JPH09157559A - Ink jet recording fluid and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jet recording fluid having good water resistance and good stability of ink delivery from a nozzle. SOLUTION: This ink jet recording fluid is prepared by dispersing an organic pigment having a mean particle diameter of 10-150nm and an average aspect ratio of 1:1 to 2:1 or colored particles prepared by coating the peripheries of resin particles having a mean particle diameter of 50-300nm with the above organic pigment in an aqueous liquid. The process for producing an ink jet recording fluid comprises mixing an organic pigment dispersion prepared by kneading an organic pigment, a water-soluble inorganic salt and a water-soluble solvent, dispersing the resulting mixture in water and removing the water-soluble inorganic salt and the water-soluble solvent from the dispersion with a dispersion of resin particles having a mean particle diameter of 50-300nm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording liquid having excellent water resistance and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, ink jet recording liquids have been disclosed in JP-A-53-61412 and JP-A-54-89.
As disclosed in Japanese Patent Publication No. 811 and Japanese Patent Laid-Open No. 55-65269, water-soluble dyes such as acid dyes, direct dyes and basic dyes dissolved in a glycol solvent and water are often used. However, as the water-soluble dye, those having high solubility in water are generally used in order to obtain stability of the recording liquid. Therefore, the ink jet recorded matter generally has poor water resistance, and there is a problem that spillage of water easily causes bleeding of the dye in the recorded portion.

In order to improve such poor water resistance,
As disclosed in JP-A-56-57862, attempts have been made to change the structure of the dye or to prepare a recording solution having a strong basicity. Further, JP-A-50-49004, JP-A-57-36692 and JP-A-59-2.
As disclosed in JP-A-0696 and JP-A-59-146889, attempts have been made to improve water resistance by making good use of the reaction between recording paper and recording liquid. Although these methods have a remarkable effect on a specific recording paper, they lack versatility in that they are restricted by the recording paper.
When a recording paper other than a specific recording paper is used, a recording liquid containing a water-soluble dye cannot often obtain sufficient water resistance of the recorded material.

As recording liquids having good water resistance, there are those in which an oil-soluble dye is dispersed or dissolved in a high boiling point solvent, and those in which an oil-soluble dye is dissolved in a volatile solvent. Environmentally disliked the emission of
Depending on the case where a large amount of data is recorded or where the apparatus is installed, the necessity of solvent recovery may be a problem. Therefore, in order to improve the water resistance of the recorded matter, a recording liquid in which a pigment is dispersed in an aqueous medium has been developed.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording liquid having good water resistance and good ejection stability at a nozzle.

[0006]

That is, according to the present invention, the average particle size is 10 to 150 nm, and the average ratio of length to width is 1 :.
There is provided an inkjet recording liquid comprising an organic pigment of 1 to 2: 1 dispersed in an aqueous liquid. Furthermore, the present invention provides the above-mentioned ink jet recording liquid, which comprises a resin and the weight ratio of the resin to the organic pigment is 1: 6 to 6: 1. Further, according to the present invention, the resin particles having an average particle size of 50 to 300 nm are surrounded by an average particle size of 10
Disclosed is an inkjet recording liquid comprising: colored particles covered with an organic pigment having an average length-to-width ratio of ˜150 nm and a length-to-width ratio of 1: 1 to 2: 1. Furthermore, in the present invention, the average particle size of the organic pigment is 10 to 7
The recording liquid for inkjet is characterized by having a thickness of 0 nm. Further, the present invention provides an organic pigment of 0.1 to
There is provided the above-mentioned ink jet recording liquid containing 10% by weight. Further, according to the present invention, the method for producing an inkjet recording liquid is characterized in that the organic pigment is kneaded with a water-soluble inorganic salt and a water-soluble solvent, dispersed in water, and then the water-soluble inorganic salt and the water-soluble solvent are removed. I will provide a. Further, in the present invention, an organic pigment is kneaded together with a water-soluble inorganic salt and a water-soluble solvent, dispersed in water, and then the water-soluble inorganic salt and the water-soluble solvent are removed to obtain an average particle size of 1
A dispersion liquid of organic pigment having an average length-to-width ratio of 50 nm or less and 1: 1 to 2: 1 and a dispersion liquid of resin particles having an average particle diameter of 50 to 300 nm are mixed and stirred. Provided is a method for manufacturing an inkjet recording liquid.

As shown in FIGS. 1 to 3, the organic pigment of the present invention has a shape approaching a sphere having an average length-to-width ratio of 1: 1 to 2: 1. By forming the organic pigment into a shape close to a sphere, it is possible to obtain an inkjet recording liquid that is excellent in dispersion stability, stability over time, fluidity in minute pipes, and jetting stability associated therewith. The organic pigment of the present invention has an average particle size of 10 to 150 nm, and the average primary particle size of the organic pigment measured using an electron microscope is 10 to 150 nm.
It is preferably 70 nm, more preferably 10 to 40 nm. If the average particle size is less than 10 nm, further improvement is required in production, and if it exceeds 150 nm, stable dispersion cannot be obtained and stability against sedimentation is insufficient.

The ink jet recording liquid of the present invention may contain a resin for firmly fixing the pigment. In that case, the weight ratio of resin to organic pigment is from 1: 6 to
By setting the ratio to 6: 1, it is possible to stabilize the organic pigment and improve the adhesion of the ink jet recording liquid to the printing medium and the water resistance. As the resin, acrylic, styrene-
Aqueous resins such as acrylic resins, polyester resins, polyamide resins, and polyurethane resins that dissolve or disperse in water can be used.

