JPH08164440A - Resin compound of optical stereoscopic shaping for lost form master pattern of investment casting and investment casting method - Google Patents

Abstract

PURPOSE: To provide a resin compound for optical sterescopic shaping, by which a master pattern does not cause cracking and strain of a mold, when a resin not requiring post hardening treatment is embedded in refractory and heated as a lost foam master pattern of investment casting process and a investment casting process in which the shape obtained is used for a lost form pattern. CONSTITUTION: The compound contains, as essential components, a cation polymerization organic compound of 100 pts.wt., an energy live sensitive cation polymerization starter of 0.05-10 pts.wt. and a thermoplastic mateial, having <150 deg.C melting point and <=1mmHg vapor pressure at 20 deg.C, of 5-50 pts.wt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for optical three-dimensional molding and an optical three-dimensional molding method using the same. More specifically, the obtained molded article is used as a disappearance prototype of an investment casting method in a refractory material. The present invention relates to an optical three-dimensional molding method in which the prototype does not cause cracking or distortion of the mold when it is embedded and heated.

[0002]

2. Description of the Related Art The investment casting method is a casting method which produces a product having a dimensional accuracy several steps higher than that of the sand casting method. As is well known, castings made by the investment casting method are manufactured by the following steps.

A durable material such as aluminum or steel is machined into the shape of the injection mold.

A prototype is created by injecting a material that can be removed by heating, such as wax or a thermoplastic resin, into the injection mold obtained in.

The prototype obtained in step 1 is bonded to a runner made of wax to form a tree.

The tree obtained in the above step is dipped in a refractory slurry in which refractory powder and a liquid binder are mixed to perform coating.

Next, the refractory powder is sprinkled and then dried for several hours.

The operations from to are repeated several times to 10 times to form a shell having a predetermined thickness, and finally a backup coat is applied and further dried.

Heating the shell in an autoclave,
The prototype is melted and removed.

Firing is performed in a heating furnace.

Casting a casting metal into the obtained shell,
Cool to solidify to form a casting, then break the shell and remove the casting.

This method is relatively time consuming and costly due to the time and expense of the machining required to manufacture the injection mold. As a result, this method is not practical when a relatively small lot of product is desired.

The prior art is expensive even when a relatively large number of products is desired. This is because this method requires the production of a large number of injection molds with various dimensions. This is because the size of the master needed to compensate for the mold shrinkage or casting shrinkage and machining must be determined empirically. Injection molds of various sizes are redesigned until the proper size is determined to achieve the desired dimensions of the casting. Therefore, a method that does not use an expensive injection mold is advantageous from the standpoint of economy and productivity.

As described in JP-A-60-247515, the optical three-dimensional molding method is as follows. First, various photo-curable resins are put in a container, and an argon laser, a helium cadmium laser, and a semiconductor laser are placed from above. By irradiating an arbitrary portion of the resin with such a beam, and continuously irradiating the resin, the portion of the resin irradiated with the beam is cured, thereby forming a cured layer. Subsequently, one layer of the above-mentioned resin having photo-curability is supplied onto the cured layer, and the resin is cured in the same manner as above to perform a lamination operation to obtain a cured layer continuous with the cured layer. This is a method of obtaining a desired three-dimensional object by repeating this operation.

Conventionally, as a resin used in the above-mentioned optical three-dimensional molding, there is a radically polymerizable resin composition, which is a photosensitive resin mainly containing polyester acrylate, urethane acrylate, epoxy acrylate, polyether acrylate and the like. It has been known. For example, JP-A-2-145616 discloses an optical three-dimensional molding resin containing fine particles having an apparent specific gravity difference of less than 0.2 with a liquid resin for the purpose of reducing deformation, and JP-A-2-208305. The official gazette discloses a resin composition in which a large amount of a specific difunctional acrylate is added to a reactive oligomer. Further, in order to improve the accuracy of the shaped article, JP-A-3-15520 discloses a composition comprising an ethylenically unsaturated monomer, a photoinitiator and an insoluble latent radiation polarizing substance, and JP-A-3-15520.
41126 discloses a composition comprising an ethylenically unsaturated monomer, a photoinitiator and a soluble latent radiation polarizer. Further, JP-A-4-85314 discloses a resin composition containing a silicone urethane acrylate, a compound having a polyfunctional ethylenically unsaturated bond, and a polymerization initiator.

As another optical three-dimensional modeling resin,
Cation-curable resins are known. For example, Japanese Patent Laid-Open No. 1-21
Japanese Patent No. 3304 describes an invention characterized by containing an energy ray-curable cationically polymerizable organic compound and an energy ray-sensitive cationic polymerization initiator. Kohei
JP-A 2-28261 discloses a resin having a low shrinkage ratio and a high resolution obtained by partially mixing an energy ray-curable cationically polymerizable organic compound with an energy ray-curable radically polymerizable organic compound. Further, JP-A No. 2-80423 discloses a resin composition in which a vinyl ether resin, a cationic polymerization initiator, and a radical curable resin and a radical curable initiator are mixed with a photocurable cationic polymerizable epoxy resin. There is.
Further, JP-A-2-75618 discloses that an energy ray-curable cationically polymerizable organic compound, an energy ray-sensitive cationic polymerization initiator, an energy ray-curable radically polymerizable organic compound, an energy ray-sensitive radical polymerization initiator and a hydrogen group-containing Disclosed is a resin composition for optical three-dimensional modeling, which contains a polyester.

[0017]

Attempts to use a three-dimensional object obtained by the optical three-dimensional molding method as a prototype of the investment casting method have not been successful until now. This three-dimensional object is a hard thermosetting polymer in which a cured product of a resin having photocurability is cross-linked, and when this three-dimensional object is used as a prototype, it expands without being melted when heated. This is because the refractory material in which the prototype is embedded will be destroyed or distorted before it can be heated sufficiently for removal.

