JPH10120957A - Ink composition for ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink composition for stable ink-jet recording apparatus, having a concentration sufficient for ink-jet recording, providing a clear image not bleeding at a printed part, preventing a recorded image from bleeding and fading with water and sweat, keeping a color from becoming dull by color mixture, having no change in quality of image even in long-term preservation of a printed matter, excellent in light resistance, causing neither change in physical properties nor precipitate. SOLUTION: A water-soluble dye is dissolved in an aqueous dispersion of resin fine particles obtained by subjecting a vinyl monomer to emulsion polymerization by using a polymerizable surfactant and is heat-treated under atmospheric pressure or under pressure to produce an aqueous dispersion of colored resin fine particles for ink. The aqueous dispersion of the colored resin fine particles is diluted with water and a water-soluble organic solvent to 3-30wt.% resin content to give the objective ink composition for ink-jet recording.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aqueous dispersion of colored resin fine particles for ink and an ink composition for an ink jet recording apparatus.

[0002]

2. Description of the Related Art As a conventional ink composition for an ink jet recording apparatus, a water-soluble acid dye or a basic dye is dissolved in an aqueous medium, and additives such as a wetting agent, a pH adjusting agent and a preservative are added. Additive ink compositions and the like are known. However, in these ink compositions, the printed portion bleeds and the image becomes unclear, or the image recorded due to the water solubility of the dye causes bleeding or disappearance with sweat or water, and the color becomes cloudy due to color mixing. There is a disadvantage that. Essentially, water-soluble dyes have poor light fastness, and there is a problem that the quality of an image deteriorates when a printed matter is stored for a long period of time. In addition, these ink compositions change the physical properties of the ink or cause sedimentation due to long-term storage or repeated printing, causing clogging and ejection of nozzles to cause significant troubles, resulting in poor printing. There are drawbacks.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and problems of the conventional ink composition for an ink jet recording apparatus, and is a base of the ink composition. An object of the present invention is to provide a method for producing a stable aqueous dispersion of colored resin fine particles for ink, which does not generate a precipitate having a sufficient concentration. In addition, images recorded by water and sweat do not bleed or disappear,
An object of the present invention is to provide an ink composition for an ink jet recording apparatus which gives a clear image in which a printed portion does not bleed, does not deteriorate the image even when the printed matter is stored for a long period of time, has excellent light fastness, and does not become cloudy due to color mixing.

[0004]

Means for Solving the Problems As a result of various studies to solve the above problems, the present inventors have found that an aqueous dispersion of vinyl resin fine particles obtained by emulsion polymerization by a specific method is used.
The inventors have found that an excellent aqueous dispersion of colored resin fine particles for ink can be obtained by dissolving a water-soluble dye and performing a heat treatment, thereby completing the present invention.

The process for producing an aqueous dispersion of colored resin fine particles for an ink of the present invention comprises dissolving a water-soluble dye in an aqueous dispersion of resin fine particles obtained by emulsion polymerization of a vinyl monomer using a polymerizable surfactant. It is characterized by performing a heat treatment.

The ink composition for an ink jet recording apparatus of the present invention is prepared by dissolving a water-soluble dye in an aqueous dispersion of resin fine particles obtained by emulsion-polymerizing a vinyl monomer using a polymerizable surfactant, followed by heat treatment. And an aqueous dispersion of colored resin fine particles for ink prepared by application. Preferably, the colored resin fine particle aqueous dispersion for ink contains 3 to 30% by weight (resin solid content).

[0007]

DETAILED DESCRIPTION OF THE INVENTION An aqueous dispersion of resin fine particles obtained by emulsion polymerization according to the production method of the present invention is prepared by using a vinyl monomer and a polymerizable surfactant to form ammonium persulfate,
It is prepared by a usual emulsion polymerization method using potassium persulfate, hydrogen peroxide or the like as a polymerization initiator or, if necessary, a reducing agent in combination. The aqueous dispersion of resin fine particles obtained as described above is usually obtained as a concentrated liquid having a resin solid content of 20 to 50% by weight.

The production of the aqueous dispersion of colored resin fine particles for ink of the present invention is carried out by dissolving a water-soluble dye in the aqueous dispersion of fine resin particles described above and subjecting the aqueous dispersion to heat treatment under stirring or at atmospheric pressure or under pressure. Will be Heat treatment conditions are 50-1
50 ° C., 1 to 12 hours. By performing this heat treatment, the dye obtained by first dissolving in the aqueous medium penetrates into the resin fine particles and exhibits a vivid color.