Examples of the water-based resin include alkyl esters, aryl esters, arylalkyl esters, styrene, α-methylstyrene, vinyltoluene, etc. of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, etc., and carboxyl groups. , Sulfonic acid groups, phosphoric acid ester groups, or their sodium salts, potassium salts,
Anionic hydrophilic groups such as primary, secondary or tertiary alkylamine salts and alkanolamine salts, cationic hydrophilic groups such as quaternary ammonium groups and pyridinium groups, or hydroxyl groups, carboxamide groups and polyethers. What is obtained by polymerizing monomers having a nonionic hydrophilic group such as a glycol group or an ether group by a usual method is used. These are used by adjusting the acid value to an appropriate value in the course of polymerization and adjusting the solubilization with amine, ammonia, alkali or the like.

In the ink jet recording liquid of the present invention, the resin and the organic pigment may form colored particles in which the periphery of the resin particle is covered with the organic pigment. The recording liquid for inkjet preferably contains the colored particles in an amount of 0.1 to 10% by weight. The weight ratio of the resin particles to the organic pigment is preferably 1: 6 to 6: 1. An ink jet recording liquid obtained by dispersing colored particles in which resin particles are covered with an organic pigment in an aqueous liquid has low viscosity, stable dispersibility, and stability in continuous jetting.

The resin particles forming the colored particles have an average particle size of 50 to 300 nm, preferably 50 to 200 nm, and include acrylic acid, methacrylic acid, itaconic acid,
Alkyl esters of unsaturated carboxylic acids such as maleic acid,
Aryl ester, arylalkyl ester, styrene, α-methylstyrene, vinyltoluene, etc., and carboxyl group, sulfonic acid group, phosphoric acid ester group, or their sodium salt, potassium salt, primary, secondary or tertiary Anionic hydrophilic groups such as alkylamine salts and alkanolamine salts, cation type hydrophilic groups such as quaternary ammonium groups and pyridinium groups, or hydroxyl groups,
It can be obtained by emulsion polymerization of a monomer having a nonionic hydrophilic group such as a carboxamide group, a polyether glycol group or an ether group by a usual method. If necessary, a neutralizing agent such as ammonia, amine or inorganic alkali can be appropriately adjusted and added to the ink jet recording liquid of the present invention.

The organic pigment is preferably at least one selected from the group consisting of quinacridone organic pigments, phthalocyanine organic pigments, azo organic pigments, isoindolinone organic pigments, quinophthalone organic pigments, and imidazolone organic pigments. Used for. Specific examples of organic pigments include insoluble azo pigments such as toluidine red, toluidine maroon, hansa yellow, benzidine yellow, and pyrazolone red, soluble azo pigments such as litol red, heliobordeaux, pigment scarlet, permanent red 2B, alizarin, and indantrone. , Derivatives from vat dyes such as thioindigo maroon, phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green, quinacridone pigments such as quinacridone red and quinacridone magenta, perylene pigments such as perylene red and perylene scarlet, isoindolinone ero , Isoindolinone-based pigments such as isoindolinone orange, benzimidazolone yellow, benzimidazolone orange, and benzimidazolone red Dazolone pigments, pyranthrone red, pyranthrone orange and other pyranthrone pigments, thioindigo pigments, condensed azo pigments, flavanthrone yellow, acylamide yellow, quinophthalone yellow, nickel azo yellow, copper azomethine yellow, perinone orange, anthron Other pigments such as orange, dianthraquinonyl red and dioxazine violet can be exemplified.

In addition, the organic pigment is a color index (C.
I.) Number, CI Pigment Yellow 12,
13, 14, 17, 20, 24, 74, 83, 869
3, 109, 110, 117, 120, 125, 13
7, 138, 147, 148, 151, 153, 15
4, 166, 168, CI Pigment Orange 16,3
6, 43, 51, 55, 59, 61, CI Pigment Red 9, 48, 49, 52, 53, 57, 97, 12
2,123,149,168,175,176,17
7, 180, 192, 215, 216, 217, 22
0,223,224,226,227,228,23
8, 240, CI Pigment Violet 19, 23,
29, 30, 37, 40, 50, CI Pigment Blue 15, 15: 1, 15: 4, 15: 6, 22, 60, 6
4, CI Pigment Green 7, 36, CI Pigment Brown 23, 25, 26 and the like.

In the ink jet recording liquid of the present invention, an organic pigment is finely dispersed in an aqueous liquid together with a compound of the following general formula and a dispersant, if necessary, so that the ratio of length to width is 1: 1. It is manufactured by mixing the mixture with an aqueous resin solution or a resin dispersion as needed, and stirring the mixture at a ratio of 2: 1. P- [X-Y-Z-N ( R 1) R 2 ] n (In the formula, P is an organic pigment residue, a heterocyclic residue or an aromatic polycyclic compound residue, X represents, S, C , N, O, H, a divalent linking group consisting of a chemically rational combination composed of 2 to 15 atoms, Y is a direct bond, -NR-
(However, R is H or an alkyl group having 1 to 18 carbon atoms),
A divalent linking group selected from —O—, Z is an alkylene group having 1 to 6 carbon atoms, R ¹ and R ² are each independently an optionally substituted alkyl group having 1 to 18 carbon atoms, or R ¹
And R ² may form a heterocycle, which may have a substituent, and n represents an integer of 1 to 3. )

As the dispersant, various surfactants, low molecular weight dispersants, resin-based dispersants having a hydrophilic functional group and a hydrophobic functional group, and the like are used. As the surfactant, anionic, nonionic, cationic or amphoteric surfactant can be used.

Examples of the anionic activator include fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfonates, alkylnaphthalene sulfonates, dialkyl sulfonates, dialkyl sulfosuccinates, alkyl diaryl ether disulfonates, alkyl phosphates. Salt, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkylaryl ether sulfate, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester salt, glycerol borate fatty acid ester, polyoxyethylene glycerol fatty acid ester, etc. It can be illustrated.

Examples of the nonionic activator include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, Examples thereof include glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, fluorine-based, and silicon-based nonionic activators.

