JP6033850B2 - Optical three-dimensional modeling resin composition containing thermally expandable microcapsules - Google Patents

Description

  The present invention relates to a resin composition for optical three-dimensional modeling containing thermally expandable microcapsules.

  Patent Document 1 describes the production of a resin mold using a disappearing core. The foamed polystyrene fine particles are mixed with the two-component reaction-curable soft urethane resin liquid, and the obtained mixture is cast into a mold for forming a core having a recess to be cured to obtain a urethane resin. Thereafter, the cured urethane resin is removed from the mold for forming the core, thereby producing the disappearing core. The disappearing core is placed in a mold for resin mold production, and a two-component reaction rapid-curing urethane resin liquid is poured into the mold and cured, and then the cured urethane resin is used for resin mold production. A resin mold is produced by removing the mold from the mold. The disappearing core is removed by injecting an expanded polystyrene-soluble organic solvent into the disappearing core in the resin mold to dissolve the expanded polystyrene fine particles. In this way, a resin mold is manufactured. However, in this case, since the disappearing core is manufactured by casting, even if the expanded polystyrene fine particles are used, it is not possible to manufacture the disappearing core having an extremely complicated shape, structure, or extremely small size. Have difficulty. Moreover, in order to remove the disappearing core from the resin mold, it is necessary to dissolve and remove the foamed polystyrene forming the core with an organic solvent.

  In Patent Document 2, a thin-walled hollow body having a shape corresponding to the shape of the disappearance model is produced using an optical modeling technique, and an unfoamed foam material is put into the thin-walled hollow body and foamed. Describes filling the inside of a thin-walled hollow body with a foaming material, and removing the photocurable resin in a photocured state after the foaming material is cured to produce a disappeared model.

  In this case, since the stereolithography technique is used, a disappearing core having a complicated shape can be manufactured. However, production of a thin hollow body by stereolithography, filling and foaming of the foamable material into the thin hollow body, and removal of the photocured resin (the thin hollow body produced first) from the foamed material Since it is necessary to employ a multi-stage process, the manufacturing process of the lost core is complicated and time-consuming.

  In Patent Document 3, a hollow core manufactured by stereolithography is placed in an outer mold, and a liquid soft resin material is injected into a gap between the core and the outer mold to be solidified to form a soft resin molded body. After the soft resin molded body is taken out from the outer mold together with the core, the core is deformed and made smaller by deforming the soft resin molded body by applying a force from the outside of the soft resin molded body and / or Alternatively, it has been proposed to produce a soft resin molded body by discharging a crushed and deformed core or a crushed core from the opening of the soft resin molded body to the outside.

  In this case, since the core is manufactured by stereolithography, it is possible to manufacture a core having a complicated shape, and when the core is taken out, the soft resin molded body obtained by molding is externally provided. Since the core contained in the resin molded body is reduced or crushed by applying force from the opening of the flexible resin molded body, it is not necessary to dissolve and disappear the core using an organic solvent. The removal of the core is easy.

  However, in this method, if the wall thickness of the hollow core is too thick, the core is less likely to be small when pressed from the outside of the soft resin molded body, and the core is less likely to be crushed. Since it becomes difficult to discharge the core from the body, it is necessary to reduce the wall thickness of the hollow core. When the wall thickness of the hollow core is reduced, when the core is placed in the outer mold and the soft resin material is injected, the core may be deformed or in some cases the core may be damaged. It becomes difficult to obtain a soft resin molded body having a shape and dimensions.

JP 2004-261816 A JP-A-5-131243 WO2012 / 001803 JP 2008-195985 A JP 2011-16884 A WO99 / 43758

  The object of the present invention is to satisfactorily manufacture even a core having a complicated shape or structure or other three-dimensional modeled object. The three-dimensional modeled object can be used as a core or used for other purposes. Provided is a resin material that can produce a three-dimensional model that is excellent in strength, shape retention and handling properties, is not damaged or deformed, and can be easily removed after use. That is.

  The inventors of the present invention have made various studies in order to achieve the above-described object, and have come to think of including thermally expandable microcapsules in the optical three-dimensional resin composition. Accordingly, a resin composition for optical three-dimensional modeling containing a photopolymerizable compound, a photopolymerization initiator, and a heat-expandable microcapsule is manufactured, and the resin composition for optical three-dimensional modeling is used to produce a heat-expandable microcapsule. A three-dimensional object was manufactured by performing optical three-dimensional modeling under conditions where expansion did not occur. The three-dimensional object obtained by this method was excellent in strength, shape retention, and handleability even if it contained a heat-expandable microcapsule, but the heat-expandable microcapsule contained in the optical three-dimensional object When heated to a temperature at which the three-dimensional model is expanded, even if the entire three-dimensional model is foamed and collapses or does not collapse, the strength of the three-dimensional model is greatly reduced and easily collapses. The present invention has been completed by finding that the product is extremely effective as a master model for producing a molded body or mold by a core or casting.

That is, the present invention
(1) A resin composition for optical three-dimensional modeling containing a photopolymerizable compound, a photopolymerization initiator, and a thermally expandable microcapsule.

The present invention also provides:
(2) The resin composition for optical three-dimensional modeling according to (1), wherein the thermally expandable microcapsules do not expand during optical three-dimensional modeling; and
(3) The resin composition for optical three-dimensional modeling of the above (1) or (2), which is for producing a three-dimensional modeled product containing the thermally expandable microcapsules in an unexpanded state;
It is.

Furthermore, the present invention provides
(4) The thermally expandable microcapsule includes an outer shell made of a thermoplastic polymer and a volatile liquid expander encapsulated in the outer shell, and has an average particle diameter of 1 to 100 μm ( A resin composition for optical three-dimensional modeling according to any one of 1) to (3); and
(5) Said (1)-(4) whose content of a thermally expansible microcapsule is 20-80 mass parts with respect to 100 mass parts of all the photopolymerizable compounds contained in the resin composition for optical three-dimensional model | molding. ) Any one of the resin compositions for optical three-dimensional modeling;
It is. That is, this optical three-dimensional modeling resin composition includes 100 parts by mass of a photopolymerizable compound and 20 to 80 parts by mass of thermally expandable microcapsules.