The vinyl monomer used in the production of the aqueous dispersion of the colored resin fine particles for an ink of the present invention is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate and n-butyl acrylate. Acrylates such as methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate and n-butyl methacrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, and salicylic acid One or more kinds are selected from hydrophobic monomers such as vinyl esters such as vinyl, olefins such as butadiene, isoprene and propylene, and styrenes such as styrene and methylstyrene, and are subjected to emulsion polymerization. In addition, a hydrophilic monomer having a hydrophilic functional group such as an amino group, a carboxyl group, a sulfone group, an amide group, or a hydroxyl group is preferably added within a range that does not impair emulsion polymerization, preferably within 50% by weight (based on the total amount of the vinyl monomer). )). Also, as a crosslinking agent,
A monomer having a reactive crosslinking group such as an epoxide group, a hydroxymethylamide group or an isocyanate group or a polyfunctional monomer having two or more vinyl groups may be blended.

The polymerizable surfactant used for producing the aqueous dispersion of colored resin fine particles for ink of the present invention is not particularly limited as long as it has a vinyl group and has a surface (interfacial) activity. The ionicity of cations, cations and nonions is not limited. For example, "Adekaria Soap NE-10", "NE-20", "NE-30", "NE-40", and "SE-10" manufactured by Asahi Denka Kogyo KK
N "," Latemul S-180 "manufactured by Kao Corporation," Same S
-180A "," S-120A "," Eleminol JS-2 "manufactured by Sanyo Chemical Industry Co., Ltd., and the like.
One type or a combination of two or more types is used. The amount of the polymerizable surfactant used is desirably 0.1 to 50% by weight based on the vinyl monomer.

The water-soluble dye used for producing the aqueous dispersion of the colored resin fine particles for ink of the present invention is, for example, "RHODAMINE 6GCP (CI, manufactured by Sumitomo Chemical Co., Ltd.)
BASIC RED 1) ”,“ Hodogaya Chemical Industry Co., Ltd. ”
"AIZEN CATHILON PINK FG"
H "(CI BASIC RED 13)" and "AIZEN VICTORIA P" manufactured by Hodogaya Chemical Industry Co., Ltd.
URE BLUE BOH ”(CI BASIC BL
UE 7) ”and“ AIZEN ERYTHROSINE ”manufactured by Hodogaya Chemical Industry Co., Ltd.
(CI ACIDRED 51) "and" AIZEN TARTTRAZINE CO.
NC "(CI ACID YELLOW 23)" and "DIREC manufactured by Hodogaya Chemical Industry Co., Ltd.
T SKY BLUE 5B "(CI DIRECT
BLUE 15) ”,“ D ”manufactured by Hodogaya Chemical Industry Co., Ltd.
IRECT FAST YELLOW GC "(CI
Direct dyes such as “DIRECT YELLOW44)”,
"DIACELLITONFAS manufactured by Mitsubishi Chemical Corporation"
T RUBINE 3B "(CI DISPERSE
RED 5) "," SUNIKA manufactured by Sumitomo Chemical Co., Ltd. "
RON TURQUAOISE BLUES-GL "(C
I DISPERSE BLUE 60) ". The amount of the dye is usually in the range of 0.2 to 50% by weight based on the vinyl resin fine particles (solid content) obtained by emulsion polymerization.

The ink composition for an ink jet recording apparatus of the present invention comprises a resin solid content of 2 obtained by the production method of the present invention.
An aqueous dispersion of colored resin fine particles for ink of 0 to 50% by weight is diluted with water and a water-soluble organic solvent to obtain a resin solid content of 3 to 5%.
It is prepared by adjusting to 30% by weight. The content of water is preferably from 30 to 90% by weight, more preferably from 40 to 60% by weight, based on the total amount of the ink composition. It can be obtained by appropriately adding a wetting agent, a pH adjusting agent, a preservative, and the like, if necessary.

The water-soluble organic solvent used in the ink composition of the present invention includes ethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 1,2-propanediol, 1,3-propanediol, 2-butanediol, 2,3-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2,5-hexanediol, 3-methyl 1,
3-butanediol, 2-methylpentane-2,4-diol, 3-methylpentane-1,3,5 triol,
Alkylene glycols such as 1,2,3-hexanetriol and glycerin; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; glycerols such as glycerol, diglycerol and triglycerol; ethylene glycol monomethyl ether; ethylene glycol monoethyl ether And lower alkyl ethers of glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, thiodiethanol, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidaridinone. Its content is 5% based on the total amount of the ink composition.
It is preferably from 80 to 80% by weight, more preferably from 10 to 60% by weight.