Examples of the cationic activator include alkylamine salts, quaternary ammonium salts, alkylpyridinium salts and alkylimidazolium salts. Examples of amphoteric surfactants include alkyl betaines, alkylamine oxides, phosphadylcholines, and the like. As the low molecular weight dispersant, an alkyl group-substituted or unsubstituted naphthalene to which 5 to 20 alkylene oxides are added is a resin-based dispersant having a hydrophilic functional group and a hydrophobic functional group. Examples thereof include low molecular weight acrylic resin-based copolymers and oligomers.

The fine dispersion of organic pigment in an aqueous liquid is
It can be carried out by using a dispersing machine such as a sand mill, a ball mill, an attritor, a paint shaker, a pearl mill, or an ultrasonic dispersing machine, but the ratio of the length to the width of the organic pigment is 1 :.
In order to bring it closer to 1, the organic pigment is kneaded with a water-soluble inorganic salt, a water-soluble solvent and, if necessary, the compound of the following general formula, dispersed in water, and then the water-soluble inorganic salt and the water-soluble solvent are removed. It is preferable. In this method, the water-soluble inorganic salt is used as a crushing aid, and the elongated primary particles of the organic pigment are mechanically finely formed into a shape close to a sphere. Specifically, in a mixture of an organic pigment, a water-soluble inorganic salt and, if necessary, a compound of the following general formula, a small amount as a wetting agent (in weight ratio to the water-soluble inorganic salt)
1/20 to 1/2, preferably 1/20 to 1/3) of a water-soluble solvent is added, and the mixture is kneaded strongly with a kneader or the like, then poured into water and stirred with a high speed mixer to form a slurry. next,
The slurry is filtered and washed repeatedly to remove the water-soluble inorganic salt and water-soluble solvent.

P- [XYZN (R1) R2] n (wherein P is an organic dye residue, a heterocyclic residue or an aromatic polycyclic compound residue, and X is S , C, N, O, H is a divalent linking group composed of a chemically rational combination composed of 2 to 15 atoms, Y is a direct bond, -NR-
(However, R is H or an alkyl group having 1 to 18 carbon atoms),
A divalent linking group selected from —O—, Z is an alkylene group having 1 to 6 carbon atoms, R ¹ and R ² are each independently an optionally substituted alkyl group having 1 to 18 carbon atoms, or R ¹
And R ² may form a heterocycle, which may have a substituent, and n represents an integer of 1 to 3. )

Specifically, as X, --SO _2- , --C
_{O -, - CH 2 -,} - CH 2 S -, - CH 2 O -, - O
-, - COO -, - NH -, - CH 2 NHCOCH-,
Or, a combination of these may be mentioned. Among them, -SO
_{2 -, -CO -, - CH} 2 - is preferred. Also, R1
Examples of constituent elements other than carbon in the heterocyclic ring formed by R 2 and R 2 include N, O, and S. In addition, the substituent-[XY
Specific examples of -Z-N (R ¹ ) R ² ] n include the following.

[0022]

Embedded image

It should be noted that the organic pigment and P in the general formula compound, that is, the organic dye residue, the heterocyclic residue or the aromatic polycyclic compound residue, are of the same system in combination due to the usual hue relationship, Particularly, it is preferable to combine a phthalocyanine residue for a blue phthalocyanine pigment, a quinacridone residue for a red quinacridone pigment, and a benzimidazole residue for a yellow benzimidazole pigment, It does not necessarily have to match. Further, the compound of the above general formula is preferably partially soluble in a water-soluble solvent used as a wetting agent at the time of kneading, and when it is not soluble, a dilute acid is added to the general formula compound for neutralization treatment or the like. It is preferable to make it soluble. Acetic acid, hydrochloric acid, sulfuric acid or the like can be used as the acid. Further, the compounds of the above general formula can be used in combination of two or more kinds.

As the water-soluble inorganic salt, sodium chloride,
Examples thereof include potassium chloride. The water-soluble solvent is not particularly limited, but a solvent having a high boiling point is preferable from the viewpoint of safety, since the temperature rises during the kneading process and the solvent is easily evaporated. For example, 2- (methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol. , Triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl Ether, low molecular weight polypropylene glycol, etc. are used.

When the organic pigment is kneaded with the water-soluble inorganic salt, the water-soluble solvent and, if necessary, the compound of the above general formula, additives such as a dispersant and a plasticizer may be used together. Further, two or more kinds of organic pigments may be mixed and finely dispersed. The fine particles of the obtained organic pigment have a shape close to a rounded sphere as shown in FIGS. The organic pigment having such a shape is used as a slurry-like dispersion liquid which has not been subjected to a drying step after being thoroughly washed with water.

The ink jet recording liquid of the present invention comprises a dispersion liquid of an organic pigment, a sand mill, a homogenizer, a ball mill, an aqueous resin, water and a dispersant, if necessary.
A dispersion in a concentrated state is prepared in advance by well dispersing with a disperser such as a paint shaker or an ultrasonic disperser, and then a dispersion of resin particles having an average particle size of 50 to 300 nm, if necessary,
It can be produced by adding water and additives and mixing and stirring. The average particle size of the organic pigment dispersion is 50-
When mixed with a dispersion liquid of 300 nm resin particles and stirred, FIG.
As shown in (1), an ink jet recording liquid is obtained in which colored particles in which resin particles are covered with an organic pigment are dispersed in an aqueous liquid.

The mixing and stirring can be carried out by a mixing stirrer such as a high speed disperser or an emulsifier, in addition to a normal stirrer using a blade. The recording liquid for inkjet has a pore size of 1 μm or less, preferably 0.8 μm or less, and more preferably 0.
It is preferable to filter with a filter of 45 μm or less.
Prior to the filtration, the particles having a large particle size can be removed by centrifugation, whereby clogging in the filtration can be reduced and the service life of the filter can be prolonged.

