JP7463718B2 - Curable resin composition, cured product, and three-dimensional object - Google Patents

Description

The present invention relates to a curable resin composition, a cured product, and a three-dimensional object.

In recent years, optical 3D modeling (photolithography) has come to be used as a method for producing resin molded products. This method uses 3D shape data designed using 3D design systems such as 3D CAD to selectively polymerize and harden a curable resin composition with active energy rays such as ultraviolet lasers to produce 3D objects. This optical 3D modeling method can handle complex shapes that are difficult to produce using cutting, has a short production time, and is easy to handle, so it is being widely used not only for resin molded products but also for the production of prototype models for industrial products.

A typical example of the optical three-dimensional modeling method is a method in which a liquid photocurable resin in a container is irradiated from above with a computer-controlled spot-shaped ultraviolet laser to harden one layer of a given thickness, the model is lowered by one layer to supply liquid resin on top of the layer, and similarly irradiated and hardened with ultraviolet laser light in the same manner as above, and stacked, and a three-dimensional model is obtained by repeating this operation. Recently, in addition to the pointillism method using a spot-shaped ultraviolet laser, a surface exposure method has been increasing in which a light source other than a laser such as an LED is used, and ultraviolet light is irradiated from below through a transparent container containing a photocurable resin through a planar drawing mask called a DMD (digital micromirror device) in which multiple digital micromirror shutters are arranged in a plane, to harden one layer of a given cross-sectional shape pattern, the model is raised by one layer, and the next layer is irradiated and hardened in the same manner as above, and stacked in sequence to obtain a three-dimensional model.

The photocurable resin used in the optical three-dimensional modeling method is required to have various properties, such as low viscosity, the ability to form a smooth liquid surface, and excellent curing properties. As such photocurable resins, resin compositions mainly composed of radically polymerizable compounds are known (see, for example, Patent Documents 1 and 2), but these do not satisfy the increasingly high performance requirements in recent years for elastic modulus, elongation, and impact resistance.

Therefore, there was a demand for a material that had low viscosity and could form a cured product with excellent mechanical properties.

Japanese Patent Application Laid-Open No. 7-228644 JP 2008-189782 A

The problem that the present invention aims to solve is to provide a curable resin composition, a cured product, and a three-dimensional object that have low viscosity and excellent mechanical properties in the cured product.

As a result of intensive research into solving the above problems, the inventors discovered that the above problems could be solved by using a curable resin composition containing a specific urethane resin and a specific acrylate compound, and thus completed the present invention.

That is, the present invention relates to a curable resin composition containing a urethane resin (A) having a (meth)acryloyl group, and a monofunctional (meth)acrylate compound (B1) and/or a bifunctional (meth)acrylate compound (B2), in which the urethane resin (A) contains polyether polyol (a1), polyisocyanate (a2), and a compound (a3) having a hydroxyl group and a (meth)acryloyl group as essential reaction raw materials, and the polyether polyol (a1) contains polytetramethylene glycol. The present invention also relates to a curable resin composition, a cured product, and a three-dimensional object.

The curable resin composition of the present invention has low viscosity and is capable of forming a cured product with excellent mechanical properties, and therefore can be suitably used as a resin composition for optical three-dimensional modeling.

The curable resin composition of the present invention is characterized by containing a urethane resin (A) having a (meth)acryloyl group, and a monofunctional (meth)acrylate compound (B1) and/or a bifunctional (meth)acrylate compound (B2).

In the present invention, "(meth)acrylate" means acrylate and/or methacrylate. Furthermore, "(meth)acryloyl" means acryloyl and/or methacryloyl. Furthermore, "(meth)acrylic" means acrylic and/or methacrylic.

The urethane resin (A) essentially contains a (meth)acryloyl group.

The urethane resin (A) is made of polyether polyol (a1), polyisocyanate (a2), and a compound having a hydroxyl group and a (meth)acryloyl group (a3) as essential reactive raw materials.

