Resin composition for photopolymerization, modeling material composition, photocured product thereof, and photopolymerization composition set

Abstract

The present invention pertains to a photo fabrication resin composition containing a polymerizable compound, wherein the polymerizable compound includes: at least one polyfunctional ethylenically-unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure; and at least one polyfunctional ethylenically-unsaturated monomer (C) having an isocyanurate ring structure, the contained amount of the monomer (C) is 5-80 parts by mass with respect to 100 parts by mass of the photo fabrication resin composition, the contained amount of a monofunctional ethylenically-unsaturated monomer (A) is less than 70 parts by mass with respect to 100 parts by mass of the photo fabrication resin composition.

Description

[Technical field]

[0001] This patent application claims priority under the Paris Convention to Japanese Patent Application No. 2019-166550 (filing date: September 12, 2019), the entire contents of which are incorporated herein by reference. The present invention relates to a stereolithography resin composition used in a stereolithography method, and a photocured product of the stereolithography resin composition.The present invention also relates to a model material composition used in a material jet stereolithography method, and a photocured product of the model material composition, as well as a material jet stereolithography composition set containing the model material composition. [Background technology]

[0002] Conventionally, a method for producing a three-dimensional object by continuously forming a cured layer having a predetermined shape by irradiating a photocurable resin composition with light such as ultraviolet light is widely known. Examples of the photo-lithography method include a liquid tank photopolymerization method in which a liquid photocurable resin is irradiated with light such as ultraviolet light to be cured and laminated one by one, and a material jet method (inkjet method) photo-lithography method (hereinafter also referred to as "material jet photo-lithography") in which a photocurable resin composition is discharged from a material jet nozzle, and immediately thereafter irradiated with light such as ultraviolet light to cure the resin composition, thereby laminating cured layers having a predetermined shape to produce a three-dimensional object. Among them, the material jet photo-lithography method has been widely noticed as a modeling method that can be realized by a small modeling device (3D printer) that can freely produce a three-dimensional object based on CAD (Computer Aided Design) data. As an example of a model material composition that can be used in such a material jet stereolithography method, Patent Document 1 discloses a model material composition that contains a monofunctional ethylenically unsaturated monomer (A) that has no urethane group, a polyfunctional ethylenically unsaturated monomer (B) that has no urethane group, an ethylenically unsaturated monomer (C) that has a urethane group, and a photopolymerization initiator (D), and in which the homopolymers of the monomers (A) and (B) each have a predetermined glass transition temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-20474 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, photocured products of stereolithography resin compositions used in stereolithography, particularly photocured products of modeling material compositions used in material jet stereolithography (hereinafter also referred to as "modeling materials"), are expected to be used in high temperature environments exceeding 100°C, for example, as printed circuit board members for electronic devices. For example, as described in Patent Document 1, methods for improving the heat resistance of modeling materials have been proposed, but the heat resistance in more severe temperature environments has not always been sufficient. For this reason, when exposed to a high temperature environment, dimensional changes due to thermal expansion tend to occur, and it has been found that in order to apply the material to the above-mentioned applications, a high heat resistance that is less likely to cause dimensional changes due to thermal expansion at higher temperatures than has been conventionally required is required.

[0005] Therefore, an object of the present invention is to provide a resin composition for stereolithography that has high heat resistance, is resistant to thermal expansion even in high-temperature environments, and can form a photocured product that can maintain high dimensional stability. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the above problems and have completed the present invention.

[0007] That is, the present invention provides the following preferred embodiments. [1] A resin composition for stereolithography, Contains a polymerizable compound, The polymerizable compound is At least one polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure; and At least one polyfunctional ethylenically unsaturated monomer (C) having an isocyanurate ring structure Including, The content of the monomer (C) is 5 to 80 parts by mass relative to 100 parts by mass of the resin composition for stereolithography, and the content of the monofunctional ethylenically unsaturated monomer (A) is less than 70 parts by mass relative to 100 parts by mass of the resin composition for stereolithography. [2] The stereolithography resin composition according to [1], wherein the polymerizable compound further contains at least one monofunctional ethylenically unsaturated monomer (A). [3] The stereolithography resin composition according to [1] or [2], wherein the content of the monomer (A) is 59 parts by mass or less per 100 parts by mass of the stereolithography resin composition. [4] The stereolithography resin composition according to any one of [1] to [3], wherein the content of the monomer (B) is 5 to 65 parts by mass per 100 parts by mass of the stereolithography resin composition. [5] A model material composition for use in a material jet stereolithography method, comprising: 19 to 59 parts by mass of at least one monofunctional ethylenically unsaturated monomer (A); 5 to 50 parts by mass of at least one polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure; and At least one polyfunctional ethylenically unsaturated monomer (C) having an isocyanurate ring structure, 5 to 50 parts by mass A model material composition comprising: [6] The model material composition according to [5], wherein the at least one polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure is a polyfunctional ethylenically unsaturated monomer having an alicyclic structure. [7] The model material composition according to [5] or [6], wherein the monofunctional ethylenically unsaturated monomer (A) has a homopolymer glass transition temperature Tg of 80° C. or higher. [8] The model material composition according to any one of [5] to [7], wherein the polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure has a linear expansion coefficient of 200 ppm or less, measured at a temperature equal to or lower than the glass transition temperature of the homopolymer according to JIS K 7197. [9] The model material composition according to any one of [5] to [8], wherein the polyfunctional ethylenically unsaturated monomer (C) having an isocyanurate ring structure has a linear expansion coefficient of 200 ppm or less, measured at a temperature equal to or lower than the glass transition temperature of the homopolymer according to JIS K 7197.

[10] The model material composition according to any one of the above [5] to [9], further comprising 1 to 15 parts by mass of a photopolymerization initiator (D) relative to 100 parts by mass of the model material composition.

[11] The model material composition according to any one of the above [5] to

[10] , further comprising 0.005 to 3 parts by mass of a surface conditioner (E) relative to 100 parts by mass of the model material composition.

[12] The model material composition according to any one of [5] to

[11] above, further comprising 0.05 to 3 parts by mass of a storage stabilizer (F) relative to 100 parts by mass of the model material composition.

[13] A photocured product of the stereolithography resin composition according to any one of the above [1] to [4] or the model material composition according to any one of the above [5] to

[12] .

[14] The photocured product according to

[13] above, having a linear expansion coefficient measured at or below the glass transition temperature in accordance with JIS K 7197 of 150 ppm or less.

[15] A material jet stereolithography composition set comprising the model material composition according to any one of [5] to

[12] above and a supporting material composition used together with the model material composition. Effect of the Invention

[0008] According to the present invention, it is possible to provide a resin composition for photopolymerization that can be used to form a photocured product by photopolymerization, which has high heat resistance, is resistant to thermal expansion even in high-temperature environments, and can maintain high dimensional stability, and the photocured product can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail, but the present invention is not limited to these.

[0010] <Resin composition for stereolithography> The stereolithography resin composition of the present invention is a composition used in a stereolithography method, and forms a photocured product by photocuring. Here, the stereolithography method includes methods using methods such as liquid tank photopolymerization methods (SLA, DLP, LCD) and material jet method (MJM). In the present invention, the "stereolithography resin composition" means a composition used in a stereolithography method, and the "photocured product" means a photocured product of the stereolithography resin composition. In this specification, the explanation of each component, characteristic, etc. of the stereolithography resin composition also applies to the model material composition used in the material jet stereolithography method, unless otherwise specified. Similarly, the explanation of each component, characteristic, etc. of the photocured product in this specification also applies to the model material, which is a photocured product of the model material composition, unless otherwise specified.

[0011] The stereolithography resin composition of the present invention contains a polymerizable compound, and the polymerizable compound contains at least one polyfunctional ethylenically unsaturated monomer (B) (hereinafter also referred to as "monomer B") having a ring structure other than an isocyanurate ring structure and at least one polyfunctional ethylenically unsaturated monomer (C) (hereinafter also referred to as "monomer C") having an isocyanurate ring structure. In the present invention, the ethylenically unsaturated monomer is a polymerizable monomer having at least one ethylenic double bond in the molecule that has the property of being cured by energy rays. The monofunctional ethylenically unsaturated monomer is a polymerizable monomer having one ethylenic double bond in the molecule, and the polyfunctional ethylenically unsaturated monomer is a polymerizable monomer having two or more ethylenic double bonds in the molecule.

