KR20000055023A - The composition of the pigmented ink - Google Patents

Abstract

PURPOSE: An aqueous color pigment type black ink composition which has improved printability, black chromaticity, drying time, and, water resistance, and degree of being blurred is provided by using a specifically dispersed carbon black dispersing agent through applying polyvinyl alcohol as a dispersing agent and alkoxylate as a combination. CONSTITUTION: An aqueous color pigment type black ink composition produced by mixing black coloring agent, dispersing agent, combination dispersing agent, surfactant, permeating agent, chelating agent, pH controlling agent, alcohol, and deionized water is characterized by including: (a) a single dispersed solution of carbon black introducing sulfonate group or introducing carboxylate group as a black coloring agent, or combination thereof in an amount of 2-5wt%; (b) 0.005-10wt% of polyvinyl alcohol having a molecular weight of 1000-20000 hydrolyzed 60-80mol% from polyvinylacetate as a dispersing agent, and; (c) 0.01-10wt% of a combination dispersing agent selected from a group consisting aromatic ethoxylate, phosphorous containing alkoxylate.

Description

Water-soluble pigment-type black inkjet ink composition excellent in printability {TH COMPOSITION OF THE PIGMENTED INK}

The present invention relates to a water-soluble pigment-type black inkjet ink composition having excellent printability, and more particularly, to a printing solution prepared from a dispersion of carbon black specially dispersed using polyvinyl alcohol as a dispersant and siloxylate as a combination dispersant. The present invention relates to a water-soluble pigment black inkjet ink composition having improved blackness, drying speed, and bleeding properties.

In recent years, due to the low price of inkjet printers and the ease of printing color documents, the use of ink is also increasing as the number of printers is rapidly increasing. Inks can be classified into dye type ink and pigment type ink for black and color respectively. Dye type ink is still used a lot because of its clear color and ease of use, but it is weak in heat resistance, water resistance and weather resistance, and has a strong bleeding on paper. There is a drawback and there is a tendency to switch to pigment type ink. It is because pigment-type ink is excellent in water resistance, light resistance, and heat resistance, there is little blurring between colors, and it can use for various papers. In black pigment type ink, carbon black is widely used as a colorant in terms of cost. In order to stably disperse carbon black in a solvent, a dispersant or chemical treatment of the surface of the carbon black has affinity with a solvent. Use a method of introducing special functional groups. In particular, the method of chemically modifying the surface of carbon black is polymerized by hydrophilic acrylic monomer or vinyl aromatic salt containing carboxylate, and graft reaction on carbon black or acid or ozone on the surface of carbon black. Sulfonate groups or carboxylate groups are introduced to impart hydrophilicity to the carbon black particles. Among them, the carbon black particles into which the sulfonate group or the carboxylate group are introduced have affinity with polar water by the functional group introduced on the surface, and thus may be usefully used as a black coloring agent. When ink is manufactured using such a black colorant as a raw material, it is prepared by adding a dispersant, a surfactant, a moisturizer, a chelating agent, a penetrant, and an antioxidant to improve long-term storage stability, print quality, and discharge characteristics from a nozzle. do. In this case, as the dispersant, vinyl acetate-based, vinyl pyrrolidine-based, acryl-based homopolymers or copolymers were generally used alone or in combination. However, these dispersants have dispersion stability depending on the chemical composition, molecular weight and molecular weight distribution of the dispersant. There is room for improvement because it is very different and it is not satisfactory in water resistance, print quality, long-term storage stability because it greatly affects the print quality when printing as ink.

An object of the present invention is to overcome the above-mentioned problems of the prior art, find a dispersant that can improve the quality of the final ink by applying to the carbon black into which the sulfonate group or the carboxylate group is introduced to combine the colorant-dispersant and In addition, using a new colorant-dispersant combination to find a surfactant, humectant, chelating agent, etc. to improve the quality of the final ink when preparing the ink to provide a water-soluble pigment inkjet ink composition with good print quality, water resistance and storage stability It is.

The purpose of this invention,

In the water-soluble pigment black inkjet ink composition prepared by mixing a black colorant, a dispersant, a combination dispersant, a surfactant, a humectant, a penetrant, a chelating agent, a pH adjuster, an alcohol, and deionized water,

(a) 2% by weight to 5% by weight of an aqueous dispersion of carbon black into which a sulfonate group is introduced as a black colorant and an aqueous dispersion of carbon black into which a carboxylate group is introduced;

(b) 0.005% to 10% by weight of polyvinyl alcohol having a molecular weight of 1000 to 20,000, hydrolyzed from 60% by mole to 80% by mole from polyvinylacetate as a dispersant;

(c) 0.01 wt% to 10 wt% of one selected from the group consisting of aromatic ethoxylates and phosphorus alkoxylates as a combination dispersant;

It can be achieved by providing a water-soluble pigment-type black inkjet ink composition comprising a.

