JPH08269310A - Colored fine particle water dispersion - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an aqueous dispersion of a colored resin, which is capable of high-quality image recording and printing, and which is useful as a recording agent that achieves both high reliability and storage stability. [Structure] A hydrophobic dye, preferably an ionic group-containing polyester resin, and a hydrophilic solvent are mixed and dissolved, and water is added to emulsify the mixture, followed by desolvation to obtain colored polyester fine particles. Separately prepared unsaturated polyester fine particles aqueous dispersion, a cross-linking agent and an electrolyte are added and the temperature is raised to cause coagulation at the same time as cross-linking,
Obtain dendritic particles. In addition, non-spherical particles having an irregular shape and a flat shape are prepared. The colored polyester particles and non-spherical particles are blended to obtain the aqueous dispersion of the present invention. The water dispersion of the present invention can be used as a high-quality recording agent with little bleeding on plain paper.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a paint, a water-based paint,
The present invention relates to an aqueous dispersion of a resin that is widely used for paper coating agents, coating materials for films, etc. to recording materials, and in particular, from writing instruments, markers, marking pens, etc., to various printing machines, inkjets. The present invention relates to an aqueous dispersion of a colored polyester resin which can be suitably used as an ink recording material used in printers, ferroelectric printers and the like.

[0002]

2. Description of the Related Art In recent years, countermeasures against environmental problems have been required in all fields, and recording materials and inking materials used in printers, printing machines, markers, writing instruments, etc. are also desolvated.
It is required to be water-based. As an aqueous recording material, a material mainly composed of an aqueous solution of a water-soluble dye and a material mainly composed of a fine dispersion of a pigment are widely used.

Recording materials using water-soluble dyes are mainly aqueous dyes of water-soluble dyes classified into acid dyes, direct dyes, some food dyes, etc., glycols, alkanolamines, surface tension as moisturizers. Those in which a surfactant, alcohols, a resin component as a binder component and the like for the preparation of the above are added are used. Recording materials using these water-soluble dyes are most commonly used because of their high reliability against clogging in the writing tip or in the recording system. However, since the recording material using such a water-soluble dye is an aqueous solution of the dye, it easily bleeds on the recording paper. Further, since it is prepared so as to quickly penetrate into the recording paper in order to increase the apparent drying speed, it is unavoidable that the recording quality is deteriorated due to the blurring of the ink. It is also obvious that the water resistance is poor because it is a water-soluble dye. Furthermore, it is difficult to say that a water-soluble dye that has simply penetrated into recording paper and that has been dry-fixed is "dyed", and the light fastness is very low.

As a measure for solving the problems of the recording material using the water-soluble dye as described above, addition of resin fine particles such as emulsion and latex has been studied for a long time. Japanese Patent Application Laid-Open No. 55-18418 describes that "components such as rubber and resin are finely divided by an emulsifier (particle size of about 0.01 to
There is a proposal regarding a recording material for inkjet recording to which a latex which is a kind of colloidal solution dispersed in water in the form of several μm) is added. The latex preferably used is styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, polychloroprene latex, vinylpyridine-styrene-butadiene latex, butyl rubber latex, polybutadiene latex, polyisoprene latex, polysulfide rubber latex, etc. And synthetic resin latexes such as acrylic ester latex, styrene-butadiene resin latex, vinyl acetate latex, vinyl chloride latex, vinylidene chloride latex, and the like.

According to the proposal, the particle size of the latex particles that can be added is in the range of about 0.01 to several μm. However, if the particle size is less than 0.2 μm, the effect of preventing ink smearing on the recording paper is insufficient, and high recording quality cannot be obtained. The particle size is 1.0
If it is more than μm, the nozzle is frequently clogged and it becomes difficult to use it from the viewpoint of reliability. Therefore, it is considered that the practically usable range is approximately 0.2 to 1.0 μm. When such resin fine particles are added to the ink, attention must be paid to sedimentation or floating due to the difference in specific gravity between the particles and the medium. In the case of water-based ink, it is difficult for the specific gravity of the medium to deviate significantly from 1.0. In fine particles of about 0.2 μm or larger, the effect of gravity is larger than the diffusing force of particles due to Brownian motion, and therefore the difference between the particle specific gravity and the medium specific gravity is 0.1 in this region.
Hereafter, it is necessary to suppress it to preferably about 0.07 or less.

The specific gravity of the synthetic rubber-based latex exemplified in the patent proposal is in the range of about 0.9 to 1.0, and although such a condition is satisfied to some extent, most synthetic rubbers have unsaturated double bonds in the molecule. There is a problem in terms of light resistance and weather resistance. Further, when vulcanization is carried out to reduce unsaturated bonds, the fixing of particles onto recording paper is hindered, resulting in a problem in recording quality.
Further excessive vulcanization causes a specific gravity of 1.1 or more, which causes a problem of sedimentation. Furthermore, since such synthetic rubber latex has a low glass transition temperature, it is easy to form a film at room temperature, the nozzle is likely to be clogged when dried at the tip of an inkjet nozzle, and the dried product is soft and slightly sticky. Because it has, it is very difficult to remove. With respect to the synthetic resin latex exemplified in the patent, the specific gravity is 1.1 or more, and particularly in the case of a synthetic resin containing a halogen element, the specific gravity reaches 1.3 to 1.5. Sedimentation occurs in all areas. Furthermore, as can be said for all of these latexes, many of the emulsifiers used in the production of the latex are apt to promote foaming of the ink and lower the surface tension more than necessary, which is problematic.

Japanese Patent Application Laid-Open No. 54-146109 proposes a recording material using a water-soluble dye to which fine vinyl polymer particles swelled with a solvent and colored with an oily dye are added. Polymers preferably used are mainly (meth) acrylic acid ester-based copolymer fine particles, and it is described that a glass transition temperature of 30 ° C. or lower is a suitable condition. There is no description about the particle size in the proposal. It is obvious that fine particles swollen with a solvent at such a low glass transition temperature have film-forming properties when dried at room temperature, and when such an ink is used, nozzle clogging may frequently occur. It is easily analogized.

(Recording Material Using Pigment Dispersion) In order to improve the drawbacks of a recording material using a water-soluble dye, it has been proposed to use carbon black or an organic pigment as a recording material. In the recording material using such a pigment dispersion, the water resistance of the ink is greatly improved. However, these pigments have a high specific gravity of 1.5 to 2.0, and attention must be paid to the sedimentation of dispersed particles. In order to stably disperse the pigment having such a high specific gravity, the average particle diameter is about 0.
It is necessary to finely disperse the ink to 1 μm or less, resulting in a high dispersion cost and a very expensive ink. Further 0.1μ
If the particle size is less than m, the effect of preventing blurring is insufficient and high quality recorded characters and images cannot be obtained. Further, there is a problem that the physical properties of the ink such as surface tension and foaming property are limited by the dispersant used for dispersion.

