JP2014125494A - Metal-oxide-containing aqueous dispersion of fine particle of epoxy resin cured product and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispersion of a fine resin particle which has excellent storage stability and can contain a metal oxide in a wide concentration range and its industrially advantageous production method.SOLUTION: An aqueous dispersion comprises (A) a fine particle of an epoxy resin cured product and (B) a metal oxide. An amount of unreacted epoxy resin in (A) the fine particle of the epoxy resin cured product is 0-30 mass%, and the average particle size of (A) the fine particle of the epoxy resin cured product is 0.05-100 μm. The aqueous dispersion is produced by adding a curing agent to an emulsion dispersed dropwise with an epoxy resin to harden an unreacted epoxy resin ingredient in a granular form to obtain (A1) a dispersion containing (A) the fine particle of the epoxy resin cured product and mixing (A1) the dispersion with (B) the metal oxide or (B1) a dispersion of the metal oxide.

Description

  The present invention relates to a metal oxide-containing aqueous dispersion of epoxy resin cured fine particles having excellent storage stability and a method for producing the same.

  Resin fine particle dispersions in which resin fine particles, which are made of resin and have a diameter ranging from several tens of nanometers to several hundreds of micrometers, are dispersed in a dispersion medium are widely used in paints, printing, adhesion, cosmetics, medicine, etc. Used in various fields. At this time, it is widely known to add a metal oxide as an additive in order to improve the characteristics of the resin fine particle dispersion. In this case, the metal oxide content is generally equal to or less than the resin fine particle content.

  On the other hand, fine ceramic thin films are used in many fields such as antireflection films, cut filters for infrared sensors, cut filters for X-ray sensors, and bandpass filters for medical analyzers in optical applications. Such a fine ceramic thin film can be obtained by applying a dispersion in which a metal oxide is dispersed in a liquid onto a support by a technique such as printing or coating, and firing the dispersion. As one method for improving the light scattering property of the antireflection film, it is conceivable to mix resin fine particles having a refractive index different from that of the metal oxide. In such applications, a resin fine particle dispersion containing a high concentration of metal oxide is required so that the metal oxide content is equal to or greater than the resin particle content.

  Examples of the resin fine particle dispersion containing the metal oxide as described above include Patent Documents 1 and 2. However, in any of the dispersions, the content of the metal oxide is 1/3 or less of the resin fine particle content, and the stable resin fine particle content is equal to or more than the resin fine particle content. The method for obtaining the dispersion is not substantially disclosed.

JP 2003-327918 A JP 2007-112864 A JP 2011-74208 A

  An object of the present invention is to provide a resin fine particle dispersion which is excellent in storage stability and can contain a metal oxide in a wide range of concentrations, and an industrially advantageous production method thereof.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by using, as resin fine particles, cured epoxy resin fine particles having an unreacted epoxy resin content of 30% by mass or less in the particles. The present invention has been reached.

That is, the present invention
[1] Epoxy resin cured product fine particles (A) (hereinafter sometimes simply referred to as “particles (A)”) and an aqueous dispersion containing a metal oxide (B), the epoxy resin cured product fine particles (A) The amount of unreacted epoxy resin in (A) is 0 to 30% by mass, and the average particle size is 0.05 to 100 μm. The metal oxide-containing aqueous dispersion of cured epoxy resin particles,
[2] When the mass of the metal oxide (B) in the aqueous dispersion is W1, and the mass of the cured epoxy resin fine particles (A) is W2, the relationship of 0.01 ≦ W1 / W2 ≦ 100 is satisfied. A metal oxide-containing aqueous dispersion of cured epoxy resin particles according to [1],
[3] The metal oxide-containing aqueous dispersion of epoxy resin cured particles according to [1] or [2], wherein the glass transition temperature of the cured epoxy resin particles (A) exceeds 50 ° C.,
[4] The epoxy resin cured fine particles (A) are epoxy resin cured fine particles obtained by curing a bifunctional epoxy resin with a curing agent, and the epoxy according to any one of [1] to [3] Metal oxide-containing aqueous dispersion of cured resin fine particles,
[5] The metal oxide-containing aqueous dispersion of cured epoxy resin particles according to any one of [1] to [4], wherein the curing agent is an amine-based curing agent,
[6] After adding a curing agent to the emulsion in which the epoxy resin is dispersed in the form of droplets, the unreacted epoxy resin component is cured into particles, and obtaining a dispersion liquid (A1) containing fine particles of the cured epoxy resin (A) The dispersion resin (A1) and the metal oxide (B) or metal oxide dispersion (B1) are mixed, and the metal of the epoxy resin cured product fine particles according to any one of [1] to [5] Production method of oxide-containing aqueous dispersion,
It is.

  The metal oxide-containing aqueous dispersion of the epoxy resin cured product fine particles of the present invention (hereinafter sometimes simply referred to as “water dispersion”) has a wider concentration than the conventional metal oxide-containing aqueous dispersion of resin fine particles. It can contain a metal oxide and has excellent storage stability. As a result, the metal oxide-containing aqueous dispersion of the epoxy resin cured fine particles of the present invention is a paint, an abrasive, an organic filler of a composite resin, an adhesive, a solid lubricant, a lubricant, a release agent, a cosmetic, a fine ceramic thin film. It is useful for various industrial uses.

  Hereinafter, the present invention will be described in more detail.

  The epoxy resin cured aqueous dispersion of fine particles of cured epoxy resin in the present invention has an unreacted epoxy resin content in the particles of 0 to 30% by mass and an average particle size of 0.05 to 100 μm. The product fine particles (A) and the metal oxide (B) are contained.

  Here, the unreacted epoxy resin is an epoxy resin that is a raw material for producing fine particles of cured epoxy resin in which no epoxy group in the molecule has reacted.

  The amount of the unreacted epoxy resin in the cured epoxy resin fine particles (A) in the present invention is preferably in the range of 0 to 30% by mass from the viewpoint of the storage stability of the aqueous dispersion. More preferably, it is 0-25 mass%, More preferably, it is 0-20 mass%, Especially preferably, it is 0-15 mass%, Most preferably, it is 0-10 mass%, The very preferable range is 0-5 % By mass. When the amount of the unreacted epoxy resin exceeds 30% by mass, the resin fine particles are easily bonded to each other, and the storage stability may be deteriorated.

  The amount of unreacted epoxy resin in the present invention is a value measured by a known technique (for example, Patent Document 3) as follows.