That is, the present invention uses an aqueous dispersion of carbon black surface-modified as a black colorant and suitably uses a dispersant, a combination dispersant, a surfactant, a humectant, a chelating agent, and the like. Hereinafter, the present invention will be described in detail.

The black colorant is chemically treated with carbon black to increase the affinity with the aqueous solution. The CAB-O-JET 200 (CABOT) with sulfonate group and the CAB-O-JET 300 (CABOT) with carboxylate group are introduced. Can be used. The content is used from 2% by weight to 5% by weight.

The dispersant serves to stably disperse the pigment into the fine particles in the solvent and increases the flowability and adhesion to the paper at the nozzle during printing. The dispersant used in the present invention is a polyvinyl alcohol having a molecular weight of 500 to 50000. You can use one, even better, use something between 1000 and 20000. If the molecular weight exceeds this range, printability is poor and nozzle clogging occurs. Polyvinyl alcohol is hydrolyzed from 50 to 90 mol%, more preferably from 60 to 80 mol%, from polyvinylacetate, so that when the degree of hydrolysis exceeds this range, printability and adhesion to paper are reduced. The polyvinyl alcohol may be used in an amount of 0.005% by weight to 10% by weight, and more preferably, 0.05% by weight to 5% by weight. If it is less than 0.005% by weight, the flowability and dispersion stability are not effective. If it exceeds 10% by weight, the black pigment dries quickly in the nozzle, causing the nozzle to become clogged.

To maximize the dispersing effect and printability, either aromatic ethoxylate or phosphorus-containing ethoxylate can be used as a combination dispersant with polyvinyl alcohol, which affects the flowability and storage stabilization when ink is ejected from the head. Crazy The used content can be used from 0.01% by weight to 10% by weight, it is not effective when less than 0.01% by weight, but rather destroys storage stability and is effective even when it exceeds 10% by weight, but the cost increases.

The surfactant lowers the surface tension of the ink to increase the kneading properties of each composition to increase the flowability, and the usable surfactants include sodium dioctylsulfosuccinate, sodium dicyclohexylsulfosuccinate, sodium dia Wheat sulfosuccinate, sodium dioctyl sulfosuccinate, sodium diisobutyl sulfosuccinate, alkylamineguanidine polyoxyethanol, disodium ethoxylate alcohol half ester of sulfosuccinic acid, disodium ethoxylate nonylphenol of sulfosuccinic acid Half ester, sodium diamyl sulfosuccinate, ammonium salt of sulfate nonylphenoxy polyethyleneoxyethanol, ammonium salt of sulfate nonylphenoxy polyethyleneoxyethanol, disodium mono & dididodecyl diphenyloxide disulfonate, sodium diisopropylnaphthalene sulfonate , 2,4,7,9-tetramethyl-5-decine-4,7-polyethyl Oxyethanol (EO content: 10 mol), 2,4,7,9-tetramethyl-5-decine-4,7-diol, 2,4,7,9-tetramethyl-5-decine-4,7- Polyethyleneoxyethanol (EO content: 1.3 mol), a mixture of acetylenediol / nonionic surfactant / anionic dispersant, octylphenoxy polyethyleneoxyethanol (FW 294.44), octylphenoxy polyethyleneoxy as an acetylenic glycol and a nonionic surfactant Ethanol (FW 426.60), octylphenoxy polyethyleneoxyethanol (FW 734.97), nonylphenoxy polyethyleneoxyethanol (FW 308.47), nonylphenoxy polyethyleneoxyethanol (FW 440.63), nonylphenoxy polyethyleneoxyethanol (FW 749.00), Nonylphenoxy polyethyleneoxyethanol (FW 1982.50), nonylphenoxy polyethyleneoxyethanol (FW 4625.72), dialkylphenoxy polyethyleneoxyethanol, polyoxyethylene nonylphenol ether and the like can be used. To use in combination It is preferable. Among them, the polyethyleneoxyethanol series and the aerosol series alone or in combination can be used from 0.001% to 7% by weight, and less than 0.001% by weight are not effective. There is a disadvantage that a large amount of foam occurs. Moisturizers increase the flow of ink and delay the drying of moisture in the print head, preventing the colorant from drying out and preventing the nozzles from clogging. And when printed on paper, print quality is affected. Moisturizers that can be used include 2-pyrrolidinone, N-methyl-2-pyrrolidinone, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (molecular weight 200, 300, 400, 600, 800, 1000, 2000 , 4000, 6000), propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin, 1,2,4-butanetri All, 2,2-thiodiethanol, ethylene carbonate, dimethyl sulfoxide, γ-butyrolactone, N, N-dimethylformamide, etc. may be used alone, but two or more of these moisturizing agents may be used to improve print quality. Used in combination in proportions. Among them, (i) polyethylene glycol (molecular weight 200, 300, 400, 600, 800, 1000, 2000, 4000, 6000) or 5 to 20% by weight of 1,4-butanediol or 1,5-pentanediol and (ii ) 5 to 20% by weight of 2-pyrrolidinone is used singly or in combination. The total moisturizer content is 10% to 40% by weight. When the content of the moisturizer is less than 10% by weight, the flowability of the ink decreases and the printability is poor. The drying time of the ink in Esau is disadvantageous, causing contamination on the next printed matter.