(Recording Material Using Colored Resin Particles) An ink jet recording ink has been proposed for coloring a water-dispersible resin with an oil-soluble dye or a hydrophobic dye.
These are proposals relating to "ink using colored polymer particles as a recording agent". For example, JP-A-54-
58504 proposes an ink in which a mixture of a hydrophobic dye solution and vinyl polymer fine particles is oil-in-water dispersed. It is disclosed in the text that the vinyl polymer fine particles are swelled in the solvent of the dye solution by being mixed with the hydrophobic dye solution and further colored by the dye. Since the hydrophobic dye is used as the recording agent, the obtained image is said to have water resistance. According to the proposal, water is used as a continuous phase, and colored vinyl polymer particles swollen with a solvent are used as a dispersed phase so that water has control of ink viscosity and has a somewhat high viscosity (low volatility) as a solvent. It is allowed to use things. JP-A-55-13947
1, JP-A-3-250069 proposes an ink using emulsion-polymerized or dispersion-polymerized particles dyed with a dye. The purpose of the proposal is to prevent bleeding by using colored particles as a dispersoid and water (transparent) as a medium, as in Japanese Patent Laid-Open No. 54-58504. It is necessary to fix it on the recording paper by forming a film. It has been suggested that the desirable particle size is in the submicron region from the viewpoint of the necessity of film formation and ensuring of dispersion stability.

In both of the proposals, the water-dispersible resin is a vinyl polymer. In these vinyl polymers, it is difficult to perform high-concentration coloring because the dye has a low solubility in the resin. In Japanese Patent Laid-Open No. 54-58504, it is accepted that the polymer fine particles are swollen with a solvent to improve the dyeing property. In this case, however, there is a problem of nozzle clogging due to dry film formation at the nozzle tip. Occurs. Japanese Patent Laid-Open No. 4-
In 185672, in the ink composed of colored resin particles and an aqueous medium, a water-soluble compound is dissolved in the aqueous medium so that the specific gravity difference between the colored resin particles and the aqueous medium becomes 0.0
It is proposed that the particle size be 4 or less to prevent the sedimentation of particles. Here, it is said that inorganic salts are preferably used as the water-soluble compound. However, when such an inorganic salt is dissolved in an aqueous medium, the ionic strength in the system increases and the stability of the dispersion system decreases, so that the colored resin particles agglomerate and the fluid properties of the inkjet ink cannot be maintained.

JP-A-4-185673, JP-A-4-18
In 5674, the effective specific gravity is lowered by swelling the colored resin particles with a solvent in the ink composed of the colored resin particles and the aqueous medium, and the specific gravity difference between the colored resin particles and the aqueous medium is 0.04 or less. Is proposed. In such a case, it is difficult to avoid nozzle clogging as described above. As mentioned above, the recording materials mainly used for inkjet recording have been mainly reviewed.
Particle settling and clogging due to dry film formation are caused by writing instruments, markers, marking pens, other types of printers,
It also occurs when such an aqueous recording material is used in a printing machine.

The present inventors have conducted extensive studies in view of such circumstances, and as a result, have found that an aqueous dispersion of a polyester resin can be colored with an oily or hydrophobic dye at an extremely high concentration, and an aqueous dispersion of such colored polyester resin fine particles is found. It was proposed to use as an ink for writing instruments or a recording material for various printers. The recording material using such colored polyester fine particles has good recording quality on recording paper,
Moreover, although the dried film-forming product has characteristics such as excellent water resistance, the recording quality is not sufficient when recording is performed on textiles such as non-woven fabrics, waste cloths, cloths and knits. This is because the fiber density of such a fiber structure is coarser than that of recording paper. In addition, there are cases in which the recording quality is unsatisfactory even for cardboard, recycled paper, etc. of poor paper quality. It is easily inferred that the recording quality will be improved by increasing the particle size. However, in that case, similarly to the pigment-dispersed recording agent, it is easily inferred that a problem occurs due to sedimentation of particles.

[0013]

As described above, the fine particle dispersion type recording material using pigments, colored resin particles and the like overcomes the problems of the water-soluble dye type recording material and has a high recording quality. Although it has the potential to be realized, it often leaves problems in terms of reliability such as particle settling and clogging caused by dry film formation, and replaces all water-soluble dye type recording agents. Has not reached.

[0014]

SUMMARY OF THE INVENTION In view of the above situation, the inventors of the present invention have conducted intensive research and, as a result, arrived at the next invention. That is, the present invention provides (a) 1 to 40 wt% of fine particles containing a polyester resin colored with a dye and / or a pigment as a main component, and (b) non-spherical particles having an average particle diameter in terms of weight of 0.05 to 2.0 μm. Is a colored fine particle water dispersion containing as essential components, wherein the non-spherical particles have a sphericity of 1.2 or more, and the non-spherical resin fine particles are lower alcohols. And / or alkylene glycol and / or alkanolamines are non-swelling at room temperature, which is a colored fine particle water dispersion, wherein the non-spherical resin fine particles are formed from an ethylene / (meth) acrylic acid copolymer. Is an aqueous dispersion of colored fine particles, wherein the non-spherical resin fine particles contain a polyester resin as a main component. A colored particle aqueous dispersion, characterized in that it.

Further, the colored fine particle water dispersion is characterized in that the coloring of the polyester resin is carried out by a hydrophobic dye which is insoluble or hardly soluble in water and soluble in an organic solvent. An aqueous dispersion of colored fine particles, wherein the ionic group contained in the resin is an organic amine salt of a carboxylic acid group. First, (a) the fine particles containing a polyester resin colored with a dye and / or a pigment as a main component will be described. The polyester resin in the present invention is obtained by condensation of polyvalent carboxylic acids and polyvalent alcohols. Examples of the polycarboxylic acid used in the polyester resin include dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid,
Aromatic dicarboxylic acids such as 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and diphenic acid,
Aromatic oxycarboxylic acids such as p-oxybenzoic acid, p- (hydroxyethoxy) benzoic acid, hexahydrophthalic acid and tetrahydrophthalic acid, aromatic unsaturated polycarboxylic acids such as phenylenediacrylic acid, succinic acid and adipine Acids, azelaic acid, sebacic acid, dodecanedicarboxylic acid and other aliphatic dicarboxylic acids, fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid and other unsaturated polycarboxylic acids, and cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid Examples of the alicyclic dicarboxylic acid and the like, and examples of the polyvalent carboxylic acid include trivalent or higher polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid.

Examples of the polyvalent alcohols used in the polyester resin include aliphatic polyvalent alcohols, alicyclic polyvalent alcohols, aromatic polyvalent alcohols and the like.
Examples of the aliphatic polyhydric alcohols include ethylene glycol
, Propylene glycol, 1,3-propanedioe
2,3-butanediol, 1,4-butanediol
1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, dimethylol heptane, diethylene glycol, dipropylene glycol,
2,2,4-trimethyl-1,3-pentanediol,
Polyethylene glycol, polypropylene glycol,
Aliphatic diols such as polytetramethylene glycol,
Examples thereof include trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, and other triols and tetraols. As the alicyclic polyvalent alcohols, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A and ethylene oxide of hydrogenated bisphenol A Adducts and propylene oxide adducts,
Examples thereof include tricyclodecanediol and tricyclodecane dimethanol.

