JP2612484B2 - Optical three-dimensional molding resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin composition for optical three-dimensional modeling, and more particularly to an optical composition capable of obtaining a tough cured product having a low viscosity, a small deformation at the time of curing. The present invention relates to a resin composition for three-dimensional modeling.

[Conventional technology]

In recent years, Japanese Patent Application Laid-Open No. Sho 60-247515 has proposed a method of forming a three-dimensional structure having a desired shape by selectively supplying light energy required for curing to a photocurable liquid material.
A similar method or an improvement thereof is described in U.S. Pat.
No. 575,330 (JP-A-62-35966) and JP-A-62-1014.
It is also disclosed in Japanese Patent Publication No. 08 and the like. A typical example of the optical three-dimensional molding method is to selectively irradiate an ultraviolet laser, for example, on a liquid surface of a liquid photocurable resin placed in a container so as to obtain a cured layer having a desired pattern. And then supply a layer of a photocurable resin on the cured layer, and then selectively irradiate light as described above to obtain a laminated layer continuous with the cured layer. This is a method of finally obtaining a desired three-dimensional object by repeating.

This optical three-dimensional modeling method has attracted attention because a target object can be easily obtained in a short time even when the shape of the object to be manufactured is complicated.

Conventionally, photocurable liquid materials used in this optical three-dimensional modeling method include modified polyurethane methacrylate,
Oligoester acrylate, urethane acrylate,
Epoxy acrylate, photosensitive polyimide, amino alkyd and the like are mentioned. (JP-A-60-247515).

[Problems to be solved by the invention]

By the way, in the above-mentioned optical three-dimensional molding method, the viscosity of the resin is low from the viewpoints of handleability, molding speed, molding accuracy, and the like, and a molded article can be formed with high dimensional accuracy with little deformation due to volume shrinkage during curing and the like. Further, it is required that the strength of the obtained molded article is sufficiently high.

However, none of the conventional liquid photocurable resins has these characteristics in a well-balanced manner, and is not satisfactory.

Therefore, an object of the present invention is to provide a resin composition for optical three-dimensional modeling that can obtain a molded article having a low viscosity, a small deformation due to volume shrinkage or the like at the time of curing, and a sufficiently high strength. is there.

[Means for solving the problem]

The present invention, as a solution to the above-mentioned problem, has a difference in apparent specific gravity between the liquid curable resin and the liquid curable resin of 0.2.
The present invention provides a resin composition for optical three-dimensional modeling, comprising:

In the present invention, the optical three-dimensional molding method in which the above resin composition is used is a method of selectively irradiating a liquid curable resin with light to a specific location to supply energy required for curing, and forming a solid having a desired shape. Refers to the method of obtaining a model. The liquid curable resin used here may be a photocurable curable by ultraviolet rays, visible light, or the like, or a thermosetting curable by infrared rays. Therefore, as described above, the light used for irradiation includes ultraviolet light, visible light, infrared light, and the like. The method for selectively irradiating light to a specific portion of the liquid curable resin is not limited. For example, a method of irradiating a specific portion with laser light, a focused light obtained using a lens, a mirror, or the like, There is a method of irradiating the liquid curable resin with light through a mask having a predetermined pattern, thereby irradiating only a specific portion. Further, the specific location to be irradiated with light may be a liquid surface of the liquid curable resin placed in the container, a surface in contact with a side wall or a bottom wall of the container, or a liquid.
In order to irradiate light to the liquid surface of the liquid curable resin or the contact surface with the container wall, the light may be irradiated directly from the outside or through a transparent container wall. ,
For example, irradiation can be performed by a light guide such as an optical fiber.

In this optical three-dimensional molding method, usually, after a desired specific portion is cured, the irradiated position is continuously and stepwise moved from the cured portion to the uncured portion adjacent thereto, thereby curing the cured portion. Can be grown into a desired three-dimensional shape. The irradiation position can be moved in various ways, for example, by moving one or more of the light source, the container and the cured portion, or adding an uncured liquid curable resin to the container.

