JPH08253728A - Colored water-base dispersion - Google Patents

Abstract

PURPOSE: To obtain a colored water-base dispersion which does not cause the settling of particles nor the clogging due to film formation by drying and enables a high-quality recording by incorporating fine particles formed mainly from a polyester resin colored with a dye and fine synthetic resin particles into the dispersion. CONSTITUTION: This water-base dispersion has a viscosity of 1.5-30cP, contains as the essential components 0.1-40wt.% fine particles which mainly comprise a polyester resin colored with a dye insol. or hardly sol. in water and sol. in an org. solvent and have an ionic group content of 20-2,000eq/ton and an average particle size of 0.01-0.2μm and 0.5-15wt.% synthetic resin particles which have a specific gravity of 0.9-1.0 and an average particle size of 0.1-3.0μm, are nonswellable by a lower alcohol and/or an alkylene glycol and/or an alkanolamine, and comprise a (co)polymer having 50wt.% or higher ethylene or propylene units, and further contains a water-base medium and other components such as a fluorine- or silicon-based defoaming agent, a fungicide, a bactericide, and a pigment.

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 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.

Japanese Patent Laid-Open Nos. 55-139471 and 3-2
In 50069, an ink using emulsion-polymerized or dispersion-polymerized particles dyed with a dye is proposed. 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 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. 4-18
In 5672, 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 is 0.04 or less, and the sedimentation of the particles is prevented. Is proposed.
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,
Since the stability of the dispersion system is lowered, the colored resin particles are aggregated and the fluid characteristics 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, have arrived at the next invention. That is, the present invention includes: a) 0.1 to 40% by weight of fine particles mainly composed of a polyester resin colored with a dye which is insoluble or sparingly soluble in water and soluble in an organic solvent b) Specific gravity 0.9 to 1 .1, average particle diameter 0.1 to 3.0 μ
m is a colored water dispersion containing 0.5 to 15% by weight of synthetic resin fine particles as an essential component, the specific gravity of the synthetic resin fine particles is in the range of 0.93 to 1.00, and the average particle diameter is 0.3. To 0.8 μm, which is a colored water dispersion, wherein the synthetic resin fine particles are non-swelling to lower alcohol and / or alkylene glycol and / or alkanolamines. An aqueous dispersion, wherein the synthetic resin fine particles are made of a (co) polymer containing 50% by weight or more of ethylene and / or propylene. A colored aqueous dispersion, wherein the synthetic resin fine particles are 50% by weight of methylstyrene. % Or more of a (co) polymer, wherein the synthetic resin fine particles are ethylene /
A colored water dispersion comprising a (meth) acrylic acid copolymer, wherein the synthetic resin fine particles are ethylene /
An emulsification means comprising a colored water dispersion comprising an ionomer resin composed of a (meth) acrylic acid copolymer and having a Vicat softening point in the range of 40 to 100 ° C., wherein the synthetic resin fine particles do not use an emulsifier. And a ionic group of 20 to 2000 eq. / Ton
A colored water dispersion characterized by containing in the range of, wherein the ionic group contained in the polyester resin is a colored water dispersion characterized by being an organic amine salt of a carboxylic acid group, The colored water dispersion is characterized in that the polyester resin fine particles have an average particle size of 0.01 to 0.2 μm.

First, a) the fine particles mainly composed of a polyester resin colored with a dye which is insoluble or sparingly soluble in water and soluble in an organic solvent will be explained. The polyester resin in the present invention is a polyvalent carboxylic acid. Obtained by condensation with polyhydric alcohols. Examples of the polycarboxylic acid used for the polyester resin include dicarboxylic acids such as terephthalic acid, isophthalic acid,
Orthophthalic acid, 1,5-naphthalenedicarboxylic acid,
Aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid and diphenic acid, aromatic oxycarboxylic acids such as p-oxybenzoic acid and p- (hydroxyethoxy) benzoic acid,
Aromatic unsaturated polycarboxylic acids such as phenylenediacrylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid and other aliphatic dicarboxylic acids, fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid Acids, hexahydrophthalic acid, tetrahydrophthalic acid, aliphatic unsaturated polycarboxylic acids, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and other polycarboxylic acids such as trimellitic acid and trimesic acid. Examples thereof include trivalent or higher polycarboxylic acids such as 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, more preferably 1,500 to 10,000, and further preferably 2,000 to 5,000. 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 preferably 20 ° C. or higher, more preferably 40 ° C. or higher, even more preferably 50 ° C. or higher, and further more preferably 60 to.
It is in the range of 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.

Examples of the "dye that is insoluble or sparingly soluble in water and soluble in an organic solvent" in the present invention include oil-soluble dyes, disperse dyes, and some building bath dyes. These are "Sol" in the color index.
"vent Dye", "Disperse Dye",
It is classified as “Vat 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.