As the aromatic polyhydric alcohols, paraxylene glycol, metaxylene glycol, orthoxylene glycol, 1,4-phenylene glycol, 1,
Examples thereof include ethylene oxide adduct of 4-phenylene glycol, bisphenol A, ethylene oxide adduct of bisphenol A, and propylene oxide adduct. Further, as polyester polyol, ε
Examples thereof include lactone-based polyester polyols obtained by ring-opening polymerization of lactones such as caprolactone. In addition to these, a monofunctional monomer may be introduced into the polyester for the purpose of blocking a part of the polar group at the terminal of the polyester polymer. Examples of monofunctional monomers include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid. Acid, tert-butylbenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, phenylacetic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, octanecarboxylic acid, lauric acid, stearyl acid And monocarboxylic acids such as lower alkyl esters thereof, or monoalcohols such as aliphatic alcohols, aromatic alcohols and alicyclic alcohols.

The polyester resin preferably used in the present invention is an aromatic dicarboxylic acid and / or alicyclic dicarboxylic acid as a polyvalent carboxylic acid component, and an aliphatic diol and / or alicyclic as a polyvalent alcohol component. It uses diol. In the present invention, it is preferable to use a polyester resin obtained from an aromatic dicarboxylic acid and an aliphatic diol, or a polyester resin obtained from an alicyclic dicarboxylic acid, an aliphatic diol and an alicyclic diol. The polyester resin can be obtained by a conventional method such as a vacuum polymerization method or a reduced pressure polymerization method. The former is a method used for polymerizing polyethylene terephthalate or the like, which is used for fibers, films, plastic bottles and the like, and a polyester having a relatively high molecular weight can be obtained. The latter is a method used when polymerizing an unsaturated polyester resin such as an alkyd resin, and a polyester having a relatively low molecular weight is obtained. In addition to these conventional methods, the polyester resin can be obtained by an acid chloride method or the like.

The number average molecular weight of the polyester resin in the present invention is preferably 1,000 to 20,000,
It is more preferably 1500 to 10,000 and still more preferably 2000 to 5000. If the molecular weight is low, the resulting coating film may have insufficient physical properties. If the molecular weight is too high, dry film formation may be hindered. The glass transition temperature of the polyester resin in the present invention is 20
The temperature is preferably not lower than 40 ° C, more preferably not lower than 40 ° C, still more preferably not lower than 50 ° C, and further preferably in the range of 60 to 80 ° C. If the glass transition temperature is too low, the dried coating film becomes tacky, which may be inconvenient for some applications. If the glass transition temperature is too high, dry film formation may be hindered.

The polyester resin preferably contains an ionic group in the range of 20 to 2000 eq./ton. Examples of the ionic group that may be introduced into the polyester include alkali metal sulfonates or ammonium sulfonates, alkali metal carboxylates or ammonium carboxylates, sulfuric acid groups, phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, or Anionic groups such as ammonium salts and alkali metal salts thereof, or first
A cationic group such as a primary to tertiary amine group can be used. The ionic group can be introduced by using an ionic group-containing monomer. In order to introduce a cationic group, 2-aminopropane 1,3 diol, nitrile monoalkanol, nitrile dialkanol and nitrile trialkanol can be preferably used. In order to introduce a sulfonic acid alkali metal base or ammonium sulfonate base into polyester, sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7 dicarboxylic acid, 5
[4-Sulfophenoxy] isophthalic acid, metasulfobenzoic acid, etc. may be copolymerized with the polyester such as an alkali metal salt or ammonium salt of a mono- or polyvalent carboxylic acid having a sulfonic acid group.

Alkali metal ions such as Li, Na and K, alkaline earth metal ions, ammonium ions, 1
Examples thereof include salts with primary to quaternary alkylammonium ions and alkanolamines. The content of these ionic groups is 20 to 2000 m with respect to the polyester resin.
Equivalent / 1000 g is required, preferably 20-10
00 m equivalent / 1000 g, more preferably 50 to 500
m equivalent / 1000 g, still more preferably 50-20
It is 0 meq / 1000 g. The ionic group has a function of imparting dispersion stability to the polyester resin fine particles, and when the content of the ionic group is less than the predetermined amount, sufficient water dispersibility may not be obtained, and the ionic group may be ionic. If the content of the group is too large, the polyester resin may become water-soluble and the desired water dispersion may not be obtained.

The ionic group contained in the polyester resin used in the present invention is particularly preferably an organic amine salt of a carboxylic acid group. Such an ionic group can be obtained by introducing a carboxyl group into the polyester resin and then neutralizing it with a base. As the base, alkali metals, ammonia, and other organic amines can be used, and in the present invention, it is particularly preferable to use organic amines. As a method of introducing a carboxyl group into the polyester resin, in the vacuum polymerization method, a method of introducing a polyvalent carboxylic acid anhydride such as trimellitic anhydride, phthalic anhydride, pyromellitic anhydride into the system at the final stage of polymerization of the polyester Can be illustrated. Further, in the vacuum polymerization method, the carboxyl group remaining at the end of the polyester can be used as it is. Alkyl amine as the organic amine,
Alkanolamines, alkylalkanolamines, aromatic amines, cyclic amines, alkylenediamines and the like can be used, and alkanolamines are particularly preferable. Examples of the alkanolamine include monoalkanolamine, dialkylmonoalkanolamine, dialkanolamine, monoalkyldialkanolamine, trialkanolamine, preferably trialkanolamine, and more preferably 2,2 ′. , 2 ″ -nitrile triethanol, tripropanolamine, tributanolamine and trihexanolamine can be used.

The average particle diameter of the polyester resin fine particles in the present invention is preferably in the range of 0.01 to 0.2 μm, more preferably 0.03 to 0.2 μm, and 0.05 to 0.16. Is more preferably 0.0
The range of 5 to 0.1 μm is even more preferable. The method for producing the polyester resin fine particles in the present invention is not particularly limited, and it can be obtained by using a known mechanical or surface chemical dispersion method. That is, a method of mechanically emulsifying a solution of a polyester resin with a high-speed stirrer such as a homogenizer in the presence of an emulsification aid such as a surfactant and removing the solvent can be used. Alternatively, a method of directly pulverizing and finely dispersing the resin by using a jet mill, a freezer mill, a ball mill, an attritor, a sand mill or the like can be used. In the present invention, when the polyester resin is an ionic group-containing polyester resin, the polyester resin has a self-emulsifying property, so that the fine particles can be produced by the phase inversion self-emulsification method. The fine particle dispersion of the polyester resin is prepared by mixing the ionic group-containing polyester resin and the water-soluble organic compound in advance and then adding water, or the ionic group-containing polyester resin, the water-soluble organic compound and water are mixed and heated all at once. It can be obtained by a method or the like.

