WO2013151159A1 - Core containing thermally expandable microcapsule - Google Patents

Abstract

A core contains a thermally expandable microcapsule. A layer composed of a material for hollow molded article production purposes is formed on the surface of the core. The core is expanded and collapsed by heating the core to a temperature that is equal to or higher than a temperature at which the expansion of the thermally expandable microcapsule contained in the core starts. An expansion/collapse product derived from the core is discharged from the inside of a hollow molded article that is formed from the material for hollow molded article production purposes toward the outside of the hollow molded article.

Description

Core containing thermally expandable microcapsules

The present invention relates to a core containing a thermally expandable microcapsule and a method for producing a hollow molded body using the core.

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 manufactured 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, it is possible to manufacture a core having a complicated shape. 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 hollow flexible 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 excellent in strength, shape retention and handling, and when used as a core, does not cause breakage or deformation, and can sufficiently function as a core. It is an object of the present invention to provide a core that can be easily removed from a hollow molded body or a mold that has been manufactured after use.

Another object of the present invention is to provide a core that can be easily manufactured even if it has a complicated shape or structure, and can be easily manufactured even if it is a minute size. It is.

Furthermore, an object of the present invention is to provide a hollow molded body, a mold and a method for producing various molded bodies using the core.

The present inventors have made various studies to achieve the above-mentioned purpose. As a result, when the core is formed from a material containing thermally expandable microcapsules and heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsules, the entire core is foamed and collapsed. I found it easy to remove.

Furthermore, the present inventors produce the core by performing optical three-dimensional modeling using a resin composition for optical three-dimensional modeling containing a photopolymerizable compound, a photopolymerization initiator, and a thermally expandable microcapsule. Then, it has been found that even a core having a complicated structure or shape or a core having a small size can be easily and smoothly manufactured with high dimensional accuracy as intended.

In addition, the present inventors have used a core manufactured by performing optical three-dimensional modeling using a resin composition for optical three-dimensional modeling containing thermally expandable microcapsules, for example, an artificial heart or the like. The present inventors have found that a hollow molded article having a simple structure, a mold, and various molded articles can be produced smoothly, and based on these findings, the present invention has been completed.

That is, the present invention
(1) A core that contains thermally expandable microcapsules and foams and collapses when heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsules.

The present invention also provides:
(2) It is manufactured by performing optical three-dimensional modeling using a resin composition for optical three-dimensional modeling containing a photopolymerizable compound, a photopolymerization initiator, and a thermally expandable microcapsule, 1) the core;
(3) 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 ( 1) or (2) the core; and
(4) 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 resin composition for optical three-dimensional modeling used for the production of the core. The core of (2) or (3);
It is.

The present invention also provides:
(5) The photopolymerizable compound in the resin composition for optical three-dimensional modeling used for the production of the core is selected from one or more radically polymerizable compounds, one or more cationically polymerizable compounds, or both The core of any one of (2) to (4);
(6) The core of the above (5), wherein the photopolymerizable compound is a radical polymerizable compound, and the photopolymerization initiator is a photoradical polymerization initiator;
(7) The core of (5) or (6) above, wherein the radical polymerizable compound is a di (meth) acrylate compound having two (meth) acryloyloxy groups;
(8) The core of (7) above, wherein the di (meth) acrylate compound having two (meth) acryloyloxy groups is a di (meth) acrylate of a substituted or unsubstituted bisphenol;
(9) The core of any one of (6) to (8), wherein the radical photopolymerization initiator is benzyl or a dialkyl acetal compound thereof; and
(10) The core according to any one of the above (2) to (9), wherein the resin composition for optical three-dimensional modeling used for the production of the core further contains a polyalkylene ether compound;
(11) The core according to any one of (1) to (10), which is a core for use in the production of a hollow molded body made of an organic polymer;
It is.

Furthermore, the present invention provides
(12) (a) a step of forming a layer of a material for producing a hollow molded body on the surface of the core of any one of (1) to (11);
(B) a step in which a core having a layer of a material for producing a hollow molded body formed on the surface is heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule contained in the core and foamed to be collapsed; and
(C) a step of discharging the foamed / collapsed material derived from the core from the inside of the hollow molded body formed from the material for manufacturing the hollow molded body;
It is a manufacturing method of the hollow molded object which has this.

Furthermore, the present invention provides:
(13) The step (a) of forming a layer of the material for manufacturing a hollow molded body on the surface of the core is formed between the surface of the core and the inner surface of the outer mold by arranging the core in the outer mold. Filling the voids with the material for producing a hollow molded body, and the heating and foaming in the step (b) are performed with the core placed in the outer mold or the surface of the material for producing the hollow molded body on the surface. (12) The method for producing a hollow molded body according to the above (12), wherein the core is formed by taking out the core from the outer mold;
(14) The production method of the above (12) or (13), wherein the material for producing a hollow molded body is an organic polymer material or an organic polymerizable material; and
(15) The method for producing a hollow molded article according to (13) or (14), wherein the outer mold is produced by optical three-dimensional modeling using a resin composition for optical three-dimensional modeling;
It is.