[0012] [Polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure (monomer B)] The stereolithography resin composition of the present invention is easy to suppress an excessive increase in viscosity of the stereolithography resin composition and easy to improve the dimensional stability of the obtained photocured product by containing the monomer B. In particular, by containing the monomer B in combination with the monomer C described below, the thermal expansion of the obtained photocured product in a high-temperature environment is suppressed, and the dimensional stability is easy to improve.

[0013] Examples of the monomer B include polyfunctional ethylenically unsaturated monomers having an alicyclic structure or an aromatic hydrocarbon ring structure. These monomers may be used alone or in combination of two or more. In this specification, the alicyclic structure refers to an aliphatic cyclic structure in which carbon atoms are bonded in a ring shape.

[0014] Examples of the polyfunctional ethylenically unsaturated monomer having an alicyclic structure include polyfunctional (meth)acrylates having an alicyclic structure. Examples of the polyfunctional (meth)acrylates having an alicyclic structure include di- or tri(meth)acrylates having an alicyclic structure, specifically, cyclohexane dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, etc. In this specification, "(meth)acrylate" refers to both or either of acrylate and methacrylate.

[0015] Examples of the polyfunctional ethylenically unsaturated monomer having an aromatic hydrocarbon ring structure include bisphenol A ethylene oxide adduct di(meth)acrylate, and bisphenol A propylene oxide adduct di(meth)acrylate.

[0016] Among these polyfunctional ethylenically unsaturated monomers, polyfunctional ethylenically unsaturated monomers having an alicyclic structure are preferred from the viewpoint of dimensional stability. A preferred polyfunctional ethylenically unsaturated monomer having an alicyclic structure is a di- or tri(meth)acrylate having an alicyclic structure, more preferably a di- or tri(meth)acrylate having 5 to 30 carbon atoms. alicyclicPreferably, the monomer B is a di- or tri(meth)acrylate having an alicyclic structure having 6 to 20 carbon atoms, more preferably a di- or tri(meth)acrylate having an alicyclic structure having 8 to 15 carbon atoms. When the monomer B is a polyfunctional ethylenically unsaturated monomer having an alicyclic structure, it is easy to obtain a stereolithography resin composition that is resistant to thermal expansion and can form a photocured product with high dimensional stability even in a high temperature environment. In addition, it is easier to suppress an excessive increase in viscosity of the stereolithography resin composition than when the monomer B is a polyfunctional ethylenically unsaturated monomer having an aromatic hydrocarbon ring.

[0017] The linear expansion coefficient of the homopolymer of the monomer B is preferably 200 ppm or less. The linear expansion coefficient is more preferably 150 ppm or less, further preferably 130 ppm or less, particularly preferably 120 ppm or less, and particularly preferably 100 ppm or less. The lower limit is not particularly limited and may be 0 ppm, since the lower the linear expansion coefficient, the higher the thermal expansion suppression effect tends to be. When the linear expansion coefficient is equal to or less than the upper limit, the thermal expansion of the photocured product obtained from the stereolithography resin composition in a high-temperature environment is suppressed, and the dimensional stability of the photocured product is easily improved. The linear expansion coefficient can be measured in a temperature range below the glass transition temperature, for example, from room temperature to the glass transition temperature of the homopolymer minus 30°C, using a homopolymer of the monomer B as a test piece according to JIS K 7197. In detail, the linear expansion coefficient can be measured, for example, by the method described in the Examples. For example, the homopolymer of the monomer B can be measured by adding a photopolymerization initiator to the monomer B, and then irradiating the photocured product with an integrated light amount of 500 mJ / cm 2 with a metal halide lamp. 2 The resin is then cured by exposure to ultraviolet light.

[0018] The content of the monomer B is preferably 5 to 65 parts by mass relative to 100 parts by mass of the stereolithography resin composition. When the content of the monomer B is equal to or more than the lower limit, the dimensional stability of the photocured product obtained is easily increased, and when the content is equal to or less than the upper limit, the viscosity of the stereolithography resin composition is easily adjusted to a viscosity suitable for stereolithography by suppressing an excessive increase in the viscosity. In addition, from the viewpoint of dimensional stability, the content of the monomer B is preferably equal to or more than 10 parts by mass, more preferably equal to or more than 15 parts by mass, and even more preferably equal to or more than 20 parts by mass relative to 100 parts by mass of the stereolithography resin composition. In addition, from the viewpoint of the viscosity of the stereolithography resin composition, the content is preferably equal to or less than 60 parts by mass, more preferably equal to or less than 50 parts by mass, and even more preferably equal to or less than 45 parts by mass.

[0019] In one embodiment of the present invention, when the stereolithography resin composition is a model material composition used in a material jet stereolithography method, the content of the monomer B suitable for the material jet stereolithography method is 5 to 50 parts by mass relative to 100 parts by mass of the model material composition. If the content of the monomer B is less than the lower limit, it is difficult to impart sufficiently high dimensional stability to the obtained model material, and if it exceeds the upper limit, the viscosity of the model material composition is likely to increase excessively. In addition, from the viewpoint of dimensional stability, the content of the monomer B is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and even more preferably 20 parts by mass or more relative to 100 parts by mass of the model material composition. In addition, from the viewpoint of viscosity of the model material composition, it is preferably 45 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less.

[0020] [Polyfunctional ethylenically unsaturated monomer (C) having an isocyanurate ring structure (monomer C)] By including the monomer C, the dimensional stability of the photocured product obtained in a high temperature environment can be improved. This is believed to be because the inclusion of a polyfunctional monomer having a rigid structure, an isocyanurate ring structure, can suppress the vibration of molecules in the photocured product obtained from the photopolymerization resin composition. The effect of improving the dimensional stability of such a photocured product can be more effectively enhanced by combining the monomer C with the monomer B.

[0021] Monomer C is not particularly limited as long as it is a polyfunctional ethylenically unsaturated monomer having an isocyanurate ring structure, and examples thereof include polyfunctional (meth)acrylates having an isocyanurate ring structure, and allyl compounds having an isocyanurate ring structure. These monomers may be used alone or in combination of two or more. Examples of polyfunctional (meth)acrylates having an isocyanurate ring structure include isocyanuric acid ethylene oxide modified di- or triacrylate, ethoxylated isocyanuric acid triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, and bis(2-hydroxyethyl)isocyanurate diacrylate. Examples of allyl compounds having an isocyanurate ring structure include triallyl isocyanurate and diallyl isocyanurate.

[0022] Among these polyfunctional monomers, from the viewpoint of dimensional stability, polyfunctional (meth)acrylates having an isocyanurate ring structure are preferred, tri(meth)acrylates having an isocyanurate ring structure are more preferred, and tris(2-hydroxyethyl)isocyanurate triacrylate is particularly preferred.

[0023] The linear expansion coefficient of the homopolymer of the monomer C is preferably 200 ppm or less. The linear expansion coefficient is more preferably 150 ppm or less, even more preferably 120 ppm or less, particularly preferably 100 ppm or less, and particularly preferably 80 ppm or less. The lower limit is not particularly limited and may be 0 ppm, since the lower the linear expansion coefficient, the higher the thermal expansion suppression effect tends to be. When the linear expansion coefficient is equal to or less than the upper limit, the thermal expansion of the photocured product obtained from the stereolithography resin composition is easily suppressed, and the dimensional stability of the photocured product in a high temperature environment is easily improved. The linear expansion coefficient can be measured in a temperature range below the glass transition temperature, for example, from room temperature to the glass transition temperature of the homopolymer -30°C, using a homopolymer of the monomer C as a test piece, according to JIS K 7197. In detail, the linear expansion coefficient can be measured, for example, by the method described in the Examples. For example, the homopolymer of the monomer C can be measured by adding a photopolymerization initiator to the monomer C, and then exposing the monomer C to a metal halide lamp with an integrated light amount of 500 mJ / cm. 2 The resin is then cured by exposure to ultraviolet light.

