Model material clear composition and stereolithography composition set

Abstract

To provide a model material clear composition for material jet stereolithography that can give a model material having increased storage stability and reduced yellowing of a polymerizable component and showing a clear and crystal-like color.SOLUTION: A model material clear composition comprises an ethylenically unsaturated monomer (A1) having at least one group selected from a group consisting of a dicyclopentenyl group and a dicyclopentanyl group, at least one photopolymerization initiator selected from a group consisting of an acylphosphine oxide-based photopolymerization initiator and an α-hydroxyacetophenone-based photopolymerization initiator, a hindered amine-based polymerization inhibitor, and a phenolic antioxidant, and contents (mass%) of the initiator, the polymerization inhibitor, and the antioxidant satisfy Formula (1): content of photopolymerization initiator≥content of polymerization inhibitor≥content of oxidation inhibitor, and Formula (2): 1≤√content of photopolymerization initiator / √[(content of polymerization inhibitor×10)2+(content of antioxidant×100)2]≤800.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a model material clear composition used for forming a model material by material jet stereolithography, and a material jet stereolithography composition set containing the model material clear composition. [Background technology]

[0002] Three-dimensional stereolithography, which produces a three-dimensional object by irradiating a photocurable resin composition with light such as ultraviolet light to continuously form cured layers having a predetermined shape, has been widely known. Among these, a material jet (inkjet) type stereolithography (hereinafter also referred to as "material jet stereolithography") has attracted widespread attention as a modeling method that enables the free production of three-dimensional objects using a 3D printer. This method involves ejecting a photocurable resin composition from a nozzle and then curing the resin composition by irradiating it with light such as ultraviolet light, thereby laminating cured layers having a predetermined shape to produce a three-dimensional object.

[0003] The clear modeling material composition used in material jet stereolithography is required to have specific properties for its intended use, such as minimal change in viscosity even after long-term storage, and the ability to provide a cured product with high transparency (transparency) and little yellowing with good dimensional accuracy.

[0004] Patent Document 1 describes a resin composition for modeling materials, which is used to model modeling materials by inkjet stereolithography and contains specific amounts of a water-insoluble monofunctional ethylenically unsaturated monomer (A), a difunctional or higher polyfunctional ethylenically unsaturated monomer (B), an oligomer (C), a photopolymerization initiator (D), and a surface modifier (E). This resin composition for modeling materials may contain an antioxidant as a storage stabilizer (F), which can prevent head clogging caused by polymerization of the polymerizable compound due to thermal energy.

[0005] The resin composition for modeling materials in Patent Document 1 has a small shrinkage rate when cured and can provide objects with good dimensional accuracy when formed by inkjet stereolithography. However, Patent Document 1 does not disclose any improvement in the storage stability of the ink or the transparency or color of the formed object.

[0006] Patent Document 2 describes a photocurable transparent ink composition for three-dimensional molding that contains a specific amount of a yellowing adjuster that absorbs light in the wavelength range of 560 nm to 650 nm. The transparent ink composition of Patent Document 2 utilizes the principle of complementary colors of light to prevent the cured product from turning yellow, as the yellowing adjuster reflects light of a color complementary to yellow light. The principle of complementary colors of light is based on the premise that the base material has a yellowish tint, and the yellowing adjuster adds a complementary color to cancel out the yellowness of the base material.

[0007] On the other hand, Patent Document 2 does not disclose any means for solving the problem of yellowing that occurs when polymerizable components such as monomers in the clear ink composition are photocured. Therefore, the clear ink composition of Patent Document 2 has a problem in that if the yellowness of the cured product becomes stronger due to a change in the polymerizable components, the color will become darker due to the yellowing adjuster.

[0008] Patent Document 3 describes a modeling material ink set containing a clear ink with a reduced content of nitrogen-containing ethylenically unsaturated monomers contained as polymerizable compounds. The modeling material ink set of Patent Document 3 can sufficiently increase the strength of a modeled object that is a photo-cured product of the color inks and clear ink, and can also prevent color change of the modeled object. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-31249 [Patent Document 2] Special Publication No. 2020-528018 [Patent Document 3] International Publication No. 2018 / 164012 Summary of the Invention [Problem to be solved by the invention]

[0010] In recent years, there has been a trend toward higher appearance characteristics for three-dimensional objects obtained by Material Jet Stereolithography, and there is a demand for model materials that are highly transparent and have a crystal-like color with even less yellowness. Here, "crystal-like" refers to a color similar to that of crystal glass, and crystal glass is high-quality, colorless, transparent glass.

