JP5288758B2 - Photocurable composition for stereolithography, metal molding and method for producing the same - Google Patents

Description

  The present invention relates to a photocurable composition for producing a metal model using an optical modeling method, a three-dimensional model manufactured using the composition, and a metal model formed by firing the three-dimensional model. Related to things.

It has hitherto been known to manufacture a modeled object having a complicated three-dimensional shape using an optical modeling method.
As the stereolithography method, light is applied to the thin layer liquid surface of the photocurable resin liquid to form a cured product (cross-sectional cured layer) having a desired pattern cross section, and then, 1 layer of photocurable resin liquid is supplied on top, irradiated with light to further form a cross-section hardened layer, and thereafter, by repeating this operation, a plurality of cross-section hardened layers are laminated and integrated. A method of modeling a three-dimensionally shaped object having the following shape is representative.
In addition, a method for manufacturing a ceramic model using an optical modeling method is also known. Specifically, by mixing ceramic fine particles such as alumina and silica in a photocurable resin liquid, and manufacturing a three-dimensional object by the optical modeling method, further firing the three-dimensional object, a complicated three-dimensional shape A ceramic shaped article having sapphire can be produced (Patent Document 1).

On the other hand, a method of manufacturing a metal shaped article using metal particles is known.
For example, depositing a plurality of metal or metal alloy particles and a particle mixture containing peroxide in a limited area and selecting a binder system as a predetermined area of the particle mixture to form a green part The binder system includes a water-soluble monofunctional acrylate monomer, a water-soluble bifunctional acrylate monomer, an amine, and water. A method of manufacturing a three-dimensional metal object has been proposed (Patent Document 2).
JP 2006-348214 A JP 2005-120475 A

In the technique described in Patent Document 1, the number average particle diameter of the inorganic fine particles used for optical modeling is limited to 5 to 300 nm. If inorganic fine particles having a particle size larger than this are used, it becomes difficult to impart sufficient thixotropy to the liquid composition containing the inorganic fine particles, and the coating property at the time of optical modeling is inferior. It is said that the accuracy of will decrease.
In addition, the technique described in Patent Document 2 requires an operation of ejecting a binder system by an inkjet method to a predetermined area of a particle mixture containing a plurality of metal or metal alloy particles and a peroxide. Therefore, the technique described in Patent Document 2 cannot be applied to a method that does not use the inkjet method.
On the other hand, if the metal modeling thing which has electroconductivity can be formed using an optical modeling method, not only the prototype of a machine part but the field of an optical modeling method also in fields, such as MEMS (micro electro mechanical systems), for example. The application range can be expanded.
Here, the MEMS is a device in which various fine structures such as a mechanical structure and an electronic circuit including movable parts such as actuators and sensors are integrated on a substrate. MEMS are manufactured using various microfabrication technologies such as semiconductor manufacturing technology and laser processing technology, and can realize extremely small and high-performance devices compared to conventional technologies. In recent years, it has attracted attention in various fields such as automobiles.
Then, this invention provides the photocurable composition which has the favorable electroconductivity and can manufacture easily the metal modeling thing which has a small and highly accurate solid shape which can be used for MEMS etc. With the goal.

As a result of investigations to solve the above problems, the present inventors have found that (A) a monomer having three or more ethylenically unsaturated groups, (B) a photopolymerization initiator, and (C) dynamic light scattering. the fine metal particles a number-average particle diameter of 0.5~3μm by law, seen including in particular blending ratio, and the content of the monomer having 5 or more ethylenically unsaturated groups in component (a) 50 It has been found that the above-mentioned object of the present invention can be achieved with a photocurable resin composition having a mass% or more, and the present invention has been completed.

