JP2006076822A - Ultraviolet ray-curing resin composition for ceramic fabrication, manufacturing method of ceramic molding and ceramic precursor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for ceramic photo-fabrication capable of obtaining three-dimensional moldings of more minute and complex shape, and a manufacturing method of a ceramics molding. <P>SOLUTION: This ultraviolet ray-curing resin composition for a ceramic molding comprises an inorganic minute particle bonded to a polymerizable unsaturated group. This manufacturing method of a ceramic molding contains a process (1) in which the ultraviolet ray-curing resin composition for a ceramic molding is cured in a desired shape by site selectively irradiating an ultraviolet ray to a part of a layer comprising the ultraviolet ray-curing resin composition for ceramic molding and a process (2) in which the inorganic minute particle in the cured product obtained is sintered to a ceramic molding. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photocurable resin composition useful for ceramics modeling. More specifically, the present invention relates to an ultraviolet curable resin composition for ceramic molding, a method for producing a ceramic molded body, and a ceramic molded body precursor that can form a ceramic molded body having a complicated shape that cannot be realized by a conventional ceramic molding method.

  Since a conventional ceramic molded body is produced by a cutting method or an injection molding method, the degree of freedom of its shape is remarkably limited. As a technique for obtaining a free shape, a molded body to be a master is formed by stereolithography or other methods, and after the molded product is embedded with a material that is changed from a liquid state to a solid state by cooling or heating, the master is removed to form a transfer mold. There is a method of molding and injecting a fluid ceramic material into a transfer mold and then firing the whole to obtain a ceramic molded body (see, for example, Patent Document 1). However, this method increases the degree of freedom of shape as compared with the cutting method and the injection molding method, but the shape degree of freedom is still limited because the master needs to be removed.

  A ceramic molded body having excellent degree of freedom in shape can be obtained by mixing ceramic particles with a resin for optical modeling and firing an optical modeling object by a sequential lamination method (see, for example, Patent Document 2). However, the sequential lamination method has a limitation on the viscosity of the ultraviolet curable resin composition, and it is difficult to use a high viscosity ultraviolet curable resin composition. In addition, the raw material particles for forming ceramics are usually those having a particle size of several microns to several tens of microns, but the ultraviolet curable resin composition using this as a raw material is poor in transparency, and light scattering is severe when irradiated with ultraviolet rays. It is extremely difficult to perform fine modeling.

  However, by making ceramic particles ultrafine particles of 100 nm or less, light scattering can be suppressed and fine modeling can be performed. However, the ultraviolet curable resin composition containing the ceramic particles is extremely high in thixotropy and flows. Therefore, the conventional stereolithography technique (see, for example, Non-Patent Document 1) cannot be layered. It is possible to obtain apparent fluidity by dispersing in a volatile solvent. After coating and drying a solvent-dispersed resin, two-dimensional partial selective UV irradiation is performed to cure the resin composition. However, when performing sequential layered manufacturing, the solvent of the next layer dissolves the uncured resin of the previous layer, and the coating film thickness cannot be controlled, so that a solvent-dispersed resin cannot be used.

JP-A-6-329460 JP-A-8-91940 Paul F. Jacobs, “Basics of High-Speed Three-Dimensional Molding”, 1st edition, Nikkei BP Publishing Center, December 10, 1993, p. 379-406

  An object of the present invention is to provide a resin composition for optical modeling of ceramics and a method for producing a ceramic molded body, which can solve the problems of the above-described technology and obtain a three-dimensional modeled object having a finer and more complicated shape. And

  In order to achieve the above-mentioned object, the present inventors have conducted intensive research, and by bonding a polymerizable unsaturated group to the ceramic particles, the particles can be imparted with ultraviolet polymerizability. Ultraviolet rays are condensed into the resin composition layer by using an optical method (short focus lens or intersection of plural ultraviolet laser beams), and the light condensing position (hereinafter also referred to as “light collecting portion”) is used. It was found that a fine three-dimensional shape can be obtained by moving three-dimensionally and curing an arbitrary position. Further, it has been found that if extremely fine ceramic particles having a particle size of 70 nm or less are used, the transmittance of ultraviolet rays is high and light scattering can be suppressed, so that finer and more complicated modeling is possible.

  Furthermore, it is possible to obtain a finely shaped ceramic molded body by firing a three-dimensional structure obtained by curing the ultraviolet curable resin composition. Conventionally, however, distortion occurs due to volume shrinkage during firing. The obtained molded body was sometimes damaged, but it was found that such a problem can be effectively prevented by introducing a polymerizable unsaturated group into the ceramic particles.

In addition, as a means to more effectively prevent damage to the molded body due to distortion during firing, when firing the three-dimensional structure, the organic matter is decomposed but once fired at a temperature at which the ceramic does not sinter. It was found that a ceramic precursor composed only of inorganic fine particles was obtained, and this ceramic precursor was impregnated with a fluid ceramic material that forms ceramic by firing, and then fired at a temperature at which the ceramic is sintered. .
The present invention has been completed based on the above findings.

That is, the present invention
[1] (1) Ultraviolet rays are condensed at a specific position of a layer made of an ultraviolet curable resin composition containing inorganic fine particles using an optical method, and the condensing part is three-dimensionally arranged on the layer. A step of selectively irradiating ultraviolet rays by moving to an arbitrary position in the resin to cure the ultraviolet curable resin composition into a desired shape, and (2) inorganic fine particles in the obtained cured product. A method for producing a ceramic molded body comprising a step of sintering to form a ceramic molded body;
[2] The method for producing a ceramic molded body according to the above [1], wherein the inorganic fine particles have a polymerizable unsaturated group;
[3] The step of (2) sintering the inorganic fine particles in the obtained cured product to form a ceramic molded body, (2-1) the organic components in the cured product are thermally decomposed, but the inorganic fine particles Heating the cured product at a temperature at which it does not sinter and decomposing the organic component to obtain a ceramic precursor consisting essentially of inorganic fine particles; (2-2) the ceramic precursor comprising inorganic fine particles A method for producing a ceramic molded body according to the above [1] or [2], comprising a step of heating at a sintering temperature to form a ceramic molded body;
[4] The step of (2) sintering the inorganic fine particles in the obtained cured product to form a ceramic molded body, (2-1) the organic component in the cured product is thermally decomposed, but the inorganic fine particles Heating the cured product at a temperature that does not sinter and decomposing the organic components to obtain a ceramic precursor consisting essentially of inorganic fine particles; and (2-3) firing the ceramic into the ceramic precursor by firing. A step of impregnating a fluid ceramic material to be formed to obtain a fluid ceramic material-impregnated ceramic precursor; and (2-4) sintering the fluid ceramic material-impregnated ceramic precursor with inorganic fine particles and fluid ceramic material. A method for producing a ceramic molded body according to the above [1] or [2], comprising a step of heating at a temperature to form a ceramic molded body;
[5] A ceramic precursor having a desired shape substantially composed only of inorganic fine particles having an average particle diameter of 5 to 70 nm;
[6] A fluid ceramic material-impregnated ceramic precursor, wherein the ceramic precursor according to [5] is impregnated with a fluid ceramic material that forms ceramics by firing; and [7] an average particle diameter of 5 to 5; Provided is a ceramic molded body having a desired shape substantially composed only of 70 nm inorganic fine particles.

  According to the present invention, it is possible to obtain a ceramic molded body having a fine and complicated shape that cannot be realized by a conventional ceramic molding method.

  ADVANTAGE OF THE INVENTION According to this invention, the failure | damage of the molded object resulting from the distortion produced by the volume shrinkage which arises at the time of the conventional ceramic baking can be prevented effectively.

Hereinafter, the present invention will be described in detail.
I. Ultraviolet curable resin composition for ceramic modeling The ultraviolet curable resin composition for ceramic modeling used in the present invention (hereinafter referred to as the composition of the present invention) contains inorganic fine particles to which polymerizable unsaturated groups are bonded. It is characterized by that.

In addition to the inorganic fine particles to which (A) a polymerizable unsaturated group is bonded, the composition of the present invention includes, as an optional component:
(B) a photoradical reaction initiator,
(C) a polymerizable binder,
(D) an organic solvent,
(E) a dispersant, and (F) other additives can be included.

I-1. Hereinafter, each component will be described.
(A) Inorganic fine particles to which polymerizable unsaturated groups are bonded Inorganic fine particles to which polymerizable unsaturated groups are bonded are particles in which inorganic fine particles are chemically modified to bond polymerizable unsaturated groups (hereinafter, “ By using this, the particles are chemically bonded to each other by irradiation with curing light (ultraviolet rays), so that cracking during sintering can be prevented. .

(1) (A) Component constituting modified particle (A-1) Inorganic fine particle As long as the inorganic fine particle used in the present invention is an inorganic fine particle that does not substantially absorb or scatter light having an irradiation wavelength. There is no particular limitation.

  Examples of the inorganic fine particles include fine particles mainly containing inorganic oxides, inorganic carbides, inorganic nitrides, and the like, and these can be used alone or in combination of two or more.

  Examples of the inorganic oxide include silica, aluminum oxide, zirconia, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, and cerium oxide.

  Examples of inorganic carbides include zirconium carbide and silicon carbide.

  Examples of the inorganic nitride include aluminum nitride and silicon nitride.