More specifically, as an oil-soluble dye, C.I. I. Solvent Yellow 96 C.I. I. Solvent Yellow 162 C.I. I. Solvent Red 49 C.I. I. Solvent Blue 25 C.I. I. Solvent Blue 35 C.I. I. Solvent Blue 38 C.I. I. Solvent Blue 64 C.I. I. Solvent Blue 70 C.I. I. Solvent Black 3 etc. can be illustrated. As a disperse dye, C.I. I. Disperse Yellow 33 C.I. I. Disperse Yellow 42 C.I. I. Disperse Yellow 54 C.I. I. Disperse Yellow 64 C.I. I. Disperse Yellow 198 C.I. I. Disperse Red 60 C.I. I. Disperse Red 92 C.I. I. Disperse Violet 26 C.I. I. Disperse Violet 35 C.I. I. Disperse Violet 38 C.I. I. Disperse Blue 56 C.I. I. Disperse Blue 60 C.I. I. At least one dye selected from Disperse Blue 87 is preferably used. These are particularly excellent in light fastness, sublimation fastness, 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 with respect to the polyester resin,
More preferably 2 to 25% by weight, still more preferably 5 to 20% by weight, still more preferably 10 to 2%.
It is compounded in the range of 0% 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.

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. Examples thereof include salts with alkali metal ions such as Li, Na and K, alkaline earth metal ions, ammonium ions, primary to quaternary alkylammonium ions and alkanolamines.

The content of these ionic groups is required to be 20 to 2000 meq / 1000 g, preferably 20 to 1000 meq / 100 with respect to the polyester resin.
0 g, more preferably 50-500 meq / 1000
g, even more preferably 50-200 meq / 100
0 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 ′. 2,2 ″ -nitrile triethanol, tripropanolamine, tributanolamine, trihexanolamine can be used.

The average particle size 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 transfer self-emulsification method.

The fine particle dispersion of the polyester resin is prepared by previously mixing the ionic group-containing polyester resin and the water-soluble organic compound and then adding water, or the ionic group-containing polyester resin, the water-soluble organic compound and water are collectively treated. It can be obtained by a method of mixing and heating. At that time, a surfactant or the like can be used together. Examples of water-soluble organic compounds include ethanol, isopropanol and butano
, Ethylene glycol, propylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve,
Tertiary butyl cellosolve, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane and 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,
An electric double layer is formed 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 20 to 70 mV, preferably 30 to 60 mV.
It is in the range of mV. In the present invention, it is also possible to introduce an unsaturated monomer into polyester and disperse it in water, and then swell the dispersed fine particles with styrene, divinylbenzene, acrylic acid or methacrylic acid, or an ester thereof, for post-crosslinking.

Next, b) specific gravity of 0.9 to 1.1 and average particle diameter of 0.1 to 3.0 μm.
The synthetic resin fine particles of 0.5 to 15% by weight will be described. It is essential that the synthetic resin fine particles, which are the second essential component in the present invention, have a specific gravity of 0.9 to 1.1 and an average particle diameter of 0.1 to 3.0 μm. The specific gravity of the synthetic resin fine particles is preferably in the range of 0.93 to 1.00, more preferably 0.
It is in the range of 94 to 0.98. The average particle diameter is preferably in the range of 0.1 to 1.0 μm, more preferably 0.2 to 0.8 μm, still more preferably 0.3 to 0.8 μm. If the specific gravity is less than this range, phase separation due to floating of particles may occur when the colored water dispersion is stored for a long period of time. Sedimentation may occur if the specific gravity exceeds this range. On the other hand, if the average particle size is less than this range, the improvement of the recording quality is insufficient, and bleeding is likely to occur especially on a paper of poor quality such as recycled paper.

If the average particle diameter exceeds this range, not only the risk of phase separation due to sedimentation or floating rises, but also the risk of nozzle clogging increases. Even more interestingly, the addition of particles having a particle size exceeding this range gradually reduces the bleeding prevention effect. It is considered that this is because the diameter of the particles is too large and the effect of the particles blocking the fiber gaps of the recording paper is rather reduced. In the present invention, the lower limit of the particle size distribution is not limited as long as there is no problem such as an increase in the viscosity of the colored water dispersion, and is about 0.01 μm
Ranges up to the degree are acceptable. However, the upper limit of the particle size distribution needs to be controlled to about 5.0 μm, preferably 3.0 μm, and more preferably 2.0 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 small diameter particle side is preferred. Particles with high monodispersity are not always preferred.

Further, such synthetic resin fine particles are required to be non-swelling with respect to lower alcohol and / or alkylene glycol and / or alkanolamines which are water-soluble organic compounds which are additives for colored water dispersion. The term "non-swelling" as used herein means that the resin does not dissolve in the organic compound as a physical property as a bulk of the resin and does not absorb the organic compound by 10 wt% or more, preferably 5 wt% or more. From another point of view, it means that a decrease in film forming temperature of 10 ° C. or higher, preferably 5 ° C. or higher does not occur in such an aqueous dispersion of resin particles. When swelling with these water-soluble organic compounds which are supplementarily added to the colored water dispersion, dry film formation of the resin particles occurs at the tip of the nozzle, which causes nozzle clogging.

