WO2023166781A1

WO2023166781A1 - Photocurable resin composition, cured object, three-dimensional shaped object, and method for producing casting mold

Info

Publication number: WO2023166781A1
Application number: PCT/JP2022/039038
Authority: WO
Inventors: 高輔井川; 茂年西澤
Original assignee: Dic株式会社
Priority date: 2022-03-03
Filing date: 2022-10-20
Publication date: 2023-09-07
Also published as: TW202336048A; JPWO2023166781A1

Abstract

The present invention provides a photocurable resin composition characterized by comprising a photopolymerization initiator (A) and a polyfunctional (meth)acrylate (B), wherein the amount of the photopolymerization initiator (A) is in the range of 10-30 parts by mass, excluding 10 parts by mass, per 100 parts by mass of the polyfunctional (meth)acrylate (B). The photopolymerization initiator (A) may at least comprise a first photopolymerization initiator (A-1), which has at least one maximal-absorption wavelength in a wavelength range of 350 nm and longer, and a second photopolymerization initiator (A-2), which has no maximal-absorption wavelength in the wavelength range of 350 nm and longer and has a maximal-absorption wavelength in a wavelength range below 350 nm. A three-dimensional shaped object comprising a cured object obtained by curing the photocurable resin composition has a high hardness and is excellent in terms of eliminability by high-temperature heating, shaping accuracy, and casting property.

Description

Photocurable resin composition, cured product, three-dimensional object, and method for producing mold

The present invention relates to a method for producing a photocurable resin composition, a cured product, a three-dimensional model, and a mold.

Methods such as machining and casting are generally used to manufacture molded articles of metal materials. Among them, the casting method can produce metal parts and metal products with complex shapes.
As the casting method, a prototype model of the casting is created with wax or resin, embedded in the investment material, and after the investment material hardens, the prototype model and the investment material are heated to melt, decompose or bake the prototype model. A lost-wax method or the like is known, in which voids are formed in the investment material by removing it, and a molten metal is injected and cast using the voids as a mold. These lost-wax methods are used in the fields of jewelry and dental technology.

In recent years, it has been proposed to form a prototype model of the lost wax method with a photocurable resin composition using a 3D printer (Patent Document 1).

JP 2018-048312 A

However, conventional photocurable resin compositions have a slow curing speed during light irradiation and are difficult to shape, or the curing speed is too fast, so they are difficult to handle because they cure even with a small amount of light exposure, and the molding accuracy decreases. there was a problem.
In addition, the prototype model formed from the composition cannot maintain its shape due to its low hardness, and the extinguishing property is insufficient when heated at high temperatures, leaving residues such as soot in the investment material and degrading the surface of the casting. Alternatively, there was a problem that cracks and splits occurred in the investment material due to the difference in expansion rate between the prototype model and the investment material.

An object of the present invention is to provide a photocurable resin composition excellent in modeling accuracy, and a modeled article having high hardness, erasability when heated at high temperature, and excellent castability.

As used herein, the term "excellent castability" means that when a mold is produced using the model of the present invention as a prototype model, there are no cracks or cracks on the outside and inside of the mold, and the residue of the three-dimensional model inside the mold. , refers to a state in which there is no soot and the transferability of the three-dimensional object to the mold is good.

For these problems, the present inventors contain a photopolymerization initiator (A) and a polyfunctional (meth)acrylate (B), and the content of the photopolymerization initiator (A) is a polyfunctional (meth)acrylate (B) The photocurable resin composition, which is characterized by being in the range of more than 10 parts by mass to 30 parts by mass with respect to 100 parts by mass, has a moderately fast curing speed and excellent modeling accuracy, and the resin composition can be cured. The inventors have found that the molded article obtained by heating has high hardness and is excellent in erasability when heated to high temperature and castability, and completed the present invention.

That is, the present invention includes the following aspects.
(1) containing a photopolymerization initiator (A) and a polyfunctional (meth)acrylate (B),
A photocurable resin composition, wherein the content of the photopolymerization initiator (A) is in the range of more than 10 parts by mass to 30 parts by mass with respect to 100 parts by mass of the polyfunctional (meth)acrylate (B). thing.
(2) The photopolymerization initiator (A) includes a first photopolymerization initiator (A-1) having at least one maximum absorption wavelength in a wavelength range of 350 nm or more, and a maximum absorption wavelength in a wavelength range of 350 nm or more. The photocurable resin composition according to (1), which contains at least a second photopolymerization initiator (A-2) having a maximum absorption wavelength in a wavelength range of less than 350 nm.
(3) The first photopolymerization initiator (A-1) is at least one selected from the group consisting of acylphosphine oxides, bisacylphosphine oxides, titanocene compounds, O-acyloxime compounds, and thioxanthone compounds. The photocurable resin composition according to claim 2.
(4) The second photopolymerization initiator (A-2) is at least one selected from the group consisting of alkylphenone compounds, α-diketone compounds, and iodonium salts (2) or (3) ) The photocurable resin composition described in ).
(5) The mixing ratio [(A-1)/(A-2)] of the second photopolymerization initiator (A-2) to the first photopolymerization initiator (A-1) is 1/100. The photocurable resin composition according to any one of (2) to (4), which is in the range of to 8/10.
(6) The photocurable resin composition according to any one of (1) to (5), wherein the polyfunctional (meth)acrylate (B) contains at least a compound having a polyoxyalkylene group in the molecule in its structure. thing.
(7) The polyfunctional (meth)acrylate (B) contains at least a compound (B-1) having a polyoxyalkylene group and a bisphenol structure in the molecule,
The compound (B-1) is
Formula (I) below:

wherein R ¹ represents a hydrogen atom or a methyl group, multiple R ^1s in the same molecule may be the same or different, m and n each independently represents an integer of 1 or more, and m+n is 2 to 40, the photocurable resin composition according to (6), which is a modified bisphenol A di(meth)acrylate.
(8) The light according to (6) or (7), wherein the polyfunctional (meth)acrylate (B) further contains a compound (B-2) having one or more (meth)acryloyl groups in the molecule. A curable resin composition.
(9) The photocurable resin composition according to (9), wherein the amount of the compound (B-1) in 100 parts by mass of the polyfunctional (meth)acrylate (B) is 40 to 90 parts by mass.
(10) The photocurable resin composition according to any one of (1) to (9), further containing a nonmetallic organic pigment (C).
(11) The photocurable resin composition according to any one of (1) to (10) for stereolithography.
(12) A cured product obtained by photocuring the photocurable resin composition according to any one of (1) to (11).
(13) A three-dimensional object made of the cured product according to (12).
(14) Step (1) of partially or wholly burying the three-dimensional object according to (13) with an investment material;
a step (2) of curing or solidifying the investment material;
A method for manufacturing a casting mold, comprising a step (3) of melting, removing, and/or incinerating the three-dimensional object.
(15) A method for producing a metal casting, comprising the step (4) of pouring a metallic material into the mold obtained by the production method described in (14) and solidifying the metallic material.

According to the present invention, it is possible to provide a photocurable resin composition with excellent modeling accuracy, and a modeled article with high hardness, erasability when heated at high temperatures, and excellent castability. Therefore, when the mold is created, the prototype model can be easily molded, the shape of the prototype model can be maintained, the residue when the prototype model is heated is reduced, and the mold can be prevented from cracking or cracking.

Several embodiments of the invention are described in detail below. However, the present invention is not limited to the following embodiments. In addition, mass % in this specification means the ratio when the whole photocurable resin composition is made into 100 mass % henceforth.
In the present invention, "(meth)acrylate" refers to one or both of acrylate and methacrylate, and "(meth)acryloyl group" refers to one or both of acryloyl group and methacryloyl group.

[(A) Component]
The photopolymerization initiator (A) used in the present invention (also simply referred to as component (A) in this specification) includes chemical species that generate radicals, cations, or anions upon irradiation with ultraviolet rays, electron beams, or the like, or and is not particularly limited as long as the effects of the present invention can be obtained.

Furthermore, the content of the photopolymerization initiator (A) in the present invention is preferably in the range of 3 to 50 parts by weight with respect to 100 parts by weight of the polyfunctional (meth)acrylate (B), and 5 to 40 parts by weight. and most preferably in the range of more than 10 parts by mass and 30 parts by mass or less. When the content is within these ranges, it is possible to improve molding accuracy by appropriately increasing the curing rate, suppress expansion during high-temperature heating, and improve vanishability. Therefore, it is easy to three-dimensionally shape, prevents cracks and cracks during mold formation, can reduce soot residue, and is excellent in castability.

In the present invention, the photopolymerization initiator (A) preferably contains a first photopolymerization initiator (A-1) having at least one maximum absorption wavelength in the wavelength range of 350 nm or longer. By doing so, it has excellent reactivity with the (meth)acrylate compound when irradiated with ultraviolet light (particularly light having a wavelength of about 350 to 450 nm), accelerates the curing speed, and improves molding accuracy. Therefore, three-dimensional modeling becomes easier.

The first photopolymerization initiator (A-1) is at least one selected from the group consisting of acylphosphine oxides, bisacylphosphine oxides, titanocene compounds, O-acyloxime compounds, and thioxanthone compounds. are preferred, and specifically, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4-cyclopentadienyl)bis[2, 6-difluoro-3-(1-pyryl)phenyl]titanium (IV), 1-[4-(phenylthio)phenyl]octane-1,2-dione=2-(O-benzoyloxime), 2,4-diethyl thioxanthone and the like. Among these, it has excellent reactivity with (meth)acrylate compounds and can reduce soot residue during combustion compared to compounds with large molecular weights and complex structures and compounds containing metal atoms in the molecule. Phosphorus compounds are preferred, and specifically 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide are preferred. In addition, these compounds can be used alone or in combination of two or more.

The photopolymerization initiator (A) does not have a maximum absorption wavelength in a wavelength range of 350 nm or more, and further contains a second photopolymerization initiator (A-2) having a maximum absorption wavelength in a wavelength range of less than 350 nm. is preferred.
A large amount of the second photopolymerization initiator (A-2) remains unreacted in the shaped article even after irradiation with ultraviolet rays (especially light with a wavelength of around 350 to 450 nm). Therefore, it is conceivable that when the modeled object is heated, radicals, cations, or anions are generated and react with the unreacted (meth)acrylate compound to partially cure the modeled object. Therefore, by blending the second photopolymerization initiator (A-2), it is possible to suppress the expansion during heating at high temperature, and to prevent the occurrence of cracks and cracks in the mold during mold preparation. That is, it is excellent in castability.