The polyether polyol (a1) used must be polytetramethylene glycol.

As the polyether polyol (a1), in addition to the polytetramethylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, etc. can be used as necessary. These polyether polyols can be used alone or in combination of two or more kinds.

The number average molecular weight (Mn) of the polyether polyol (a1) is preferably in the range of 700 to 3,500, and more preferably in the range of 1,000 to 3,000, since a curable resin composition that can form a cured product having low viscosity and excellent mechanical properties can be obtained. In the present invention, the "number average molecular weight (Mn)" is a value measured using gel permeation chromatography (GPC).

Examples of the polyisocyanate (a2) include aliphatic diisocyanate compounds such as butane diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate; alicyclic diisocyanate compounds such as norbornane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate; tolylene diisocyanate, Examples of the polyisocyanate include aromatic diisocyanate compounds such as xylylene diisocyanate, tetramethylxylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, and o-tolidine diisocyanate; polymethylene polyphenyl polyisocyanate having a repeating structure represented by the following structural formula (1); and isocyanurate-modified, biuret-modified, and allophanate-modified versions of these polyisocyanates. These polyisocyanates can be used alone or in combination of two or more.

［式中、Ｒ^１はそれぞれ独立に水素原子、炭素原子数１～６の炭化水素基の何れかである。Ｒ^２はそれぞれ独立に炭素原子数１～４のアルキル基、または構造式（１）で表される構造部位と＊印が付されたメチレン基を介して連結する結合点の何れかである。ｌは０または１～３の整数であり、ｍは１～１５の整数である。］

[In the formula, R ¹ is independently either a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R ² is independently either an alkyl group having 1 to 4 carbon atoms, or a bonding point connecting the structural portion represented by structural formula (1) via a methylene group marked with an *. l is 0 or an integer of 1 to 3, and m is an integer of 1 to 15.]

Examples of the compound (a3) having a hydroxyl group and a (meth)acryloyl group include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol (meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane (meth)acrylate, ditrimethylolpropane di(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, etc. In addition, (poly)oxyalkylene modified compounds in which a (poly)oxyalkylene chain such as a (poly)oxyethylene chain, a (poly)oxypropylene chain, or a (poly)oxytetramethylene chain is introduced into the molecular structure of the various hydroxyl group-containing (meth)acrylate compounds, and lactone modified compounds in which a (poly)lactone structure is introduced into the molecular structure of the various hydroxyl group-containing (meth)acrylate compounds can also be used. These hydroxyl group-containing (meth)acrylate compounds can be used alone or in combination of two or more.

The content of the urethane resin (A) is preferably in the range of 3 to 50 mass % of the solid content of the curable resin composition of the present invention, and more preferably in the range of 20 to 40 mass %, since a curable resin composition having a low viscosity and capable of forming a cured product having excellent mechanical properties can be obtained.

The method for producing the urethane resin (A) is not particularly limited, and any method may be used. For example, the urethane resin (A) may be produced by a method in which all of the reaction raw materials containing the polyether polyol (a1), the polyisocyanate (a2), and the compound having a hydroxyl group and a (meth)acryloyl group (a3) are reacted at once, or the reaction raw materials may be reacted sequentially. In addition, since a curable resin composition that can form a cured product having low viscosity and excellent mechanical properties is obtained, it is preferable that the equivalent ratio (OH/NCO) of the total of the hydroxyl groups (OH) of the polyether polyol (a1) and the compound having a hydroxyl group and a (meth)acryloyl group (a3) to the isocyanate group (NCO) of the polyisocyanate (a2) is in the range of 0.9/1 to 1/0.9, and more preferably 1/1.