The ink jet recording liquid of the present invention uses an aqueous liquid containing water and, if necessary, an aqueous solvent as a medium. As water, deionized water or distilled water from which metal ions have been removed is used. The aqueous solvent is used alone or in combination to prevent the recording liquid from drying at the nozzle portion and solidifying the recording liquid, and to prevent stable ejection of the recording liquid and drying of the nozzle over time. It can be used in the range of 50% by weight.

As the aqueous solvent, ethylene glycol,
Diethylene glycol, propylene glycol, triethylene glycol, polyethylene glycol, glycerin, tetraethylene glycol, dipropylene glycol, ketone alcohol, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether,
Examples include ethylene glycol monoethyl ether, 1,2-hexanediol, N-methyl-2-pyrrolidone, substituted pyrrolidone, 2,4,6-hexanetriol, tetrafurfuryl alcohol, and 4-methoxy-4-methylpentanone. .

Alcohols such as methanol, ethanol and isopropyl alcohol can also be used for the purpose of speeding up the drying of the recording liquid on paper. When the material to be printed with the recording liquid is a permeable material such as paper, a penetrant can be added in order to stop the permeation of the recording liquid into the paper and accelerate the apparent drying property. As the penetrant, glycol ethers such as diethylene glycol monobutyl ether exemplified as aqueous solvents, alkylene glycol, polyethylene glycol monolauryl ether, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium oleate, sodium dioctylsulfosuccinate and the like can be used. it can. These are sufficiently effective when used in an amount of 5% by weight or less of the recording liquid, and if the amount is larger than this, bleeding of printing and paper dropout (print through) occur, which is not preferable.

The recording liquid of the present invention may contain a fungicide in the range of 0.05 to 1.0% by weight of the recording liquid in order to prevent the occurrence of mold. Antifungal agents include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, zinc pyridinethione-1.
-Oxide, 1,2-benzisothiazolin-3-one, amine salt of 1-benzisothiazolin-3-one and the like are used.

A chelating agent may be used in the range of 0 to 0.5% by weight of the recording liquid in order to prevent metal deposition at the nozzle portion and insoluble matter in the recording liquid. . The chelating agent blocks metal ions in the recording liquid, and specifically includes ethylenediaminetetraacetic acid, sodium salt of ethylenediaminetetraacetic acid, diammonium salt of ethylenediaminetetraacetic acid, and ethylenediaminetetraacetic acid. Acid ammonium tetraammonium salt.

Further, in order to adjust the pH of the recording liquid and to stabilize the recording liquid or the stability with the recording liquid piping in the recording apparatus, a pH adjusting agent such as amine, inorganic salt, ammonia, etc., a buffer such as phosphoric acid, etc. A liquid can be used. Further, an antifoaming agent may be added in order to prevent the circulation and movement of the recording liquid or the generation of bubbles during the production of the recording liquid.

Further, for the purpose of adjusting the hue and imparting the density, the dye can be used in such a form that there is no problem in water resistance and light resistance. Since the dispersion stability of pigments may be deteriorated by the use of dyes, the amount used is 4
It is preferable to keep it at 0% by weight or less, and more preferably 25% by weight or less. As the dye, a water-insoluble dye such as a disperse dye or an oil-soluble dye, a dye in which a direct dye, an acid dye, a basic dye or the like is insolubilized by lake formation, a reactive dye, a metal-containing dye or the like is used. The dye is preferably a purified dye from which inorganic salts have been removed.

Other additives such as urea and dimethylurea may be added. The recording liquid is preferably prepared as a liquid having a viscosity of 0.8 to 15 cps (25 ° C.), though it depends on the type of recording device. Surface tension is 25-6
0 dyn / cm is preferable. The pH is not particularly limited, but it is in the range of 4 to 12, and when a glass nozzle is used, it is acidic to neutral of 4 to 7, and in a general nozzle it is 7
Neutral to weakly alkaline of 10 are preferred.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
Parts and% in the examples indicate parts by weight and% by weight. [Example 1] 220 parts of quinacridone red pigment ("Poster Palm Pink E" manufactured by Hoechst), 2200 parts of sodium chloride, 160 parts of polyethylene glycol ("Polyethylene glycol 300" manufactured by Tokyo Kasei) and 1 gallon kneader made of stainless steel (Inoue (Manufactured by Seisakusho), 6
Kneaded for hours. Next, this mixture was poured into 2.5 L of warm water and stirred at a high speed mixer for about 1 hour while being heated to about 80 ° C. to form a slurry. Filtration and washing with water were repeated 8 times to remove sodium chloride and polyethylene glycol to obtain an aqueous red pigment slurry I having a solid content of 40%. When the aqueous red pigment slurry I was observed with a scanning electron microscope, the pigment particles had a shape as shown in FIG. 1 and the ratio of length to width was within the range of 1: 1 to 1.5: 1.

The following raw materials were placed in a sand mill and dispersed for 2 hours to prepare a concentrated recording liquid for inkjet. Aqueous red pigment slurry I (solid content 50%) 50.0 parts Acrylic resin aqueous solution 3.0 parts ("John Cryl 62" manufactured by Johnson Polymer Co., solid content 31.0%) Dimethylaminoethanol 0.1 parts Nonionic Activator ("Emulgen A-90" manufactured by Kao Corporation) 1.0 part Purified water 50.0 parts Glycerin 6.0 parts

The following raw materials were mixed, filtered with a 1 μm membrane filter, and further filtered with a 0.45 μm membrane filter to prepare a recording liquid. When the obtained recording liquid was observed with a transmission electron microscope, it was in the form of dispersion as shown in FIG. When the recording liquid was observed with a scanning electron microscope, the ratio of the length to the width of the pigment particles was 1: 1.
It was in ~ 1.5: 1. Concentrated recording liquid for ink jet 13.5 parts Nonionic activator ("Emulgen A-90" manufactured by Kao Corporation) 0.2 part Acrylic resin emulsion 2.5 parts ("W-251" manufactured by Nippon Polymer Co., Ltd., solid content) 40%) Ethylene glycol 10.0 parts Antifungal agent ("Sodium omazine" manufactured by Ohrin Chemical Co., Ltd.) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.02 parts Purified water 63.53 parts

