JPH08253720A - Water-base dispersion of colored fine particle - Google Patents

Abstract

PURPOSE: To obtain a water-base dispersion of colored fine particles which has excellent characteristics as a recording material, giving a high-quality record, by compounding fine particles made mainly from a polyester resin colored by a hydrophobic dye with fine hollow synthetic resin particles. CONSTITUTION: This dispersion contains 0.1-40wt.% fine particles made mainly from a polyester resin colored with a dye insol. or hardly sol. in water and sol. in an org. solvent and 0.5-15wt.% fine hollow synthetic resin particles having an average outer diameter of 0.1-2.0μm and having hollows inside. Pref. the hollows inside the hollow particles are filled with water, more correctly filled with a water-base dispersion medium for an ink jet ink. The hollow particles are pref. nonswellable with a lower alcohol and/or an alkylene glycol and/or an alkanolamine which is a water-sol. org. compd. used as an ink additive.

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 colored resin particles 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. 4-185672 discloses an ink composed of colored resin particles and an aqueous medium, in which a water-soluble compound is dissolved in the aqueous medium so that the difference in specific gravity between the colored resin particles and the aqueous medium is 0.04 or less. It has been proposed to prevent settling of the 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. Japanese Patent Laid-Open No. 4-185673,
In JP-A-4-185674, an effective specific gravity is lowered by swelling colored resin particles with a solvent in an ink composed of colored resin particles and an aqueous medium, and the difference in specific gravity between the colored resin particles and the aqueous medium is set to 0. It is proposed that the value be 04 or less. In such a case, it is difficult to avoid nozzle clogging as described above. Above, we have mainly reviewed recording materials used mainly for ink jet recording, but the sedimentation of particles and the clogging caused by dry film formation are caused by writing tools, markers, marking pens, other types of printers and printing machines. It also occurs when a recording material is used.

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 comprises: 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. 1 to 2.0 μm and 0.5 to 15% by weight of hollow synthetic resin fine particles having cavities inside
Is a colored water dispersion having an essential component, in the resin particles having a cavity inside, a colored water dispersion characterized in that the inside of the cavity is substantially filled with water, the inside A colored water dispersion characterized in that the resin fine particles having voids are non-swelling at room temperature with respect to lower alcohols and / or alkylene glycols and / or alkanolamines, and the resin fine particles having voids inside are a polyester resin. A colored water dispersion characterized in that the main component is a colored water dispersion characterized in that the resin fine particles having the cavities consist of a resin component having a crosslinked structure, wherein the polyester resin Has an ionic group of 20 to 2000 eq. A coloring water dispersion characterized in that the ionic group contained in the polyester resin is an organic amine salt of a carboxylic acid group. And the average particle diameter of the polyester resin fine particles is in the range 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 fastness to light, fastness to sublimation, hue and saturation, and are preferable as the 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 1%.
It is mixed in the range of 0 to 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.

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 an alkali metal sulfonate or ammonium sulfonate into polyester, sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,
7 dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid, metasulfobenzoic acid, etc., such as an alkali metal salt or ammonium salt of a mono- or polyvalent carboxylic acid having a sulfonic acid group, may be copolymerized with the polyester. Li,
Examples thereof include salts with alkali metal ions such as Na and K, alkaline earth metal ions, ammonium ions, primary to quaternary alkylammonium ions, and alkanolamines. The content of the ionic group is required to be 20 to 2000 meq / 1000 g with respect to the polyester resin, preferably 20 to 1000 meq / 1000 g, more preferably 50 to 500 meq / 1000 g, still more preferably 50 to It is 200 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 ′. It is possible to use 2,2 ″ -nitrile triethanol, tripropanolamine, tributanolamine, and trihexanolamine.

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) the hollow synthetic resin fine particles having an average outer particle diameter of 0.1 to 2.0 μm and having voids inside will be described.
The outer diameter of the hollow particles (hollow synthetic resin fine particles) in the present invention must be in the range of 0.1 to 2.0 μm.
The range of 1.0 μm is more preferable, and 0.2 to 0.8 μm
Is more preferable, and the range of 0.3 to 0.6 μm is still more preferable. The hollow rate of the hollow particles used in the present invention is preferably 5 to 95 vol%, more preferably 10 to 90 vol%, still more preferably 20 to 80 vol%, and 30 to
70 vol% is even more preferred.