In the production of the urethane resin (A), for example, dibutyltin laurate, dibutyltin acetate, etc. can be used as a catalyst, and the resin can be produced under the conditions of a typical urethane reaction. If necessary, a solvent such as ethyl acetate, butyl acetate, methyl isobutyl ketone, toluene, xylene, etc., or a radical polymerizable monomer that does not contain a site that reacts with isocyanate and does not contain a hydroxyl group or an amino group, etc., can also be used as a solvent.

Examples of the monofunctional (meth)acrylate compound (B1) include phenoxyethyl (meth)acrylate, phenoxybenzyl (meth)acrylate, cyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, cyclohexylmethyl (meth)acrylate, cyclohexylethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dipropylene glycol mono(meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, isononyl (meth)acrylate, benzyl (meth)acrylate, phenylbenzyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethoxyethoxy diethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylmethoxy (meth)acrylate, 2-ethylethoxy (meth)acrylate, 2-ethylbutoxy (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, butoxydiethylene glycol (meth)acrylate, butoxytriethylene glycol ethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, (meth)acryloylmorpholine 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, glycidyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, dicyclopentenyl (meth)acrylate, Examples of the monofunctional (meth)acrylate include dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 3,4-epoxycyclohexylmethyl methacrylate, cyclic trimethylolpropane formal (meth)acrylate, 1-adamantyl (meth)acrylate, 2-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and N-(meth)acryloyloxyethylhexahydrophthalimide. These monofunctional (meth)acrylate compounds can be used alone or in combination of two or more. Among these, a compound having a glass transition temperature (hereinafter abbreviated as "Tg") of 50°C or higher of the polymer of a monofunctional (meth)acrylate compound is preferred, since it can produce a curable resin composition that has low viscosity and can form a cured product with excellent mechanical properties. Among these, a (meth)acrylate compound having a cyclic structure such as a condensed polycyclic structure or a heterocyclic structure is preferred, and further, acryloylmorpholine (Tg: 145°C), isobornyl acrylate (Tg: 94°C), isobornyl methacrylate (Tg: 180°C), dicyclopentenyl acrylate (Tg: 120°C), dicyclopentanyl acrylate (Tg: 120°C), dicyclopentanyl methacrylate (Tg: 175°C), N-acryloyloxyethylhexahydrophthalimide (Tg: 56°C) is preferred, and acryloylmorpholine is particularly preferred.

When two or more of the monofunctional (meth)acrylate compounds (B1) are used in combination, it is preferable that the Tg of the copolymer of the two or more monofunctional (meth)acrylate compounds is 50°C or higher.

Examples of the bifunctional (meth)acrylate compound (B2) include 1,6-hexanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-modified 1,6-hexanediol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate, and propylene oxide-modified neopentyl glycol di(meth)acrylate. di(meth)acrylate, tripropylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, ethylene oxide modified di(meth)acrylate of bisphenol A, propylene oxide modified di(meth)acrylate of bisphenol A, ethylene oxide modified di(meth)acrylate of bisphenol F, tricyclodecane dimethanol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol Di(meth)acrylate, propylene oxide modified tri(meth)acrylate of glycerin, 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, ethylene oxide modified di(meth)acrylate of bisphenoxyethanol fluorene, polytetramethylene glycol di(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, phenoxyethylene glycol (meth)acrylate, stearyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, trifluoroethyl (meth)acrylate 3-methyl-1,5 pentaerythritol Examples of the bifunctional (meth)acrylate include tandiol di(meth)acrylate, 2,3-[(meth)acryloyloxymethyl]norbornane, 2,5-[(meth)acryloyloxymethyl]norbornane, 2,6-[(meth)acryloyloxymethyl]norbornane, 1,3-adamantyl di(meth)acrylate, 1,3-bis[(meth)acryloyloxymethyl]adamantane, tris(hydroxyethyl)isocyanuric acid di(meth)acrylate, and 3,9-bis[1,1-dimethyl-2-(meth)acryloyloxyethyl]-2,4,8,10-tetraoxospiro[5.5]undecane. These bifunctional (meth)acrylate compounds can be used alone or in combination of two or more. Among these, a bifunctional (meth)acrylate compound having a polymer Tg of 50° C. or higher is preferred, since a curable resin composition capable of forming a cured product having low viscosity and excellent mechanical properties can be obtained. Among these, dipropylene glycol diacrylate (Tg: 102°C) and tricyclodecane dimethanol diacrylate (Tg: 110°C) are more preferred.