Furthermore, the present invention provides
(16) (α) forming a layer of a mold forming material on the surface of the core according to any one of claims 1 to 11;
(Β) a step in which a core having a layer made of a mold-forming material formed on the surface is heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule contained in the core and foamed to be collapsed; and
(Γ) discharging the foam / collapsed material derived from the core from the inside of the mold formed from the mold forming material;
A method of manufacturing a mold having:
(17) A method for producing a molded body, in which the mold obtained in (16) is filled with a fluid molding material and cured or solidified, and then the mold is separated;
It is.

The core of the present invention is excellent in strength, shape retention and handleability, and smoothly produces the desired hollow molded body or mold without being damaged or deformed when used as a core. After the use as a core is completed, the core is obtained by expanding the thermally expandable microcapsule by heating to a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsule contained in the core. Since the whole foams and collapses, the collapsed foam derived from the core can be easily removed from the manufactured hollow molded body or mold.

When the core of the present invention is a core obtained by performing optical three-dimensional modeling using a resin composition for optical three-dimensional modeling containing thermally expandable microcapsules, the core has a complicated shape or structure Even if it is, even if it is a micro size, it can be manufactured easily.

By manufacturing a hollow molded body by the method of the present invention using the core of the present invention, a hollow molded body having a complicated shape or structure or a hollow molded body having a small size can be manufactured smoothly.

In addition, a mold is manufactured using the core of the present invention, and the mold is filled with a material for manufacturing a molded body and cured or solidified to form a molded body having a complicated shape or structure (solid molded body and Hollow molded bodies) and small molded bodies (solid molded bodies and hollow molded bodies) can be produced smoothly.

FIG. 1 is a diagram showing an example of manufacturing a hollow molded body using the core of the present invention containing thermally expandable microcapsules. FIG. 2 is a drawing-substituting photograph showing a foamed state when the optical three-dimensional object (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 core of the present invention is a core that contains a thermally expandable microcapsule and foams and collapses when heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule.

Here, “the core expands and collapses” in the present specification means that the core expands as the thermally expandable microcapsule contained in the core expands, and the pieces are directly separated into pieces. It becomes a foam, or it becomes a foam without shape retention that easily collapses into small pieces with a small external force, or it has no shape retention and the volume is reduced with a small external force so that it can be easily removed from the opening of the hollow molded body. It means that it becomes ready to be taken out.

The core of the present invention is used when producing a hollow molded body using an organic polymer material or other materials, and further used for forming a mold, and the hollow core is formed on the surface of the core of the present invention. After forming the body manufacturing material layer or the mold forming material layer, the core formed on the inner surface of the hollow molded body or the mold is heated together with the layers formed on the surface of the core. The thermally expandable microcapsules contained therein are expanded, whereby the entire core is foamed and collapsed, and the collapsed core is discharged from the inside of the hollow molded body or mold to the outside.

The thermally expandable microcapsules contained in the core 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 to several tens of times, and sometimes 100 times.

With respect to the thermally expandable microcapsules, many applications have been filed (for example, Patent Documents 4 to 6), and various thermally expandable microcapsules are already on the market (for example, Kureha Microsphere, Matsumoto Micro, etc.). Sphere, Die Form V, etc.).

Commercially available thermally expandable microcapsules include those having various expansion start temperatures depending on the type of liquid expander encapsulated in the outer shell, for example, those having an expansion start temperature (foaming start temperature) of about 90 ° C., About 100 ° C, about 125 ° C, about 140 ° C, about 180 ° C, about 190 ° C, about 260 ° C are sold.

The type of the heat-expandable microcapsule to be contained in the core of the present invention is not particularly limited, and the type of material such as resin forming the core, the hollow molded body or the mold is manufactured using the core of the present invention. Depending on the type of material used to manufacture the hollow molded body and mold, the temperature conditions at the time of manufacturing the hollow molded body and mold, the shape, structure, size, etc. of the hollow molded body intended for production, It is preferable to select the type of thermally expandable microcapsule to be contained.

In general, if the expansion start temperature of the thermally expandable microcapsule is too low, the thermally expandable microcapsule expands before reaching the softening temperature or melting temperature of the material constituting the core. Therefore, when the used core is heated to foam and collapse (hereinafter referred to as “foaming and collapsing” is referred to as “foaming and collapsing”), the core is foamed and collapsed. Will not be performed. On the other hand, if the expansion start temperature of the thermally expandable microcapsule is too high, when the used core is heated and foamed / collapsed, before the expansion of the thermally expandable microcapsule starts, the surface of the core Softening, melting, thermal degradation, etc. of the layer for forming a hollow molded body (material used for forming the hollow molded body) and the mold forming material layer formed in The mold cannot be obtained, and the quality of the obtained hollow molded body or mold is deteriorated.