To solve this problem, Tokuhyo 4-500929
Discloses a resin composition comprising an ethylenically unsaturated material, a photoinitiator, and an ethylenically unsaturated material and a non-reactive thermoplastic material. However, since the radically polymerizable ethylenically unsaturated material is used as the main component, the curing rate at the time of curing becomes low due to the inhibition of curing by oxygen. It is necessary to perform a "post-curing treatment" for applying heat, and there is a drawback that the molded article is easily deformed during this post-curing treatment.

The object of the present invention is to prevent post-curing treatment from deforming by not requiring a post-curing treatment, and to prevent the cured product from destroying the refractory material when heated by the composition peculiar to the present invention. To provide a resin composition for use.

[0020]

As a result of intensive studies to solve the above-mentioned problems, the present inventors did not require a post-curing treatment, and embedded a cured product in a refractory material as a disappearance prototype of an investment casting method. The resin for optical three-dimensional modeling that does not cause cracking or distortion of the mold when heated by, the optical three-dimensional modeling method using this, and the investment casting using the model obtained by this modeling method as the disappearing master He found a method and completed the present invention.

That is, the present invention comprises (1) 100 parts by weight of a cationically polymerizable organic compound as an essential component,
(2) The energy ray-sensitive cationic polymerization initiator is 0.0
5-10 parts by weight and (3) 5-50 parts by weight of a thermoplastic material having a melting point lower than 150 ° C. and a vapor pressure at 20 ° C. of not more than 1 mmHg is eliminated. It is a resin composition for optical three-dimensional modeling for producing a prototype (hereinafter referred to as "optical modeling resin composition for investment").

The present invention further comprises (1) to 150 parts by weight of (4) a radical-polymerizable organic compound and (5) 0.01 to 15 parts by weight of an energy ray-sensitive radical polymerization initiator, in addition to the above resin composition. A stereolithography resin composition for investment, which comprises a part.

Further, the present invention is a method for producing a disappearing prototype of the investment casting method, in which any surface of the above resin composition is irradiated with energy rays to cure the energy ray irradiated surface of the resin composition. To form a cured layer having a desired thickness, further supply the resin composition described above on the cured layer, and similarly cure the resin composition to obtain a cured product continuous with the cured layer. This is an optical three-dimensional modeling method characterized in that a three-dimensional three-dimensional object is obtained by repeating this operation.

Further, the present invention is an investment casting method characterized in that the molded article formed by the above-mentioned optical three-dimensional molding method is used as a disappearance prototype.

The (1) cationically polymerizable organic compound, which is an essential component of the stereolithography resin composition for investment of the present invention, is polymerized by an energy ray-sensitive cationic polymerization initiator activated by energy ray irradiation, or A compound that causes a crosslinking reaction. Examples thereof include epoxy compounds, cyclic lactone compounds, cyclic acetal compounds, cyclic thioether compounds, spiro orthoester compounds, vinyl compounds and the like, and one or more of these can be used. Of these, epoxy compounds are suitable. As the epoxy compound, aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin and the like are suitable.

Specific examples of the aromatic epoxy resin include polyhydric phenols having at least one aromatic ring or polyglycidyl ethers of alkylene oxide adducts thereof, such as bisphenol A and bisphenol F, and further alkylene oxides. Examples thereof include glycidyl ether of a compound to which is added, epoxy novolac resin, and the like.

Further, specific examples of the alicyclic epoxy resin are obtained by epoxidizing a polyglycidyl ether of a polyhydric alcohol having at least one alicyclic ring or cyclohexene or a cyclopentene ring-containing compound with an oxidizing agent. And cyclopentene oxide-containing compounds. For example, hydrogenated bisphenol A diglycidyl ether, 3,
4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-metadioxane, bis (3,4-epoxycyclohexyl) Methyl) adipate, vinylcyclohexenedioxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexylcarboxylate, methylenebis (3,4- Epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, epoxyhexahy Rofutaru di -2
-Ethylhexyl and the like.

Specific examples of the aliphatic epoxy resin include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, polyglycidyl esters of aliphatic long-chain polybasic acids, homopolymers of glycidyl acrylate or glycidyl methacrylate, and glycidyl. Examples thereof include acrylate or glycidyl methacrylate copolymers. Typical compounds are 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol tetraglycidyl ether, dipentaerythritol. Hexaglycidyl ether, polyethylene glycol diglycidyl ether,
Glycidyl ethers of polyhydric alcohols such as diglycidyl ether of polypropylene glycol. In addition, polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as propylene glycol and glycerin, diglycidyl esters of aliphatic long-chain dibasic acids, etc. Can be mentioned. Furthermore, monoglycidyl ethers of higher aliphatic alcohols, phenols, cresols, butylphenols, monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to these, glycidyl esters of higher fatty acids, epoxidized soybean oil, epoxy Examples include octyl stearate, epoxy butyl stearate, epoxidized linseed oil, and epoxidized polybutadiene.

Among the above epoxy compounds, 1
Those containing two or more epoxy groups in the molecule,
(1) Of 100 parts by weight of the cationically polymerizable organic compound,
It is particularly preferable to use 50% by weight or more. The remaining 50% by weight or less may be one having one epoxy group in one molecule, or a cationically polymerizable organic compound other than the epoxy compounds exemplified below.