At that time, a surfactant or the like may be used together. As the water-soluble organic compound, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, tertiary butyl cellosolve,
Acetone, methyl ethyl ketone, tetrahydrofuran,
Dioxane or the like can be used. The water-soluble organic compound is preferably one that can be removed by azeotropic distillation after the ionic group-containing polyester resin is dispersed in water. As a preferred method for obtaining an aqueous dispersion of a preferred colored polyester resin in the present invention, a polyester resin having a predetermined amount of a carboxyl group is first polymerized, and the polyester resin, dye, water-soluble organic compound, and base are sufficiently mixed and dissolved, Then, water can be added to disperse the water, and the water-soluble organic compound can be removed by azeotropic distillation or the like as required. Further, a colored aqueous dispersion can be obtained in the same manner by adding a dye into the system and treating at a high temperature after obtaining an aqueous dispersion of a polyester resin. The water dispersion means a state generally called an emulsion or colloidal dispersion. The ionic group dissociates in the aqueous medium and forms an electric double layer at the interface between the polyester resin and water. When the polyester resin is present as fine microparticles in the aqueous system, an electrostatic repulsive force is generated between the microparticles due to the action of the electric double layer, and the microparticles are stably dispersed in the aqueous medium.

The particle size of the polyester resin fine particles can be controlled by the ionic group content, the ratio of the polyester resin and the water-soluble organic compound at the time of emulsification, the external rotation speed, the temperature and other emulsification conditions. The zeta potential of the colored polyester fine particles of the present invention is not particularly limited, but is in the range of 20 to 70 mV, preferably 30 to 60 mV. Further, in the present invention, an unsaturated monomer is introduced into polyester, and styrene, divinylbenzene,
It is also possible to swell the dispersed fine particles with acrylic acid or methacrylic acid, or an ester thereof, and post-crosslink. In the present invention, the polyester resin fine particles need to be colored with a dye. As the coloring matter, either a pigment or a dye may be used.

More specifically, as a pigment, C.I. I. Pigment Yellow 3, 13, 1
4, 15, 16, 17, 185, C.I. I. Pigment Red 47, 48, 58,
81, 95, 122, 184, 185 C.I. I. Pigment Violet 23 C.I. I. Pigment Blue 15, 16 carbon blacks and the like can be preferably used. Further, the dye is not particularly limited as long as it can dye the crosslinked polyester resin firmly. When the polyester resin contains an anionic group, it is dyed with a cationic dye such as a basic dye, and when it contains a cationic group, it is dyed with an anionic dye such as an acid dye, a direct dye or a reactive dye. can do. Further, disperse dyes, oil dyes, some vat dyes, reactive disperse dyes and the like used for dyeing polyester fibers can be used.

Examples of the acid dye in the present invention include C.I. I. Known acid dyes classified as Acid Color can be used. In addition, some C.I. I. A dye classified as Direct Color can also be used as an acid dye. These are azo, anthraquinone, quinophthalone, triallylmethane, xanthene, phthalocyanine, and other dye skeletons to which about 1 to 4 anionic groups (mostly sodium sulfonate groups) are introduced. For process color use, C.I. I. Acid Yell
Of ow, Hue is Green Yellow,
Alternatively, a dye classified as Bright Greenish Yellow may be C.I. as magenta. I. Acid
Of Red, Hue is Bluish Red or B
dyes classified as light Blue Red,
And / or C.I. I. H in Acid Violet
ue is Reddish Violet, or Brig
A dye classified as ht Reddish Violet is C.I. I. H in Acid Blue
ue is Greenish Blue, or Bright
t Greenish Blue, and / or C.I.
I. Hue is Bluish in Acid Green
Green or Bright Bluish G
Dyes classified as reen are preferably used alone or appropriately mixed.

The basic dyes in the present invention include acridine type, methine type, polymethine type, azo type, azomethine type, xanthene type, thioxanthene type, oxazine type,
Known basic dyes such as thioxazine type, triallylmethane type, cyanine type, anthraquinone type and phthalocyanine type can be used. Especially for the three primary colors of process color, C.I. I. Basic Yel
low 11, 12, 13, 21, 23, 24, 33,
40, 51, 54, 63, 71 and 87 are C.I. I. Basic Red 13, 14, 45, 1
9, 26, 27, 34, 35, 36, 38, 39, 4
2, 43, 45, 46, 50, 51, 52, 53, 5
6, 59, 63, 65, 66, 71, C.I. I. Basi
c Violet 7, 11, 14, 15, 16, 1
8, 19, 20, 28, 29, 30, 33, 34, 3
5, 36, 38, 39, 41, 44 are C.I. I. Basic Blue 3, 22, 33, 4
1, 45, 54, 63, 65, 66, 67, 75, 7
7,85,87,88,109,116 are preferably used. Such an ionic dye can be used in the range of 1 to 98 mol%, preferably 20 to 90 mol% based on the ionic group equivalent contained in the polyester resin.

In the present invention, it is preferably colored with "a dye which is insoluble or sparingly soluble in water and soluble in an organic solvent". The "dye that is insoluble in water or sparingly soluble in water and soluble in an organic solvent" in the present invention is an oil-soluble dye,
Disperse dyes and some bath dyes can be exemplified. These are "Solve" in the color index.
nt Dye "," Disperse Dye "," V
at Dye ”. Chemically, anthraquinone dye, azo dye, disazo dye, triazo dye, phthalocyanine dye, indigo dye, methine dye, nitro dye, quinophthalone dye, quinoline dye, cyanomethine dye, A triphenylmethane dye, a xanthene dye, etc. can be used. These are excellent in fastness to light, fastness to sublimation, hue, and saturation, and are preferable as three primary colors for process color. In addition, known dyes and pigments may be used in combination for fine adjustment of hue. Such a dye is blended in the range of 0.2 to 30% by weight, more preferably 2 to 25% by weight, still more preferably 5% by weight, based on the polyester resin.
-20% by weight, and even more preferably 10-20% by weight. If the blending amount is too small, a sufficient coloring density cannot be obtained. On the contrary, if the blending amount is too large, the stability of the water dispersion is impaired.

Next, (b) the weight-converted average particle diameter is 0.05.
The non-spherical particles in the range of up to 2.0 μm will be described. The average asphericity of the non-spherical shape is preferably 1.2 or more, more preferably 1.5 or more, still more preferably 2.0 or more, and further preferably 2.5 or more. Here, the asphericity is (1) the ratio of the perimeter of the projected figure to the circumference of the area-converted circle in the projected figure where the particles are projected onto the plane (2) the ratio of the major axis to the minor axis of the projected figure (3) It is defined by the ratio of the measured specific surface area to the specific surface area calculated from the volume-converted particle diameter, and preferably the smallest value among the numerical values calculated by these methods is taken as the non-sphericity. The asphericity is preferably measured using an image processing device or the like. Since it is expected that a measurement error will occur considerably in actual measurement, it is necessary to calibrate in advance using particles having a high sphericity, for example, latex particles for microscope calibration, and then perform the measurement.