[0024] The content of the monomer C is 5 to 80 parts by mass relative to 100 parts by mass of the stereolithography resin composition. If the content of the monomer C is less than the lower limit, it is difficult to impart sufficiently high dimensional stability to the obtained photocured product, and if it exceeds the upper limit, the viscosity of the stereolithography resin composition is likely to increase excessively. In addition, from the viewpoint of dimensional stability, the content of the monomer C is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and even more preferably 20 parts by mass or more relative to 100 parts by mass of the stereolithography resin composition. In addition, from the viewpoint of viscosity of the stereolithography resin composition, it is preferably 75 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less.

[0025] In one embodiment of the present invention, when the stereolithography resin composition is a model material composition used in a material jet stereolithography method, the content of the monomer C suitable for the material jet stereolithography method is 5 to 50 parts by mass relative to 100 parts by mass of the model material composition. If the content of the monomer C is less than the lower limit, it is difficult to impart sufficiently high dimensional stability to the obtained model material, and if it exceeds the upper limit, the viscosity of the model material composition is likely to increase excessively, making it difficult to apply to the material jet stereolithography method. In addition, from the viewpoint of dimensional stability, the content of the monomer C is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and even more preferably 20 parts by mass or more relative to 100 parts by mass of the model material composition. In addition, from the viewpoint of the viscosity of the model material composition, it is preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less.

[0026] In the stereolithography resin composition of the present invention, the ratio of the total mass of monomer B to the total mass of monomer C, monomer B:monomer C (mass ratio), is preferably 1:20 to 10:1, more preferably 1:10 to 5:1, even more preferably 1:5 to 2:1, and particularly preferably 1:1.2 to 1.2:1. When the mass ratio of monomer B to monomer C is within the above range, it is easy to impart excellent dimensional stability to the obtained photocured product. When the stereolithography resin composition contains monomer B and monomer C in approximately the same mass ratio, it is easier to suppress molecular vibration in the obtained photocured product, and it is easier to improve dimensional stability.

[0027] In one embodiment of the present invention, when the stereolithography resin composition is a model material composition used in material jet stereolithography, the ratio of the total mass of monomer B to the total mass of monomer C suitable for material jet stereolithography, monomer B:monomer C (mass ratio), is preferably 1:10 to 10:1, more preferably 1:5 to 5:1, even more preferably 1:2 to 2:1, and particularly preferably 1:1.2 to 1.2:1. When the mass ratio of monomer B to monomer C is within the above range, it is easy to impart excellent dimensional stability to the obtained model material. When the model material composition contains monomer B and monomer C in approximately the same mass ratio, it is easier to suppress molecular vibration in the obtained model material, and it is easier to improve dimensional stability.

[0028] [Monofunctional ethylenically unsaturated monomer (A) (monomer A)] From the viewpoint of easily adjusting the viscosity to an appropriate level depending on the stereolithography method to be used, the stereolithography resin composition of the present invention preferably contains a monofunctional ethylenically unsaturated monomer (A) (hereinafter also referred to as "monomer A") in addition to the monomer B and the monomer C. When the stereolithography resin composition of the present invention contains the monomer A, the viscosity is easily adjusted to a level suitable for the material jet stereolithography method. In the present invention, examples of the monofunctional ethylenically unsaturated monomer (A) include alkyl (meth)acrylates having a linear or branched alkyl group; (meth)acrylates having a ring structure such as an alicyclic structure, an aromatic ring structure, or a heterocyclic structure in the molecule; and monofunctional ethylenically unsaturated monomers containing a nitrogen atom such as (meth)acrylamide and N-vinyl lactams. These monomers may be used alone or in combination of two or more. In this specification, "(meth)acrylamide" refers to both or either of acrylamide and methacrylamide. In this specification, the term "aromatic ring structure" refers to an aromatic ring structure in which carbon atoms are bonded in a ring, and the term "heterocyclic structure" refers to a structure in which carbon atoms and one or more heteroatoms are bonded in a ring.

[0029] Examples of alkyl (meth)acrylates having a linear or branched alkyl group include alkyl (meth)acrylates having a linear or branched alkyl group, preferably having 4 to 30 carbon atoms, more preferably having 6 to 20 carbon atoms. Specific examples include methyl (meth)acrylate, ethyl (meth)acrylate, isobutyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, 2-ethylhexyl-diglycol (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, and t-butyl (meth)acrylate. , β-carboxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxy-diethylene glycol (meth)acrylate, methoxy-triethylene glycol (meth)acrylate, methoxy-polyethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, caprolactone (meth)acrylate, 2-(meth)acryloyloxyethyl-succinic acid, and the like.

[0030] Examples of the (meth)acrylate having an alicyclic structure include (meth)acrylates having an alicyclic structure preferably having 6 to 20 carbon atoms, more preferably having 8 to 15 carbon atoms. Specific examples include cyclohexyl (meth)acrylate, 4-t-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, and 3,3,5-trimethylcyclohexanol (meth)acrylate.

[0031] Examples of (meth)acrylates having an aromatic ring structure include (meth)acrylates having an aromatic ring structure preferably having 6 to 20 carbon atoms, more preferably having 8 to 15 carbon atoms. Specific examples include phenoxyethyl (meth)acrylate, phenoxy-polyethylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, nonylphenol ethylene oxide adduct (meth)acrylate, 2-(meth)acryloyloxyethyl-phthalic acid, neopentyl glycol-acrylic acid-benzoic acid ester, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, benzyl acrylate, phenylphenol acrylate, and fluorene acrylate.

[0032] Examples of the (meth)acrylate having a heterocyclic structure include (meth)acrylates having a heterocyclic structure preferably having 5 to 20 carbon atoms, more preferably having 7 to 15 carbon atoms. Specific examples include tetrahydrofurfuryl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, 4-(meth)acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, and 4-(meth)acryloyloxymethyl-2-cyclohexyl-1,3-dioxolane.

[0033] In addition, examples of the nitrogen atom-containing monofunctional ethylenically unsaturated monomer different from the above (meth)acrylates include (meth)acrylamides (e.g., N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, hydroxyethylacrylamide, hydroxypropylacrylamide, N,N-acryloylmorpholine, etc.), N-vinyllactams (e.g., N-vinylpyrrolidone, N-vinylcaprolactam, etc.), and N-vinylformamide.

[0034] Among these monofunctional monomers, the monomer A is preferably a monofunctional ethylenically unsaturated monomer having a ring structure in the molecule. When the monomer A is a monofunctional ethylenically unsaturated monomer having a ring structure in the molecule, a photocured product having high dimensional stability is easily obtained. This is presumably because, compared with the monomer A having no ring structure, it is easier to suppress the vibration of the molecules in the photocured product obtained from the stereolithography resin composition. In the stereolithography resin composition of the present invention, the content of the monofunctional ethylenically unsaturated monomer having a ring structure in the molecule is preferably 50% by mass or more, more preferably 80% by mass or more, based on the total mass of the monofunctional ethylenically unsaturated monomer (A), and all the monofunctional ethylenically unsaturated monomers (A) contained in the stereolithography resin composition may have a ring structure in the molecule.

[0035] From the viewpoint of heat resistance, the glass transition temperature Tg of the homopolymer of the monomer A is preferably 80° C. or higher, more preferably 100° C. or higher, and even more preferably 120° C. or higher. From the viewpoint of curing shrinkage when the stereolithography resin composition is cured, the glass transition temperature Tg of the monomer A is preferably 200° C. or lower, more preferably 180° C. or lower, and even more preferably 160° C. or lower. The glass transition temperature is measured by a differential scanning calorimeter (DSC) using a homopolymer of the monomer A as a test piece. In detail, it is measured by the method described in the examples, for example.

[0036] The content of the monomer A is less than 70 parts by mass relative to 100 parts by mass of the resin composition for stereolithography. When the content of the monomer A is equal to or less than the upper limit, the dimensional stability of the photocured product obtained is easily improved. The lower limit of the content of the monomer A is not particularly limited, but from the viewpoint of imparting a viscosity suitable for stereolithography to the resin composition for stereolithography, it is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 19 parts by mass or more relative to 100 parts by mass of the resin composition for stereolithography. From the viewpoint of dimensional stability, it is preferably 65 parts by mass or less, more preferably 59 parts by mass or less, even more preferably 55 parts by mass or less, even more preferably 53 parts by mass or less, and particularly preferably 48 parts by mass or less.