Specific examples other than the epoxy compound of the cationically polymerizable organic compound (1) that can be used in the present invention include trimethylene oxide, 3,3-dimethyloctacene, and 3,3-dichloromethyloctacene. Oxacene compound. Oxolane compounds such as tetrahydrofuran and 2,3-dimethyltetrahydrofuran. Trioxane, 1,3
-Cyclic acetal compounds such as dioxolane and 1,3,6-trioxanecyclooctane. β-propiolactone, ε
-Cyclic lactone compounds such as caprolactone. Thiirane compounds such as ethylene sulfide and thioepichlorohydrin. Thiethane compounds such as 1,3-propyne sulfide and 3,3-dimethylthietane. Cyclic thioether compounds such as tetrahydrothiophene derivatives. Vinyl compounds such as ethylene glycol divinyl ether, alkyl vinyl ether, 3,4-dihydropyran-2-methyl (3,4-dihydropyran-2-carboxylate), and triethylene glycol divinyl ether. Spiro orthoester compounds obtained by the reaction of epoxy compounds with lactones. Examples thereof include ethylenically unsaturated compounds such as vinylcyclohexene, isobutylene and polybutadiene, and the above derivatives.

In the present invention, as the (1) cationically polymerizable organic compound, one kind or two or more kinds of the above-mentioned cationically polymerizable substances can be blended and used.

The energy ray-sensitive cationic polymerization initiator (2), which is an essential component of the stereolithography resin composition for investment of the present invention, is a compound capable of releasing a substance which initiates cationic polymerization upon irradiation with energy rays. And particularly preferred is a double salt, which is an onium salt that releases a Lewis acid upon irradiation, or a derivative thereof. Typical examples of such compounds include salts of cations and anions represented by the general formula [C] ^{m +} [A] ^m- .

Here, the cation C ^{m +} is preferably onium, and the structure thereof is, for example, [(R ¹ ) _a Z] ^{m +,} wherein R ¹ has ¹ to 60 carbon atoms and is other than carbon. An organic group that can contain any number of atoms. a is an integer of 1 to 5. Each a ¹ of R ¹ is independent and may be the same or different. Further, at least one is preferably an organic group having an aromatic ring as described above. Z is S,
N, Se, Te, P, As, Sb, Bi, O, I, B
An atom or atomic group selected from the group consisting of r, Cl, F, and N = N. In addition, the valence of Z in the cation A ^{m +} is z
Then, it is necessary that the relation of m = a−z holds.

Further, the anion A ^m- is preferably a halide complex, and the structure thereof is, for example, [LX _b ] ^m- where L is a metal or semimetal (which is a central atom of the halide complex). Metalloid), B, P, As, Sb,
Fe, Sn, Bi, Al, Ca, In, Ti, Zn, S
c, V, Cr, Mn, Co and the like. X is halogen. b is an integer of 3 to 7. Further, when the valence of L in the anion A ^m − is c, it is necessary that the relation of m = bc holds.

Specific examples of the anion [LX _b ] ^m-in the above general formula include tetrafluoroborate (BF ₄ ) ^- , hexafluorophosphate (PF ₆ ) ^- , hexafluoroantimonate (SbF ₆ ) ^- , hexafluoro. arsenates (AsF ₆₎ ^-, hexachloroantimonate (SbCl ₆₎ ^-, and the like.

As the anion B ^m- , those having a structure represented by [LX _b-1 (OH)] ^- can also be preferably used.
L, X and b are the same as above.

Other anions that can be used
As a perchlorate ion (ClO _Four)^-, Trifluo
Romethyl sulfite ion (CF₃SO₃)^-, Fluoros
Ruphonate ion (FSO₃)^-Toluene sulphonic acid
Ion, trinitrobenzene sulfonate anion, etc.
You can

In the present invention, it is particularly effective to use an aromatic onium salt among such onium salts. Among them, JP-A-50-151997 and JP-A-50-151997
Aromatic halonium salts described in JP-A-158680, JP-A-50-151997, and JP-A-52-30899
JP-A-56-55420, JP-A-55-1251
Group VIA aromatic onium salts described in JP-A No. 05, etc., Group VA aromatic onium salts described in JP-A No. 50-158698, JP-A No. 56-8428, and JP-A No. 56-14940.
2, oxosulfoxonium salts described in JP-A-57-192429 and the like, aromatic diazonium salts described in JP-A-49-17040, and thiopyrylium salts described in US Pat. No. 4,139,655 are preferable. Other preferable examples include iron / allene complex and aluminum complex / photolytic silicon compound-based initiator.

The content of (2) the energy ray-sensitive cationic polymerization initiator in the present invention is 0.05 to 10 parts by weight, preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of (1). Is. If the amount is less than 0.05 parts by weight, the resin composition is not sufficiently cured, and if the amount is more than 10 parts by weight, a resin having sufficient strength cannot be obtained. The object of the present invention cannot be achieved except for the mixing ratio shown here.

(3) A thermoplastic material having a melting point lower than 150 ° C. and a vapor pressure at 20 ° C. of 1 mmHg or less used in the present invention is an organic compound which is liquid or solid at room temperature.