The second photopolymerization initiator (A-2) is preferably at least one selected from the group consisting of alkylphenone compounds, α-diketone compounds, and iodonium salts. , 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane -1-one, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropynyl)benzyl)phenyl)-2-methylpropane-1- one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2 -dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, methyl benzoylformate, bis(2-phenyl-2-oxoacetate)oxy Bisethylene, commercially available iodonium salts (eg, trade name "Omnicat 250", manufactured by IGM), and the like. Among these, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,2-dimethoxy-2-phenylacetophenone is more preferred. In addition, these compounds can be used alone or in combination of two or more.

As described above, the addition of the first photopolymerization initiator (A-1) can increase the curing speed, and the addition of the second photopolymerization initiator (A-2) can suppress the expansion of the modeled product when heated to a high temperature. Furthermore, the first photopolymerization initiator (A-1) and the second photopolymerization initiator (A-2) also contribute to the improvement of disappearance during high-temperature heating.
On the other hand, if the blending amount of the first photopolymerization initiator (A-1) is too large, problems such as deterioration in modeling accuracy due to excessive acceleration of the curing speed may occur.
Therefore, while moderately adjusting the curing speed to improve the modeling accuracy, it is possible to improve the disappearance during high-temperature heating and suppress the expansion, so the second photopolymerization initiator (A-1). The mixing ratio [(A-1)/(A-2)] of the photopolymerization initiator (A-2) is preferably in the range of 1/100 to 1/1, and is 1/100 to 9/10. is more preferred, and a range of 1/100 to 8/10 is particularly preferred.

[(B) Component]
The composition of the present invention further contains a polyfunctional (meth)acrylate (B) (also referred to herein simply as component (B)). It is preferable that the component (B) has an acryloyl group from the viewpoint of easy obtaining of high reaction speed and modeling accuracy and easy three-dimensional stereolithography. On the other hand, the methacryloyl group has greater steric hindrance at the α-position of the carbon-carbon double bond than the acryloyl group, so depolymerization of the polymer is likely to occur, and the disappearance of the component (B) is high when heated at high temperatures. preferably has a methacryloyl group.

Specific examples of component (B) include neopentylglycol hydroxypivalate di(meth)acrylate, propylene oxide-modified tri(meth)acrylate of glycerin, 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, tris( hydroxyethyl)isocyanuric acid di(meth)acrylate, 3,9-bis[1,1-dimethyl-2-(meth)acryloyloxyethyl]-2,4,8,10-tetraoxospiro[5.5]undecane , dioxane glycol di(meth)acrylate, (EO) or (PO) modified bisphenol A di(meth)acrylate, (EO) or (PO) modified bisphenol E di(meth)acrylate, (EO) or ( PO) modified bisphenol F di(meth)acrylate, (EO) or (PO) modified bisphenol S di(meth)acrylate, (EO) or (PO) modified 4,4'-oxydibisphenol di Bifunctional (meth)acrylate such as (meth)acrylate;

EO-modified glycerol tri(meth)acrylate, PO-modified glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, EO-modified phosphate tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, caprolactone-modified tri Methylolpropane tri(meth)acrylate, HPA-modified trimethylolpropane tri(meth)acrylate, (EO) or (PO)-modified trimethylolpropane tri(meth)acrylate, alkyl-modified dipentaerythritol tri(meth)acrylate, tris (acryloxyethyl) trifunctional (meth)acrylates such as isocyanurate;

Tetrafunctional (meth)acrylates such as ditrimethylolpropane tetra(meth)acrylate, pentaerythritol-ethoxytetra(meth)acrylate, pentaerythritol-letetra(meth)acrylate;

Pentafunctional (meth)acrylates such as dipentaerythritol hydroxypenta(meth)acrylate and alkyl-modified dipentaerythritol penta(meth)acrylate;

A hexafunctional (meth)acrylate such as dipentaerythritol hexa(meth)acrylate can be used. These may be used alone, or may be used by appropriately mixing them in order to adjust curability, viscosity and the like.

Component (B) is likely to decompose when the formed three-dimensional object is heated to a high temperature, and can generate water and carbon dioxide to reduce soot residue. It is preferable to contain. Among them, it is preferable to contain a compound having a polyoxyalkylene group in its structure.

Component (B) particularly preferably contains a compound (B-1) having a polyoxyalkylene group and a bisphenol structure in the molecule. Having a bisphenol structure accelerates the curing speed, improves modeling accuracy, and facilitates three-dimensional modeling.

Specifically, the compound (B-1) used in the present invention is
Formula (I) below:

wherein R ¹ represents a hydrogen atom or a methyl group, multiple R ^1s in the same molecule may be the same or different, and m and n each independently represents an integer of 1 or more.

In the compound (B-1), when m+n (modified amount) in the formula (I) is 2 or more, soot residue during firing can be reduced. From a similar point of view, m+n may be 4 or more, or 6 or more. Further, m+n should be 40 or less, preferably 30 or less. By doing so, compared with the case where m+n exceeds 40, the toughness and strength of the formed three-dimensional object are improved.
Further, when the polyfunctional (meth)acrylate (B) contains a plurality of modified bisphenol A di(meth)acrylates of formula (I) with different m+n, the average thereof should be 2-40.

When the compound (B-1) represented by the formula (I) has a methacryloyl group in the molecule, soot residue during firing can be reduced compared to the case of having an acryloyl group. On the other hand, the compound (B-1) having an acryloyl group may be used when the improvement of the curing speed and molding accuracy is given priority over the reduction of soot residue.

As the compound (B-1) used in the present invention, for example, commercially available products MIRAMER M240, MIRAMER M241, MIRAMER M244, MIRAMER M249, MIRAMER M2100, MIRAMER M2101, MIRAMER M2200, MIRAMER M2300, MIRAMER M2301 (all product names: Miwon UV curable resin sold under the name of Specialty Chemical Co.) can be used.