  In order to analyze the amount of the unreacted epoxy resin, particles and acetonitrile are mixed so that the particle concentration is 20% by mass or less, heated and stirred at 50 ° C. for a predetermined time, and then the particles are separated by filtration. Thus, a filtrate from which unreacted epoxy resin has been extracted is obtained, and the amount of unreacted epoxy resin in the particles can be determined by measuring the concentration of the epoxy resin in the filtrate. The heating and stirring time may be arbitrarily selected as long as the extraction amount becomes constant while the extraction amount of the unreacted epoxy resin is confirmed every few hours under the conditions.

  About the measuring method of an unreacted epoxy resin density | concentration, a high performance liquid chromatography (HPLC) analysis may be performed and quantified by the absolute calibration curve method as shown below. Specifically, first, the elution time when the epoxy resin, which is a raw material for producing the cured epoxy resin particles, is measured using HPLC is confirmed. Next, a calibration curve is created from the relationship between the samples containing only some epoxy resins having different concentrations and the area on the HPLC analysis chart obtained therefrom. Subsequently, the filtrate from which the unreacted epoxy resin has been extracted is subjected to HPLC analysis, and the peak area corresponding to the elution time of the raw material epoxy resin is determined. Finally, the amount of unreacted epoxy resin in the filtrate is calculated from a calibration curve prepared in advance, and the epoxy resin cured by [the amount of unreacted epoxy resin in the filtrate ÷ the amount of fine particles of cured epoxy resin used for extraction × 100]. Converted to the amount (% by mass) of unreacted epoxy resin in the product fine particles (A).

  When the particle size is small and filtration is difficult, the amount of unreacted epoxy resin can be quantified by separating the particles and the medium by centrifugation and using the medium as a sample.

  The average particle diameter of the cured epoxy resin fine particles (A) in the present invention is preferably in the range of 0.05 to 100 μm. A more preferred upper limit is 50 μm or less, still more preferably 10 μm or less, and a particularly preferred upper limit is 5 μm or less. Further, a more preferable lower limit is 0.1 μm or more, further preferably 0.15 μm or more, and a particularly preferable lower limit is 0.2 μm or more. If the average particle diameter of the cured epoxy resin particles is less than 0.05 μm, it is difficult to produce efficiently. On the other hand, if the average particle diameter of the cured epoxy resin particles exceeds 100 μm, precipitation tends to occur when the dispersion liquid is formed.

  Further, the particle size distribution index may be appropriately adjusted within a preferable range depending on the application.

  For example, in order to reduce the viscosity of the paint, the particle size distribution index is preferably 2.0 or more, and more preferably 5.0 or more. When used as a spacer for manufacturing an electronic component such as a liquid crystal display, the particle size distribution index is preferably 2.0 or less, more preferably 1.5 or less, still more preferably 1.2 or less, Particularly preferably, it is 1.1 or less. The preferred lower limit is 1.0.

  In addition, the average particle diameter of the cured epoxy resin fine particles (A) in the present invention is calculated by specifying an arbitrary 100 particle diameters from a scanning electron microscope or a transmission electron microscope photograph and obtaining the arithmetic average thereof. be able to.

  In the photograph, when the shape is not a perfect circle, that is, when it is oval, the maximum diameter of the particle is taken as the particle diameter. In order to accurately measure the particle size, it is measured at a magnification of at least 5000 times, preferably 10,000 times or more.

  Samples for electron microscope observation are taken out of the aqueous dispersion with the epoxy resin cured fine particles (A) by known separation techniques such as centrifugation and filtration using filter paper or filters, and reslurry washing is performed as necessary. Thereafter, the solvent is removed by a known drying technique such as heat drying or freeze drying.

  The particle size distribution index was calculated based on the following numerical conversion formula for the individual particle diameter values obtained above.

  Here, Di: particle diameter of individual particles, n: number of measurements (100), Dn: number average particle diameter, Dv: volume average particle diameter, PDI: particle diameter distribution index.

  The glass transition temperature of the cured epoxy resin fine particles (A) in the present invention preferably exceeds 50 ° C. from the viewpoint of storage stability. More preferably, it is 55 ° C. or higher, more preferably 60 ° C. or higher. When the glass transition temperature is 50 ° C. or lower, the resin fine particles are likely to coalesce and storage stability may be deteriorated. Although there is no restriction | limiting in particular about an upper limit, What is necessary is just to adjust suitably to a preferable range with a use.

  In addition, the glass transition temperature in this invention is a value measured as follows.

<Glass transition temperature>
Using a differential scanning calorimeter (DSC, for example, Seiko Instruments robot DSC), under a nitrogen atmosphere, a temperature range from 0 ° C. to a temperature exceeding 30 ° C. above the expected glass transition temperature of the polymer, Obtained when the temperature is raised once at a rate of 20 ° C./minute and held for 1 minute, then lowered to 0 ° C. at 20 ° C./minute, held for 1 minute, and then heated again at 20 ° C./minute. In the obtained DSC curve, the temperature at the point where the straight line equidistant in the vertical axis direction from the extended straight line of the low-temperature side and high-temperature side baselines and the curve of the step-like change portion of the glass transition was defined as the glass transition temperature.

  The DSC curve here is a differential scan in which the vertical axis represents the difference in thermal energy input per unit time applied to the test piece and the reference material so that the temperatures are equal, and the horizontal axis represents the temperature. It refers to the curve drawn in calorimetry.

  The fine particles of the cured epoxy resin applied to the present invention may be particles that are obtained by reacting at least an epoxy resin and a curing agent. As an epoxy resin, if it has two or more epoxy groups in a molecule | numerator, it will not specifically limit, All the things which have 65-2000 as an epoxy equivalent (mass of resin containing 1 equivalent of epoxy groups) are used. can do. Specific examples thereof include, for example, bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, Biphenyl type epoxy resin, stilbene type epoxy resin, hydroquinone type epoxy resin, naphthalene skeleton type epoxy resin, tetraphenylolethane type epoxy resin, trishydroxyphenylmethane type epoxy resin, dicyclopentadienephenol type epoxy resin, 3,4-epoxy Alicyclic epoxy resins such as cyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate and vinylcyclohexene diepoxide, bisphenol Epoxy resin with hydrogenated aromatic core such as A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, bisphenol S type epoxy resin, phthalic anhydride type epoxy resin, trisphenol alkane type epoxy resin, bisphenol A ethylene Diglycidyl ether of oxide adduct, diglycidyl ether of bisphenol A propylene oxide adduct, cyclohexanedimethanol diglycidyl ether, polyglycidyl ether of aliphatic polyhydric alcohol, diglycidyl ester of hexahydrophthalic anhydride, etc. Examples include polyglycidyl esters. These compounds can be used alone or in admixture of two or more. Of these, a bifunctional epoxy resin is preferable because the cross-linked structure does not become too strong, and both storage stability and film formability can be achieved. Among these, bisphenol A type epoxy resins are particularly preferable because they are most widely used.