The above-mentioned optical three-dimensional modeling method includes, for example, Japanese Patent Application Laid-Open No. 60-2475.
No. 15, No. 62-101408, No. 62-35966, "Molding Technology", Vol. 2, No. 9, pp. 72-73, and all the methods included in the above definition are included.

The resin composition of the present invention is used as a liquid curable resin in the above-described optical three-dimensional molding method.

The fine particles contained in the resin composition of the present invention are not particularly limited, for example, a polymer or copolymer of a monomer having a polymerizable ethylenically unsaturated group, polyamide, epoxy resin, phenol resin, benzoguanamine Resin particles made of resin, silicone resin, and the like are included.

The monomer having the polymerizable ethylenically unsaturated group,
A monofunctional monomer having at least one ethylenically unsaturated group, a monofunctional monomer having one ethylenically unsaturated group, a polyfunctional monomer having two or more ethylenically unsaturated groups, or A combination of these may be used.
In particular, when a monofunctional monomer is used as a main component, it is preferable to use a polyfunctional monomer in combination.

Examples of the monofunctional monomer having one ethylenically unsaturated group include isobornyl (meth) acrylate,
Dicyclopentenyl (meth) acrylate, bornyl (meth) acrylate, isobornyloxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2-hydroxyethyl (meth)
Acrylate, 2-hydroxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, butoxyethyl (meth) acrylate, ethyldiethylene glycol (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclo Pentagen (meth) acrylate, polyethylene glycol (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-
Monofunctional (meth) acrylic monomers such as amino-3,7-dimethyloctyl (meth) acrylate, acrylamide, isobutoxymethylacrylamide, diacetoneacrylamide, N, N-dimethylacrylamide; or N-vinylpyrrolidone; N-vinylcaprolactam,
Examples thereof include vinyl phenol, vinyl acetate, vinyl ether, styrene, acrylonitrile, ethylene, and propylene.

Examples of the polyfunctional monomer having two or more ethylenically unsaturated groups include a polyfunctional (meth) acrylic monomer and divinylbenzene. The polyfunctional (meth) acrylic monomer has at least two (meth) acryloyl groups and is, for example, trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate. (Meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentenyl di Examples thereof include (meth) acrylate, polyester di (meth) acrylate, both-terminal (meth) acrylic acid adduct of bisphenol A glycidyl ether, and pentaerythritol tetra (meth) acrylate.

The resin particles composed of the various raw materials described above can be produced by a known method utilizing a suspension polymerization method or an emulsion polymerization method. These resin particles can also be obtained as commercial products, for example, Nippon Shokubai Chemical Co., Ltd. Eposter S, Soken Chemical Co. MP-1000, Toshiba Silicone Co. XC99-
501, Fine Pearl 3000SP manufactured by Sumitomo Chemical, SP manufactured by Toray
-500, EP-13, Bell Pearl manufactured by Kanebo, Lubron L-5 manufactured by Daikin, Flowbeads LE-1080, Flowbeads CL-2080, Flowbeads EA-209, Flowsen UF, etc. manufactured by Seikagaku Co., Ltd. be able to.

The fine particles composed of these polymers or copolymers are 1
Species can be used alone or in combination of two or more. The particle shape is not particularly limited.

Furthermore, as the fine particles in the present invention, hollow particles made of an inorganic material can also be used.

In the composition of the present invention, the particle size of the fine particles used is usually 0.1 to 50 μm, preferably 0.5 to 35 μm, particularly preferably 1 to 25 μm, and the apparent specific gravity is usually 0.9 to
1.2. If the particle size is too small, the viscosity of the obtained optical three-dimensional modeling resin composition increases, and the productivity and modeling accuracy of the three-dimensional modeled product are inferior. In some cases, the surface may decrease or a sufficiently smooth surface may not be obtained.

In the composition of the present invention, the difference in apparent specific gravity between the microparticles and the liquid curable resin is preferably as small as possible from the viewpoint of storage stability of the composition, less than 0.2, preferably less than 0.1, and particularly preferably 0.05. Is less than. If the difference in apparent specific gravity exceeds 0.1, the fine particles and the liquid curable resin are separated during storage.