The polyfunctional (meth)acrylate (B) may contain a photopolymerizable component other than the compound (B-1) as long as the effects of the present invention can be obtained. For example, it may further contain a compound (B-2) having one or more (meth)acryloyl groups in the molecule.

The compound (B-2) used in the present invention is preferably a compound containing only a hydrogen atom, a carbon atom, and an oxygen atom because it can reduce the residue at the time of baking, and alcohol and (meth)acrylic acid are A (meth)acrylate compound obtained by dehydration condensation is particularly preferred.
Examples of the compound (B-2) include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, dipropylene glycol and tripropylene glycol. , neopentyl glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10 - with alcohols such as decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, cyclohexanedimethylol, 1,4-cyclohexanediol, and tricyclodecanedimethylol; Reaction products of (meth)acrylic acid can be used. These compounds can be used alone or in combination of two or more. Among them, from the viewpoint of improving the hardness of the three-dimensional object, neopentyl glycol di (meth) acrylate or polypropylene glycol di (meth) acrylate is preferable, and from the viewpoint of reducing soot residue during baking, neopentyl glycol dimethacrylate or polypropylene glycol. Dimethacrylate is more preferred.

Examples of the compound (B-2) used in the present invention include commercially available products MIRAMER M213, MIRAMER M220, MIRAMER M221, MIRAMER M222, MIRAMER M231, MIRAMER M232, MIRAMER M233, MIRAMER M235, MIRAMER M270, MIRAMER M280, MIRAMER M281, MIRAMER M282, MIRAMER M283, MIRAMER M284, MIRAMER M286, MIRAMER M2040, MIRAMER M2053 (both product names. Miwon Specialty Chemical), NK Ester A-200, NK Ester A-400, NK Ester A-600, NK Ester A-1000, NK ester APG-100, NK ester APG-200, NK ester APG-400, NK ester APG-700, NK ester APMG-65, NK ester 2G, NK ester 3G, NK ester 4G, NK ester 9G, Compounds sold under the names of NK Ester 14G, NK Ester 23G, NK Ester 3PG, and NK Ester 9PG (all product names; manufactured by Shin-Nakamura Chemical Co., Ltd.) can be used.

When the polyfunctional (meth)acrylate (B) in the present invention contains both the compound (B-1) and the compound (B-2), the compounding amount of the compound (B-1) is the polyfunctional (meth) With respect to 100 parts by mass of acrylate (B), it is preferably in the range of 10 parts by mass or more and 99 parts by mass or less, more preferably in the range of 25 parts by mass or more and 95 parts by mass or less, and 40 parts by mass or more and 90 parts by mass. Part or less is particularly preferred. Within these ranges, the curing speed is moderately increased, thereby improving the modeling accuracy and reducing the residue during baking.
The compounding amount of the compound (B-2) is preferably in the range of 5 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the polyfunctional (meth)acrylate (B), and 8 parts by mass or more and 65 parts by mass. The following range is more preferable, and the range of 10 parts by mass or more and 50 parts by mass or less is particularly preferable. By setting it as these ranges, the hardness of hardened|cured material increases.

The method for producing the photocurable resin composition is not particularly limited, and any method may be used.

The photocurable resin composition of the present invention may optionally contain a photosensitizer, an ultraviolet absorber, an antioxidant, a polymerization inhibitor, a silicon-based additive, a fluorine-based additive, a silane coupling agent, and phosphoric acid. Various additives such as ester compounds, organic fillers, inorganic fillers, rheology control agents, defoaming agents and colorants may also be contained.

Examples of the photosensitizer include amine compounds such as aliphatic amines and aromatic amines, urea compounds such as o-tolylthiourea, sodium diethyldithiophosphate, and s-benzylisothiuronium-p-toluenesulfonate. and sulfur compounds such as

Examples of the ultraviolet absorber include 2-[4-{(2-hydroxy-3-dodecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1 , 3,5-triazine, 2-[4-{(2-hydroxy-3-tridecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1, Triazine derivatives such as 3,5-triazine, 2-(2'-xanthenecarboxy-5'-methylphenyl)benzotriazole, 2-(2'-o-nitrobenzyloxy-5'-methylphenyl)benzotriazole , 2-xanthenecarboxy-4-dodecyloxybenzophenone, 2-o-nitrobenzyloxy-4-dodecyloxybenzophenone, and the like. These ultraviolet absorbers can be used alone or in combination of two or more.

Examples of the antioxidants include hindered phenol-based antioxidants, hindered amine-based antioxidants, organic sulfur-based antioxidants, and phosphate-based antioxidants. These antioxidants can be used alone or in combination of two or more.

Examples of the polymerization inhibitor include hydroquinone, methoquinone, di-t-butylhydroquinone, p-methoxyphenol, butylhydroxytoluene, and nitrosamine salts.

Examples of the silicon-based additive include dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, and fluorine. Modified dimethylpolysiloxane copolymer, polyorganosiloxane having an alkyl group or a phenyl group such as an amino-modified dimethylpolysiloxane copolymer, polydimethylsiloxane having a polyether-modified acrylic group, polydimethylsiloxane having a polyester-modified acrylic group etc. These silicon additives can be used alone or in combination of two or more.

Examples of the fluorine-based additive include the "Megaface" series manufactured by DIC Corporation. These fluorine-based additives can be used alone or in combination of two or more.