Typical examples of such thermoplastics include hydrocarbons such as diamylbenzene, triamylbenzene, tetraamylbenzene, dodecylbenzene, didodecylbenzene, tetralin and biphenyl, 2-ethylbutanol, n-. Heptanol, 2-heptanol, n-octanol, 2-octanol, 2-ethylhexanol,
3,3,5-Trimethylhexanol, nonanol, n-decanol, undecanol, n-dodecanol, trimethylnonyl alcohol, tetradecanol, heptadecanol, cyclohexanol, benzyl alcohol, glycidol, furfuryl alcohol, tetrahydrofurfuryl alcohol Alcohols such as α-terpineol, trimethylolpropane and trimethylolpropanecaprolactone adduct (preferably 1 to 20 mol), n-hexyl ether, n-butylphenyl ether, amylphenyl ether, ethylbenzyl ether, diethylene glycol monomethyl ether , Diethylene glycol monoethyl ether, diethylene glycol diethyl ether, polyethylene glycol dimethyl with an average molecular weight of 200 to 2000 Ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, ethers such as polypropylene glycol dimethyl ether having an average molecular weight of 200 to 2000, 2,6,8-trimethylnonanone-4, aceto Ketones such as nylacetone, diacetone alcohol, holone, isophorone, acetophenone, and dipnone, 2-ethylhexyl acetate, benzyl acetate, butyl stearate, amyl stearate, ethyl acetoacetate, isoamyl isovalerate, butyl lactate, amyl lactate , Methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, benzyl benzoate, ethyl cinnamate, methyl salicylate, ethyl abietic acid, abietic acid , Dioctyl adipate, diethyl oxalate, dibutyl oxalate, diamyl oxalate, diethyl malonate, dibutyl tartrate, tributyl citrate, dioctyl sebacate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-2 phthalate. -Ethylhexyl, esters such as dioctyl phthalate, and the like.

Further, polyester, polyvinyl acetate, polymethylmethacrylate, etc. may be used as the high molecular weight thermoplastic.

The blending amount of the thermoplastic material (3) in the resin composition for optical three-dimensional modeling of the present invention is such that the resin component is (1).
In the case of only the cationically polymerizable organic compound, 5 to 5
It is preferably blended in an amount of 0 part by weight, preferably 10 to 30 parts by weight. When the resin component is composed of (1) and (4) a radically polymerizable organic compound, it is 5 to 50% by weight, more preferably 10 to 30% by weight, based on the total amount of (1) + (4). Is preferred.

A molded article made of the resin composition of the present invention is
(3) Since it contains a thermoplastic material, when it is used as a disappearing prototype for investment casting, it melts without expanding when heated during the removal step. Therefore, it can be removed without destroying or distorting the shell. Further, if the blending amount is 5 parts by weight or less, the above characteristics cannot be sufficiently obtained, and if it exceeds 50 parts by weight, the curability is deteriorated, which is not preferable.

The radically polymerizable organic compound (4), which is an essential component of the stereolithography resin composition for investment of the present invention, is polymerized or crosslinked by irradiation with energy rays in the presence of an energy ray sensitive radical polymerization initiator. It is a radically polymerizable compound that reacts and is a compound having at least one unsaturated double bond in one molecule. Examples of such compounds include acrylate compounds, methacrylate compounds, allyl urethane compounds, unsaturated polyester compounds, polythiol compounds, and the like.

Among such radically polymerizable compounds, compounds having at least two or more (meth) acryl groups in one molecule are preferable, for example, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth). Examples thereof include acrylates, polyether (meth) acrylates, and (meth) acrylic acid esters of alcohols.

Here, the epoxy (meth) acrylate is, for example, an acrylate obtained by reacting a conventionally known aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin and the like with (meth) acrylic acid. Is. Among these epoxy acrylates, particularly preferred is an acrylate of an aromatic epoxy resin, which is a polyglycidyl ether of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof.
It is a (meth) acrylate obtained by reacting with (meth) acrylic acid. For example, bisphenol A or an alkylene oxide adduct thereof and glycidyl ether obtained by the reaction of epichlorohydrin with (meth) acrylic acid are reacted with (meth) acrylate, epoxy novolac resin and (meth). Examples thereof include (meth) acrylate obtained by reacting acrylic acid.

Preferred urethane (meth) acrylates are obtained, for example, by reacting one or more kinds of hydroxyl group-containing polyester or hydroxyl group-containing polyether with hydroxyl group-containing (meth) acrylic acid ester and isocyanates (meth). Examples thereof include acrylates and (meth) acrylates obtained by reacting hydroxyl group-containing (meth) acrylic acid esters with isocyanates.

Preferred as the hydroxyl group-containing polyester used here is a hydroxyl group-containing polyester obtained by reacting one or more fatty acid polyhydric alcohols with one or more polybasic acids. Examples of the aliphatic polyhydric alcohol include 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, and trimethylolpropane. , Glycerin, pentaerythritol, dipentaerythritol and the like. Examples of the polybasic acid include adipic acid, terephthalic acid, phthalic anhydride, and trimellitic acid.

A preferred hydroxyl group-containing polyether is, for example, a hydroxyl group-containing polyether obtained by adding one or more alkylene oxides to an aliphatic polyhydric alcohol. The same compounds as those mentioned above can be exemplified. Examples of the alkylene oxide include ethylene oxide and propylene oxide.

Preferred as the hydroxyl group-containing (meth) acrylic acid ester is, for example, a hydroxyl group-containing (meth) acrylic acid ester obtained by the esterification reaction of an aliphatic polyhydric alcohol and (meth) acrylic acid, As the polyhydric alcohol, the same compounds as those mentioned above can be exemplified.

Among the hydroxyl group-containing (meth) acrylic acid, a hydroxyl group-containing (meth) acrylic acid ester obtained by an esterification reaction of an aliphatic dihydric alcohol and (meth) acrylic acid is particularly preferable, and examples thereof include 2 -Hydroxyl ethyl (meth) acrylate.

As the isocyanates, compounds having at least one or more isocyanate groups in the molecule are preferable, and tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like are used.
Valent isocyanate compounds are particularly preferred.