In the resin fine particles used in the present invention, the minimum film forming temperature is preferably 40 ° C. or higher, and 60
It is more preferable that the temperature is ℃ or higher, and even more
It is preferably in the range of -100 to 100 ° C, and more preferably in the range of 80 to 100 ° C. 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.

The material of the synthetic resin fine particles in the present invention is not particularly limited, and a known vinyl polymer, condensation polymer or the like having the above-mentioned characteristics can be used. The resin fine particles having such properties include (co) polymers containing 50% by weight or more of ethylene and / or propylene, (co) polymers of 50% by weight or more of methylstyrene, and ethylene / (meth) acrylic acid copolymers. The resin fine particles of can be exemplified. As the methylstyrene, any isomer of α, ortho, meta and para positions may be used, but one having a methyl group at the meta position or the para position is particularly preferable. Such resin fine particles can be obtained by any method such as the so-called emulsion polymerization method, but when the resin fine particles obtained by the emulsion polymerization method are particularly used in the present invention, those obtained by a method using no emulsifier such as soap-free emulsion polymerization Is preferably used. This is because emulsifiers and the like often have an unfavorable effect on various properties of the inkjet recording ink.

The resin particles particularly preferably used in the present invention have an ethylene / (meth) acrylic acid copolymer as a main component, and are partially ionically crosslinked by an alkali metal ion, an alkaline earth metal ion, an ammonium ion or the like. It is preferable to use an aqueous dispersion of the so-called ionomer resin. Further, such an ionomer resin preferably has a Vicat softening point in the range of 40 to 100 ° C. An aqueous dispersion of such a resin can be obtained by a method other than emulsion polymerization, such as forced mechanical emulsification in which heating and mechanical stirring are used in combination, and the degree of freedom in the method of obtaining a fine dispersion of resin particles without using an emulsifier. Is high. Examples of water dispersions of such resins include trade names of Chemipearl S-100 and S-
200, S-300, SA-100 type [manufactured by Mitsui Petrochemical Co., Ltd.] and the like.

The synthetic resin fine particles used in the present invention preferably have a non-spherical shape. 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) Ratio of measured specific surface area to specific surface area calculated by volume conversion particle size (4) Defined by the ratio of the diameter of the circumscribed circle to the equivalent circle diameter in a plane projection figure, and preferably calculated by these methods The smallest value among the above values is the asphericity. 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 weight-converted particle diameter is synonymous with the volume-converted particle diameter and indicates the particle diameter 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.

In the present invention, both colored polyester fine particles and synthetic resin fine particles are essential components.
0.1-40 wt% of colored polyester fine particles and 0.5-15 wt% of synthetic resin fine particles are essential,
Colored polyester fine particles 2 to 40 wt%, synthetic resin fine particles synthetic resin fine particles 1 to 10 wt% are preferable, colored polyester fine particles 5 to 40 wt%, synthetic resin fine particles synthetic resin fine particles 2 to 8 wt% are more preferable, and colored polyester fine particles 10 30% by weight and 2 to 8% by weight of synthetic resin particles are more preferable. The balance is preferably an aqueous medium. 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 synthetic resin 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.

The viscosity of the colored aqueous dispersion of the present invention is not particularly limited, but it is 0.9-10 at 25 ° C.
0, preferably 1.0 to 20 and more preferably 1.2 to
5.0, and even more preferably 1.3 to 2.8 centipoise. The water-based 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, polyethylene glycol, thiodiglycol, glycerin, 2,2 ′, 2 ″ -nitrile triethanol, ethylenediamine, alkylene glycol monoether and the like. Such a water-soluble organic compound is used as an aqueous medium.
It can be appropriately added within a range not exceeding 0%. 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.

Further, the addition of a trace amount of alkali metal ions or alkaline earth metal ions of about 5 to 50 ppm is preferable because it lowers 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,
A value of 7.5 or higher is even more preferred, and a range of 7.5 to 9.5 is even more preferred. 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. As the metal deactivator, N-salicyloyl-N'-aldehyde hydrazine, N-salicyloyl-N'-acetylhydrazine,
N, N'-diphenyl-oxamide, N, N'-di (2-hydroxyphenyl) oxamide or the like can be used. As an ozone deterioration inhibitor, 6-ethoxy-2,2,2
4-Trimethyl-1,2-dihydroquinoline, N-phenyl-N'-isopropyl-p-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 can be used as the peroxide decomposer (secondary antioxidant), and citric acid, phosphoric acid, etc. can be used as the synergist. In the present invention, at least one selected from benzotriazole type, benzophenone type, benzosalicylate type
It is preferred to use some types of UV absorbers. The blending amount of these antioxidants is 0.01 to polyester resin.
It is about 5.0% by weight, preferably about 0.02 to 1.0% by weight, and more preferably about 0.05 to 0.5% by weight.