Furthermore, when it is desired to obtain a transparent three-dimensional structure using the composition of the present invention, the difference between the refractive index of the fine particles to be used and the refractive index of the liquid curable resin after curing is minimized. Is preferred. For example, the absolute value of the difference between the two refractive indexes may be set to 0.2 or less.

The content of the fine particles in the composition of the present invention is usually 5 to 45% by weight, preferably 8 to 40% by weight, particularly preferably 10 to 35% by weight. If the content of the fine particles is too small, the effect of the addition of the fine particles cannot be sufficiently obtained, and if the content is too large, the viscosity of the obtained composition increases, the handleability of the composition, the molding speed of the three-dimensional molded object , The molding accuracy and the like may be deteriorated.

The liquid curable resin used in the composition of the present invention is light,
There is no particular limitation as long as it has a property of being cured by heat or the like, and examples thereof include those composed of the following components.

(A) an oligomer having two or more (meth) acryloyl groups, (B) (B-1) a monofunctional monomer having an ethylenically unsaturated group, and / or (B-2) an ethylenically unsaturated group. (C) Polymerization initiator The oligomer having two or more (meth) acryloyl groups, which is the component (A) of the specific examples of the liquid curable resin described above, includes, for example, an ester skeleton, a urethane It is an oligomer having at least one skeleton selected from a skeleton and a skeleton having an epoxy ring-opening structure, preferably an urethane skeleton. Specifically, polyol compounds such as polyether polyol, polyester polyol, polycaprolactone polyol, and polycarbonate polyol, preferably a polyol compound having about 2 to 5 hydroxyl groups in one molecule on average, a diisocyanate compound and (meth) Urethane (meth) acrylate oligomers obtained by reacting with an acryloyl group-containing compound; ester (meth) acrylate oligomers obtained by an esterification reaction of a similar polyol compound with a (meth) acryloyl group-containing compound; An epoxy (meth) acrylate compound obtained by an addition reaction between an epoxy compound and a compound having a (meth) acryloyl group.

Here, examples of the polyether polyol include polyoxyethylene diol, polyoxypropylene diol, and polyoxytetramethylene diol.

Examples of the polyester polyol include (poly) ethylene glycol, (poly) propylene glycol,
Dihydric alcohols such as (poly) tetramethylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, and phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, Those obtained by reacting with a dibasic acid such as sebacic acid may be mentioned.

As borica prolactone polyol, for example, ε-
Examples include those obtained by reacting caprolactone with a divalent diol such as (poly) ethylene glycol, (poly) tetramethylene glycol, 1,6-hexanediol, neopentyl glycol, and 1,4-butanediol. .

Examples of the polycarbonate polyol include commercially available products such as DN-980, DN-981, DN-982, and DN-983 (all manufactured by Nippon Polyurethane Co., Ltd.) and PC-8000 (US PPG).
And the like).

Preferred among these polyol compounds are polyester diols.

Examples of the diisocyanate compound to be reacted with these polyol compounds include, for example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, 1,5-naphthalene diisocyanate, p- Phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylene diisocyanate, 4,4'-biphenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate , Dicyclohexylmethane diisocyanate, methylene bis (4-cyclohexyl isocyanate), hydrogenated diphenylmethane diisocyanate, 2,2,4
-Trimethylhexamethylene diisocyanate, bis (2-isocyanatoethyl) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate and the like.

Examples of the compound having a (meth) acryloyl group to be reacted with a polyol compound include, for example, a (meth) acrylic compound having a hydroxyl group. Specific examples of the (meth) acrylic compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate.
Hydroxypropyl (meth) acrylate, 2-hydroxyoctyl (meth) acrylate, pentaerythritol (meth) acrylate, glycerin di (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, 1,4-butanediol mono (meth) A) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropanedi (meth) acrylate, trimethylolethanedi (meth) acrylate And glycidyl group-containing compounds such as alkyl glycidyl ethers, aryl glycidyl ethers and glycidyl acrylates and (meth) acrylic acid. That compounds can be mentioned.