  As the inorganic fine particles, aluminum oxide, silica, silicon carbide, zirconia, yttria, or a mixture thereof is preferably used.

  The inorganic fine particles are preferably powdery or solvent-dispersed sol. In the case of a solvent dispersion sol, the dispersion medium is preferably an organic solvent from the viewpoint of compatibility with other components and dispersibility. Examples of such an organic solvent include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, ethyl lactate, and γ-butyrolactone. Esters such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether; aromatic hydrocarbons such as benzene, toluene and xylene; amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone it can. Of these, methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene and xylene are preferred.

  The particle size of the inorganic fine particles is usually in the range of 5 to 100 nm, preferably in the range of 5 to 70 nm, more preferably in the range of 10 to 50 nm. If the particle size of the inorganic fine particles is less than 5 nm, the production of the inorganic fine particles is difficult, and the volume shrinkage at the time of firing is large, so that the particles are easily broken. When the particle size exceeds 100 nm, scattering of curing light (ultraviolet rays) increases and the accuracy of modeling is impaired.

Examples of products that are commercially available as silica fine particles that are inorganic oxides include, for example, colloidal silica, product names manufactured by Nissan Chemical Industries, Ltd .: methanol silica sol, IPA-ST, MEK-ST, NBA-ST, and XBA. -ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL, etc. can be mentioned. As the powder silica, trade names manufactured by Nippon Aerosil Co., Ltd .: Aerosil 130, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil OX50, manufactured by Asahi Glass Co., Ltd. Trade names: Sildex H31, H32, H51, H52, H121 H122, Nippon Silica Kogyo Co., Ltd. trade names: E220A, E220, Fuji Silysia Co., Ltd. trade names: SYLYSIA 470, Nippon Sheet Glass Co., Ltd. trade names: SG Flakes, and the like.

  Moreover, as a product marketed as an aluminum oxide (alumina), Nissan Chemical Industries Ltd. brand name: Alumina sol-100, -200, -520 can be mentioned as an aqueous dispersion.

  As an aqueous dispersion product of zinc antimonate powder, trade name: Celnax manufactured by Nissan Chemical Industries, Ltd. can be mentioned.

  Examples of powders and solvent-dispersed products such as alumina, titanium oxide, tin oxide, indium oxide, and zinc oxide include trade name: NANOTECH manufactured by CI Kasei Co., Ltd.

  Examples of the water-dispersed sol of antimony-doped tin oxide include products manufactured by Ishihara Sangyo Co., Ltd., trade name: SN-100D, and ITO powders manufactured by Mitsubishi Materials Corporation.

  Examples of the cerium oxide aqueous dispersion include trade name: Niedal manufactured by Taki Chemical Co., Ltd.

  The shape of the inorganic fine particles is not particularly limited, but is, for example, spherical, hollow, porous, rod-like, plate-like, fibrous, or indefinite, and preferably spherical.

The specific surface area of the inorganic fine particles (by BET method using nitrogen) is preferably 10 to 1000 m ² / g, more preferably 100 to 500 m ² / g.

  The inorganic fine particles can be used in a dry state, or dispersed in water or an organic solvent. For example, a finely divided inorganic fine particle dispersion known in the art as the solvent dispersion sol of the inorganic fine particles can be used directly. In particular, the use of a solvent-dispersed sol of an inorganic oxide is preferable in applications that require excellent transparency in a cured product.

(A-2) Polymerizable unsaturated group The polymerizable unsaturated group bonded to the inorganic fine particles is:
(A) a polymerizable unsaturated group,
(B) The following formula (1)

(In formula (1), X represents NH, O (oxygen atom) or S (sulfur atom), Y represents O or S), and (c) a silanol group or water It is a group derived from a compound containing a group that generates a silanol group by decomposition (hereinafter sometimes referred to as a polymerizable unsaturated group-containing compound), and the inorganic fine particles and the compound are bonded via a silyloxy group.

(A) Polymerizable unsaturated group The polymerizable unsaturated group is not particularly limited. For example, acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, cinnamoyl group, malee- Group and acrylamide group can be mentioned as preferred examples, and a (meth) acryloyl group is preferred. This (a) polymerizable unsaturated group is a structural unit that undergoes addition polymerization with active radical species.

(B) Group represented by Formula (1) The group [—X—C (═Y) —NH—] represented by Formula (1) is specifically [—O—C (═O)]. —NH—], [—O—C (═S) —NH—], [—S—C (═O) —NH—], [—NH—C (═O) —NH—], [—NH. -C (= S) -NH-] and [-S-C (= S) -NH-]. These groups can be used individually by 1 type or in combination of 2 or more types. Among them, from the viewpoint of thermal stability, [—O—C (═O) —NH—] group, [—O—C (═S) —NH—] group and [—S—C (═O) — It is preferable to use in combination with at least one of the NH— groups. The group [—X—C (═Y) —NH—] represented by the formula (1) generates an appropriate cohesive force due to hydrogen bonding between molecules, and gives excellent mechanical strength when formed into a cured product. It is considered to be a cause.

(C) Silanol or a group that generates a silanol group by hydrolysis Silanol or a group that generates a silanol group by hydrolysis includes a compound containing a silanol group in the molecule (hereinafter sometimes referred to as “silanol group-containing compound”) or It is a group derived from a compound that generates a silanol group by hydrolysis (hereinafter sometimes referred to as “silanol group-generating compound”). Examples of the silanol group-forming compound include compounds having an alkoxy group, aryloxy group, acetoxy group, amino group, halogen atom, etc. on the silicon atom, but compounds having an alkoxy group or aryloxy group on the silicon atom That is, an alkoxysilyl group-containing compound or an aryloxysilyl group-containing compound is preferable. The silanol group-generating site of the silanol group or the silanol group-generating compound is a structural unit that binds to the inorganic fine particles by a condensation reaction or a condensation reaction that occurs following hydrolysis.

Preferable specific examples of the polymerizable unsaturated group-containing compound include, for example, a compound represented by the following formula (2).

In formula (2), R ¹ and R ² may be the same or different, but are a hydrogen atom or a C _{1 to} C ₈ alkyl group or aryl group, such as methyl, ethyl, propyl, butyl, octyl, Examples thereof include phenyl and xylyl groups. Here, m is 1, 2 or 3.

Examples of the group represented by [(R ¹ O) _m R ² _3-m Si—] include a trimethoxysilyl group, a triethoxysilyl group, a triphenoxysilyl group, a methyldimethoxysilyl group, and a dimethylmethoxysilyl group. Can be mentioned. Of these groups, a trimethoxysilyl group or a triethoxysilyl group is preferable.

R ³ is a divalent organic group having a C _{1 to} C ₁₂ aliphatic or aromatic structure, and may contain a chain, branched or cyclic structure. Examples of such an organic group include methylene, ethylene, propylene, butylene, hexamethylene, cyclohexylene, phenylene, xylylene, and dodecamethylene. Among these, preferred examples are methylene, propylene, cyclohexylene, phenylene and the like.

R ⁴ is a divalent organic group, and is usually selected from divalent organic groups having a molecular weight of 14 to 10,000, preferably a molecular weight of 76 to 500. For example, chain polyalkylene groups such as hexamethylene, octamethylene, dodecamethylene; alicyclic or polycyclic divalent organic groups such as cyclohexylene and norbornylene; divalent groups such as phenylene, naphthylene, biphenylene and polyphenylene Aromatic group; and these alkyl group-substituted and aryl group-substituted products. Further, these divalent organic groups may contain an atomic group containing an element other than carbon and hydrogen atoms, and include a polyether bond, a polyester bond, a polyamide bond, a polycarbonate bond, and a group represented by the formula (1). Can also be included.

R ⁵ is an (n + 1) -valent organic group, preferably selected from a chain, branched or cyclic saturated hydrocarbon group and unsaturated hydrocarbon group.

  Z represents a monovalent organic group having a polymerizable unsaturated group in the molecule that undergoes an intermolecular crosslinking reaction in the presence of an active radical species. For example, acryloyl (oxy) group, methacryloyl (oxy) group, vinyl (oxy) group, propenyl (oxy) group, butadienyl (oxy) group, styryl (oxy) group, ethynyl (oxy) group, cinnamoyl (oxy) group , Maleate group, acrylamide group, methacrylamide group and the like. Among these, an acryloyl (oxy) group and a methacryloyl (oxy) group are preferable. N is preferably a positive integer of 1 to 20, more preferably 1 to 10, particularly preferably 1 to 5.

  For the synthesis of the polymerizable unsaturated group-containing compound used in the present invention, for example, a method described in JP-A-9-100111 can be used. That is, (i) it can be carried out by addition reaction of a mercaptoalkoxysilane, a polyisocyanate compound, and an active hydrogen group-containing polymerizable unsaturated compound. (B) The reaction can be carried out by a direct reaction between a compound having an alkoxysilyl group and an isocyanate group in the molecule and an active hydrogen-containing polymerizable unsaturated compound. Furthermore, (c) it can also be directly synthesized by an addition reaction of a compound having a polymerizable unsaturated group and an isocyanate group in the molecule with mercaptoalkoxysilane or aminosilane.