The polyester (meth) acrylate is preferably a polyester (meth) obtained by reacting a hydroxyl group-containing polyester with (meth) acrylic acid.
It is an acrylate. Preferred as the hydroxyl group-containing polyester used here is an ester value reaction of one or more kinds of aliphatic polyhydric alcohols with one or more kinds of monobasic acids, polybasic acids, and phenols. In the resulting hydroxyl group-containing polyester, examples of the aliphatic polyhydric alcohol include the same compounds as those described above. Examples of the monobasic acid include formic acid, acetic acid, butylcarboxylic acid, and benzoic acid. Examples of polybasic acids include adipic acid, terephthalic acid, phthalic anhydride,
An example is trimellitic acid. As phenols,
Examples thereof include phenol and p-nonylphenol.

The preferred polyether (meth) acrylate is a polyether (meth) obtained by reacting a hydroxyl group-containing polyether with (meth) acrylic acid.
It is an acrylate. Preferred as the hydroxyl group-containing polyether used here is a hydroxyl group-containing polyether obtained by adding one or more alkylene oxides to an aliphatic polyhydric alcohol, and as the aliphatic polyhydric alcohol, The same compounds as those mentioned above can be exemplified. Examples of the alkylene oxide include ethylene oxide and propylene oxide. Preferred (meth) acrylic acid esters of alcohols are obtained by reacting an aromatic or aliphatic alcohol having at least one hydroxyl group in the molecule, and an alkylene oxide adduct thereof with (meth) acrylic acid (meta). ) Acrylate, for example, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, isoamyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate. , Isooctyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobonyl (meth) acrylate, benzyl (meth) acrylate, 1,3-butanediol di (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, tri Examples thereof include methylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

Among these (meth) acrylates, poly (meth) acrylates of polyhydric alcohols are particularly preferable.

These radical-polymerizable organic compounds may be used alone or in combination of two or more depending on the desired performance.

The above-mentioned (4) radically polymerizable organic compound is 1 to 150 parts by weight, preferably 10 to 100 parts by weight, relative to 100 parts by weight of the (1) cationically polymerizable organic compound.
It is blended by weight. If it exceeds this range, the curing rate at the time of curing becomes low due to the inhibition of curing by oxygen, and the post-curing treatment becomes necessary. In addition, it causes curing shrinkage, which causes warpage.

The resin composition of the present invention in which the radical polymerization type resin is blended further improves the curing rate in the case of performing optical three-dimensional modeling, as compared with the case where these are not blended, and is preferable as a resin composition. Become.

The energy ray-sensitive radical polymerization initiator (5), which is an essential component of the stereolithography resin composition for investment of the present invention, is a compound capable of initiating radical polymerization by irradiation with energy rays, and is acetophenone. Preferred compounds are ketone compounds such as compounds, benzoin ether compounds, benzyl compounds and thioxanthone compounds. Examples of the acetophenone compound include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4'-isopropyl-2
-Hydroxy-2-methylpropiophenone, 2-hydroxy-2-methylpropiophenone, p-dimethylaminoacetophenone, p-tert.-butyldichloroacetophenone,
Examples thereof include p-tert.-butyltrichloroacetophenone and p-azidobenzalacetophenone.

Examples of the benzoin ether compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether and the like. Benzyl compounds include benzyl, benzyl methyl ketal, and benzyl-β.
-Methoxyethyl acetal, 1-hydroxycyclohexyl phenyl ketone and the like can be mentioned.

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

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

These energy ray sensitive radical polymerization initiators may be used alone or in combination of two or more depending on the desired performance.

The above-mentioned (5) energy ray-sensitive radical polymerization initiator is used in an amount of 0.01 to 100 parts by weight of (1) energy ray-curable cationically polymerizable organic compound.
15 parts by weight, preferably 0.1 to 15 parts by weight is blended. If it exceeds this range, a resin having sufficient strength cannot be obtained, and if it falls below this range, the resin is not sufficiently cured.

The resin composition for optical three-dimensional modeling of the present invention may contain a photosensitizer, various homogeneously soluble thermoplastic resins and the like, though not essential, if necessary. For example,
By using in combination with a photosensitizer such as benzophenone or benzoin isopropyl ether, the curing speed in the case of performing optical three-dimensional molding is further improved as compared with the case where these are not blended, and it becomes a preferable resin composition. .

If desired, a heat-sensitive cationic polymerization initiator, a coloring agent such as a pigment or a dye, a leveling agent, an antifoaming agent, a thickener, a flame retardant, an antioxidant may be added as long as the effects of the present invention are not impaired. Various resin additives such as agents may also be added.
Examples of the heat-sensitive cationic polymerization initiator include aliphatic onium salts described in JP-A-57-49613 and JP-A-58-37004.

In the present invention, the above-described photosensitizer, various homogeneously soluble thermoplastic resins, heat-sensitive cationic polymerization initiators, pigments, dyes, etc. may be used, if desired, within a range that does not impair the effects of the present invention. Colorants, leveling agents, defoaming agents, thickeners, flame retardants, various resin additives such as antioxidants can be used in combination in the range of normal use, in terms of distortion of the shaped article, It is preferably 50% by weight or less based on the total amount of the stereolithography resin composition for investment of the present invention.

Active energy rays for curing the resin composition of the present invention include ultraviolet rays, electron beams, X-rays, radiation, high frequency waves, etc., and ultraviolet rays are economically most preferable. Examples of the light source of ultraviolet rays include an ultraviolet laser, a mercury lamp, a xenon lamp, a sodium lamp, and an alkali metal lamp. Among them, a laser beam is particularly preferable because it has good light-collecting properties.

By using the resin composition of the present invention, it is possible to directly prepare an extinction mold of the investment casting method from CAD data without using a mold, and further perform investment casting by using this as a master mold. It is possible to produce investment casting products of various kinds and in small quantities.

Next, the optical three-dimensional modeling method and investment casting method of the present invention will be described in detail.