The fine particles of the colored polyester resin, which is the first component in the colored aqueous dispersion of the present invention, have a high concentration and a high transparency and have a function relating to good colorability. Such characteristics are because the polyester resin of the present invention has a very large tolerance for the dissolution of the dye, and cannot be obtained by the aqueous dispersion obtained by vinyl emulsion polymerization of styrene, acryl, vinyl chloride and the like. On the other hand, the synthetic resin fine particles which are the second component in the colored water dispersion of the present invention have a recording quality, especially a function of preventing bleeding in a recording medium in which bleeding easily occurs. As described above, it is widely known that the recording quality is improved when resin particles are added to the recording material, and many patent proposals have been made. However, they are concerned only with the recording quality, and do not give any consideration to the storage stability of the ink itself and the reliability against clogging of inkjet nozzles.
An object of the present invention is to provide an ink that realizes high recording quality while satisfying storage stability and reliability against clogging, and only a specific one of many synthetic resin fine particles has this purpose. It was made as a result of finding that it satisfies. In the present invention, the specific gravity of the resin and the particle size of the dispersed particles are specified at the same time, but the compatibility between the storage stability and the recording quality can be achieved only by satisfying both of them. Further, by satisfying this condition, having a specific softening temperature and realizing a property that the physical properties thereof are not significantly affected by other ink addition components, the reliability against nozzle clogging can be secured.

Further, in the present invention, it is possible to achieve more preferable results by blending the synthetic resin fine particles having such characteristics with the colored polyester fine particles. What is noteworthy is that the recording density is improved in such a configuration.
This fact means that the coloring polyester fine particle component that permeates and diffuses along the fibers of the recording paper together with the medium (water) is stopped by the added synthetic resin fine particles, so that blurring is suppressed and the surface of the recording paper is also suppressed. It can be understood that this is because a relatively large amount remains in the vicinity. This effect is conspicuously observed particularly in the synthetic resin fine particles satisfying the limiting conditions of the present invention, so that it is possible to evaluate the high effect of preventing bleeding. Although the colored polyester resin fine particles themselves have a bleeding preventing function, the present invention provides a higher bleeding preventing function.

The present invention will be described in more detail below with reference to 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 5 sodium sulfoisophthalic acid, 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 dimethyl ester of cyclohexanedicarboxylic acid, 102 parts by weight of ethylene glycol, 99 parts by weight of tricyclodecane dimethanol, 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 copolyester resin (A2). 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) (200 parts by weight).
100 parts by weight of methyl ethyl ketone, 50 parts by weight of tetrahydrofuran, SE as a dye, Thermal Transfer SE
20 parts by weight of 0780 (oil dye cake) [manufactured by BASF] were charged and dissolved at 70 ° C. Then, 500 parts by weight of ion-exchanged water at 70 ° C. was added to disperse the water, and then distilled in a distillation flask until the distillate temperature reached 103 ° C. to obtain a 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. Polyester resin (A2) 2 in a four-necked 10 liter separable flask equipped with a thermometer, condenser and stirring blade.
00 parts by weight, 200 parts by weight of methyl ethyl ketone, 100 parts by weight of tetrahydrofuran, and C.I. I. Di
10 parts by weight of conccake of sperseRed60 (AmesNega) [manufactured by Mitsui Toatsu Dye] and 10 parts by weight of Macrolex Yellow 3G [manufactured by BAYER] were charged and dissolved at 70 ° C.

Next, 6 parts by weight of 2,2 ', 2''-nitrile triethanol as a base was added, and then 500 parts by weight of ion-exchanged water at 70 ° C was added to disperse the water, and then distilled 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.

[0046]

Example 1 A sample was mixed and prepared so as to have the following constitution,
A recording agent (1) was obtained by filtering through a 1.0 μm membrane filter. Colored Polyester Fine Particles (B1) (Nonvolatile Content) 15.0 wt% Ethylene Glycol 4.0 wt% Ethyl Alcohol 1.0 wt% Ethylene-Propylene Copolymer Fine Particles (Nonvolatile Content) 5.0 wt% Water Residue Ethylene-Propylene The copolymer fine particles are an aqueous dispersion of copolymer resin particles obtained by soap-free emulsion polymerization consisting of 90 wt% ethylene and 10 wt% propylene, having an average particle diameter of 0.38 μm, a resin specific gravity of 0.92, and a minimum film forming temperature of 95 ° C. Vicat softening point is 76 ° C.