  In order to synthesize the compound represented by the formula (2), among these methods, (i) is preferably used. More specifically, for example, the (a-a) method; first, by reacting a mercaptoalkoxysilane and a polyisocyanate compound, an alkoxysilyl group, [—S—C (═O) NH—] group and An intermediate containing an isocyanate group is formed, and then the isocyanate remaining in the intermediate is reacted with a hydroxy group-containing polymerizable unsaturated compound to convert the unsaturated compound to [—O—C (═O) — A method of bonding via an NH-] group, (b) method; first, a polyisocyanate compound and a hydroxy group-containing polymerizable unsaturated compound are reacted to form a polymerizable unsaturated group in the molecule, [—O— An intermediate containing a C (═O) —NH—] group and an isocyanate group is formed, and this is reacted with mercaptoalkoxysilane to convert this mercaptoalkoxysilane to [—S—C (═O). Method of binding via NH-] groups, and the like. Further, among them, the method (ii) is preferable in that there is no decrease in polymerizable unsaturated groups due to the Michael addition reaction.

  In the synthesis of the compound represented by the formula (2), as an example of an alkoxysilane capable of forming a [—S—C (═O) —NH—] group by reaction with an isocyanate group, an alkoxysilyl group And compounds having at least one mercapto group in the molecule. Examples of such mercaptoalkoxysilane include mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptopropylmethyldiethoxysilane, mercaptopropyldimethoxymethylsilane, mercaptopropylmethoxydimethylsilane, mercaptopropyltriphenoxy silane, mercapto Mention may be made of propyltributoxysilane. Among these, mercaptopropyltrimethoxysilane and mercaptopropyltriethoxysilane are preferable. Moreover, an addition product of an amino-substituted alkoxysilane and an epoxy group-substituted mercaptan and an addition product of an epoxysilane and an α, ω-dimercapto compound can also be used.

  The polyisocyanate compound used for synthesizing the polymerizable unsaturated group-containing compound can be selected from polyisocyanate compounds composed of chain saturated hydrocarbons, cyclic saturated hydrocarbons, and aromatic hydrocarbons. .

  Examples of such polyisocyanate compounds include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4. -Xylylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4, 4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, methylene bis (4- (Cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, bis (2-isocyanate) Ethyl) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,3-bis (Isocyanatemethyl) cyclohexane, tetramethylxylylene diisocyanate, 2,5 (or 6) -bis (isocyanatemethyl) -bicyclo [2.2.1] heptane, and the like. Among these, 2,4-tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, methylenebis (4-cyclohexylisocyanate), 1,3-bis (isocyanatemethyl) cyclohexane, and the like are preferable. These can be used alone or in combination of two or more.

  In the synthesis of a polymerizable unsaturated group-containing compound, examples of the active hydrogen-containing polymerizable unsaturated compound that can be bonded to the polyisocyanate compound via an [—O—C (═O) —NH—] group by an addition reaction , Having at least one active hydrogen atom capable of forming a [—O—C (═O) —NH—] group by addition reaction with an isocyanate group in the molecule and containing at least one polymerizable unsaturated group A compound can be mentioned.

  Examples of these active hydrogen-containing polymerizable unsaturated compounds include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2- Hydroxy-3-phenyloxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate 1,6-hexanediol mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethanedi (meth) acrylate, pentaerythr Litholtri (meth) acrylate, dipentaerythritol penta Data) acrylate - door, and the like can be given. Moreover, the compound obtained by addition reaction with glycidyl group containing compounds, such as alkyl glycidyl ether, allyl glycidyl ether, and glycidyl (meth) acrylate, and (meth) acrylic acid can be used. Among these compounds, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate and the like are preferable. These compounds can be used individually by 1 type or in mixture of 2 or more types.

(A-3) Compound containing no polymerizable unsaturated group and containing a silanol group or a group that generates a silanol group by hydrolysis In the present invention, (A-2) polymerizable unsaturated group-containing compound ((a In addition to (a) a polymerizable unsaturated group, (b) a group represented by the formula (1), and (c) a silanol group or a compound that generates a silanol group by hydrolysis), if necessary, (A-3) a compound that does not contain a polymerizable unsaturated group and contains a silanol group or a group that generates a silanol group by hydrolysis (hereinafter referred to as “(A-3) a polymerizable unsaturated group-free compound”). May be used to further modify the inorganic fine particles. This (A-3) polymerizable unsaturated group-free compound is different from the polymerizable unsaturated group-containing compound in that it does not contain a polymerizable unsaturated group in the molecule. The meaning of the silanol group in the (A-3) polymerizable unsaturated group-free compound or the group that generates a silanol group by hydrolysis is as follows in the case of the (A-2) polymerizable unsaturated group-containing compound: It is the same.

Examples of the (A-3) polymerizable unsaturated group-free compound include a silanol group-containing compound or a hydrolyzable silane represented by the following formula (3).
(R ⁶ ) _a (R ⁷ ) _b (R ⁸ ) _c Si (R ⁹ ) _d (3)
[In the formula (3), a, b, c and d are integers of 0 to 4, a + b + c + d = 4; R ⁶ , R ⁷ and R ⁸ are monovalent organic groups, and R ⁹ is a monovalent organic group. It is. ]
Here, R ⁶ , R ⁷ and R ⁸ , which may be the same or different, are selected from C _{1 to} C ₂₀ monovalent organic groups, such as an alkyl group, an aryl group, and an aralkyl group. It is. Alkyl groups are preferred among these, further preferably an alkyl group of C ₁ -C _8.

Examples of R ⁶ , R ⁷ and R ⁸ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, sec-butyl, n-hexyl, cyclohexyl, n-octyl, and 2-ethylhexyl. And alkyl groups such as n-decyl, n-hexadecanyl and n-octadecanyl groups, aryl groups such as phenyl, xylyl, biphenyl and naphthyl groups, and aralkyl groups such as benzyl and tolyl groups.

R ⁹ represents a hydroxy group (OH group) or a group that generates a silanol group [—Si—OH] by hydrolysis (for example, a hydrogen atom, a halogen atom, an alkoxy group, an aryloxy group, an aralkyloxy group, an acyloxy group). Group, amino group, mercapto group, alkylthio group, iminooxy group).

  Of these, preferred groups are an alkoxy group, an aryloxy group, an acyloxy group, and an iminooxy group, and more preferred are an alkoxy group and an aryloxy group. Specific examples of such hydrolyzable groups include halogen atoms such as fluorine, chlorine and bromine; alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group and isobutoxy group. , T-butoxy group, sec-butoxy group, etc .; aryloxy group, phenoxy group, biphenyloxy group, etc .; aralkyloxy group, benzyloxy group, phenylethoxy group, etc .; acyloxy group, acetoxy group, benzoyloxy group, etc .; N, N-dimethylamino group, N, N-dibutylamino group, N-methyl-N-phenylamino group, etc .; mercapto group; alkylthio group, methylthio group, ethylthio group, etc .; iminooxy group, methyl Iminooxy group, ethyliminooxy group, phenyliminooxy group It can be mentioned.

  Among the compounds represented by the formula (3), hydrolyzable silanes include trimethylmethoxysilane, trimethylethoxysilane, trimethylchlorosilane, trimethylacetoxysilane, trimethyl-N, N-dimethylaminosilane, and trimethyl-N-methyliminooxysilane. , Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldichlorosilane, dimethyldiacetoxysilane, methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriacetoxysilane, tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, Tri-n-butylchlorosilane, tri-n-butylmethoxysilane, tri-n-butylethoxysilane, tri-n-butylaminosilane, tri-n-butylacetoxy Silane, phenyldimethylchlorosilane, phenyldimethylmethoxysilane, phenyldimethylethoxysilane, phenyldimethylacetoxysilane, di-n-butyldichlorosilane, di-n-butyldimethoxysilane, di-n-butyldiacetoxysilane, isopropyltrichlorosilane , Isopropyltrimethoxysilane, n-butyltrichlorosilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrichlorosilane, n-hexyltrimethoxysilane, n-octyltrichlorosilane, n-octyltrimethoxy Silane, n-decyltrichlorosilane, n-decyltrimethoxysilane, n-dodecyltrichlorosilane, n-dodecyltrimethoxysilane, n-octadecyltrichlorosilane, n-o Data decyl trimethoxysilane, phenyl trichlorosilane, phenyl trimethoxysilane, and the like phenyltriethoxysilane.

(2) (A) Compounding amount of components constituting modified particles (A-1) Inorganic fine particles, (A-2) polymerizable unsaturated group-containing compound and (A-3) polymerizable unsaturated group-free compound The blending amount of will be described.

  The blending amount of each component in the (A) modified particles used in the present invention is based on (A) modified particles (total amount of (A-1), (A-2) and (A-3)) 100% by mass. Are as follows. In addition, the quantity of (A) modified particles means solid content, and when this is used with the form of solvent dispersion | distribution sol (dispersion liquid), the quantity of a solvent is not included in the compounding quantity.

  (A-1) The inorganic fine particles are preferably blended in an amount of 30 to 99% by mass, and more preferably 50 to 98% by mass. If it is less than 30% by mass, the composition containing the modified particles is made into a cured product, and the organic component is further decomposed by heating at a temperature at which the organic component is thermally decomposed but the inorganic fine particles are not sintered. In particular, in the process of obtaining a ceramic precursor composed only of inorganic fine particles, the mechanical strength of the ceramic precursor may be low and the shape may not be maintained. When it exceeds 99% by mass, ultraviolet rays are condensed at a specific position of the layer made of the composition containing the modified particles by using an optical method, and the condensing part is arbitrarily arranged in the layer three-dimensionally. In some cases, the mechanical strength of the optically shaped article obtained by the step of selectively irradiating with ultraviolet rays by being moved to this position and curing the ultraviolet curable resin composition into a desired shape may not be sufficient.