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxy Propylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)- 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-( 1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, hydrochloride of N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, special aminosilane, 3 -ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanate-topropyltriethoxysilane , allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane and other vinyl-based silane coupling agents;

Diethoxy(glycidyloxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyl epoxy-based silane coupling agents such as triethoxysilane;

a styrene-based silane coupling agent such as p-styryltrimethoxysilane;

(Meta) such as 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. acryloxy-based silane coupling agent;

N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane , 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, etc. amino-based silane coupling agent;

ureido-based silane coupling agents such as 3-ureidopropyltriethoxysilane;

Chloropropyl-based silane coupling agents such as 3-chloropropyltrimethoxysilane;

Mercapto-based silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoquinsilane;

sulfide-based silane coupling agents such as bis(triethoxysilylpropyl) tetrasulfide;

Examples include isocyanate-based silane coupling agents such as 3-isocyanate-propyltriethoxysilane. These silane coupling agents can be used alone or in combination of two or more.

Examples of the phosphate ester compound include those having a (meth)acryloyl group in the molecular structure. Commercially available products include "Kayama-PM-2" and "Kayama- PM-21", "Light Ester P-1M", "Light Ester P-2M", "Light Acrylate P-1A (N)" manufactured by Kyoeisha Chemical Co., Ltd., "SIPOMER PAM 100" and "SIPOMER PAM 200" manufactured by SOLVAY , "Sipomer PAM 300", "Sipomer PAM 4000", "Viscoat #3PA" and "Viscoat #3PMA" manufactured by Osaka Organic Chemical Industry Co., Ltd., "New Frontier S-23A" manufactured by Daiichi Kogyo Seiyaku Co., Ltd. ; ``SIPOMER PAM 5000'' manufactured by SOLVAY, which is a phosphoric acid ester compound having an allyl ether group in the molecular structure, and the like.

Examples of the organic filler include plant-derived solvent-insoluble substances such as cellulose, lignin, and cellulose nanofibers, polymethyl methacrylate beads, polycarbonate beads, polystyrene beads, polyacrylstyrene beads, silicone beads, Organic beads such as glass beads, acrylic beads, benzoguanamine resin beads, melamine resin beads, polyolefin resin beads, polyester resin beads, polyamide resin beads, polyimide resin beads, polyethylene fluoride resin beads, polyethylene resin beads, etc. mentioned. These organic fillers can be used alone or in combination of two or more.

Examples of the inorganic filler include inorganic fine particles such as silica, alumina, zirconia, titania, barium titanate, and antimony trioxide. These inorganic fillers can be used alone or in combination of two or more. In addition, the average particle size of the inorganic fine particles is preferably in the range of 95 to 250 nm, and more preferably in the range of 100 to 180 nm.

When the inorganic fine particles are contained, a dispersing aid can be used. Examples of the dispersing aid include phosphate ester compounds such as isopropyl acid phosphate, triisodecyl phosphite, and ethylene oxide-modified phosphate dimethacrylate. These dispersing aids can be used alone or in combination of two or more. Further, commercially available products of the dispersing aid include, for example, Nippon Kayaku Co., Ltd. "Kayama-PM-21", "Kayama-PM-2", Kyoeisha Chemical Co., Ltd. "Light Ester P-2M" and the like. mentioned.

Examples of the rheology-control agents include amide waxes such as "Disparon 6900" manufactured by Kusumoto Kasei Co., Ltd.; urea-based rheology control agents such as "BYK410" manufactured by Big Chemie; 4200" and other polyethylene waxes; and cellulose acetate butyrates such as "CAB-381-2" and "CAB 32101" manufactured by Eastman Chemical Products.

Examples of the defoaming agent include oligomers containing fluorine or silicon atoms, or oligomers such as higher fatty acids and acrylic polymers.

Examples of the coloring agent include pigments and dyes.

As the pigment, a known and commonly used inorganic pigment or organic pigment can be used.

Examples of the inorganic pigments include titanium oxide, antimony red, red iron oxide, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, carbon black, and graphite.

Examples of the organic pigments include quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, Examples include quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, and azo pigments. These pigments can be used alone or in combination of two or more.

Examples of the dyes include azo dyes such as monoazo and disazo, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinoimine dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, Examples include benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes, perinone dyes, phthalocyanine dyes, and triallylmethane dyes. These dyes can be used alone or in combination of two or more.

Among the above-mentioned colorants, the non-metallic organic pigment (C) (hereinafter also simply referred to as the (C) component) is more preferable from the viewpoint of reducing residue during firing. Specifically, quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, azo pigments and the like are particularly preferred.

The content of the colorant in the composition of the present invention is preferably in the range of 0.001 to 5 parts by mass, more preferably in the range of 0.001 to 1 part by mass, per 100 parts by mass of component (B). is more preferable, and the range of 0.001 to 0.5 parts by mass is particularly preferable. By setting it to these ranges, it is possible to suppress the generation of residue during baking of the shaped article while improving the visibility.

The cured product of the present invention is obtained by curing the photocurable resin composition.

The cured product of the present invention can be obtained by irradiating the photocurable resin composition with ultraviolet rays, and in order to efficiently perform the curing reaction by ultraviolet rays, irradiation is performed in an inert gas atmosphere such as nitrogen gas. Alternatively, irradiation may be performed in an air atmosphere.

UV lamps are generally used as the source of UV light from the standpoint of practicality and economy. Specific examples include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, gallium lamps, metal halide lamps, sunlight, and LEDs. Among these, it is preferable to use an LED as a light source because stable illuminance can be obtained over a long period of time.