[0037] In one embodiment of the present invention, when the stereolithography resin composition is a model material composition used in a material jet stereolithography method, the model material composition contains a monomer A in addition to the monomer B and the monomer C. The content of the monomer A suitable for the material jet stereolithography method is 19 to 59 parts by mass relative to 100 parts by mass of the model material composition. If the content of the monomer A is less than the lower limit, it is difficult to adjust the viscosity of the model material composition to an appropriate range, and if it exceeds the upper limit, it is difficult to impart sufficiently high dimensional stability to the obtained model material. In addition, the content of the monomer A is preferably 25 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 35 parts by mass or more, relative to 100 parts by mass of the model material composition, from the viewpoint of imparting a viscosity suitable for the material jet stereolithography method to the model material composition. In addition, from the viewpoint of dimensional stability, it is preferably 55 parts by mass or less, more preferably 53 parts by mass or less, and even more preferably 48 parts by mass or less.

[0038] When the stereolithography resin composition of the present invention contains monomer A, the ratio of the total mass of monomer A to the total mass of monomer B in the stereolithography resin composition, monomer A:monomer B (mass ratio), is preferably 10:1 to 1:8, more preferably 5:1 to 1:4, and even more preferably 2:1 to 1:2. When the mass ratio of monomer A to monomer B is within the above range, it is easy to achieve both an appropriate viscosity of the stereolithography resin composition and high dimensional stability of the obtained photocured product in a high-temperature environment.

[0039] In one embodiment of the present invention, when the stereolithography resin composition is a model material composition used in material jet stereolithography, the ratio of the total mass of the monomer A to the total mass of the monomer B suitable for material jet stereolithography, that is, monomer A:monomer B (mass ratio), is preferably 10:1 to 1:3, more preferably 5:1 to 1:2, and even more preferably 2:1 to 1:1. When the mass ratio of monomer A to monomer B is within the above range, it is easy to achieve both an appropriate viscosity of the model material composition and high dimensional stability of the obtained model material under high temperature environments.

[0040] When the stereolithography resin composition of the present invention contains monomer A, the ratio of the total mass of monomer A to the total mass of monomer C in the stereolithography resin composition, monomer A:monomer C (mass ratio), is preferably 10:1 to 1:10, more preferably 5:1 to 1:5, and even more preferably 2:1 to 1:2. When the mass ratio of monomer A to monomer C is within the above range, it is easy to achieve both an appropriate viscosity of the stereolithography resin composition and high dimensional stability of the obtained photocured product in a high-temperature environment.

[0041] In one embodiment of the present invention, when the stereolithography resin composition is a model material composition used in material jet stereolithography, the ratio of the total mass of monomer A to the total mass of monomer C suitable for material jet stereolithography, monomer A:monomer C (mass ratio), is preferably 10:1 to 1:3, more preferably 5:1 to 1:2, and even more preferably 2:1 to 1:1. When the mass ratio of monomer A to monomer C is within the above range, it is easy to achieve both an appropriate viscosity of the model material composition and high dimensional stability of the obtained model material under high temperature environments.

[0042] The stereolithography resin composition of the present invention contains both monomer B and monomer C, which suppresses the thermal expansion of the photocured product obtained, and is likely to sufficiently improve the dimensional stability in a high-temperature environment. When the stereolithography resin composition of the present invention contains monomer A, the ratio of the total mass of monomer B and monomer C to the total mass of monomer A in the stereolithography resin composition (monomer B + monomer C) / monomer A (mass ratio) is preferably 0.5 to 10, more preferably 0.5 to 5, even more preferably 0.8 to 4, even more preferably 0.8 to 3, particularly preferably 1 to 2, and particularly preferably 1 to 1.5. When the ratio of the total mass of monomer B and monomer C to the total mass of monomer A is within the above range, it is easy to achieve both an appropriate viscosity of the stereolithography resin composition and high dimensional stability of the photocured product obtained in a high-temperature environment. In addition, in the stereolithography resin composition of the present invention, the total content of the monomer B and the monomer C is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on the total amount of all polymerizable compounds in the stereolithography resin composition, from the viewpoint of dimensional stability. In addition, from the viewpoint of the viscosity of the stereolithography resin composition, it is preferably 95% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and particularly preferably 60% by mass or less. In this specification, the term "polymerizable compound" refers to a compound having a polymerizable group, such as a polymerizable monomer or a polymerizable oligomer. In the stereolithography resin composition of the present invention, the total content of the monomers B and C is preferably more than 30 parts by mass, more preferably 35 parts by mass or more, and even more preferably 40 parts by mass or more, based on 100 parts by mass of the stereolithography resin composition, from the viewpoint of dimensional stability. Also, from the viewpoint of the viscosity of the stereolithography resin composition, it is preferably 95 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less.

[0043] [Other polymerizable compounds] The stereolithography resin composition of the present invention may contain other polymerizable compounds other than the monomer B and the monomer C, and the monomer A that may be included in some cases. Examples of other polymerizable compounds include polyfunctional polymerizable monomers that do not have a ring structure, and polymerizable oligomers. In this specification, the term "polymerizable oligomer" refers to a photocurable component that has the property of being cured by energy rays, and has a weight average molecular weight Mw of 1,000 to 10,000. The weight average molecular weight Mw is measured using GPC (Gel Permeation Chromatography) in terms of standard polystyrene.

[0044] Examples of the polyfunctional polymerizable monomer having no ring structure include polyfunctional ethylenically unsaturated monomers having no ring structure in the molecule, such as epoxy poly(meth)acrylate, polyester poly(meth)acrylate, poly(meth)acrylate having a urethane group, etc. These polyfunctional polymerizable monomers may be used alone or in combination of two or more kinds.

[0045] Examples of the polymerizable oligomer include epoxy (meth)acrylate oligomer, polyester (meth)acrylate oligomer, and urethane (meth)acrylate oligomer. These polymerizable oligomers may be used alone or in combination of two or more. By including the polymerizable oligomer, flexibility can be easily imparted to the photocured product obtained from the stereolithography resin composition. A preferred polymerizable oligomer is a polymerizable oligomer having a urethane group, and more preferably a urethane (meth)acrylate oligomer.

[0046] When the stereolithography resin composition contains other polymerizable compounds, the content thereof is not limited as long as it does not impair the effects of the present invention, and is, for example, preferably 0.1 to 30 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of the stereolithography resin composition.

[0047] The total amount of the polymerizable compounds contained in the stereolithography resin composition is preferably 10 to 99 parts by mass, more preferably 29 to 99 parts by mass, even more preferably 50 to 98 parts by mass, and particularly preferably 80 to 95 parts by mass, per 100 parts by mass of the stereolithography resin composition.

[0048] [Other additives] The stereolithography resin composition of the present invention may contain other additives as necessary within the range that does not impair the effects of the present invention. Examples of other additives include photopolymerization initiators, surface conditioners, colorants, storage stabilizers, antioxidants, UV absorbers, light stabilizers, polymerization inhibitors, chain transfer agents, fillers, diluents, thickeners, etc.

[0049] (Photopolymerization initiator (D)) The photopolymerization initiator is not particularly limited as long as it is a compound that promotes a radical reaction by irradiation with ultraviolet light, near ultraviolet light, or light with a wavelength in the visible light region. Examples of the photopolymerization initiator include benzoin compounds having 14 to 18 carbon atoms [e.g., benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, etc.], acetophenone compounds having 8 to 18 carbon atoms [e.g., acetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one, diethoxyacetophenone, 1,1-dichloro ... anthraquinone compounds having 14 to 19 carbon atoms (e.g., 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-chloroanthraquinone, 2-amylanthraquinone, etc.), thioxanthone compounds having 13 to 17 carbon atoms (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, etc.), ketal compounds having 16 to 17 carbon atoms (e.g., acetophenone dimethyl ketal, benzyl dimethyl ketal, benzophenone compounds having 13 to 21 carbon atoms (e.g., benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 4,4'-bismethylaminobenzophenone, etc.), acylphosphine oxide compounds having 22 to 28 carbon atoms (e.g., 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, phenoxides), α-aminoalkylphenone compounds (e.g., 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1, 2-methyl-1-[4-(methoxythio)phenyl]-2-morpholinopropan-2-one, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, etc.), and mixtures of these compounds.These may be used alone or in combination of two or more. Among these, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is preferred because the photocured product and photomodeled product obtained by photocuring the photopolymerization resin composition are less likely to yellow, and the photocured product and photomodeled product obtained have high light resistance and are less likely to yellow over time. In addition, examples of available acylphosphine oxide compounds include DAROCURE TPO manufactured by BASF.

