Material for three-dimensional photolithography and method for producing molded product

Abstract

To provide a material for three-dimensional photolithography with superior impact resistance and heat resistance even when using a stereolithography device and a secondary curing device with weak irradiation intensity.SOLUTION: A material for three-dimensional photolithography comprises: a urethane (meth)acrylate (A); a (meth)acrylate with an alicyclic skeleton (B) and a trifunctional or higher polyfunctional (meth)acrylate (C), where the urethane (meth)acrylate (A) has a weight average molecular weight of 5000 or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a material for three-dimensional optical molding that can be used to easily mold a molded article having high impact resistance and excellent heat resistance when cured, and to a method for producing a molded article using this material for three-dimensional optical molding. [Background technology]

[0002] One method for easily obtaining 3D objects is the 3D modeling method, in which 2D layers obtained by slicing 3D data are stacked one by one. Among them, the optical 3D modeling method, which uses photocurable materials that are cured by exposure to light such as energy rays, is widely used for creating models in the manufacturing stage because the dimensional accuracy of the objects obtained is high.

[0003] In the past, 3D modeling devices were large and expensive, and their users were limited, mainly for commercial use. However, in recent years, 3D modeling devices have become smaller and cheaper, making it easy for anyone to create 3D objects.

[0004] However, as the equipment becomes smaller, the output of the energy beam irradiation decreases, and the irradiation intensity weakens. For this reason, the hardening rate of the 3D object obtained by the optical 3D modeling method cannot be increased sufficiently by the 3D modeling equipment alone, and the mechanical properties such as impact resistance and heat resistance are inferior to those obtained when the object is completely hardened. For this reason, a method is used in which the mechanical properties are improved by secondary hardening using thermal drying or energy beam irradiation after the 3D object is modeled by the 3D modeling equipment.

[0005] Thermal drying has the disadvantages of requiring high-temperature, long-term drying to increase the curing rate, and the need to introduce a dryer. In addition, when using energy ray irradiation, a strong light irradiation device such as a high-pressure mercury lamp is used, which is difficult to introduce in terms of cost and space, and the number of users is limited.

[0006] From the viewpoint of allowing anyone to easily obtain a three-dimensional object with excellent mechanical properties, it is not preferable to use the above-mentioned secondary curing device, which is difficult to install. Therefore, it is preferable to use a secondary curing device that uses energy beam irradiation, which is generally available and easily available. However, these devices have a weak output of energy beam irradiation, and the curing rate does not increase sufficiently, so the mechanical properties of the three-dimensional object remain inferior.

[0007] For example, Patent Document 1 describes that it is preferable to use a multifunctional urethane acrylate having a low molecular weight of 700 to 1,300.

[0008] On the other hand, in Patent Document 2, a three-dimensional object is obtained by using a urethane resin (A) having a (meth)acryloyl group, and a monofunctional (meth)acrylate compound (B1) and / or a bifunctional (meth)acrylate compound (B2) with a high energy irradiation dose, and then a mercury lamp is used to obtain high physical properties. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2022-181279 A [Patent Document 2] JP 2021-102676 A Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in view of the above, and the inventors have found the following through their investigation of Patent Documents 1 and 2. In Patent Document 1, the impact resistance and heat resistance of a three-dimensional object obtained when a three-dimensional modeling device and a secondary curing device with low irradiation intensity were used were low. In Patent Document 2, the impact resistance of a three-dimensional object obtained when evaluated using a device with low irradiation intensity was low, and it was difficult to achieve both high levels of impact resistance and heat resistance simply by using an oligomer unit with a high weight-average molecular weight in combination with a monofunctional or bifunctional acrylate.

[0011] An object of the present invention is to provide a material for three-dimensional optical modeling that can produce a three-dimensional object having good impact resistance and heat resistance even when using a three-dimensional modeling device and a secondary curing device with low irradiation intensity. [Means for solving the problem]

[0012] As a result of extensive investigations aimed at solving the above problems, the inventors discovered that a material for three-dimensional optical modeling having specific components can solve these problems, and thus completed the present invention. That is, the present invention relates to the following.

[0013] [1] A material for three-dimensional optical modeling comprising a urethane (meth)acrylate (A), a monofunctional (meth)acrylate (B) having a ring skeleton, and a trifunctional or higher polyfunctional (meth)acrylate (C), wherein the weight average molecular weight of the urethane (meth)acrylate (A) is 5,000 or more.

[0014] [2] The material for three-dimensional optical modeling according to [1], further comprising a photopolymerization initiator (D).

[0015] [3] The three-dimensional optical shaping material according to [1] or [2], wherein the monofunctional (meth)acrylate (B) is at least one selected from the group consisting of N-(meth)acryloylmorpholine, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and phenyl (meth)acrylate.

[0016] [4] The material for three-dimensional optical shaping according to any one of [1] to [3], wherein the mass ratio of the urethane (meth)acrylate (A) to the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B) and the polyfunctional (meth)acrylate (C) is 30 mass% or more.

[0017] [5] The material for three-dimensional optical shaping according to any one of [1] to [4], wherein the mass ratio of the urethane (meth)acrylate (A) to the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B) and the polyfunctional (meth)acrylate (C) is 55 mass% or less.

[0018] [6] The material for three-dimensional optical modeling according to any one of [1] to [5], wherein the mass ratio of the monofunctional (meth)acrylate (B) to the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B) and the polyfunctional (meth)acrylate (C) is 65 mass% or less.

[0019] [7] The material for three-dimensional optical modeling according to any one of [1] to [6], wherein the ratio of the polyfunctional (meth)acrylate (C) to the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 5 mass% or more.

[0020] [8] The material for three-dimensional optical modeling according to any one of [1] to [7], wherein the ratio of the polyfunctional (meth)acrylate (C) to the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 30 mass% or less.

[0021] [9] The material for three-dimensional optical shaping according to any one of [1] to [3], wherein the mass ratio of the urethane (meth)acrylate (A) to the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 30 mass% or more and 55 mass% or less, the mass ratio of the monofunctional (meth)acrylate (B) is 40 mass% or more and 65 mass% or less, and the mass ratio of the polyfunctional (meth)acrylate (C) is 5 mass% or more and 30 mass% or less.