That is, the present invention provides the following [1] to [10].
[1] A photocurable composition for producing a three-dimensional structure using an optical modeling method, wherein (A) a monomer having three or more ethylenically unsaturated groups, (B) a photopolymerization initiator, and (C) metal fine particles having a number average particle size of 0.5 to 3 μm by dynamic light scattering, and (A) the content ratio of the monomer having 5 or more ethylenically unsaturated groups in the component is 50 and% by mass or more, the blending ratio of the component (C) is a 85 to 95 wt% of the total amount of the photocurable composition as 100 mass%, and the formulation of each of the components (a) and component (B) The proportion is 70 to 95% by mass and 0.01 to 10% by mass with respect to 100% by mass of the total amount of the photocurable composition excluding the component (C). object.
[2] The monomer having 5 or more ethylenically unsaturated groups in the component (A) is selected from the group consisting of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate. The photocurable composition according to [1], which is a seed or more .
[3] The component (C) contains one or more metals selected from the group consisting of copper, iron, nickel, cobalt, aluminum, gold, silver, tin, platinum, zinc, palladium, iridium, titanium, and tantalum. The photocurable composition as described in [1] or [2] above.
[4] The photocurable composition according to any one of [1] to [3], which is for optical layered modeling.
[5] A three-dimensional structure formed of a cured product of the photocurable composition according to any one of [1] to [4].
[6] After irradiating the photocurable composition according to any one of [1] to [4] with light to form a cured layer of the composition, the composition is formed on the cured layer. Is again applied, and irradiated with light to further form a cured layer of the composition, and thereafter, by repeating this, a three-dimensional structure that forms a three-dimensional structure formed by laminating and integrating a plurality of cured layers Manufacturing method.
[7] The method for producing a three-dimensional structure according to [6], wherein the thickness of the hardened layer is 50 to 200 μm.
[8] A metal model including a single metal, which is obtained by firing the three-dimensional model according to [5].
[9] The photocurable composition according to any one of the above [1] to [4] is cured by an optical modeling method to obtain a three-dimensional model, and the three-dimensional model is fired. The manufacturing method of the metal molded article including the baking process of obtaining a metal molded article.
[10] The method for producing a metal shaped article according to the above [9], wherein the firing step is heating at 400 ° C. or higher in a reducing atmosphere after heating at 400 ° C. or higher in an oxidizing atmosphere.

Since the photocurable composition of the present invention has a suitable light transmittance, it can suppress light scattering and can be laminated at a curing depth suitable for an optical modeling method. Since it has such an excellent multi-layer stackability, the three-dimensional structure having a desired small and high-precision three-dimensional shape without forming the three-dimensional structure and without causing the cured layers to peel apart from each other. Can be easily obtained.
Further, by firing this three-dimensional structure, a small and high-precision metal structure that can be used for semiconductor processes such as a metal barrier layer and a plating seed layer, MEMS, and the like can be manufactured.
Furthermore, the electroconductivity excellent in the metal modeling thing can be given by baking on specific conditions at the time of manufacture of a metal modeling thing.

First, the photocurable composition for optical modeling of the present invention will be described.
The composition of the present invention has (A) a monomer having three or more ethylenically unsaturated groups, (B) a photopolymerization initiator, and (C) a number average particle diameter determined by a dynamic light scattering method of 0.5 to 3 μm. It contains metal fine particles.
Hereinafter, each component will be described. In the present specification, the “resin component” refers to all components of the photocurable composition excluding the component (C) (metal fine particles).

[(A) component]
The component (A) used in the photocurable composition of the present invention is a monomer having 3 or more ethylenically unsaturated groups. Examples of the monomer having 3 or more ethylenically unsaturated groups (C = C) include (meth) acrylic monomers having 3 or more ethylenically unsaturated groups. In the present specification, having three or more ethylenically unsaturated groups may be referred to as “trifunctional or more”.

  Examples of the monomer that can be suitably used as the component (A) include tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, caprolactone-modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, and trimethylolpropane. Tri (meth) acrylate, ethylene oxide (hereinafter referred to as “EO”) modified trimethylolpropane tri (meth) acrylate (hereinafter also referred to as “ethoxylated trimethylolpropane tri (meth) acrylate”), propylene oxide (hereinafter referred to as “PO”) Modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, dipe Taerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol penta (meth) acrylate, ditrimethylol Examples include propanetetra (meth) acrylate and triacryloyloxyethyl phosphate.

  Of these, trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, triacryloyloxyethyl phosphate, dipentaerythritol hexa ( Particularly preferred are (meth) acrylate, dipentaerythritol penta (meth) acrylate, and ditrimethylolpropane tetra (meth) acrylate.

Examples of commercially available monomers include, for example, Aronix M305, M309, M310, M315, M320, M350, M360, M408 (above, manufactured by Toagosei Co., Ltd., Biscoat # 295, # 300, # 360, GPT, 3PA, # 400 (above, Osaka Organic Chemical Industry Co., Ltd.), NK Ester TMPT, A-TMPT, A-TMM-3, A-TMM-3L, A-TMMT (above, Shin-Nakamura Chemical Co., Ltd.), Light acrylate TMP-A, TMP-6EO-3A, PE-3A, PE-4A, DPE-6A (above, manufactured by Kyoeisha Chemical Co., Ltd., KAYARAD PET-30, GPO-303, TMPTA, TPA-320, DPHA, D-310, DPCA-20, DPCA-60 (above, Nippon Kayaku Co., Ltd. product) etc. are mentioned.
Monomers having three or more ethylenically unsaturated groups can be used alone or in combination of two or more.