This resin was not dissolved in methanol, ethanol, isopropyl alcohol, ethylene glycol or nitrile triethanol, and no swelling was observed. Furthermore, 10 wt.% Of isopropyl alcohol was added to 100 wt.% Of the aqueous dispersion prepared to have a nonvolatile concentration of 20 wt.%.
Even when adding 1 part, there is no change in the minimum film formation,
Since there was no change in the particle size, it was judged that the swelling property with a lower alcohol was practically nonexistent. The viscosity of the recording material was adjusted to 3.2 centipoise and the surface tension was adjusted to 52 dyn / 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 /.
It was adjusted to be in the cm range. The average particle diameter was measured by a light-scattering type particle size distribution meter, the resin specific gravity was measured by a float-sink method, the minimum film-forming temperature was measured by a conventional method, and the Vicat softening point was measured by a method according to ASTM D1525-70.

Using the trial recording material (1) thus obtained, a line having a width of 0.3 mm was marked on the recycled paper at the mouth end, 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 water resistance was evaluated by the presence or absence of bleeding of the coloring material. A solid image was formed on the recording paper with a paint brush so that the dry average film thickness (weight conversion) was 1.0 μm, and the recording density was measured with a Macbeth optical densitometer. Fill a test tube with a depth of 10 cm with the trial recording material, and seal it.
Leave for 3 months, and after 3 months, store with the solid content ratio of the presence or absence of precipitates at the bottom of the test tube, the recording agent sampled from 5 mm below the liquid surface, and the recording agent sampled from 1 cm above the bottom. The stability was evaluated. The results are shown in Table 1. Shown in

[0049]

[Table 1] Table 1. Medium MFT: Minimum film forming temperature SP: Vicat softening point Recording quality (visual): Whisker-like noise per line length of 1 cm (feathering) Less than 1 ◎ 1 to 2 ○ 2 to 4 △ 4 or more × is there.

[0050]

Example 2 A recording agent (2) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Colored polyester fine particles (B1) (nonvolatile matter) 15.0 wt% Isopropyl alcohol 0.8 wt% Nitriletriethanol 0.2 wt% Paramethylstyrene-butyl methacrylate copolymer fine particles (nonvolatile matter) 5.0 wt% Water residue Here, the paramethylstyrene-butyl methacrylate copolymer fine particles are an aqueous dispersion of copolymer resin particles obtained by soap-free emulsion polymerization consisting of 75% by weight of paramethylstyrene, 20% by weight of butyl methacrylate and 5% by weight of divinylbenzene. , Average particle diameter 0.45 μm, resin specific gravity 1.02, minimum film forming temperature 102 ° C., Vicat softening point 95 ° C. This resin did not dissolve in methanol, ethanol, isopropanol, ethylene glycol, and nitrile triethanol, but some swelling was observed in methanol. 10 wt% of isopropyl alcohol was added to 100 wt% of the aqueous dispersion prepared to have a nonvolatile concentration of 20 wt%.
Although the minimum film formation decreased by about 4 ° C. when part was added, it was judged that the swelling property with a lower alcohol was low because there was no detectable change in the particle size.

[0051]

Example 3 A recording agent (3) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Colored polyester fine particles (B1) (nonvolatile matter) 15.0 wt% Ethylene glycol 5.0 wt% Isopropyl alcohol 1.0 wt% Ionomer resin fine particles S-200 (nonvolatile matter equivalent) 5.0 wt% Water residue Ethylene-methacrylic acid copolymer partially ionically crosslinked with alkali metal ions (ethylene 80-90 wt%, methacrylic acid 10-
20 wt%) obtained by a soap-free emulsification method and marketed by Mitsui Petrochemical Co., Ltd. as Chemipearl S-200, having an average particle diameter of 0.43 μm and a resin specific gravity of 0.95. The film temperature is 85 ° C and the Vicat softening point is 57 ° C. The resin did not dissolve in methanol, ethanol, isopropyl alcohol, ethylene glycol, and nitrile triethanol, and no swelling was observed. Furthermore, even when 10 wt parts of isopropyl alcohol was added to 100 wt parts of the water dispersion prepared to have a nonvolatile concentration of 20 wt%, the minimum film formation did not change, and the particle size did not change, so the swelling property with lower alcohol is actually It was judged not to rise.

[0052]

Example 4 A recording agent (4) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Colored polyester fine particles (B1) (nonvolatile matter) 15.0 wt% propylene glycol 5.0 wt% butanol 0.8 wt% nitrile triethanol 0.2 wt% citric acid 0.1 wt% ionomer resin fine particles S-300 (nonvolatile matter equivalent) 2.0 wt% water residue Here, the ionomer resin fine particles are ethylene-methacrylic acid copolymer partially ionically crosslinked by alkali metal ions (ethylene 80-90 wt%, methacrylic acid 10-
20 wt%) obtained by a soap-free emulsification method and marketed by Mitsui Petrochemical Co., Ltd. as Chemipearl S-300, having an average particle diameter of 0.53 μm and a resin specific gravity of 0.95. The film temperature is 94 ° C and the Vicat softening point is 67 ° C. It was judged that this resin, like the ionomer resin used in Example 3, has virtually no swelling property with a lower alcohol.