[0050] When the stereolithography resin composition contains a photopolymerization initiator, the content is preferably 1 to 15 parts by mass, more preferably 3 parts by mass or more, and more preferably 12 parts by mass or less, based on 100 parts by mass of the stereolithography resin composition. When the content of the photopolymerization initiator is equal to or more than the lower limit, the amount of unreacted polymerization components is sufficiently reduced, and the curability of the photocured product is easily enhanced. On the other hand, when the content of the photopolymerization initiator is equal to or less than the upper limit, the amount of the photopolymerization initiator remaining unreacted in the photocured product is easily reduced, and the yellowing of the photocured product caused by the remaining unreacted photopolymerization initiator is easily suppressed.

[0051] (Surface conditioner (E)) The surface conditioner is a component that adjusts the surface tension of the stereolithography resin composition to an appropriate range, and the type is not particularly limited. By adjusting the surface tension of the stereolithography resin composition to an appropriate range, when the stereolithography resin composition is used in a material jet stereolithography method, the dischargeability can be stabilized and the interfacial mixing between the model material composition and the support material composition can be suppressed. As a result, a stereolithography product with good dimensional accuracy can be easily obtained.

[0052] Examples of the surface conditioner include silicone compounds. Examples of the silicone compounds include silicone compounds having a polydimethylsiloxane structure. Specific examples of the silicone compounds include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, and polyaralkyl-modified polydimethylsiloxane. These include, by trade name, BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-315, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-344, BYK-370, BYK-375, BYK-377, BYK-UV3500, BYK-UV3510, BYK-UV3570 (all manufactured by BYK-Chemie); TEGO-Rad2100, TE GO-Rad2200N, TEGO-Rad2250, TEGO-Rad2300, TEGO-Rad2500, TEGO-Rad2600, TEGO-Rad2700 (all manufactured by Evonik Japan Co., Ltd.); Granol 100, Granol 115, Granol 400, Granol 410, Granol 435, Granol 440, Granol 450, B-1484, Polyflow ATF-2, KL-600, UCR-L72, UCR-L93 (manufactured by Kyoeisha Chemical Co., Ltd.), etc. may also be used. Surface conditioners other than silicone-based compounds (e.g., fluorine-based surface conditioners, etc.) may also be used. These may be used alone or in combination of two or more.

[0053] When the stereolithography resin composition contains a surface conditioner, the content thereof is preferably 0.005 to 3 parts by mass, more preferably 0.01 parts by mass or more, and more preferably 1.5 parts by mass or less, relative to 100 parts by mass of the stereolithography resin composition. When the content of the surface conditioner is within the above range, it is easy to adjust the surface tension of the stereolithography resin composition to an appropriate range.

[0054] (Storage stabilizer (F)) The storage stabilizer is a component that can enhance the storage stability of the stereolithography resin composition. In addition, when the stereolithography resin composition is a model material composition used in a material jet stereolithography method, the storage stabilizer can prevent head clogging caused by polymerization of the polymerizable compound by thermal energy.

[0055] Examples of the storage stabilizer include hindered amine compounds (HALS), phenolic antioxidants, and phosphorus antioxidants.Specific examples include hydroquinone, methoquinone, benzoquinone, p-methoxyphenol, hydroquinone monomethyl ether, hydroquinone monobutyl ether, TEMPO, 4-hydroxy-TEMPO, TEMPOL, H-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl), Cupferron Al; IRGASTAB UV-10, IRGASTAB UV-22, and FIRSTCURE ST-1 manufactured by ALBEMARLE; t-butylcatechol, pyrogallol; and TINUVIN 111 FDL, TINUVIN 144, TINUVIN 292, TINUVIN XP40, TINUVIN XP60, and TINUVIN 400 manufactured by BASF.These may be used alone or in combination of two or more kinds.

[0056] When the resin composition for photopolymerization contains a storage stabilizer, from the viewpoint of easily obtaining the above-mentioned effect, the content thereof is preferably 0.05 to 3 parts by mass, more preferably 0.08 parts by mass or more, and more preferably 2 parts by mass or less, per 100 parts by mass of the resin composition for photopolymerization.

[0057] [Coloring Agent] The stereolithography resin composition of the present invention may further contain a colorant. The colorant is not particularly limited, but since the stereolithography resin composition of the present invention is non-aqueous, a pigment that is easily dispersed uniformly in a non-aqueous medium or a dye that is easily dissolved therein is preferred.

[0058] The pigment may be either inorganic or organic. Examples of inorganic pigments include titanium oxide, zinc oxide, lithopone, iron oxide, aluminum oxide, silicon dioxide, kaolinite, montmorillonite, talc, barium sulfate, calcium carbonate, silica, alumina, cadmium red, red iron oxide, molybdenum red, chrome vermilion, molybdate orange, yellow lead, chrome yellow, cadmium yellow, yellow iron oxide, titanium yellow, chrome oxide, pyridian, cobalt green, titanium cobalt green, cobalt chrome green, ultramarine blue, Prussian blue, cobalt blue, cerulean blue, manganese violet, cobalt violet, and mica. Examples of organic pigments include azo, azomethine, polyazo, phthalocyanine, quinacridone, anthraquinone, indigo, thioindigo, quinophthalone, benzimidazolone, and isoindoline organic pigments. Carbon black made of acidic, neutral or basic carbon may also be used. Furthermore, hollow particles of crosslinked acrylic resin may also be used as an organic pigment.

[0059] In the resin composition for stereolithography of the present invention, pigments of the three primary colors, namely black and cyan, magenta, and yellow, are usually used, but pigments of other hues, metallic luster pigments such as gold and silver, and colorless or light-colored extender pigments can also be used depending on the purpose.

[0060] The above colorants may be used alone or in combination of two or more. In the present invention, two or more organic pigments or solid solutions of organic pigments may be used in combination. Different colorants may be used for each droplet and liquid to be ejected, or the same colorant may be used.

[0061] The colorant can be dispersed using a dispersing device such as a bead mill, a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, etc., or a mixer such as a line mixer, etc. After dispersing the colorant, classification treatment may be performed using a centrifuge, a filter, a cross flow, etc., for the purpose of removing coarse particles of the colorant.

[0062] When dispersing the colorant, a dispersant may be added. There are no particular limitations on the type of dispersant, but it is preferable to use a known polymer dispersant.

[0063] The content of the dispersant is appropriately selected depending on the purpose of use, but may be, for example, 0.01 to 5 parts by mass relative to 100 parts by mass of the stereolithography resin composition.

[0064] When the colorant is added, a synergist suitable for each colorant may be used as a dispersing aid, if necessary.

[0065] The content of the colorant is appropriately selected depending on the color and purpose of use, but from the viewpoints of image density and storage stability, it is preferably 0.05 to 30 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the resin composition for stereolithography.

[0066] The method for producing the stereolithography resin composition of the present invention is not particularly limited. For example, the stereolithography resin composition can be produced by uniformly mixing the components constituting the stereolithography resin composition using a mixer or the like.

[0067] [Properties of the Stereolithography Resin Composition and its Photocured Product] The viscosity of the stereolithography resin composition of the present invention may be any viscosity suitable for the stereolithography method employed, and may be, for example, 10 to 2500 mPa·s, and preferably 20 to 1500 mPa·s at 25°C. In one embodiment of the present invention, when the stereolithography resin composition is a model material composition used in a material jet stereolithography method, the viscosity of the model material composition of the present invention is preferably 20 mPa·s or more, more preferably 30 mPa·s or more, and even more preferably 35 mPa·s or more, and is preferably 100 mPa·s or less, more preferably 90 mPa·s or less, and even more preferably 85 mPa·s or less at 25° C., from the viewpoint of improving the dischargeability from a material jet nozzle. The viscosity can be measured using an R100 type viscometer in accordance with JIS Z 8803. The viscosity of the stereolithography resin composition can be controlled by adjusting the type and mixing ratio of the ethylenically unsaturated monomer, the type and amount of the dilution solvent and thickener, and the like.