The wavelength of the ultraviolet rays is not particularly limited as long as it can cure the photocurable resin composition of the present invention, and can be appropriately selected within the range of 1 to 450 nm.

The ultraviolet irradiation may be performed in one step or in two or more steps.

The three-dimensional object of the present invention can be produced by a known optical three-dimensional modeling method.

Examples of the optical stereolithography method include the stereolithography (SLA) method, the digital light processing (DLP) method, the liquid crystal display method (LCD) method, and the inkjet method.

The stereolithography (SLA) method is a method in which a tank of liquid photocurable resin composition is irradiated with ultraviolet rays at points, and solidification is performed layer by layer while the modeling stage is moved to perform three-dimensional modeling.

In the digital light processing (DLP) method and the liquid crystal display method (LCD) method, a tank of a liquid ultraviolet curable resin composition is irradiated with ultraviolet rays from the surface, and the molding stage is moved to cure layer by layer. This is a method for three-dimensional modeling.

The inkjet stereolithography method is a method in which fine droplets of a photocurable resin composition are discharged from a nozzle so as to draw a predetermined shape pattern, and then irradiated with ultraviolet rays to form a cured thin film. .

Among these optical stereolithography methods, the DLP method is preferable because it enables high-speed modeling using surfaces.

The DLP stereolithography method is not particularly limited as long as it is a method using a DLP stereolithography system. The layer pitch is in the range of 0.01 to 0.2 mm, the irradiation wavelength is in the range of 350 to 410 nm, the light intensity is in the range of 0.5 to 50 mW/cm ² , and the integrated light amount per layer is 1. ~100 mJ/cm ² , and above all, the layering pitch of stereolithography is in the range of 0.02 to 0.1 mm because the molding accuracy of the three-dimensional object is further improved. Preferably, the irradiation wavelength is in the range of 380 to 410 nm, the light intensity is in the range of 5 to 15 mW/cm ² , and the integrated light amount per layer is in the range of 5 to 80 mJ/cm ² .

Since the three-dimensional shaped article of the present invention has excellent castability, the residual rate of the three-dimensional shaped article when fired is preferably 62% or less at 400 ° C. in a nitrogen atmosphere, and preferably 57% or less. is more preferable, and 50% or less is particularly preferable. In the present invention, the residual rate after firing is a value calculated by [(weight at 400° C.)/(initial weight at 25° C.)] in thermogravimetric differential thermal measurement (TG-DTA).

The three-dimensional object of the present invention can be used, for example, in dental materials, automotive parts, aerospace-related parts, electrical and electronic parts, building materials, interiors, jewelry, medical materials, and the like.

Examples of the medical materials include dental hard resin materials such as surgical guides for dental treatment, temporary teeth, bridges, and orthodontic appliances.

In addition, since the three-dimensionally shaped article of the present invention has excellent hardness and castability, it is also suitable for manufacturing a mold using the three-dimensionally shaped article.

As the method for producing the mold, for example, the step (1) of partially or entirely embedding the three-dimensional object of the present invention with an investment material, the step (2) of curing or solidifying the investment material, and the three-dimensional object , a method having a step (3) of removing by melting, removing by decomposition, and/or removing by incineration.

Examples of the investment material include gypsum-based investment materials and phosphate-based investment materials. Examples of the gypsum-based investment materials include silica investment materials, quartz investment materials, and cristobalite investment materials.

The step (1) is a step of partially or wholly burying the three-dimensional object of the present invention with an investment material. At this time, the investment material is preferably mixed with an appropriate amount of water. If the mixing water ratio is too high, the hardening time will be long, and if it is too low, the fluidity will be poor and it will be difficult to pour the investment material. In addition, when the surface active agent is applied to the three-dimensionally shaped article, the investment material is well wetted and blended, so that the surface of the casting is less likely to be roughened, which is preferable. Furthermore, when burying the three-dimensional object, it is preferable to bury the object so that air bubbles do not adhere to the surface of the casting.

The step (2) is a step of curing or solidifying the investment material. When a gypsum-based investment material is used as the investment material, the temperature for solidifying the investment material is preferably in the range of 200 to 400 ° C. It is preferable to solidify by standing still for about 10 to 60 minutes after burying the three-dimensional object. .

The step (3) is a step of removing by melting, removing by decomposition, and/or by incinerating the three-dimensional object. When the three-dimensional object is removed by burning, the burning temperature is preferably in the range of 400 to 1000°C, more preferably in the range of 600 to 800°C.

In addition, a metal casting can be obtained by pouring a metal material into the mold obtained through the steps (1) to (3) and solidifying the metal material (step (4)). Thereby, it becomes possible to manufacture a metal casting corresponding to the prototype of the three-dimensional object.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. (Hereafter, "parts" described with respect to the amount of each component means "parts by mass.")

(Example 1)
In a vessel equipped with a stirrer, 80 parts by mass of bisphenol A ethylene oxide-modified (10 mol addition) dimethacrylate, 20 parts by mass of neopentyl glycol dimethacrylate, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (IGM) and 10 parts by mass of 1-hydroxycyclohexylphenyl ketone (trade name “Omnirad 184” manufactured by IGM) were blended and stirred for 1 hour while controlling the liquid temperature to 60°C. By mixing and uniformly dissolving, a photocurable resin composition (1) was obtained.