Examples of the epoxy compound include glycidyl ether obtained by reacting bisphenol A or its alkylene oxide adduct with epichlorohydrin; glycidyl ether obtained by reacting hydrogenated bisphenol A or its alkylene oxide adduct with epichlorohydrin, phenol novolak Polyglycidyl ether, diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, diglycidyl ether of polyethylene glycol; propylene glycol, Addition of alkylene oxides such as ethylene oxide and propylene oxide to aliphatic dihydric alcohols such as glycerin Diglycidyl ether of polyether diol obtained by the above method; diglycidyl ester of aliphatic long-chain dibasic acid; phenol, butyl phenol, cresol or monoglycidyl ether of polyether alcohol obtained by adding alkylene oxide thereto; Glycidyl phthalate; diglycidyl phthalate; glycidyl acrylate, polyglycidyl acrylate; 3,4-epoxycyclohexanecarboxylate, and the like.

Further, commercially available products can also be used as the component (A), for example, Ebecry1204, Ebecry1205, and Ebecry1 manufactured by UCB.
210, Ebecry1220, Ebecry1240, Ebecry1254, Ebecry126
4, Ebecry1265, Ebecry1270, Ebecry1284, Ebecry128
5, Ebecry1600, Ebecry1601, Ebecry1604, Ebecry160
5, Ebecry1608, Ebecry1616, Ebecry1608, Ebecry1260
8, Ebecry1860; ARCO CHEMLINK3000, CHEMLINK5000,
CHEMLINK9503, CHEMLINK9504, CHEMLINK9505; Alonix M-6100, Aronix M-625 manufactured by Toa Gosei Chemical Co., Ltd.
0, Aronix M-6300, Aronix M-6500, Aronix M-8030, Aronix M-8060; UVITHANE893 manufactured by Morton Thiokol; EPON1001, EPON manufactured by Shell
828 and the like.

The content of the component (A) in the composition is usually 5
3535% by weight, preferably 10-35% by weight, more preferably 10-30% by weight. If the content of the component (A) is too small, the resulting composition tends to cause an increase in volume shrinkage at the time of curing, a decrease in the curing speed, a deterioration in the mechanical properties of the cured product, and the like, and the content is too large. In some cases, the viscosity of the resulting composition may increase, the production speed of the three-dimensional molded article may decrease, or the surface smoothness of the cured product may be impaired.

As the monofunctional monomer having an ethylenically unsaturated group (B-1) among the components (B), the monofunctional monomer having one ethylenically unsaturated group exemplified above as a raw material for the fine particles is used. Among these, preferred are monofunctional (meth) acrylic monomers, vinylpyrrolidone and vinylcaprolactam.

When adjusting the refractive index of the composition, (B-
1) As a component, a compound having a high refractive index, for example, the following formula (I): Wherein R ¹ and R ² may be the same or different and are a hydrogen atom or a methyl group, and R ³ is a hydroxyl group-substituted or unsubstituted linear or branched alkylene having 2 to 6 carbon atoms. X is a halogen atom, and m is 0 to
Is an integer of 6, and n is an integer of 1 to 5].

Specific examples of the compound represented by the above formula (I) include tribromophenyl (meth) acrylate, tetrabromophenyl (meth) acrylate, tetrachlorophenyl (meth) acrylate, and pentabromophenyl (meth)
Acrylate, pentachlorophenyl (meth) acrylate, 2-trichlorophenoxyethyl (meth) acrylate, 2-tribromophenoxyethyl (meth) acrylate, 2-tetrachlorophenoxyethyl (meth)
Acrylate and 2-tetrabromophenoxyethyl (meth) acrylate can be exemplified.

As the (B-2) polyfunctional monomer having an ethylenically unsaturated group in the component (B), the polyfunctional monomer having two or more ethylenically unsaturated groups exemplified above as the raw material of the microparticles may be used. Monomers and other multifunctional monomers having an ethylenically unsaturated group can be exemplified, and among these, polyfunctional (meth) acrylic monomers are preferable.