[Example 2] Crude copper phthalocyanine pigment ("Copper phthalocyanine" manufactured by Toyo Ink Mfg. Co., Ltd.) 250
Parts, 2500 parts of sodium chloride, blue pigment dispersant (P-
[CH ₂ NH (CH ₂ ) ₄ N (CH ₃ ) ₂ ] ₃ , 25 parts of P is a copper phthalocyanine residue, and polyethylene glycol (“Polyethylene glycol 30 manufactured by Tokyo Kasei KK”)
0 ") 160 parts were placed in a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho) and kneaded for 3 hours. Next, this mixture was poured into 2.5 L of warm water and stirred at a high speed mixer for about 1 hour while being heated to about 80 ° C. to form a slurry. Filtration and washing with water were repeated 5 times to remove sodium chloride and polyethylene glycol to obtain an aqueous blue pigment slurry II having a solid content of 50%. When the aqueous blue pigment slurry II was observed with a scanning electron microscope, the pigment particles had a shape as shown in FIG. 2, and the ratio of length to width was within the range of 1: 1 to 1.5: 1.

The following raw materials were placed in a sand mill and dispersed for 3 hours to prepare a concentrated recording liquid for inkjet. Aqueous blue pigment slurry II (solid content 50%) 30.0 parts Acrylic resin aqueous solution 3.0 parts ("John Cryl 61J" manufactured by Johnson Polymer Co., Ltd., solid content 31.0%) Nonionic activator (manufactured by Kao Corporation " Emulgen 420 ") 1.0 part Purified water 50.0 parts Glycerin 6.0 parts

The following raw materials were mixed, filtered with a 1 μm membrane filter, and further filtered with a 0.45 μm membrane filter to prepare a recording liquid. When the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length to the width of the pigment particles was within the range of 1: 1 to 1.5: 1. Concentrated recording liquid for ink jet 13.5 parts Non-ionic activator (“Emulgen 420” manufactured by Kao Corporation) 0.2 parts Acrylic resin emulsion 2.2 parts (“W-251” manufactured by Nippon Polymer Co., Ltd., solid content 40) %) Ethylene glycol 10.0 parts Antifungal agent ("Sodium omazine" manufactured by Ohrin Chemical Co., Ltd.) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.02 parts Purified water 63.53 parts

Example 3 Crude Copper Phthalocyanine Pigment 2
260 parts of benzimidazolone type yellow pigment (“Poster Palm Yellow H3G” manufactured by Hoechst) was used in place of 50 parts, and yellow pigment dispersant (P- [CH ₂ NH (CH ₂ ) ₄ N (C
H ₃ ) ₂ ] ₃ , and P are benzimidazole residues) 15 parts, and an ink jet recording liquid was obtained in the same manner as in Example 2. When the pigment slurry obtained during the production of the inkjet recording liquid was observed with a scanning electron microscope,
The length to width ratio of the pigment particles was in the range 1: 1 to 2.0: 1. Further, when the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length to the width of the pigment particles was 1:
It was in 1 to 2.0: 1.

[Example 4] Crude copper phthalocyanine pigment ("Copper phthalocyanine" manufactured by Toyo Ink Mfg. Co., Ltd.) 250
Parts, 900 parts of sodium chloride, blue pigment dispersant (P-
_{[CH 2 NH (CH 2) 4} N (CH3) 2 ] _3, P is a copper phthalocyanine residue) 25 parts of acrylic oligomer (manufactured by Johnson Wax, Inc. "Joncryl 682") 100
Section and diethylene glycol (manufactured by Tokyo Kasei) 160
Parts were placed in the same kneader as in Example 1 and kneaded for 2 hours. Then, an aqueous blue pigment slurry IV having a solid content of 50% was obtained in the same manner as in Example 1. When the aqueous blue pigment slurry IV was observed with a scanning electron microscope, the length-width ratio of the pigment particles was within the range of 1: 1 to 1.5: 1.

The following raw materials were placed in a sand mill and dispersed for 4 hours to prepare a concentrated recording liquid for inkjet. Aqueous blue pigment slurry IV (solid content 50%) 30.0 parts Acrylic resin emulsion 2.3 parts (Nippon Polymer Co., Ltd. "F-157" solid content 40%) Dispersant (Zeneca "Solspers 27000") 5 parts Purified water 74.0 parts Glycerin 5.8 parts Dimethylethanolamine 0.1 parts

The following raw materials were mixed, filtered with a 3 μm membrane filter, subsequently filtered with a 1 μm membrane filter, and subsequently filtered with a 0.45 μm membrane filter to prepare a recording liquid. When the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length of the pigment particles to the width was within the range of 1: 1 to 1.5: 1. The above concentrated recording liquid for inkjet 13.7 parts Nonionic activator ("Emulgen 420" manufactured by Kao Corporation) 0.2 part Acrylic resin emulsion 2.2 parts ("W-251" manufactured by Nippon Polymer Co., Ltd., solid content 40) %) Diethylene glycol 9.0 parts Antifungal agent ("Sodium omazine" manufactured by Ohrin Chemical Co., Ltd.) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.03 parts Purified water 63.50 parts

[Example 5] 250 parts of quinacridone red pigment ("Poster Palm Pink E" manufactured by Hoechst), 2500 parts of sodium chloride, polyethylene glycol ("Polyethylene glycol 300" manufactured by Tokyo Kasei) 160
The part was put into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho) and kneaded for 3 hours. Then 2.5 L of this mixture
It is poured into warm water of about 80 ° C. and stirred for about 1 hour with a high speed mixer to form a slurry, and filtration and washing with water are repeated 5 times to remove sodium chloride and polyethylene glycol, and a solid content of 50%. Aqueous red pigment slurry V was obtained. When the aqueous red pigment slurry V was observed with a scanning electron microscope, the ratio of the length to the width of the pigment particles was found to be
It was in 1: 1 to 1.5: 1.