  (A-2) The polymerizable unsaturated group-containing compound is preferably blended in an amount of 1 to 70% by mass, and more preferably 2 to 50% by mass. When it is less than 1% by mass, the curability when the composition containing the modified particles (A) is a cured product may be insufficient, and when it exceeds 70% by mass, the mechanical strength of the ceramic precursor Is low and the shape may not be maintained.

  (A-3) The polymerizable unsaturated group-free compound is preferably blended in an amount of 0.1 to 50 mass%, more preferably 0.5 to 40 mass%. If it is less than 0.1% by mass, the dispersion stability and the storage stability may be insufficient. If it exceeds 50% by mass, the mechanical strength of the ceramic precursor after decomposition of the optically shaped article and the organic component is low. It may be insufficient.

(3) (A) Modified Particle Production Method The production method of the modified particle (A) used in the present invention is not particularly limited. For example, silanol group-generating compounds ((A-2) and (A-3)) And (A-1) inorganic fine particles can be mixed, heated and stirred. In addition, the silanol group production | generation site | part which (A-2) a polymerizable unsaturated group containing compound and (A-3) a polymerizable unsaturated group non-containing compound have, and (A-1) inorganic type fine particles are combined efficiently. Therefore, the reaction is preferably performed in the presence of water. However, when the (A-2) polymerizable unsaturated group-containing compound and the (A-3) polymerizable unsaturated group-free compound have a silanol group, there is no need for water. Therefore, this (A) modified particle is an operation in which (A-1) inorganic fine particles, (A-2) a polymerizable unsaturated group-containing compound and (A-3) a polymerizable unsaturated group-free compound are mixed at least. It can manufacture by the method containing.

  Hereinafter, specific examples of a preferable method for producing the modified particles (A) used in the present invention will be described. This example has two steps, namely, a first step ((A-2) hydrolysis of a polymerizable unsaturated group-containing compound and (A-1) bonding to inorganic fine particles) and a second step. In the method of producing modified particles (A) via the step ((A-3) hydrolysis of the polymerizable unsaturated group-free compound and bonding to the particles obtained in the first step) is there. In addition, when (A-2) polymerizable unsaturated group-containing compound and (A-3) polymerizable unsaturated group-free compound are not silanol group-generating compounds but are silanol group-containing compounds, hydrolysis is not performed. May be.

Hereinafter, the two steps will be described in more detail.
<1> First Step The first step is (A-1) using a solvent dispersion sol of (A-1) inorganic fine particles or (A-1) inorganic fine particles, and (A-2) polymerization. Particles (A-1) inorganic fine particles and (A-2) polymerizable unsaturated group-containing compounds bonded together (hereinafter also referred to as “intermediate particles”). To manufacture. That is, (A-1) inorganic fine particles, (A-2) a polymerizable unsaturated group-containing compound, and water are mixed under the following conditions to produce intermediate particles. Here, for example, p-methoxyphenol may be added as a thermal polymerization inhibitor. Moreover, as a solvent, the same thing as what was used as a dispersion medium of the solvent dispersion sol of said (A-1) inorganic type microparticles | fine-particles can be used. The temperature may usually be in the range from the temperature at which no solute precipitates to the boiling point of the solvent, and preferably 0 to 150 ° C. Stirring is not particularly limited as long as it can be uniformly mixed. The atmosphere is usually in a dry gas such as nitrogen or air, and preferably in dry air. The time is usually within the range where the reaction is sufficiently completed, preferably 5 minutes to 24 hours, more preferably 1 hour to 8 hours.

<2> Second Step In the second step, the intermediate particles obtained in the first step and (A-3) a polymerizable unsaturated group-free compound are reacted as necessary to obtain intermediate particles. And (A-3) (A) modified particles in which a polymerizable unsaturated group-free compound is bonded. That is, the intermediate particles, (A-3) polymerizable unsaturated group-free compound, and water are mixed under the following conditions to produce (A) modified particles. The temperature may usually be in the range from the temperature at which no solute precipitates to the boiling point of the solvent, and preferably 0 to 150 ° C. Stirring is not particularly limited as long as it can be uniformly mixed. The atmosphere is usually in a dry gas such as nitrogen or air, and preferably in dry air. The time is usually within the range where the reaction is sufficiently completed, preferably 5 minutes to 24 hours, more preferably 1 hour to 8 hours. Thus, by passing through the first step and the second step, (A-1) inorganic fine particles, (A-2) a polymerizable unsaturated group-containing compound, and if necessary (A-3) (A) Modified particles in which a polymerizable unsaturated group-free compound is bound can be obtained.

  As described above, when (A) modified particles are produced, (A-2) after treatment with a polymerizable unsaturated group-containing compound, (A-3) treatment with a polymerizable unsaturated group-free compound is further performed. Is preferably added. (A-3) The dispersion stability of the modified particles (A) can be further improved by performing the treatment with the polymerizable unsaturated group-free compound. The treatment with the (A-2) polymerizable unsaturated group-containing compound and the (A-3) polymerizable unsaturated group-free compound simultaneously, or (A-2) prior to the treatment with the polymerizable unsaturated group-containing compound. (A-3) When the treatment with a polymerizable unsaturated group-free compound is performed, the dispersion stability of (A) modified particles may be deteriorated.

  Hereinafter, the method for producing (A) modified particles will be described in more detail. (A-1) The binding amount of the (A-2) polymerizable unsaturated group-containing compound and (A-3) polymerizable unsaturated group-free compound to the inorganic fine particles is as follows. Preferably it is 0.01 mass% or more, More preferably, it is 0.1 mass% or more, Most preferably, it is 1 mass% or more. (A-1) Bonding amounts of (A-2) polymerizable unsaturated group-containing compound and (A-3) polymerizable unsaturated group-free compound bonded to inorganic fine particles are each less than 0.01% by mass. In addition, the dispersibility of the modified particles (A) in the composition may not be sufficient, and the mechanical strength of the ceramic precursor after the stereolithography and organic component decomposition may not be sufficient. In addition, the blending ratio of (A-1) inorganic fine particles in the raw material during the production of (A) modified particles is preferably 30 to 99% by mass, more preferably 50 to 98% by mass or less, as described above. It is.

  Hereinafter, taking the alkoxysilane compound shown by said Formula (2) as an example as a silanol group production | generation compound, the manufacturing method of (A) modified particle is demonstrated still in detail. (A) The amount of water consumed by hydrolysis of the alkoxysilane compound during the production of the modified particles may be an amount such that at least one alkoxy group on silicon in one molecule is hydrolyzed. Preferably, the amount of water added or present during hydrolysis is at least one third of the number of moles of all alkoxy groups on the silicon, more preferably one half of the number of moles of all alkoxy groups. It is less than 3 times. The product obtained by mixing the alkoxysilane compound and the (A-1) inorganic fine particles under the condition that no moisture is present is the product obtained by physically adsorbing the alkoxysilane compound to the (A-1) inorganic fine particles. The effect of expressing the mechanical strength of the optically shaped article obtained from the composition containing the modified particles (A) composed of such components and the ceramic precursor after decomposition of the organic components is low.

  (A) At the time of producing modified particles, after subjecting the alkoxysilane compound to a separate hydrolysis operation, a solvent dispersion sol of this and powder (A-1) inorganic fine particles or (A-1) inorganic fine particles A method of mixing, heating and stirring; or a method of hydrolyzing the alkoxysilane compound in the presence of (A-1) inorganic fine particles; and other components such as (A-4) In the presence of a compound having two or more polymerizable unsaturated groups in the molecule, (A-5) a polymerization initiator, or the like, (A-1) a method for modifying inorganic fine particles can be selected. In this, the method of performing a hydrolysis of the said alkoxysilane compound in presence of (A-1) inorganic type microparticles | fine-particles is preferable. (A) During the production of modified particles, the temperature is preferably 0 ° C. or higher and 150 ° C. or lower, more preferably 20 ° C. or higher and 100 ° C. or lower. The processing time is usually in the range of 5 minutes to 24 hours.

  (A) When powdered oxide powder is used in the production of modified particles, an organic solvent may be added for the purpose of smoothly and uniformly carrying out the reaction with the alkoxysilane compound. As such an organic solvent, the same one as that used as the dispersion medium of the solvent dispersion sol of (A-1) inorganic fine particles can be used. The amount of these solvents added is not particularly limited as long as it meets the purpose of carrying out the reaction smoothly and uniformly.

  (A) When using a solvent-dispersed sol as a raw material for the modified particles, at least a mixture of the solvent-dispersed sol, (A-2) a polymerizable unsaturated group-containing compound and (A-3) a polymerizable unsaturated group-free compound Can be manufactured. Here, an organic solvent which is uniformly compatible with water may be added for the purpose of ensuring the uniformity at the initial stage of the reaction and allowing the reaction to proceed smoothly.