These components (B) are usually contained in the composition in an amount of 15 to 75% by weight, preferably 20 to 75% by weight, particularly preferably 30 to 75% by weight.
% By weight. If this content is too large, the resulting composition tends to have an increased cure shrinkage and a decreased cure speed.

The type of the polymerization initiator of the component (C) is not particularly limited, and various photopolymerization initiators and thermal polymerization initiators can be used, and the following compounds can be exemplified.

Photopolymerization initiator: acetophenone, benzophenone, xanthone, fluorenone, anthraquinone, carbazole, 4-chlorobenzophenone, 3,3-dimethyl-4-
Methoxybenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin ethyl ether, benzoin propyl ether, acetophenone diethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-
2-methylpropan-1-one, 2-methyl-1- (4-
(Methylthio) phenyl) -2-morpholino-propan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzyldimethyl ketal, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, thioxanthone compound, 3,3 ′, 4, 4'-tetra (t-butylperoxycarbonyl) benzophenone (BTTB), and
A combination of BTTB with xanthene, thioxanthene, coumarin, ketocoumarin and other dye sensitizers such as camphorquinone and fluorescein.

Thermal polymerization initiator: benzoin peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 2,4-
Dichlorobenzoyl peroxide, t-butyl peroxide, azobisisobutyronitrile.

These components (C) may be used alone or in combination of two or more. In the case of a photopolymerization initiator, if necessary, a sensitizer for effectively utilizing light from a light source, an amine compound, etc. May be used in combination.

The content of the component (C) in the composition is usually 0.03 to 10% by weight, preferably 0.1 to 8% by weight. If the content of the component (C) is too small, the curability of the obtained composition tends to decrease, and if it is too large, the mechanical strength of the obtained cured product tends to decrease.

The composition of the present invention, if necessary, a leveling agent,
Surfactants, organosilicon compounds, inorganic fillers, pigments, dyes and the like may be blended.

The composition of the present invention is obtained by mixing the above-mentioned fine particles and the liquid curable resin, or adding other components as necessary, but the method of mixing these components is not particularly limited.

The viscosity of the composition of the present invention is usually 100 to 2000 cP.

The light used when obtaining a molded article by an optical three-dimensional molding method using the composition of the present invention is selected depending on whether the composition is photocurable or thermosetting, UV light,
Visible light, infrared light and the like are used, but ultraviolet light is preferably used.

The following are examples of more specific embodiments of the optical three-dimensional molding method using the composition of the present invention.

After the first cured layer is formed, the uncured composition for the next cured layer is additionally supplied on the obtained first cured layer,
A method of repeating the operation of irradiating light to form the next cured layer.

Submerging the bottom plate in the composition by the depth of the first hardened layer,
After the first cured layer is formed, the bottom plate is further submerged by a further depth to allow one layer of the uncured composition to flow onto the first cured layer, and further irradiate light. A method of repeating the operation of forming the next cured layer.

A box having a transparent bottom plate is submerged in the composition contained in the container, and the composition layer formed in the gap between the bottom plate and the bottom surface of the container is made to have the same thickness as the first cured layer. Irradiating the composition layer with light through a transparent bottom plate of a box,
After forming a cured layer, the box is raised to allow the composition to flow into the gap between the first cured layer and the transparent bottom plate of the box,
A method of repeating the operation of forming the next cured layer by irradiating light in the same manner.

The plate is submerged in a composition placed in a container having a transparent bottom, and the composition layer formed in the gap between the plate and the bottom surface of the container is made to have the same thickness as the first cured layer. Irradiating the composition layer with light through a transparent bottom of a container to form a first cured layer, and then raising the plate by one thickness to obtain one layer of the uncured composition. In the gap between the first hardened layer and the plate, and then irradiating with light in the same manner as described above to form a next hardened layer.