The particle size in terms of weight is synonymous with the particle size in terms of volume, and indicates the particle size of a solid sphere having the same weight or volume as the non-spherical particles. The particle size in terms of weight can be preferably determined by the Coulter counter method. Accurate measurement is difficult in a centrifugal sedimentation type particle size distribution analyzer because the particle shape affects the sedimentation velocity.
Also in a light scattering type particle size distribution meter, the particle shape influences the scattered light intensity distribution, making accurate evaluation difficult. In addition, a sphere-converted diameter obtained by using an image processing apparatus can be used as an alternative means. The weight-converted particle diameter in the present invention is indispensably in the range of 0.05 to 2.0 μm,
The range of 0.05 to 1.0 μm is more preferable, and 0.08
Is more preferably in the range of 0.1 to 0.3 μm.
Is still more preferable. The specific gravity of the resin constituting the non-spherical particles of the present invention is not particularly limited, but preferably 0.
9 to 1.3, more preferably 0.95 to 1.10.
Is more preferable, the range is 0.93 to 1.00, and the range is 0.94 to 0.98. In the present invention, the lower limit of the particle size distribution is not limited as long as problems such as increase in ink viscosity do not occur, and a range up to about 0.01 μm is allowed. However, the upper limit of the particle size distribution is about 2.0 μm, preferably 1.5 μm.
m, more preferably 1.2 μm or less.

That is, the preferred particle size distribution in the present invention is not necessarily a normal distribution, but a shape with a small tail on the side of the small diameter particles is preferred. Particles with high monodispersity are not always preferred. Such non-spherical resin fine particles are preferably non-swelling with respect to the water-soluble organic compound lower alcohol and / or alkylene glycol and / or alkanolamine which is an ink additive. Here, the non-swelling property means that the resin does not dissolve in the organic compound as a physical property as a bulk,
It means a resin that does not absorb 10 wt% or more, preferably 5 wt% or more of the organic compound, and from another viewpoint, 10 ° C. or more in an aqueous dispersion of such resin particles,
It preferably means that the film formation temperature does not decrease by 5 ° C. or more. From another point of view, the softening temperature of the resin, or in the region of the glass transition temperature or less,
It is meant that the presence of such a water-soluble organic compound does not cause an effective change in particle shape.
When swelling to these water-soluble organic compounds that are supplementarily added to the ink, dry film formation of resin particles occurs at the nozzle tip, which causes nozzle clogging, as well as an essential requirement of the present invention. That is, the shape of the non-spherical particles cannot be maintained, and the effect of the present invention disappears.

The spherical particles used in the present invention are used as an aqueous fine dispersion, and the minimum film forming temperature in such an aqueous dispersion is preferably 40 ° C. or higher, and 60 ° C.
The above is more preferable, and even more preferably 70 to
It is preferably in the range of 100 ° C, and more preferably in the range of 80 to 100 ° C. In order to achieve such a minimum film forming temperature, ASTM D1525-
The Vicat softening point defined by 70 is preferably 40 to 100, more preferably 45 to 80 ° C, and further preferably 50 to 70 ° C. Further, the glass transition temperature is 40 ° C or higher, further 55 ° C.
It is preferable that it is above.

Generally, as methods for obtaining fine particles of resin, (1) suspension polymerization method (2) emulsion polymerization method (3) phase inversion (self) emulsion method and the like are known. The microparticles obtained by the method are all substantially spherical. In the prior art, since the resin fine particles, emulsion, latex, etc., which have been blended in recording materials such as writing instruments and ink jet recording inks, use spherical fine particles obtained by these methods, a sufficient recording quality improving effect is obtained. I couldn't get it. The non-spherical particles used in the present invention are preferably (1) mechanical pulverizing means (2) dispersion polymerization method (3) emulsion polymerization method, phase inversion (self) emulsification method It can be obtained by subsequent aggregation. The material of the non-spherical particles preferably used in the present invention is mainly composed of ethylene / (meth) acrylic acid copolymer, and is partially ionically cross-linked with an alkali metal ion, an alkaline earth metal ion, an ammonium ion or the like. It is a so-called ionomer resin.

Such an aqueous dispersion of non-spherical particles of an ionomer resin is subjected to forced mechanical emulsification in which heating and mechanical stirring are used in combination,
It can be obtained by a method other than emulsion polymerization, and is available under the trade names of Chemipearl S-100, S-200 and S-30.
0, SA-100 type [manufactured by Mitsui Petrochemical Co., Ltd.] and the like. The material for the non-spherical particles preferably used in the present invention is a polyester resin. The polyester resin is obtained by polycondensation of mono-polyhydric carboxylic acids containing dicarboxylic acid as a main component and mono-polyhydric alcohols containing diols as a main component, and the same products as the colored particles of the present invention are used. be able to. The non-spherical particles of the present invention can be obtained by, for example, secondary aggregating the thermoplastic spherical particles thus obtained in a temperature range slightly above the softening temperature and partially fusing them. it can. The secondary aggregation is preferably performed in the slow aggregation region. Specifically, secondary aggregation can be caused by adding an electrolyte to an aqueous dispersion of fine resin particles and raising the temperature of the aqueous dispersion to a temperature near or slightly higher than the glass transition temperature or softening temperature of the resin. The amount of electrolyte added is preferably in a range not exceeding the critical aggregation concentration in the addition temperature range.

The secondary aggregation method can be applied to resins other than the aqueous dispersion of polyester resin. The shape of the particles obtained by the secondary aggregation can be controlled by the treatment time, temperature, the amount of electrolyte added, and the like. In the present invention, both the colored polyester fine particles and the non-spherical particles are essential components, and the content thereof is 1 to 40 wt.
% Is essential, and 1-40 wt% of colored polyester fine particles
On the other hand, 1 to 30% by weight of non-spherical fine particles are preferable, 10 to 40% by weight of colored polyester fine particles, and 2 to non-spherical fine particles.
20% by weight is more preferable, and colored polyester fine particles 1
0 to 40 wt% and 5 to 20 wt% of non-spherical fine particles are more preferable, and 10 to 30 wt% of colored polyester fine particles and 5 to 10 wt% of non-spherical fine particles are still more preferable. The balance is an aqueous medium. In the present invention, the total amount of the colored polyester resin fine particles and the non-spherical fine particles is preferably 50% by weight or less, more preferably 10 to 40% by weight, still more preferably 15 to 30% by weight. . In the present invention, it is preferable that the relationship of the particle diameter of the colored polyester resin particles ≦ the particle diameter of the non-spherical particles is satisfied. Here, the particle size is the average particle size or the maximum particle size.