  In addition, in the production of (A) modified particles, an acid, salt or base may be added as a catalyst in order to promote the reaction. Examples of the acid include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid; organic acids such as methanesulfonic acid, toluenesulfonic acid, phthalic acid, malonic acid, formic acid, acetic acid, and succinic acid; methacrylic acid, acrylic acid, and itacone An unsaturated organic acid such as an acid, as a salt, for example, an ammonium salt such as tetramethylammonium hydrochloride or tetrabutylammonium hydrochloride, and as a base, for example, aqueous ammonia, diethylamine, triethylamine, dibutylamine, Primary, secondary or tertiary aliphatic amines such as cyclohexylamine, aromatic amines such as pyridine, quaternary ammonium hydroxides such as sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, tetrabutylammonium hydroxide Etc. Among these, preferred examples of the acid include organic acids and unsaturated organic acids, and the base includes tertiary amine or quaternary ammonium hydroxide. The addition amount of these acids, salts or bases is preferably 0.001 to 1.0 parts by weight, more preferably 0.01 to 0.1 parts by weight, with respect to 100 parts by weight of the alkoxysilane compound. In order to accelerate the reaction, it is also preferable to add a dehydrating agent. As the dehydrating agent, inorganic compounds such as zeolite, anhydrous silica, and anhydrous alumina, and organic compounds such as methyl orthoformate, ethyl orthoformate, tetraethoxymethane, and tetrabutoxymethane can be used. Of these, organic compounds are preferable, and orthoesters such as methyl orthoformate and ethyl orthoformate are more preferable. (A) The amount of the alkoxysilane compound bonded to the modified particles is usually from 110 ° C. to 800 ° C. in the air as a constant value of mass reduction% when the dry powder is completely burned in the air. This can be determined by thermogravimetric analysis.

(B) Photoradical reaction initiator The composition of the present invention radically polymerizes polymerizable unsaturated groups bonded to inorganic fine particles by ultraviolet irradiation, and initiates radical polymerization by ultraviolet irradiation. Usually, (B) a photoradical reaction initiator is contained.

  The (B) photoradical reaction initiator used in the present invention is not particularly limited as long as radical polymerization can be initiated by ultraviolet irradiation, and those generally used such as compounds that generate active radical species by ultraviolet irradiation. Can be mentioned.

  Specific examples of preferred (B) photoradical initiators include radiation polymerization initiators containing aryl ketones having 1-hydroxycyclohexyl group and / or aryl ketones having N-morpholino group. Can do. When only aryl ketones having a 1-hydroxycyclohexyl group are added, a cured product with little coloring can be formed in a short time. On the other hand, when only aryl ketones having an N-morpholino group are added, a cured product having a high surface hardness can be formed in a short time. When both are used in combination, a cured product having a high surface hardness and little coloring can be formed in a short time.

The aryl ketones having a 1-hydroxycyclohexyl group are not particularly limited, and examples thereof include 1-hydroxycyclohexyl phenyl ketone, 1-hydroxycyclohexyl isopropyl phenyl ketone, 1-hydroxycyclohexyl dodecyl phenyl ketone, and the like. The aryl ketones having an N-morpholino group are not particularly limited. For example, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1,2-methyl-1- [4- (Methoxy) phenyl] -2-morpholinopropanone-1,2-methyl-1- [4- (2-hydroxyethoxy) phenyl] -2-morpholinopropanone-1,2-methyl-1- [ 4- (Dimethylamino) phenyl] -2-morpholinopropanone-1,2-methyl-1- [4- (diphenylamino) phenyl] -2-morpholinopropanone-1,2-benzyl-2-dimethylamino- And 1- (4-morpholinophenyl) -butanone-1,3,6-bis (2-methyl-2-morpholinopropionyl) -9-N-octylcarbazole. These photo-radical reaction initiators may be used alone or in combination of two or more, but when cured, in order to improve the curing rate and hardness of both the surface portion and the interior It is preferable to use a combination of an aryl ketone having a 1-hydroxycyclohexyl group and an aryl ketone having an N-morpholino group. As a commercial item of such a photo radical reaction initiator, Ciba Specialty Chemicals Co., Ltd. brand name: Irgacure 184,907 etc. can be mentioned, for example.

(C) Polymerizable binder The (C) polymerizable binder used in the composition of the present invention as needed is a component that forms the shape of a cured product by ultraviolet irradiation, and increases the strength during optical modeling. it can.

  The polymerizable binder (C) used in the present invention is preferably a polyfunctional (meth) acrylate monomer having two or more (meth) acryl groups in the molecule.

  The (C) polymerizable binder used in the present invention is not particularly limited, and examples thereof include (meth) acrylic esters and vinyl compounds. Of these, (meth) acrylic esters are preferred. Hereinafter, specific examples of the polymerizable binder (C) used in the present invention are listed. (Meth) acrylic esters include trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) Acrylate, dipentaerythritol hexa (meth) acrylate, glycerin tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethylene glycol di (meth) acrylate, 1,3-butanediol di ( (Meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene Glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, and ethylene oxide to these starting alcohols Or propylene oxide adduct poly (meth) acrylates, oligoester (meth) acrylates having two or more (meth) acryloyl groups in the molecule, oligoether (meth) acrylates, oligourethane (meth) acrylates, And oligoepoxy (meth) acrylates. Among these, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tetra (meth) acrylate, and ditrimethylolpropane tetra (meth) acrylate are preferable. Examples of vinyl compounds include divinylbenzene, ethylene glycol divinyl ether, diethylene glycol divinyl ether, and triethylene glycol divinyl ether.

Examples of commercially available compounds that can be used as the polymerizable binder (C) include, for example, trade names manufactured by Toagosei Co., Ltd .: Aronix M-400, M-408, M-450, M-305, M -309, M-310, M-315, M-320, M-350, M-360, M-208,
M-210, M-215, M-220, M-225, M-233, M-240, M-245, M-260, M-270, M-1100, M-1200, M-1210, M- 1310, M-1600, M-221, M-203, TO-924, TO-1270, TO-1231, TO-595, TO-756, TO-1231, TO-1343, TO-902, TO-904, TO-905, TO-1330, Nippon Kayaku Co., Ltd. trade names: KAYARAD D-310, D-330, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, DN-0075, DN -2475, SR-295, SR-355, SR-399E, SR-494, SR-9041, SR-368, SR-415, SR-444, SR-4 4, SR-492, SR-499, SR-502, SR-9020, SR-9035, SR-111, SR-212, SR-213, SR-230, SR-259, SR-268, SR-272, SR-344, SR-349, SR-601, SR-602, SR-610, SR-9003, PET-30, T-1420, GPO-303, TC-120S, HDDA, NPGDA, TPGDA, PEG400DA, MANDA, HX-220, HX-620, R-551, R-712, R-167, R-526, R-551, R-712, R-604, R-684, TMPTA, THE-330, TPA-320, TPA-330, KS-HDDA, KS-TPGDA, KS-TMPTA, Kyoeisha Chemical Co., Ltd. Product name: Light Acre PE-4A, DPE-6A, can be cited DTMP-4A or the like. In the composition of the present invention, (C) as a polymerizable binder, in addition to the compound having two or more polymerizable unsaturated groups in the molecule as described above, if necessary, in the molecule. A compound having one polymerizable unsaturated group may be contained.

(D) Organic solvent The composition of the present invention preferably contains an organic solvent in order to suppress the thixotropy of the composition and provide the composition with coating properties. By containing an organic solvent, (A) the dispersibility of the modified particles is improved, and the viscosity of the composition (resin liquid) can be adjusted to an appropriate value.

  As the organic solvent (D) used in the present invention, for example, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, or alcohol solvents such as ethanol, isopropyl alcohol and butanol are preferable.

(E) Dispersant The composition of the present invention preferably contains a dispersant in order to uniformly disperse the modified particles (A) in the composition. The thixotropy of the composition can be suppressed only by adding a small amount of a dispersant.

  The (E) dispersant used in the present invention is preferably a comb-shaped organic polymer having a polar group in the side chain, and is an organic polymer having a polyoxyalkylene group in the side chain and an ionic group in the main chain. Is more preferable, and an organic polymer having an alkylene oxide structural unit in the side chain and a carboxylic anhydride structure in the main chain skeleton is more preferable.

(E) Specific examples of the comb-shaped organic polymer having a polar group used as a dispersant include a polymer having a repeating structure represented by the following formula (4).

In formula (4), R ⁶ is a monovalent organic group having a repeating structure composed of an alkylene glycol group such as ethylene oxide or propylene oxide.

  As a commercial item of the comb-shaped organic polymer which has a polar group, Marialim AKM-0531, AAS-0851, AAB-0851, AFB-1521 (above, Nippon Oil & Fats Co., Ltd. product) etc. are mentioned.

(F) Other optional additive components In the present invention, various blending components other than the above, such as a sensitizer, can be blended according to the purpose, if necessary. Examples are listed below.

(F-1) Sensitizer Examples of the sensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, and ethyl 4-dimethylaminobenzoate. And isoamyl 4-dimethylaminobenzoate. Examples of commercially available products of this sensitizer include Nippon Kayaku Co., Ltd. trade names: KAYACURE DMBI, EPA, and the like.

(F-2) Solvent In addition to the organic solvent (D), a solvent can be added after preparing a composition for improving coating properties, adjusting viscosity, adjusting solid content concentration, and the like. As the solvent, the same solvent as that used as the dispersion solvent can be used.

(F-3) (A) Inorganic fine particles other than modified particles (A) Examples of inorganic fine particles other than modified particles include inorganic fine particles that are not bonded to an organic compound.