(Examples 2 to 14, Comparative Examples 1 to 5)
Photocurable resin compositions (2) to (14) and (R1) to (R5) were obtained in the same manner as in Example 1, except that the compositions were changed to those shown in Tables 1 to 3.

For the photocurable resin compositions (1) to (14) and (R1) to (R5) prepared above, three-dimensional object samples were prepared in the following steps and each test was performed.

(Creation of sample)
For each of the photocurable resin compositions (1) to (14) and (R1) to (R5), a surface exposure method (DLP) stereolithography system ("MAX" manufactured by ASIGA) was used for each evaluation. A three-dimensional object having a predetermined shape was formed.
The lamination pitch of stereolithography was 0.05 to 0.1 mm, the irradiation wavelength was 400 to 410 nm, the illuminance was 8 mW/cm ² , and the light irradiation time was 0.5 to 7 seconds per layer. The three-dimensional object formed under each of the above conditions was ultrasonically cleaned in ethanol. Subsequently, using a high-pressure mercury lamp, the front and back surfaces of the three-dimensional object were irradiated with light so that the cumulative amount of light was 1000 to 2000 mJ/cm ² , and post-cured to prepare a sample.

[Hardness (Shore-D hardness) evaluation method]
JIS K 6253-3: 2012 "Vulcanized rubber and thermoplastic rubber-Determination of hardness-Part 3: Durometer hardness" according to the measurement method described in the hardness of the sample (type D durometer, GS-720R) was measured. Using the sample obtained above (having a rectangular parallelepiped shape of 5 mm×5 mm×3 mm), two samples having the same shape were stacked in the thickness direction of 3 mm to measure the thickness of about 6 mm. However, test pieces containing foreign matter, air bubbles, and scratches were not used. Evaluate based on the following criteria, and pass with 〇.
(Evaluation criteria)
〇 (Shore-D hardness of 60 or more)
× (Shore-D hardness less than 60)

[Method for measuring residual ratio of three-dimensionally shaped object at the time of firing]
The sample prepared above (the shape is a rectangular parallelepiped of 5 mm × 5 mm × 3 mm) was pulverized into 5 to 6 mg pieces as a test piece, and a differential thermogravimetric simultaneous measurement device (TG-DTA: TGA / DSC1 manufactured by Metra-Toledo). was used to measure the mass when the temperature was raised from 25 ° C. to 600 ° C. at 10 ° C./min under a nitrogen atmosphere, and the residual rate at 400 ° C. was [(weight at 400 ° C.) / (initial weight at 25 ° C.) ]. The smaller this value, the better the erasability when heated to a high temperature.
(Evaluation criteria)
A: (Residual rate is less than 57%)
B: (remaining rate is more than 57% and 62% or less)
C: (Residual rate is over 62%)

[Measuring method of modeling accuracy]
For each of the photocurable resin compositions (1) to (14) and (R1) to (R5), a surface exposure method (DLP) stereolithography system (“MAX” manufactured by ASIGA) was used to form a vertical shape. A three-dimensional object was formed so as to have a sheet shape of 5 mm×5 mm wide×1.5 mm thick.
In the stereolithography, the layer pitch was 0.05 mm, the irradiation wavelength was 400 to 410 nm, the illuminance was 8 mW/cm ² , and the light irradiation time was 6 seconds per layer. The formed three-dimensional object was ultrasonically cleaned in ethanol. Subsequently, using a high-pressure mercury lamp, the front and back surfaces of the three-dimensional object were irradiated with light so that the cumulative amount of light was 1000 to 2000 mJ/cm ² , and post-cured to prepare a sample for modeling accuracy measurement.
The thickness of the obtained sample for molding precision measurement was measured with a micrometer. The closer the thickness is to 1.5 mm, the better the modeling accuracy.
(Evaluation criteria)
A (Dimensional error of thickness (1.5 mm) is less than 0.1 mm)
B (Dimensional error of thickness (1.5 mm) is 0.1 mm or more and less than 0.15 mm)
C (Dimensional error of thickness (1.5 mm) is 0.15 mm or more)

[Castability evaluation method]
Using the investment material obtained by mixing cristobalite investment material (Yoshino Gypsum Sales Co., Ltd., Sakura Quick 30) and water at a mass ratio of 100: 33, the sample obtained above (the shape is Fig. 1: Hemisphere with a diameter of 15 mm, a diameter of 15 mm sphere, a ring with a diameter of 15 mm connected by a cylinder with a diameter of 5 mm, total length 42.5 mm) was buried and left at 25 ° C. for 30 minutes to solidify the investment material. Then, the sample was incinerated by heating in an electric furnace heated to 700° C. for 1 hour to prepare a mold. Castability at this time was visually evaluated according to the following criteria. In addition, inside the mold, the mold is cut and visually inspected for cracks, cracks, residue of the three-dimensional model, presence of soot, and whether the transferability of the three-dimensional model to the mold is good or bad. , and 0 was passed.
(Evaluation criteria)
◯: There are no cracks or fissures on the outside or inside of the mold, no residue of the three-dimensional object and no soot inside the mold, and the transferability of the three-dimensional object to the mold is good.
x: At least one of cracks and fissures outside the mold, residue of the three-dimensional object inside the mold, soot residue, and poor transfer of the three-dimensional object to the mold occurs, and the mold cannot be used as a mold.
(Fig. 1)

The evaluation results of each of the above tests are shown in Tables 1-3.