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 10 μm, preferably 5 μm.
m, more preferably 3 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. The specific gravity of the resin constituting the hollow particles of the present invention is not particularly limited, but preferably in the range of 0.9 to 1.3,
The range is preferably 0.95 to 1.10, more preferably 0.93 to 1.00, and further preferably 0.94 to 0.98. In the present invention, it is preferable that the hollow particles are substantially filled with water. More precisely, it is preferable that the inside of the cavity is filled with an aqueous dispersion medium which is a dispersion medium of the present inkjet ink. Such cavities are substantially filled with air after the ink has been printed on the paper and dried.

The hollow 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. The term "non-swelling" as used herein means a resin that does not dissolve in the organic compound as a physical property as a bulk of the resin, but does not absorb the organic compound in an amount of 20 wt%, preferably 10 wt%, more preferably 5 wt% or more. From another viewpoint, it means that the film-forming temperature does not decrease by 10 ° C. or more, preferably 5 ° C. or more in the aqueous dispersion of the resin particles. From another point of view, it means that the presence of such a water-soluble organic compound does not cause an effective change in the particle shape in the region of the resin softening temperature or below the glass transition temperature. 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. The shape of the hollow particles cannot be maintained, and the effect of the present invention disappears.

The hollow 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, more preferably 60 ° C. or higher, Still further 70-1
It is preferably in the range of 00 ° C, and further 8
It is preferably in the range of 0 to 100 ° C. In order to achieve such a minimum film-forming temperature, the glass transition temperature or softening temperature of the resin is 40 ° C. or higher, preferably 60 ° C. or higher,
More preferably, the temperature is 70 ° C. or higher.

The material of such hollow particles is not particularly limited,
It is used by appropriately selecting from known polymers of vinyl type and condensation type. Examples of such hollow particles include "ROOMPAK OP-84J" and "ROPAK OP OP" manufactured by Rohm and Haas.
-62 "," Low Pake HP-91 "," SX863A "manufactured by Nippon Synthetic Rubber Co., Ltd.," Boncoat "manufactured by Dainippon Ink and Chemicals," Grandall PP-1000 "," Grandall PP-1001 "," Grandall PP ". -200
0 "," latex SBL8801 "manufactured by Asahi Kasei, etc. can be appropriately selected and used. The material of the hollow particles preferably used in the present invention is polyester resin. Here, the polyester resin is obtained by a polycondensation reaction of polyvalent carboxylic acids and polyhydric alcohols like the polyester resin used for the colored particles. Hollow fine particles of polyester resin are obtained by following the same procedure as for colored fine particles (however, in this case, it does not have to be colored, but it does not deny that they are colored) 1) A method of heat-treating at a glass transition temperature or higher in an aqueous medium having a low ionic strength, 2) adding a water-soluble organic compound to an aqueous dispersion of ionic group-containing polyester resin particles, and then azeotropically treating the water-soluble organic compound Method of hollowing when removing, 3) adding a solvent to the aqueous dispersion of ionic group-containing polyester resin particles, a method of hollowing when dried by a method such as spray drying after swelling the particles, And the like, and the polyester hollow particles thus obtained can be used.

In the present invention, it is most preferable to use a method in which heat treatment is performed at a temperature not lower than the glass transition temperature in an aqueous medium having a low ionic strength. According to this method, the temperature of heat treatment and the ionic strength (electric field) The hollowness can be controlled arbitrarily depending on the material concentration). The treatment temperature is preferably a temperature between the glass transition temperature of the polyester resin and 200 ° C, more preferably 140 ° C or lower, further preferably 100 ° C or lower, and further preferably 90 ° C or lower. The electrolyte concentration is preferably 0.2 mol / l or less, more preferably 0.1 mol / l or less, and even more preferably 0.05 mol / l for monovalent ions.
The following is more preferable. It is also possible to obtain hollow particles from a polyester resin having an unsaturated bond in advance and swell and crosslink with a vinyl polymerizable monomer to obtain hollow particles made of a crosslinked polyester resin.

In the present invention, both colored polyester fine particles and hollow synthetic resin fine particles are essential components, and the content thereof is 0.1-40 wt% of colored polyester fine particles and 0.5-15 wt% of hollow synthetic resin fine particles. Essential, colored polyester fine particles 2-40 wt%, hollow synthetic resin fine particles 1
10% by weight is preferable, and colored polyester fine particles 5
40 wt% and 2 to 8 wt% of hollow synthetic resin fine particles are more preferable, and 10 to 30 wt% of colored polyester fine particles and 2 to 8 wt% of hollow synthetic resin fine particles are still more preferable. The balance is preferably an aqueous medium. In the present invention, it is preferable to satisfy the relationship of “particle diameter of colored polyester resin fine particles ≦ particle diameter of hollow synthetic resin fine particles”. 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, 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 contained in an aqueous medium of 50
It can be appropriately added within a range not exceeding%. 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 in order to reduce 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, it is preferable to use at least one UV absorber selected from benzotriazole type, benzophenone type, and benzosalicylate type. The content of these antioxidants is 0.01 to 5.0% by weight, preferably 0.02 to 1.0% by weight, and more preferably 0.05 to 0.5% by weight, based on the polyester resin.