The particle size of the thermally expandable microcapsule contained in the core is determined by the handling properties when the core is manufactured by an optical three-dimensional modeling method, the dimensional accuracy of the obtained core, the expansion characteristics of the thermally expandable microcapsule, the heat In view of the availability of expandable microcapsules, the average particle size is preferably 1 to 100 μm, more preferably 10 to 50 μm.

If the particle size of the thermally expandable microcapsule is too small, when the core containing the used thermally expandable microcapsule is heated above the expansion start temperature of the thermally expandable microcapsule to foam / collapse, If the particle size of the thermally expandable microcapsule is too large, the workability when the core is manufactured by an optical three-dimensional modeling method, etc., and the strength of the core is obtained. And heat resistance, dimensional accuracy, etc. are likely to occur.

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.
The content of the thermally expandable microcapsule in the core of the present invention is the type of the material forming the core, the type of the hollow molded body or mold material manufactured using the core, and the core It can be adjusted according to the shape, structure, size, etc. of the hollow molded body or mold to be made.

In order to improve the strength and dimensional accuracy of the core, and to make the core sufficiently foam and easily collapse into strips when heated above the expansion start temperature of the thermally expandable microcapsule contained in the core Based on the mass of the core, the content of the thermally expandable microcapsule is preferably 15 to 65% by mass, more preferably 20 to 60% by mass, and 25 to 60% by mass. More preferred is 32 to 55% by mass.

Kinds of materials other than the thermally expandable microcapsule constituting the core manufacturing method and the core of the present invention are not particularly limited, and the material constituting the hollow molded body or mold manufactured using the core of the present invention, A suitable material can be selected according to the shape, structure, size, etc. of the hollow molded body or mold.

Among them, the core of the present invention is formed using an organic polymer material containing thermally expandable microcapsules or an organic polymerizable material containing thermally expandable microcapsules. It is preferable from the viewpoints of easiness, foamability and disintegration properties when the used core is heated to foam and collapse. As the organic polymer material or organic polymerizable material in that case, the used core is heated to expand the heat-expandable microcapsules contained in the core, thereby foaming the entire core. Softened at the temperature at which the spent core is heated, in order to make it into a foam that can collapse into pieces, can be easily collapsed or can be greatly reduced in volume when compressed An organic polymer material that melts or an organic polymerizable material that forms such an organic polymer material by polymerization may be used.

If the core is formed from a material that does not soften or melt at the temperature at which the used core is heated, even if the used core is heated, the core is less likely to foam and collapse. Become.
In view of this, a resin for optical three-dimensional modeling containing a heat-expandable microcapsule that forms a photocured product that softens or melts when the core of the present invention is heated to a temperature higher than the expansion start temperature of the heat-expandable microcapsule. When the composition is used to produce the core by an optical three-dimensional modeling method, even a core having a complicated shape or structure or a core having a small size can be manufactured smoothly and easily.

As the resin composition for optical three-dimensional modeling at that time, a resin composition containing a photopolymerizable compound, a photopolymerization initiator, and a thermally expandable microcapsule can be used. As the photopolymerizable compound, an optical three-dimensional model can be used. One or more radical polymerizable compounds, one or more cationic polymerizable compounds, or both conventionally used in modeling resin compositions can be used.

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, 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 (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 Examples include tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and (meth) acrylates of alkylene oxide adducts of polyhydric alcohols 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.

In addition, 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. The hydroxyl group-containing (meth) acrylic acid ester is preferably a hydroxyl group-containing (meth) acrylic acid ester obtained by an esterification reaction of an aliphatic dihydric alcohol and (meth) acrylic acid. 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 and 2,3-dimethyltetrahydrofuran, cyclic ethers or cyclic acetal compounds such as trioxane, 1,3-dioxolane and 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) Thietane 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. % Or more, especially 50% by mass or more of an epoxy compound (a mixture of epoxy compounds), cationic polymerization rate, thick film curability, resolution, and active energy ray permeability when a core is produced by optical three-dimensional modeling Etc., and the viscosity of the resin composition for optical three-dimensional modeling becomes low, so that the core can be manufactured smoothly by optical three-dimensional modeling, and the volume shrinkage of the core 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 And di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, and the like. 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 or 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 at that time, 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- Methyl oxetane, 3-hydroxymethyl-3-ethyl oxetane, 3-hydroxymethyl-3-propyl oxetane, 3-hydroxymethyl-3-normal butyl oxetane, 3-hydroxymethyl-3-phenyl oxetane, 3-hydroxymethyl-3 -Benzyloxetane, 3-hydroxyethyl-3-methyloxetane, 3-hydroxyethyl-3-ethyloxetane, 3-hydroxyethyl-3-propyloxetane, 3-hydroxyethyl-3-phenyloxetane, 3-hydroxypropyl-3 -Methyl oxy And 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 used for manufacture of a core may also contain the oxetane compound which has two or more 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 core obtained by optical three-dimensional modeling 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 used for manufacturing a core 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 for producing a core include benzyl or its dialkyl acetal compound, acetophenone compound, benzoin or its alkyl ether compound, benzophenone And thioxanthone compounds.