When two or more types of the bifunctional (meth)acrylate compounds (B2) are used in combination, it is preferable that the Tg of the copolymer of the two or more types of bifunctional (meth)acrylate compounds is 50°C or higher.

The monofunctional (meth)acrylate compound (B1) and the bifunctional (meth)acrylate compound (B2) can also be used in combination. In this case, it is preferable that the Tg of the copolymer of the (meth)acrylate compounds used in combination is 50°C or higher.

Furthermore, to the extent that the effects of the present invention are not impaired, the monofunctional (meth)acrylate compound (B1) and/or the bifunctional (meth)acrylate compound (B2) can be used in combination with a trifunctional or higher functional (meth)acrylate compound, if necessary. In this case, it is also preferable that the Tg of the copolymer of the (meth)acrylate compound used in combination is 50°C or higher.

Examples of the trifunctional or higher (meth)acrylate compounds include trifunctional (meth)acrylates such as EO-modified glycerol acrylate, PO-modified glycerol triacrylate, pentaerythritol triacrylate, EO-modified phosphoric acid triacrylate, trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane triacrylate, (EO)- or (PO)-modified trimethylolpropane triacrylate, alkyl-modified dipentaerythritol triacrylate, and tris(acryloxyethyl)isocyanurate;

Tetrafunctional (meth)acrylates such as ditrimethylolpropane tetraacrylate, pentaerythritol ethoxy tetraacrylate, and pentaerythritol tetraacrylate;

Pentafunctional (meth)acrylates such as dipentaerythritol hydroxypentaacrylate and alkyl-modified dipentaerythritol pentaacrylate;

Examples include hexafunctional (meth)acrylates such as dipentaerythritol hexaacrylate. These trifunctional or higher (meth)acrylates can be used alone or in combination of two or more.

The curable resin composition of the present invention further contains a photopolymerization initiator. Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2'-dimethoxy-1,2-diphenylethan-1-one, diphenyl(2,4,6-trimethoxybenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, phenyl(2,4,6-trimethylbenzoyl)ethyl phosphinate, and polymeric TPO-L.

Examples of commercially available photopolymerization initiators include "Omnirad-1173", "Omnirad-184", "Omnirad-127", "Omnirad-2959", "Omnirad-369", "Omnirad-379", "Omnirad-907", "Omnirad-4265", "Omnirad-1000", "Omnirad-651", "Omnirad-TPO", "Omnirad-819", "Omnirad-2022", "Omnirad-2100", "Omnirad-754", "Omnirad-784", "Omnirad-500", "Omnirad-81", "Omnirad Examples include "TPO-L", "Omnipol TP" (manufactured by IGM), "Kayacure-DETX", "Kayacure-MBP", "Kayacure-DMBI", "Kayacure-EPA", "Kayacure-OA" (manufactured by Nippon Kayaku Co., Ltd.), "Bi-Cure-10", "Bi-Cure-55" (manufactured by Stouffer Chemical Co., Ltd.), "Trigonal P1" (manufactured by Akzo), "Sandray 1000" (manufactured by Sandoz Co., Ltd.), "Deep" (manufactured by Upjohn), "Quantacure-PDO", "Quantacure-ITX", "Quantacure-EPD" (manufactured by Ward Blenkinsop Co., Ltd.), and "Runtecure-1104" (manufactured by Runtec).

The amount of the photopolymerization initiator added is preferably in the range of 1 to 20% by mass in the curable resin composition.

If necessary, a photosensitizer can be added to the curable resin composition to improve its curability.