[0011] The present invention solves the above-mentioned conventional problems, and its object is to provide a clear model material composition for material jet stereolithography, which has excellent storage stability, suppresses yellowing due to photocuring of the polymerizable component, and can produce a highly transparent model material that exhibits a crystalline color. [Means for solving the problem]

[0012] The present invention provides the following preferred embodiments. [1] A clear model material composition for use in a material jet stereolithography method, comprising an ethylenically unsaturated compound (A), a photopolymerization initiator, a polymerization inhibitor, and an antioxidant, The ethylenically unsaturated compound (A) is an ethylenically unsaturated monomer (A1) having at least one group selected from the group consisting of a dicyclopentenyl group and a dicyclopentanyl group; the photopolymerization initiator is at least one photopolymerization initiator selected from the group consisting of acylphosphine oxide-based photopolymerization initiators and α-hydroxyacetophenone-based photopolymerization initiators, the polymerization inhibitor is a hindered amine-based polymerization inhibitor, the antioxidant is a phenolic antioxidant, The contents (mass%) of the initiator, polymerization inhibitor, and antioxidant are expressed by the following formulas (1) and (2): Photopolymerization initiator content ≥ polymerization inhibitor content ≥ antioxidant content (1) 1≦ [ √Photopolymerization initiator content / √ { (polymerization inhibitor content x 10) 2 + (antioxidant content x 100) 2 }]×100 ≦800 (2) Meet the model material clear composition.

[0013] [2] The model material clear composition according to [1], wherein the ethylenically unsaturated monomer (A1) is contained in an amount of 30 mass % or more relative to the total mass of the ethylenically unsaturated compound (A).

[0014] [3] The ethylenically unsaturated compound (A) is The model material clear composition according to [1] or [2], further comprising an ethylenically unsaturated compound (A2) having an aliphatic cyclic structure in the molecule and having a urethane group.

[0015] [4] The model material clear composition according to [3], wherein the ethylenically unsaturated compound (A2) is contained in an amount of 10% by mass or more relative to the total mass of the ethylenically unsaturated compound (A).

[0016] [5] The ethylenically unsaturated compound (A) is The model material clear composition according to any one of [1] to [4], further comprising an ethylenically unsaturated monomer (A3) (excluding the ethylenically unsaturated monomer (A1) and the ethylenically unsaturated compound (A2)).

[0017] [6] The model material clear composition according to any one of [1] to [5], wherein the photopolymerization initiator is at least one photopolymerization initiator selected from the group consisting of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide, and 1-hydroxy-cyclohexyl-phenyl-ketone.

[0018] [7] The model material clear composition according to any one of [1] to [6], wherein the content of the photopolymerization initiator is 0.5 to 15% by mass.

[0019] [8] The model material clear composition according to any one of [1] to [7], wherein the content of the polymerization inhibitor is 0.01 to 5% by mass.

[0020] [9] The model material clear composition according to any one of [1] to [8], wherein the content of the antioxidant is 0.001 to 3 mass %.

[0021]

[10] The model material clear composition according to any one of [1] to [9], further comprising a surface conditioner.

[0022]

[11] The model material clear composition according to any one of [1] to

[10] , further comprising a colorant having an absorption wavelength in the range of 530 to 620 nm.

[0023]

[12] The model material clear composition according to any one of [1] to

[11] , wherein the viscosity of the model material clear composition stored for 30 days in an environment of 60°C has changed by less than 10% compared to the viscosity of the model material clear composition before storage.

[0024]

[13] At a thickness of 2 mm, the Lab color system L * The value is 90 or more, and a * The value is greater than or equal to -2 and less than 2, and b * The model material clear composition according to any one of [1] to

[12] , which provides a photocured product having a value of −10 or more and less than 4.

[0025]

[14] A photocured product obtained by photocuring the model material clear composition according to any one of [1] to

[13] .

[0026]

[15] A material jet stereolithography composition set comprising the model material clear composition according to any one of [1] to

[13] and a model material color composition used in material jet stereolithography.

[0027]

[16] A material jet stereolithography composition set comprising the model material clear composition according to any one of [1] to

[13] and a support material composition for forming a support material by material jet stereolithography.

[0028]

[17] The material jet stereolithography composition set according to

[16] , further comprising a model material color composition used in the material jet stereolithography method.

[0029]

[18] A stereolithography object obtained by photocuring the model material clear composition according to any one of [1] to

[13] or the material jet stereolithography composition set according to any one of

[15] to

[17] by material jet stereolithography. [Effects of the Invention]

[0030] According to the present invention, there is provided a clear model material composition for material jet stereolithography, which has excellent storage stability, suppresses yellowing due to photocuring of polymerizable components, and can produce a highly transparent model material that exhibits a crystalline color. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0032] [Ethylenically unsaturated compound (A)] The model material clear composition of the present invention contains an ethylenically unsaturated compound (A). The ethylenically unsaturated compound (A) is a polymerizable compound having at least one ethylenic double bond in the molecule, which has the property of being cured by energy rays. The ethylenically unsaturated compound (A) may be any of a polymerizable monomer, oligomer, and polymer. Furthermore, the ethylenically unsaturated compound may be a monofunctional ethylenically unsaturated compound having one ethylenic double bond in the molecule, or a polyfunctional ethylenically unsaturated compound having two or more ethylenic double bonds in the molecule.

[0033] <Ethylenically unsaturated monomer (A1)> The model material clear composition of the present invention contains, as the ethylenically unsaturated compound (A), an ethylenically unsaturated monomer (A1) having at least one group selected from the group consisting of a dicyclopentenyl group and a dicyclopentanyl group (hereinafter simply referred to as "ethylenically unsaturated monomer (A1)"). For reasons that are unclear, cured products obtained from the ethylenically unsaturated monomer (A1) having at least one group selected from the group consisting of a dicyclopentenyl group and a dicyclopentanyl group tend to be less prone to yellowing when exposed to light such as ultraviolet light during curing. Therefore, by including the ethylenically unsaturated monomer (A1) as a polymerizable compound, the model material composition is less prone to color change (particularly yellowing) when cured by light irradiation, and a model material (stereolithography) with excellent transparency and reduced yellowness can be obtained.