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 acetophenone compounds include diethoxyacetophenone, 2-hydroxymethyl-1-phenylpropan-1-one, 4′-isopropyl-2-hydroxy-2-methyl-propiophenone, 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 compound 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 used for manufacturing the core 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.

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

The amount of the photo radical polymerization 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.
The amount of the photocationic polymerization initiator used is preferably 0.5 to 10% by mass, particularly 1 to 5% by mass, based on the mass of the cationically polymerizable compound.

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, a core that sufficiently foams (expands) and easily collapses when heated to a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsules can be obtained.

The resin composition for optical three-dimensional model | molding which can use manufacture of the core of this invention for manufacture can contain a polyalkylene ether type compound depending on the case, and is obtained when it contains a polyalkylene ether type compound. The physical properties such as impact resistance of the three-dimensional structure are improved, and the three-dimensional structure is foamed well when the three-dimensional structure is heated to a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsule. 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.

Preferable 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 ₂ CH ₂ CH (R ¹ ) CH ₂ O— (wherein R ¹ is a lower alkyl group, preferably a methyl or ethyl group) and an oxytetramethylene unit having an alkyl substituent (having an alkyl substituent) A polyether bonded with a tetramethylene ether unit), an alkyl represented by the oxytetramethylene unit and the 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. A core excellent in foamability can be obtained.

The content of the polyalkylene ether compound in the resin composition for optical three-dimensional modeling that can be used for manufacturing the core of the present invention is 0 to 30% by mass with respect to the total mass of the resin composition for optical three-dimensional modeling. It is preferably 2 to 20% by 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.

When the optical curing of the resin composition for optical three-dimensional modeling is slow, optical three-dimensional modeling may become difficult, or the strength of the obtained core may be insufficient, and when the toughness of the obtained core is too high, When the core 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 core is difficult to occur. In order to obtain a sufficiently foaming core, the type of photopolymerizable compound constituting the optical three-dimensional resin composition, the type of photopolymerization catalyst, the component composition of the optical three-dimensional resin composition, etc. While selecting, it is preferable to adjust the type, thermal expansion performance, content, and the like of the thermally expandable microcapsules.

The resin composition for optical three-dimensional modeling used for the production of the core of the present invention, together with a photopolymerizable compound, a photopolymerization initiator and a thermally expandable microcapsule, and optionally a polyalkylene ether compound, impairs the effects of the present invention. Unless necessary, colorants such as pigments and dyes, antifoaming agents, leveling agents, thickeners, flame retardants, antioxidants, fillers (crosslinked polymer particles, silica, glass powder, ceramic powder, metal Powders, etc.), and a suitable amount of one or more types of resins for modification may be contained.

In manufacturing a core by performing optical three-dimensional modeling using the resin composition for optical three-dimensional modeling, any conventionally known optical three-dimensional modeling method and apparatus can be used. 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 core (three-dimensional modeled object) can be mentioned by repeating the lamination | stacking operation formed in this.

As the active energy rays at that time, as described above, ultraviolet rays, electron beams, X-rays, radiation, high frequencies and the like can be mentioned. Among them, ultraviolet rays having a wavelength of 300 to 400 nm are preferably used from an economical viewpoint. 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 manufacturing a core by performing optical three-dimensional modeling using a resin composition for optical three-dimensional modeling containing a heat-expandable microcapsule, the heat-expandable microcapsule is located above the resin composition for optical three-dimensional modeling. If it is floating and separated, it becomes difficult to perform optical modeling smoothly, and it becomes difficult to obtain a core in which thermally expandable microcapsules are uniformly dispersed. Therefore, a resin composition for optical three-dimensional modeling It is preferable to perform optical modeling while stirring the object. Further, by adjusting the viscosity of the resin composition for optical three-dimensional modeling, adding a leveling agent, etc., it is possible to suppress the floating separation of the thermally expandable microcapsules in the resin composition for optical three-dimensional modeling. .

The shape, structure, size and the like of the core of the present invention are not particularly limited, and the shape, structure, size and the like corresponding to the types of hollow molded body, mold, and other molded bodies manufactured using the core of the present invention are not limited. do it.