Furthermore, the present invention provides
(6) For optical three-dimensional modeling according to any one of (1) to (5), wherein the photopolymerizable compound is selected from one or more radical polymerizable compounds, one or more cationic polymerizable compounds, or both. Resin composition;
(7) The resin composition for optical three-dimensional modeling according to any one of (1) to (6), wherein the photopolymerizable compound is a radical polymerizable compound and the photopolymerization initiator is a photoradical polymerization initiator;
(8) The resin composition for optical three-dimensional modeling according to (6) or (7), wherein the radical polymerizable compound is a di (meth) acrylate compound having two (meth) acryloyloxy groups;
(9) For optical three-dimensional modeling of (8), wherein the di (meth) acrylate compound having two (meth) acryloyloxy groups is a di (meth) acrylate of a substituted or unsubstituted bisphenol. Resin composition;
(10) The resin composition for optical three-dimensional modeling according to any one of (7) to (9), wherein the radical photopolymerization initiator is benzyl or a dialkyl acetal compound thereof; and
(11) The resin composition for optical three-dimensional modeling according to any one of (1) to (10), further containing a polyalkylene ether compound;
It is.

  Using the resin composition for optical three-dimensional modeling of any one of (1) to (11), optical three-dimensional modeling is performed under conditions where expansion of the heat-expandable microcapsule does not occur. An optical three-dimensional model including the unexpanded state can be manufactured.

  An optical three-dimensional modeled article containing thermal expandable microcapsules in an unexpanded state obtained by optical three-dimensional modeling using the resin composition for optical three-dimensional model modeling according to any one of (1) to (11). Is used as a core or the like, and the core or the like is heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule, whereby a hollow molded body or a mold can be produced.

  Further, optical three-dimensional modeling is performed using the resin composition for optical three-dimensional modeling of the present invention to produce a hollow molded body, and the hollow molded body is used as a master model, and an organic weight is formed inside the master model. A hollow molded body (master model) formed from a resin composition for optical three-dimensional modeling on the outside after injecting or filling a solid body (for example, silicone rubber, silicone resin, other polymer) or other material to solidify. By heating above the expansion start temperature of the thermally expandable microcapsule and foaming and collapsing, a mold made of an organic polymer and other materials and a molded body that can be used for other applications can be produced.

  By using the resin composition for optical three-dimensional model | molding of this invention, the foamable three-dimensional model | molding thing containing a thermally expansible microcapsule which is excellent in intensity | strength, shape retention property, and handleability can be manufactured smoothly.

  By performing optical three-dimensional modeling using the resin composition for optical three-dimensional modeling of the present invention, a three-dimensional modeled object or a minute three-dimensional modeled object having a complicated shape or structure containing a thermally expandable microcapsule is also obtained. It can be manufactured easily and smoothly.

  The three-dimensional model obtained by performing the optical three-dimensional model using the optical three-dimensional model resin composition of the present invention is included in the three-dimensional model by heating above the expansion start temperature of the thermally expandable microcapsule. As the thermally expandable microcapsule expands, the entire three-dimensional structure foams and collapses or easily collapses, so various hollow molded bodies, cores for producing hollow products, It can be effectively used as a core for producing a mold used for producing various molded articles (various products).

  Here, “three-dimensional model foams and collapses” in this specification means that the three-dimensional model foams and directly becomes a strip-like foam, or the three-dimensional model foams with a small external force. It means that it becomes a foam having no shape retaining property that easily collapses into a strip shape, or a foam that has no shape retaining property and can easily reduce its volume with a small external force.

FIG. 1 shows the production of a hollow molded body using a core (three-dimensional model) obtained by optical modeling using the resin composition for optical three-dimensional modeling of the present invention containing thermally expandable microcapsules. It is the figure which showed an example of the case. FIG. 2 is a drawing-substituting photograph showing a foamed state when the optical three-dimensional structure (bar-shaped test piece) obtained in Example 1 is heated at 150 ° C. for 10 minutes. FIG. 3 is a drawing-substituting photograph showing a foamed state when the optical three-dimensional object (bar-shaped test piece) obtained in Example 2 is heated at 150 ° C. for 10 minutes. FIG. 4 is a drawing-substituting photograph showing a state when the optical three-dimensional structure (bar-shaped test piece) obtained in Reference Example 1 is heated at 150 ° C. for 10 minutes.

The present invention is described in detail below.
The resin composition for optical three-dimensional model | molding of this invention contains a photopolymerizable compound, a photoinitiator, and a thermally expansible microcapsule.

  As a photopolymerizable compound, a three-dimensional model that foams when a three-dimensional model obtained by optical three-dimensional modeling (hereinafter sometimes referred to as “photo-modeling”) is heated to the expansion temperature of a thermally expandable microcapsule is manufactured. As long as it is a photopolymerizable compound that can be used, one or more radically polymerizable compounds, one or more cationically polymerizable compounds, or both conventionally used in resin compositions for optical three-dimensional modeling are used. be able to.

  Examples of the radical polymerizable organic compound include a compound having a (meth) acrylate group, an unsaturated polyester compound, an allylurethane compound, and a polythiol compound. One or more of these radically polymerizable organic compounds can be used. Among these, a compound having at least one (meth) acryloyloxy group in one molecule is preferably used. Specific examples of the compound having a (meth) acryloyloxy group include a reaction product of an epoxy compound and (meth) acrylic acid, a (meth) acrylic acid ester of an alcohol, a urethane (meth) acrylate, and a polyester (meth) acrylate. And polyether (meth) acrylate.

  As a reaction product of the above-mentioned epoxy compound and (meth) acrylic acid, it can be obtained by reaction of an aromatic epoxy compound, an alicyclic epoxy compound and / or an aliphatic epoxy compound with (meth) acrylic acid (meta) ) Acrylate reaction products. Specific examples of this (meth) acrylate reaction product include bisphenol compounds such as bisphenol A and bisphenol S, substituted bisphenol compounds such as bisphenol A and bisphenol S in which the benzene ring has a substituent such as an alkoxy group, and their (Meth) acrylate and epoxy novolac resin obtained by further reacting glycidyl ether obtained by reacting an alkylene oxide adduct of a bisphenol compound or a substituted bisphenol compound with an epoxidizing agent such as epichlorohydrin, and (meth) acrylic acid And (meth) acrylate reaction products obtained by reacting (meth) acrylic acid.

  In addition, as the (meth) acrylic acid esters of the alcohols described above, aromatic alcohols, aliphatic alcohols, alicyclic alcohols and / or their alkylene oxide adducts having at least one hydroxyl group in the molecule are: Mention may be made of (meth) acrylates obtained by reacting with (meth) acrylic acid.

  More specifically, for example, bisphenol compounds such as bisphenol A and bisphenol S, di (meth) acrylates of substituted bisphenol compounds such as bisphenol A and bisphenol S in which the benzene ring has a substituent such as an alkoxy group, 2-ethylhexyl ( (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isooctyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl ( (Meth) acrylate, benzyl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, diethylene glycol di (Meth) acrylate, triethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, (meth) acrylate of an alkylene oxide adduct of a polyhydric alcohol such as diol, triol, tetraol and hexaol described above.