[0034] The ethylenically unsaturated monomer (A1) is not particularly limited as long as it is a polymerizable monomer having at least one group selected from the group consisting of a dicyclopentenyl group and a dicyclopentanyl group and having at least one ethylenic double bond in the molecule, and may be a monofunctional monomer or a polyfunctional monomer. Examples of the ethylenically unsaturated monomer (A1) include (meth)acrylates having at least one group selected from the group consisting of a dicyclopentenyl group and a dicyclopentanyl group. Specific examples include dicyclopentenyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, ethoxylated dicyclopentenyl acrylate, ethoxylated dicyclopentenyl methacrylate, alkoxylated dicyclopentenyl acrylate, alkoxylated dicyclopentenyl methacrylate, dicyclopentanyloxyethyl acrylate, dicyclopentanyloxyethyl methacrylate, ethoxylated dicyclopentanyl acrylate, ethoxylated dicyclopentanyl methacrylate, alkoxylated dicyclopentanyl acrylate, and alkoxylated dicyclopentanyl methacrylate. Among these, (meth)acrylates having at least one group selected from the group consisting of dicyclopentenyl groups and dicyclopentanyl groups are preferred, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentanyl acrylate, and dicyclopentanyloxyethyl acrylate are more preferred, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxyethyl methacrylate, and dicyclopentanyl acrylate are even more preferred, and dicyclopentenyloxyethyl acrylate is particularly preferred. These ethylenically unsaturated monomers (A1) may be used alone or in combination of two or more. In this specification, "(meth)acrylate" refers to either or both of acrylate and methacrylate, and the same applies to "(meth)acrylamide" and the like hereinafter.

[0035] The content of the ethylenically unsaturated monomer (A1) in the model material clear composition of the present invention is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 41% by mass or more, particularly preferably 45% by mass or more, and particularly preferably 50% by mass or more, based on the total mass of the ethylenically unsaturated compounds (A). When the content of the ethylenically unsaturated monomer (A1) relative to the total mass of the ethylenically unsaturated compounds (A) is equal to or greater than the above-mentioned lower limit, the model material clear composition exhibits excellent yellowing suppression effect upon photocuring, and the resulting model material exhibits little yellowness and high transparency. Therefore, from the viewpoint of improving the transparency of the resulting model material, a higher content of the ethylenically unsaturated monomer (A1) is preferable. On the other hand, for example, by adjusting the content in relation to the ethylenically unsaturated compound (A2) or the ethylenically unsaturated monomer (A3), etc., described below, the resulting model material exhibits reduced yellowness, ensuring high transparency, and easily controlling mechanical properties such as strength. Therefore, the content of the ethylenically unsaturated monomer (A1) is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, particularly preferably 70% by mass or less, especially preferably 69% by mass or less, and even more particularly preferably 65% ​​by mass or less, based on the total mass of the ethylenically unsaturated compound (A).

[0036] <Ethylenically unsaturated monomer (A2)> The model material clear composition of the present invention preferably contains, as the ethylenically unsaturated compound (A), an ethylenically unsaturated compound (A2) (hereinafter simply referred to as "ethylenically unsaturated compound (A2)") having an alicyclic structure and a urethane group in the molecule. By containing the ethylenically unsaturated compound (A2), the model material clear composition can easily impart the desired strength to the resulting model material.

[0037] The ethylenically unsaturated compound (A2) is not particularly limited as long as it is a polymerizable compound having an alicyclic structure in the molecule and having at least one urethane group and at least one ethylenic double bond, and may be any of a monomer, an oligomer, and a polymer. In this specification, the alicyclic structure means a structure in which carbon atoms are bonded in a ring and includes a saturated or unsaturated carbon ring that does not have aromaticity, and examples thereof include a cycloalkane skeleton, a cycloalkene skeleton, an adamantane skeleton, a norbornane skeleton, an isophorone skeleton, and a tricyclodecane skeleton.

[0038] Examples of the ethylenically unsaturated compound (A2) include the urethane (meth)acrylates having an alicyclic structure and urethane (meth)acrylate oligomers having an alicyclic structure, as exemplified above. Specific examples include urethane (meth)acrylate oligomers having a dicyclohexylmethane structure, urethane (meth)acrylate oligomers having an isophorone structure, and urethane (meth)acrylate oligomers having a cyclohexylmethane structure. Among these, urethane (meth)acrylate oligomers having an alicyclic structure are preferred, with (meth)acrylate oligomers having a dicyclohexylmethane structure and urethane (meth)acrylate oligomers having an isophorone structure being more preferred, (meth)acrylate oligomers having a dicyclohexylmethane structure being even more preferred, and acrylate oligomers having a dicyclohexylmethane structure being particularly preferred. Using an oligomer as the ethylenically unsaturated compound (A2) makes it easier to obtain a model material with adequate strength. These ethylenically unsaturated compounds (A2) may be used alone or in combination of two or more. In this specification, the term "oligomer" refers to a polymer having a weight average molecular weight (M w The preferred weight average molecular weight (M) of the oligomer is 500 to 10,000. w ) is 800 or more, and more preferably exceeds 1,000. w) means the weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