[0022]

[10] The material for three-dimensional optical modeling according to any one of [1] to [9], further comprising a polymerization inhibitor.

[0023]

[11] The material for three-dimensional optical shaping according to any one of [1] to

[10] , further comprising an ultraviolet absorber.

[0024] A method for producing a three-dimensional object, comprising the step of irradiating the material for three-dimensional optical modeling according to any one of [1] to

[11] with active energy rays. Effect of the Invention

[0025] According to the three-dimensional optical modeling material of the present invention, a three-dimensional optical modeling material can be obtained that can produce a three-dimensional object with good impact resistance and heat resistance even when using a three-dimensional modeling device or secondary curing device with low irradiation intensity. Therefore, by using the 3D photopolymerization material of the present invention, mechanical properties not available with conventional photocurable materials can be obtained, making it possible to apply the material to parts that could not be used due to insufficient strength. In addition, anyone can easily create 3D objects that can be used as actual parts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The present invention will be described in detail below, but the present invention is not limited to the following description, and can be modified in any manner without departing from the gist of the present invention. In this specification, when "~" is used with a numerical value or a physical property value before and after it, the values ​​before and after it are included. In this specification, the term "urethane (meth)acrylate" refers to either or both of urethane acrylate and urethane methacrylate. The same applies to "(meth)acrylate".

[0027] [3D stereolithography materials] The three-dimensional optical modeling material of the present invention comprises a urethane (meth)acrylate (A) (hereinafter, may be referred to as "component (A)"), a monofunctional (meth)acrylate having a ring skeleton (B) (hereinafter, may be referred to as "component (B)"), and a trifunctional or higher polyfunctional (meth)acrylate (C) (hereinafter, may be referred to as "component (C)"), characterized in that the urethane (meth)acrylate (A) has a weight average molecular weight of 5,000 or more.

[0028] The mechanism by which the present invention is effective is believed to be as follows. The three-dimensional optical modeling material of the present invention is a three-dimensional object obtained by copolymerizing and curing the polymerizable components including the components (A), (B) and (C) by irradiation with active energy rays. In this case, the inclusion of the component (A) can enhance heat resistance and impact resistance. Furthermore, by using the component (B) in combination, the heat resistance of the resulting molded article can be improved due to the ring structure in the molecule contained in the component (B). Furthermore, by using component (C) in combination with component (A), the heat resistance can be improved.

[0029] <Urethane (meth)acrylate (A)> The urethane (meth)acrylate (A) is a urethane (meth)acrylate having a weight average molecular weight of 5,000 or more. This urethane (meth)acrylate (A) is a polymerizable component, and is a component that contributes to achieving both heat resistance and impact resistance of a three-dimensional object obtained by using the three-dimensional optical modeling material of the present invention. In the present invention, the polymerizable component specifically refers to the urethane (meth)acrylate (A), the (meth)acrylate (B) having a ring skeleton, the trifunctional or higher polyfunctional (meth)acrylate (C), and other polymerizable components described below that are included as necessary, all of which have a (meth)acryloyl group and undergo a polymerization reaction by irradiation with ultraviolet light.

[0030] From the viewpoint of achieving both impact resistance and heat resistance, the urethane (meth)acrylate (A) preferably has a functional group number of 2 or more. In order not to decrease the impact resistance, the urethane (meth)acrylate (A) preferably has a functional group number of 15 or less, more preferably 12 or less.

[0031] In the present invention, the weight average molecular weight of the urethane (meth)acrylate (A) is 5,000 or more, more preferably 7,000 or more. On the other hand, the weight average molecular weight of the urethane (meth)acrylate (A) is usually preferably 20,000 or less, more preferably 15,000 or less. When the weight average molecular weight is equal to or more than the lower limit, the impact resistance of a three-dimensional object obtained by using the three-dimensional optical modeling material is good, and when the weight average molecular weight is equal to or less than the upper limit, the viscosity of the three-dimensional optical modeling material is low, and the handling property is good.

[0032] The weight average molecular weight of the urethane (meth)acrylate (A) can be determined by high performance liquid chromatography under the specific measurement conditions shown in the examples below.

[0033] Here, the urethane (meth)acrylate (A) is a mixture of polyol (a1) and isocyanate. (a2) can be obtained by reacting with a hydroxyl group-containing (meth)acrylate (a3).