[0053]

Example 5 A recording agent (5) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Colored Polyester Fine Particles (B1) (Nonvolatile Content) 15.0 wt% Ethylene Glycol 5.0 wt% Modified Ionomer Resin Fine Particles SA-100 (Nonvolatile Content) 2.0 wt% Water Residue The modified ionomer resin fine particles are treated with alkali metal ions. Partially ionically cross-linked ethylene-methacrylic acid copolymer (ethylene 80-90 wt%, methacrylic acid 1
It is an aqueous dispersion obtained by a soap-free emulsification method consisting of a graft copolymer obtained by further grafting styrene to 0 to 20 wt%), which is marketed by Mitsui Petrochemical Co., Ltd. as Chemipearl SA-100, and has an average value. Particle diameter 0.75 μm Resin specific gravity 1.00 Minimum film forming temperature 70 ° C. Vicat softening point 55 ° C. This resin did not dissolve in methanol, ethanol, isopropanol, ethylene glycol, and nitrile triethanol, but some swelling was observed in methanol. 10 wt% of isopropyl alcohol was added to 100 wt% of the aqueous dispersion prepared to have a nonvolatile concentration of 20 wt%.
In the case of adding 1 part, the minimum film formation decreased by about 2 ° C., but there was no detectable change in the particle size, so it was judged that the swelling property with a lower alcohol was low.

[0054]

Example 6 A recording agent (6) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Colored Polyester Fine Particles (B1) (Nonvolatile Content) 30.0 wt% Styrene-Butadiene Copolymer Latex (Nonvolatile Content) 2.0 wt% Water Residue The styrene-butadiene copolymer latex contains 25 wt% styrene It is a latex obtained by emulsion polymerization of coalescence. Average particle diameter 0.38 μm Resin specific gravity 0.97 Minimum film forming temperature 24 ° C. Vicat softening point 10 ° C. This resin was dissolved in methanol, ethanol and isopropanol. It did not dissolve in ethylene glycol or nitrile triethanol. When 10 wt parts of isopropyl alcohol was added to 100 wt parts of the water dispersion prepared to have a nonvolatile concentration of 20 wt%, the minimum film formation was lowered by 24 ° C. or more, that is, when the freezing point was not lower than the freezing point, the film was formed by natural drying.

[0055]

Example 7 A recording agent (7) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Colored Polyester Fine Particles (B1) (Nonvolatile Content) 25.0 wt% Ethanol 5.0 wt% Polymethyl Methacrylate Latex (Nonvolatile Content) 1.0 wt% Water Residue Polymethylmethacrylate latex is Microgel P-5002 [Nippon Paint] ] Are commercially available. The average particle diameter is 0.52 μm, the resin specific gravity is 1.19, and the minimum film forming temperature is 120 ° C. and the Vicat softening point is 110 ° C. This resin did not dissolve in methanol, ethanol, isopropanol, ethylene glycol, and nitrile triethanol, but showed slightly softened and swollen surface in methanol and isopropanol. Aqueous dispersion 100 with nonvolatile concentration adjusted to 20 wt%
When 10 wt parts of isopropyl alcohol was added to wt parts, the minimum film formation was lowered by 12 ° C. Although the swelling property was not so high, it was considered to be slightly recognized.

[0056]

Example 8 A recording agent (8) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Colored polyester fine particles (B1) (non-volatile content) 25.0 wt% Diethylene glycol 1.0 wt% Ethylene glycol 3.0 wt% Neopentyl glycol 1.0 wt% Isopropyl alcohol 0.8 wt% Nitrile triethanol 0.2 wt% Acrylic copolymer Combined latex (non-volatile content) 5.0 wt% water residue Acrylic copolymer latex is copolymer latex particles obtained by emulsion polymerization of methyl methacrylate, ethyl methacrylate and butyl methacrylate. Average particle diameter 0.45 μm Resin specific gravity 1.04 Minimum film forming temperature 84 ° C. Vicat softening point 80 ° C. This resin is ethanol, ethylene glycol,
Although it did not dissolve in nitrile triethanol,
Some solubility was observed in methanol and isopropanol. When 10 wt parts of isopropyl alcohol was added to 100 wt parts of the aqueous dispersion prepared to have a nonvolatile concentration of 20 wt%, the minimum film formation was lowered by about 30 ° C.