[0039] The content of the ethylenically unsaturated compound (A2) in the model material clear composition of the present invention is preferably 10% by mass or more, more preferably 11% by mass or more, even more preferably 15% by mass or more, particularly preferably 18% by mass or more, and particularly preferably 20% by mass or more, based on the total mass of the ethylenically unsaturated compounds (A). When the content of the ethylenically unsaturated compound (A2) relative to the total mass of the ethylenically unsaturated compounds (A) is equal to or greater than the above-mentioned lower limit, the strength of the resulting model material is likely to be improved. On the other hand, for example, in order to fully exhibit the effect of suppressing discoloration (yellowing) and improving transparency of the model material by using the ethylenically unsaturated monomer (A1) as a polymerizable compound, the content of the ethylenically unsaturated compound (A2) is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, particularly preferably 35% by mass or less, particularly preferably 29% by mass or less, and even more particularly preferably 25% by mass or less, based on the total mass of the ethylenically unsaturated compounds (A).

[0040] <Mass ratio of (A1) to (A2)> In the model material clear composition of the present invention, the mass ratio of the ethylenically unsaturated monomer (A1) to the ethylenically unsaturated compound (A2) [ethylenically unsaturated monomer (A1) / ethylenically unsaturated compound (A2)] can be appropriately determined depending on the type of polymerizable compound used, the desired mechanical properties of the model material, etc. The mass ratio of the ethylenically unsaturated monomer (A1) to the ethylenically unsaturated compound (A2) is, for example, preferably 1.1 or more, more preferably 1.5 or more, even more preferably 2 or more, and preferably 10 or less, more preferably 8 or less, even more preferably 7 or less, and particularly preferably 5 or less. When the mass ratio of the ethylenically unsaturated monomer (A1) to the ethylenically unsaturated compound (A2) is within the above range, the resulting model material has little yellowness, and is easily imparted with appropriate mechanical properties while ensuring high transparency.

[0041] In addition, when the model material clear composition contains the ethylenically unsaturated monomer (A1), the ethylenically unsaturated compound (A2), or the model material clear composition contains multiple types of the ethylenically unsaturated monomer (A1) and the ethylenically unsaturated compound (A2), it is preferable that the mass ratio of each polymerizable compound in the total mass is within the above range.

[0042] <Ethylenically unsaturated monomer (A3)> The model material clear composition of the present invention preferably contains, as the ethylenically unsaturated compound (A), an ethylenically unsaturated monomer (A3) other than the ethylenically unsaturated monomer (A1) and the ethylenically unsaturated compound (A2) (hereinafter, also referred to simply as "ethylenically unsaturated monomer (A3)"). Like the ethylenically unsaturated compound (A2), the ethylenically unsaturated monomer (A3) easily imparts the desired strength to the model material obtained from the model material clear composition. By using the ethylenically unsaturated compound (A2) in combination with the ethylenically unsaturated monomer (A3), it is possible to sufficiently ensure the effects of suppressing discoloration (yellowing) and improving transparency of the model material, which are achieved by using the ethylenically unsaturated monomer (A1), while easily imparting high strength to the resulting model material. This allows for the production of a model material that has little yellowing, high transparency, excellent appearance characteristics, and appropriate mechanical properties.

[0043] The ethylenically unsaturated monomer (A3) is not particularly limited as long as it is a polymerizable compound having at least one ethylenic double bond in the molecule, different from the ethylenically unsaturated monomer (A1) and the ethylenically unsaturated compound (A2), and may be any of a monomer, an oligomer, and a polymer. In addition, it may be a monofunctional monomer or a polyfunctional monomer. Examples of the ethylenically unsaturated monomer (A3) include monofunctional (meth)acrylates that have an aliphatic cyclic structure other than cyclopentenyl and cyclopentanyl groups and do not contain urethane and amide groups, bifunctional or higher functional (meth)acrylates that have an aliphatic cyclic structure other than cyclopentenyl and cyclopentanyl groups and do not contain urethane and amide groups, ethylenically unsaturated compounds that do not contain an aliphatic cyclic structure in the molecule, such as alkyl (meth)acrylates that have linear or branched alkyl groups, (meth)acrylates that have aromatic or heterocyclic structures in the molecule, and monofunctional ethylenically unsaturated monomers that contain nitrogen atoms, such as (meth)acrylamides and N-vinyl lactams.These ethylenically unsaturated monomers (A3) may be used alone or in combination of two or more. In this specification, an aromatic cyclic structure refers to an aromatic cyclic structure in which carbon atoms are bonded in a ring, and a heterocyclic structure refers to a structure in which carbon atoms and one or more heteroatoms are bonded in a ring.