The blending ratio of the component (A) is 70 to 95% by mass, preferably 80 to 95% by mass, more preferably 85 to 95% by mass, with the resin component being 100% by mass. When the blending ratio is less than 70% by mass, the photocurability of the composition is lowered, the mechanical strength of the three-dimensional model is lowered, or the curing depth suitable for the optical modeling method is not obtained, and the composition It becomes difficult to stack the objects in multiple stages, and a molded object having a desired three-dimensional shape may not be obtained. On the other hand, when the blending ratio exceeds 95% by mass, not only the handleability of the composition is deteriorated, but also the mechanical properties (mechanical strength) of the three-dimensional structure may be lowered.
Moreover, (A) component improves the photocurability of a composition, and the monomer (tetrafunctional or more monomer) which has four or more ethylenically unsaturated groups from a viewpoint of obtaining the hardened | cured material which has a desired three-dimensional shape. It is preferable to contain. Among tetrafunctional or higher functional monomers, pentafunctional or higher functional monomers are preferable, and hexafunctional or higher functional monomers are more preferable.
(A) content of the monomer of 5 or higher functional component (preferably 6 or more functional groups) is preferably 50 mass% or more, preferably 70 mass% or more.

[Component (B)]
(B) component used for the photocurable composition for optical shaping | molding of this invention is a photoinitiator. (B) The photopolymerization initiator is preferably a radical photopolymerization initiator. A radical photopolymerization initiator is a compound that is decomposed by receiving energy rays such as light and initiates a radical polymerization reaction by generated radicals.

Specific examples of the component (B) include, for example, acetophenone, acetophenone benzyl ketal, anthraquinone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4-chlorobenzophenone. 4,4′-diaminobenzophenone, 1,1-dimethoxydeoxybenzoin, 3,3′-dimethyl-4-methoxybenzophenone, thioxanthone compound, 2-methyl-1- [4- (methylthio) phenyl] -2- Morpholino-propan-2-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-tri-methylpentylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy -2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde, benzoin ethyl ether, benzoin propyl ether, benzophenone, 3-methylacetophenone, 3,3 ′, 4,4′-tetra (t-butyl Peroxycarbonyl) benzophenone (BTTB) and combinations of BTTB with xanthene, thioxanthene, coumarin, ketocoumarin and other dye sensitizers.
Of these, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1- Particularly preferred are ON, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, and the like.
These compounds are used individually by 1 type or in combination of 2 or more types.

When the composition of the present invention is used in an optical modeling method such as an optical layered modeling method, usually a curing light having a wavelength in the near ultraviolet region of about 405 nm is used, and therefore a photopolymerization initiator having absorption in this wavelength region is used. Preferably used.
Specifically, a photopolymerization initiator having a molar extinction coefficient at 405 nm of 500 (L / mol · cm) or more is preferable. Among the above examples, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (molar extinction coefficient at 405 nm: 619 L / mol · cm), bis (2,6-dimethoxybenzoyl) -2,4 , 4-trimethylpentylphosphine oxide (molar extinction coefficient at 405 nm: 575 L / mol · cm) and the like are preferable.

  The blending ratio of the component (B) is 0.01 to 10% by mass, preferably 0.1 to 8% by mass, more preferably 1 to 5% by mass, based on 100% by mass of the resin component. When the blending ratio is less than 0.01% by mass, the radical polymerization reaction rate (curing rate) of the composition is small, so that it may take time to form a three-dimensional structure or the resolution may be lowered. When the said mixture ratio exceeds 10 mass%, an excessive amount of (B) component may reduce the hardening characteristic of a composition, or may reduce the intensity | strength of a three-dimensional molded item.

[Component (C)]
(C) component used for the photocurable composition of this invention is a metal microparticle.
The number average particle diameter of the component (C) (metal fine particles) is 0.5 to 3 μm, preferably 0.5 to 2 μm. When the number average particle size is less than 0.5 μm, the conductivity of the metal shaped article becomes insufficient. When the number average particle size exceeds 3 μm, the multi-layer stackability is inferior, and it is difficult to produce a small three-dimensional structure that can be used for MEMS or the like.
The number average particle diameter is a value measured by a dynamic light scattering method.