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

The curable resin composition of the present invention may also contain various additives, such as ultraviolet absorbers, antioxidants, polymerization inhibitors, silicon-based additives, fluorine-based additives, silane coupling agents, phosphate ester compounds, organic beads, inorganic fine particles, organic fillers, inorganic fillers, rheology control agents, defoamers, and colorants, as necessary.

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

Examples of the antioxidant 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 additives include polyorganosiloxanes having alkyl or phenyl groups, such as dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, fluorine-modified dimethylpolysiloxane copolymer, and amino-modified dimethylpolysiloxane copolymer, polydimethylsiloxane having polyether-modified acrylic groups, and polydimethylsiloxane having polyester-modified acrylic groups. These silicon-based additives can be used alone or in combination of two or more kinds.

The fluorine-based additives include, for example, the "Megaface" series manufactured by DIC Corporation. These fluorine-based additives can be used alone or in combination of two or more kinds.

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-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyl Vinyl-based silane coupling agents such as pyrtrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, special aminosilane, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatepropyltriethoxysilane, allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane;

Epoxy-based silane coupling agents such as diethoxy(glycidyloxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane;

Styrene-based silane coupling agents such as p-styryltrimethoxysilane;

(Meth)acryloxy-based silane coupling agents such as 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane;

Amino-based silane coupling agents such as 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, and N-phenyl-3-aminopropyltrimethoxysilane;

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-mercaptopropyltrimethoxysilane;

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

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

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

Examples of the organic beads include polymethyl methacrylate beads, polycarbonate beads, polystyrene beads, polyacrylic styrene beads, silicone beads, 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. These organic beads can be used alone or in combination of two or more types. In addition, the average particle size of these organic beads is preferably in the range of 1 to 10 μm.

Examples of the inorganic fine particles include fine particles of silica, alumina, zirconia, titania, barium titanate, antimony trioxide, etc. These inorganic fine particles can be used alone or in combination of two or more kinds. The average particle size of these 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 dispersion aid can be used. Examples of the dispersion aid include phosphate ester compounds such as isopropyl acid phosphate, triisodecyl phosphite, and ethylene oxide modified phosphate dimethacrylate. These dispersion aids can be used alone or in combination of two or more. Examples of commercially available dispersion aids include "Kayamar PM-21" and "Kayamar PM-2" manufactured by Nippon Kayaku Co., Ltd., and "Light Ester P-2M" manufactured by Kyoeisha Chemical Co., Ltd.

Examples of the organic filler include plant-derived solvent-insoluble substances such as cellulose, lignin, and cellulose nanofibers.

Examples of the inorganic filler include glass (particles), silica (particles), alumina silicate, talc, mica, aluminum hydroxide, alumina, calcium carbonate, carbon nanotubes, etc.

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

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

Examples of the colorant include pigments and dyes.

As the pigment, known and commonly used inorganic pigments or organic pigments 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, 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, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, azo pigments, etc. 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, benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes, perinone dyes, phthalocyanine dyes, triarylmethane dyes, etc. These dyes can be used alone or in combination of two or more.

The cured product of the present invention can be obtained by irradiating the curable resin composition with active energy rays. Examples of the active energy rays include ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. When ultraviolet rays are used as the active energy rays, irradiation may be performed in an inert gas atmosphere such as nitrogen gas, or in an air atmosphere in order to efficiently carry out the curing reaction by ultraviolet rays.

As a source of ultraviolet light, ultraviolet lamps are generally used 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, LEDs, etc.

The cumulative light amount of the active energy rays is not particularly limited, but is preferably 50 to 5,000 mJ/cm ² , and more preferably 300 to 1,000 mJ/cm ^2. When the cumulative light amount is within the above range, it is preferable because the occurrence of uncured portions can be prevented or suppressed.

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

Examples of the optical three-dimensional modeling method include the stereolithography (SLA) method, the digital light processing (DLP) method, and the inkjet method.