  Among them, as the (meth) acrylate of alcohols, (meth) acrylate having two (meth) acryl groups in one molecule obtained by reacting a dihydric alcohol with (meth) acrylic acid is preferably used. It is done.

  Examples of the urethane (meth) acrylate described above include (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylic acid ester with an isocyanate compound. As the hydroxyl group-containing (meth) acrylic acid ester, a hydroxyl group-containing (meth) acrylic acid ester obtained by an esterification reaction of an aliphatic dihydric alcohol and (meth) acrylic acid is preferable. As a specific example, 2-hydroxy Examples thereof include ethyl (meth) acrylate. Moreover, as said isocyanate compound, the polyisocyanate compound which has a 2 or more isocyanate group in 1 molecule like tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate etc. is preferable.

  Furthermore, examples of the polyester (meth) acrylate described above include polyester (meth) acrylate obtained by a reaction between a hydroxyl group-containing polyester and (meth) acrylic acid.

Moreover, as above-mentioned polyether (meth) acrylate, the polyether acrylate obtained by reaction of a hydroxyl-containing polyether and acrylic acid can be mentioned.
Specific examples of the cationically polymerizable organic compound include
(1) Epoxy compounds such as alicyclic epoxy resins, aliphatic epoxy resins, aromatic epoxy resins;
(2) trimethylene oxide, 3,3-dimethyloxetane, 3,3-dichloromethyloxetane, 3-methyl-3-phenoxymethyloxetane, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] Oxetane compounds such as benzene, oxolane compounds such as tetrahydrofuran, 2,3-dimethyltetrahydrofuran, cyclic ethers or cyclic acetal compounds such as trioxane, 1,3-dioxolane, 1,3,6-trioxane cyclooctane;
(3) cyclic lactone compounds such as β-propiolactone and ε-caprolactone;
(4) thiirane compounds such as ethylene sulfide and thioepichlorohydrin;
(5) Thiethane compounds such as 1,3-propyne sulfide and 3,3-dimethylthietane;
(6) Vinyl ether compounds such as ethylene glycol divinyl ether, alkyl vinyl ether, 3,4-dihydropyran-2-methyl (3,4-dihydropyran-2-carboxylate), triethylene glycol divinyl ether;
(7) Spiro orthoester compound obtained by reaction of epoxy compound and lactone;
(8) ethylenically unsaturated compounds such as vinylcyclohexane, isobutylene, polybutadiene;
And so on.

  Among the above, as the cationically polymerizable organic compound, an epoxy compound is preferably used, and a polyepoxy compound having two or more epoxy groups in one molecule is more preferably used. As a cationically polymerizable organic compound, an alicyclic polyepoxy compound having two or more epoxy groups in one molecule is contained, and the content of the alicyclic polyepoxy compound is 30 mass based on the total mass of the epoxy compound. %, Especially 50% by mass or more of an epoxy compound (a mixture of epoxy compounds) gives good cationic polymerization rate, thick film curability, resolution, active energy ray permeability, etc. when producing a three-dimensional model. Moreover, the viscosity of the resin composition for optical three-dimensional modeling becomes low and modeling is performed smoothly, and the volumetric shrinkage of the three-dimensional model obtained is further reduced.

  Examples of the alicyclic epoxy resins include polyglycidyl ethers of polyhydric alcohols having at least one alicyclic ring, or cyclohexene or cyclopentene ring-containing compounds with an appropriate oxidizing agent such as hydrogen peroxide or peracid. Examples thereof include cyclohexene oxide or cyclopentene oxide-containing compounds obtained by conversion. More specifically, as the alicyclic epoxy resin, for example, hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl- 5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene dioxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6) -Methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3,4-epoxy-6-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide Mention may be made of di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, etc. it can.

  Examples of the aliphatic epoxy resins include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, polyglycidyl esters of aliphatic long-chain polybasic acids, homopolymers and copolymers of glycidyl acrylate and glycidyl methacrylate. And so on. More specifically, for example, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol tetraglycidyl ether, Obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, diglycidyl ether of polypropylene glycol, ethylene glycol, propylene glycol, glycerin Examples thereof include polyglycidyl ethers of polyether polyols and diglycidyl esters of aliphatic long-chain dibasic acids. In addition to the above epoxy compounds, for example, monoglycidyl ethers of higher aliphatic alcohols, glycidyl esters of higher fatty acids, epoxidized soybean oil, butyl epoxy stearate, octyl epoxy stearate, epoxidized linseed oil, epoxidized polybutadiene And so on.

  Examples of the aromatic epoxy resin include mono- or polyglycidyl ethers of mono- or polyhydric phenols having at least one aromatic nucleus or alkylene oxide adducts thereof. Glycidyl ether, epoxy novolac resin, phenol, cresol, butylphenol obtained by reaction of bisphenol A, bisphenol F or its alkylene oxide adduct with epichlorohydrin, or monoglycidyl ether of polyether alcohol obtained by adding alkylene oxide to these And so on.

  When the resin composition for optical three-dimensional modeling contains a cationically polymerizable compound composed of an epoxy compound, the reaction rate of the cationically polymerizable compound is slow, and modeling takes time. However, if an oxetane compound is added, cationic polymerization is performed. The reaction is promoted.

  As the oxetane compound in that case, an oxetane monoalcohol compound having one or more oxetane groups and one alcoholic hydroxyl group in one molecule is preferably used. As a specific example, 3-hydroxymethyl-3- Methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxymethyl-3-normalbutyloxetane, 3-hydroxymethyl-3-phenyloxetane, 3-hydroxymethyl-3 -Benzyloxetane, 3-hydroxyethyl-3-methyloxetane, 3-hydroxyethyl-3-ethyloxetane, 3-hydroxyethyl-3-propyloxetane, 3-hydroxyethyl-3-phenyloxetane, 3-hydroxypropyl-3 -Methyloxe , 3-hydroxypropyl-3-ethyloxetane, 3-hydroxypropyl-3-propyloxetane, 3-hydroxypropyl-3-phenyloxetane, 3-hydroxybutyl-3-methyloxetane, and the like. One or more types can be used.

  The resin composition for optical three-dimensional model | molding of this invention may contain the polyoxetane compound which has 2 or more of oxetane groups in 1 molecule, and does not have an alcoholic hydroxyl group as needed. When the polyoxetane compound is contained, the dimensional accuracy of the resulting three-dimensional structure is improved.

  Examples of compounds having two or more oxetane groups in one molecule include 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis (3-ethyl-3- And oxetanylmethoxy) butane.