As the fine metal particles used as the component (C), one or more selected from the group consisting of copper, iron, nickel, cobalt, aluminum, gold, silver, tin, platinum, zinc, palladium, iridium, titanium, and tantalum. Examples include metal fine particles containing metal. From the viewpoint of usefulness, the metal fine particles are preferably metal fine particles containing one or more metals selected from copper, iron, nickel, cobalt, and aluminum, and more preferably metal fine particles containing copper.
The metal fine particles may be composed of a simple metal (consisting of only one or more metal elements), or may be composed of a metal compound such as a metal oxide.
The oxidation number of the metal oxide is preferably 2 or less. A metal oxide having an oxidation number of 3 (for example, alumina) is not preferable because it is difficult to produce a three-dimensional structure mainly composed of a single metal.
As the component (C), it is preferable from the viewpoint of obtaining good conductivity to use metal fine particles composed of only a metal simple substance, or metal fine particles composed of a metal simple substance of 50 mass% or more and a metal oxide of 50 mass% or less.

Preferred examples of the component (C) include single metal fine particles of a single metal composed of one metal selected from the group consisting of copper, iron, nickel, cobalt, and aluminum, and two or more of the above metals. Examples thereof include fine particles of an alloy of simple metals, and a mixture of these fine particles of simple metals and their oxides (however, those containing an oxide in a blending amount of 50% by mass or less).
A particularly preferable example of the component (C) is, from the viewpoint of electrical conductivity of the metal shaped article, simple copper fine particles, or a mixture of simple copper fine particles and copper oxide fine particles (however, a blend of 50% by mass or less) Containing oxides in an amount).

The blending ratio of the component (C) is 85 to 95% by mass , particularly preferably 85 to 93% by mass , based on 100% by mass of the total amount of the photocurable composition of the present invention. If the said mixture ratio is less than 85 mass%, the intensity | strength and electroconductivity of a metal molded article may become inadequate. On the other hand, when the blending ratio exceeds 95% by mass, not only is it difficult to mix the composition uniformly, but the blending ratio of the component (A) is small, so that the bonding force between the metal fine particles is small. Therefore, various physical properties (mechanical properties, multi-layered laminate properties, etc.) of a shaped product formed by photocuring may be inferior.

[Optional ingredients]
The photocurable composition of the present invention contains a monomer having one ethylenically unsaturated group (hereinafter also referred to as a monofunctional monomer) or an ethylenically unsaturated group within a range that does not impair the purpose and effect of the present invention. A monomer having two (hereinafter also referred to as a bifunctional monomer) can be blended.
Examples of the monofunctional monomer include nitrogen-containing vinyl compounds such as N-vinylcaprolactam and N-vinylpyrrolidone, (meth) acrylamide, (meth) acryloylmorpholine, 7-amino-3,7-dimethyloctyl (meth) acrylate. , Isobutoxymethyl (meth) acrylamide, isobornyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl diethylene glycol (meth) acrylate, t-octyl (meth) acrylamide, diacetone ( (Meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, lauryl (meth) acrylate, dicyclopentadiene (meth) acrylate, dicyclo Nthenyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, N, N-dimethyl (meth) acrylamide, tetrachlorophenyl (meth) acrylate, 2-tetrachlorophenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) ) Acrylate, tetrabromophenyl (meth) acrylate, 2-tetrabromophenoxyethyl (meth) acrylate, 2-trichlorophenoxyethyl (meth) acrylate, tribromophenyl (meth) acrylate, 2-tribromophenoxyethyl (meth) acrylate 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, phenoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, Tachlorophenyl (meth) acrylate, pentabromophenyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxytripropylene glycol (meth) acrylate, bornyl (meth) acrylate, methyltriethylenedi Examples include glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, and compounds represented by the following general formulas (1) to (3).

（式中、Ｒ^１は、それぞれ独立に水素原子又はメチル基を示し、Ｒ^２は、炭素数２〜６、好ましくは２〜４のアルキレン基を示し、Ｒ^３は、水素原子又は炭素数１〜１２、好ましくは１〜９のアルキル基を示し、Ｒ^４は、炭素数２〜８、好ましくは２〜５のアルキレン基を示す。ｒは、０〜１２、好ましくは１〜８の整数であり、ｑは、１〜８、好ましくは１〜４の整数である。）

(In the formula, each R ¹ independently represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, and R ³ represents a hydrogen atom or 1 carbon atom. -12, preferably an alkyl group having 1-9, R ⁴ represents an alkylene group having 2-8 carbon atoms, preferably 2-5, r is an integer of 0-12, preferably 1-8. And q is an integer of 1 to 8, preferably 1 to 4.)