[0044] In the present invention, the ethylenically unsaturated monomer (A3) is preferably an ethylenically unsaturated monomer that does not have a urethane group, an amide group, an aromatic group, or a vinyl ether group. Furthermore, the ethylenically unsaturated monomer (A3) preferably has at least one group selected from the group consisting of a cyclohexyl group, a 4-t-butylcyclohexyl group, a 3,5,5-trimethylcyclohexyl group, an isobornyl group, a tricyclodecanyl group, a dicyclopentadienyl group, and a 1,4-cyclohexanedimethanol group. It is more preferred that the ethylenically unsaturated monomer (A3) does not contain a urethane group, an amide group, an aromatic group, or a vinyl ether group, and has at least one group selected from the group consisting of a cyclohexyl group, a 4-t-butylcyclohexyl group, a 3,5,5-trimethylcyclohexyl group, an isobornyl group, a tricyclodecanyl group, a dicyclopentadienyl group, and a 1,4-cyclohexanedimethanol group. When the ethylenically unsaturated monomer (A3) has the above structure, the glass transition temperature of the model material clear composition tends to increase, and the desired strength is easily imparted to the obtained model material.

[0045] In the present invention, the ethylenically unsaturated monomer (A3) is preferably an ethylenically unsaturated monomer having a nitrogen atom in the molecule and not having an aliphatic cyclic structure. When the ethylenically unsaturated monomer (A3) has the above structure, the hardness of the obtained model material is likely to be improved. Examples of the ethylenically unsaturated monomer (A3) include (meth)acrylamides, N-vinyllactams, and N-vinylformamide.

[0046] Specific examples of the ethylenically unsaturated monomer (A3) include cyclohexyl acrylate, 4-t-butylcyclohexyl acrylate, 3,5,5-trimethylcyclohexyl acrylate, isobornyl acrylate, tricyclodecane dimethanol diacrylate, dicyclopentadienyl methacrylate, 1,4-cyclohexanedimethanol monoacrylate, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, hydroxyethylacrylamide, hydroxypropylacrylamide, N-vinylpyrrolidone, acryloylmorpholine, N-vinylcaprolactam, hexanediol diacrylate, tripropylene glycol diacrylate, cyclic trimethylolpropane formal acrylate, and phenoxyethyl acrylate. Among these, it is preferable to use one selected from the group consisting of cyclohexyl acrylate, 4-t-butylcyclohexyl acrylate, 3,5,5-trimethylcyclohexyl acrylate, isobornyl acrylate, tricyclodecane dimethanol diacrylate, 1,4-cyclohexane dimethanol monoacrylate, acryloyl morpholine, N-vinyl caprolactam, hexanediol diacrylate, tripropylene glycol diacrylate, cyclic trimethylolpropane formal acrylate, and phenoxyethyl acrylate, and 3,5,5-trimethylcyclohexyl acrylate, isobornyl acrylate, acryloyl morpholine, and tripropylene glycol diacrylate are more preferable. These ethylenically unsaturated monomers (A3) may be used alone or in combination of two or more.

[0047] Among them, acryloylmorpholine is preferred because it has a high glass transition temperature and high curability, which can impart high hardness to the resulting model material.In addition, acryloylmorpholine also functions well as a diluent, so that it can maintain the viscosity of the model material clear composition within a moderate range while incorporating more oligomer components, such as ethylenically unsaturated compounds (A2), which are useful for improving the brittleness resistance of the resulting model material, into the model material clear composition.By including acryloylmorpholine, it is possible to obtain a model material that has a good balance of high hardness and moderate toughness.

[0048] The content of the ethylenically unsaturated monomer (A3) in the model material clear composition of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 21% by mass or more, based on the total mass of the ethylenically unsaturated compounds (A). When the content of the ethylenically unsaturated monomer (A3) relative to the total mass of the ethylenically unsaturated compounds (A) is equal to or greater than the above-mentioned lower limit, the strength of the resulting model material is likely to be improved. On the other hand, for example, in order to fully exhibit the effects of suppressing discoloration (yellowing) and improving transparency of the model material by using the ethylenically unsaturated monomer (A1) as a polymerizable compound, the content of the ethylenically unsaturated monomer (A3) is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, particularly preferably 35% by mass or less, and particularly preferably less than 30% by mass, based on the total mass of the ethylenically unsaturated compounds (A).

[0049] <Mass ratio of (A1) to (A3)> In the model material clear composition of the present invention, the mass ratio of the ethylenically unsaturated monomer (A1) to the ethylenically unsaturated monomer (A3) [ethylenically unsaturated monomer (A1) / ethylenically unsaturated monomer (A3)] can be appropriately determined depending on the type of polymerizable compound used, the desired mechanical properties of the model material, etc. The mass ratio of the ethylenically unsaturated monomer (A1) to the ethylenically unsaturated monomer (A3) is preferably 1.5 or more, more preferably 1.8 or more, even more preferably more than 2, and is preferably 10 or less, more preferably 8 or less, even more preferably 7 or less, and particularly preferably 5 or less. When the mass ratio of the ethylenically unsaturated monomer (A1) to the ethylenically unsaturated monomer (A3) is within the above range, the resulting model material is less likely to have yellowish tinge, is highly transparent, and has well-balanced mechanical properties. In addition, when the model material clear composition contains multiple types of ethylenically unsaturated monomers (A1), (A3), or (A1) and (A3), it is preferable that the mass ratio of each polymerizable compound in the total mass is within the above range.