Abbreviations in Tables 1-3 are as follows.
Omnirad819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, manufactured by IGM, trade name "Omnirad819", maximum absorption wavelength: 237 nm, 380 nm
OmniradTPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide, manufactured by IGM, trade name "OmniradTPO", maximum absorption wavelength: 275 nm, 379 nm
Omnirad184: 1-hydroxycyclohexylphenyl ketone, manufactured by IGM, trade name "Omnirad184", maximum absorption wavelength: 243 nm, 331 nm
Omnirad907: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, manufactured by IGM, trade name "Omnirad907", maximum absorption wavelength: 230 nm, 303 nm
Omnirad651: 2,2-dimethoxy-2-phenylacetophenone, manufactured by IGM, trade name "Omnirad651", maximum absorption wavelength: 252 nm, 325 nm
Compound 1: Bisphenol A ethylene oxide-modified (10 mol addition) dimethacrylate, manufactured by Miwon Specialty Chemical, trade name "Miramer M2101"
Compound 2: Bisphenol A ethylene oxide-modified (4 mol addition) dimethacrylate, manufactured by Miwon Specialty Chemical, trade name "Miramer M241"
Compound 3: Bisphenol A ethylene oxide-modified (30 mol addition) dimethacrylate, manufactured by Miwon Specialty Chemical, trade name "Miramer M2301"
Compound 4: Neopentyl glycol dimethacrylate, manufactured by Miwon Specialty Chemical, trade name "Miramer M213"
Compound 5: Polypropylene glycol dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "NK Ester 9PG"
P. R. 122: Pigment Red 122, manufactured by DIC, trade name "FASTOGEN (registered trademark) SUPER MAGENTA R"

As shown in Tables 1 to 3, the photocurable resin compositions of Examples 1 to 14 show good modeling accuracy, and the three-dimensional objects exhibit high hardness and excellent erasability when heated at high temperatures. , it was confirmed that the castability was improved.
On the other hand, the photopolymerization initiator (A), with respect to 100 parts by mass of the component (B), in the three-dimensional shaped objects formed from Comparative Examples 1 to 4 in a proportion of 10 parts by mass or less, disappearance during high-temperature heating And it was confirmed that the castability was inferior. Furthermore, the photopolymerization initiator (A), with respect to 100 parts by mass of the component (B), in the three-dimensional object using Comparative Example 5 containing 30 parts by weight or more, the hardness is lowered, the castability is deteriorated. I found out to do.

Claims

Containing a photopolymerization initiator (A) and a polyfunctional (meth)acrylate (B),
A photocurable resin composition, wherein the content of the photopolymerization initiator (A) is in the range of more than 10 parts by mass to 30 parts by mass with respect to 100 parts by mass of the polyfunctional (meth)acrylate (B). thing.
The photopolymerization initiator (A) includes a first photopolymerization initiator (A-1) having at least one maximum absorption wavelength in a wavelength range of 350 nm or more, and a first photopolymerization initiator (A-1) having a maximum absorption wavelength in a wavelength range of 350 nm or more. 2. The photocurable resin composition according to claim 1, which contains at least a second photopolymerization initiator (A-2) having a maximum absorption wavelength in a wavelength range of less than 350 nm.
The first photopolymerization initiator (A-1) is at least one selected from the group consisting of acylphosphine oxides, bisacylphosphine oxides, titanocene compounds, O-acyloxime compounds, and thioxanthone compounds. 2. The photocurable resin composition according to 2.
Photocurable according to claim 2, wherein the second photopolymerization initiator (A-2) is at least one selected from the group consisting of alkylphenone compounds, α-diketone compounds, and iodonium salts. Resin composition.
The mixing ratio [(A-1)/(A-2)] of the second photopolymerization initiator (A-2) to the first photopolymerization initiator (A-1) is 1/100 to 8/ 3. The photocurable resin composition according to claim 2, which is in the range of 10.
The photocurable resin composition according to claim 1, wherein the polyfunctional (meth)acrylate (B) contains at least a compound having a polyoxyalkylene group in its structure.
The polyfunctional (meth)acrylate (B) contains at least a compound (B-1) having a polyoxyalkylene group and a bisphenol structure in the molecule,
The compound (B-1) is
Formula (I) below:

wherein R 1 represents a hydrogen atom or a methyl group, multiple R 1s in the same molecule may be the same or different, m and n each independently represents an integer of 1 or more, and m+n is 2 to 40, the photocurable resin composition according to claim 6, which is a modified bisphenol A di(meth)acrylate.
The photocurable resin composition according to claim 6, wherein the polyfunctional (meth)acrylate (B) further contains a compound (B-2) having one or more (meth)acryloyl groups in the molecule.
The photocurable resin composition according to claim 8, wherein the compound (B-1) is compounded in an amount of 40 to 90 parts by mass in 100 parts by mass of the polyfunctional (meth)acrylate (B).
The photocurable resin composition according to claim 1, which further contains a nonmetallic organic pigment (C).
The photocurable resin composition according to any one of claims 1 to 10 for stereolithography.
A cured product obtained by photocuring the photocurable resin composition according to any one of claims 1 to 10.
A three-dimensional object made of the cured product according to claim 12.
Step (1) of partially or completely embedding the three-dimensional object according to claim 13 with an investment material;
a step (2) of curing or solidifying the investment material;
A method for manufacturing a casting mold, comprising a step (3) of melting, removing, and/or incinerating the three-dimensional object.
A method for producing a metal casting, comprising a step (4) of pouring a metallic material into the mold obtained by the production method according to claim 14 and solidifying the metallic material.