When the resin composition for optical three-dimensional model | molding of this invention contains a radically polymerizable compound as a photopolymerizable compound, a radical photopolymerization initiator is contained as a photoinitiator.
Examples of the photo radical polymerization initiator that can be used in the resin composition for optical three-dimensional modeling of the present invention include benzyl or its dialkyl acetal compound, acetophenone compound, benzoin or its alkyl ether compound, benzophenone compound, and thioxanthone. And the like.

  Specifically, examples of benzyl or a dialkyl acetal compound thereof include benzyl dimethyl ketal, benzyl-β-methoxyethyl acetal, 1-hydroxycyclohexyl phenyl ketone, and the like.

  Examples of the acetophenone compound include diethoxyacetophenone, 2-hydroxymethyl-1-phenylpropan-1-one, 4′-isopropyl-2-hydroxy-2-methyl-propiophenone, and 2-hydroxy-2. -Methyl-propiophenone, p-dimethylaminoacetophenone, p-tert-butyldichloroacetophenone, p-tert-butyltrichloroacetophenone, p-azidobenzalacetophenone and the like.

  Furthermore, examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin normal butyl ether, and benzoin isobutyl ether.

  Examples of the benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, Michler's ketone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, and the like.

  Examples of the thioxanthone compound include thioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, and 2-isopropylthioxanthone.

These photo radical polymerization initiators may be used alone or in combination of two or more.
When the resin composition for optical three-dimensional model | molding of this invention contains a cationically polymerizable compound as a photopolymerizable compound, a photocationic polymerization initiator is contained as a photoinitiator.

  As the cationic polymerization initiator, any polymerization initiator capable of initiating cationic polymerization of the cationic polymerizable compound can be used. Specific examples of the cationic photopolymerization initiator include an onium salt that releases a Lewis acid when irradiated with light, such as an aromatic sulfonium salt of a Group VIIa element, an aromatic onium salt of a Group VIa element, and a Group Va element. Aromatic onium salts of More specifically, for example, triphenylphenacylphosphonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, bis- [4- (diphenylsulfonio) phenyl] sulfide bisdihexafluoroantimonate, bis- [ 4- (di4′-hydroxyethoxyphenylsulfonio) phenyl] sulfide bisdihexafluoroantimonate, bis- [4- (diphenylsulfonio) phenyl] sulfide bisdihexafluorophosphate, diphenyltetrafluoroborate Examples thereof include non-antimony aromatic sulfonium compounds having iodonium and fluorophosphoric acid as counter ions, and one or more of these can be used.

  In addition, for the purpose of improving the reaction rate, a photosensitizer such as benzophenone, benzoin alkyl ether, thioxanthone or the like may be used together with the cationic polymerization initiator as necessary.

The amount of the radical photopolymerization initiator used is preferably 0.5 to 10% by mass, particularly 1 to 5% by mass, based on the mass of the radical polymerizable compound.
Moreover, it is preferable that the usage-amount of a photocationic polymerization initiator is 0.5-10 mass% based on the mass of a cationically polymerizable compound, especially 1-5 mass%.

  In particular, it contains dimethacrylate of substituted bisphenol compounds such as ethoxylated bisphenol A dimethacrylate as the photopolymerizable compound, and benzyl (also known as diphenylethanedione) or its photopolymerization initiator (photo radical polymerization initiator) When a three-dimensional object is manufactured by performing optical modeling using the resin composition for optical three-dimensional modeling of the present invention containing a photo radical polymerization initiator composed of a dialkyl acetal compound (for example, benzyldimethyl ketal), strength and heat resistance On the other hand, it is possible to obtain a three-dimensional structure that is sufficiently foamed and easily collapsed when heated to a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsule.

The thermally expandable microcapsules contained in the resin composition for optical three-dimensional modeling of the present invention are also referred to as thermally expandable microspheres, thermally expandable fine particles, and the like.
Thermally expandable microcapsules are microcapsules in which a volatile liquid expansion agent such as liquefied hydrocarbon is encapsulated in an outer shell made of a thermoplastic polymer, and the expansion of the liquid expansion agent encapsulated in the microcapsule begins. By heating to a temperature higher than the temperature, it usually expands to a volume of about 10 times to several tens of times and sometimes 100 times.

  With regard to the thermally expandable microcapsules, many applications have been filed (for example, Patent Documents 4 to 6), and various types are commercially available (for example, Kureha microspheres, Matsumoto microspheres, dyes). Form V etc.).

  In the present invention, the type of thermally expandable microcapsule to be contained in the optical three-dimensional modeling resin composition is not particularly limited, and the type of photopolymerizable compound contained in the optical three-dimensional modeling resin composition of the present invention, A suitable one can be used according to the component composition of the composition, the use of the three-dimensional structure obtained by optical modeling using the resin composition for optical three-dimensional modeling of the present invention, the usage form, and the like.

  As the thermally expandable microcapsule, the expansion start temperature (foaming start temperature) is about 90 ° C., about 100 ° C., about 125 ° C., depending on the type of liquid expansion agent contained in the outer shell, etc. Various products such as those of 140 ° C., about 180 ° C., about 190 ° C., and about 260 ° C. are already commercially available.

  The temperature of the modeling bath when performing optical three-dimensional modeling using a resin composition for optical three-dimensional modeling containing a photopolymerizable compound and a photopolymerization initiator is generally in the range of 10 to 40 ° C., and the atmospheric temperature is Since it is generally in the range of 20 to 50 ° C., any of thermally expandable microcapsules having an expansion start temperature (foam start temperature) higher than 50 ° C. can be used in the present invention. For the type of photopolymerizable compound contained in the resin composition for optical three-dimensional modeling, the component composition of the resin composition for optical three-dimensional modeling, the heat deformation temperature of the three-dimensional modeled object obtained by optical modeling, the application, the usage form, etc. Accordingly, it is preferable to select and use a thermally expandable microcapsule having an expansion start temperature suitable for each situation. In general, if the expansion start temperature of the thermally expandable microcapsule is too low, the expansion of the thermally expandable microcapsule occurs before the softening temperature (thermal deformation temperature) of the 3D object is reached. When foaming becomes difficult to perform sufficiently, on the other hand, when the expansion start temperature of the thermally expandable microcapsule is too high, the three-dimensional object is thermally deteriorated before the expansion of the thermally expandable microcapsule is started. When the product is used as a core, thermal deterioration of the polymer used for the production of the molded product is likely to occur.

  In general, a thermally expandable microcapsule having an expansion start temperature higher than 50 ° C. and not higher than 260 ° C., more preferably in the range of 70 to 210 ° C., particularly 90 to 180 ° C. is preferable because of easy temperature control. Used.