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 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 hollow 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 which is apt to cause bleeding. 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 hollow synthetic resin fine particles is It was made as a result of finding that the purpose was satisfied.

In the present invention, the specific gravity of the resin and the particle size of the dispersed particles are defined 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 hollow 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 colored polyester fine particle component that permeates and diffuses along with the medium (water) along the fibers of the recording paper is suppressed by the added hollow synthetic resin fine particles, so that bleeding is suppressed and It can be understood that a relatively large amount remains in the vicinity of the surface. This effect is conspicuously observed particularly in the hollow 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 cyclohexanedicarboxylic acid dimethyl ester, 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. Keeping the temperature at 200 ° C, add 4 parts by weight of trimellitic anhydride and react for 60 minutes to prepare a copolyester resin (A2).
I got The obtained copolyester resin has an average molecular weight of 3500, an acid value of 214 eq./ton and a glass transition temperature of 7.
It was 0 ° C.

[Preparation 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. Then, 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. It was distilled until it 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 average particle size of the finely dispersed particles present in the obtained polyester aqueous dispersion was 0.22 μm,
The cell potential was -55 mV.

[Preparation of Hollow Polyester Particles] Thermometer,
In an autoclave equipped with a stirrer, terephthalic acid dimethyl ester 80 parts by weight, isophthalic acid dimethyl ester 80 parts by weight, 5-sodium sulfoisophthalic acid dimethyl ester 6 parts by weight ethylene glycol 68 parts by weight, neopentyl 114 parts by weight of glycol and 0.1 parts by weight of tetrabutoxytitanate were charged and heated at 120 to 220 ° C. for 120 minutes to carry out a transesterification reaction. Then, set the temperature of the reaction system to 180 ° C.
20 parts by weight of fumaric acid and 0.1 parts by weight of hydroquinone were added, and the reaction was continued at 200 ° C. for 60 minutes, after which the temperature of the reaction system was raised to 220 to 240 ° C. and the system pressure was 1 to 1
As a result of continuing the reaction at 0 mmHg for 60 minutes, a copolyester resin (A) was obtained.

The copolymerized polyester resin thus obtained had a number average molecular weight of 2,800 and a sodium sulfonate group equivalent of 118.
eq./ton, glass transition temperature was 54 ° C. thermometer,
200 parts by weight of polyester resin (A), 200 parts by weight of methyl ethyl ketone, and 100 parts by weight of tetrahydrofuran were charged into a four-necked 10 liter separable flask equipped with a condenser and stirring blades and dissolved at 70 ° C. Then, 500 parts by weight of ion-exchanged water at 70 ° C. was added. In the system, phase inversion self-emulsification occurred and an aqueous dispersion was produced. Further, it was distilled in a distillation flask until the distillate temperature reached 103 ° C., and after cooling, water was added to obtain a polyester aqueous dispersion (B) having a solid content concentration of 25%. The average particle size of the finely dispersed particles present in the obtained polyester aqueous dispersion is 0.31μ.
m, the zeta potential was -59 mV, and the particle shape by SEM observation was almost spherical and solid.

An aqueous dispersion of the obtained particles was used as an artificial kidney (AK
H) A module [manufactured by Toyobo Co., Ltd.] was used to carry out dialysis washing until the electric conductivity on the filtrate side reached 10 μS / cm, and finally an aqueous dispersion of polyester resin particles having a nonvolatile content of 10 wt% was obtained with ion-exchanged water. It was The obtained aqueous dispersion was charged into a stainless pot of a dyeing tester Mini Color [made by Texum Giken Co., Ltd.], heated to 130 ° C. at a temperature rising rate of 3 ° C./minute, and then kept at 130 ° C. for 60 minutes and then at room temperature. Water cooled until. The particles present in the aqueous dispersion after the treatment were hollow particles having many cavities inside. The obtained aqueous dispersion was diluted with deionized water to prepare a polyester particle aqueous dispersion having a solid content concentration adjusted to 5%. 1000 parts by weight of the aqueous dispersion was placed in a separable flask, and while gently stirring, 50 parts by weight of distilled styrene in which 1% by weight of benzoyl peroxide was dissolved was added dropwise and stirring was continued for 30 minutes.
The temperature was raised to ℃ and the reaction was continued for 300 minutes. The system was cooled to room temperature. The particles present in the obtained aqueous dispersion have a particle size of about 0.
The particles were hollow particles (C) having a diameter of 45 μm and a hollow ratio of 54 vol%.