  In addition, the epoxy resin has a glycidyl ether having one epoxy group such as alkyl glycidyl ether such as butyl glycidyl ether and lauryl glycidyl ether, phenyl glycidyl ether, and cresyl glycidyl ether as long as the effects of the present invention are not impaired. Etc. can be mixed and used. These compounds can be used alone or in admixture of two or more.

  Commercially available epoxy resins include “jER” (registered trademark) 827 (bisphenol A type epoxy resin), “jER” (registered trademark) 828 (bisphenol A type epoxy resin), “jER” (registered trademark) 806 (bisphenol F). Type epoxy resin), "jER" (registered trademark) 807 (bisphenol F type epoxy resin) "jER" (registered trademark) 152 (phenol novolac type epoxy resin), "jER" (registered trademark) 154 (phenol novolac type epoxy resin) (Epoxylon (registered trademark) 850 (bisphenol A type epoxy resin), "Epiclon" (registered trademark) 830 (bisphenol F type epoxy resin) "Epiclon" (registered trademark) ) N-740 (phenol novolac type epoxy resin) ( Above, manufactured by DIC Corporation), “Epototo” (registered trademark) YD128 (bisphenol A type epoxy resin) (manufactured by Tohto Kasei Co., Ltd.), “jER” (registered trademark) YX8000 (manufactured by Mitsubishi Chemical Corporation), “Denacol” (registered trademark) EX-252 (manufactured by Nagase ChemteX Corporation), “Lika Resin” (registered trademark) HBE-100 (manufactured by Shin Nippon Chemical Co., Ltd.), “Santo Tote” (registered trademark) ST-3000 (Manufactured by Nippon Steel Chemical Co., Ltd.), “ADEKA RESIN” (registered trademark) EP-4080 (manufactured by ADEKA Co., Ltd.), SR-HBA (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) (above, hydrogenated bisphenol A type epoxy Resin) and the like are commercially available.

  Although it does not specifically limit as a hardening | curing agent, The aliphatic amine normally used as a hardening | curing agent of an epoxy resin, an alicyclic amine, an aromatic amine, a polyamidoamine, a carboxylic acid anhydride, a Lewis acid complex, an acid type curing catalyst, a base And a system curing catalyst. Of these, amine curing agents are preferable from the viewpoint of reaction rate, and aliphatic amines, alicyclic amines, and polyamide amines are particularly preferable.

  Specific examples of the aliphatic amine include hydrazine, hexane diacid azide, ethylene diamine, trimethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, 2-methyl-1,5-diaminopentane, and N-hexyltri. Methylenediamine, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, tetraethylenepentamine, dipropyleneamine, triethylenediamine, polyamidoamine, octylamine, laurylamine, myristylamine, stearylamine, cocoalkylamine, tallow alkylamine, oleylamine, Examples thereof include hardened tallow alkylamine, N, N-dimethyllaurylamine, N, N-dimethylmyristylamine and the like.

  Specific examples of the alicyclic amine include 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 4,4′-methylenebis (cyclohexylamine), 4,4 ′. -Methylenebis (2-methylcyclohexylamine), 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, mensendiamine, piperidine, piperazine, 2-methylpiperazine, N, N -Dimethylpiperazine, N- (2-aminoethyl) piperazine, 4,4'-trimethylenedipiperazine, 4-hydroxypiperazine, 4-aminomethylpiperazine, 1- [4- (3-aminopropylamino) butyl] piperazine Or 4-amino-2,2,6,6-tetramethylpi Lysine, and the like.

  Specific examples of aromatic amines include diaminodiphenyl sulfone and diaminodiphenylmethane.

  Among these, preferably piperazine, 2-methylpiperazine, N, N-dimethylpiperazine, N- (2-aminoethyl) piperazine, 4,4′-trimethylenedipiperazine, 4-hydroxypiperazine, 4-aminomethylpiperazine, 1- [4- (3-aminopropylamino) butyl] piperazine, 4-amino-2,2,6,6-tetramethylpiperidine, hydrazine, hexanedioic acid dihydrazide, ethylenediamine, trimethylenediamine, tetramethylenediamine, penta Methylenediamine, hexamethylenediamine, 2-methyl-1,5-diaminopentane, N-hexyltrimethylenediamine, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, 1,3-bis (aminomethyl) cyclohexane, 1,4 Bis (aminomethyl) cyclohexane, 4,4′-methylenebis (cyclohexylamine), 4,4′-methylenebis (2-methylcyclohexylamine), 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4 -Cyclohexanediamine, isophoronediamine, mensendiamine, diaminodiphenylsulfone and diaminodiphenylmethane. Particularly preferably, piperazine, N- (2-aminoethyl) piperazine, ethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-cyclohexanediamine, 1,4 -Cyclohexane diamine, isophorone diamine, mensen diamine.

  Commercially available curing agents include triethylenetetramine, diethylenetriamine, aliphatic amine type (“jER Cure (registered trademark)” (manufactured by Japan Epoxy Resin Co., Ltd.)), polyoxyalkyleneamines (“Jeffamine ( Registered trademark) ”(manufactured by Mitsui Chemicals Fine Co., Ltd.), polyamidoamines (“ Rakkamide ”(registered trademark) (manufactured by Dainippon Ink Industries, Ltd.)), polyalkylene polyamine-based amidoamines (“ polyamide ” (Registered trademark) (manufactured by Sanyo Chemical Industries, Ltd.).

  Furthermore, these curing agents can be used in combination with an appropriate curing aid in order to increase the curing activity within a range not impairing the effects of the present invention. Preferred examples of the case where a curing aid is combined with an epoxy resin include an example of combining dicyandiamide with a urea derivative such as 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) as a curing aid, Examples include combining a group 3 amine with a boron trifluoride ethylamine complex as a curing aid, and combining a tertiary amine with a carboxylic acid anhydride or a novolac resin as a curing aid.