[0050] <Mass ratio of (A2) to (A3)> In the model material clear composition of the present invention, the mass ratio of the ethylenically unsaturated compound (A2) to the ethylenically unsaturated monomer (A3) [ethylenically unsaturated compound (A2) / ethylenically unsaturated monomer (A3)] can be appropriately determined depending on the type of polymerizable compound used, the desired mechanical properties of the model material, etc. The mass ratio of the ethylenically unsaturated compound (A2) to the ethylenically unsaturated monomer (A3) is preferably 0.5 or more, more preferably 0.8 or more, and is preferably 2.5 or less, more preferably 2 or less, and even more preferably 1.4 or less. When the mass ratio of the ethylenically unsaturated compound (A2) to the ethylenically unsaturated monomer (A3) is within the above range, it is easy to impart appropriate strength to the resulting model material. In addition, when the model material clear composition contains multiple types of ethylenically unsaturated compound (A2), ethylenically unsaturated monomer (A3), or ethylenically unsaturated compound (A2) and ethylenically unsaturated monomer (A3), it is preferable that the mass ratio of each polymerizable compound in the total mass is within the above range.

[0051] <Mass ratio of (A1) to (A2) and (A3)> In the model material clear composition of the present invention, the ratio of the total mass of the ethylenically unsaturated monomer (A1) to the total mass of the ethylenically unsaturated compound (A2) and the ethylenically unsaturated monomer (A3) [ethylenically unsaturated monomer (A1) / ethylenically unsaturated compound (A2)+ethylenically unsaturated monomer (A3)] can be appropriately determined depending on the type of polymerizable compound used, the desired mechanical properties of the model material, etc. This mass ratio is preferably 0.5 or more, more preferably 0.9 or more, even more preferably 1 or more, particularly preferably more than 1, and preferably 4 or less, more preferably 3 or less, and even more preferably 2 or less. When the mass ratio of the ethylenically unsaturated monomer (A1) to the ethylenically unsaturated compound (A2) and the ethylenically unsaturated monomer (A3) is within the above range, the resulting model material can be easily imparted with well-balanced mechanical properties while maintaining high transparency and little yellowing.

[0052] <Polymerizable Compounds Other Than (A)> The model material clear composition of the present invention may contain a polymerizable compound other than the ethylenically unsaturated compound (A) as a polymerizable compound. Examples of such other polymerizable compounds include oxygen-containing cyclic compounds such as oxirane compounds and oxetane compounds, and nitrogen-containing cyclic compounds such as aziridine compounds and acetidine compounds. When the model material clear composition of the present invention contains a polymerizable compound other than the ethylenically unsaturated compound (A), the content of such a polymerizable compound is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on the total mass of the ethylenically unsaturated compound (A).

[0053] <Content of (A)> The content of the ethylenically unsaturated compound (A) used in the model material clear composition of the present invention is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the model material clear composition. When the content of the ethylenically unsaturated compound (A) in the model material clear composition is equal to or greater than the above-mentioned lower limit, a model material clear composition is obtained that is likely to impart high transparency with reduced yellowness and well-balanced mechanical properties to the resulting model material. The upper limit of the content of the ethylenically unsaturated compound (A) is not particularly limited, but is usually 99% by mass or less, preferably 98% by mass or less, based on the total mass of the model material clear composition.

[0054] <Polymerizable compound content> The content of the polymerizable compound used in the model material clear composition of the present invention is preferably 90% by mass or more, more preferably 95% by mass or more, based on the total mass of the model material clear composition, and is preferably 99.9% by mass or less, more preferably 99.5% by mass or less.

[0055] [Additive composition (B)] The model material clear composition of the present invention contains an additive composition (B) containing a specific photopolymerization initiator, a specific polymerization inhibitor, and a specific antioxidant. The inclusion of the additive composition (B) achieves excellent properties, such as the storage stability and curability of the ink, and the transparency of the cured product. In particular, when the contents (mass%) of the initiator, polymerization inhibitor, and antioxidant satisfy the following formulas (1) and (2), the curability of the model material clear composition is ensured and the storage stability is improved, yellowing due to photocuring of the ethylenically unsaturated monomer is suppressed, and high transparency and a crystalline color are easily imparted.

[0056] Photopolymerization initiator content ≥ polymerization inhibitor content ≥ antioxidant content (1) 1≦ [ √Photopolymerization initiator content / √ { (polymerization inhibitor content x 10) 2 + (antioxidant content x 100) 2 }]×100≦800 (2)

[0057] The upper limit of the formula (2) is preferably 760, more preferably 520, and even more preferably 440. When the upper limit of the formula (2) is within the above range, the curability of the model material clear composition is improved, and the model material clear composition can be cured with a smaller integrated light dose. Furthermore, the lower limit of the formula (2) is preferably 1.3, more preferably 6.3, and even more preferably 10.0. When the lower limit of the formula (2) is within the above range, the viscosity change rate of the model material clear composition is small when stored for a long period of time, and the storage stability of the model material clear composition is improved.