[0068] The linear expansion coefficient of the photocured product of the present invention obtained by photocuring the stereolithography resin composition of the present invention is preferably 150 ppm or less. The linear expansion coefficient is more preferably 130 ppm or less, even more preferably 120 pm or less, and particularly preferably less than 100 ppm. The lower the linear expansion coefficient, the higher the thermal expansion suppression effect tends to be, so the lower limit is not particularly limited and may be 0 ppm. When the linear expansion coefficient is equal to or less than the upper limit, the thermal expansion of the photocured product can be easily suppressed even in a high-temperature environment, for example, above 100°C, and high dimensional stability can be ensured. The linear expansion coefficient is measured, for example, in a temperature range below the glass transition temperature, for example, in the range from room temperature to the glass transition temperature of the homopolymer minus 30°C, according to JIS K 7197. In detail, for example, when the total amount of light irradiated to the stereolithography resin composition is 500 mJ / cm 2 The total amount of irradiation light is measured by the method described in the Examples, using a photocured product cured by irradiation with ultraviolet light so that the total amount of irradiation light is measured by, for example, a UV METER UVPF-36 (manufactured by Eye Graphics Co., Ltd.).

[0069] The photocured product of the present invention has a low linear expansion coefficient and small dimensional change in a high-temperature environment, so it is suitable for applications in high-temperature environments. Examples of such applications include housings for electronic devices and components constituting electronic devices. In particular, the photocured product of the present invention is suitable for printed circuit board components for electronic devices (e.g., insulating boards for printed wiring). In general, when a printed circuit board component is manufactured, a liquid metal is linearly arranged on the printed circuit board component and baked to form metal wiring. Such a process is usually carried out in a high-temperature environment exceeding 100°C. If the printed circuit board component is made of a photocured product that does not have sufficient heat resistance, it is likely to thermally expand in such a high-temperature environment, and the metal wire arranged on the component may be cracked by applying tensile stress to the metal wire. The printed circuit board component formed using the photocured product of the present invention is unlikely to thermally expand even in such a high-temperature environment and has high dimensional stability, so that defects such as the above-mentioned cracking of the metal wire are unlikely to occur.

[0070] The printed circuit board member can be manufactured by forming the desired shape of the printed circuit board member by a stereolithography method using the stereolithography resin composition of the present invention and photocuring it. For example, the model material composition of the present invention can be manufactured by forming a stereolithography (or three-dimensional object) having the shape of the desired printed circuit board member by a material jet stereolithography method. The stereolithography may be manufactured, for example, by the method described below. A printed circuit board produced by wiring metal wires or electronic components directly or indirectly by a known method such as soldering on a printed circuit board member formed using the resin composition for stereolithography of the present invention is less susceptible to thermal expansion even in high-temperature environments and has high dimensional stability, and therefore is less susceptible to defects such as cracking of metal wires than printed circuit boards produced using conventional resin compositions for stereolithography.

[0071] <Material Jet Photopolymerization Composition Set> In order to model complex or intricate shapes with high accuracy, the model material composition of the present invention is preferably used in combination with a supporting material for supporting the model material during three-dimensional modeling. Therefore, the present invention also relates to a material jet stereolithography composition set comprising the model material composition of the present invention and a supporting material composition for modeling a supporting material by a material jet stereolithography method, which is used together with the model material composition.

[0072] [Support material composition] The support material composition is a composition used in the material jet stereolithography method, and forms a support material by photocuring. After the model material is produced, the support material can be removed from the model material by physically peeling it off from the model material, or by dissolving the support material in an organic solvent or water. The model material composition of the present invention can be used in combination with various compositions conventionally known as support material compositions, but the support material composition constituting the material jet stereolithography composition set of the present invention is preferably water-soluble, since the model material is not damaged when the support material is removed, it is environmentally friendly, and the support material can be easily and cleanly removed down to the finest details.

[0073] (Polyalkylene glycol containing an oxybutylene group) Examples of the water-soluble support material composition include those containing polyalkylene glycols containing oxybutylene groups. Although polyalkylene glycols containing oxybutylene groups are water-soluble, they do not have hydrophilicity that reduces the support strength of the support material when the support material is formed. However, since polyalkylene glycols containing oxybutylene groups are water-soluble, they have excellent water removability when the support material is formed.

[0074] Polyalkylene glycol containing an oxybutylene group is a water-soluble resin that imparts a suitable degree of hydrophilicity to the support material, and by adding this, it is possible to obtain a support material that combines water removal properties and support power.

[0075] As long as the polyalkylene glycol containing an oxybutylene group contains an oxybutylene group, the structure of the alkylene portion is not particularly limited, and it may be, for example, a polybutylene glycol alone having only an oxybutylene group (oxytetramethylene group), or it may be a polybutylene polyoxyalkylene glycol (for example, polybutylene polyethylene glycol) having both an oxybutylene group and another oxyalkylene group.

[0076] Polybutylene glycol is represented by the following chemical formula (1), and polybutylene polyethylene glycol is represented by the following chemical formula (2).

[0077] HO(CH2CH2CH2CH2O) n H (1) HO(CH2CH2CH2CH2O) m (C2H4O) n H (2)

[0078] In chemical formula (2), m is preferably an integer of 5 to 300, and n is preferably an integer of 2 to 150. More preferably, m is 6 to 200, and n is 3 to 100. In addition, the oxybutylene group in chemical formula (1) and chemical formula (2) may be linear or branched.

[0079] The content of the polyalkylene glycol containing an oxybutylene group is preferably 15 to 75 parts by mass, more preferably 17 to 72 parts by mass, and even more preferably 20 to 70 parts by mass, based on 100 parts by mass of the support material composition. When the content is equal to or greater than the lower limit, the hydrophilicity of the support material is improved, and the water removability of the support material is easily improved. When the content is equal to or less than the upper limit, the softening of the support material is suppressed, and the support material is easily able to maintain its self-supporting property, and therefore the support power of the support material is easily improved.

[0080] The weight average molecular weight of the polyalkylene glycol containing an oxybutylene group is preferably 300 to 3,000, more preferably 800 to 2,000. When the weight average molecular weight of the polyalkylene glycol containing an oxybutylene group is equal to or greater than the lower limit, bleeding of the support material when the support material composition is cured is easily suppressed. Note that bleeding is a phenomenon in which liquid components seep out from inside the cured support material to the surface of the support material. In addition, when the weight average molecular weight of the polyalkylene glycol containing an oxybutylene group is equal to or less than the upper limit, the ejection stability of the support material composition is easily improved.

[0081] The polyalkylene glycol containing oxybutylene group may be used alone or in combination of two or more.When two or more kinds of polyalkylene glycol containing oxybutylene group are used, the content of the polyalkylene glycol containing oxybutylene group having weight average molecular weight within the above range is preferably 80 mass% or more, more preferably 90 mass% or more, even more preferably 95 mass% or more, and particularly preferably 100 mass% of the total amount of the polyalkylene glycol containing oxybutylene group.

[0082] (Water-soluble monofunctional ethylenically unsaturated monomer) The support material composition included in the material jet stereolithography composition set of the present invention preferably contains a water-soluble monofunctional ethylenically unsaturated monomer in addition to the polyalkylene glycol containing an oxybutylene group. The water-soluble monofunctional ethylenically unsaturated monomer is polymerized to become a constituent of the support material and exerts a supporting ability. Although the water-soluble monofunctional ethylenically unsaturated monomer is water-soluble, it tends to impart hardness to the support material and improve the supporting ability.