To carry out the optical three-dimensional molding method of the present invention, first, (1) a cationically polymerizable organic compound, (2) an energy ray-sensitive cationic polymerization initiator, (3) a thermoplastic resin having a melting point lower than 150 ° C. From the material, (4) radically polymerizable organic compound, and (5) energy ray sensitive radical polymerization initiator, a resin composition for optical stereolithography for producing a disappearing prototype of the investment casting method is obtained.

This step may be a known step, but, for example, (1) to (5) are sufficiently mixed. Specific mixing methods include, for example, a stirring method utilizing a stirring force accompanying the rotation of a propeller, a roll kneading method, and the like.
The preferable compounding ratios of the above (1) to (5), and the types of additives to be compounded and the compounding ratio thereof as needed are used in the above-mentioned optical three-dimensional modeling resin composition (1) to (. It is possible to use the same range or type as the preferable blending ratio of 5), the type of additive to be blended if necessary, and the blending ratio thereof. The resin composition for optical three-dimensional modeling thus obtained is in a liquid state at room temperature.

Next, an arbitrary surface of the resin composition is irradiated with energy rays to cure the surface of the resin composition irradiated with energy rays to form a cured layer having a desired thickness. Then, the above resin composition is further supplied to the resin composition, and the resin composition is similarly cured to perform a lamination operation for obtaining a cured layer that is continuous with the aforementioned cured layer. By repeating this operation, a three-dimensional three-dimensional object is obtained.

As a specific example, the above resin composition is stored in a container as described in, for example, JP-A-60-247515, a light guide is inserted on the surface of the resin composition, and A solid having a desired shape is formed by selectively supplying an active energy ray necessary for curing to the surface of the resin composition via the light guide while relatively moving the container and the light guide. , And so on.

The types of active energy rays used in the optical three-dimensional modeling method of the present invention include ultraviolet rays, electron beams, X-rays, radiation, high frequencies, etc., and ultraviolet rays are economically most preferable. Examples of the light source of ultraviolet rays include an ultraviolet laser, a mercury lamp, a xenon lamp, a sodium lamp, and an alkali metal lamp. Among them, a laser beam is particularly preferable because it has good light-collecting properties.

Investment casting is carried out by the following steps by using the molded article obtained here as a disappearing prototype.

A three-dimensional object obtained by the stereolithography method of the present invention is attached to a runner to obtain an investment casting tree.

Coating is performed by immersing in a refractory slurry in which refractory powder and liquid binder are mixed.

Sprinkle with refractory powder and dry for several hours.

The operations of to are repeated several times to 10 times to form a shell having a predetermined thickness, and finally, a backup coat is applied and further dried.

The shell is heat-treated in a heating furnace.

Molten metal is cast into the obtained shell,
Cool to solidify to form a casting, then break the shell and remove the casting.

[0084]

EXAMPLES Various examples of the present invention will be described below, but the present invention is not limited to the following examples. Further, “part” means “part by weight”.

Example 1 (Preparation of three-dimensional object by stereolithography) (1) As a cationically polymerizable organic substance, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (two epoxy groups) 75 Part 1,4-butanediol diglycidyl lutel (epoxy group 2
25 parts (2) Bis- [4- (diphenylsulfonio) phenyl] sulfide phenylbisdihexafluoroantimonate as an energy ray sensitive cationic polymerization initiator 3 parts (3) Di-2-phthalate as a thermoplastic material Using 10 parts of ethylhexyl, these were thoroughly mixed to obtain a stereolithography resin. The obtained resin composition was a pale yellow transparent liquid.

Next, from a control unit centering on a three-dimensional NC (numerical control) table, an Ar laser (wavelengths 333, 351, 364 nm), an optical system and a control computer on which a container containing the obtained resin composition was placed. Using this three-dimensional modeling experimental system, the resin composition was laminated at a 0.2 mm pitch based on CAD data to obtain a three-dimensional model as shown in FIG.

(Creation of Tree) Nine three-dimensional shaped objects obtained above were adhered to a runner to obtain an investment tree.

(Slurry formulation) A slurry was prepared by a general formulation. The method is briefly described below.

(Primary Slurry) The first-layer to second-layer slurries were mixed and made uniform at the following compounding ratios. The colloidal silica used has an average particle size of 9 μm, a concentration of 30 wt%, and a pH of 9-
10 general commercial products. For example, Adelite AT-3
0S (registered trademark, manufactured by Asahi Denka Kogyo Co., Ltd.) can be used, but it is not limited to the above products as long as it can be used for lost wax. As zircon flour, a general commercial product having an average particle diameter of 200 mesh-pass was used.
For example, # 200 Zircon Flower (Kinsei Mining Co., Ltd.) and the like. The surfactant used was a nonylphenol ethylene oxide-modified type, but is not limited to this as long as the slurry adheres sufficiently to the tree. The defoaming agent was added for the purpose of suppressing foaming by stirring when the above surfactant was added. In this example, a mineral oil type was used. It is also possible to omit the use of the above-mentioned surfactants having a low foaming property.

While the above colloidal silica was placed in a tank and stirred, zircon flour was added little by little and 3/4
A surfactant and a defoaming agent were added at the stage of compounding. Further, the remaining zircon flour was blended and kneaded overnight while being careful not to evaporate the water content, and homogenized. The obtained slurry is Zahn cup No. 4 seconds was 40 seconds. The blending ratio this time was as follows.

Colloidal silica 1000 ml # 200 Zircon flour 4000 g Surfactant 3.0 ml Defoamer 0.1 ml (backup slurry) The above colloidal silica and zircon flour were kneaded at the following compounding ratio to obtain a slurry. The backup slurry obtained is Zahn Cup N.
o. The viscosity was 4 seconds and 9 seconds.