[0058] <Photopolymerization initiator> The photopolymerization initiator used in the present invention is at least one selected from the group consisting of α-hydroxyacetophenone-based photopolymerization initiators and acylphosphine oxide-based photopolymerization initiators. The photopolymerization initiator is preferably an initiator that does not absorb visible light or a photopolymerization initiator that loses its yellow color after curing (photobleaching). Specific examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2,2'-dihydroxy-2,2'-dimethyl-1,1'-[methylenebis(4,1-phenylene)]bis(propan-1-one), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide. Among these, at least one selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide is preferred because the model material obtained when the model material clear composition is photocured is less likely to yellow, and the resulting model material has high light resistance and is less likely to yellow over time. These photopolymerization initiators may be used alone or in combination of two or more. Commercially available photopolymerization initiators may also be used, such as Omnirad TPO (manufactured by IGM Resins), Omnirad 819 (manufactured by IGM Resins), and Omnirad 184 (manufactured by IGM Resins).

[0059] The content of the photopolymerization initiator in the model material clear composition is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 3.0% by mass or more, based on the total mass of the model material clear composition, and is preferably 15.0% by mass or less, more preferably 10.0% by mass or less, and even more preferably 5.0% by mass or less. When the content of the photopolymerization initiator is within the above range, unreacted polymerization components can be reduced, sufficiently enhancing the curability of the model material, and yellowing of the model material over time caused by remaining unreacted photopolymerization initiator can be suppressed.

[0060] <Polymerization inhibitor> The polymerization inhibitor of the present invention is a hindered amine polymerization inhibitor (HALS). The polymerization inhibitor can improve the storage stability of the model material clear composition. The polymerization inhibitor can also prevent head clogging caused by the polymerization of a polymerizable compound due to thermal energy. As the polymerization inhibitor, a compound having a piperidine skeleton is preferred, and a compound having a 2,2,6,6-tetramethylpiperidine skeleton is more preferred. Among the above, a compound having a 2,2,6,6-tetramethylpiperidinyloxy group is preferred. Specific examples include 2,2,6,6-tetramethylpiperidine-N-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, esters of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and compounds having two 2,2,6,6-tetramethylpiperidinyloxy groups per molecule, such as bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)sebacate and bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl)decanedioate. Among these, from the viewpoint of improving storage stability, it is preferable to include at least one selected from the group consisting of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl and 2,2,6,6-tetramethylpiperidine 1-oxyl. These polymerization inhibitors may be used alone or in combination of two or more. Commercially available polymerization inhibitors may also be used, such as H-TEMPO (manufactured by Evonik Degussa Japan), IRGASTAB UV-10 (manufactured by BASF), TINUVIN 111 FDL (manufactured by BASF), TINUVIN 144 (manufactured by BASF), and TINUVIN 292 (manufactured by BASF).

[0061] The content of the polymerization inhibitor in the model material clear composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, based on the total mass of the model material clear composition, and is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.0% by mass or less. If the content of the polymerization inhibitor is within the above range, a model material clear composition with higher storage stability and reduced head clogging can be obtained.

[0062] <Antioxidants> The antioxidant of the present invention is a phenolic antioxidant. In the present invention, the phenolic antioxidant means an antioxidant having a phenolic hydroxyl group as a basic skeleton, and examples thereof include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, mono-, di-, or tri-(α-methylbenzyl)phenol, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butyl)phenol, and the like. Phenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4 hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)- 1,3,5-Triazine, pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxy-benzoyl Dilphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis(3,5-di-t-butyl-4-hydroxybenzylphosphonic acid ethyl)calcium, tris-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 2,4-2,4-bis[(octylthio)methyl]o-cresol, N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, tris(2,4-di-t-butylphenyl)phosphite, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octyl Examples of suitable hydroxyphenylbenzotriazole include methyl-3-[3-t-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate condensates with polyethylene glycol (molecular weight approximately 300), hydroxyphenylbenzotriazole derivatives, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl), 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, 4-methoxyphenol, 2,6-di-t-butyl-p-cresol, and 1,4-dihydroxybenzene. Among these, 1,4-dihydroxybenzene, 4-methoxyphenol, and 2,6-di-t-butyl-p-cresol are preferred, and 4-methoxyphenol and 2,6-di-t-butyl-p-cresol are more preferred. The phenolic antioxidant may be used alone or in combination of two or more. Commercially available products may also be used as the phenolic antioxidant, such as hydroquinone monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and butylhydroxytoluene (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0063] The content of the antioxidant in the model material clear composition is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.05% by mass or more, based on the total mass of the model material clear composition, and is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.2% by mass or less. When the content of the antioxidant is within the above range, deterioration of the model material due to discoloration over time caused by oxidation reactions and the like can be suppressed, and a model material with excellent transparency can be achieved.

[0064] The model material clear composition may contain other additives as needed, as long as they do not impair the effects of the present invention. Examples of other additives include surface conditioners, storage stabilizers, UV absorbers, light stabilizers, chain transfer agents, fillers, diluents, thickeners, etc.

[0065] <Surface conditioner> The additive composition (B) may contain a surface conditioner. The surface conditioner is a component that adjusts the surface tension of the model material clear composition within an appropriate range, and the type of surface conditioner is not particularly limited. By adjusting the surface tension of the model material clear composition within an appropriate range, it is possible to stabilize the discharge properties and suppress interfacial mixing between the model material clear composition and the support material composition. As a result, a model material with good dimensional accuracy can be obtained.