In addition, for example, methyl alcohol,
Ethyl alcohol, isopropyl alcohol, n-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, hexyl alcohol, octyl alcohol,
A water-soluble solvent such as alcohols such as nonyl alcohol, decyl alcohol and benzyl alcohol, amides such as dimethylformamide and diethylacetamide, and ketones such as acetone can also be mixed.

The thus obtained ink composition for an ink jet recording apparatus can obtain a clear image without causing the color of the printed portion to be turbid due to color mixing, and the image can be blurred by water or sweat. It does not disappear. Also,
A printed matter having excellent light fastness in which an image is not deteriorated even after long-term storage can be obtained. It is considered that such excellent characteristics are obtained due to the effect of the specific production method of the aqueous dispersion of the colored resin fine particles for ink according to the present invention.

The aqueous dispersion of colored resin fine particles for an ink according to the present invention has a low surface tension because it has almost no surface active substance in an aqueous medium as compared with a dispersion obtained using a conventional surfactant. High (usually 40d
yn / cm or more). Therefore, when used in an ink composition for an ink jet recording apparatus, a clear image can be obtained in which the printed portion does not bleed, and the water-resistant coating does not bleed or disappear due to water or sweat. Can be obtained.

The aqueous dispersion of colored resin fine particles for ink of the present invention does not usually aggregate or precipitate. When this aqueous dispersion of colored resin fine particles for ink is used in an ink composition for an ink jet recording device, the particle diameter of the colored resin fine particles for ink is 1.0 μm or less, so that the ink composition passes through a thin nozzle. High degree of stability is obtained without clogging.

The ink composition for an ink jet recording apparatus according to the present invention is capable of obtaining a clear image without causing the print portion to become turbid due to color mixing, and the image being blurred or lost by water or sweat. Nor. Further, a printed portion having excellent light fastness in which an image is not deteriorated even after long-term storage can be obtained. It is considered that such excellent characteristics are obtained due to the effect of the aqueous dispersion of the coloring resin fine particles for ink according to the present invention.

[0019]

The present invention will be described in more detail with reference to the following examples and comparative examples. The performance test in each case was performed according to the following method. (Bleeding) The degree of blurring of characters printed on PPC copy paper was visually determined. ：: no bleeding Δ: slight bleeding X: bleeding (water resistance) The character printed on PPC copy paper was immersed in water for 1 hour, and the degree of bleeding was visually determined. ：: no bleeding Δ: slight bleeding ×: bleeding (light resistance) The characters printed on PPC copy paper were irradiated with a fade meter, and the time during which fading was observed was measured. (Storage stability) The cartridge filled with the ink composition is placed in a thermostat at 50 ° C., and the number of days until printing becomes impossible is measured.

(Particle Size) The particle size of the colored resin fine particles in the ink composition was measured using a laser scattering type particle size distribution analyzer (Coulter Counter, Model N4SD, manufactured by Nikkiso Co., Ltd.). (Viscosity) The viscosity of the ink composition was measured using a cone plate type rotational viscometer [Tokyo Keiki Co., Ltd., EMD type]. The measurement temperature was 25 ° C. (Surface tension) The surface tension of the ink composition was measured by a hanging plate method. The measurement temperature was 25 ° C.

Example 1 A 2-liter flask was equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen gas inlet tube, and a 500-ml separatory funnel for charging monomers, set in a hot water tank, and charged 250 g of distilled water. The internal temperature is raised to 80 ° C. while introducing nitrogen gas. On the other hand, 500 g of a vinyl monomer mixture consisting of 250 g of methyl methacrylate, 200 g of n-butyl methacrylate, and 50 g of methacrylic acid was added to 25 g of distilled water.
In a mixed solution of 0 g and 10 g of a polymerizable surfactant [“Adecaria Soap SE-10N” manufactured by Asahi Denka Kogyo Co., Ltd.], a solution was prepared by further stirring and dissolving 1 g of ammonium persulfate. The prepared solution was poured into the separating funnel at a temperature of 8 ° C.
The mixture was added to the flask maintained at about 0 ° C. with stirring over 3 hours, and the polymerization was terminated at the 5th hour to obtain an aqueous dispersion of resin fine particles. To this aqueous dispersion, 500 g of distilled water,
Red dye [AIZEN C manufactured by Hodogaya Chemical Industry Co., Ltd.
ATHILON PINK FGH "] was added thereto, mixed uniformly, and then gradually heated to a temperature of 90 ° C. for 2 hours to obtain an aqueous dispersion of colored resin fine particles for an ink. After allowing the aqueous dispersion of the colored resin fine particles to cool naturally, 3000 g of distilled water and 500 g of propylene glycol were added, and the mixture was stirred uniformly to obtain a viscosity of 2.5 cP.
A red ink composition having a surface tension of 53 dyn / cm was obtained.
The particle diameter of the colored resin fine particles for ink in the red ink composition was 0.15 μm. Also, the red ink composition,
It has excellent water and light fastness properties and has a clear red color without bleeding or clogging.