Colloidal Silica 1000 ml # 200 Zircon Flower 3200 g (Creation of Tree) The above tree is dipped in the primary slurry to sufficiently attach the slurry to the surface of the tree. 70 mes before the attached slurry dries
The zircon flour of h was sprinkled evenly (stacking) and then dried for 2 hours at 25 ° C. and 60% RH. After drying the first layer, the tree with the first layer was dipped in the backup slurry, sprinkled with a 70 mesh zircon waller in the same manner, and dried under the above drying conditions for 3 hours.

After drying the second layer, the tree with the first and second layers was dipped in a backup slurry, sprinkled with 30 mesh of fused silica (Toshiba Ceramics glass grain GI), and then dried for 3 hours. This backup process was performed 4 times.

After drying, the tree with the shell was dipped in the backup slurry and dried as it was under the above conditions for 24 hours to obtain a test sample. The steps are summarized in Table 1. The thickness of the obtained shell was about 6 mm.

[0095]

[Table 1]

The type of stucco used, the particle size, the drying time, etc. are not limited to the above description of the invention as long as the shell is formed.

(Test Method) The shell prepared by the above method was heated at 1000 ° C. for 1 hour and burned with an organic substance. The obtained product will be referred to as a fired shell. Molten metal of SUS304 is poured (cast) into the firing shell and cooled. After cooling, the shell was inspected to measure the degree of metal protrusion due to cracking of the shell. Table 2 shows the results. The defect classification is specified as follows.

Destruction before casting: When the shell has clear cracks or is disjointed during firing Cracking: There is no visual defect at the time of firing, but there is a metal bleed after casting. The results were evaluated based on the numerical values calculated by the following non-defective rate calculation formula using the above-mentioned test using a plurality of shells.

[0099]

[Equation 1]

Example 2 In the production of a three-dimensional model by a stereolithography method, as a resin composition, (1) 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 50 parts 1,4-butanediol diglycidylate Luther 30 parts Bisphenol A diglycidyl ether 20 parts (2 epoxy groups) (2) Bis- [4- (diphenylsulfonio) phenyl]
Sulfide phenyl bisdihexafluoroantimonate 3 parts (3) A test was conducted according to the method of Example 1 except that 40 parts of polyethylene glycol dimethyl ether having an average molecular weight of 400 was used. The measurement results are shown in Table 2.

Example 3 In the production of a three-dimensional model by a stereolithography method, as a resin composition, (1) 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 75 parts 1,4-butanediol diglycidylate Lutheran 15 parts Triethylene glycol divinyl ether 10 parts (2) Bis- [4- (diphenylsulfonio) phenyl]
Sulfide phenyl bisdihexafluoroantimonate 3 parts (3) The test was carried out according to the method of Example 1 except that 40 parts of polyvinyl acetate having an average molecular weight of 20,000 was used. The measurement results are shown in Table 2.

Example 4 In the production of a three-dimensional model by the stereolithography method, as a resin composition, (1) 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 50 parts bis (3,4-epoxycyclohexyl) Methyl) adipate 30 parts (two epoxy groups) Bisphenol A diglycidyl ether 20 parts (2) Bis- [4- (diphenylsulfonio) phenyl]
Sulfidephenylbisdihexafluorophosphate 3 parts (3) Di-2-ethylhexyl phthalate 25 parts The test was conducted according to the method of Example 1 except that 25 parts was used. The measurement results are shown in Table 2.

Example 5 In the production of a three-dimensional model by a stereolithography method, as a resin composition, (1) 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 70 parts 1,4-butanediol diglycidyl Ether 10 parts (2) Bis- [4- (diphenylsulfonio) phenyl]
Sulfide phenyl bisdihexafluoroantimonate 2 parts (3) Di-2-ethylhexyl phthalate 20 parts (4) As a radically polymerizable substance, bisphenol A diglycidyl ether diacrylate 20 parts (acrylic group 2
(5) The test was carried out according to the method of Example 1 except that 1 part of benzophenone was used at the start of energy ray-curable radical polymerization. The measurement results are shown in Table 2.

Example 6 In the production of a three-dimensional model by a stereolithography method, as a resin composition, (1) 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 20 parts bis (3,4-epoxycyclohexyl) Methyl) adipate 10 parts Triethylene glycol divinyl ether 10 parts (2) Bis- [4- (diphenylsulfonio) phenyl]
Sulfide phenyl bisdihexafluoroantimonate 2 parts (3) Polyethylene glycol dimethyl ether having an average molecular weight of 400 30 parts (4) Bisphenol A diglycidyl ether diacrylate 60 parts (5) Benzophenone 1 part except that the method of Example 1 was used. The test was carried out according to. The measurement results are shown in Table 2.

Example 7 In the production of a three-dimensional model by a stereolithography method, as a resin composition, (1) 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 60 parts 1,4-butanediol diglycidyl Ether 10 parts (2) Bis- [4- (diphenylsulfonio) phenyl]
Sulfide phenyl bisdihexafluorophosphate 3 parts (3) Dipropylene glycol diethyl ether 20 parts (4) Bisphenol A diglycidyl ether diacrylate 20 parts Dipentaerythritol hexaacrylate (6 acrylic groups) 10 parts (5) 2-hydroxy The test was carried out in accordance with the method of Example 1 except that 1 part of 2-methyl-1-phenylpropan-1-one was used. The measurement results are shown in Table 2.

Example 8 In the production of a three-dimensional model by a stereolithography method, as a resin composition, (1) 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 50 parts 1,4-butanediol diglycidyl Ether 10 parts (2) Bis- [4- (diphenylsulfonio) phenyl]
Sulfide phenylbisdihexafluorophosphate 3 parts (3) n-octanol 10 parts (4) Diethylene glycol diacrylate 40 parts (5) Benzophenone 1 part A test was conducted according to the method of Example 1 except that 1 part was used. The measurement results are shown in Table 2.