  The particle diameter of the thermally expandable microcapsule is such that the average particle diameter is 1 to 100 μm from the viewpoints of handleability when performing optical three-dimensional modeling, dimensional accuracy of the three-dimensional model to be obtained, availability, and the like. Preferably, it is 10-50 micrometers.

  If the particle size of the heat-expandable microcapsules is too small, the three-dimensional structure including the heat-expandable microcapsules will not foam sufficiently when heated above the expansion start temperature of the heat-expandable microcapsules, When the capsule particle size is too large, workability at the time of optical three-dimensional modeling decreases, the strength and heat resistance of the resulting three-dimensional model decreases, and dimensional accuracy decreases.

Here, the average particle diameter of the thermally expandable microcapsule referred to in the present specification is a value measured by a laser diffraction scattering method.
In the resin composition for optical three-dimensional model | molding of this invention, content of a thermally expansible microcapsule is a kind of photopolymerizable compound contained in a photocurable resin composition, a composition of a photocurable resin composition, and optical modeling. It can adjust according to the use of the three-dimensional molded item obtained by using, a usage form, etc. Foaming (expansion) is sufficient when the three-dimensional structure obtained by stereolithography has good strength, heat resistance and dimensional accuracy, and the three-dimensional structure is heated above the expansion start temperature of the thermally expandable microcapsule contained therein. ), The content of the thermally expandable microcapsule is 20 to 80 parts by mass with respect to 100 parts by mass of the total photopolymerizable compound contained in the optical three-dimensional modeling resin composition. It is preferably 35 to 75 parts by mass, more preferably 40 to 70 parts by mass, and still more preferably 45 to 65 parts by mass.

  The optical three-dimensional modeling resin composition of the present invention may optionally contain a polyalkylene ether compound. When a polyalkylene ether compound is contained, physical properties such as impact resistance of the resulting three-dimensional structure are improved, and when the three-dimensional structure is heated to a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsule. The three-dimensional structure is foamed well. As the polyalkylene ether compound, those having a number average molecular weight in the range of 500 to 10,000, particularly 500 to 5,000 are preferably used.

Suitable examples of the above polyalkylene ether compounds include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene oxide-polypropylene oxide block copolymer, random copolymer of ethylene oxide and propylene oxide, formula: —CH An oxytetramethylene unit (having an alkyl substituent) having an alkyl substituent represented by ₂ CH ₂ CH (R ¹ ) CH ₂ O— (wherein R ¹ is a lower alkyl group, preferably a methyl or ethyl group) Polyether represented by tetramethylene ether unit), alkyl represented by the above oxytetramethylene unit and the above formula: —CH ₂ CH ₂ CH (R ¹ ) CH ₂ O— (wherein R ¹ is a lower alkyl group) Oxytetramethyl with substituent Such polyethers down units are randomly bonded can be mentioned.

Among them, a polytetramethylene glycol and / or tetramethylene ether unit having a number average molecular weight in the range of 500 to 10,000 described above and a formula: —CH ₂ CH ₂ CH (R ¹ ) CH ₂ O— (wherein R ^A polyether in which tetramethylene ether units having an alkyl substituent represented by ¹ is a lower alkyl group is preferably used. In that case, the hygroscopic property is low, and the dimensional stability and physical property stability are improved. It is possible to obtain a three-dimensional structure that is excellent and has excellent foamability.

  The content of the polyalkylene ether compound in the resin composition for optical three-dimensional modeling of the present invention is preferably 0 to 30% by mass with respect to the total mass of the resin composition for optical three-dimensional modeling, and 2 to 20 More preferably, it is mass%. Moreover, you may contain the 2 or more types of polyalkylene ether type compound simultaneously in the range which does not exceed the said content.

  If the optical curing of the resin composition for optical three-dimensional modeling is slow, optical modeling may become difficult, or the strength of the three-dimensional molded product obtained may be insufficient, and the toughness and rigidity of the three-dimensional molded product obtained are too high. And when the three-dimensional model obtained by stereolithography is heated to a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsule, foaming of the three-dimensional model is difficult to occur, so the strength is not insufficient before heating and foaming. The type of photopolymerizable compound constituting the resin composition for optical three-dimensional modeling, the type of photopolymerization catalyst, and the resin composition for optical three-dimensional modeling so as to obtain a three-dimensional modeled product that foams sufficiently when heated It is preferable to select the component composition, etc., and adjust the type, thermal expansion performance, content, and the like of the thermally expandable microcapsules.

  The resin composition for optical three-dimensional model | molding of this invention is as needed as long as the effect of this invention is not impaired with a photopolymerizable compound, a photoinitiator, a thermally expansible microcapsule, and the polyalkylene ether type compound depending on the case. Colorants such as pigments and dyes, antifoaming agents, leveling agents, thickeners, flame retardants, antioxidants, fillers (crosslinked polymer particles, silica, glass powder, ceramic powder, metal powder, etc.), modification An appropriate amount of at least one kind of resin may be contained.

  Any of the conventionally known optical three-dimensional modeling methods and apparatuses can be used for optical three-dimensional modeling using the resin composition for optical three-dimensional modeling of the present invention. As a representative example of the optical three-dimensional modeling method that can be preferably adopted, the active energy ray is selectively irradiated so that a cured layer having a desired pattern can be obtained in the liquid resin composition for optical three-dimensional modeling of the present invention. Then, a hardened layer is formed, and then an uncured liquid resin composition for optical three-dimensional modeling is supplied to the hardened layer. Similarly, the hardened layer continuous with the hardened layer is newly irradiated with active energy rays. The method of finally obtaining the target three-dimensional model | molding can be mentioned by repeating the lamination | stacking operation formed in this.

  Examples of the active energy rays at that time include ultraviolet rays, electron beams, X-rays, radiation, and high frequencies as described above. Among them, ultraviolet rays having a wavelength of 300 to 400 nm are preferably used from an economical viewpoint, and as a light source at that time, an ultraviolet laser (for example, a semiconductor-excited solid laser, an Ar laser, a He—Cd laser), a high-pressure mercury lamp is used. Ultra high pressure mercury lamps, low pressure mercury lamps, xenon lamps, halogen lamps, metal halide lamps, ultraviolet LEDs (light emitting diodes), ultraviolet fluorescent lamps, and the like can be used.

  When forming a cured resin layer having a predetermined shape pattern by irradiating an active energy ray on a modeling surface made of a resin composition for optical three-dimensional modeling, the active energy is reduced to a point such as a laser beam. A planar drawing mask in which a hardened resin layer may be formed by a line drawing method using a line or a plurality of micro light shutters such as a liquid crystal shutter or a digital micromirror shutter (DMD). Alternatively, a modeling method may be employed in which a cured resin layer is formed by irradiating the modeling surface with active energy rays through the surface.