Penetrants allow the ink to penetrate into the paper quickly when the ink comes into contact with the paper, thus increasing the drying speed. Penetrating agents include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, propylene Glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monopropyl ether, polyethylene glycol monomethyl ether (molecular weight 550, 750) and the like. It can be used alone or in combination.

Metal ions capable of forming insoluble salts cause clogging of the nozzles by blocking the flow path of the ink in the cartridge, and to solve this problem, a chelating agent which brings inertness of the metal ions may be used. Chelating agents include tetrasodium pyrophosphate, sodium phosphate, tetrasodium ethylenediaminetetraacetate, disodium ethylenediaminetetraacetate, tetrasodium diethylenetriaminepentaacetate, trisodium hydroxide ethyl ethylenediaminetetraacetate, morpholine, thiomorpholine, Triethanolamine ethylenediamine tetraacetate etc. can be used. Among them, trisodium ethyl ethylene diamine tetraacetate or triethanolamine ethylenediamine tetraacetate is preferably used in an amount of 0.01% by weight to 5% by weight, and when the content is less than 0.01% by weight, the effect is insignificant. If exceeded, penetration into paper becomes severe and feather spreading increases.

In addition, by maintaining a proper pH to maintain the stability of the ink for this purpose using a pH adjuster. Dimethylethanolamine, triethylamine, triethanolamine, sodium hydroxide, ammonium hydroxide, etc. can be used as a pH adjuster.

In addition, alcohol is used to increase the drying rate, and ethanol, propanol, butanol, isopropanol, isobutyl alcohol, 2-methylpropanol, and the like may be used.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but these Examples are only for the purpose of illustrating the present invention, and the claims are not limited by these examples.

<Example 1>

4% by weight of CAB-O-JET 300 (CABOT), 1% by weight of polyvinyl alcohol, 0.2% by weight of SOLSPERSE 27000, 20% by weight of 2-pyrrolidinone, 3% by weight of isopropyl alcohol and 71.8% by weight of deionized water , Ink was prepared, and an image was output on a general copy paper (Hansol copy paper) using an inkjet printer (Deskjet 870K, manufactured by Hewlett-Packard Co.). Physical properties such as printability, blackness, water resistance, and storage stability of the printed matter were evaluated, and the results are shown in [Table 2].

<Example 2> to <Example 16> and <Comparative Example 1> to <Comparative Example 7> were also tested by the same method, and the results are shown together in [Table 2]. The specific mixing ratios are shown in [Table 1]. Same as

[Explanation of the table]

Black Colorant ①: CAB-O-JET 200 Black Colorant ②: CAB-O-JET 300

Surfactant ①: Sodium dioctylsulfosuccinate

Surfactant②: polyoxyethylene nonylphenol ether

Moisturizer ①: Polyethylene glycol Moisturizer ②: 1,4-butanediol

Moisturizer ③: 1,5-pentanediol Moisturizer ④: 2-pyrrolidinone

Chelating agent ①: 3-sodium hydroxide ethyl ethylenediamine tetraacetate

Chelating agent ②: triethanolamine ethylenediamine tetraacetate

Alcohol: Isopropyl Alcohol

Dispersant ㉮: JONCRYL682 (from Johnson Plymer)

Dispersing agent: ACUMER1000 (Rom & Haas)

Dispersant SN: SN-DISPERSANT (manufactured by Novops, Korea)

Dispersant BE: BEVALOID226 (from Long Franca)