[0034] (Polyol (a1)) Examples of the polyol (a1) include polyols such as neopentyl glycol, ethylene glycol, diethylene glycol, propylene glycol, 1,6-hexanediol, 1,4-butanediol, 1,9-nonanediol, 1,10-decanediol, 3-methylpentanediol, 2,4-diethylpentanediol, tricyclodecane dimethanol, 1,4-cyclohexane dimethanol, 1,2-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, cyclohexanediol, hydrogenated bisphenol A, trimethylolpropane, and pentaerythritol; polyether-modified polyols obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to these polyhydric alcohols; and polyether-modified polyols obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to these polyhydric alcohols; and polyether-modified polyols obtained by adding alkylene oxides such as ε-caprolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, and the like. polycaprolactone polyols obtained by reacting these polyhydric alcohols and polybasic acids with lactones such as ε-caprolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, and other caprolactone-modified polyester polyols obtained by reacting these polyhydric alcohols and polybasic acids with lactones such as ε-caprolactone, γ-butyrolactone, γ-valerolactone, and δ-valerolactone; polycarbonate diols obtained by transesterification of diols such as 1,6-hexanediol, 3-methylpentanediol, 2,4-diethylpentanediol, trimethylhexanediol, 1,4-butanediol, 1,5-pentanediol, and 1,4-cyclohexanediol with carbonates such as ethylene carbonate, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, and diphenyl carbonate; polybutadiene glycol;Castor oil, dehydrated castor oil, soybean oil with hydroxyl groups introduced, canola oil with hydroxyl groups introduced, palm oil with hydroxyl groups introduced, rapeseed oil with hydroxyl groups introduced, cardanol-derived polyols, polyester polyols, polycarbonate polyols, dicarboxylic acids derived from unsaturated fatty acids such as oleic acids, linoleic acids, linolenic acids, and erucic acids, and ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, etc. linear polyhydric alcohols having 2 to 20 carbon atoms, such as 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, and 1,20-eicosanediol; 1,2-butanediol, 1,3-butanediol, 2-methyl-1 Polyhydric alcohols having a branched chain and a carbon number of 4 to 40, such as 1,3-propanediol, 2-methyl-1,4-butanediol, 2-ethyl-1,6-hexanediol, 2,4-diethyl-1,5-pentanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, and dimer diol; polyhydric alcohols having a cyclic structure in the molecule and a carbon number of 4 to 20, such as 1,3-cyclohexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol; and polyester polyols which are polycondensates with polyhydric alcohols such as diethylene glycol, triethylene glycol, polytetramethylene ether glycol, and dimer diol. Among these, since the curing rate of the present composition is good, polyols such as neopentyl glycol, ethylene glycol, diethylene glycol, propylene glycol, 1,6-hexanediol, 1,4-butanediol, 1,9-nonanediol, 1,10-decanediol, 3-methylpentanediol, 2,4-diethylpentanediol, tricyclodecane dimethanol, 1,4-cyclohexane dimethanol, 1,2-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, cyclohexanediol, hydrogenated bisphenol A, trimethylolpropane, pentaerythritol, castor oil and dehydrated castor oil, soybean oil with hydroxyl groups introduced, rapeseed oil with hydroxyl groups introduced, palm oil with hydroxyl groups introduced, rapeseed oil with hydroxyl groups introduced, cardanol-derived polyols, polyester polyols, and polycarbonate polyols are preferred.

[0035] In addition, from the viewpoint of environmental impact, it is more preferable to use polyols synthesized from plant-derived raw materials, such as castor oil, dehydrated castor oil, soybean oil with hydroxyl groups introduced, rapeseed oil with hydroxyl groups introduced, palm oil with hydroxyl groups introduced, rapeseed oil with hydroxyl groups introduced, cardanol-derived polyols, polyester polyols, polycarbonate polyols, and the like.

[0036] (Isocyanate (a2)) The isocyanate (a2) is an isocyanate having at least two isocyanate groups.

[0037] As the isocyanate (a2), for example, those that have been conventionally used in the production of urethane (meth)acrylates can be used. As the isocyanate (a2), for example, aromatic polyisocyanates such as 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, etc.; ethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4 ... Examples of the polyisocyanates include aliphatic polyisocyanates such as trimethylhexamethylene diisocyanate, lysine diisocyanate, and lysine triisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexylene diisocyanate; aromatic aliphatic polyisocyanates such as xylylene diisocyanate and tetramethylxylylene diisocyanate; and biuret and allophanate forms of these polyisocyanates.

[0038] Among these, aliphatic diisocyanates such as 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, bis(4-isocyanatocyclohexyl)methane, 1,2-hydrogenated xylylene diisocyanate, 1,4-hydrogenated xylylene diisocyanate, hydrogenated tetramethylxylylene diisocyanate, norbornane diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate are preferred because they can improve the impact resistance of three-dimensional objects obtained using the three-dimensional optical modeling material.

[0039] In the synthesis of the urethane (meth)acrylate (A), one type of compound can be used alone as the isocyanate (a2), or two or more types of components can be used in combination.

[0040] (Hydroxyl group-containing (meth)acrylate (a3)) The hydroxyl group-containing (meth)acrylate (a3) ​​is a compound having a hydroxyl group and a (meth)acryloyloxy group. The hydroxyl group contained in the (a3) ​​component forms a urethane bond with the isocyanate group of the polyol (a1) or an intermediate compound having an isocyanate group obtained from the polyol (a1). The hydroxyl group-containing (meth)acrylate (a3) ​​may have any structure as long as it can introduce a (meth)acryloyloxy group into the urethane (meth)acrylate (A).

[0041] Examples of the hydroxyl group-containing (meth)acrylate (a3) ​​include (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, cyclohexane dimethanol mono (meth)acrylate, trimethylolpropane di (meth)acrylate, pentaerythritol tri (meth)acrylate, and glycerin di (meth)acrylate, and caprolactone adducts of these (meth)acrylates. Among these, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and glycerin di (meth)acrylate are preferred because they provide a urethane (meth)acrylate (A) with low viscosity. In the synthesis of the urethane (meth)acrylate (A), one type of compound can be used alone as the hydroxyl group-containing (meth)acrylate (a3), or two or more types can be used in combination.

[0042] The urethane (meth)acrylate (A) may be used alone or in combination of two or more kinds.

[0043] (Ratio of urethane (meth)acrylate (A)) The content of the urethane (meth)acrylate (A) in the three-dimensional optical modeling material of the present invention is preferably 30% to 55% by mass, more preferably 30% to 50% by mass, and even more preferably 30% to 45% by mass, based on the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate having a ring skeleton (B), and the polyfunctional (meth)acrylate (C). When the content of the urethane (meth)acrylate (A) is within the above range, the heat resistance and impact resistance of the resulting three-dimensional model are improved.

[0044] <(Meth)acrylate having a ring skeleton (B)> The (meth)acrylate (B) having a ring structure is a polymerizable component that contributes to the heat resistance of a three-dimensional object obtained by using the material for three-dimensional optical modeling of the present invention. In the present invention, the ring structure refers to a ring such as an alicyclic ring, a heterocyclic ring, an aromatic ring, or a non-aromatic ring.

[0045] Examples of the (meth)acrylate (B) having a ring skeleton include benzyl (meth)acrylate, cresol (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, 3,3,5-trimethylcyclohexyl acrylate, ethoxylated-o-phenylphenol acrylate, phenoxybenzyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethoxylated-o-phenylphenol acrylate, phenoxybenzyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethoxylated-o-phenylphenol acrylate, phenoxyethyl ... Examples of suitable acrylates include oxylated-o-phenylphenol (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, and (meth)acryloylmorpholine. Of the above compounds, (meth)acryloylmorpholine, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and phenyl (meth)acrylate are preferred because of their excellent heat resistance.