  In performing optical modeling using the resin composition for optical three-dimensional modeling of the present invention containing the heat-expandable microcapsules, the heat-expandable microcapsules float and separate above the resin composition for optical three-dimensional modeling. If it is in the state, it becomes difficult to perform optical modeling smoothly, and it becomes difficult to obtain a three-dimensional modeled product in which thermally expandable microcapsules are uniformly dispersed, so the optical three-dimensional modeled resin composition is stirred. However, it is preferable to perform stereolithography. In addition, by adjusting the viscosity of the resin composition for optical three-dimensional modeling and adding anti-floating agents such as thickeners, floating separation of thermally expandable microcapsules in the resin composition for optical three-dimensional modeling Can be suppressed.

  The optical three-dimensional structure obtained by optical modeling using the resin composition for optical three-dimensional modeling of the present invention contains a thermally expandable microcapsule in an unexpanded state, and the expansion of the thermally expandable microcapsule. By heating above the start temperature and above the softening temperature of the three-dimensional modeled object, above the heat deformation temperature or above the heat melting temperature, it foams and collapses, or foams and greatly reduces its strength.

  From this point, the three-dimensional structure obtained by optical modeling using the resin composition for optical three-dimensional modeling of the present invention is a core (disappearing core) to be removed after use, a master model for casting, etc. It can be effectively used for

  Although it is not limited at all, by using the core (three-dimensional modeled object) obtained by performing optical modeling using the resin composition for optical three-dimensional model | molding of this invention containing a thermally expansible microcapsule. For example, as described below with reference to FIG. 1, the hollow molded body can be manufactured smoothly.

  First, using the resin composition for optical three-dimensional modeling of the present invention containing a thermally expandable microcapsule, for example, the thermally expandable microcapsule 2 in an unexpanded state as shown in FIG. The core 1 to be manufactured is manufactured.

  Next, as shown in FIG. 1 (b), the core 1 is disposed in the outer mold 3 with a molding space 4 disposed therein, and then, as shown in FIG. A polymerizable material that forms a coalescence or elastic polymer is introduced to form the elastic polymer layer 5 on the surface of the core 1.

  Next, as shown in FIG. 1 (d), after the core 1 having the elastic polymer layer 5 formed on the surface thereof is taken out from the outer mold 3, the thermally expandable microcapsule contained in the core 1 is removed. By expanding the thermally expandable microcapsule 2 by heating to a temperature equal to or higher than the expansion start temperature, the core 1 is foamed and collapsed as shown in FIG. 6 or a foam 6 that easily disintegrates in strips.

  Finally, the foamed / collapsed material 6 derived from the core is taken out of the hollow molded body made of an elastic polymer. The hollow molded body 7 made of a soft elastic polymer shown in FIG. 1 (f) can be obtained.

  In FIG. 1, since the hollow molded body 7 is formed of an elastic polymer, the core 1 having the elastic polymer layer 5 formed on the surface is taken out from the outer mold 3, and then heat treatment is performed. Even if foaming / collapse is performed, the hollow molded body 7 made of an elastic polymer that swells during foaming can return to its original size due to its elasticity when the foam / collapse material derived from the core is removed.

  Depending on the physical properties (heat resistance, softening point, presence / absence of elasticity, strength, etc.) of the material for hollow molded body production, heating and foaming of the core on which the surface of the hollow molded body production material layer is formed will depend on the outer mold It may be carried out after being taken out from the container or may be carried out while being put in the outer mold.

In FIG. 1, the shape of the core is hollow, but the shape is not limited thereto, and may be a solid core.
The core obtained by using the resin composition for optical three-dimensional modeling of the present invention containing the heat-expandable microcapsule is used for producing a hollow molded body by increasing the wall thickness even when making a hollow shape. The strength can sufficiently withstand the molding operation and pressure. Even if the wall thickness of the hollow core is increased, or the core is solid, the foam collapsed into strips by heating to a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsule. Or a foam that can be easily disintegrated into strips and can be easily discharged from the hollow molded body.

  In FIG. 1, although illustrated about the case where a hollow molded object is manufactured using the core manufactured by performing optical three-dimensional modeling using the resin composition for optical three-dimensional modeling of this invention, it is limited to it. It is not a thing, it performs optical three-dimensional modeling using the resin composition for optical three-dimensional modeling of the present invention to produce a hollow molded body for a master model, and various types using a master model composed of the hollow molded body. Molded bodies and products can be manufactured.

  In that case, a molding material (for example, silicone or other organic polymer, curable inorganic material, etc.) inside the hollow master model (hollow molded body) formed from the resin composition for optical three-dimensional modeling of the present invention. ) To fill the entire interior space of the master model with the molding material or to solidify or cure the molding material with the molding material layer formed on the inner wall of the master model, By heating above the expansion start temperature of the thermally expandable microcapsule contained in the master model to foam and collapse the outer master model, the molded body formed inside the master model can be taken out.

By this method, it is possible to produce a hollow molded body that can be used for molds and other applications, and a solid molded body that can be used for various applications.
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples.

  Moreover, in the following examples, the viscosity of the resin composition for optical modeling, the measurement of the mechanical properties (bending strength, bending elastic modulus) and the thermal deformation temperature of the three-dimensional modeled object obtained by optical modeling, and the optical modeling Evaluation of foamability of the obtained three-dimensional molded item was performed as follows.

(1) Viscosity of the resin composition for optical three-dimensional modeling:
After the resin composition for optical three-dimensional modeling is put in a thermostatic bath at 25 ° C. and the temperature of the resin composition for optical three-dimensional modeling is adjusted to 25 ° C., a B-type viscometer (manufactured by Toki Sangyo Co., Ltd.) is used. And measured at a rotational speed of 20 rpm.

(2) Flexural strength and flexural modulus of the three-dimensional structure:
The bending strength and the flexural modulus of the test piece were measured according to JIS K-7171 using an optically shaped article (bar-shaped test piece conforming to JIS K-7171) produced in the following examples.

(3) Thermal deformation temperature of the three-dimensional structure:
Using a three-dimensional modeled object (bar-shaped test piece conforming to JIS K-7171) produced in the following examples and the like, a “HDT tester 6M-2” manufactured by Toyo Seiki Co., Ltd. was used. A 45 MPa load was applied, and the thermal deformation temperature of the test piece was measured in accordance with JIS K-7207 (Method B).

(4) Foamability of the three-dimensional structure:
Foamed state when a three-dimensional model (bar-shaped test piece based on JIS K-7171) similar to the above (3) prepared in the following examples is heated in a thermostatic bath at 150 ° C. for 10 minutes Evaluated.