[0047]

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) (non-volatile content) 15.0 wt% Ethylene glycol 4.0 wt% Ethyl alcohol 1.0 wt% Hollow cross-linked polyester fine particles (C) (non-volatile content) 5.0 wt% Water residue Hollow cross-linked polyester The fine particles (C) have an average particle size of 0.45 μm, a hollow ratio of 33 vol%, and an apparent specific gravity of 1.12. (When water occupies the inside of the cavity). 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.

The viscosity of the recording material was adjusted to 2.8 centipoise and the surface tension was adjusted to 58 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 50 to 60 dyn / cm. Was adjusted to. 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, and the minimum film-forming temperature was measured by an ordinary method. 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 crow mouth, 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. Further, a trial recording medium was filled in a test tube having a depth of 10 cm, sealed and allowed to stand for 3 months, and after 3 months, the storage stability was evaluated by the presence or absence of a precipitate at the bottom of the test tube. The results are shown in Table 1.
Shown in

[Table 1] Table 1. Medium 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 ×.

[0049]

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 Content) 15.0 wt% Isopropyl Alcohol 0.8 wt% Nitriletriethanol 0.2 wt% Hollow Particles OP-84J (Nonvolatile Content) 5.0 wt% Remains Hollow Particles OP-84J Is a copolymer resin hollow particle water dispersion consisting of styrene-acrylic copolymer,
Lowpaque OP-84J [Rohm and Haas Company]
Is marketed as. Average particle diameter 0.55 μm Hollow ratio 26 vol% Minimum film forming temperature 150 ° C. Apparent specific gravity 1.04. This resin did not dissolve in methanol, ethanol, ethylene glycol, and nitrile triethanol, but swelling was slightly observed in methanol and isopropanol. 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 10 ° C. when 1 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.

[0050]

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 Content) 15.0 wt% Ethylene Glycol 5.0 wt% Isopropyl Alcohol 1.0 wt% HP-91 (Nonvolatile Content) 5.0 wt% Water Residue Hollow particles HP-91J are styrene A copolymer resin hollow particle water dispersion comprising an acrylic copolymer,
Lowpaque OP-84J [Rohm and Haas Company]
Is marketed as. Average particle diameter 1.0 μm Hollow ratio 51 vol% Minimum film forming temperature 150 ° C. Apparent specific gravity 1.02. This resin did not dissolve in methanol, ethanol, ethylene glycol, and nitrile triethanol, but swelling was slightly observed in methanol and isopropanol. 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 10 ° C. when 1 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 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) (non-volatile content) 15.0 wt% propylene glycol 5.0 wt% butanol 0.8 wt% nitrile triethanol 0.2 wt% citric acid 0.1 wt% SX863A (non-volatile content) 2.0 wt% water Residue SX863A is a copolymer resin hollow particle water dispersion made of a crosslinked styrene-acrylic copolymer, and is commercially available from [Nippon Synthetic Rubber Co., Ltd.]. The average particle diameter is 0.50 μm, the hollow ratio is 34 vol%, the minimum film forming temperature is> 150 ° C., and the apparent specific gravity is 1.04. This resin did not dissolve in methanol, ethanol, isopropanol, ethylene glycol, or nitrile triethanol and did not swell. Even when 10 parts by weight of isopropyl alcohol was added to 100 parts by weight of the aqueous dispersion prepared to have a nonvolatile concentration of 20% by weight, the minimum film forming temperature was> 150 ° C., and it was judged that the swelling property was virtually absent.

[0052]

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% Gandall PP-2000 (Nonvolatile Content) 2.0 wt% Water Residue Glandol PP-2000 is a crosslinked styrene-acrylic type It is a copolymer resin hollow particle water dispersion of a copolymer, which is commercially available from Dainippon Ink and Chemicals. Average particle diameter 0.35 μm Hollow ratio 34 vol% Minimum film forming temperature> 150 ° C. Apparent specific gravity 1.02. This resin did not dissolve in methanol, ethanol, isopropanol, ethylene glycol, or nitrile triethanol and did not swell. Even when 10 parts by weight of isopropyl alcohol was added to 100 parts by weight of the aqueous dispersion prepared to have a nonvolatile concentration of 20% by weight, the minimum film forming temperature was> 150 ° C., and it was judged that the swelling property was virtually absent.