Comparative Example 1 In the production of a three-dimensional model by a stereolithography method, as a cationically polymerizable organic compound as a resin composition, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 75 parts 1,4- Butanediol diglycidyl ether 25 parts According to the method of Example 1 except that bis- [4- (diphenylsulfonio) phenyl] sulfide phenylbisdihexafluoroantimonate 3 parts was used as the energy ray-sensitive cationic polymerization initiator. I did the test. The measurement results are shown in Table 2.

Comparative Example 2 In the production of a three-dimensional model by the stereolithography method, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 70 parts as a cationically polymerizable organic substance as a resin composition 1,4-part Butanediol diglycidyl ether 10 parts As an energy ray sensitive cationic polymerization initiator, bis-
[4- (diphenylsulfonio) phenyl] sulfide phenyl bisdihexafluoroantimonate 2 parts Radical polymerizable organic compound, bisphenol A diglycidyl ether diacrylate 20 parts Energy ray sensitive radical polymerization initiator 1 part benzophenone Other than that, the test was performed according to the method of Example 1. The measurement results are shown in Table 2.

Comparative Example 3 In the production of a three-dimensional model by a stereolithography method, as a cationically polymerizable organic substance as a resin composition, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 60 parts 1,4- Butanediol diglycidyl ether 10 parts Bis-as an energy ray sensitive cationic polymerization initiator
[4- (Diphenylsulfonio) phenyl] sulfide Phenylbisdihexafluorophosphate 3 parts As a radically polymerizable organic compound, bisphenol A diglycidyl ether diacrylate 20 parts Dipentaerythritol hexaacrylate 10 parts As an energy ray sensitive radical polymerization initiator 2-Hydroxy-2-methyl-1-phenylpropan-1-one 1 part A test was conducted according to the method of Example 1 except that 2 parts of n-octanol was used as the thermoplastic material. The measurement results are shown in Table 2.

Comparative Example 4 In the production of a three-dimensional model by a stereolithography method, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate as a resin composition was used as a cationically polymerizable organic substance 50 parts 1,4- Butanediol diglycidyl ether 10 parts Bis-as an energy ray sensitive cationic polymerization initiator
[4- (diphenylsulfonio) phenyl] sulfide phenylbisdihexafluoroantimonate 3 parts As a radically polymerizable organic compound, diethylene glycol diacrylate 40 parts As an energy ray sensitive radical polymerization initiator, benzophenone 1 part As a thermoplastic material n- The test was conducted according to the method of Example 1 except that 65 parts of octanol was used. The measurement results are shown in Table 2.

[0111]

[Table 2]

[0112]

The effect of the present invention is that the resin does not require a post-curing treatment, and when it is embedded in a refractory material as a disappearance prototype of the investment casting method and heated, the prototype causes cracking or distortion of the mold. An object of the present invention is to provide a non-optical three-dimensional modeling resin composition and an investment casting method in which a molded article obtained by this modeling method is used as a disappearing prototype.

[Brief description of drawings]

FIG. 1 is a plan view (a) and a front view (b) of a three-dimensional object created in an example.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08G 59/18 NLE 59/68 NKL C08L 63/00 NJM G03F 7/028 7/038 503 // B29K 105: 24

Claims (6)

[Claims] 1. As essential components, (1) 100 parts by weight of a cationically polymerizable organic compound, (2) 0.05 to 10 parts by weight of an energy ray-sensitive cationic polymerization initiator, and (3) lower than 150 ° C. An optical solid modeling resin composition for producing a disappearing prototype of an investment casting method, which comprises 5 to 50 parts by weight of a thermoplastic material having a melting point and a vapor pressure at 20 ° C. of 1 mmHg or less. 2. As essential components, (1) 100 parts by weight of a cationically polymerizable organic compound, (2) 0.05 to 10 parts by weight of an energy ray-sensitive cationic polymerization initiator,
(3) A thermoplastic material having a melting point lower than 150 ° C. and a vapor pressure at 20 ° C. of 1 mmHg or less, 5 to 50% by weight based on the total amount of (1) and (4), and (4) radical polymerization. Of an organic solid compound of 1 to 150 parts by weight and (5) 0.01 to 15 parts by weight of an energy ray-sensitive radical polymerization initiator for disappearance of investment casting process Composition. 3. Out of 100 parts by weight of the cationically polymerizable organic compound, 50% by weight or more contains 2 epoxy groups in one molecule.
The resin composition for optical three-dimensional modeling for producing a disappearance master in the investment casting method according to claim 1 or 2, which is an epoxy compound having at least one epoxy compound. 4. The radically polymerizable organic compound of 1 to 150 parts by weight, 50% by weight or more is a radically polymerizable compound having two or more (meth) acrylic groups in one molecule. Disappearance of the investment casting method of 1. The optical three-dimensional modeling resin composition for producing a prototype. 5. A method for producing a disappearing prototype of an investment casting method, which comprises irradiating an arbitrary surface of the resin composition according to any one of claims 1 to 4 with an energy ray,
The energy ray-irradiated surface of the resin composition is cured to form a cured layer having a desired thickness, and the above resin composition is further supplied onto the cured layer, and this is similarly cured to cure the above. An optical three-dimensional modeling method characterized in that a three-dimensional three-dimensional object is obtained by repeating a stacking operation to obtain a cured product continuous with layers. 6. An investment casting method, wherein the molded article formed by the optical three-dimensional molding method according to claim 5 is used as a disappearance prototype.