  Examples of the bifunctional monomer include ethylene glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and tricyclodecanediyldimethylenedi (Meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether Acid adduct, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyester di (meth) acrylate, polyethylene glycol di (meth) Chryrate, EO-modified bisphenol A di (meth) acrylate, PO-modified bisphenol A di (meth) acrylate, EO-modified hydrogenated bisphenol A di (meth) acrylate, PO-modified hydrogenated bisphenol A di (meth) acrylate, EO-modified bisphenol F Examples include di (meth) acrylate and (meth) acrylate of phenol novolac polyglycidyl ether.

The total blending ratio of the monofunctional monomer and the bifunctional monomer is 0 to 15% by mass, preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and further preferably 0, based on 100% by mass of the resin component. % By mass. When the blending ratio exceeds 15% by mass, the blending ratio of other components (particularly the component (A)) is decreased, the photocurability of the composition is decreased, and multistage lamination becomes difficult, and a desired three-dimensional shape is obtained. It may become impossible to manufacture a shaped article having
As an example of the commercial item of a monofunctional monomer, Aronix M-113 (above, Toagosei Co., Ltd. make), etc. are mentioned.
Examples of commercially available products of bifunctional monomers include Aronix M-210 and M-220 (manufactured by Toagosei Co., Ltd.).

In the composition of the present invention, a sintering aid may be blended in order to accelerate firing when firing a three-dimensional structure obtained by photocuring to obtain a metal structure. Examples of the sintering aid include glass paste and low melting point metals (for example, lead, tin, etc.).
The compounding quantity of a sintering auxiliary agent is a ratio in a resin component, and is 1-10 mass% normally.
Furthermore, the composition of the present invention may contain various additives as optional components other than those described above within a range not impairing the object and effects of the present invention. Such additives include epoxy resin, polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene block copolymer, allyl ether copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, Polymers and oligomers such as fluorine-based oligomers, silicone-based oligomers, polysulfide-based oligomers; polymerization inhibitors such as phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization initiation aids; leveling agents; Agents; surfactants; plasticizers; ultraviolet absorbers; silane coupling agents; pigments and dyes other than the above light absorbers; inorganic fine particles or organic fine particles (but not corresponding to component (C)); triethanolamine, Methyldiethano Amine compounds such as amine, triethylamine and diethylamine, thioxanthone and derivatives thereof, anthraquinone and derivatives thereof, anthracene and derivatives thereof, perylene and derivatives thereof, photosensitizers (polymerization accelerators) such as benzophenone and benzoin isopropyl ether; vinyl ethers And reactive diluents such as vinyl sulfides, vinyl urethanes, urethane acrylates, and vinyl ureas.

The photocurable composition of the present invention can be produced by uniformly mixing the above components (A) to (C) and optional components blended as necessary.
The viscosity of the composition thus obtained is preferably 50 to 50,000 mPa · s, more preferably 50 to 10,000 mPa · s at 25 ° C.
The photocurable composition of the present invention is suitable for producing a small three-dimensional modeled object by an optical modeling method.
In order to use the composition of the present invention for stereolithography, the curing depth (500 mJ / cm ² ) of the composition is preferably 50 to 300 μm, more preferably 70 to 250 μm, and particularly preferably 100 to 200 μm.

Next, the metal shaped article and the manufacturing method thereof according to the present invention will be described.
The manufacturing method of the metal modeling thing of this invention was obtained by the process (a) which manufactures the three-dimensional modeling object which consists of a laminated body of the hardened | cured material of the said photocurable composition by the optical modeling method, and the process (a). The process includes a step (b) of cleaning the three-dimensional model and a step (c) of firing the three-dimensional model after washing to obtain a metal model.
[Step (a)]
A process (a) is a process of manufacturing the three-dimensional molded item which consists of a laminated body of the hardened | cured material of the said photocurable composition with an optical modeling method.
Specifically, the photocurable composition is irradiated with light to form a cured product (cross-section cured layer) of the composition, and the composition is supplied again on the cured product (cross-sectional cured layer). By irradiating light, a cured product (cross-section cured layer) of the composition is further formed, and thereafter, by repeating this, a three-dimensional structure formed by laminating and integrating a plurality of cured products (cross-sectional cured layer) Can be obtained.