The stereolithography (SLA) method is a method in which a tank of liquid curable resin composition is irradiated with active energy rays such as laser beams at points, and the composition is cured layer by layer while the modeling stage is moved to create a three-dimensional object.

The digital light processing (DLP) method is a method in which a tank of liquid curable resin composition is irradiated with active energy rays from an LED or the like, and the composition is cured layer by layer while the modeling stage is moved to create a three-dimensional object.

The inkjet stereolithography method is a method in which minute droplets of a stereolithography curable resin composition are ejected from a nozzle to draw a predetermined pattern, and then irradiated with ultraviolet light to form a cured thin film.

Among these optical three-dimensional modeling methods, the DLP method is preferred because it allows for high-speed modeling using surfaces.

The DLP three-dimensional modeling method is not particularly limited as long as it is a method using a DLP optical modeling system, but the modeling conditions are such that the modeling accuracy of the three-dimensional object is good, and the layer pitch of the optical modeling 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 in the range of 1 to 100 mJ/cm ^2. Among them, since the modeling accuracy of the three-dimensional object is even better, it is preferable that the layer pitch of the optical modeling is in the range of 0.02 to 0.1 mm, 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 15 mJ/cm ² .

The three-dimensional object of the present invention has a high elastic modulus and excellent impact resistance, and can therefore be suitably used for, for example, automobile parts, aerospace-related parts, electrical and electronic parts, home appliances, building materials, interior decorations, jewelry, medical materials, etc.

The present invention will be specifically explained below with examples and comparative examples.

In this example, the number average molecular weight (Mn) was measured using gel permeation chromatography (GPC) under the following conditions:

Measuring device: Tosoh Corporation HLC-8220
Column: Tosoh Corporation guard column _HXL -H
+ Tosoh Corporation TSKgel G5000HXL
+ Tosoh Corporation TSKgel G4000HXL
+ Tosoh Corporation TSKgel G3000HXL
+ Tosoh Corporation TSKgel G2000HXL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40°C
Solvent Tetrahydrofuran
Flow rate: 1.0 ml/min. Standard: polystyrene Sample: 100 μl of a tetrahydrofuran solution containing 0.4% by mass of resin solids filtered through a microfilter

(Synthesis Example 1: Synthesis of polyester polyol (1))
262 parts by mass of ethylene glycol and 571 parts by mass of adipic acid were charged into a reaction vessel equipped with a stirrer, a condenser, and a thermometer. The mixture was reacted at 200 to 250° C. for 18 hours while stirring under a nitrogen stream to obtain polyester polyol (1). This polyester polyol (1) had a number average molecular weight (Mn) of 2,300, a weight average molecular weight (Mw) of 4,800, an acid value of 2.0 mgKOH/g, and a hydroxyl value of 49 mgKOH/g.

(Synthesis Example 2: Synthesis of urethane resin (A-1) having acryloyl group)
A 1-liter flask equipped with a stirrer, a gas inlet tube, a condenser, and a thermometer was charged with 267 parts by mass of isophorone diisocyanate, 1.6 parts by mass of tertiary butyl hydroxytoluene, 0.2 parts by mass of methoxyhydroquinone, and 0.2 parts by mass of dibutyltin diacetate, and the temperature was raised to 70°C. 391 parts by mass of polytetramethylene glycol (number average molecular weight 650) was charged in portions over 1 hour. After charging, the mixture was reacted at 70°C for 3 hours, and then 140 parts by mass of hydroxyethyl acrylate was added dropwise over 1 hour. After the dropwise addition, the reaction was continued at 70°C until the infrared absorption spectrum at 2250 cm ^-1 indicating the isocyanate group disappeared, and a urethane resin (A-1) having an acryloyl group was obtained.