[0046] The (meth)acrylate (B) having a ring skeleton may be used alone or in combination of two or more kinds.

[0047] The content of the (meth)acrylate (B) having a ring skeleton in the three-dimensional optical modeling material of the present invention is preferably 40% by mass to 65% by mass, more preferably 40% by mass to 62% by mass, and even more preferably 40% by mass to 60% by mass, based on the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B) having a ring skeleton, and the polyfunctional (meth)acrylate (C). By having the content of the (meth)acrylate (B) having a ring skeleton within the above range, excellent heat resistance and modeling properties can be obtained.

[0048] <Trifunctional or higher multifunctional (meth)acrylate (C)> The tri- or higher functional polyfunctional (meth)acrylate (C) is a polymerizable component, and is a component that contributes to the heat resistance of a three-dimensional object obtained using the three-dimensional optical modeling material of the present invention.

[0049] Examples of the trifunctional or higher polyfunctional (meth)acrylate (C) include, but are not limited to, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerin tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, isocyanuric acid EO-modified triacrylate, (meth)acrylic acid esters of compounds in which alkylene oxide is added to polyhydric alcohols, and (meth)acrylic acid esters of alcohols having an alkylene oxide skeleton. Examples of the polyhydric alcohol include trimethylolpropane, glycerin (including polyglycerin), pentaerythritol, ditrimethylolpropane, dipentaerythritol, and the like, and these may further have any desired substituent.

[0050] The alkylene oxide is preferably, for example, an alkylene oxide having 2 to 18 carbon atoms. More preferably, it is an alkylene oxide having 2 to 8 carbon atoms, and examples thereof include, but are not limited to, ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, trimethylethylene oxide, tetramethylene oxide, tetramethylethylene oxide, butadiene monoxide, octylene oxide, and styrene oxide. Among them, it is preferable to use an alkylene oxide having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, and butylene oxide, and particularly preferable are ethylene oxide and propylene oxide, and most preferable is ethylene oxide. The alkylene oxides may be used alone or in combination of two or more.

[0051] The tri- or higher functional polyfunctional (meth)acrylate (C) may be used alone or in combination of two or more kinds.

[0052] (Content of trifunctional or higher polyfunctional (meth)acrylate (C)) The content of the trifunctional or more polyfunctional (meth)acrylate (C) in the three-dimensional optical modeling material of the present invention is preferably 5% by mass to 30% by mass, more preferably 5% by mass to 25% by mass, even more preferably 6% by mass to 20% by mass, and particularly preferably 7% by mass to 15% by mass, based on the total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B) having a ring skeleton, and the polyfunctional (meth)acrylate (C). By having the content of the trifunctional or more polyfunctional (meth)acrylate (C) within the above range, the impact resistance and heat resistance of the resulting three-dimensional model can be compatible.

[0053] [Photopolymerization initiator (D)] The photopolymerization initiator (D) (hereinafter sometimes referred to as "component (D)") is a component that generates radical species when irradiated with active energy rays, and promotes the curing of the material for three-dimensional optical modeling of the present invention.

[0054] The component (D) is not particularly limited as long as it generates radical species upon irradiation with active energy rays, and examples thereof include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-2-morpholino(4-thiomethylphenanthrenyl) and the like. acetophenones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone oligomer; benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone, o-benzoylbenzoic acid methyl, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3' ,4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanaminium bromide, (4-benzoylbenzyl)trimethylammonium chloride and other benzophenones; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-(3-dimethylthioxanthone, 1-chloro-4-propoxythioxanthone, 1-methyl-2-phenylpropanediol ... thioxanthones such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, ethylphenyl(2,4,6-trimethylbenzoyl)phosphinate, and the like, but are not limited to these.

[0055] The component (D) may be used alone or in combination of two or more types.

[0056] The content of component (D) in the three-dimensional optical modeling material of the present invention is preferably 0.1% by mass to 10% by mass, more preferably 0.3% by mass to 7% by mass, and even more preferably 0.5% by mass to 5% by mass, based on 100% by mass of the total of the polymerizable components. By having the content of component (D) within the above range, the desired three-dimensional object can be obtained with good accuracy by the three-dimensional optical modeling method, and a molded product having good impact resistance and heat resistance can be obtained.

[0057] <Other polymerizable components> The three-dimensional optical modeling material of the present invention may contain other polymerizable components (hereinafter referred to as "other polymerizable components") other than the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B) having a ring structure, and the polyfunctional (meth)acrylate (C) having three or more functional groups, as necessary. As the other polymerizable components, (meth)acryloyl group-containing monomers are preferable. As the (meth)acryloyl group-containing monomers, monofunctional (meth)acrylates not having a ring structure, bifunctional (meth)acrylates, etc. can be mentioned.

[0058] Specific examples of monofunctional (meth)acrylates not having a ring skeleton include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 7-amino-3,7-dimethyloctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl diethylene glycol (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, lauryl (meth)acrylate, and polyester mono(meth)acrylate.

[0059] Specific examples of bifunctional (meth)acrylates include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, tricyclodecane di(meth)acrylate, tricyclodecanediyldimethylene di(meth)acrylate, bisphenol A di(meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, bisphenol F di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polycarbonate di(meth)acrylate, or polycaprolactone adducts, polycarbonate adducts, polyepoxy di(meth)acrylates, polyester di(meth)acrylates, and the like.

[0060] These other polymerizable components may be used alone or in combination of two or more.

[0061] When the three-dimensional optical modeling material of the present invention contains other polymerizable components, the content ratio of the other polymerizable components is not particularly limited as long as it is within a range that does not impair the performance of the three-dimensional optical modeling material of the present invention; however, the content ratio is preferably 50 mass % or less, more preferably 30 mass % or less, and even more preferably 20 mass % or less, based on 100 mass % of all polymerizable components. By using other polymerizable components, it is possible to improve the heat resistance and impact resistance in addition to the moldability.