Fluorine-based or silicone-based antifoaming agents can be added to the colored water dispersion of the present invention. Furthermore, various fungicides and fungicides, and if necessary,
Inorganic and organic pigments may be added to the extent that transparency is not impaired. Further, addition of a trace amount of alkali metal ions or alkaline earth metal ions of about 5 to 50 ppm may be preferable in order to reduce the viscosity of the aqueous dispersion. The pH of the colored aqueous dispersion of the present invention is preferably 4 or higher, more preferably 6 or higher, even more preferably 7.5 or higher,
The range from 7.5 to 9.5 is even more preferred. The viscosity of the colored aqueous dispersion of the present invention is preferably in the range of 1.5 to 30 centipoise, more preferably 1.8 to 15 centipoise, still more preferably 2.0 to 10 centipoise, and 3.0 to 6. A range of 0 centipoise is even more preferred. The surface tension of the colored water dispersion of the present invention is not particularly limited, but at 25 ° C., preferably 1
It is 0 to 72, more preferably 20 to 70, and further preferably 30 to 60 dyn / cm. Although the viscosity of the colored aqueous dispersion of the present invention is not particularly limited,
0.9 to 100 at 25 ° C., preferably 1.0 to 2
0 is more preferably 1.2 to 5.0, still more preferably 1.3 to 2.8 centipoise.

The aqueous medium may contain various water-soluble additives. As the additive, a water-soluble organic compound can be exemplified. Water-soluble organic compounds include methanol, ethyl alcohol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butyl cellosolve, tertiary butyl cellosolve, diethylene glycol. , Triethylene glycol,
Examples thereof include polyethylene glycol, thiodiglycol, glycerin, 2,2 ′, 2 ″ -nitrile triethanol, ethylenediamine and alkylene glycol monoether. Such a water-soluble organic compound can be appropriately added within a range not exceeding 50% of the aqueous medium. A fluorine-based or silicone-based antifoaming agent can be added to the aqueous medium of the present invention. Furthermore, various fungicides and fungicides, and if necessary, inorganic and organic pigments may be added to the extent that transparency is not impaired. Again 5
Addition of a trace amount of about 50 ppm of alkali metal ion or alkaline earth metal ion is preferable for decreasing the viscosity of the aqueous dispersion.

The pH of the aqueous dispersion of the present invention is preferably 4 or higher, more preferably 6 or higher, even more preferably 7.5 or higher, still more preferably 7.5 to 9.5. In the present invention, an ultraviolet absorber, an antioxidant and the like can be added for the purpose of improving light resistance and heat resistance. As the ultraviolet absorber and the light stabilizer, a salicylate compound, a benzophenone compound, a benzotriazole compound, etc. can be used. Examples of the metal deactivator include N-salicyloyl-N'-aldehyde hydrazine, N-salicyloyl-N'-acetylhydrazine, N, N'-diphenyl-oxamide, N, N'-di (2-hydroxyphenyl) oxamide and the like. Can be used. 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, N-phenyl-N'-isopropyl-p as an ozone deterioration inhibitor
-Phenylenediamine and the like can be used. As the radical chain inhibitor (primary antioxidant), a phenol compound, an amine compound, an ascorbic acid compound or the like can be used. Sulfur compounds as peroxide decomposers (secondary antioxidants), citric acid as synergists,
Phosphoric acid or the like can be used.

In the present invention, it is preferable to use at least one ultraviolet absorber selected from the group consisting of benzotriazole type, benzophenone type and benzosalicylate type. The blending amount of these antioxidants is 0.
The amount is 01 to 5.0% by weight, preferably 0.02 to 1.0% by weight, and more preferably 0.05 to 0.5% by weight. The fine particles of the colored polyester resin, which is the first component in the colored water dispersion of the present invention, have a high concentration and high transparency, and have a function relating to good colorability. Such a property is because the polyester resin of the present invention has a very large tolerance to the dissolution of the dye, such as styrene, acrylic,
It cannot be obtained with an aqueous dispersion obtained by vinyl emulsion polymerization such as vinyl chloride. On the other hand, the non-spherical particles, which are the second component in the colored water dispersion of the present invention, have a recording quality, particularly a function of preventing bleeding in a recording medium on which bleeding easily occurs. As described above, it is widely known that the recording quality is improved when resin fine particles are added to the recording agent, and many patent proposals have been made. However, they concern only the recording quality and do not consider the reliability of the ink itself with respect to storage stability. An object of the present invention is to provide an ink that realizes high recording quality while satisfying the reliability of storage stability, and only a specific one of many synthetic resin fine particles satisfies this purpose. It was made as a result of finding out that.

Conventionally, it has been attempted to add resin fine particles to improve the recording quality of an aqueous solution of a water-soluble dye, an ink for a writing instrument containing a pigment, an aqueous microdispersion such as carbon black as a main component, an ink for inkjet recording and the like. Came.
There is no example of the resin particles found in the conventional proposals in which the particle shape is specified. Unless otherwise noted,
The resin particles found in such a proposal are manufactured by a method (emulsion polymerization,
From the viewpoint of suspension polymerization), it can be interpreted as substantially spherical. The attempt to improve the recording quality by adding such resin particles is basically based on the idea of suppressing bleeding by closing the gaps between fibers contained in the recording paper with particles larger than the gaps. . However, the conventionally used substantially spherical particles have a large gap between the particles and cannot completely close the fiber gap of the recording paper, and the effect of preventing ink blurring is insufficient. The non-spherical particles whose shape is regulated by the present invention are packed while being intricately entangled in the fiber gap, so that the particle gap is smaller than when spherical particles having the same particle diameter are used, and the recording quality improving effect is remarkable. . Further, regarding the material of such non-spherical particles, low swelling property is required for the hydrophilic solvent used as an additive for ink. This has the meaning of preventing the resin from becoming spherical due to softening and swelling of the resin.

Further, the non-spherical particles of the present invention have a remarkable effect of improving recording quality even with a smaller weight-converted spherical particle diameter than the substantially spherical particles. It can be interpreted that this is because the resin particles have a non-spherical shape and thus have a small mass and a large viscous resistance. Further, it is noteworthy in the present invention that the recording density is improved by adding such resin fine particles to the ink. This fact means that the recording agent, which permeates and diffuses along with the medium (water) along the fiber of the recording paper, is suppressed by the added resin fine particles to suppress bleeding. It can be understood that it is because a lot remains. This effect is conspicuously observed particularly in the resin fine particles satisfying the limiting conditions of the present invention, so that it is possible to evaluate the high effect of preventing bleeding.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples shown here.