  The fine particles of cured epoxy resin applied to the present invention may contain other polymers as its constituent components. Examples of polymer components include, but are not limited to, polyamide resins, styrene resins, vinyl resins, polyester resins, aromatic polysulfone resins, aromatic polyethersulfone resins, and the like. . The constituent ratio of the cured epoxy resin particles of these polymers is preferably 95% by mass or less. When it is more than 95% by mass, functions such as heat curing performance and adhesion performance, which are the performance of the original epoxy resin, tend to be insufficient. More preferably, it is 90 mass% or less. Although there is no restriction | limiting in particular as a minimum, It is preferable that it is 5 mass% or more from a viewpoint of fully exhibiting the characteristic of a polymer.

  Examples of the metal oxide (B) applied to the present invention include titanium oxide, zinc oxide, tungsten oxide, antimony oxide, niobium oxide, indium oxide, barium titanate, strontium titanate, aluminum oxide, chromium oxide, manganese oxide, Known metal oxides such as molybdenum oxide, vanadium oxide, tin oxide, zirconium oxide, potassium oxide, bismuth oxide, tantalum oxide, and iron oxide (including magnetic iron oxide) can be mentioned. These oxides can be used alone or in combination of two kinds. The above can be mixed and used suitably.

Although it does not specifically limit as a shape of a metal oxide (B), A particulate form is preferable. Here, the particulate shape includes a spherical shape, an ellipsoidal shape, a red blood cell shape, a shape of a granulated product in which spherical or ellipsoidal particles are aggregated, and an irregularly crushed shape or a shape of the granulated product. It is done.
The average particle diameter of the metal oxide (B) may be appropriately adjusted within a preferable range depending on the use, but is generally preferably 3 to 500 nm, and a more preferable upper limit is 300 nm or less, and a more preferable upper limit is 100 nm or less. When the average particle size is 3 nm or more, the total interface free energy between the metal oxide (B) and the medium becomes small, and the dispersion of the metal oxide (B) becomes easy. Furthermore, synthesis of the metal oxide (B) becomes easy, and cost reduction can be expected. If the average particle diameter exceeds 500 nm, precipitation tends to occur when the dispersion is made.
In addition, the average particle diameter of the metal oxide (B) in the present invention can be calculated by specifying an arbitrary 100 particle diameters from a scanning electron microscope or a transmission electron microscope photograph and obtaining the arithmetic average thereof. it can.

  In the photograph, when the shape is not a perfect circle, that is, when it is oval, the maximum diameter of the particle is taken as the particle diameter. In order to accurately measure the particle size, it is measured at a magnification of at least 10,000 times, preferably at least 50,000 times.

  Samples for observation under an electron microscope are obtained after taking out the metal oxide (B) from the aqueous dispersion and performing reslurry washing or the like as required by a known separation technique such as centrifugation or filtration using filter paper or a filter. It is produced by removing the solvent by a known drying technique such as heat drying or freeze drying.

  The aqueous dispersion of the present invention may contain a surfactant component. Examples of the surfactant include a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant. Examples of the anionic surfactant include fatty acid sodium, fatty acid potassium, and alkylbenzene. Sodium sulfonate, sodium alkyl sulfate, sodium alkyl sulfonate, sodium alkyl ether sulfate, monoalkyl phosphate, sodium polyoxyethylene alkyl ether phosphate, sodium fatty acid ester sulfonate, sodium fatty acid ester sulfate, fatty acid alkyl Examples include sodium rosamide sulfate and sodium fatty acid amide sulfonate. Examples of the cationic surfactant include alkyl methyl ammonium chloride, alkyl trimethyl ammonium chloride, dialkyl dimethyl ammonium chloride, alkyl dimethyl benzyl ammonium chloride, and alkyl pyridinium chloride. Examples of zwitterionic surfactants include alkylaminocarboxylates, carboxybetaines, alkylbetaines, sulfobetaines, phosphobetaines, and the like. Nonionic surfactants include sucrose fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene lanolin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycol monofatty acid ester, fatty acid alkanolamide, fatty acid monoethanolamide. , Fatty acid diethanolamide, fatty acid triethanolamide, polyoxyethylene fatty acid amide, isopropanolamide, alkylamine oxide, polyoxyethylene amine, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene styrenated phenyl ether and these And derivatives thereof.

  The alkyl referred to here includes, for example, straight-chain saturated hydrocarbon groups or branched saturated hydrocarbon groups having 1 to 30 carbon atoms. The alkyl moiety may be a hydrogen atom, a linear unsaturated hydrocarbon group, or a branched unsaturated hydrocarbon group. In particular, the surfactant used in the present invention is preferably a polyoxyethylene alkyl ether, a polyoxyethylene styrenated phenyl ether or a derivative thereof contained in the above. A preferable range of the alkyl group includes a straight-chain saturated hydrocarbon group or a branched saturated hydrocarbon group having 1 to 20 carbon atoms. The alkyl moiety may be a hydrogen atom, a linear unsaturated hydrocarbon group, or a branched unsaturated hydrocarbon group.

  Particularly preferred surfactants include those having the following structure.

  In the formula, m is a positive number of 1 to 3, and n is a positive number of 5 to 100, preferably 10 to 40.

  Since polyoxyethylene alkyl ether, polyoxyethylene styrenated phenyl ether and derivatives thereof have an appropriate HLB value for the fine particles of the cured epoxy resin, the dispersibility of the fine particles of the cured epoxy resin in the dispersion medium And the obtained dispersion can maintain long-term stable dispersibility.

  In addition, an organic binder resin may be added to the aqueous dispersion of the present invention for the purpose of adjusting the viscosity of the dispersion. Furthermore, the said organic binder resin has a role which assists dispersion | distribution of epoxy resin hardened material microparticles | fine-particles (A) and a metal oxide (B).

  The organic binder resin is not particularly limited, but is modified with polyvinyl alcohol acetal such as ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, polyethylene glycol, polyvinyl alcohol, polyvinyl butyral, gelatin, polyacrylic acid, polyacrylamide And dextrin. As for the said organic binder resin, only 1 type may be used and 2 or more types may be used together.