[0057]

Example 9 A recording agent (9) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. However, 1.
The filtration step with a 0 μm membrane filter was omitted. The results are shown in Table 1. Shown in Colored polyester fine particles (B1) (non-volatile content) 25.0 wt% Diethylene glycol 1.0 wt% Ethylene glycol 3.0 wt% Nitrile triethanol 0.5 wt% Citric acid 0.2 wt% Polyolefin fine particles W-500 (non-volatile content) 5 0.0wt% water residue Polyolefin fine particles are an aqueous dispersion obtained by a soap-free emulsification method consisting of low-molecular weight polyolefin (mainly polyethylene), and marketed by Mitsui Petrochemical Co., Ltd. as Chemipearl W-500. Yes, the average particle diameter is 2.50 μm, the resin specific gravity is 0.92, the minimum film forming temperature is 90 ° C., and the Vicat softening point is 38 ° C. The resin did not dissolve in methanol, ethanol, isopropyl alcohol, ethylene glycol, and nitrile triethanol, and no swelling was observed. Furthermore, even when 10 wt parts of isopropyl alcohol was added to 100 wt parts of the water dispersion prepared to have a nonvolatile concentration of 20 wt%, the minimum film formation did not change, and the particle size did not change, so the swelling property with lower alcohol is actually It was judged not to rise.

[0058]

Example 10 The colored polyester fine particles (B1) in Example 3 were replaced with (B2) to obtain a recording material (10).

[0059]

Example 11 The colored polyester fine particles (B1) in Example 4 were replaced with (B2) to obtain a recording material (11).

[0060]

[Example 12] The colored polyester fine particles (B1) in Example 5 were replaced with (B2) to obtain a recording material (12).
The following evaluation was performed in the same manner. The results are shown in Table 1. Shown in

[0061]

Example 13 In the same manner as in the production of the colored polyester aqueous dispersion (B2), only the dye was used: -Macrolex Yellow 3G [manufactured by BAYER] -Sumikaron Red S-BLF conc cake [manufactured by Sumitomo Chemical Co., Ltd.] -Spiron Blue 2BNH [Hodogaya Chemical] -Oil Black HBB [Orient Chemical] was replaced with yellow water dispersion (Y2), magenta dispersion (M2), cyan dispersion (C2), and black dispersion (K2), respectively. . Using these four colors of colored polyester fine particles, a four-color recording liquid was prepared according to the formulation of Example 3. The obtained recording material was charged into a color printer "Image Jet IO-735X" [manufactured by Sharp Corporation], and image processing software "Photoshop" (manufactured by Adobe)
Was used to print a photo-tone image on a Photo CD on A4 paper for PPC. The resulting image showed good color reproduction. This is because the coating film obtained from such an aqueous dispersion has high color purity and good transparency (intermediate color development by color mixing).
It is shown that it has. Also, when magnified by an optical microscope, each dot was scattered in a spherical shape, and the occurrence of whisker-like noise was hardly seen. Further, the obtained image was immersed in ion-exchanged water for 5 minutes, but especially when the paper was softened, discoloration was not observed and bleeding was not observed.

[0062]

Comparative Example 1 A recording agent (14) having the following composition was prepared in the same procedure as in Example 1 and evaluated in the same manner. The results are shown in Table 1. Shown in Water-soluble dye C.I. I. Direct Blue 86 Purified product 1.0 wt% Ethylene glycol 5.0 wt% Isopropyl alcohol 0.8 wt% Nitrile triethanol 0.2 wt% Water residue The purification operation of the dye mainly means the 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.

[0063]

Comparative Example 2 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

[0064]

Comparative Example 3 Magenta Pigment C.I. I. PigmentRe
25 parts by weight of d122, 5 parts by weight of styrene-maleic acid copolymer partial ester resin (aqueous solution) in nonvolatile content, and 70 parts by weight of water were placed in a ball mill pot, dispersed for 24 hours, filtered through a 1 μm membrane filter, and a recording agent. It was set to 16.

[0065]

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.

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[Procedure amendment]

[Submission date] May 17, 1996

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

The present invention relates to a paint, a water-based paint,
The present invention relates to an aqueous dispersion of a resin which is widely used in paper coating agents, coating materials for films, etc. to recording materials, and particularly to writing instruments, markers, marking pens, etc. The present invention relates to an aqueous dispersion of a colored resin that can be suitably used as an ink recording material used in a dielectric printer or the like.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

When the average particle size exceeds this range, not only the risk of phase separation due to sedimentation or floating rises, but also the risk of clogging of the pen tip increases. Even more interestingly, the addition of particles having a particle size exceeding this range gradually reduces the bleeding prevention effect. It is considered that this is because the diameter of the particles is too large and the effect of the particles blocking the fiber gaps of the recording paper is rather reduced. In the present invention, the lower limit of the particle size distribution is not limited as long as there is no problem such as an increase in the viscosity of the colored water dispersion, and is about 0.01 μm
Ranges up to the degree are acceptable. However, the upper limit of the particle size distribution needs to be controlled to about 5.0 μm, preferably 3.0 μm, and more preferably 2.0 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 small diameter particle side is preferred. Particles with high monodispersity are not always preferred.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