The following raw materials were placed in a sand mill and dispersed for 4 hours to prepare a concentrated recording liquid for inkjet. Aqueous red pigment slurry V (solid content 50%) 30.0 parts Acrylic resin aqueous solution 3.0 parts ("John Cryl 62" manufactured by Johnson Polymer Co., Ltd., solid content 31.0%) Nonionic activator (manufactured by Kao Corporation " Emulgen A-90 ") 1.0 part Purified water 50.0 parts Glycerin 6.0 parts

The following raw materials were mixed and then filtered through a 0.45 μm membrane filter to prepare a recording liquid. When the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length of the pigment particles to the width was within the range of 1: 1 to 1.5: 1. Concentrated recording liquid for ink jet 13.5 parts Nonionic activator ("Emulgen A-90" manufactured by Kao) 0.2 parts Acrylic resin emulsion 2.4 parts ("W-251" manufactured by Nippon Polymer Co., Ltd., solid content) 40%) Ethylene glycol 10.0 parts Antifungal agent ("Proxel GXL" manufactured by Zeneca) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.02 parts Purified water 63.53 parts

Comparative Example 1 The following raw materials were placed in a paint shaker and dispersed for 9 hours to prepare a concentrated recording liquid for inkjet. When the concentrated recording liquid for inkjet was observed with a scanning electron microscope, the pigment particles had a shape as shown in FIG. 4, and the ratio of length to width was 3: 1 or more. Quinacridone red pigment 15.0 parts ("Poster Palm Pink E" manufactured by Hoechst) Aqueous acrylic resin solution 3.0 parts ("John Cryl 62" manufactured by Johnson Polymer, solid content 31.0%) Nonionic activator ( "Emulgen A-90" manufactured by Kao Corporation) 1.0 part Purified water 50.0 parts Glycerin 6.0 parts

The following raw materials were mixed and then filtered through a 1 μm membrane filter to prepare a recording liquid. 1 μm
The filtration amount with the membrane filter of No. 1 was less than 1/3 of that of the example. Further, it was very difficult to filter with a 0.45 μm filter. When the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length of the pigment particles to the width was outside the range of 1: 1 to 2: 1. Concentrated recording liquid for ink jet 13.5 parts Nonionic activator (“Emulgen A-90” manufactured by Kao Corporation) 0.2 part Acrylic resin aqueous solution 2.3 parts (“John Krill 62” manufactured by Johnson Polymer Co., Ltd., solid content) 31.0%) Ethylene glycol 10.0 parts Antifungal agent ("Proxel GXL" manufactured by Zeneca) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.02 parts Purified water 63.53 parts

Example 6 In the same manner as in Example 3, except that 260 parts of the benzimidazolone yellow pigment was used, 280 parts of an azo yellow pigment (“Hansa Brilliant Yellow 9GX” manufactured by Hoechst Co., Ltd.) was used. % Aqueous yellow pigment slurry VI was obtained. When the aqueous yellow pigment slurry VI was observed with a transmission electron microscope, the pigment particles had a shape as shown in FIG. 3, and the ratio of length to width was in the range of 1: 1 to 1.8: 1. Next, the following raw materials were put into a sand mill and dispersed for 1 hour to prepare a concentrated recording liquid for inkjet. Aqueous yellow pigment slurry VI (solid content 50%) 55.0 parts Acrylic resin aqueous solution 7.0 parts ("John Cryl 61J" manufactured by Johnson Polymer Co., Ltd., solid content 31.0%) Nonionic activator (manufactured by Kao Corporation " Emulgen A-90 ") 4.0 parts Purified water 56.0 parts Diethylene glycol monobutyl ether 3.0 parts N-methyl-2-pyrrolidone 3.0 parts 2,4,7,9-tetramethyl-5-decyne-4 , 7-diol 1.0 part Ethylene glycol 1.0 part

The following raw materials were mixed, filtered with a 1 μm membrane filter, and then filtered with a 0.45 μm membrane filter to prepare a recording liquid. When the obtained recording liquid was observed with a transmission electron microscope, the ratio of the length to the width of the pigment particles was within the range of 1: 1 to 1.8: 1. Concentrated recording liquid for inkjet 13.0 parts Dispersant (“Solspers 27000” manufactured by Zeneca) 0.2 parts Acrylic resin emulsion 3.0 parts (“Emapoly TYN-40” manufactured by Gifu Shellac Manufacturing Co., solid content 44.8) %) Diethylaminoethanol 0.2 parts Diethylene glycol 22.5 parts Antifungal agent ("Proxel GXL" manufactured by Zeneca) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.02 parts Purified water 63.53 parts 2,4,4 7,9-Tetramethyl-5-decyne-4,7-diol 0.1 part

Example 7 Crude Copper Phthalocyanine Pigment 2
Phthalocyanine-based blue pigment (“Rionol Blue KLH-T” manufactured by Toyo Ink Mfg. Co., Ltd.) 280 instead of 50 parts
Was used in the same manner as in Example 4 to obtain an aqueous blue pigment slurry VII having a solid content of 50%. When the aqueous blue pigment slurry VII was observed with a scanning electron microscope, the length-width ratio of the pigment particles was within the range of 1: 1 to 1.5: 1. Next, the following raw materials were put into a sand mill and dispersed for 3 hours to prepare a concentrated recording liquid for inkjet. Aqueous blue pigment slurry VII (solid content 50%) 18.0 parts Acrylic resin aqueous solution 3.8 parts ("John Cryl 62" manufactured by Johnson Polymer Co., Ltd., solid content 31.0%) Nonionic activator (manufactured by Kao Corporation " Emulgen A-90 ") 3.0 parts Purified water 74.5 parts Ethylene glycol 6.0 parts