[0083] Examples of the water-soluble monofunctional ethylenically unsaturated monomer include hydroxyl group-containing (meth)acrylates having a carbon number (C) of 5 to 15 [hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.]; alkylene oxide adduct-containing (meth)acrylates having a number average molecular weight (Mn) of 200 to 1000 [polyethylene glycol mono(meth)acrylate, monoalkoxy (C1 to 4) polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, monoalkoxy (C1 to 4) polypropylene glycol mono(meth)acrylate, etc.]; acrylate and mono(meth)acrylate of PEG-PPG block polymer, etc.; C3-15 (meth)acrylamide derivatives [(meth)acrylamide, N-methyl(meth)acrylamide, N-(ethylmeth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide, N,N'-dimethyl(meth)acrylamide, N,N'-diethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-hydroxypropyl(meth)acrylamide, and N-hydroxybutyl(meth)acrylamide, etc.], and (meth)acryloylmorpholine, etc. These water-soluble monofunctional ethylenically unsaturated monomers may be used alone or in combination of two or more.

[0084] The content of the water-soluble monofunctional ethylenically unsaturated monomer is preferably 15 to 80 parts by mass, more preferably 22 to 76 parts by mass, and even more preferably 25 to 73 parts by mass, relative to 100 parts by mass of the support material composition. When the content is equal to or more than the lower limit, the support ability of the support material is easily improved, and when the content is equal to or less than the upper limit, the water removability of the support material is easily improved.

[0085] (Photopolymerization initiator) The support material composition included in the material jet stereolithography composition set of the present invention may further contain a photopolymerization initiator.

[0086] The photopolymerization initiator contained in the supporting material composition is not particularly limited, and examples thereof include the same photopolymerization initiators as those in the model material composition described above, and preferred photopolymerization initiators are also the same as those in the model material composition.

[0087] The content of the photopolymerization initiator is preferably 1 to 20 parts by mass relative to 100 parts by mass of the support material composition. When the content of the photopolymerization initiator is within the above range, unreacted polymerization components can be sufficiently reduced, making it easy to sufficiently increase the curability of the support material.

[0088] (Chain transfer agent) The supporting material composition included in the material jet stereolithography composition set of the present invention preferably further contains a chain transfer agent. The chain transfer agent is not particularly limited as long as it is a compound that functions as a chain transfer agent for radical reaction. By using the chain transfer agent, the molecular weight of the cured product is reduced when the composition is irradiated with light to be photocured. The low-molecular-weight cured supporting material is likely to retain its solubility in water even when mixed with the modeling material composition. Therefore, the low-molecular-weight cured supporting material is less likely to remain on the surface of the photocured modeling material during water removal treatment.

[0089] Preferred specific examples of the chain transfer agent include thiol compounds such as 2-mercaptobenzothiazole and γ-mercaptoxypropyltrimethoxysilane, and 2,4-diphenyl-4-methyl-pentene.

[0090] The content of the chain transfer agent is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 4 parts by mass, and even more preferably 0.3 to 3 parts by mass, based on 100 parts by mass of the supporting material composition. When the content is equal to or greater than the lower limit, the decrease in solubility in water is easily suppressed even when the modeling material composition is mixed. When the content is equal to or less than the upper limit, the supporting material is easily cured, and the supporting power is easily improved.

[0091] (Water-soluble organic solvent) The support material composition included in the material jet stereolithography composition set of the present invention preferably further contains a water-soluble organic solvent, which has the effect of adjusting the viscosity of the support material composition so that it is suitable for ejection by the material jet stereolithography method.

[0092] Examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 1,5-pentanediol, 2,4-pentanediol, and 2,5-pentanediol. pentanediol, 1,2-hexanediol, 3,5-dimethyl-3-hexyne-2,5-diol, 2,5-hexanediol, hexylene glycol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,5-dimethyl-2,5-hexanediol, sulfolane, 1,4-cyclohexanedimethanol, 2,2-thiodiethanol, 3-pyridylcarbinol, propylene glycol monomethyl ether, dipropylene glycol methyl ether, trimethylol Examples of the propylene glycol methyl ether include propylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol t-butyl ether, dipropylene glycol t-butyl ether, propylene glycol phenyl ether, ethylene glycol methyl ether, diethylene glycol methyl ether, triethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol ethyl ether, triethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol n-butyl ether, diethylene glycol n-butyl ether, triethylene glycol n-butyl ether, ethylene glycol n-hexyl ether, diethylene glycol n-hexyl ether, and ethylene glycol phenyl ether. These may be used alone or in combination of two or more.

[0093] The content of the water-soluble organic solvent is preferably 30 parts by mass or less and preferably 5 parts by mass or more relative to 100 parts by mass of the support material composition. When the content of the water-soluble organic solvent is within the above range, the removability of the support material by water or a water-soluble solvent is easily improved without decreasing the support power of the support material.

[0094] In addition to the above components, the support material composition may further contain additives such as a surface conditioner, a storage stabilizer, etc. Examples of the surface conditioner and the storage stabilizer include compounds similar to the surface conditioner and storage stabilizer that can be contained in the model material composition.

[0095] When the supporting material composition contains a surface conditioner, the content thereof is preferably 0.005 to 3.0 parts by mass relative to 100 parts by mass of the supporting material composition. When the content is equal to or more than the lower limit, the surface tension of the supporting material composition is easily adjusted to an appropriate range. When the content is equal to or less than the upper limit, the generation of undissolved matter in the supporting material composition is suppressed, and foaming is easily prevented.

[0096] When the support material composition contains a storage stabilizer, the content thereof is preferably 0.005 to 1 part by mass, and more preferably 0.05 to 0.5 part by mass, relative to 100 parts by mass of the support material composition.

[0097] From the viewpoint of improving the dischargeability from the material jet nozzle, the viscosity of the support material composition in the present invention is preferably 1 to 500 mPa·s, and more preferably 20 to 400 mPa·s at 25° C. The viscosity can be measured in accordance with JIS Z 8 803 using an R100 type viscometer.

[0098] In the present invention, the method for producing the support material composition is not particularly limited, and the support material composition can be produced, for example, by uniformly mixing the components constituting the support material composition using a mixer or stirrer.

[0099] <Method of manufacturing optically modeled objects> A stereolithography (or three-dimensional object) can be formed from the stereolithography resin composition of the present invention, the model material composition of the present invention, or the material jet stereolithography composition set of the present invention by a stereolithography method, for example, a material jet stereolithography method. The method for producing a stereolithography by the material jet stereolithography method will be described in detail below.

[0100] The method for producing a photopolymerized object from the model material composition or photopolymerization composition set of the present invention is not particularly limited, and examples include a method including a step of photocuring the model material composition to obtain a model material and a step of photocuring the support material composition to obtain a supporting material, and a step of removing the supporting material from the model material.

[0101] In the above-mentioned manufacturing method, for example, data on a model material composition that is layered by a material jet method to form a three-dimensional object, and data on a supporting material composition that supports the three-dimensional object in the process of being produced are prepared based on 3D CAD data of the object to be produced, and slice data for discharging each composition with a material jet type 3D printer is further prepared. After each composition of the model material composition and the supporting material composition is discharged based on the prepared slice data, a photocuring process is repeated for each layer to produce a photo-cured object consisting of a photocured product of the model material composition (model material) and a photocured product of the supporting material composition (supporting material).

[0102] Examples of light for curing the model material composition and the support material composition include active energy rays such as far infrared rays, infrared rays, visible light, near ultraviolet rays, ultraviolet rays, electron beams, α rays, γ rays, and X-rays. Among these, near ultraviolet rays or ultraviolet rays are preferred from the viewpoint of ease and efficiency of the curing operation.

[0103] Examples of light sources include conventionally known high-pressure mercury lamps, metal halide lamps, UV-LEDs, etc. Among these, LED types are preferred from the viewpoints of downsizing the equipment and low power consumption. The amount of light is 200 to 500 mJ / cm from the viewpoints of hardness and dimensional accuracy of the molded product. 2 When using a UV-LED as the light source, it is preferable to use one with a central wavelength of 385 to 415 nm, since the light can easily reach deep layers and improve the hardness and dimensional accuracy of the molded object.

[0104] The thickness of each layer constituting the stereolithographic object is preferably thin from the viewpoint of modeling accuracy, but is preferably 5 to 30 μm in terms of the balance with modeling speed.