The core of the present invention may have a hollow shape or a solid shape.
Even if the core of the present invention has a hollow shape, problems such as insufficient strength of the core and deterioration of workability at the time of molding occur when a hollow molded body or a mold is produced using the core. It is preferable to make the core hollow. By forming the core into a hollow shape, the molding time can be reduced and the core can be shortened when the core is manufactured by performing the optical three-dimensional modeling using the resin composition for optical three-dimensional modeling containing the thermally expandable microcapsules. The resin composition for optical three-dimensional modeling used for manufacturing can be reduced. Moreover, when the core is made hollow, when the used core is heated to expand the thermally expandable microcapsule contained in the core to foam and collapse the core, the hollow direction of the core ( Foaming is performed smoothly in the inner direction), and the foaming / collapse of the core is further promoted, and the foaming pressure on the material layer formed on the outer surface of the core is reduced (reduced), and the outer surface of the core The material layer formed on the substrate is not easily damaged.

The wall thickness of the hollow core when the core is made into a hollow shape is not particularly limited, and the shape, structure, type of material constituting the core, and the thermally expandable microcapsule contained in the core It can be determined according to the type and amount, the type of the molded body produced using the core, and the like.

The use form (use) of the core of the present invention is not particularly limited. For example, a core, sand mold, gypsum mold, heat resistant resin mold (for example, FRP type) for producing a hollow molded body made of an organic polymer material. Can be used as a core or the like for manufacturing.

Therefore, the present invention
(A) (a) a step of forming a layer of a material for producing a hollow molded body on the surface of the core of the present invention containing a thermally expandable microcapsule;
(B) a step in which a core having a layer of a material for producing a hollow molded body formed on the surface is heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule contained in the core and foamed to be collapsed; and
(C) a step of discharging the foamed / collapsed material derived from the core from the inside of the hollow molded body formed from the material for manufacturing the hollow molded body;
A method for producing a hollow molded article characterized by comprising:
(B) (α) a step of forming a layer of a mold forming material on the surface of the core of the present invention containing thermally expandable microcapsules;
(Β) a step in which a core having a layer made of a mold-forming material formed on the surface is heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule contained in the core and foamed to be collapsed; and
(Γ) discharging the foam / collapsed material derived from the core from the inside of the mold formed from the mold forming material;
A method of manufacturing a mold having
(B ′) A method for producing a molded body in which the mold obtained in (B) is filled with a fluid molded body production material and cured or solidified, and then the mold is separated;
Is included.

Below, the manufacturing method of the hollow molded object of (A), the manufacturing method of the type | mold of (B), and the manufacturing method of the molded object of (B ') are demonstrated.
[Production of Hollow Molded Body According to (A) above]
In manufacturing the hollow molded body by the above (A), in the step (a), (a-1) the surface of the core of the present invention is coated by coating or the like without using the outer mold. A method of forming a layer of a material for manufacturing a hollow molded body, or (a-2) the core of the present invention is disposed in an outer mold, and the surface of the core and the inner surface of the outer mold are A method may be employed in which the voids formed between these are filled with a material for producing a hollow molded body.

In performing the step (a), if a release agent (for example, silicone, paraffin, etc.) is applied to the surface of the core, it becomes easy to take out the foamed / collapsed material derived from the core from the hollow molded body. If a mold release agent is applied to the surface of the core and then water is further applied thereto, it becomes easier to take out the foamed / collapsed material derived from the core from the hollow molded body.

Further, in the step (a), when the method (a-2) using an outer mold is employed, a layer of a material for manufacturing a hollow molded body having a predetermined thickness is easily and reliably formed on the surface of the core. be able to.

The type and production method of the outer mold are not particularly limited, and an outer mold suitable for each situation can be used according to the shape, structure, size, application, etc. of the hollow molded body for production.
If both the core and the outer mold are obtained by optical three-dimensional modeling using the resin composition for optical three-dimensional modeling, even if it is a hollow molded body having a complicated shape or structure, Even a small hollow molded body can be produced smoothly. At that time, the kind of the resin composition for optical three-dimensional modeling used for manufacturing the outer mold is not particularly limited, and a resin composition for optical three-dimensional modeling that has been conventionally known is used that is suitable for each situation. An outer mold may be manufactured.

When a hollow molded body is manufactured by the method (A), the hollow molded body manufacturing material may be used when covering the surface of the core or filling the gap between the core and the outer mold. Has fluidity at a temperature lower than the expansion start temperature of the thermally expandable microcapsule contained in the core and can be satisfactorily coated on the core, or can be satisfactorily filled in the voids in the mold, In the case of a curable or polymerizable material, it is necessary to use a material that is cured or polymerized at a temperature lower than the expansion start temperature of the thermally expandable microcapsule.

Next, the heating, foaming / collapse of the core in the above step (b) is performed by (b-1) foaming by heating the core on which a layer for forming a molded product is formed on the surface without using an outer mold. -It may be carried out by a method of collapsing, or (b-2) A hollow molded body is manufactured by arranging the core in the outer mold and filling the gap between the core and the outer mold with the material for manufacturing the hollow molded body. The core formed with the material layer may be removed from the outer mold together with the material layer for manufacturing the hollow molded body and heated to foam or collapse, or (b-3) hollow molded on the surface You may carry out by the method of heating and foaming / disintegrating in the state which has arrange | positioned the core which formed the layer of material for body manufacture in the outer mold | type.