[0062] <Additives> The three-dimensional optical modeling material of the present invention may contain various additives such as ultraviolet absorbers, photocation initiators, polymerization inhibitors, photosensitizers, light stabilizers, heat stabilizers, antioxidants, release agents, lubricants, plasticizers, antistatic agents, flame retardants, flame retardant assistants, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, fluorescent agents, and chain transfer agents, as well as solvents such as organic solvents, within the scope of the present invention.

[0063] (UV absorber) Examples of ultraviolet absorbers include 2-[4-{(2-hydroxy-3-dodecyloxy-propyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-{(2-hydroxy-3-tridecyloxy-propyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl -Triazine compounds such as 4,6-{bis(2,4-dimethylphenyl)}-1,3,5-triazine, 2-[4-{(2-hydroxy-3-dodecyloxy-propyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-[4-{(2-hydroxy-3-tridecyloxy-propyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; 2,4-dihydrazine benzophenone compounds such as 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2,5-thiophenediylbis(5-tertiarybutyl-1,3-benzoxazole), and 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol; phenyl compounds; phenyl benzoate compounds such as phenyl salicylate, p-tert-butylphenyl salicylate, and p-(1,1,3,3-tetramethylbutyl)phenyl salicylate; phenyl salicylates and phenyl salicylate compounds such as 3-hydroxyphenyl benzoate and phenylene-1,3-dibenzoate; and oxalic acid anilide compounds such as 2-ethoxy-2'-ethyloxalanilide and 2-ethoxy-2'-dodecyloxalanilide. These may be used alone or in combination of two or more.

[0064] The ultraviolet absorber is an effective component for controlling the curing depth of the material for three-dimensional optical modeling of the present invention. When the three-dimensional optical shaping material of the present invention contains an ultraviolet absorber, the content ratio thereof is not particularly limited, but it is preferably 0.005% by mass to 1% by mass, and more preferably 0.01% by mass to 0.8% by mass, relative to 100% by mass of the three-dimensional optical shaping material of the present invention.

[0065] (Photocationic Initiator) As the photocationic initiator, that is, the polymerization initiator that generates cationic species by irradiation with active energy rays, iodonium (4-methylphenyl) [4- (2-methylpropyl) phenyl]-hexafluorophosphate is mentioned as a suitable photocationic initiator, but is not limited thereto. As for these photocationic initiators, one kind may be used alone, or two or more kinds may be used in combination.

[0066] (Polymerization inhibitor) Examples of the polymerization inhibitor include, but are not limited to, hydroquinone-based polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, hydroquinone monoethyl ether, hydroquinone monopropyl ether, hydroquinone monobutyl ether, hydroquinone monopentyl ether, hydroquinone monohexyl ether, hydroquinone monooctyl ether, and hydroquinone monoheptyl ether; benzoquinone-based polymerization inhibitors; and phenol-based polymerization inhibitors having a substituent such as 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. These polymerization inhibitors may be used alone or in combination of two or more.

[0067] The polymerization inhibitor functions as a polymerization suppressor during reaction or storage. When the material for three-dimensional optical shaping of the present invention contains a polymerization inhibitor, the content ratio thereof is preferably 0.1% by mass to 1.0% by mass with respect to 100% by mass of the material for three-dimensional optical shaping of the present invention.

[0068] (Photosensitizer) Examples of photosensitizers include, but are not limited to, benzophenone, 4,4-diethylaminobenzophenone, 1-hydroxycyclohexylphenyl ketone, p-dimethylaminobenzoic acid isoamyl, 4-dimethylaminobenzoic acid methyl, benzoin, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, 2,2-diethoxyacetophenone, o-benzoylbenzoic acid methyl, 2-hydroxy-2-methyl-1-phenylpropan-1-one, acylphosphine oxide, etc. These photosensitizers may be used alone or in combination of two or more. When the three-dimensional optical modeling material of the present invention contains a photosensitizer, the content is preferably 0.01% by mass to 10.00% by mass in 100% by mass of the three-dimensional optical modeling material of the present invention.

[0069] (Light stabilizer) The light stabilizer is not particularly limited as long as it does not significantly affect the properties of the obtained molded product, and examples thereof include 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentyl phenol, and the like. Benzotriazole compounds such as phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)]-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol, cyanoacrylate compounds such as ethyl 2-cyano-3,3-diphenylacrylate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, triazine compounds, benzophenone compounds such as octabenzone, 2,2'-4,4'-tetrahydrobenzophenone, etc., but are not limited thereto. Note that the light stabilizer may also function as a photosensitizer, in which case the photosensitizer may not be used. When the three-dimensional optical modeling material of the present invention contains a light stabilizer, the content is preferably 0.01% by mass to 10.00% by mass in 100% by mass of the three-dimensional optical modeling material of the present invention.

[0070] (Heat stabilizer) The heat stabilizer is not particularly limited as long as it does not significantly affect the properties of the resulting molded product, and examples thereof include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid side chain-having alkyl esters having 7 to 9 carbon atoms; 4,6-bis(octylthiomethyl)-o-cresol, 4,6- Examples of such compounds include, but are not limited to, hindered phenol compounds such as bis(dodecylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)]propionate, and hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate; phosphorus compounds such as tris(2,4-di-tert-butylphenyl)phosphite; and sulfur compounds such as dioctadecyl-3,3'-thiodipropionate. These heat stabilizers may be used alone or in combination of two or more kinds.

[0071] (Antioxidants) The antioxidant is not particularly limited as long as it does not significantly affect the properties of the obtained molded body, and examples of the antioxidant include hindered amine compounds such as bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate and bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, but are not limited to these. These antioxidants may be used alone or in combination of two or more.