(F-4) Various additives As additives, for example, antioxidants, ultraviolet absorbers, light stabilizers, silane coupling agents, anti-aging agents, thermal polymerization inhibitors, colorants, leveling agents, surfactants, Examples include storage stabilizers, plasticizers, lubricants, inorganic fillers, organic fillers, fillers, wettability improvers, and coating surface improvers.

Examples of commercially available antioxidants include trade names manufactured by Ciba Specialty Chemicals Co., Ltd .: Irganox 1010, 1035, 1076, 1222, and the like. Examples of ultraviolet absorbers include Ciba Specialty Chemicals Co., Ltd. ) Product name: Tinuvin P, 234, 320, 326, 327, 328, 213, 400, manufactured by Sumitomo Chemical Co., Ltd. Product name: Sumisorb 110, 130, 140, 220, 250, 300, 320, 340, 350 400, and the like. Commercially available light stabilizers are trade names manufactured by Ciba Specialty Chemicals Co., Ltd .: Tinuvin 292, 144, 622LD, trade names manufactured by Sankyo Chemical Industry Co., Ltd .: Sanol LS- 770, 765, 292, 2626, 1114, 744, etc. Examples of the adhesive agent include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane. Examples of these commercially available products include Toray Dow Corning Silicone ( Product name: SH6062, SZ6030, Shin-Etsu Silicone Co., Ltd. Product name: KBE903, KBM803, etc. As commercial products of anti-aging agents, trade name: Antigen W, manufactured by Sumitomo Chemical Co., Ltd. , S, P, 3C, 6C, RD-G, FR, AW, and the like.

(F-5) Additives other than the above As additives other than the above, polymerizable compounds such as epoxy resins, urethane (meth) acrylates, vinyl ethers, propenyl ethers, maleic acid derivatives, polyamides, polyimides, polyamideimides, polyurethanes, Polybutadiene, chloroprene, polyether, polyester, pentadiene derivative, styrene / butadiene / styrene block copolymer, styrene / ethylene / butene / styrene block copolymer, styrene / isoprene / styrene block copolymer, petroleum resin, xylene resin, Examples include polymers or oligomers such as ketone resins, fluorine-based oligomers, silicone-based oligomers, and polysulfide-based oligomers.

I-2. Next, the manufacturing method of the composition of this invention is demonstrated.
The composition of the present invention comprises (A) modified particles, (B) a photoradical reaction initiator, (C) a polymerizable binder, and (D) an organic solvent, (E) a dispersant, and (F) as necessary. Other optional additive components can be produced by mixing in a container shielded from ultraviolet rays under a dry air stream and stirring sufficiently.

I-3. Hereinafter, the compounding quantity of each component which comprises the composition of this invention is demonstrated.
(A) The content of the modified particles is within a range of 50 to 97% by mass, preferably 60 to 95% by mass, and more preferably 70 to 70% by mass, where the total amount of the components (A) to (C) is 100% by mass. It is in the range of 90% by mass. If it exists in the range of 50-97 mass%, the intensity | strength at the time of optical shaping | molding and the shape retainability at the time of ceramic firing can be ensured.

  (B) The content of the photoradical reaction initiator is in the range of 0.1 to 5% by mass, preferably 0.2 to 3% by mass, where the total amount of the components (A) to (C) is 100% by mass. %, And more preferably within the range of 0.3 to 2% by mass. If it exists in the range of 0.1-5 mass%, sufficient sensitivity with respect to the hardening light at the time of optical modeling and the intensity | strength of an optical modeling thing are securable.

  The content of the (C) polymerizable binder is within the range of 2 to 49% by mass, preferably 4 to 35% by mass, more preferably 5 with the total amount of the components (A) to (C) being 100% by mass. It is in the range of ˜25% by mass. If it exists in the range of 2-49 mass%, the intensity | strength at the time of optical shaping | molding and the shape retainability at the time of ceramic firing can be ensured.

  (D) The content of the organic solvent is 10 to 500 parts by weight, preferably 20 to 300 parts by weight, more preferably 50 to 200 parts by weight, with the total of the components (A) to (C) being 100 parts by weight. Within range. If it is in the range of 10 to 500 parts by weight, good coatability can be obtained.

  (E) The content of the dispersant is 0.01 to 10 parts by weight, preferably 0.5 to 5 parts by weight, more preferably 0.8 parts by weight, with the total of the components (A) to (C) being 100 parts by weight. It is in the range of 1 to 3 parts by weight. If it is in the range of 0.01 to 10 parts by weight, good coatability can be obtained.

II. Manufacturing method of ceramic molded body The manufacturing method of the ceramic molded body of the present invention (hereinafter referred to as “method of the present invention”) comprises (1) the ultraviolet curable resin composition for molding ceramics (composition of the present invention). A step of selectively irradiating a part of the layer with ultraviolet rays to cure the ultraviolet curable resin composition for ceramic modeling into a desired shape (hereinafter referred to as “(1) resin curing step” or “step (1)”. And (2) a step of sintering inorganic fine particles in the obtained cured product to form a ceramic molded body (hereinafter referred to as “(2) ceramics sintering step” or “step (2)”). It is characterized by including.

  In the method of the present invention, the above (2) ceramic sintering step is (2-1) the organic component in the cured product is thermally decomposed, but the cured product is heated at a temperature at which the inorganic fine particles are not sintered. And a step of obtaining a ceramic precursor consisting essentially of inorganic fine particles (hereinafter referred to as “(2-1) organic component decomposition step” or “step (2-1)”), (2-2) ) A step of heating the ceramic precursor at a temperature at which the inorganic fine particles are sintered to form a ceramic molded body (hereinafter referred to as “(2-2) inorganic fine particle sintering step” or “step (2-2)”. These steps can more effectively prevent cracking or breakage of the ceramic molded body.

  In the method of the present invention, the (2) ceramic sintering step is fired into the ceramic precursor composed of (2-1) the organic component decomposition step and (2-3) substantially only inorganic fine particles. A step of obtaining a fluid ceramic material-impregnated ceramic precursor by impregnating the fluid ceramic material forming the ceramic by the above (hereinafter referred to as “(2-3) fluid ceramic impregnation step” or “step (2-3)”). And (2-4) a step of heating the fluid ceramic material-impregnated ceramic precursor at a temperature at which the inorganic fine particles and the fluid ceramic material are sintered to form a ceramic molded body (hereinafter referred to as “(2-4) Inorganic fine particles and fluid ceramic material sintering step "or" step (2-4) "). By these steps, generation of cracks in the heating step of step (2-2) can be prevented, and dimensional change can be suppressed, and a more compact and hard ceramic molded body can be obtained.

Hereafter, each process of the method of this invention is demonstrated in detail, referring the flowchart shown in FIG.1 and FIG.2.
(1) Resin curing step A stage (substrate) such as a quartz plate, metal plate, FRP plate or the like for applying the composition of the present invention is prepared (S101), and a weir is placed on the stage so that the composition does not flow down. Provide. On the stage provided with the weir, the composition of the present invention is applied and the solvent is dried to produce a resin film having a thickness of about 0.01 to 3 mm (S103). The composition is selectively selected by concentrating ultraviolet rays at a specific position in the resin film using an optical method, and moving the light collecting portion to an arbitrary position in the resin film three-dimensionally. The product is cured to obtain a cured product having a desired shape (S104).

  The method of the present invention does not perform layered modeling while mechanically sinking the stage of a modeled object, like a general optical modeling method for obtaining a modeled object of the order of millimeters to several tens of centimeters, and is uncured In the layer of the photo-curable resin composition, the position where the curing light is condensed three-dimensionally is moved sequentially (the position where the focal point is focused is controlled three-dimensionally), and the resin is cured at the focal point. Thus, a ceramic molded body having a desired shape on the order of 1 to 1000 μm is produced.

  Examples of the ultraviolet ray source used in the present invention include a mercury lamp, a halide lamp, and a laser. Moreover, the wavelength of the ultraviolet-ray to be used is 220-380 nm normally, Preferably it is 240-380 nm, More preferably, it exists in the range of 320-370 nm.

  Examples of the optical method for condensing ultraviolet rays include an optical device that focuses an image on a resin film via an objective lens, and an optical device that condenses a plurality of ultraviolet laser beams at one point. In order to form a desired three-dimensional shape, the resin film stage is moved vertically and horizontally to change the focal position in the resin film continuously or intermittently, or the resin film stage is fixed. In addition, a method of changing the focal position continuously or intermittently can be used. In the latter case, the moving direction of the stage is limited to the horizontal direction, and the focal position may be changed in the vertical direction, or the focal position may be changed in the vertical and horizontal directions without moving the stage.

(2) Ceramic sintering step This is a step of sintering the cured product cured by the ultraviolet irradiation at a temperature at which the inorganic fine particles sinter to obtain a ceramic molded body. The following steps (2-1) and (2- 2) or the following steps (2-1), (2-3) and (2-4) are preferably included.