In the case of the above methods (b-1) and (b-2), it is necessary to use a material that maintains a solid state without flowing at the temperature at the time of heating, foaming / disintegration as a material for producing a hollow molded body It is. At that time, in order to obtain a hollow molded body having a predetermined thickness and dimensions, it is not damaged by the temperature and pressure (foaming pressure) at the time of heating, foaming / collapse, and is permanently deformed, stretched, strained, etc. It is desirable to use a material that does not generate heat (for example, an elastic polymer material having excellent heat resistance, heat-resistant FRP, or the like).

In the case of the above method (b-3), the material for producing a hollow molded body may flow somewhat at the temperature at the time of heating and foaming, but the shape, wall thickness, In order to obtain a hollow molded body having dimensions, a material that does not melt at the temperature at the time of heating, foaming / collapse, and that does not break or deform due to the foaming pressure at the time of heating, foaming / collapse (for example, heat resistance) It is preferable to use a polymer material excellent in

In the present invention, an organic polymer material is preferably used as a material for producing a hollow molded body in the production of the hollow molded body by the method (A), and a specific example thereof is a polyurethane-based thermoplastic elastomer. , Polyolefin Meter Thermoplastic Elastomer, Polyester Thermoplastic Elastomer, Polyamide Thermoplastic Elastomer, Fluorine Thermoplastic Elastomer, Silicone Thermoplastic Elastomer, etc .; Polypropylene, Cyclic Polyolefin, Thermoplastic Polyester Resin, Polyamide, Plasticization Examples thereof include thermoplastic resins such as polyvinyl chloride; curable resins such as epoxy resins, phenol resins, and polyurethane resins.

In the above step (c), the foamed / collapsed material derived from the core is discharged from the inside of the hollow molded body to the opening formed by the size of the foam / collapsed material derived from the core formed in the hollow molded body. When it is smaller than the size of the part, it can be performed by turning the opening of the hollow molded body downward or by vibrating the hollow molded body with the opening of the hollow molded body facing downward.

Also, when the size of the foam / collapse material derived from the core is larger than the size of the opening formed in the hollow molded body, the foam / collapse contained in the hollow molded body by pressing the hollow molded body from the outside Depending on the size of the opening or the size of the opening formed in the hollow molded body, a crushing means such as a crushing rod is inserted through the opening to reduce the size of the foamed / collapsed material and discharge it to the outside. A method etc. can be adopted.

When the hollow molded body is formed from an elastic polymer or a flexible polymer (soft polymer), even if pressed from the outside to reduce the size of the foam / collapsed material derived from the core, Since the original shape and size are restored by stopping the pressing, the foamed / collapsed material can be discharged smoothly.

Although it is not limited at all, an example in the case of producing a hollow molded body by the method (A) using the core of the present invention containing a thermally expandable microcapsule will be described below with reference to FIG. Explained.

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), after the core 1 is disposed in the outer mold 3 with the molding space 4 provided, the polymer is placed in the molding space 4 as shown in FIG. 1 (c). A material for manufacturing a hollow molded body made of a material or a polymerizable material is introduced, and a layer 5 of the material for manufacturing a hollow molded body is formed on the surface of the core 1.

Next, as shown in FIG. 1 (d), after the core 1 having the surface formed with the layer 5 for manufacturing a hollow molded body is taken out from the outer mold 3, the thermal expansion contained in the core 1 is taken out. The core 1 is expanded and collapsed by heating the expandable microcapsule 2 by heating to a temperature equal to or higher than the expansion start temperature of the expandable microcapsule, as shown in FIG. This foam / collapse product 6 is used.

Finally, the foamed / collapsed material 6 derived from the core is taken out of the hollow molded body. At that time, if the foamed / collapsed product 6 is not in the form of strips, the foamed / collapsed material 6 is taken out into the form of strips by pressing from outside. Thereby, the hollow molded body 7 shown in FIG. 1 (f) can be obtained.

In FIG. 1, the shape of the core is hollow, but the shape is not limited to this, and the core may have a solid structure according to the type and nature of the material for manufacturing the hollow molded body. .
The core of the present invention containing a thermally expandable microcapsule has a strength that can sufficiently withstand a molding operation or pressure when manufacturing a hollow molded body by increasing the wall thickness even when the hollow core is formed. be able to. Even if the wall thickness of the hollow core is increased or the core is solid, it is foamed by heating to a temperature equal to or higher than the expansion start temperature of the heat-expandable microcapsule and collapses into strips. Or it can be easily discharged to the outside from the hollow molded body as a foamed / collapsed material that can be easily disintegrated into strips.