[0072] In addition, fillers and the like may be added to the three-dimensional optical modeling material of the present invention in order to adjust the viscosity of the material or to impart functions to the material, as long as the performance of the resulting molded article is not significantly deteriorated. There are no particular limitations on the filler, and it is sufficient if it does not deteriorate the mechanical properties of the molded article.

[0073] (Filler) Examples of the filler include, but are not limited to, metal salts, metal oxides, polymer particles, inorganic fibers, organic fibers, carbon, etc. Examples of the metal oxide include, but are not limited to, silicon oxide, titanium oxide, aluminum oxide, etc. Examples of the polymer particles include, but are not limited to, acrylic particles, polystyrene particles, nylon particles, etc. Examples of the organic fibers include, but are not limited to, nylon fibers, cellulose nanofibers, etc.

[0074] If the amount of the filler added is too small, the effect of adding the filler cannot be fully obtained, and if the amount is too large, the viscosity of the material for three-dimensional optical modeling increases, resulting in poor modeling properties. Therefore, when the material for three-dimensional optical modeling of the present invention contains a filler, the content ratio of the filler is preferably within the range of 1.0% by mass to 50% by mass in 100% by mass of the material for three-dimensional optical modeling of the present invention.

[0075] The total amount of the various additives described above is preferably within the range of 0.01% by mass to 50.00% by mass based on 100% by mass of the material for three-dimensional optical modeling of the present invention.

[0076] (Organic solvent) The organic solvents include, but are not limited to, limonene, acetone, ethanol, isopropyl alcohol, and the like. These organic solvents may be used alone or in combination of two or more kinds. The amount of these organic solvents is preferably 10% by mass or less, more preferably 1% by mass or less, and even more preferably 0.1% by mass or less, based on 100% by mass of the 3D optical modeling material, and it is particularly preferable that they are substantially free of the material.

[0077] [Method of preparing material for three-dimensional photolithography] The method for preparing the material for three-dimensional optical modeling of the present invention is not particularly limited, but the simplest method is to weigh out all the materials and then stir them under heating (50 to 60° C.).

[0078] [Method of manufacturing the cured product] In the method of producing a three-dimensional object of the present invention by optical stereolithography using the three-dimensional stereolithography material of the present invention, any of the conventionally known optical stereolithography methods and devices can be used.

[0079] For example, a suitable optical stereolithography method is one in which a step of forming a thin film made of the above-mentioned three-dimensional optical modeling material of the present invention and a step of selectively irradiating the thin film with active energy rays to cure the thin film are repeated several times to laminate the cured thin films and produce a three-dimensional object of a desired shape. The cured product produced by the optical stereolithography method may be used as a product as it is, or may be further improved in mechanical properties, shape stability, etc. by secondary curing through irradiation with active energy rays or heating, and used as a product. According to the three-dimensional optical modeling material of the present invention, even if a three-dimensional modeling device and a secondary curing device with low energy beam irradiation intensity are used, a cured product with good heat resistance and impact resistance can be produced, and therefore it is suitable for use in a three-dimensional modeling device and a secondary curing device with low energy beam irradiation intensity.

[0080] Examples of the active energy rays include ultraviolet rays, electron beams, X-rays, radiation, and high frequency waves. Among them, ultraviolet rays having a wavelength of 300 to 430 nm are preferably used from an economical viewpoint. Specifically, active energy rays such as laser beams emitted from Ar lasers, He-Cd lasers, He-Ne lasers, ArF excimer lasers, CO2 lasers, Nd:YAG lasers, semiconductor lasers, Dye lasers, etc., and ultraviolet rays emitted from xenon lamps, metal halide lamps, mercury lamps, fluorescent lamps, etc. are preferred.

[0081] When forming each cured layer having a predetermined shape pattern by irradiating active energy rays onto a modeling surface made of the three-dimensional optical modeling material of the present invention, the cured layer may be formed by a pointillist or line drawing method using active energy rays focused into a point shape such as laser light, or a modeling method may be adopted in which the cured layer is formed by irradiating the modeling surface with active energy rays in a planar manner through a planar drawing mask formed by arranging a plurality of micro-optical shutters such as liquid crystal shutters or digital micromirror shutters (DMDs).

[0082] [Viscosity, impact resistance, heat resistance] <Viscosity> The E-type viscosity of the material for three-dimensional optical modeling of the present invention is preferably 3000 mPa·s or less at 25° C. If the E-type viscosity is 3000 mPa·s or less, modeling can be carried out without any problems in the optical stereolithography method.

[0083] <Impact resistance> The three-dimensional object obtained by forming and curing the material for three-dimensional stereolithography of the present invention using only active energy rays by a stereolithography method has an Izod impact value of preferably 40 J / m or more, more preferably 42 J / m or more, and even more preferably 44 J / m or more, as measured in accordance with ASTM D256. There is no particular upper limit to the Izod impact value, but it is usually 700 J / m or less.

[0084] <Heat resistance> Regarding a three-dimensional object obtained by using the three-dimensional optical modeling material of the present invention to model and harden the object using only active energy rays by an optical three-dimensional modeling method, in dynamic viscoelasticity measurement using a rheometer G-5000 (manufactured by UBM Corp.), the peak of tan δ measured at a vibration frequency of 10 Hz is preferably 100° C. or higher, more preferably 105° C. or higher, and even more preferably 110° C. or higher.

[0085] The specific method of shaping the molded body for measuring the dynamic viscoelasticity and the Izod impact value and the respective measurement methods are as shown in the Examples section below, and "shaping and curing only with active energy rays by optical 3D modeling" means that after shaping by optical 3D modeling, secondary curing is performed only with active energy rays without heating, even if secondary curing is performed.

[0086] [Application] The three-dimensional optical modeling material of the present invention can be used as it is as a modeling material for optical stereolithography. The three-dimensional optical modeling material of the present invention can also be used as a base material for a modeling material for optical stereolithography by mixing with a different material in order to exhibit special properties according to the purpose.