(2-1) Organic component decomposition process The hardened | cured material hardened | cured by the said ultraviolet irradiation is wash | cleaned with solvents, such as methyl ethyl ketone (MEK), acetone, ethyl alcohol, isopropyl alcohol, and an uncured resin component is removed (S105). The cured product is put in a crucible, and the organic component is thermally decomposed in a nitrogen atmosphere, but the inorganic fine particles in the composition are heated at a temperature at which the composition is not sintered, and the organic component is decomposed and removed (primary heating). A ceramic precursor composed only of inorganic fine particles is obtained (S106). “The temperature at which the organic component is thermally decomposed but the inorganic fine particles are not sintered” should be appropriately selected according to the conditions such as the type of the inorganic fine particles, the size of the ceramic precursor, the type of the polymerizable binder, Generally, it is in the range of 300 to 800 ° C, preferably in the range of 350 to 600 ° C. In addition, “substantially only consisting of inorganic fine particles” does not mean that the organic component must be completely decomposed and removed, and does not adversely affect the sintering of the ceramic precursor in the following process. It means that a certain amount of organic components may remain.
Specifically, the heating condition in this step starts at room temperature and raises the temperature to about 300 to 800 ° C. at a rate of temperature increase of about 2 ° C. per minute. By this primary heating, only the organic component in the cured product is first decomposed and removed, whereby a ceramic precursor consisting essentially of inorganic fine particles can be obtained.

  The ceramic precursor substantially consisting only of the inorganic fine particles obtained in the step (2-1) has voids inside because the organic component that has bonded the inorganic fine particles is removed. . When this is sintered in the following step (2-2), a dense and high-hardness ceramic is obtained.

(2-2) Inorganic fine particle sintering step Next, a ceramic precursor consisting essentially of inorganic fine particles after the organic components have been decomposed and removed is put into a crucible, and using a high-temperature heating means such as a muffle furnace, Heating is performed at a temperature at which the inorganic fine particles are sintered (secondary heating). “The temperature at which the inorganic fine particles sinter” should be appropriately selected depending on conditions such as the type of inorganic fine particles, the size of the ceramic precursor, and the particle diameter of the inorganic fine particles, but is generally within the range of 1000 to 3000 ° C. , Preferably it is in the range of 1200-2500 degreeC.
Specifically, the heating conditions in this step are as follows: starting at room temperature, increasing the temperature to about 1000 to 3000 ° C. at a rate of temperature increase of about 5 ° C. per minute, and holding at this temperature for about 0.1 to 10 hours Then, the inorganic fine particles are sintered to obtain a ceramic molded body (S107). Thereafter, the ceramic molded body is gradually cooled to room temperature.

(2-3) Fluid ceramic material impregnation step Before the secondary heating of the ceramic precursor consisting essentially of inorganic fine particles obtained in the step (2-1), the ceramic precursor is subjected to firing. A fluid ceramic material impregnating the ceramic is impregnated to obtain a fluid ceramic material-impregnated ceramic precursor (S108). By this step, the fluid ceramic material enters the voids in the ceramic precursor made of substantially only inorganic fine particles and fills the voids. When this is subjected to secondary heating (sintering), the fluid ceramic material is condensed and sintered to be uniformed with the inorganic fine particles, and an extremely dense ceramic molded body is obtained.

  Examples of the fluid ceramic material that forms ceramics by firing include water glass, tetramethoxysilane, hexamethyldisilazane (HMDS), and the like.

  In order to impregnate a ceramic material consisting essentially of inorganic fine particles with a fluid ceramic material, for example, the ceramic precursor is placed in a fluid ceramic material solution (for example, a methanol solution) and 0 ° C. at room temperature. It may be left for about 1 to 5 hours, or a fluid ceramic material may be applied to the ceramic precursor. The procedure for impregnation may be performed once or may be repeated a plurality of times.

(2-4) Sintering process of inorganic fine particles and fluid ceramic material As described above, the ceramic precursor is impregnated with the fluid ceramic material, dried, and then placed in a crucible, and then the inorganic fine particles and the fluid ceramic material. Secondary heating is performed at the temperature at which the ceramic is sintered to obtain a ceramic molded body (S109). “The temperature at which the inorganic fine particles and the fluid ceramic material sinter” should be appropriately selected according to the conditions such as the kind of the inorganic fine particles and the fluid ceramic material, the size of the ceramic precursor, and the particle diameter of the inorganic fine particles. Is generally in the range of 1000 to 3000 ° C, preferably in the range of 1200 to 2500 ° C. Specific heating conditions are the same as in the above step (2-2).

  According to the method of the present invention, a ceramic molded body having a fine and complicated shape can be obtained, and the obtained ceramic molded body is effectively prevented from being cracked or damaged by curing shrinkage.

III. Ceramic Precursor The ceramic precursor having a desired shape and the ceramic precursor impregnated with a fluid ceramic material, which are substantially composed only of inorganic fine particles having an average particle diameter of 5 to 70 nm, as described in the method of the present invention, are: A ceramic material having a novel structure. By heating these ceramic precursors at a temperature at which the inorganic fine particles or the inorganic fine particles and the fluid ceramic material are sintered, a fine and complex shaped ceramic molded body can be obtained.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Hereinafter, unless otherwise indicated, parts and% represent parts by mass and% by mass, respectively.

<Synthesis of chemically modifying reagents for introducing polymerizable unsaturated groups into inorganic fine particles>
Preliminary synthesis example 1
To a solution consisting of 7.8 parts of mercaptopropyltrimethoxysilane and 0.2 part of dibutyltin dilaurate in dry air, 20.6 parts of isophorone diisocyanate was added dropwise at 50 ° C. over 1 hour with stirring, followed by 60 ° C. For 3 hours. To this, 71.4 parts of pentaerythritol triacrylate was added dropwise at 30 ° C. over 1 hour, and the mixture was heated and stirred at 60 ° C. for 3 hours to obtain compound (B1). In the infrared absorption spectrum of the product, the absorption peak of 2550 cm ⁻¹ characteristic of the mercapto group in the raw material and the absorption peak of 2260 cm ⁻¹ characteristic of the isocyanate group disappeared. -O-C (= O) -NH- ] group and [-S-C (= O) -NH-] of the characteristic 1660 cm ^-1 based on peak - to click and acryloyl groups characteristic 1720 cm ^-1 A peak is observed, and an organic group having both an acryloyl group as a polymerizable unsaturated group, a [—S—C (═O) —NH—] group, and a [—O—C (═O) —NH—] group. It was confirmed that the compound was produced.

<Preparation of modified particles>
Synthesis example 1
Under nitrogen flow, methanol silica sol (manufactured by Nissan Chemical Industries, Ltd., trade name: Snowtex methanol silica sol (number average particle size 12 nm, methanol dispersion of silica sol, silica concentration 30%)) 90.0 parts, preliminary synthesis example 1 A mixture of 8.5 parts of the compound (B1) synthesized in step 1 and 0.1 part of p-methoxyphenol was stirred at 60 ° C. for 4 hours, and then 1.4 parts of methyl orthoformate was added. The modified particle dispersion (P1) was obtained by heating and stirring at the same temperature for the time.

Synthesis example 2
Methanol alumina sol (methanol dispersion but water remains, water-based alumina sol (Cai Kasei Co., Ltd., water dispersion of alumina sol) produced by solvent substitution. Number average particle size 7.5 nm, alumina concentration 30%, moisture (5.6%) A mixture of 90.0 parts, 8.5 parts of the compound (B1) synthesized in Preliminary Synthesis Example 1 and 0.1 part of p-methoxyphenol was stirred at 60 ° C. for 3 hours. Subsequently, 1.4 parts of methyltriethoxysilane (A-3) polymerizable unsaturated group-free compound was added to the reaction mixture, stirred at 60 ° C. for 1 hour, and then added with 9 parts of methyl orthoformate. Then, the modified particle dispersion (P2) was obtained by further heating and stirring at the same temperature for 1 hour.

Synthesis example 3
Under nitrogen stream, ethylene glycol silica sol (manufactured by Nissan Chemical Industries, Ltd., trade name: Snowtex EG-ST-ZL (number average particle size 100 nm, ethylene glycol dispersion of silica sol, silica concentration 20%)) 135.0 parts Then, 8.5 parts of the compound (B1) synthesized in Preparative Synthesis Example 1 and 0.1 part of p-methoxyphenol were stirred at 60 ° C. for 4 hours, and then 1.4 parts of orthoformate methyl ester was added. The resulting mixture was further heated and stirred at the same temperature for 1 hour to obtain a modified particle dispersion (P3).

Comparative Synthesis Example 1
An inorganic fine particle dispersion (CP1) was obtained under the same conditions as in Synthesis Example 1 except that the compound (B1) synthesized in Preliminary Synthesis Example 1 was not used.

<Preparation of UV curable resin composition for ceramic modeling>
The following compositions were prepared using the modified particle dispersion and the inorganic fine particle dispersion prepared in Synthesis Examples 1 to 3 and Comparative Synthesis Example 1 (Examples 1 to 4 and Comparative Example 1).

Example 1
In a dry air stream, in a container shielded from ultraviolet rays, 1.5 parts of 1-hydroxycyclohexyl phenyl ketone is added at room temperature to 98.5 parts of the modified particle dispersion (dispersion P1) produced in Synthesis Example 1 at room temperature. The composition (composition Q1) was obtained by stirring for minutes.

Example 2
A composition (composition Q2) was obtained in the same manner as in Example 1 except that the dispersion P2 produced in Synthesis Example 2 was used as the modified particle dispersion.

Example 3
A composition (composition Q2) was obtained in the same manner as in Example 1 except that the dispersion P3 produced in Synthesis Example 3 was used as the modified particle dispersion.