Further, such synthetic resin fine particles are required to be non-swelling with respect to lower alcohol and / or alkylene glycol and / or alkanolamines which are water-soluble organic compounds which are additives for colored water dispersion. The term "non-swelling" as used herein means that the resin does not dissolve in the organic compound as a physical property as a bulk of the resin and does not absorb the organic compound by 10 wt% or more, preferably 5 wt% or more. From another point of view, it means that a decrease in film forming temperature of 10 ° C. or higher, preferably 5 ° C. or higher does not occur in such an aqueous dispersion of resin particles. When swelling in these water-soluble organic compounds that are supplementarily added to the colored water dispersion, dry film formation of resin particles occurs at the tip of the pen, which causes clogging of the pen.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

The material of the synthetic resin fine particles in the present invention is not particularly limited, and a known vinyl polymer, condensation polymer or the like having the above-mentioned characteristics can be used. The resin fine particles having such properties include (co) polymers containing 50% by weight or more of ethylene and / or propylene, (co) polymers of 50% by weight or more of methylstyrene, and ethylene / (meth) acrylic acid copolymers. The resin fine particles of can be exemplified. As the methylstyrene, any isomer of α, ortho, meta and para positions may be used, but one having a methyl group at the meta position or the para position is particularly preferable. Such resin fine particles can be obtained by any method such as the so-called emulsion polymerization method, but when the resin fine particles obtained by the emulsion polymerization method are particularly used in the present invention, those obtained by a method using no emulsifier such as soap-free emulsion polymerization Is preferably used.

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[Correction target item name] 0040

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The fine particles of the colored polyester resin, which is the first component in the colored aqueous dispersion of the present invention, have a high concentration and a high transparency and have a function relating to good colorability. Such characteristics are because the polyester resin of the present invention has a very large tolerance for the dissolution of the dye, and cannot be obtained by the aqueous dispersion obtained by vinyl emulsion polymerization of styrene, acryl, vinyl chloride and the like. On the other hand, the synthetic resin fine particles which are the second component in the colored water dispersion of the present invention have a recording quality, especially a function of preventing bleeding in a recording medium in which bleeding easily occurs. As described above, it is widely known that the recording quality is improved when resin particles are added to the recording material, and many patent proposals have been made. However, they are concerned only with the recording quality, and do not give consideration to the storage stability of the recording agent itself and the reliability against clogging of the pen tip. An object of the present invention is to provide an ink that realizes high recording quality while satisfying storage stability and reliability against clogging, and only a specific one of many synthetic resin fine particles has this purpose. It was made as a result of finding that it satisfies. In the present invention, the specific gravity of the resin and the particle size of the dispersed particles are specified at the same time, but the compatibility between the storage stability and the recording quality can be achieved only by satisfying both of them. Further, by satisfying this condition, having a specific softening temperature and realizing the property that the physical properties thereof are not greatly affected by other additive components, the reliability against clogging of the pen tip is secured.

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[Correction target item name] 0061

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[Correction target item name] 0065

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[0065]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yozo Yamada 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd.

Claims (11)

[Claims] 1. A) 0.1-40 wt% fine particles mainly composed of a polyester resin colored with a dye which is insoluble or slightly soluble in water and soluble in an organic solvent b) Specific gravity 0.9-1 .1, average particle diameter 0.1 to 3.0 μ
A colored water dispersion containing 0.5 to 15% by weight of synthetic resin fine particles of m as an essential component. 2. The specific gravity of the synthetic resin fine particles is 0.93 to
It is in the range of 1.00 and the average particle size is 0.3 to 0.8 μ.
A colored water dispersion characterized in that it is in the range of m. 3. A colored water dispersion, wherein the synthetic resin fine particles are non-swelling with lower alcohols and / or alkylene glycols and / or alkanolamines. 4. A colored water dispersion, wherein the synthetic resin fine particles are composed of a (co) polymer (copolymer or homopolymer) containing 50% by weight or more of ethylene and / or propylene. 5. The synthetic resin fine particles are methylstyrene 5
A colored water dispersion comprising a (co) polymer consisting of 0% by weight or more. 6. A colored water dispersion, wherein the fine particles of synthetic resin are composed of an ethylene / (meth) acrylic acid copolymer. 7. A colored water dispersion, wherein the synthetic resin fine particles are made of an ionomer resin made of an ethylene / (meth) acrylic acid copolymer and have a Vicat softening point in the range of 40 to 100 ° C. 8. A colored water dispersion, wherein the synthetic resin fine particles are obtained by an emulsifying means without using an emulsifier. 9. The polyester resin has an ionic group of 2
0-2000 eq. A colored water dispersion characterized by being contained in a range of / ton. 10. A colored water dispersion, wherein the ionic group contained in the polyester resin is an organic amine salt of a carboxylic acid group. 11. A colored water dispersion, wherein the polyester resin fine particles have an average particle diameter in the range of 0.01 to 0.2 μm.