  The aqueous dispersion of the present invention contains the metal oxide (B) at a wide concentration in the aqueous dispersion due to the small interaction between the epoxy resin cured fine particles (A) and the metal oxide (B). can do. The content of the metal oxide may be appropriately adjusted within a preferable range depending on the application. In general, the mass of the metal oxide (B) is W1, and the epoxy resin cured fine particles in the epoxy resin cured fine particle dispersion liquid. When the mass of (A) is W2, it is preferable that the relationship of 0.01 ≦ W1 / W2 ≦ 100 is satisfied. If it is out of this range, one of the cured epoxy resin fine particles (A) and the metal oxide (B) becomes stronger, and the effects of the present invention may not be obtained.

  A preferable upper limit for expressing the characteristics of both particles in a balanced manner is 50 or less, more preferably 30 or less, and still more preferably 10 or less. Moreover, as a minimum, Preferably it is 0.1 or more, More preferably, it is 0.2 or more, More preferably, it is 0.3 or more.

  The aqueous dispersion of the present invention can be added with additives such as a colorant, an antioxidant, and a plasticizer, if necessary, as long as the effects of the present invention are not impaired. These additives may be previously contained in water to constitute the aqueous dispersion of the present invention, or may be added separately to the aqueous dispersion.

  Examples of the colorant include inorganic pigments, organic pigments, and dyes. Examples of inorganic pigments include white pigments, cobalt compounds, iron compounds, sulfides, and mixtures thereof. Organic pigments include azo pigments, polycyclic pigments, and mixtures thereof. As dyes, azo, anthraquinone, indigoid, sulfide, triphenylmethane, pyrazolone, stilbene, diphenylmethane, xanthene, alizarin acridine, quinoneimine, thiazole, methine, nitro, Examples thereof include nitroso, aniline, and mixtures thereof. Antioxidants are added for the purpose of scavenging radicals, so phenol-based antioxidants, sulfur-based antioxidants, aromatic amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, etc. Can be mentioned. Specific examples of these antioxidants include phenol, hydroquinone, p-methoxyphenol, benzoquinone, 1,2-naphthoquinone, cresol, catechol, benzoic acid, hydroxybenzoic acid, salicylic acid, hydroxybenzenesulfonic acid, 2,5-di -T-butylhydroquinone, 6-t-butyl-m-cresol, 2,6-di-t-butyl-p-cresol, 4-t-butylcatechol, 2,4-dimethyl-6-t-butylphenol, 2 -T-butylhydroquinone, 2-t-butyl-4-methoxyphenol and the like.

  The total content of the epoxy resin cured product fine particles (A) and the metal oxide (B) in the aqueous dispersion of the present invention is 5 to 100% by mass from the viewpoint of handling properties of the dispersion. 80% by mass is preferable, and a more preferable upper limit is 75% by mass or less, and a further preferable upper limit is 70% by mass or less. A more preferred lower limit is 10% by mass or more, and a more preferred lower limit is 15% by mass or more. If the total content exceeds 80% by mass, the fluidity of the dispersion may be insufficient. If the total content is less than 5% by mass, the viscosity of the aqueous dispersion may be too low, and it may be necessary to add a large amount of an organic binder resin or the like for viscosity adjustment.

  In 100% by mass of the aqueous dispersion of the present invention, the content of water as a dispersion medium is preferably 20 to 95% by mass, and a more preferable upper limit is 90% by mass or less, and a more preferable upper limit is 85% by mass. It is as follows. When the water content satisfies the above lower limit, the fluidity of the dispersion becomes appropriate and handling becomes easy. When the water content satisfies the above upper limit, the dispersion can be used efficiently while maintaining the handleability of the dispersion.

  When the aqueous dispersion of the present invention contains the organic surfactant, the content of the surfactant is such that the epoxy resin cured product fine particles (A), the metal oxide (B), the organic binder resin, and the additive It is appropriately selected depending on the concentration and type. In 100% by mass of the aqueous dispersion, the content of the surfactant is 0.5 to 30% by mass as an example of a preferred range.

  In the case where the aqueous dispersion of the present invention contains the organic binder resin, from the viewpoint of dispersion stability and handling properties of the aqueous dispersion, the content of the organic binder resin is 1 in 100% by mass of the aqueous dispersion. It is preferable that it is -30 mass%.

  Although it does not specifically limit about the density | concentration of an additive, The range of 0.001-10 mass% is preferable in 100 mass% of aqueous dispersions. The upper limit is more preferably 5% by mass or less, and most preferably 3% by mass or less. Moreover, as a preferable minimum, it is 0.02 mass% or more, and 0.05 mass% or more is the most preferable.

  Next, a method for obtaining a metal oxide-containing aqueous dispersion of fine particles of cured epoxy resin of the present invention will be described.

  The method for producing the aqueous dispersion of the present invention is not particularly limited, but if exemplified, a curing agent is added to the emulsion in which the epoxy resin is dispersed in a droplet form, and the epoxy resin component is cured into particles, A method for producing a dispersion liquid (A1) containing cured epoxy resin fine particles (A) and then mixing the dispersion liquid (A1) and a metal oxide (B) or metal oxide dispersion liquid (B1). Is mentioned.

Moreover, the following are illustrated as another aspect as a manufacturing method of the epoxy resin emulsion for obtaining the said dispersion liquid (A1). In the present invention, these methods are not particularly limited.
(1) A method in which an epoxy resin or a solution thereof is continuously discharged from a nozzle that vibrates in the air or in water to cut it into droplets and collect it in water.
(2) A method of discharging an epoxy resin or a solution thereof in a pulse form from an air or water nozzle and collecting it in water.
(3) A method of emulsifying an epoxy resin or a solution thereof with water containing a surfactant.
(4) A method of emulsifying an epoxy resin or a solution thereof with water containing a powder emulsifier.
(5) A method of emulsifying an epoxy resin or a solution thereof with water containing a protective colloidal substance.

  Among the above methods, the methods (3) to (5) are preferably used in the present invention from the viewpoint of productivity, but the combination of the methods (1) to (5) is also preferably used in the present invention.

  Although it does not specifically limit as surfactant in the said method, The above-mentioned cationic surfactant, anionic surfactant, zwitterionic surfactant, and nonionic surfactant can be used. Of these, nonionic surfactants are preferred from the viewpoint of emulsion stability. Surfactants can be used alone or in combination of two or more. These surfactants are added in an amount of about 0.5 to 30% by mass with respect to a mixture of epoxy resin and curing agent or a solution thereof.