Example 4
In a container shielded from ultraviolet rays in a dry air stream, 10 parts of dipentaerythritol hexaacrylate, 1-hydroxycyclohexyl phenyl ketone 1.5 with respect to 87 parts of the modified particle dispersion (dispersion P1) produced in Synthesis Example 1. And 1.5 parts of 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 were stirred at room temperature for 30 minutes to obtain a composition (Composition Q4).

Comparative Example 1
A composition (composition CQ1) was obtained in the same manner as in Example 1, except that the inorganic fine particle dispersion CP1 produced in Comparative Synthesis Example 1 was used instead of the modified particle dispersion (dispersion P1).

<Manufacture of ceramic moldings>
Ceramic molded bodies were produced using the compositions prepared in Examples 1 to 4 and Comparative Example 1 (Examples 5 to 9 and Comparative Example 2).

Example 5
A silicon rubber weir was provided on the quartz plate, and after pouring the composition Q1 obtained in Example 1, the solvent was dried to obtain a resin film having a thickness of 1 mm. The resin was cured by an optical device that uses a He—Cd laser with a wavelength of 325 nm as a light source and focuses the image in the resin film through an objective lens. The quartz plate was moved up and down, left and right, and the focal position in the resin film was changed continuously or intermittently to cure, thereby irradiating the resin film with ultraviolet rays at a 500 μm square shape position. After UV curing, the resin was washed with methyl ethyl ketone (MEK) to remove the uncured resin, thereby obtaining a cubic three-dimensional shape of 500 μm square.

  The obtained three-dimensional shaped product was put in a crucible and heated from room temperature to 500 ° C. under nitrogen at a heating rate of 2 ° C. per minute to decompose the organic components in the cured product. A 470 μm square cubic shaped product was confirmed by microscopic observation.

  The cube-shaped product was placed in a crucible, heated from room temperature to 1400 ° C. at 5 ° C. per minute using a muffle furnace, held at 1400 ° C. for 1 hour, and then gradually cooled to room temperature. A 410 μm square cubic shaped ceramic molded body was confirmed by microscopic observation.

Example 6
The composition Q2 obtained in Example 2 was applied onto a quartz plate in the same manner as in Example 5 and dried to obtain a resin film having a thickness of 1 mm. A 500 μm square cubic three-dimensional shape product was obtained in the same manner as in Example 5.

  The obtained three-dimensional object was put in a crucible and heated from room temperature to 500 ° C. under nitrogen at a rate of 2 ° C. per minute to decompose the organic components. A cube-shaped product having a 420 μm square was confirmed by microscopic observation.

  The cube-shaped product was placed in a crucible, heated from room temperature to 1800 ° C. at 5 ° C. per minute using a muffle furnace, held at 1800 ° C. for 1 hour, and then gradually cooled to room temperature. A 370 μm square cubic shaped ceramic molded body was confirmed by microscopic observation.

Example 7
The composition Q3 obtained in Example 3 was applied onto a quartz plate in the same manner as in Example 5 and dried to obtain a resin film having a thickness of 1 mm. In the same manner as in Example 5, ultraviolet rays were irradiated to the positions of a 500 μm square cube in the resin film. After UV curing, it was washed with MEK to remove uncured resin, and a hemispherical three-dimensional product having a bottom diameter of 700 μm and a height of 350 μm was obtained.

  The obtained three-dimensional object was put in a crucible and heated from room temperature to 500 ° C. under nitrogen at a rate of 2 ° C. per minute to decompose the organic components. Microscopic observation confirmed a hemispherical shape with a bottom width and depth of 660 μm each and a height of 330 μm.

  The hemispherical shaped product was placed in a crucible, heated from room temperature to 1400 ° C. at 5 ° C. per minute using a muffle furnace, held at 1400 ° C. for 1 hour, and then gradually cooled to room temperature. A hemispherical three-dimensional ceramic molded body having a bottom diameter of 580 μm and a height of 290 μm was confirmed by microscopic observation.

Example 8
The composition Q4 obtained in Example 4 was applied onto a quartz plate in the same manner as in Example 5 and dried to obtain a resin film having a thickness of 1 mm. A 500 μm square cubic three-dimensional shape product was obtained in the same manner as in Example 5.

  The obtained three-dimensional object was put in a crucible and heated from room temperature to 500 ° C. under nitrogen at a rate of 2 ° C. per minute to decompose the organic components. A 400 μm square cubic shape was confirmed by microscopic observation.

  The cube-shaped product was placed in a crucible, heated from room temperature to 1400 ° C. at 5 ° C. per minute using a muffle furnace, held at 1400 ° C. for 1 hour, and then gradually cooled to room temperature. A 350 μm square ceramic molded body was confirmed by microscopic observation.

Example 9
The 500 μm square cubic three-dimensional product obtained in Example 5 was placed in a crucible and heated from room temperature to 500 ° C. under nitrogen at a rate of 2 ° C. per minute to decompose the organic components. A 470 μm square cubic shaped product was confirmed by microscopic observation.

  The cube-shaped product was left in a 50% methanol solution of tetramethoxysilane at room temperature for 2 hours. The cube-shaped product was taken out and dried, and then again left in a 50% methanol solution of tetramethoxysilane at room temperature for 2 hours. The cube-shaped product was taken out again and dried, then placed in a crucible and heated from room temperature to 1400 ° C. at 5 ° C. per minute using a muffle furnace, held at 1400 ° C. for 1 hour, and then gradually cooled to room temperature. A 450 μm square cubic shaped ceramic molded body was confirmed by microscopic observation.

Comparative Example 2
A resin film having a thickness of 1 mm was applied on a quartz plate and dried in the same manner as in Example 5 except that the composition CQ1 obtained in Comparative Example 1 was used instead of the composition Q2 obtained in Example 2. Got. A 500 μm square cubic three-dimensional shape product was obtained in the same manner as in Example 5.

  Put the three-dimensional object in the crucible. The organic matter was decomposed by heating from room temperature to 500 ° C. at a heating rate of 2 ° C. per minute under nitrogen. As a result of microscopic observation, a cubic shaped product was not confirmed, and a finely pulverized product that was thought to be a residue was observed.

  From the results of Examples 5 to 9 and Comparative Example 2, the ceramic molded body produced according to the method for producing a ceramic molded body of the present invention using the ultraviolet curable resin composition for ceramic modeling of the present invention is fine and shaped. It became clear that it was excellent in accuracy.

  The ultraviolet curable resin composition for modeling ceramics of the present invention is useful for producing a fine and complex ceramic molded body.

  According to the method for producing a ceramic molded body of the present invention, cracks and breakage due to curing shrinkage can be effectively prevented, the yield of the ceramic product can be improved, and the ceramic product can be advantageously produced in terms of industrial economy.

  The ceramic molded body obtained by the present invention can be used as a fine structure that is difficult to produce by conventional techniques, for example, a component of a micromachine.

FIG. 1 is a flowchart for explaining an outline of a method for producing a ceramic molded body according to the present invention. FIG. 2 is a flowchart illustrating an embodiment of the method for producing a ceramic molded body according to the present invention, in which sintering is performed after impregnating a fluid ceramic material.

Claims (7)

  (1) Ultraviolet light is condensed at a specific position of a layer made of an ultraviolet curable resin composition containing inorganic fine particles using an optical method, and the light condensing portion is arbitrarily arranged in the layer three-dimensionally. (2) sintering the inorganic fine particles in the obtained cured product, and a step of curing the ultraviolet curable resin composition to a desired shape by selectively irradiating ultraviolet rays by moving to the position of A method for producing a ceramic molded body including a step of forming a ceramic molded body.   The method for producing a ceramic molded body according to claim 1, wherein the inorganic fine particles have a polymerizable unsaturated group.   The step of (2) sintering the inorganic fine particles in the obtained cured product to form a ceramic molded body, (2-1) the organic component in the cured product is thermally decomposed, but the inorganic fine particles are sintered. Heating the cured product at a temperature not to decompose organic components to obtain a ceramic precursor consisting essentially of inorganic fine particles, and (2-2) sintering the ceramic precursor with inorganic fine particles. The method for producing a ceramic molded body according to claim 1, comprising a step of heating at a temperature to form a ceramic molded body.   The step of (2) sintering the inorganic fine particles in the obtained cured product to form a ceramic molded body, (2-1) the organic component in the cured product is thermally decomposed, but the inorganic fine particles are sintered. Heating the cured product at a temperature not to decompose organic components to obtain a ceramic precursor consisting essentially of inorganic fine particles, and (2-3) a flow of forming ceramics on the ceramic precursor by firing. A step of obtaining a fluid ceramic material-impregnated ceramic precursor by impregnating the fluid ceramic material; and (2-4) the fluid ceramic material-impregnated ceramic precursor at a temperature at which the inorganic fine particles and the fluid ceramic material are sintered. The manufacturing method of the ceramic molded body of Claim 1 or 2 including the process of heating and setting it as a ceramic molded body.   A ceramic precursor having a desired shape substantially composed only of inorganic fine particles having an average particle diameter of 5 to 70 nm.   A fluid ceramic material-impregnated ceramic precursor, wherein the ceramic precursor according to claim 5 is impregnated with a fluid ceramic material that forms ceramics by firing.   A ceramic molded body having a desired shape substantially composed only of inorganic fine particles having an average particle diameter of 5 to 70 nm.