Evaluation item example Print Black degree Water resistance Storage stability Example 1 ◎ ○ ◎ Good Example 2 ○ ○ ◎ Good Example 3 ◎ ○ ◎ Good Example 4 ◎ ○ ◎ Good Example 5 ◎ ◎ ◎ Good Example 6 ◎ ○ ◎ Good Example 7 ◎ ○ ◎ Good Example 8 ◎ ○ ◎ Good Example 9 ◎ ◎ ◎ Good Example 10 ◎ ◎ ◎ Good Example 11 ◎ ○ ◎ Good Example 12 ◎ ◎ ◎ Good Example 13 ◎ ◎ ◎ Good Example 14 ◎ ◎ ◎ Good Example 15 ◎ ◎ ◎ Good Example 16 ◎ ◎ ◎ Good Comparative Example 1 △ ○ ○ Good Comparative Example 2 ○ ◎ ◎ Good Comparative Example 3 △ ○ ◎ Good Comparative Example 4 ○ ◎ ◎ Good Comparative Example 5 △ ○ ○ usually Comparative Example 6 △ ○ △ Bad Comparative Example 7 △ ○ ○ usually

[Explanation of the table]

◎: Excellent ○: Good △: Normal ×: Poor

The ink prepared according to the present invention using a combination of polyvinyl alcohol and alkoxylate and adding a surfactant and a moisturizing agent was excellent in printability, blackness, water resistance and storage stability, and polyvinyl alcohol and alkoxyl. The ink when only one of the rates was used was inferior in printability. In the case of using neither polyvinyl alcohol nor alkoxylate, printing, blackness, water resistance, and storage stability were poor.

[Property evaluation method]

1) Printability: 3.4cm × 18.3cm of strips were observed for spreading of unprinted parts and sides during printing.

2) Water resistance: A black strip of 3.4 cm x 18.3 cm was immersed in 4.5 cm water for 10 seconds in the longitudinal direction, and then taken out to observe the flow and spread of ink visually.

3) Storage Stability: After two hours of storage at -20 ° C and two hours of storage at 70 ° C, the aggregates were observed.

The water-soluble pigment inkjet ink composition according to the present invention has better water resistance, blackness and storage stability than the conventional ink, and especially shows excellent properties in printability, so the ink composition according to the present invention is useful for thermal and piezoelectric inkjet inks. Can be used.

Claims (7)