【Example】

[Polymerization of Polyester Resin] In an autoclave equipped with a thermometer and a stirrer, 96 parts by weight of dimethyl terephthalate, 92 parts by weight of dimethyl ester of isophthalic acid, 6 parts by weight of dimethyl ester of sulfoisophthalic acid of 5 sodium, ethylene. 72 parts by weight of glycol, 103 parts by weight of neopentyl glycol and 0.1 part by weight of tetrabutoxytitanate were charged and heated at 150 to 220 ° C. for 180 minutes to carry out a transesterification reaction. Then, after raising the temperature to 240 ° C.,
Gradually reduce the system pressure to 10 mmHg after 30 minutes,
The reaction was continued for 90 minutes. Copolyester resin (A
1) was obtained. The obtained copolyester resin has an average molecular weight of 3100, an acid value of 5 eq./ton and a glass transition temperature of 5.
It was 8 ° C. and had a sodium sulfonate group equivalent of 98 eq.ton.

In an autoclave equipped with a thermometer and a stirrer, 196 parts by weight of cyclohexanedicarboxylic acid dimethyl ester, 102 parts by weight of ethylene glycol, 99 parts by weight of tricyclodecane dimethanol, and tetrabutoxy titanate. 0.1 part by weight was added to the mixture and heated at 150 to 220 ° C. for 180 minutes to carry out a transesterification reaction. Then, after raising the temperature to 240 ° C.,
Gradually reduce the system pressure to 10 mmHg after 30 minutes,
The reaction was continued for 120 minutes. After that, the atmosphere in the autoclave was replaced with nitrogen gas and the pressure was adjusted to atmospheric pressure. The temperature was kept at 200 ° C, 4 parts by weight of trimellitic anhydride was added, and the reaction was carried out for 60 minutes to obtain a copolymer polyester resin (A
2) was obtained. The obtained copolyester resin had an average molecular weight of 3,500, an acid value of 214 eq./ton and a glass transition temperature of 70 ° C.

[Production of Colored Water Dispersion] A four-necked 10 liter separable flask equipped with a thermometer, a condenser and a stirring blade was placed in a polyester resin (A1) at 200 parts by weight.
100 parts by weight of methyl ethyl ketone, 50 parts by weight of tetrahydrofuran, and 20 parts by weight of HM-0301 (oil-based dye cake) [manufactured by Mitsui Toatsu] as a dye were charged and dissolved at 70 ° C. Next, 500 parts by weight of ion-exchanged water at 70 ° C. was added to disperse the water, and the distillation fraction was heated to 1 in a distillation flask.
It distilled until it reached 03 degreeC and it was set as the colored polyester aqueous dispersion (B1). The finely dispersed particles present in the obtained polyester aqueous dispersion had an average particle size of 0.12 μm and a zeta potential of −46 mV. 200 parts by weight of polyester resin (A2), 200 parts by weight of methyl ethyl ketone, 100 parts by weight of tetrahydrofuran and 100 parts by weight of tetrahydrofuran were added to a four-necked 10 liter separable flask equipped with a thermometer, a condenser and a stirring blade. I. Disperse Red60
(AmesNega) [Mitsui Toatsu Dye] Conc Cake 10 parts by weight, Macrolex Yellow 3G [BAYER] 1
0 part by weight was charged and dissolved at 70 ° C.

Next, 6 parts by weight of 2,2 ′, 2 ″ -nitriletriethanol as a base was added, and then 500 parts by weight of ion-exchanged water at 70 ° C. was added to disperse the water, followed by distillation in a distillation flask. It was distilled until the minute temperature reached 103 ° C., and after cooling, water was added to give a colored polyester aqueous dispersion (B2) having a solid content concentration of 25%. The finely dispersed particles present in the obtained polyester aqueous dispersion had an average particle diameter of 0.22 μm and a zeta potential of −55 mV.

[Preparation of Polyester Particles] In an autoclave equipped with a thermometer and a stirrer, 198 parts by weight of cyclohexanedicarboxylic acid dimethyl ester, 165 parts by weight of propylene glycol, and 91 parts by weight of tricyclodecane dimethanol. , And tetrabutoxy titanate (0.1 part by weight) were charged and heated at 150 to 220 ° C. for 180 minutes to carry out the transesterification reaction. Then, after raising the temperature to 240 ° C.,
Gradually reduce the system pressure to 10 mmHg after 30 minutes,
The reaction was continued for 60 minutes. After that, the atmosphere in the autoclave was replaced with nitrogen gas and the pressure was adjusted to atmospheric pressure. Keeping the temperature at 200 ° C., 4 parts by weight of trimellitic anhydride, 20 parts by weight of maleic anhydride were added, and the reaction was carried out for 60 minutes to prepare a copolymerized polyester resin (A
3) was obtained. The obtained copolyester resin had a number average molecular weight of 3100, an acid value of 214 eq./ton and a glass transition temperature of 62 ° C.

A four-necked 10 liter separable flask equipped with a thermometer, a condenser, and a stirring blade was charged with 200 parts by weight of the copolymer polyester resin (A3), 100 parts by weight of methyl ethyl ketone, and 50 parts by weight of tetrahydrofuran, at 70 ° C. It was dissolved in. Then 2,2 'as a base,
After adding 5 parts by weight of 2 ″ -nitrile triethanol, 7
500 parts by weight of 0 ° C. ion-exchanged water was added. In the system, phase inversion self-emulsification occurred and an aqueous dispersion was produced. Further distill in a distillation flask until the distillate temperature reaches 103 ° C,
After cooling, water was added to obtain a polyester aqueous dispersion (B3) having a solid content concentration of 25%. The average particle size of the finely dispersed particles present in the obtained polyester aqueous dispersion was 0.08 μm, the zeta potential was −55 mV, and the particle shape by SEM observation was almost spherical.

900 parts by weight of the obtained water dispersion (B3) was placed in a four-necked 10-liter separable flask equipped with a thermometer, a condenser, and a stirring blade, and 45 parts by weight of styrene in which 2% by weight of azobisbutylnitrile was dissolved. 100 parts by weight of 1N triethanolamine citrate salt (corresponding to the electrolyte) was charged at room temperature, and gently stirred until 95 ° C. up to 0.9 ° C.
The temperature was raised at 2 ° C./minute, the temperature was kept at 95 ° C. for 120 minutes, and then ice was added to quench. The treated aqueous dispersion was dialyzed using an artificial kidney module until the conductivity of the dialysate reached 5 μS / cm or less. The particles present in the obtained aqueous dispersion are S
By EM observation, it was a non-spherical shape in which several to about 10 spherical particles were aggregated and fused in a dendrite form.

The asphericity of the particles obtained by changing the heating rate changed. (C1-C4) Table 1. Polyester fine particles having the particle size and shape shown in Table 1 were obtained.

[Table 1] The asphericity (1) and (2) was obtained by analyzing the SEM photograph of the obtained particles with an image processing device “Image Analyzer V1 (manufactured by Toyobo Co., Ltd.). It was calculated from the specific surface area calculated from the particle size distribution obtained by the counter method and the specific surface area (average value of both companies) obtained by the nitrogen adsorption / desorption method and the mercury injection method. Degree is the asphericity (1) The ratio of the perimeter of the projected figure to the circumference of the area-converted circle in the projected figure in which the particles are projected onto the plane.Asphericity (2) The ratio of the major axis to the minor axis of the projected figure Sphericity (3) This is the ratio of the measured specific surface area to the specific surface area calculated from the volume-converted particle size.