The three-dimensional structure formed by the above methods (1) to (5) is removed from the container used for the reaction, and after removing the unreacted composition remaining on the surface of the three-dimensional structure, washing is performed as necessary. As a cleaning agent used for cleaning, for example, an organic solvent typified by alcohols such as isopropyl alcohol or a resin having a low-viscosity thermosetting or photocuring viscosity of, for example, 200 cP or less can be used. When it is desired to impart transparency to a three-dimensional structure, it is preferable to use the low-viscosity thermosetting or photocurable resin for cleaning. In this case, it is necessary to perform post-curing by heat or light after cleaning, depending on the type of resin used for cleaning. This post cure not only cures the uncured resin on the surface, but also cures the unreacted composition that may remain inside the three-dimensional structure, so even when washed with an organic solvent. It is preferable to carry out.

〔Example〕

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Example 1 A reaction vessel equipped with a stirrer was charged with 180 g of a polyester-based urethane acrylate oligomer (Ubisan 893 manufactured by Morton Thiokol Co., Ltd.), 60 g of trimethylolpropane triacrylate, and 60 g of vinylpyrrolidone. Heating for hours gave a mixture. (Hereinafter referred to as “mixture I”) Next, in a sealable container having an inner volume of 250 ml, the difference in apparent specific gravity between the above-mentioned mixture I (36.4 g), isobornyl acrylate (48.6 g) and the polyester-based urethane acrylate oligomer was 0.1. 15 g of copolymer particles having an average particle size of 3 μm and having a molar ratio of divinylbenzene to styrene of 80:20, and a photopolymerization initiator (Irgacure 184 manufactured by Ciba Geigy KK) 6.0
g and 80 ml of stainless steel balls having a particle diameter of 3 mm were mixed and mixed for 1.5 hours using a paint shaker. The resulting mixture was filtered through a 200-mesh nylon filter to remove stainless steel balls, to obtain a resin composition for optical three-dimensional modeling.
This was designated as “composition A”.

The viscosity of the obtained composition A was measured, and the shrinkage, gel content and Young's modulus of the cured product were measured according to the following methods, and the appearance of the cured product was observed. Table 1 shows the results.
Shown in

Shrinkage rate of cured product Focused He-Cd laser beam (output 200mW, wavelength 3250
I) is 30 mm x 30 from the direction perpendicular to the surface of the composition.
Irradiation was performed so that a rectangle of mm × 0.4 mm was obtained. Density of cured composition (D ₁ ) and composition before curing (D ₂ )
Was measured, and the shrinkage of the cured product was calculated from the following equation.

Shrinkage (%) = 100 × [(1 / D ₂ ) − (1 / D ₁ )] / (1 / D ₂ ) Gel content of cured product Composition under the same conditions as measurement of cured product shrinkage Was cured, and the weight of the obtained cured product was measured at 23 ° C., and then immersed in 100 ml of methyl ethyl ketone at 23 ° C. for 1 hour. Thereafter, the cured product was taken out, dried at 70 ° C. for 1 hour under normal pressure, weighed at 23 ° C., and the gel content was calculated.

Young's modulus of cured product Focused He-Cd laser beam (output 20mW, wavelength 3250mm)
From a perpendicular to the surface of the composition, 50 mm × 3 mm × 0.4 mm
Irradiation was performed to obtain a rectangle. 23 cured composition
The condition was adjusted at 50 ° C. and a relative humidity of 50% for 24 hours to obtain a test piece.
The Young's modulus of this test piece was measured at a temperature of 23 using a tensile tester.
The measurement was performed at a temperature of 50 ° C. and a relative humidity of 50% under the conditions of a tensile speed of 10 mm / min and a distance between marked lines of 15 mm.