The following raw materials were mixed and then filtered through a 1 μm membrane filter and then through a 0.45 μm membrane filter to prepare a recording liquid. When the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length to the width of the pigment particles was within the range of 1: 1 to 1.5: 1. Concentrated recording liquid for ink jet 13.9 parts Dispersant ("Solspers 27000" manufactured by Zeneca) 0.3 part Acrylic resin emulsion 2.1 parts ("W-251" manufactured by Nippon Polymer Co., Ltd., solid content 40%) Glycerin 24 .0 part Antifungal agent ("Sodium Omazine" manufactured by Ohrin Chemical Co., Ltd.) 0.15 part Purified water 63.50 parts

Comparative Example 2 The following raw materials were placed in a sand mill and dispersed for 2 hours to prepare a concentrated recording liquid for inkjet. Phthalocyanine-based blue pigment (Toyo Ink Mfg. Co., Ltd., 8.0 parts "Rionol Blue KLH-T", pigment particle length to width ratio 4: 1) Acrylic resin aqueous solution 3.8 parts (Johnson Polymer's "John Kuril 62 ", solid content 31.0%) Dispersant (" Solspers 27000 "manufactured by Zeneca) 4.0 parts Purified water 82.5 parts Ethylene glycol 6.0 parts

The following raw materials were mixed and then filtered through a 1 μm membrane filter to prepare a recording liquid, but a filter three times as large as that in the example was used. Further, it was very difficult to filter with a 0.45 μm membrane filter.
When the obtained recording liquid was observed with a scanning electron microscope,
The length to width ratio of the pigment particles was 4: 1. Concentrated recording liquid for ink jet 13.9 parts Dispersant ("Solspers 27000" manufactured by Zeneca) 0.3 part Acrylic resin emulsion 2.1 parts ("W-251" manufactured by Nippon Polymer Co., Ltd., solid content 40%) Glycerin 24 .0 part Antifungal agent (Ohlin Chemical Co., Ltd. "Sodium Omazine") 0.15 part

Example 8 The following raw materials were placed in a pearl mill and dispersed for 3 hours to prepare a concentrated recording liquid for inkjet. Azo yellow pigment 25.0 parts ("Rionol Yellow FG1310" manufactured by Toyo Ink Mfg. Co., Ltd.) Dispersant ("Solspers 27000" manufactured by Zeneca) 0.3 parts Acrylic resin aqueous solution 3.0 parts ("John" manufactured by Johnson Polymer Co., Ltd.) Kuril 62 ", solid content 31.0%) Dimethylaminoethanol 0.1 part Nonionic activator (" Emulgen A-90 "manufactured by Kao Co., Ltd.) 1.3 parts Purified water 75.0 parts Ethylene glycol 6.0 parts

The following raw materials were mixed, filtered with a membrane filter of 1 μm, and then filtered with a membrane filter of 0.45 μm to prepare a recording liquid. When the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length of the pigment particles to the width was within the range of 1: 1 to 2.0: 1. Concentrated recording liquid for ink jet 13.5 parts Nonionic activator ("Emulgen A-90" manufactured by Kao Corporation) 0.2 part Acrylic resin emulsion 2.5 parts ("W-251" manufactured by Nippon Polymer Co., Ltd., solid content) 40%) Ethylene glycol 10.0 parts Antifungal agent ("Sodium omazine" manufactured by Ohrin Chemical Co., Ltd.) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.02 parts Purified water 63.53 parts

[Example 9] Crude copper phthalocyanine pigment ("Copper phthalocyanine" manufactured by Toyo Ink Mfg. Co., Ltd.) 250
Part, 2500 parts of sodium chloride and polyethylene glycol (“Polyethylene glycol 30 manufactured by Tokyo Kasei Co., Ltd.
0 ") 160 parts were placed in a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho) and kneaded for 3 hours. Next, this mixture was poured into 2.5 L of warm water and stirred at a high speed mixer for about 1 hour while being heated to about 80 ° C. to form a slurry. Filtration and washing with water were repeated 5 times to remove sodium chloride and polyethylene glycol to obtain an aqueous blue pigment slurry IX having a solid content of 50%. When the aqueous blue pigment slurry IX was observed with a scanning electron microscope, the ratio of the length to the width of the pigment particles was within the range of 1: 1 to 1.5: 1.

The following raw materials were placed in a pearl mill and dispersed for 3 hours to prepare a concentrated recording liquid for inkjet. Aqueous blue pigment slurry IX (50% solids) 30.0 parts blue pigment dispersing agent (P- _{[CH 2 NH (CH 2) 4} N (CH 3) 2 ] _3, P is a copper phthalocyanine residue) 1.4 Parts Dispersant ("Sensperth 27000" manufactured by Zeneca) 0.3 parts Acrylic resin aqueous solution 3.0 parts ("John Cryl 61J" manufactured by Johnson Polymer Co., solid content 31.0%) Nonionic activator (manufactured by Kao Corporation) "Emulgen 420") 1.0 part Purified water 50.0 parts Glycerin 6.0 parts

