in viscosity is 0.1 mPa · s or less Evaluation B: Increase in viscosity is 0.1 mPa · s or more and 0.3 Pa · s
s or less Evaluation C: Increase in viscosity is 0.3 mPa · s or less

The above results were as shown in the following table.

[0044]

[Table 1]

Continued on front page F-term (reference) 2C056 EA13 FC02 2H086 BA02 BA53 BA55 BA59 4J039 AD02 AD03 AD09 AD10 AD14 BA04 BC09 BC12 BC17 BC35 BC39 BC60 BE01 BE02 BE22 CA06 EA15 EA16 EA17 EA20 EA21 EA42 EA44 EA46 GA24

Claims (7)

[Claims] 1. An ink composition for ink jet recording, comprising at least a coloring material, a nonionic surfactant, and monoethanolamine or diethanolamine. 2. The ink composition according to claim 1, wherein the coloring material is a dye or a pigment. 3. When the coloring material is a pigment, the coloring material further comprises a water-soluble dispersant, wherein the water-soluble dispersant comprises a styrene unit,
3. The ink composition according to claim 1, wherein the ink composition is a homopolymer or a copolymer composed of one type or two or more types selected from an acrylic unit and an acrylic acid unit. 4. 4. The ink composition according to claim 1, wherein the nonionic surfactant is an acetylene glycol-based surfactant. 5. The method according to claim 1, wherein the coloring material is C.I. I. Pigment Orange 3
6, C.I. I. Pigment Green 7, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Red 122,
C. I. The ink composition according to any one of claims 1 to 4, which is Pigment Yellow 74 or carbon black. 6. An ink jet recording method in which droplets of an ink composition are ejected, and the droplets are attached to a recording medium to perform printing, wherein the ink composition is any one of claims 1 to 5. An ink jet recording method using the ink composition described in the above. 7. A recorded matter recorded by the recording method according to claim 6.