The swelling property of the particles was evaluated by the degree of decrease in the minimum film-forming temperature when 10 wt% of isopropyl alcohol was added to the aqueous dispersion of the resin particles. Decrease in film formation temperature is 5 ℃
When the temperature was within the range, it was evaluated as ◯, when 5 to 10 ° C. was evaluated as Δ, and when it exceeded 10 ° C. Further, non-spherical particles satisfying the requirements of the present invention and spherical particles not satisfying the requirements of the present invention were selected from commercially available resin particles and used in Examples and Comparative Examples. The characteristics of the resin particles used are shown in Table 1. Shown in Here S-100, S
-200, S-300, and SA-100 are ionomer resins containing ethylene-methacrylic acid copolymer (80-90 wt% ethylene, 10-20 wt% methacrylic acid) partially ionically cross-linked by alkali metal ions as a main component. Is a water dispersion obtained by the soap-free emulsification method, which is marketed by Mitsui Petrochemical Co., Ltd. as Chemipearl, and its shape is non-spherical / amorphous. Two
40-V is a flat-shaped fine particle made of polystyrene resin, which is commercially available as Glossdale from Mitsui Toatsu Chemicals, Inc. A W-500 polyolefin wax emulsion, which is an aqueous dispersion of spherical particles marketed by Mitsui Petrochemical Co., Ltd. as Chemipearl.
E-3101 and E-5101 are spherical resin fine particles of styrene or acrylic and are commercially available from Nippon Paint Co., Ltd. under the trade name of Microgel.

Example 1 A recording material was obtained by mixing and preparing samples so as to have the following constitution. Colored polyester fine particles (B1) (non-volatile content) 15.0 wt% Ethylene glycol 4.0 wt% Ethyl alcohol 1.0 wt% Non-spherical particles C1 (non-volatile content) 5.0 wt% Water residual viscosity of the recording agent is 3.2. Centipoise, surface tension is 52d
It was adjusted to yn / cm. Also in the following Examples and Comparative Examples, from the viewpoint of comparison under certain conditions, the recording agent viscosity is within the range of 2.5 to 4.0 centipoise and the surface tension is within the range of 48 to 54 dyn / cm. Was adjusted to. The average particle size is a light scattering type particle size distribution meter, the resin specific gravity is the float-sink method, the minimum film-forming temperature is the usual method, and the Vicat softening point is A.
It measured by the method based on STMD1525-70. Using the obtained trial recording material (1), a width of 0.
A line of 3 mm was marked and the recording quality was visually evaluated. Similarly, a line of 0.3 mm was also drawn on the calligraphy paper, and the thickness of the line was determined from the original line width and the line width actually set to obtain the blur width.

The lined paper was dipped in ion-exchanged water for 5 minutes, and the water resistance was evaluated by the presence or absence of bleeding of the coloring material. Dry average film thickness (weight conversion) 1.0 μm on PPC paper
A solid image was formed so that the recording density was measured by a Macbeth optical densitometer. The results are shown in Table 2. Shown in

[Table 2] Table 2. Medium, recording quality (visual observation): Whisker-like noise per line length of 1 cm (feathering) Less than 1 ◎ 1 to 2 ○ 2 to 4 △ 4 or more ×.

[Examples 2 to 9] [Comparative Examples 1 to 4] In the same manner as in Example 1, colored polyester fine particles (B1) (non-volatile content) 15.0 wt% ethylene glycol 4.0 wt% ethyl alcohol 1.0 wt% Additive particles (non-volatile content) 5.0 wt% A similar recording agent was prepared by replacing only the additive particles with the composition ratio of residual water, and evaluated in the same manner. The results are shown in Table 2. Shown in

Comparative Example 5 A recording material having the following composition was prepared,
The same evaluation was performed. The results are shown in Table 2. Shown in Water-soluble dye C.I. I. Direct Blue 86 Purified product 1.5 wt% Ethylene glycol 4.0 wt% Ethyl alcohol 1.0 wt% Water residual The purification operation of the dye mainly means removal of sodium sulfate which is an inorganic impurity. This trial ink is a so-called typical water-soluble dye type ink that does not contain resin particles.

Comparative Example 6 A recording agent (15) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. Colored polyester fine particles (B1) (non-volatile content) 15.0 wt% Ethylene glycol 5.0 wt% Water residue

Comparative Example 7 A recording material having the following composition was prepared,
The same evaluation was performed. The results are shown in Table 2. Shown in Water-soluble dye C.I. I. Direct Blue 86 Purified product 1.5 wt% Ethylene glycol 4.0 wt% Ethyl alcohol 1.0 wt% Non-spherical particles C1 5.0 wt% Water residue

[Examples 10 to 15] Samples were mixed and prepared so as to have the following constitution to obtain recording agents. Colored polyester fine particles (B2) (non-volatile content) 15.0 wt% Ethylene glycol 4.0 wt% Ethyl alcohol 1.0 wt% Non-spherical particles C4 (non-volatile content) 5.0 wt% Water residue Substituting non-spherical particles to be added below , And similarly evaluated. The results are shown in Table 2. Shown in

[0059]

As described above, the colored water dispersion of the present invention has excellent characteristics as a recording agent having a high recording quality, and can be widely used in writing instruments, various printers, printing machines and the like. It is possible.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C09D 167/02 PKV C09D 167/02 PKV (72) Inventor Yozo Yamada 2 Katata, Otsu, Shiga Prefecture No. 1 Toyobo Co., Ltd. Research Institute

Claims (7)

[Claims] 1. Fine particles 1 to 40 containing (a) a polyester resin colored with a dye and / or a pigment as a main component.
wt% (b) Weight-converted average particle diameter is 0.05 to 2.0 μm
A non-spherical particle in the range of 1. 2. The colored fine particle water dispersion according to claim 1, wherein the sphericity of the non-spherical particles is 1.2 or more. 3. The aqueous dispersion of colored fine particles according to claim 1, wherein the non-spherical resin fine particles are non-swellable with lower alcohol and / or alkylene glycol and / or alkanolamine at room temperature. 4. The non-spherical resin fine particles are ethylene /
The colored fine particle water dispersion according to claim 1, which comprises an ionomer resin comprising a (meth) acrylic acid copolymer. 5. The aqueous dispersion of colored fine particles according to claim 1, wherein the non-spherical resin fine particles contain a polyester resin as a main component. 6. The colored fine particle water dispersion according to claim 1, wherein the polyester resin is colored with a hydrophobic dye which is insoluble or hardly soluble in water and soluble in an organic solvent. 7. The colored fine particle water dispersion according to claim 1, wherein the colored polyester resin contains an ionic group and the contained ionic group is an organic amine salt of a carboxylic acid group.