Example 2 A 2 liter flask was equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen gas inlet tube, and a 500 ml separatory funnel for charging monomers, set in a hot water tank, and charged 250 g of distilled water. The internal temperature is raised to 80 ° C. while introducing nitrogen gas. On the other hand, styrene 200g, methacrylic acid n
-500 g of a monomer mixture consisting of 200 g of butyl and 100 g of acrylic acid is stirred and mixed in a mixed solution of 250 g of distilled water and 8 g of a polymerizable surfactant [“Latemul S-180” manufactured by Kao Corporation] A solution in which 2 g of ammonium persulfate was dissolved was prepared. This prepared solution was added to the flask maintained at a temperature of about 80 ° C. from the above separating funnel over 3 hours with stirring, and the polymerization was terminated at the 5th hour to obtain an aqueous dispersion of fine resin particles. To this aqueous dispersion, 500 g of distilled water and a blue dye [“AIZEN VICTORIA PURE” manufactured by Hodogaya Chemical Industry Co., Ltd.
BLUE BOH ″], and the mixture was stirred uniformly, then gradually heated, and heated at 95 ° C. for 2 hours to obtain an aqueous dispersion of coloring resin fine particles for ink. After the resin fine particle aqueous dispersion was allowed to cool naturally, 3000 g of distilled water and 500 g of propylene glycol were added thereto, and the mixture was stirred uniformly and had a viscosity of 2.8 cp and a surface tension of 56 d.
A blue ink composition of yn / cm was obtained. The particle diameter of the colored resin fine particles for ink in the blue ink composition is 0.20 μm
Met. Further, the blue ink composition had excellent properties of water resistance and light resistance, and exhibited a clear blue color without bleeding and clogging.

Comparative Example 1 25 of a water-soluble acrylic resin ["JONCRYL 61J" (solid content: 30%) manufactured by Johnson Polymer Co., Ltd.]
g, red dye [“AIZEN” manufactured by Hodogaya Chemical Industry Co., Ltd.
1 g of CATHILON PINK FGH "], 10 g of propylene glycol and 64 g of distilled water were mixed and stirred and dissolved for 1 hour to obtain a red ink composition.

Comparative Example 2 Blue dye [AIZEN V manufactured by Hodogaya Chemical Industry Co., Ltd.
ICTORIA PURE BLUE BOH "]
g, 10 g of propylene glycol and 89 g of distilled water were mixed and dissolved by stirring for 1 hour to obtain a blue ink composition.

Comparative Example 3 10 g of the polymerizable surfactant of Example 1 [Adecaria Soap SE-10N manufactured by Asahi Denka Kogyo Co., Ltd.] was added to 6 g of sodium dodecylbenzenesulfonate and polyoxyethylene nonylphenyl. A red ink composition was produced under the same conditions except that the surfactant was changed to 4 g of ether.
This red ink composition has a viscosity of 2.8 cp and a surface tension of 38.
dyn / cm. The particle diameter of the colored resin fine particles for ink in the ink composition was 0.23 μm.

Comparative Example 4 An ink composition was obtained under the same conditions as in Example 2 except that no heat treatment was performed.

[0027]

[Table 1]

[0028]

The method for producing the aqueous dispersion of colored resin fine particles for ink of the present invention is based on the aqueous dispersion of colored resin fine particles for ink having a sufficient concentration to be a stable base of the ink composition of the present invention without forming a precipitate. I will provide a. The ink composition of the present invention has excellent storage stability. Further, the ink jet recording using the ink composition of the present invention, the printed portion does not bleed,
Gives clear images and is excellent in water resistance and light resistance.

Claims (3)

[Claims] 1. A colored resin fine particle for ink, comprising: dissolving a water-soluble dye in an aqueous dispersion of fine resin particles obtained by emulsion-polymerizing a vinyl monomer using a polymerizable surfactant; A method for producing an aqueous dispersion. 2. A method for dissolving a water-soluble dye in an aqueous dispersion of resin fine particles obtained by emulsion-polymerizing a vinyl monomer using a polymerizable surfactant, and subjecting the aqueous dispersion to heat treatment to prepare an aqueous colored resin fine particle for ink. An ink composition for an ink jet recording apparatus containing a dispersion. 3. An aqueous dispersion of colored resin fine particles for ink comprising:
3. The ink composition for an ink jet recording apparatus according to claim 2, wherein the ink composition contains about 30% by weight (in terms of resin solid content).