(Synthesis Example 3: Synthesis of urethane resin (A-2) having acryloyl group)
A 1-liter flask equipped with a stirrer, a gas inlet tube, a condenser, and a thermometer was charged with 132 parts by mass of isophorone diisocyanate, 1.6 parts by mass of tertiary butyl hydroxytoluene, 0.2 parts by mass of methoxyhydroquinone, and 0.2 parts by mass of dibutyltin diacetate, and the temperature was raised to 70°C. 596 parts by mass of polytetramethylene glycol (number average molecular weight 2000) was charged in portions over 1 hour. After charging, the mixture was reacted at 70°C for 3 hours, and then 69 parts by mass of hydroxyethyl acrylate was added dropwise over 1 hour. After the dropwise addition, the reaction was continued at 70°C until the infrared absorption spectrum at 2250 cm ^-1 indicating the isocyanate group disappeared, and a urethane resin (A-2) having an acryloyl group was obtained.

(Synthesis Example 4: Synthesis of urethane resin (A-3) having acryloyl group)
A 1-liter flask equipped with a stirrer, a gas inlet tube, a condenser, and a thermometer was charged with 76 parts by mass of isophorone diisocyanate, 1.6 parts by mass of tertiary butyl hydroxytoluene, 0.2 parts by mass of methoxyhydroquinone, and 0.2 parts by mass of dibutyltin diacetate, and the temperature was raised to 70°C. 683 parts by mass of polytetramethylene glycol (number average molecular weight 4000) was charged in portions over 1 hour. After charging, the mixture was reacted at 70°C for 3 hours, and then 40 parts by mass of hydroxyethyl acrylate was added dropwise over 1 hour. After the dropwise addition, the reaction was continued at 70°C until the infrared absorption spectrum at 2250 cm ^-1 indicating the isocyanate group disappeared, and a urethane resin (A-3) having an acryloyl group was obtained.

(Synthesis Example 5: Synthesis of urethane resin (A-4) having acryloyl group)
A 1-liter flask equipped with a stirrer, a gas inlet tube, a condenser, and a thermometer was charged with 132 parts by mass of isophorone diisocyanate, 1.6 parts by mass of tertiary butyl hydroxytoluene, 0.2 parts by mass of methoxyhydroquinone, and 0.2 parts by mass of dibutyltin diacetate, and the temperature was raised to 70°C. 596 parts by mass of polypropylene glycol (number average molecular weight 2000) was charged in portions over 1 hour. After charging, the mixture was reacted at 70°C for 3 hours, and then 69 parts by mass of hydroxyethyl acrylate was added dropwise over 1 hour. After the dropwise addition, the reaction was continued at 70°C until the infrared absorption spectrum at 2250 cm ^-1 indicating the isocyanate group disappeared, and a urethane resin (A-4) having an acryloyl group was obtained.

(Synthesis Example 6: Synthesis of urethane resin (A-5) having acryloyl group)
In a 1-liter flask equipped with a stirrer, a gas inlet tube, a condenser, and a thermometer, 118 parts by mass of isophorone diisocyanate, 1.6 parts by mass of tertiary butyl hydroxytoluene, 0.2 parts by mass of methoxyhydroquinone, and 0.2 parts by mass of dibutyltin diacetate were added, and the temperature was raised to 70°C, and 620 parts by mass of polyester polyol (1) obtained in Synthesis Example 1 was added dropwise over 1 hour. After the addition, the mixture was reacted at 70°C for 3 hours, and then 62 parts by mass of hydroxyethyl acrylate was added dropwise over 1 hour. After the addition, the reaction was continued at 70°C until the infrared absorption spectrum at 2250 cm ^-1 indicating the isocyanate group disappeared, and a urethane resin (A-5) having an acryloyl group was obtained.

(Example 1: Preparation of curable resin composition (1))
Into a four-neck flask equipped with a stirrer, a thermometer, and a cooling tube, 30 parts by mass of the urethane resin (A-1) having an acryloyl group obtained in Synthesis Example 1 and 70 parts by mass of acryloylmorpholine ("ACMO" manufactured by KJ Chemicals) were charged, and the mixture was stirred at 60°C or less until uniformly dissolved, thereby obtaining a curable resin composition (1).