When an elastic polymer is used as a material for manufacturing a hollow molded body, as shown in FIG. 1, a core 1 having a surface 5 of a material for manufacturing a hollow molded body (elastic polymer) formed on the surface is used as an outer mold 3. The hollow molded body 7 formed from the material for producing a hollow molded body (elastic polymer) swelled at the time of foaming even if the core is foamed / collapsed after being removed from the When is removed, it can return to its original size due to its elasticity.

Depending on the physical properties (heat resistance, softening point, presence / absence of elasticity, strength, etc.) of the material for manufacturing a hollow molded body, the foaming / disintegration treatment by heating the core formed with a layer of the material for manufacturing the hollow molded body on the surface As shown in FIG. 1, it may be performed after taking out from the outer mold, or may be performed while being put in the outer mold as described above.

[Manufacture of mold and molded body according to (B) and (B ′) above]
A layer of a mold forming material is formed on the surface of the core of the present invention containing a thermally expandable microcapsule [step (α) of (B)].

At this time, as a mold forming material, a layer can be formed on the surface of the core at a temperature lower than the expansion start temperature of the thermally expandable microcapsule contained in the core, It is necessary to use a material that can sufficiently withstand the temperature at which the mold is filled. Although not limited at all, examples of the mold forming material include sand mold material, gypsum mold material, FRP mold material, and silicone resin.

In this case, if a release agent is applied to the surface of the core, it becomes easy to take out the foamed / collapsed material derived from the core from the mold. If a mold release agent is applied to the surface of the core and then water is further applied thereto, it becomes easier to take out the foamed / collapsed material derived from the core from the mold.

Next, in the step (β), after the core having the layer made of the mold forming material formed on the surface is heated above the expansion start temperature of the thermally expandable microcapsule contained in the core, foamed / collapsed In the step (γ), the foamed / collapsed material derived from the core is discharged from the inside of the mold formed from the mold forming material to obtain the mold.

In forming the layer of the mold forming material on the surface of the core in the step (α), for example, there is a portion where the layer of the mold forming material is not formed between the upper half and the lower half of the core. Thus, by applying the mold forming material to the surface of the core, a split mold can be manufactured instead of a hollow mold.

A mold (solid molded body and hollow molded body) can be produced by separating the mold after filling the resulting mold with a material for producing a fluid molded body and curing or solidifying it. .

In the methods (B) and (B ′), when a sand mold or a gypsum mold is produced using a sand mold material or a gypsum mold forming material as a mold forming material, the molten metal in the sand mold or the gypsum mold is obtained. By filling, a metal molded body (so-called casting) can be produced.

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 bending elastic 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 and the like.

(3) Thermal deformation temperature of the three-dimensional structure:
Using a three-dimensional model (bar-shaped test piece conforming to JIS K-7171) produced in the following reference example, using “HDT Tester 6M-2” manufactured by Toyo Seiki Co., Ltd., the test piece was 0.45 MPa. And the heat distortion temperature of the test piece was measured according to JIS K-7207 (Method B).

(4) Foamability of the three-dimensional structure:
The foamed state when a three-dimensional model (bar-shaped test piece conforming to JIS K-7171) prepared in the following reference example similar to the above (3) is placed in a thermostatic bath at 150 ° C. and heated for 10 minutes. evaluated.

<< Reference Example 1 >> [Manufacture of a three-dimensional structure containing thermally expandable microcapsules]
(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 Perform stereolithography in 2 minutes to produce a bar-shaped test piece according to JIS K-7171 for measuring physical properties and evaluating foamability, and heating the obtained test piece 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) The post-cured test piece obtained in (2) above was placed in a thermostatic bath at 150 ° C. and heated for 10 minutes, and foamed to about 30 times the volume of the three-dimensional object before heating. The bar shape was completely lost, and when the foam produced 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.
<< Reference Example 2 >> [Manufacture of a three-dimensional structure containing thermally expandable microcapsules]
(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) Optical modeling is performed in the same manner as (2) of Reference Example 1 using the resin composition for optical three-dimensional modeling obtained in (1) above, 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) The post-cured test piece obtained in (2) above was placed in a thermostatic bath at 150 ° C. and heated for 10 minutes, and foamed to about 10 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 3 >> [Manufacture of a three-dimensional structure containing a thermally expandable microcapsule]
(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) The post-cured test piece obtained in (2) above was placed in a thermostatic bath at 150 ° C. and heated for 10 minutes, and 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.

<< Example 1 >> [Manufacture of core and hollow molded body]
(1) The same optical as in (2) of Reference Example 1 using the same resin composition for optical three-dimensional modeling containing thermally expandable microcapsules as used in (1) of Reference Example 1. A hollow core having the same shape as shown in FIG. 1A was manufactured by adopting the three-dimensional modeling conditions (volume without core = about 25 cm ³ , wall thickness = 1.25 mm).