Example 1
(1) 100 parts by mass of ethoxylated bisphenol A dimethacrylate (“BPE-200” manufactured by Shin-Nakamura Chemical Co., Ltd.), 15 parts by mass of polytetramethylene glycol (“PTG-850SN” manufactured by Hodogaya Chemical Co., Ltd.), benzyldimethyl ketal 2.5 parts by mass (“Irgacure 651” manufactured by BASF) and 58 parts by mass of Kureha Microsphere “H850” (expansion start temperature 125 ° C., average particle size 35 μm) are mixed well at room temperature (25 ° C.) to obtain an optical A resin composition for three-dimensional modeling was manufactured. It was 4,500 mPa * s (25 degreeC) when the viscosity of this resin composition for optical three-dimensional modeling was measured by the above-mentioned method.

(2) Using the resin composition for optical three-dimensional modeling obtained in (1) above, a semiconductor laser (rated output 1000 mW; wavelength) using an ultra-high-speed optical modeling system (“SOLIFORM 500B” manufactured by Nabtesco Corporation) 355 nm; Spectra Physics “Semiconductor-excited solid laser BL6 type”), with a liquid surface of 100 mW and a liquid surface irradiation energy of 80 mJ / cm ² , a slice pitch (lamination thickness) of 0.10 mm and average modeling per layer After performing optical modeling in 2 minutes, a bar-shaped test piece according to JIS K-7171 for measuring physical properties and evaluating foamability was prepared, and the obtained test piece was heated at 80 ° C. for 2 hours. Cured.

  (3) When the bending strength, bending elastic modulus and thermal deformation temperature (Method B) of the post-cured test piece obtained in (2) above were measured by the methods described above, the bending strength was 20 MPa and the bending elastic modulus was 908 MPa. The heat distortion temperature (Method B) was 73.1 ° C.

  (4) When the post-cured test piece obtained in (2) above is placed in a thermostatic bath at 150 ° C. and heated for 10 minutes, it is foamed to about 30 times the volume of the three-dimensional object before heating, As in Example 1, the bar shape was completely lost, and when the produced foam was pressed by hand, it easily collapsed into strips.

The photograph which image | photographed the foaming state when putting the post-cured bar-shaped test piece into a 150 degreeC thermostat and heating for 10 minutes is shown in FIG.
Example 2
(1) 100 parts by mass of ethoxylated bisphenol A dimethacrylate (“BPE-200” manufactured by Shin-Nakamura Chemical Co., Ltd.), 2.5 parts by mass of benzyldimethyl ketal (“Irgacure 651” manufactured by BASF) and Kureha Microsphere “H850” 58 parts by mass (expansion start temperature 125 ° C., average particle size 35 μm) were mixed well at room temperature (25 ° C.) to produce a resin composition for optical three-dimensional modeling. It was 5,700 mPa * s (25 degreeC) when the viscosity of this resin composition for optical three-dimensional modeling was measured by the above-mentioned method.

  (2) Using the resin composition for optical three-dimensional modeling obtained in (1) above, optical modeling is performed in the same manner as in (2) of Example 1 for measuring physical properties and for evaluating foamability. A bar-shaped test piece according to JIS K-7171 was prepared, and the obtained test piece was post-cured by heating at 80 ° C. for 2 hours.

  (3) When the bending strength, bending elastic modulus, and thermal deformation temperature (Method B) of the post-cured test piece obtained in (2) above were measured by the methods described above, the bending strength was 30 MPa and the bending elastic modulus was 1764 MPa. The heat distortion temperature (Method B) was 86.6 ° C.

  (4) When the post-cured test piece obtained in (2) above is placed in a thermostatic bath at 150 ° C. and heated for 10 minutes, it is foamed to about 10 times the volume of the three-dimensional object before heating, The bar shape was lost while leaving the outer skin a little, and when the foam produced was pressed by hand, it almost collapsed into strips.

The photograph which image | photographed the foaming state when putting the post-cured bar-shaped test piece into a 150 degreeC thermostat and heating for 10 minutes is shown in FIG.
Example 3
(1) 100 parts by mass of ethoxylated bisphenol A dimethacrylate (“BPE-200” manufactured by Shin-Nakamura Chemical Co., Ltd.), 15 parts by mass of polytetramethylene glycol (“PTG-850SN” manufactured by Hodogaya Chemical Co., Ltd.), benzyldimethyl ketal 2.5 parts by mass (“Irgacure 651” manufactured by BASF) and 39 parts by mass of Kureha Microsphere “H850” (expansion start temperature 125 ° C., average particle size 35 μm) are mixed well at room temperature (25 ° C.), and optical A resin composition for three-dimensional modeling was manufactured. It was 1,870 mPa * s (25 degreeC) when the viscosity of this resin composition for optical three-dimensional modeling was measured by the above-mentioned method.

  (2) Using the resin composition for optical three-dimensional modeling obtained in (1) above, optical modeling is performed in the same manner as in (2) of Example 1 for measuring physical properties and for evaluating foamability. A bar-shaped test piece according to JIS K-7171 was prepared, and the obtained test piece was post-cured by heating at 80 ° C. for 2 hours.

  (3) When the bending strength, bending elastic modulus and thermal deformation temperature (method B) of the post-cured test piece obtained in (2) above were measured by the methods described above, the bending strength was 26 MPa and the bending elastic modulus was 1024 MPa. The heat distortion temperature (Method B) was 63.2 ° C.

  (4) When the post-cured test piece obtained in (2) above is placed in a thermostatic bath at 150 ° C. and heated for 10 minutes, it is foamed to about 20 times the volume of the three-dimensional object before heating, The bar shape was lost while leaving a little skin, and when the foam produced was pressed by hand, it collapsed into strips easily.

<< Reference Example 1 >>
(1) 100 parts by mass of ethoxylated bisphenol A dimethacrylate (“BPE-200” manufactured by Shin-Nakamura Chemical Co., Ltd.), 2,4,6-trimethylbenzoyl-diphenynylphosphine oxide (“LUCIRIN TPO” manufactured by BASF) ”) 2.5 parts by mass and Kureha Microsphere“ H850 ”(expansion start temperature 125 ° C., average particle size 35 μm) 58 parts by mass are mixed well at room temperature (25 ° C.) to obtain a resin composition for optical three-dimensional modeling. Manufactured. It was 8,600 mPa * s (25 degreeC) when the viscosity of this resin composition for optical three-dimensional modeling was measured by the above-mentioned method.