The following raw materials were mixed, filtered with a 1 μm membrane filter, and further filtered with a 0.45 μm membrane filter to prepare a recording liquid. When the obtained recording liquid was observed with a scanning electron microscope, the ratio of the length to the width of the pigment particles was within the range of 1: 1 to 1.5: 1. Concentrated recording liquid for ink jet 13.5 parts Nonionic activator ("Emulgen 420" manufactured by Kao Corporation) 0.2 part Acrylic resin emulsion 2.4 parts ("W-251" manufactured by Nippon Polymer Co., Ltd., solid content 40) %) Ethylene glycol 10.0 parts Antifungal agent ("Sodium Omazine" manufactured by Ohrin Chemical Co., Ltd.) 0.13 parts Ethylenediaminetetraacetic acid sodium salt 0.04 parts Purified water 63.33 parts

The recording liquids obtained in Examples and Comparative Examples were evaluated for filterability, viscosity, average particle size, printing condition, water resistance, transparency and jetting property. Table 1 shows the results. In addition,
The evaluation was performed as follows. The recording liquids obtained in Examples were naturally dissolved after being stored at -40 ° C for one week, but the initial viscosity was maintained and stable jetting characteristics were exhibited. Further, the recording liquid obtained in the example was stored in a constant temperature bath at 60 ° C. for 1 month, but the initial viscosity was maintained and stable ejection characteristics were exhibited.

[Filtration] 0.4 mm with a diameter of 90 mm per minute
The amount that could be filtered with a 5 μm membrane filter was measured. [Viscosity] Viscometer ("Viscomate VM-1" manufactured by Yamaichi Denki Co., Ltd.
A)) at 25 ° C. [Average Particle Size] The particle size distribution of the recording liquid was measured by a laser diffraction type particle size distribution meter (“DSL-700” manufactured by Otsuka Electronics Co., Ltd.) to determine the average particle size.

[Printing State] The recording liquid was put in a cartridge of an ink jet printer (“HG5130” manufactured by Seiko Epson Co., Ltd.) to record on plain paper (“K” manufactured by Xerox Co., Ltd.), and the printed state of the recorded matter was visually evaluated. . Good: No missing dots, no disturbance in direction. Defective: Missing dots and irregular orientation. [Water resistance] The recorded matter recorded on plain paper (“K” manufactured by Xerox) was dried, and then the presence or absence of ink bleeding and running when immersed in water for 1 minute was visually evaluated. Good: No ink bleeding or bleeding. Defective: There is ink bleeding and bleeding.

[Transparency] The transparency when the ink was spread on the inkjet OHP sheet with an applicator of 1.5 mil was visually evaluated. Good: There is transparency. Bad: No transparency. [Ejection characteristics] The ejection state of the nozzle during continuous printing was evaluated by the recorded matter. Good: Continuous printing was accurately performed at a predetermined position. Defective: Despite continuous printing, a defect occurs on the way, or printing is not performed at a predetermined position. [Resin Average Particle Size] The particle size distribution of the resin emulsion is measured by a laser diffraction particle size distribution meter (“DSL-70” manufactured by Otsuka Electronics Co.
0 ") to determine the average particle size. [Pigment average particle size] The pigment particles in the organic pigment slurry (concentrated recording liquid for Example 8 and Comparative Example) were observed with an electron microscope to determine the average particle size.

[0066]

[Table 1]

[0067]

According to the present invention, it is possible to obtain a recording liquid which gives a recorded product having good water resistance while using water as a medium. As a result, the restrictions on the recording medium are greatly reduced, and the application can be expanded to fields where water resistance was often insufficient due to the influence of the recording medium. Specifically, the ink jet recording liquid of the present invention can be used in fields such as office document preparation, cardboard marking, numbering, and bar code recording.

[0068]

[Brief description of the drawings]

FIG. 1 is an electron micrograph of organic pigment particles of Example 1 of the present invention.

FIG. 2 is an electron micrograph of organic pigment particles of Example 2 of the present invention.

FIG. 3 is an electron micrograph of organic pigment particles of Example 6 of the present invention.

FIG. 4 is an electron micrograph of organic pigment particles of Comparative Example 1 of the present invention.

FIG. 5 is an electron micrograph of the recording liquid of Example 1 of the invention.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yasuharu Iida 2-33-1 Kyobashi, Chuo-ku, Tokyo Within Toyo Inki Manufacturing Co., Ltd. Toyo Ink Manufacturing Co., Ltd. (72) Inventor Ichiro Toyota, 3-13 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd. (72) Inventor Akio Sato 2-3-3, Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd.

Claims (7)

[Claims] 1. An ink jet recording liquid comprising an organic pigment having an average particle diameter of 10 to 150 nm and an average length to width ratio of 1: 1 to 2: 1 dispersed in an aqueous liquid. . 2. The ink jet recording liquid according to claim 1, comprising a resin, and the weight ratio of the resin to the organic pigment is 1: 6 to 6: 1. 3. Coloring in which an organic pigment having an average particle size of 10 to 150 nm and an average length-to-width ratio of 1: 1 to 2: 1 covers the periphery of resin particles having an average particle size of 50 to 300 nm. An ink jet recording liquid comprising particles dispersed in an aqueous liquid. 4. The ink jet recording liquid according to claim 1, wherein the organic pigment has an average particle diameter of 10 to 70 nm. 5. The ink jet recording liquid according to claim 1, which contains an organic pigment in an amount of 0.1 to 10% by weight. 6. The ink jet recording according to claim 1, wherein the organic pigment is kneaded with a water-soluble inorganic salt and a water-soluble solvent and dispersed in water, and then the water-soluble inorganic salt and the water-soluble solvent are removed. Liquid manufacturing method. 7. An organic pigment is kneaded together with a water-soluble inorganic salt and a water-soluble solvent and dispersed in water, and then the water-soluble inorganic salt and the water-soluble solvent are removed to obtain an average particle diameter of 150 nm or less, and a length-to-width ratio. 4. The inkjet recording according to claim 3, wherein the dispersion liquid of the organic pigment having an average ratio of 1: 1 to 2: 1 and the dispersion liquid of the resin particles having an average particle diameter of 50 to 300 nm are mixed and stirred. Liquid manufacturing method.