[0053]

Example 6 A colored recording material (6) was prepared by replacing the colored polyester fine particles (B1) in Example 1 with (B2).

[0054]

Example 7 The coloring agent fine particles (B1) in Example 4 were replaced with (B2) to obtain a recording material (7).

[0055]

Example 8 The colored polyester fine particles (B1) in Example 5 were replaced with (B2) to obtain a recording material (8). The following evaluation was performed in the same manner. The results are shown in Table 1. Shown in

[0056]

[Example 9] 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 colored polyester fine particles, a recording liquid of four colors was prepared according to the formulation of Example 1. 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.

[0057]

Comparative Example 1 A recording agent (9) 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.

[0058]

Comparative Example 2 A recording agent (10) having the following composition was prepared by 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

[0059]

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.

[0060]

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 colored resin particles which can be suitably used as a 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] 0025

[Correction method] Change

[Correction content]

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 phase inversion self-emulsification method.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

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 recording agent, and a range of about 0.01 μm is acceptable. However, the upper limit of the particle size distribution is about 10 μm, preferably 5 μm.
m, more preferably 3 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. The specific gravity of the resin constituting the hollow particles of the present invention is not particularly limited, but preferably in the range of 0.9 to 1.3,
The range is preferably 0.95 to 1.10, more preferably 0.93 to 1.00, and further preferably 0.94 to 0.98. In the present invention, it is preferable that the hollow particles are substantially filled with water. More precisely, it is preferable that the inside of the cavity is filled with an aqueous dispersion medium which is a dispersion medium of the present colored fine particle water dispersion. Such cavities are substantially filled with air after the recording material has been printed on the paper and dried.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

The hollow resin fine particles are preferably non-swelling with respect to the water-soluble organic compound as an additive, lower alcohol and / or alkylene glycol and / or alkanolamines. The term "non-swelling" means that the resin does not dissolve in the organic compound as a physical property as a bulk, and the organic compound is 20
wt%, preferably 10 wt%, more preferably 5 wt%
The above means that the resin does not absorb, and from another viewpoint, in an aqueous dispersion of such resin particles, 1
It means that the film forming temperature does not decrease by 0 ° C. or higher, preferably 5 ° C. or higher. From another point of view, it means that the presence of such a water-soluble organic compound does not cause an effective change in the particle shape in the region of the resin softening temperature or below the glass transition temperature. When swelling to these water-soluble organic compounds that are supplementarily added to the recording agent, dry film formation of resin particles occurs at the tip of the pen, which causes clogging of the pen, and is of course essential for the present invention. The required form of the hollow particles cannot be maintained, and the effect of the present invention disappears.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

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 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 hollow 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 which is apt to cause bleeding. 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 concern only the recording quality, and do not give any consideration to the storage stability of the recording agent itself and the reliability of the pen tip against clogging. 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 hollow synthetic resin fine particles is It was made as a result of finding that the purpose was satisfied.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Delete

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction content]

[0060]

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.

Front page continued (72) Inventor Yozo Yamada 1-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd.

Claims (8)

[Claims] 1. 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) Average outer particle diameter is 0.1. 1 to 2.0 μm and 0.5 to 15% by weight of hollow synthetic resin fine particles having cavities inside
An aqueous dispersion of colored fine particles containing as an essential component. 2. The colored particle water dispersion according to claim 1, wherein in the resin particles having a cavity inside, the cavity is substantially filled with water. 3. The aqueous dispersion of colored fine particles according to claim 1, wherein the resin fine particles having voids therein are non-swellable with respect to lower alcohols and / or alkylene glycols and / or alkanolamines at room temperature. 4. The aqueous dispersion of colored fine particles according to claim 1, wherein the resin fine particles having voids inside have a polyester resin as a main component. 5. The aqueous dispersion of colored fine particles according to claim 1, wherein the resin fine particles having voids inside are made of a resin component having a crosslinked structure. 6. The polyester resin has an ionic group of 2
The colored fine particle water dispersion according to claim 1, which is contained in the range of 0 to 2000 eq./ton. 7. The colored fine particle water dispersion according to claim 1, wherein the ionic group contained in the polyester resin is an organic amine salt of a carboxylic acid group. 8. The colored fine particle water dispersion according to claim 1, wherein the average particle diameter of the polyester resin fine particles is in the range of 0.01 to 0.2 μm.