The method for irradiating the photocurable composition with light is not particularly limited, and various methods can be employed. For example, (a) a method of irradiating the composition while scanning laser light or convergent light obtained using a lens, a mirror, etc., (b) using a mask having a light transmission portion of a predetermined pattern, A method of irradiating the composition with non-converged light through a mask; (c) using a light guide member formed by bundling a large number of optical fibers; and composing light through the optical fiber corresponding to a predetermined pattern in the light guide member A method of irradiating an object, (d) a method of repeatedly executing collective exposure for each predetermined region, and the like can be employed.
Moreover, the irradiation position (irradiation surface) of light can be moved continuously or stepwise from the uncured portion to the uncured portion. By moving in this way, the cured portions can be stacked to form a desired three-dimensional shape. The irradiation position can be moved by various methods, for example, by moving any of the light source, the container for the composition, and the already cured portion of the composition, or additionally supplying the composition to the container. And the like.
Moreover, when the composition is accommodated in the container, the light irradiation surface may be either the liquid surface of the composition or the contact surface with the vessel wall of the translucent container. When the liquid surface of the composition or the contact surface with the vessel wall is used as the light irradiation surface, the light can be irradiated directly from the outside of the container or through the vessel wall.

As a manufacturing method of the three-dimensional molded item of a process (a), the optical lamination modeling method is especially preferable.
The optical layered modeling method is formed by converting three-dimensional CAD data into slice data at regular intervals, and irradiating a liquid photocurable composition with a single layered body corresponding to the slice data, Hereinafter, the same operation is repeated, and it refers to a technique for forming a modeled object composed of a laminate of layered bodies.
According to the optical layered modeling method, a three-dimensional modeled object having a scale having a side length of several millimeters to several meters, typically several centimeters to several tens of centimeters is obtained.
The scale is a scale expressed as a cube.

Here, the suitable example of the manufacturing method of a three-dimensional molded item is demonstrated using FIG. FIG. 1 is a diagram illustrating an example of an optical layered modeling method.
In FIG. 1, a photocurable composition 1 is accommodated in a container 2, and a support stage 3 is provided so as to be movable up and down.
First, as shown in (a) of FIG. 1, the support stage 3 is lowered (sedimented) by a minute amount from the liquid level 4 of the composition 1 in the container 2 containing the photocurable composition 1. Thus, the composition 1 is supplied onto the support stage 3 to form a thin layer of the composition 1. Next, the cured product (cured resin layer) 6 of the composition 1 is formed by selectively irradiating the thin layer with light 8 through the mask 5.
Next, as shown in FIG. 1 (b), the support stage 3 is lowered (sedimented) by a small amount, and the composition 1 is supplied onto the cured product 6 so that a thin layer of the composition is obtained. Form again. Next, by selectively irradiating the thin layer with light 8 through the mask 5, a new cured product 7 is further formed on the cured product 6 continuously and integrally laminated thereon. . Then, by repeating this step a predetermined number of times while changing or not changing the pattern irradiated with light, a three-dimensional modeled object in which a plurality of cured products are integrally laminated is modeled.
The obtained three-dimensional molded item consists of the laminated body of the hardened | cured material of the photocurable composition of this invention.
In the present invention, the thickness of the cured product layer is preferably 50 to 200 μm, more preferably 60 to 180 μm, and particularly preferably 70 to 150 μm.

[Step (b)]
Step (b) is a step of washing the three-dimensional structure obtained in step (a).
The remaining unreacted composition can be removed by washing the three-dimensional structure.
Cleaning methods include alcohol-based organic solvents typified by alcohols such as isopropyl alcohol and ethyl alcohol; ketone-based organic solvents typified by acetone, ethyl acetate, methyl ethyl ketone, and the like; aliphatic organic solvents typified by terpenes A method of cleaning using a cleaning agent such as a low-viscosity thermosetting resin and a photo-curable resin.
Further, the three-dimensional structure can be further cured by being irradiated or heated with an ultraviolet lamp or the like as necessary.