[0087] The three-dimensional optical modeling material of the present invention can be widely used in the field of optical three-dimensional modeling, and is not limited thereto. Representative application fields include models for verifying the appearance design during the design process, models for checking the functionality of parts, resin molds for producing casting molds, base models for producing metal molds, and direct molds for prototype metal molds. More specifically, the material can be applied to the production of models for precision parts, electric and electronic parts, furniture, architectural structures, automotive parts, various containers, castings, metal molds, mother molds, and models for processing. In particular, the material is extremely useful for parts that are exposed to high temperatures and require impact resistance, such as parts for automotive engines. In particular, the material for three-dimensional optical modeling of the present invention has good impact resistance and heat resistance, and can therefore be used for parts that require durability. EXAMPLES

[0088] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the examples described below as long as it does not deviate from the gist of the invention. The values ​​of various production conditions and evaluation results in the following examples are meant as preferred upper or lower limit values ​​in the embodiment of the present invention, and the preferred range may be a range defined by a combination of the above-mentioned upper or lower limit values ​​and the values ​​of the following examples or values ​​between the examples.

[0089] [Raw materials used] In the following Examples and Comparative Examples, the product names, compound names, and manufacturers of the raw materials used in the production of the materials for 3D optical modeling are as shown in Table 1 below.

[0090] [Table 1]

[0091] In this example, the weight average molecular weight of the urethane acrylate of the synthesis example is a weight average molecular weight calculated in terms of the molecular weight of standard polystyrene, and was measured using a high performance liquid chromatograph (Waters Corporation, "ACQUITY Advanced Polymer Chromatography (APC) System") with four columns in series: one ACQUITY APC XT 450, one ACQUITY APC XT 200, and two ACQUITY APC XT 45.

[0092] (Synthesis Example 1: Synthesis of urethane acrylate (A-1)) 275.5g of isophorone diisocyanate and 627.1g of Mw1000 polyol ether polyol (hydroxyl value 110.9mgKOH / g) were added to a flask equipped with an internal thermometer, a stirrer, and a cooling tube, and after heating to 60℃, 0.06g of 2,6-di-tert-butylcresol as a polymerization inhibitor and 0.02g of dibutyltin dilaurate as a reaction catalyst were added and reacted. Four hours after adding the catalyst, 23.6g of 1,3-propanediol (hydroxyl value 1474mgKOH / g) was added and reacted at 60℃. Four hours after the addition of 1,3-propanediol, 73.8 parts of 2-hydroxyethyl acrylate (HEA) was added as a hydroxyl group-containing (meth)acrylate and reacted at 60°C. The reaction was terminated when the residual isocyanate groups reached 0.1%, yielding a composition containing urethane acrylate (A-1) (weight average molecular weight (Mw): 9,200).

[0093] (Synthesis Example 2: Synthesis of urethane acrylate (A-2)) In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 269.7 g of isophorone diisocyanate and 422.9 g of Mw1000 castor oil (hydroxyl value 161.0 mgKOH / g) were added, and the mixture was heated to 60°C, after which 0.06 g of 2,6-di-tert-butylcresol as a polymerization inhibitor and 0.02 g of dibutyltin dilaurate as a reaction catalyst were added and reacted. Four hours after the addition of the catalyst, 307.4 parts of glycerin diacrylate (Aronix M-920) was added as a hydroxyl group-containing (meth)acrylate, and the reaction was stopped at 60°C when the residual isocyanate group reached 0.1%, to obtain a composition containing urethane acrylate (A-2) (weight average molecular weight (Mw); 13,400).

[0094] (Synthesis Example 3: Synthesis of urethane acrylate (A-3)) In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 166.26 g of isophorone diisocyanate and 246.16 g of polytetramethylene glycol (hydroxyl value 170.5 mg KOH / g) were added, and the mixture was heated to 65°C, followed by adding 0.025 g of dibutyltin dilaurate as a reaction catalyst to cause a reaction. Three hours after the addition of the catalyst, 87.58 g of hydroxyethyl acrylate, 1.00 g of 2,6-di-tert-butylcresol, and 0.13 g of methoxyhydroquinone were added and reacted at 60°C. The reaction was then terminated when the remaining isocyanate group became 0.1% or less, and a composition containing urethane acrylate (A-3) (weight average molecular weight (Mw); 3,600) was obtained.

[0095] (Synthesis Example 4: Synthesis of urethane acrylate (A-4)) In a flask equipped with an internal thermometer, a stirrer, and a cooling tube, 83.30 g of isophorone diisocyanate and 373.19 g of polytetramethylene glycol (hydroxyl value 57.3 mgKOH / g) were added, and the mixture was heated to 65°C, followed by adding 0.025 g of dibutyltin dilaurate as a reaction catalyst to cause a reaction. Three hours after the addition of the catalyst, 43.52 g of hydroxyethyl acrylate, 1.00 g of 2,6-di-tert-butylcresol, and 0.13 g of methoxyhydroquinone were added and reacted at 60°C. The reaction was then terminated when the remaining isocyanate group became 0.1% or less, and a composition containing urethane acrylate (A-4) (weight average molecular weight (Mw); 10,400) was obtained.

[0096] [Example 1] (1) Preparation of materials for 3D photolithography 40 g of the urethane acrylate (A-1) obtained in Synthesis Example 1, 30 g of N-acryloylmorpholine (product name: ACMO, manufactured by KJ Chemicals), 20 g of isobornyl acrylate (trade name: EBECRYL IBOA, company), 10 g of EO-modified di- and triacrylate of isocyanuric acid (di form: tri form = 12:88) (product name: Aronix M315, manufactured by Toagosei Co., Ltd.), and 2 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (trade name: Omnirad TPO H, manufactured by BASF) as a polymerization initiator were weighed, and the mixture was stirred at 50 to 60 °C until it became uniform to obtain a material for three-dimensional optical modeling.