(2) The core obtained in the above (1) is placed inside an outer mold (manufactured by optical three-dimensional modeling) having substantially the same outer shape as the core, and the surface of the core and the outer inner surface Is filled with a raw material for producing a thermoplastic polyurethane elastomer ("PL-05" manufactured by Polysys Co., Ltd.), and a thermoplastic polyurethane elastomer layer is formed on the outer peripheral surface of the core Formed.

(3) When a core having a surface formed with a thermoplastic polyurethane elastomer layer is taken out from the outer mold and heated at 155 ° C. for 15 minutes, a part of the foam / collapsed material derived from the core is made of thermoplastic polyurethane elastomer. The core foamed and collapsed while being ejected from the opening of the hollow molded body (substantially the same shape as the core). The foamed / collapsed material derived from the core was powdery.

(4) The foamed / collapsed material derived from the core was completely discharged from the thermoplastic polyurethane hollow molded body to obtain a thermoplastic polyurethane hollow molded body.

By using the core of the present invention containing a thermally expandable microcapsule, a hollow molded body, a mold and a solid molded body having a complicated shape and structure, a small-sized hollow molded body, a mold and other molded bodies Can be manufactured smoothly.

DESCRIPTION OF SYMBOLS 1 Core 2 Thermally expansible microcapsule 3 Outer mold | type 4 Molding space 5 Material for hollow molded object manufacture 6 Foam and collapsed substance originating in a core 7 Hollow molded object

Claims (17)

1. A core that contains thermally expandable microcapsules and foams and collapses when heated above the expansion start temperature of the thermally expandable microcapsules.
2. The optical three-dimensional modeling is performed using a resin composition for optical three-dimensional modeling containing a photopolymerizable compound, a photopolymerization initiator, and a thermally expandable microcapsule. The core.
3. The heat-expandable microcapsule comprises 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. The core described in
4. 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 resin composition for optical three-dimensional modeling used for the production of the core. Or the core described in 3.
5. The photopolymerizable compound in the optical three-dimensional modeling resin composition used for the production of the core is selected from one or more radically polymerizable compounds, one or more cationically polymerizable compounds, or both. 5. The core according to any one of 4 above.
6. The core according to claim 5, wherein the photopolymerizable compound is a radical polymerizable compound and the photopolymerization initiator is a photoradical polymerization initiator.
7. The core according to claim 5 or 6, wherein the radical polymerizable compound is a di (meth) acrylate compound having two (meth) acryloyloxy groups.
8. The core according to claim 7, wherein the di (meth) acrylate compound having two (meth) acryloyloxy groups is a di (meth) acrylate of a substituted or unsubstituted bisphenol.
9. The core according to any one of claims 6 to 8, wherein the photo radical polymerization initiator is benzyl or a dialkyl acetal compound thereof.
10. The core according to any one of claims 2 to 9, wherein the resin composition for optical three-dimensional modeling used for manufacturing the core further contains a polyalkylene ether compound.
11. The core according to any one of claims 1 to 10, which is a core for use in the production of a hollow molded body made of an organic polymer.
12. (A) forming a layer of a material for producing a hollow molded body on the surface of the core according to any one of claims 1 to 11;
    (B) a step in which a core having a layer of a material for producing a hollow molded body formed on the surface is heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule contained in the core and foamed to be collapsed; and
    (C) a step of discharging the foamed / collapsed material derived from the core from the inside of the hollow molded body formed from the material for manufacturing the hollow molded body;
    The manufacturing method of the hollow molded object which has this.
13. In the step (a) of forming a layer of the material for manufacturing a hollow molded body on the surface of the core, the core is disposed in the outer mold, and a gap formed between the surface of the core and the inner surface of the outer mold is formed. Filling the material for producing a hollow molded body, and the heating and foaming in the step (b) are carried out while the core is placed in the outer mold, or a layer of the material for producing the hollow molded body is formed on the surface. The manufacturing method of the hollow molded object of Claim 12 performed by taking out a core from an outer type | mold.
14. The method for producing a hollow molded body according to claim 12 or 13, wherein the material for producing the hollow molded body is an organic polymer material or an organic polymerizable material.
15. The method for producing a hollow molded article according to claim 13 or 14, wherein the outer mold is produced by optical three-dimensional modeling using a resin composition for optical three-dimensional modeling.
16. (Α) forming a layer of a mold forming material on the surface of the core according to any one of claims 1 to 11;
    (Β) a step in which a core having a layer made of a mold-forming material formed on the surface is heated to a temperature higher than the expansion start temperature of the thermally expandable microcapsule contained in the core and foamed to be collapsed; and
    (Γ) discharging the foam / collapsed material derived from the core from the inside of the mold formed from the mold forming material;
    A method of manufacturing a mold having
17. A method for producing a molded body in which the mold obtained in claim 16 is filled with a fluid molded body production material and cured or solidified, and then the mold is separated.

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