[Step (c)]
A process (c) is a process of baking the solid modeling thing washed at the process (b), and obtaining a metal modeling thing. A metal shaped article can be obtained by heat-treating the three-dimensional shaped article to remove the resin component.
Specifically, the three-dimensional modeled object after washing is fired in a reducing atmosphere, preferably at a temperature of 400 ° C. or higher. As the reducing atmosphere, a hydrogen atmosphere is preferable. Alternatively, a mixed gas of hydrogen and nitrogen, helium, argon, or the like can be used. The firing temperature is preferably 400 ° C. or higher, more preferably 450 ° C. or higher, further preferably 500 ° C. or higher, and particularly preferably 550 ° C. or higher. When the temperature is lower than 400 ° C., firing is insufficient, the mechanical strength of the metal shaped article is inferior, and the conductivity of the metal shaped article is also insufficient.
The upper limit of the firing temperature is preferably 1,000 ° C., more preferably 900 ° C., and particularly preferably 800 ° C. from the viewpoint of saving energy costs.
The firing time is preferably 10 minutes to 1 hour, more preferably 15 to 50 minutes, and particularly preferably 20 to 40 minutes.
In the present invention, it is preferable to perform firing in an oxidizing atmosphere before firing in a reducing atmosphere. By firing in an oxidizing atmosphere, the resin component can be reliably removed from the three-dimensional modeled object, and a metal modeled article having excellent conductivity and gloss can be obtained. Examples of the oxidizing atmosphere include an oxygen-containing atmosphere (for example, air).
The firing temperature is preferably 400 ° C. or higher, more preferably 450 ° C. or higher, further preferably 500 ° C. or higher, and particularly preferably 550 ° C. or higher. When the temperature is less than 400 ° C., the effect of improving conductivity and gloss is insufficient.
The upper limit of the firing temperature is preferably 1,000 ° C., more preferably 900 ° C., and particularly preferably 800 ° C. from the viewpoint of saving energy costs.
The firing time is preferably 10 minutes to 1 hour, more preferably 15 to 50 minutes, and particularly preferably 20 to 40 minutes.

The metal shaped article has a small volume resistance value and good electrical conductivity. The volume resistance value of the metal shaped article is preferably 1.0 × 10 ⁻¹ Ω · cm or less, more preferably 1.0 × 10 ⁻² Ω · cm or less, and further preferably 1.0 × 10 ⁻³ Ω · cm. cm or less, particularly preferably 1.0 × 10 ⁻⁴ Ω · cm or less.
The metal shaped article can be suitably used for MEMS and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to the aspect as described in a following example. In addition, the following "part" shows a mass part.

[Example 1]
In a container equipped with a stirrer, 80 g of dipentaerythritol hexaacrylate, 20 g of ethoxylated trimethylolpropane triacrylate, 3.0 g of Irgacure 819 (radical polymerization initiator, manufactured by Ciba Specialty Chemicals), 2,4- 2.0 g of diethylthioxanthone (sensitizer), 0.5 g of 4-dimethylaminobenzoic acid ethyl ester (polymerization initiation assistant), 0.06 g of SH28PA (leveling agent, manufactured by Toray Dow Corning), SH190 ( After adding 0.19 g of a leveling agent, manufactured by Toray Dow Corning Co., Ltd., and 5 g of glass paste (sintering aid, manufactured by JSR, trade name: FX-008T) and stirring at 60 ° C. for 1 hour, Single particle (manufactured by Kojun Chemical Co., Ltd .; trade name: CUE08PB; number average particle size: 1 μm) 856 g It was added, made of Kika Kogyo Co., Ltd. T. K. A photocurable composition was prepared by uniformly dispersing using HOMODISPER.
Subsequently, using the photocurable composition obtained, a three-dimensional model was formed by optical modeling with an optical layered modeling apparatus (product name: SCS-300P; manufactured by Sony Manufacturing Systems). The three-dimensional model was manufactured by firing the three-dimensional model at 500 ° C. or 800 ° C. for 30 minutes in a 3% hydrogen atmosphere.
About the physical property of the three-dimensional molded item which consists of a photocurable composition and copper, it evaluated by the following method. The results are shown in Table 1.
(Transparency)
Resin was apply | coated on the glass substrate and the rotation speed was adjusted so that it might become a film thickness of 10 micrometers using a spin coater. The transmittance was measured using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation).
(Multi-stage lamination)
A block model (width 500 μm, height: 500 μm, number of layers: 5 layers) was modeled at a stacking pitch of 50 μm using the optical layered modeling apparatus, and the side of the model was observed with a laser microscope. A case where there was no defect such as delamination was indicated as “◯”, and a case where there was a defect was indicated as “X”.
(Volume resistance value)
The volume resistance value of the three-dimensional structure made of copper was measured according to JIS K 7194.