[0105] The obtained stereolithography is a combination of a model material and a supporting material. The supporting material can be removed from the stereolithography to obtain a stereolithography product, which is a model material. The supporting material is preferably removed by, for example, immersing the obtained model in a removal solvent that dissolves the supporting material, softening the supporting material, and then removing the supporting material from the surface of the model material with a brush or the like. The removal solvent for the supporting material may be water or a water-soluble solvent, such as a glycol-based solvent or an alcohol-based solvent. These may be used alone or in combination of two or more. EXAMPLES

[0106] The present invention will be described in detail below with reference to examples, but the scope of the present invention is not limited thereto. In the examples, "%" and "parts" are by mass % and parts by mass unless otherwise specified.

[0107] The abbreviations and details of the raw materials used in the examples and comparative examples are shown in Table 1 below.

[0108] [Table 1]

[0109] The glass transition temperature Tg of the monomer A in Table 1 was measured according to the following method. [Preparation of homopolymer of monomer A and measurement of glass transition temperature] Monomer A was mixed with 5% by mass of photopolymerization initiator (D) to prepare a composition for measuring the glass transition temperature (Tg) of monomer A. The composition for Tg measurement was dropped into an aluminum container for measurement, and then irradiated with an integrated light dose of 500 mJ / cm 2 from a metal halide lamp. 2 The composition for Tg measurement was irradiated with ultraviolet light to cure it, and a measurement sample was prepared. The glass transition temperature of the obtained measurement sample was measured by a differential scanning calorimeter (DSC) under the following conditions. (Measurement conditions) Measurement device: DSC8230 (Rigaku) Heating rate: 10℃ / min Scanning temperature: 30~200℃

[0110] The linear expansion coefficients of the monomers B and C in Table 1 were measured according to the following method. [Preparation of homopolymers of monomer B and monomer C and measurement of linear expansion coefficient] Each of the monomers B and C was mixed with 5% by mass of a photopolymerization initiator (D) to prepare compositions for measuring the linear expansion coefficient of monomer B and monomer C, respectively. A glass plate (trade name "GLASS PLATE", AS ONE Corporation, 200 mm x 200 mm x 5 mm thick) was partitioned into a rectangle of 10 mm x 5 mm by arranging 5 mm thick spacers on the four sides of the upper surface. Each composition for measuring the linear expansion coefficient was poured into the rectangle, and then another glass plate was placed on top of it. Next, a metal halide lamp was used to illuminate the glass plate, with an integrated light dose of 500 mJ / cm. 2 The cured product was then released from the glass plate to obtain homopolymers for measurement of monomer B and monomer C. The resulting homopolymers were used as test pieces to measure the linear expansion coefficient of the homopolymers of each monomer in the range of 25 to 200°C according to the thermomechanical analysis method (TMA method) specified in JIS K 7197.

[0111] (1) Preparation of resin composition for stereolithography The components constituting each stereolithography resin composition were mixed uniformly using a mixer / stirrer according to the compositions shown in Tables 2 and 3. After stirring, the resulting mixture was suction filtered using a glass filter (manufactured by Kiriyama Seisakusho) to prepare the stereolithography resin compositions of Examples 1 to 14 and Comparative Examples 1 to 4.

[0112] (2) Evaluation of physical properties of resin compositions for stereolithography The viscosity of each of the stereolithography resin compositions prepared in the above Examples and Comparative Examples was measured according to the method described below. The results are shown in Tables 2 and 3.

[0113] [Measurement of Viscosity] The viscosity of each stereolithography resin composition was measured using an R100 type viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25° C. and a cone rotation speed of 5 rpm. The results are shown in Tables 2 and 3.

[0114] (3) Evaluation of physical properties of cured resin compositions for stereolithography [Preparation of Photocured Product and Measurement of Linear Expansion Coefficient] A glass plate (trade name "GLASS PLATE", AS ONE Corporation, 200 mm x 200 mm x 5 mm thick) was partitioned into a 10 mm x 5 mm rectangle by placing 5 mm thick spacers on all four sides of the top surface. After each stereolithography resin composition was poured into the rectangle, another glass plate was placed on top of it. Next, a metal halide lamp was used as the irradiation means, with an integrated light quantity of 500 mJ / cm. 2 The photocured product was cured by irradiating it with ultraviolet light of 1000 nm. The cured product was then released from the glass plate to obtain a test piece. The linear expansion coefficient of each photocured product was measured in the range of 25 to 200°C using the test pieces obtained according to the thermomechanical analysis method (TMA method) specified in JIS K 7197, and evaluated according to the following criteria. The results are shown in Tables 2 and 3. (Evaluation criteria for linear expansion coefficient) ○: Less than 100 ppm △: 100ppm to 150ppm ×: Greater than 150 ppm

[0115] [Table 2]

[0116] [Table 3]

[0117] As is clear from the results of Tables 2 and 3, in Examples 1 to 14, which contain monomer B and monomer C in specific proportions, respectively, photocured products of the stereolithography composition with low linear expansion coefficients were obtained. Among them, in Examples 1 to 10, which contain 19 to 59 parts by mass of monomer A, 5 to 50 parts by mass of monomer B, and 5 to 50 parts by mass of monomer C relative to 100 parts by mass of the stereolithography resin composition, photocured products of the stereolithography resin composition with low linear expansion coefficients were obtained, and the viscosity of the stereolithography resin composition was less than 100 mPa·s, which was an appropriate viscosity applicable to the material jet stereolithography method. That is, the stereolithography resin compositions of Examples 1 to 10 were usable as model material compositions used in the material jet stereolithography method. On the other hand, in Comparative Examples 2 to 4, which do not contain monomer B and / or monomer C, the linear expansion coefficients of the obtained photocured products were high.

Claims

1. A model material composition for use in a material jet stereolithography method, comprising: 19 to 59 parts by weight of at least one monofunctional ethylenically unsaturated monomer (A); 5 to 50 parts by mass of at least one polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure; and At least one polyfunctional ethylenically unsaturated monomer (C) having an isocyanurate ring structure: 5 to 50 parts by mass Including, The monofunctional ethylenically unsaturated monomer (A) is a monofunctional ethylenically unsaturated monomer having a ring structure in the molecule, a total content of the at least one polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure and the polyfunctional ethylenically unsaturated monomer (C) having an isocyanurate ring structure is 35 parts by mass or more relative to 100 parts by mass of the model material composition.

2. 2. The model material composition according to claim 1, wherein the at least one polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure is a polyfunctional ethylenically unsaturated monomer having an alicyclic structure.

3. 3. The model material composition according to claim 1, wherein the monofunctional ethylenically unsaturated monomer (A) has a homopolymer having a glass transition temperature Tg of 80° C. or higher.

4. The model material composition according to any one of claims 1 to 3, wherein the polyfunctional ethylenically unsaturated monomer (B) having a ring structure other than an isocyanurate ring structure has a linear expansion coefficient of 200 ppm or less, measured at a temperature equal to or lower than the glass transition temperature of its homopolymer according to JIS K 7197.

5. The model material composition according to any one of claims 1 to 4, wherein the polyfunctional ethylenically unsaturated monomer (C) having an isocyanurate ring structure has a linear expansion coefficient of 200 ppm or less, measured at a temperature equal to or lower than the glass transition temperature of the homopolymer according to JIS K 7197.

6. The model material composition according to any one of claims 1 to 5, further comprising 1 to 15 parts by mass of a photopolymerization initiator (D) relative to 100 parts by mass of the model material composition.

7. The model material composition according to any one of claims 1 to 6, further comprising 0.005 to 3 parts by mass of a surface conditioner (E) relative to 100 parts by mass of the model material composition.

8. The model material composition according to any one of claims 1 to 7, further comprising 0.05 to 3 parts by mass of a storage stabilizer (F) relative to 100 parts by mass of the model material composition.

9. A model material which is a photocured product of the model material composition according to any one of claims 1 to 8.

10. 10. The model material according to claim 9, which has a linear expansion coefficient of 150 ppm or less, measured according to JIS K 7197 at or below the glass transition temperature.

11. A material jet stereolithography composition set comprising the model material composition according to any one of claims 1 to 8 and a supporting material composition used together with the model material composition.

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