  Moreover, as a powder emulsifier, there exists fine powder crystalline cellulose, barium sulfate powder, etc., and about 0.5-20 mass% is used.

  Examples of protective colloidal substances include polyvinyl alcohol, gum arabic, carboxymethylcellulose, gelatin, and sodium alginate, which are generally used in an amount of about 0.1 to 20% by mass dissolved in an aqueous dispersion medium. .

  Surfactant or powder emulsifier is added to the epoxy resin, and it is common to dissolve in water when adding protective colloidal material, but epoxy resin and surfactant, powder emulsifier or protection Depending on the compatibility of the colloidal substance, a surfactant or a powder emulsifier may be added by dissolving in water, or a protective colloidal substance may be added to the epoxy resin.

  As a method of emulsifying and dispersing an epoxy resin in water, a method of gradually adding water to a strongly stirred epoxy resin or a solution thereof, or a method of gradually adding an epoxy resin or solution thereof to a strongly stirred water is generally used. Is. When the viscosity of the epoxy resin or its solution is low, emulsification is possible by either method. However, when the viscosity is high, the former method, that is, the epoxy resin or its solution that is vigorously stirred, The method of gradually adding is recommended.

  Since the epoxy resin generally has a viscosity of 1 poise or more, it is preferable to take the former method.

  The mixing apparatus in this step may be any mixture that can provide the above emulsion. Considering efficient dispersion of a dispersed phase mainly composed of a high-viscosity epoxy resin in an aqueous phase, for example, a homomixer, a disperser, etc. It is preferable to use an apparatus having a strong shearing force such as

  The mixing temperature in the above step is not particularly limited and can be appropriately selected. However, it is preferably 10 to 90 ° C, more preferably 25 to 60 ° C. When the mixing temperature is less than 10 ° C., the viscosity of the dispersed phase is too high, and it may not be uniformly dispersed, and many coarse particles exceeding 1000 μm may be generated. In this case, the droplets are coalesced, and a particle having a small particle size cannot be obtained.

  The compounding amount of the curing agent is preferably 1 to 100% by mass, more preferably 1 to 60% by mass, and further preferably 1 to 30% by mass with respect to 100% by mass of the epoxy resin. The curing agent may be added as it is, or may be dissolved or dispersed in the epoxy resin in advance before emulsification, but it is preferable to add it in a solution state for uniform curing. Any solvent can be used as long as it can dissolve the curing agent, and water that is the same as the dispersion medium of the epoxy resin is particularly preferable.

  The heating temperature for curing the epoxy resin is preferably 20 ° C to 200 ° C, more preferably 20 ° C to 100 ° C, and even more preferably 40 ° C to 80 ° C. The time for performing the curing reaction is preferably in the range of 10 minutes to 100 hours, more preferably 30 minutes to 50 hours, and even more preferably 1 hour to 20 hours. In addition, the reaction atmosphere may be any of air, an inert gas atmosphere such as nitrogen, argon, carbon dioxide, or the like, but is preferably a nitrogen atmosphere.

  The stirring speed when the epoxy resin is cured to form fine particles is preferably 100 to 1600 rpm, more preferably 200 to 900 rpm, and still more preferably 300 to 600 rpm.

  By operating at these temperature, time, and stirring conditions, the dispersion (A1) containing the desired cured epoxy resin fine particles (A) can be obtained without aggregation and fusion.

  In preparing the metal oxide-containing aqueous dispersion of the cured epoxy resin particles of the present invention, the order of mixing the dispersion (A1) and the metal oxide (B) or the metal oxide dispersion (B1) is as follows. There is no particular limitation. The organic binder resin and various additives are mixed so that the cured epoxy resin fine particles (A) and the metal oxide (B) are in a good dispersion state.

  In the mixing, it is preferable to use a disperser. A known disperser can be used as the disperser. The dispersing device is not particularly limited, and examples thereof include a ball mill, a bead mill, a blender mill, an ultrasonic mill, a paint shaker, a homogenizer, a disper, a stirring blade mixer, a three roll, a Henschel mixer, and a rotation / revolution mixer. Moreover, you may perform a heating, cooling, pressurization, or pressure reduction at the time of mixing.

  The metal oxide dispersion (B1) is not particularly limited, and the metal oxide (B) dispersed in water or a solvent miscible with water can be used.

  Thus, the resin fine particle dispersion produced by the method of the present invention has excellent storage stability and can contain metal oxides in a wide range of concentrations, and the epoxy resin cured fine particles contained therein have high hardness and heat resistance. It is extremely useful for various applications in a wide range of fields such as paint, printing, adhesion, cosmetics, and medicine.

  Specifically, it can be expected as a cosmetic property modifier, a toner additive, a rheology modifier such as a paint, a medical diagnostic test agent, a resin molded article, a film, a fiber, and other mechanical property improvers. It is also extremely useful as a raw material for fine ceramic thin films used in antireflection films, cut filters for infrared sensors, cut filters for X-ray sensors, bandpass filters for medical analyzers, and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these.

  In the following examples, the amount of unreacted epoxy resin, average particle size, particle size distribution index, and glass transition temperature in the particles are values measured by the following methods.

(1) Method for measuring the amount of unreacted epoxy resin in the particles After the dispersion (A1) containing the cured epoxy resin fine particles (A) is centrifuged at 15000 G, the supernatant liquid is removed, and the supernatant liquid removed there The same amount of ion-exchanged water was added to redisperse the particles (A), and then the mixture was centrifuged again at 15000 G and the supernatant was removed. The paste-like material thus obtained was transferred to an eggplant flask and allowed to stand in a freezer at −18 ° C. for 12 hours, and then freeze-dried for 12 hours to recover particles (A).

2 g of the particles (A) and 50 g of acetonitrile were precisely weighed in an eggplant flask, heated and stirred at 50 ° C. for 8 hours, and then suction filtered using a membrane filter. Using this filtrate, high-performance liquid chromatography (HPLC) analysis is performed under the following analysis conditions, and the amount of unreacted epoxy resin in the filtrate is quantified by an absolute calibration curve method. Converted to the amount of epoxy resin (mass%).
Analysis condition column: Inertsil ODS-3 4.6 mmI. D. × 25cm
Column temperature: 40 ° C
Mobile phase: acetonitrile / water = 0.6 / 0.4
Flow rate: 1.0 ml / min
Detection: UV254 nm.