[Example 2]
The three-dimensional structure is first fired at 500 ° C. for 30 minutes in an air atmosphere, and then fired at 500 ° C. or 800 ° C. for 30 minutes in a 3% hydrogen (H ₂ ) atmosphere to form a three-dimensional structure made of copper. Evaluation was performed in the same manner as in Example 1 except that the product was obtained. The results are shown in Table 1.
[Example 3]
In a container equipped with a stirrer, 80 g of dipentaerythritol hexaacrylate, 20 g of ethoxylated trimethylolpropane triacrylate, 3.0 g of Irgacure 819 (manufactured by Ciba Specialty Chemicals), and 4-dimethylaminobenzoic acid ethyl ester 0 0.5 g, 0.028 g of SH28PA (manufactured by Dow Corning Toray), 0.19 g of SH190 (manufactured by Dow Corning Toray), and 5 g of glass paste (manufactured by JSR) as a sintering aid, After stirring at 60 ° C. for 1 hour, 839 g of simple copper particles (manufactured by Kojun Chemical Co., Ltd .; trade name; CUE08PB; number average particle size: 1 μm) were added. K. A photocurable composition was prepared by uniformly dispersing using HOMODISPER.
In the same manner as in Example 1, a three-dimensional structure made of copper was manufactured, and various physical properties were evaluated. The results are shown in Table 1.
[Example 4]
The three-dimensional structure was first fired at 500 ° C. for 30 minutes in an air atmosphere, and then fired at 500 ° C. or 800 ° C. for 30 minutes in a 3% hydrogen atmosphere, except that a three-dimensional structure made of copper was obtained. Evaluation was performed in the same manner as in Example 3. The results are shown in Table 1.

  From Table 1, it can be seen that the photocurable composition of the present invention has good transmissivity with respect to light of 405 nm, and has excellent multi-layer stackability. Moreover, it can be seen from Table 1 that the metal shaped article using the photocurable composition of the present invention has a small volume resistance value and good electrical conductivity.

It is a figure which shows an example of the optical lamination molding method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photocurable composition 2 Container 3 Support stage 4 Liquid level of photocurable composition 5 Mask 6,7 Hardened | cured material (hardened layer)
8 light 11 light source

Claims (10)

A photocurable composition for producing a three-dimensional modeled object using an optical modeling method, wherein (A) a monomer having three or more ethylenically unsaturated groups, (B) a photopolymerization initiator, and (C ) Metal fine particles having a number average particle diameter of 0.5 to 3 μm by dynamic light scattering method, and (A) the content ratio of the monomer having 5 or more ethylenically unsaturated groups in the component is 50% by mass or more. and the blending ratio of the component (C) is a 85 to 95 wt% of the total amount of the photocurable composition as 100 mass%, and the blending ratio of each of components (a) and component (B), (C) 70-95 mass% and 0.01-10 mass% of photocurable compositions for optical shaping | molding characterized by the total quantity of the photocurable composition except a component being 100 mass%. The monomer having 5 or more ethylenically unsaturated groups in the component (A) is at least one selected from the group consisting of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate. The photocurable composition according to claim 1.   The component (C) contains one or more metals selected from the group consisting of copper, iron, nickel, cobalt, aluminum, gold, silver, tin, platinum, zinc, palladium, iridium, titanium, and tantalum. Or the photocurable composition of 2.   The photocurable composition according to any one of claims 1 to 3, which is for optical layered modeling.   The three-dimensional molded item which consists of hardened | cured material of the photocurable composition of any one of Claims 1-4.   After irradiating light to the photocurable composition of any one of Claims 1-4, and forming the cured layer of the said composition, the said composition is again supplied on this cured layer. A method for producing a three-dimensional modeled object that forms a three-dimensional modeled object by irradiating light to further form a cured layer of the composition, and thereafter repeating this to laminate and integrate a plurality of cured layers.   The method for producing a three-dimensional structure according to claim 6, wherein the thickness of the hardened layer is 50 to 200 μm.   A metal model including a single metal, which is obtained by firing the three-dimensional model according to claim 5.   The photocurable composition according to any one of claims 1 to 4 is cured by an optical modeling method to obtain a three-dimensional model, and the three-dimensional model is baked to obtain a metal model. The manufacturing method of the metal molded article including the baking process to obtain. The method for producing a metal shaped article according to claim 9 , wherein the firing step is to heat at 400 ° C. or higher in a reducing atmosphere after heating at 400 ° C. or higher in an oxidizing atmosphere.

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