(Examples 2 to 9: Preparation of curable resin compositions (2) to (9))
Curable resin compositions (2) to (9) were obtained in the same manner as in Example 1, except that the urethane resin having an acryloyl group and the (meth)acrylate compound were changed to the compositions and amounts shown in Table 1.

(Comparative Examples 1 to 5: Preparation of Curable Resin Compositions (C1) to (C5))
Curable resin compositions (C1) to (C5) were obtained in the same manner as in Example 1, except that the polyurethane resin having an acryloyl group and the (meth)acrylate compound used in Example 1 were changed to the compositions and amounts shown in Table 1.

The following evaluations were carried out using the curable resin compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 5 above.

[Viscosity measurement]
The viscosity at 25° C. of the curable resin compositions obtained in each of the Examples and Comparative Examples was measured using an E-type viscometer (TV-22, manufactured by Toki Sangyo Co., Ltd.).

[Preparation of test specimens]
A dumbbell for tensile testing (based on ASTM D638 TYPE 1) and a test piece for Izod impact testing (based on ASTM D256) were produced using a stereolithography 3D printer (D-MEC Corporation's "ACCULAS BA-30S"). Next, the dumbbell for tensile testing and the test piece for Izod impact testing obtained by stereolithography were washed with isopropyl alcohol, dried at room temperature for 1 hour, and then post-cured by irradiating both sides with UV light (10,000 mJ/cm ² each) using a high-pressure mercury lamp to obtain test piece 1 (dumbbell for tensile testing) and test piece 2 (test piece for Izod impact testing).

[Method of measuring elastic modulus and elongation]
A tensile test was carried out using the test piece 1 in accordance with ASTM D638 with an autograph "AG-Xplus 100kN" (load cell 100kN, head speed 5mm/min, test piece width 10mm) manufactured by Shimadzu Corporation, to measure the elastic modulus and elongation.

[Method of measuring Izod impact strength (impact resistance)]
The Izod impact strength of the test piece 2 was measured with a "Universal Impact Tester" manufactured by Toyo Seiki Seisakusho Co., Ltd. in accordance with ASTM D256.

The compositions and evaluation results of the curable resin compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 5 are shown in Table 1.

Claims (4)

A curable resin composition comprising a urethane resin (A) having a (meth)acryloyl group, and a monofunctional (meth)acrylate compound (B1) and/or a bifunctional (meth)acrylate compound (B2),
The content of the urethane resin (A) is in the range of 3 to 50 mass% in the solid content of the curable resin composition,
the glass transition temperature of the polymer of the monofunctional (meth)acrylate compound (B1) and/or the bifunctional (meth)acrylate compound (B2) is 50° C. or higher;
The urethane resin (A) contains, as essential reaction raw materials, polytetramethylene glycol as the polyether polyol (a1), isophorone diisocyanate as the polyisocyanate (a2), and hydroxyethyl acrylate as the compound (a3) having a hydroxyl group and a (meth)acryloyl group;
The number average molecular weight (Mn) of the polyether polyol (a1) is 1,000 to 3,500;
the monofunctional (meth)acrylate compound (B1) is at least one selected from the group consisting of (meth)acryloylmorpholine, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, N-(meth)acryloyloxyethylhexahydrophthalimide, and phenoxyethyl (meth)acrylate;
the bifunctional (meth)acrylate compound (B2) is at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate and ethylene oxide-modified di(meth)acrylate of bisphenol A;
A curable resin composition used in digital light processing type stereolithography systems . A cured product which is a cured reaction product of the curable resin composition according to claim 1 . The cured product according to claim 2 , wherein the curing condition is irradiation with active energy rays. A three-dimensional object comprising the cured product according to claim 2 or 3 .