(2) Measuring method of average particle size and particle size distribution index The particles (A) after lyophilization in (1) above are attached on a conductive tape and subjected to platinum vapor deposition as a sample, and a scanning electron microscope ( JEM-6301NF, a scanning electron microscope manufactured by JEOL Ltd., was observed at a magnification of 20,000 and measured. About metal oxide (B), after affixing on the electrically conductive tape, it observed by 100,000 times by no vapor deposition.
When the particles were not perfect circles, the major axis was measured as the particle diameter. The average particle diameter was calculated by measuring an arbitrary 100 particle diameter from a photograph and calculating the arithmetic average thereof.

  The particle size distribution index indicating the particle size distribution was calculated based on the following numerical conversion formula for the individual particle diameter values obtained above.

  Here, Di: particle diameter of individual particles, n: number of measurements (100), Dn: number average particle diameter, Dv: volume average particle diameter, PDI: particle diameter distribution index.

(3) Determination of glass transition temperature by differential scanning calorimetry Using a differential scanning calorimeter (Robot DSC manufactured by Seiko Instruments Inc.), from 0 ° C. in a nitrogen atmosphere to 30 ° C. higher than the expected glass transition temperature of the polymer. The temperature range up to a temperature exceeding the temperature was raised once at a rate of temperature rise of 20 ° C./minute, held for 1 minute, then lowered to 0 ° C. at 20 ° C./minute, held for 1 minute, and then again 20 ° C./minute. In the DSC curve obtained when the temperature is raised in minutes, the straight line equidistant in the vertical axis direction from the extended straight line of the low temperature side and high temperature side base line and the curve of the step-like change part of the glass transition The temperature was the glass transition temperature (Tg).

  The DSC curve here is a differential scan in which the vertical axis represents the difference in thermal energy input per unit time applied to the test piece and the reference material so that the temperatures are equal, and the horizontal axis represents the temperature. It refers to the curve drawn in calorimetry.

(4) Storage stability evaluation of aqueous dispersion 30 g of aqueous dispersion was placed in a screw tube bottle with a height of 6.5 cm and a diameter of 3 cm and left in a thermostatic bath at 60 ° C. for 2 weeks. Visually evaluated according to the criteria. If the precipitate was easily redispersed by shaking the container, it was marked as ◯, and if the precipitate was not redispersed even when the container was shaken, it was marked as x.

Reference Example 1 <Production of Epoxy Resin Cured Product Fine Particle Dispersion (A1) [1]>
In a separable flask, 100 parts by mass of bisphenol A diglycidyl ether (“jER” (registered trademark) 828, manufactured by Mitsubishi Chemical Corporation) and polyoxyethylene styrenated phenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “ 10 parts by weight of Neugen "(registered trademark) EA-177) was added, heated to 40 ° C., and stirred at 333 rpm for 20 minutes using one four inclined paddle blades. While stirring at 333 rpm, 120 parts by mass of ion-exchanged water as a dispersion medium is dropped at a speed of 1.5 parts by mass / min via a liquid feed pump, and the water droplets in oil in which the aqueous phase is dispersed. After forming a type emulsion (hereinafter referred to as a W / O type emulsion), an oil-in-water emulsion (hereinafter referred to as an O / W type emulsion) in which an oil phase was dispersed in an aqueous phase was prepared. Thereafter, a curing agent aqueous solution in which 30 parts by mass of piperazine hexahydrate (manufactured by Tokyo Chemical Industry Co., Ltd., special grade) as a curing agent is dissolved in 180 parts by mass of ion-exchanged water is added via a liquid feed pump to 4 parts by mass. After dropwise addition at a speed of parts / min, a curing reaction was performed at 40 ° C. and a stirring speed of 333 rpm for 24 hours to obtain [fine particle dispersion 1] as a dispersion (A1) of cured epoxy resin particles. The obtained fine particles had an average particle size of 490 nm, PDI of 1.3, the amount of unreacted epoxy resin in the particles was 3% by mass, and Tg = 90 ° C.

Reference Example 2 <Production of Epoxy Resin Cured Product Fine Particle Dispersion (A1) [2]>
In a separable flask, 100 parts by mass of bisphenol A diglycidyl ether (“jER” (registered trademark) 828, manufactured by Mitsubishi Chemical Corporation) and polyoxyethylene styrenated phenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “ 10 parts by weight of Neugen "(registered trademark) EA-177) was added, heated to 40 ° C., and stirred at 333 rpm for 20 minutes using one four inclined paddle blades. While stirring at 333 rpm, 120 parts by mass of ion-exchanged water as a dispersion medium was dropped at a speed of 1.5 parts by mass / minute via a liquid feed pump, and after formation of a W / O type emulsion, An O / W type emulsion was prepared. Thereafter, a curing agent aqueous solution in which 8 parts by mass of piperazine hexahydrate (manufactured by Tokyo Chemical Industry Co., Ltd., special grade) as a curing agent is dissolved in 180 parts by mass of ion-exchanged water is added via a liquid feed pump to 4 masses. After dropwise addition at a speed of parts / minute, a curing reaction was performed at 40 ° C. and a stirring speed of 333 rpm for 24 hours to obtain [fine particle dispersion 2] as a dispersion (A1) of cured epoxy resin particles. The obtained fine particles had an average particle size of 502 nm, PDI of 1.3, the amount of unreacted epoxy resin in the particles was 15% by mass, and Tg = 72 ° C.

Examples 1 and 2 <Production of metal oxide-containing aqueous dispersion of cured epoxy resin particles [1]>
The above [fine particle dispersion 1] and [fine particle dispersion 2] were diluted with ion-exchanged water, and the epoxy cured product fine particle concentration in the dispersion was adjusted to 20% by mass. To 100 parts by mass of the prepared dispersion, 2 parts by mass of fine particle titanium oxide having an average particle size of 30 nm (manufactured by Teika Co., Ltd., MT-500HD) is added and subjected to bead milling for 12 hours, and the metal oxide of the cured epoxy resin particles A containing aqueous dispersion was obtained.

Examples 3 and 4 <Production of metal oxide-containing aqueous dispersion of fine particles of cured epoxy resin [2]>
The above [fine particle dispersion 1] and [fine particle dispersion 2] were diluted with ion-exchanged water, and the concentration of fine particles of epoxy cured product in the dispersion was adjusted to 10% by mass. To 100 parts by weight of the prepared dispersion, 10 parts by weight of fine particle titanium oxide having an average particle size of 30 nm (manufactured by Teika Co., Ltd., MT-500HD) is added and subjected to bead mill treatment for 12 hours, and the metal oxide of the cured epoxy resin particles A containing aqueous dispersion was obtained.