[0097] (2) Preparation of Samples for Evaluation <a. Preparation of Samples for Impact Resistance (Izod Impact Test) Evaluation> Using a stereolithography apparatus (trade name: Elegoo Mars Pro3, manufactured by Elegoo), a prism with dimensions of 63.5 mm × 12.7 mm × 3.0 mm (= length × width × thickness) was fabricated in the length direction as a sample for impact resistance (Izod impact test) evaluation in accordance with ASTM D256. The fabrication conditions were set such that the thickness per layer was 100 μm, the irradiation time for the initial 5 layers was 20 seconds per layer, and thereafter the irradiation time per layer was set to 3 seconds. The obtained prism was irradiated with UV for 15 minutes using a secondary curing apparatus (trade name: Prusa CW1s, manufactured by Prusa) to obtain a sample for Izod impact test evaluation.

[0098] <b. Preparation of Samples for Heat Resistance (Dynamic Viscoelasticity) Evaluation> Using a stereolithography apparatus (trade name: Elegoo Mars Pro3, manufactured by Elegoo), a prism with dimensions of 70.0 mm × 10.0 mm × 1.0 mm (= length × width × thickness) was fabricated in the length direction as a sample for evaluating heat resistance (dynamic viscoelasticity). The fabrication conditions were set such that the thickness per layer was 100 μm, the irradiation time for the initial 5 layers was 20 seconds per layer, and thereafter the irradiation time per layer was set to 3 seconds. The obtained prism was irradiated with UV light for 15 minutes using a secondary curing apparatus (trade name: Prusa CW1s, manufactured by Prusa). Subsequently, the central portion of the above evaluation sample was cut out to a size of 25.0 mm × 5.0 mm × 1.0 mm (= length × width × thickness) to obtain a sample for dynamic viscoelasticity evaluation.

[0099] (3) Evaluation of the three-dimensional optical shaping material and the evaluation sample <A. Evaluation of formability> In the preparation of the evaluation samples in a. and b. above, the size of the obtained samples was confirmed and evaluated as follows. ○: Prisms of the set size were obtained in all cases. ×: Prisms of the set size were not obtained in one or both cases.

[0100] <B. Evaluation of impact resistance (Izod impact test)> The samples prepared as described in the preparation of the a. Izod evaluation samples were measured for the Izod impact value (unit: J / m) under the condition of 23°C in accordance with ASTM D256, and the impact resistance was evaluated according to the following criteria. ◎: 44 J / m or more ○: 40 J / m or more and less than 44 J / m ×: Less than 40 J / m

[0101] <C. Evaluation of heat resistance (dynamic viscoelasticity)> The dynamic viscoelasticity of the samples prepared as described in the preparation of the b. dynamic viscoelasticity evaluation samples was measured with a chuck distance of 20 mm and a vibration frequency of 10 Hz, and the heat resistance was evaluated according to the following criteria. ◎: The peak of tanδ is 110°C or higher ○: The peak of tanδ is 100°C or higher and less than 110°C ×: Peak of tan δ is less than 100°C

[0102] [Examples 2 to 7, Comparative Examples 1 to 6] The materials for three-dimensional optical modeling were prepared and evaluated in the same manner as in Example 1, except that the raw materials shown in Table 1 were weighed out as shown in Table 2.

[0103] The evaluation results of Examples 1 to 7 and Comparative Examples 1 to 6 are shown in Table 2.

[0104] [Table 2]

[0105] As is clear from the above results, in Examples 1 to 7 in which the present invention was applied, cured products having good heat resistance and impact resistance were produced. In contrast, Comparative Examples 1 to 3, which do not contain the component (A) having a weight average molecular weight of 5000 or more, were inferior in impact resistance. In Comparative Examples 4 and 5, which did not contain the component (C) in the polymerizable components, both heat resistance and impact resistance could not be achieved. In Comparative Example 6, which did not contain component (C), no molding was possible. [Industrial Applicability]

[0106] The three-dimensional optical modeling material of the present invention is suitable as a material for forming a three-dimensional optical model in optical modeling applications.

Claims

1. A material for three-dimensional optical modeling comprising a urethane (meth)acrylate (A), a monofunctional (meth)acrylate (B) having a ring skeleton, and a trifunctional or higher polyfunctional (meth)acrylate (C), wherein the urethane (meth)acrylate (A) has a weight average molecular weight of 5,000 or more.

2. The material for three-dimensional optical shaping according to claim 1 , further comprising a photopolymerization initiator (D).

3. 3. The three-dimensional optical shaping material according to claim 1 or 2, wherein the monofunctional (meth)acrylate (B) comprises at least one selected from the group consisting of N-(meth)acryloylmorpholine, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and phenyl (meth)acrylate.

4. 3. The material for three-dimensional optical shaping according to claim 1, wherein a mass ratio of the urethane (meth)acrylate (A) to a total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 30 mass% or more.

5. 3. The material for three-dimensional optical shaping according to claim 1, wherein a mass ratio of the urethane (meth)acrylate (A) to a total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 55 mass% or less.

6. 3. The material for three-dimensional optical shaping according to claim 1, wherein a mass ratio of the monofunctional (meth)acrylate (B) to a total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 65 mass% or less.

7. 3. The material for three-dimensional optical shaping according to claim 1, wherein a ratio of the polyfunctional (meth)acrylate (C) to a total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 5 mass% or more.

8. 3. The material for three-dimensional optical shaping according to claim 1, wherein a ratio of the polyfunctional (meth)acrylate (C) to a total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 30 mass% or less.

9. 3. The three-dimensional optical modeling material according to claim 1, wherein a mass ratio of the urethane (meth)acrylate (A) to a total amount of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the polyfunctional (meth)acrylate (C) is 30 mass% or more and 55 mass% or less, a mass ratio of the monofunctional (meth)acrylate (B) is 40 mass% or more and 65 mass% or less, and a ratio of the polyfunctional (meth)acrylate (C) is 5 mass% or more and 30 mass% or less.

10. The material for three-dimensional optical shaping according to claim 1 or 2, further comprising a polymerization inhibitor.

11. The material for three-dimensional optical shaping according to claim 1 or 2, further comprising an ultraviolet absorbing agent.

12. A method for producing a three-dimensional object, comprising the step of irradiating the material for three-dimensional optical modeling according to claim 1 or 2 with active energy rays.

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