In the water-soluble pigment black inkjet ink composition prepared by mixing a black colorant, a dispersant, a combination dispersant, a surfactant, a humectant, a penetrant, a chelating agent, a pH adjuster, an alcohol, and deionized water, (a) 2% by weight to 5% by weight of an aqueous dispersion of carbon black into which a sulfonate group is introduced as a black colorant and an aqueous dispersion of carbon black into which a carboxylate group is introduced; (b) 0.005% to 10% by weight of polyvinyl alcohol having a molecular weight of 1000 to 20,000, hydrolyzed from 60% by mole to 80% by mole from polyvinylacetate as a dispersant; (c) 0.01 wt% to 5 wt% of a combination dispersant selected from the group consisting of aromatic ethoxylates and phosphorus-containing alkoxylates; A water-soluble pigment black inkjet ink composition comprising a. The method of claim 1, Sodium dioctylsulfosuccinate, sodium dicyclohexylsulfosuccinate, sodium diamylsulfosuccinate, sodium dioctylsulfosuccinate, sodium diisobutylsulfosuccinate, alkylamineguanidine polyoxyethanol, sulfo Disodium ethoxylate alcohol half ester of succinic acid, disodium ethoxylate nonylphenol half ester of sulfosuccinic acid, sodium diamyl sulfosuccinate, ammonium salt of sulfate nonylphenoxy polyethyleneoxyethanol, ammonium salt of sulfate nonylphenoxy polyethyleneoxyethanol Sodium mono & didodecyl diphenyloxide disulfonate, sodium diisopropylnaphthalenesulfonate, 2,4,7,9-tetramethyl-5-decine-4,7-polyethyleneoxyethanol (EO content: 10 mol ), 2,4,7,9-tetramethyl-5-decine-4,7-diol, 2,4,7,9-tetramethyl-5-decine-4,7-polyethyleneoxyethanol (EO content: 1.3 Mall), A mixture of cetylenediol / nonionic surfactant / anionic dispersant, octylphenoxy polyethyleneoxyethanol (FW 294.44), acetylenic glycol and nonionic surfactant, octylphenoxy polyethyleneoxyethanol (FW 426.60), octylphenoxy polyethylene Oxyethanol (FW 734.97), nonylphenoxy polyethyleneoxyethanol (FW 308.47), nonylphenoxy polyethyleneoxyethanol (FW 440.63), nonylphenoxy polyethyleneoxyethanol (FW 749.00), nonylphenoxy polyethyleneoxyethanol (FW 1982.50) , Nonylphenoxy polyethyleneoxyethanol (FW 4625.72), dialkylphenoxy polyethyleneoxyethanol, polyoxyethylene nonylphenol ether group consisting of 0.001% to 7% by weight alone or in combination of two or more A water-soluble pigment black inkjet ink composition. The method of claim 1, As a moisturizing agent, in the group consisting of polyethylene glycol, 1,4-butanediol, and 1,5-pentanediol, 5% to 20% by weight of a mixture of two or more thereof, and 5% to 20% by weight of 2-pyrrolidinone A water-soluble pigmented black inkjet ink composition comprising 10% by weight to 40% by weight. The method of claim 3, Water-soluble pigment black inkjet ink composition, characterized in that the polyethylene glycol is selected from the group consisting of those each having a molecular weight of 200, 300, 400, 600, 800, 1000, 2000, 4000, 6000 or a combination of two or more . The method of claim 1, A water-soluble pigmented black inkjet ink composition comprising 0.01 to 10 wt% of 3-sodium ethyl ethylenediaminetetraacetate or triethanolamineethylenediaminetetraacetate as a chelating agent alone or in combination of both. In the water-soluble pigment black inkjet ink composition prepared by mixing a black colorant, a dispersant, a combination dispersant, a surfactant, a humectant, a penetrant, a chelating agent, a pH adjuster, an alcohol, and deionized water, (a) 2% by weight to 5% by weight of an aqueous dispersion of carbon black into which a sulfonate group is introduced as a black colorant and an aqueous dispersion of carbon black into which a carboxylate group is introduced; (b) 0.005% to 10% by weight of polyvinyl alcohol having a molecular weight of 1000 to 20,000, hydrolyzed from 60% by mole to 80% by mole from polyvinylacetate as a dispersant; (c) 0.01 wt% to 5 wt% of a combination dispersant selected from the group consisting of aromatic ethoxylates and phosphorus-containing alkoxylates; (d) Sodium dioctylsulfosuccinate, sodium dicyclohexylsulfosuccinate, sodium diamylsulfosuccinate, sodium dioctylsulfosuccinate, sodium diisobutylsulfosuccinate, alkylamineguanidine polyoxy as a surfactant Ethanol, disodium ethoxylate alcohol half ester of sulfosuccinic acid, disodium ethoxylate nonylphenol half ester of sulfosuccinic acid, sodium diamyl sulfosuccinate, sulfate nonylphenoxy polyethyleneoxyethanol ammonium salt, sulfate nonylphenoxy polyethyleneoxy Ammonium Salt of Ethanol, Disodium Mono & Didodecyl Diphenyloxide Disulfonate, Sodium Diisopropylnaphthalenesulfonate, 2,4,7,9-Tetramethyl-5-decine-4,7-polyethyleneoxyethanol (EO Content : 10 mol), 2,4,7,9-tetramethyl-5-decine-4,7-diol, 2,4,7,9-tetramethyl-5-decine-4,7-polyethyleneoxyethanol (EO Content: 1.3mol), A mixture of acetylenediol / nonionic surfactant / anionic dispersant, octylphenoxy polyethyleneoxyethanol (FW 294.44), octylphenoxy polyethyleneoxyethanol (FW 426.60), octylphenoxy polyethyleneoxy as an acetylenic glycol and a nonionic surfactant Ethanol (FW 734.97), nonylphenoxy polyethyleneoxyethanol (FW 308.47) nonylphenoxy polyethyleneoxyethanol (FW 308.47) 20, nonylphenoxy polyethyleneoxyethanol (FW 749.00), nonylphenoxy polyethyleneoxyethanol (FW 1982.50), 0.001% to 7% by weight of nonylphenoxy polyethyleneoxyethanol (FW 4625.72), dialkylphenoxy polyethyleneoxyethanol and polyoxyethylene nonylphenol ether alone or in combination of two or more thereof; (e) 5% to 20% by weight alone or a mixture of two or more and 5% to 20% by weight of 2-pyrrolidinone in the group consisting of polyethylene glycol, 1,4-butanediol and 1,5-pentanediol as a moisturizing agent 10 wt% to 40 wt% in combination (f) 0.01 to 10 wt% of 3-sodium ethyl ethylenediaminetetraacetate or triethanolamineethylenediaminetetraacetate as a chelating agent alone or in combination of the two; A water-soluble pigment black inkjet ink composition comprising a The method of claim 6, Water-soluble pigment black inkjet ink composition, characterized in that the polyethylene glycol is selected from the group consisting of those each having a molecular weight of 200, 300, 400, 600, 800, 1000, 2000, 4000, 6000 or a combination of two or more