Examples 5 and 6 <Production of metal oxide-containing aqueous dispersion of fine particles of cured epoxy resin [3]>
The above [fine particle dispersion 1] and [fine particle dispersion 2] were diluted with ion-exchanged water, and the epoxy cured product fine particle concentration in the dispersion was adjusted to 1% by mass. To 100 parts by mass of the prepared dispersion, 20 parts by mass of fine particle titanium oxide having an average particle size of 30 nm (manufactured by Teika Co., Ltd., MT-500HD) is added and subjected to bead milling for 12 hours, and the metal oxide of the cured epoxy resin particles A containing aqueous dispersion was obtained.

Reference Example 3 <Production of dispersion of finely divided epoxy resin cured product [1]>
In a separable flask, 100 parts by mass of bisphenol A diglycidyl ether (“jER” (registered trademark) 828, manufactured by Mitsubishi Chemical Corporation) and polyoxyethylene styrenated phenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “ 10 parts by weight of Neugen "(registered trademark) EA-177) was added, heated to 40 ° C., and stirred at 333 rpm for 20 minutes using one four inclined paddle blades. While stirring at 333 rpm, 120 parts by mass of ion-exchanged water as a dispersion medium was dropped at a speed of 1.5 parts by mass / minute via a liquid feed pump, and after formation of a W / O type emulsion, An O / W type emulsion was prepared. Thereafter, a curing agent aqueous solution in which 5 parts by mass of piperazine hexahydrate (manufactured by Tokyo Chemical Industry Co., Ltd., special grade) as a curing agent is dissolved in 180 parts by mass of ion-exchanged water is passed through a liquid feed pump to 4 masses. After dropwise addition at a speed of parts / min, a curing reaction is performed at 40 ° C. and a stirring speed of 333 rpm for 24 hours, thereby obtaining [fine particle dispersion 3] as a dispersion of finely cured epoxy resin cured particles. It was. The average particle diameter of the obtained fine particles was 487 nm, PDI was 1.3, the amount of unreacted epoxy resin in the particles was 45% by mass, and Tg = 40 ° C.

Reference Example 4 <Production of Cured Epoxy Resin Cured Fine Particle Dispersion [2]>
In a separable flask, 100 parts by mass of bisphenol A diglycidyl ether (“jER” (registered trademark) 828, manufactured by Mitsubishi Chemical Corporation) and polyoxyethylene styrenated phenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “ 10 parts by weight of Neugen "(registered trademark) EA-177) was added, heated to 40 ° C., and stirred at 333 rpm for 20 minutes using one four inclined paddle blades. While stirring at 333 rpm, 120 parts by mass of ion-exchanged water as a dispersion medium was dropped at a speed of 1.5 parts by mass / minute via a liquid feed pump, and after formation of a W / O type emulsion, An O / W type emulsion was prepared. Thereafter, a curing agent aqueous solution in which 4 parts by mass of piperazine hexahydrate (manufactured by Tokyo Chemical Industry Co., Ltd., special grade) as a curing agent is dissolved in 180 parts by mass of ion-exchanged water is passed through a liquid feed pump to 4 masses. After dropwise addition at a speed of parts / min, a curing reaction is performed at 40 ° C. and a stirring speed of 333 rpm for 24 hours, thereby obtaining [fine particle dispersion 4] as a dispersion of finely cured epoxy resin hard particles. It was. The obtained fine particles had an average particle size of 483 nm, PDI of 1.3, the amount of unreacted epoxy resin in the particles was 52% by mass, and Tg = 30 ° C.

Comparative Examples 1 and 2 <Production of Metal Oxide-Containing Aqueous Dispersion of Cured Epoxy Resin Cured Fine Particles>
The above [fine particle dispersion 3] and [fine particle dispersion 4] were diluted with ion-exchanged water, and the concentration of fine particles of epoxy cured product in the dispersion was adjusted to 10% by mass. To 100 parts by weight of the prepared dispersion, 10 parts by weight of fine particle titanium oxide having an average particle size of 30 nm (manufactured by Teika Co., Ltd., MT-500HD) is added and subjected to bead mill treatment for 12 hours, and the metal oxide of the cured epoxy resin particles A containing aqueous dispersion was obtained.

<Evaluation>
The storage stability of the aqueous dispersions obtained in Examples 1 to 6 and Comparative Examples 1 and 2 was evaluated. The results are shown in <Table 1>.

Claims (6)

An aqueous dispersion containing the cured epoxy resin particles (A) and the metal oxide (B), the amount of the unreacted epoxy resin in the cured epoxy resin particles (A) is 0 to 30% by mass, And the average particle diameter is 0.05-100 micrometers, The metal oxide containing aqueous dispersion of the epoxy resin hardened material microparticles | fine-particles characterized by the above-mentioned. When the mass of the metal oxide (B) in the aqueous dispersion is W1, and the mass of the cured epoxy resin fine particles (A) is W2, the relationship of 0.01 ≦ W1 / W2 ≦ 100 is satisfied. The metal oxide-containing aqueous dispersion of fine particles of cured epoxy resin according to claim 1. 3. The metal oxide-containing aqueous dispersion of cured epoxy resin particles according to claim 1, wherein the cured epoxy resin particles (A) have a glass transition temperature of more than 50 ° C. 3. The cured epoxy resin particles according to any one of claims 1 to 3, wherein the cured epoxy resin particles (A) are epoxy resin cured particles obtained by curing a bifunctional epoxy resin with a curing agent. Metal oxide-containing aqueous dispersion. 5. The metal oxide-containing aqueous dispersion of fine particles of cured epoxy resin according to claim 1, wherein the curing agent is an amine-based curing agent. A hardener is added to the emulsion in which the epoxy resin is dispersed in the form of droplets, the unreacted epoxy resin component is cured into particles, and a dispersion liquid (A1) containing fine particles of the cured epoxy resin (A) is obtained. The liquid (A1) and the metal oxide (B) or the metal oxide dispersion (B1) are mixed, and the metal oxide-containing water dispersion of the cured epoxy resin particles according to any one of claims 1 to 5 Liquid manufacturing method.