Appearance of cured product The composition was cured under the same conditions as the measurement of the shrinkage of the cured product, and the resulting cured product was a UV-curable cleaning resin having a viscosity of 80 cP [KAYARAD DPCA-120 manufactured by Nippon Kayaku Co., Ltd.] 20 parts by weight, vinylpyrrolidone 74 parts by weight, a photopolymerization initiator: a mixture of Irgacure 184 (manufactured by Ciba Geigy Co., Ltd.) 4 parts by weight and a photopolymerization initiator: benzophenone 2 parts by weight). It was immersed and the surface was washed. Next, using a 300 kW high-pressure mercury lamp, 3 cm from a distance of 20 cm
The composition after washing was irradiated with ultraviolet rays for 0 seconds to cure the washing resin, and the surface of the obtained cured product was visually observed.

Example 2 Instead of the copolymer particles of divinylbenzene and styrene having an average particle diameter of 3 μm, a difference in apparent specific gravity with the polyester-based urethane acrylate oligomer was 0.07, and the particles were made of polydivinylbenzene having an average particle diameter of 0.3 μm. Except for using the particles, a resin composition for optical three-dimensional modeling was obtained in the same manner as in Example 1, and was referred to as “composition B”.

The viscosity of the obtained composition B was measured, and the shrinkage, gel content and Young's modulus of the cured product were measured, and the appearance of the cured product was observed. The results are shown in Table 1.

Example 3 Instead of copolymer particles of divinylbenzene and styrene having an average particle diameter of 3 μm, low-density polyethylene particles having an apparent specific gravity difference of 0.09 from the polyester-based urethane acrylate oligomer and an average particle diameter of 5 μm were used. A resin composition for optical three-dimensional modeling was obtained in the same manner as in Example 1 except that the above-mentioned procedure was performed, and was referred to as “composition C”.

The viscosity of the obtained composition C was measured, and the shrinkage ratio, gel content and Young's modulus of the cured product were measured, and the appearance of the cured product was observed. The results are shown in Table 1.

Example 4 Instead of using copolymer particles of divinylbenzene and styrene having an average particle size of 3 μm, the difference in apparent specific gravity from the polyester-based urethane acrylate oligomer was 0.13, and polyamide particles having an average particle size of 7 μm were used. In the same manner as in Example 1, a resin composition for optical three-dimensional modeling was obtained, and was referred to as “composition D”.

The viscosity of the obtained composition D was measured, and the shrinkage, gel content and Young's modulus of the cured product were measured, and the appearance of the cured product was observed. The results are shown in Table 1.

Comparative Example 1 In a reaction vessel equipped with a stirrer, 42.9 g of the mixture I obtained in Example 1, 57.1 g of isobornyl acrylate, and a photopolymerization initiator (Irgacure 184 manufactured by Ciba Geigy KK) 6.0
g, and heated at 50 ° C. for 1 hour with stirring to obtain a resin composition for optical three-dimensional printing, which was designated as “composition E”. The viscosity of this composition E was measured, and the shrinkage, gel content, and Young of the cured product were measured in the same manner as in Example 1.
The appearance of the cured product was observed. The results are shown in Table 1.

(Effect of the Invention) The optical three-dimensional modeling resin composition of the present invention has a low viscosity,
In addition, since the volumetric shrinkage at the time of curing is small, it is possible to obtain a molded article with high molding accuracy with high productivity by the optical three-dimensional molding method. Furthermore, after curing, a shaped article having sufficiently high strength can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsutoshi Igarashi 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (72) Inventor John Jay Crazysky 60090, Wheeling, Illinois, United States , Valley Stream Drive 932 (72) Inventor Robert E. Ansell, Illinois, United States 60194, Hoffman Estates, Coldwell Lane 1440 (72) Inventor Edward J. Murphy, United States, Illinois 60005, Arlington Heights, S. Mitchell 742 (72) Inventor John T. Vandeberg, United States, 60010, Illinois, Burlington, AW Oakwood Dora 415 (56) References JP-A-60-247515 (JP, A) JP-A-62-101408 (JP, A) JP-A-62-35966 (JP, A) JP-A-62-43412 (JP, A) )

Claims (1)

(57) [Claims] 1. An optical three-dimensional molding resin composition comprising a liquid curable resin and fine particles having an apparent difference in specific gravity between the liquid curable resin and the liquid curable resin of less than 0.2.