  (2) Using the resin composition for optical three-dimensional modeling obtained in (1) above, optical modeling is performed in the same manner as in (2) of Example 1 for measuring physical properties and for evaluating foamability. A bar-shaped test piece according to JIS K-7171 was prepared, and the obtained test piece was post-cured by heating at 80 ° C. for 2 hours.

  (3) When the bending strength, bending elastic modulus and thermal deformation temperature (Method B) of the post-cured test piece obtained in (2) above were measured by the methods described above, the bending strength was 26 MPa and the bending elastic modulus was 1438 MPa. The heat distortion temperature (Method B) was 95.4 ° C.

  (4) When the post-cured test piece obtained in (2) above was placed in a thermostatic bath at 150 ° C. and heated for 10 minutes, it foamed to about 5 times the volume of the three-dimensional object before heating. The outer skin was left, and when the foam produced was pressed by hand, it did not collapse completely and a lump remained. Since the thermal deformation temperature of the cured product is about 9 ° C. higher than that in Example 1, it is presumed that the foaming property has decreased.

The photograph which image | photographed the foaming state when putting the post-cured bar-shaped test piece into a 150 degreeC thermostat and heating for 10 minutes is shown in FIG.
<< Comparative Example 1 >>
(1) 100 parts by mass of ethoxylated bisphenol A dimethacrylate (“BPE-200” manufactured by Shin-Nakamura Chemical Co., Ltd.), 15 parts by mass of polytetramethylene glycol (“PTG-850SN” manufactured by Hodogaya Chemical Co., Ltd.), benzyldimethyl ketal (BASF "Irgacure 651") 2.5 parts by mass and organic chemical foaming agent [Sankyo KK "Cermic SX" (p, p'-oxybisbenzenesulfonylhydrazide, decomposition temperature 155 to 180 ° C)] 39 mass parts was mixed well at room temperature (25 degreeC), and the resin composition for optical three-dimensional modeling was manufactured. It was 1450 mPa * s (25 degreeC) when the viscosity of this resin composition for optical three-dimensional modeling was measured by the above-mentioned method.

  (2) Using the resin composition for optical three-dimensional modeling obtained in (1) above, optical modeling is performed in the same manner as in (2) of Example 1 for measuring physical properties and for evaluating foamability. A bar-shaped test piece according to JIS K-7171 was prepared, and the obtained test piece was post-cured by heating at 80 ° C. for 2 hours. Note that foaming did not occur during stereolithography and post-curing.

(3) The post-cured test piece obtained in (2) above was placed in a thermostatic bath at 180 ° C. and heated for 15 minutes, but no foaming occurred.
<< Comparative Example 2 >>
(1) 100 parts by mass of ethoxylated bisphenol A dimethacrylate (“BPE-200” manufactured by Shin-Nakamura Chemical Co., Ltd.), 15 parts by mass of polytetramethylene glycol (“PTG-850SN” manufactured by Hodogaya Chemical Co., Ltd.), benzyldimethyl ketal (BASF “Irgacure 651”) 2.5 parts by mass and inorganic chemical foaming agent [Sankyo Co., Ltd. “Cermic 266” (sodium bicarbonate, decomposition temperature 140 to 170 ° C.)] 13 parts by mass at room temperature ( The resin composition for optical three-dimensional modeling was manufactured by mixing well at 25 ° C. It was 950 mPa * s (25 degreeC) when the viscosity of this resin composition for optical three-dimensional modeling was measured by the above-mentioned method. (In addition, when the cell microphone 266 was mixed at a ratio of 39 parts by mass in the same manner as in Comparative Example 1, a uniform resin composition for optical three-dimensional modeling was not obtained. In Comparative Example 2, the cell microphone 266 was described above. (Mixed in an amount of 13 parts by mass.)
(2) Using the resin composition for optical three-dimensional modeling obtained in (1) above, optical modeling is performed in the same manner as in (2) of Example 1 for measuring physical properties and for evaluating foamability. A bar-shaped test piece according to JIS K-7171 was prepared, and the obtained test piece was post-cured by heating at 80 ° C. for 2 hours. Note that foaming did not occur during stereolithography and post-curing.

  (3) The post-cured test piece obtained in (2) above was placed in a thermostatic bath at 180 ° C. and heated for 15 minutes, but no foaming occurred.

  The three-dimensional structure obtained by optical modeling using the resin composition for optical three-dimensional modeling of the present invention containing the thermally expandable microcapsule has sufficient strength that can be practically used before foaming by heating. On the other hand, when heated above the expansion start temperature of the thermally expandable microcapsule, it foams greatly and becomes a foam that can be collapsed into strips or easily collapsed into strips. Therefore, it is useful as a core or a casting master model when manufacturing a hollow molded body.

DESCRIPTION OF SYMBOLS 1 Core 2 Thermally expansible microcapsule 3 Outer mold | type 4 Molding space 5 Polymer or polymeric material 6 Foam collapsed into strip shape 7 Hollow molded body

Claims (8)

A resin composition for optical three-dimensional modeling containing a photopolymerizable compound, a photopolymerization initiator, and a thermally expandable microcapsule ;
The thermal expansion start temperature of the thermally expandable microcapsule is in the range of 90-260 ° C; and
Content of the said thermally expansible microcapsule is 20-80 mass parts with respect to 100 mass parts of all the photopolymerizable compounds contained in the resin composition for optical three-dimensional modeling;
A resin composition for optical three-dimensional modeling characterized by the above . Thermally expandable microcapsule comprises a shell made of a thermoplastic polymer, and is encapsulated in the outer shell volatile liquid expanding agent, having an average particle size of 1 to 100 [mu] m, according to claim 1 A resin composition for optical three-dimensional modeling. The resin composition for optical three-dimensional modeling according to claim 1 or 2 , wherein the photopolymerizable compound is selected from one or more radical polymerizable compounds, one or more cationic polymerizable compounds, or both. The resin composition for optical three-dimensional modeling according to any one of claims 1 to 3 , wherein the photopolymerizable compound is a radical polymerizable compound and the photopolymerization initiator is a photoradical polymerization initiator. The resin composition for optical three-dimensional modeling according to claim 3 or 4 , wherein the radical polymerizable compound is a di (meth) acrylate compound having two (meth) acryloyloxy groups. The resin composition for optical three-dimensional modeling according to claim 5 , wherein the di (meth) acrylate compound having two (meth) acryloyloxy groups is a di (meth) acrylate of a substituted or unsubstituted bisphenol. object. The resin composition for optical three-dimensional modeling according to any one of claims 4 to 6 , wherein the radical photopolymerization initiator is benzyl or a dialkyl acetal compound thereof. The resin composition for optical three-dimensional model | molding of any one of Claims 1-7 which further contains a polyalkylene ether type compound.