[0066] Examples of the surface conditioner include silicone compounds. Examples of the silicone compounds include silicone compounds having a polydimethylsiloxane structure. Specific examples include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, and polyaralkyl-modified polydimethylsiloxane. These include the trade names 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), and TEGO-Rad210. 0, TEGO-Rad2200N, TEGO-Rad2250, TEGO-Rad2300, TEGO-Rad2500, TEGO-Rad2600, TEGO-Rad2700 (all manufactured by Degussa), 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.

[0067] When the model material clear composition contains a surface conditioner, the content thereof is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.05% by mass or more, based on the total mass of the model material clear composition, and is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1.5% by mass or less. When the content of the surface conditioner is within the above range, it is easy to adjust the surface tension of the model material clear composition to an appropriate range.

[0068] Colorant (C) The model material clear composition of the present invention typically does not contain a colorant, but may contain a small amount of a pigment, a dye, or a combination of a pigment and a dye. The colorant content in the model material clear composition of the present invention is typically 0.1% by mass or less, more preferably 0.01% by mass or less, even more preferably 0.001% by mass or less, and particularly preferably 0.0001% by mass or less, based on the total mass of the model material clear composition, with the lower limit being 0% by mass or more. Examples of colorants include colorants with an absorption wavelength in the range of 530 to 620 nm, specifically anthraquinone-based and phthalocyanine-based colorants, such as 1-hydroxy-4-toluidinoanthraquinone, preferably 1-hydroxy-4-toluidinoanthraquinone. These colorants may be used alone or in combination of two or more. Alternatively, two or more colorants may be mixed to have an absorption wavelength in the range of 530 to 620 nm. Furthermore, commercially available products may be used as colorants, such as Quinizarin Blue (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0069] [Characteristics of model material clear composition] The model material clear composition of the present invention is used in material jet stereolithography, and therefore preferably has a viscosity of 1 mPa·s or more and less than 500 mPa·s at 25°C. From the viewpoint of improving dischargeability from the material jet nozzle, the viscosity at 25°C is preferably 10 to 400 mPa·s, more preferably 20 to 300 mPa·s, and even more preferably 25 to 100 mPa·s. The viscosity can be measured in accordance with JIS Z 8803 using an R100 viscometer. The viscosity of the model material clear composition can be controlled by adjusting the type and blending ratio of the polymerizable compound, the type and amount of dilution solvent and thickener, etc.

[0070] Furthermore, the model material clear composition of the present invention preferably exhibits a viscosity change of no more than 10% when stored for 30 days in an environment at 60°C. If the viscosity change rate of the model material clear composition exceeds 10%, the dischargeability of the model material clear composition may deteriorate over time. The viscosity change of the model material clear composition is preferably less than 5%, more preferably less than 3%.

[0071] The surface tension of the model material clear composition of the present invention is preferably 24 to 34 mN / m, more preferably 28 to 30 mN / m. When the surface tension is within this range, droplets can be normally formed from the nozzle even when the material jet is discharged at high speed, making it easier to ensure an appropriate droplet volume and improve modeling accuracy. In the present invention, the surface tension of the model material clear composition can be controlled by adjusting the type and amount of the surface conditioner, etc.

[0072] The method for producing the model material clear composition of the present invention is not particularly limited, and it can be produced, for example, by uniformly mixing the components that make up the model material clear composition using a mixer or stirrer.

[0073] [Material Jet Stereolithography Composition Set] The model material clear composition of the present invention is suitable for producing colorless, highly transparent model materials, and when combined with a model material color composition, can provide model materials with a variety of appearances and surface textures. Therefore, the present invention also covers a material jet stereolithography composition set comprising the model material clear composition of the present invention and a model material color composition used in material jet stereolithography.

[0074] [Model material color composition] The model material clear composition of the present invention can be used in combination with various conventionally known model material color compositions. A model material color composition that can be suitably used together with the model material clear composition of the present invention includes an ethylenically unsaturated monomer (D), preferably a model material color composition containing 30% by mass or more and 85% by mass or less of a (meth)acrylate-based ethylenically unsaturated monomer (D1) and 10% by mass or more and 50% by mass or less of a nitrogen-containing ethylenically unsaturated monomer (D2) that is not a (meth)acrylate-based compound, based on the total mass of the model material color composition.

[0075] The model material color composition included in the material jet stereolithography composition set of the present invention contains an ethylenically unsaturated monomer (D). The ethylenically unsaturated monomer (D) is a polymerizable monomer having at least one ethylenic double bond in the molecule, which has the property of being cured by energy rays. The ethylenically unsaturated monomer (D) may be a monofunctional ethylenically unsaturated monomer having one ethylenic double bond in the molecule, or a polyfunctional ethylenically unsaturated monomer having two or more ethylenic double bonds in the molecule. Examples of the ethylenically unsaturated monomer (D) include (meth)acrylate, (meth)acrylamide, N-vinyl lactam, vinyl ether, and maleimide.

[0076] The model material color composition included in the material jet stereolithography composition set of the present invention preferably contains a (meth)acrylate-based ethylenically unsaturated monomer (D1) (hereinafter simply referred to as "ethylenically unsaturated monomer (D1)") as the ethylenically unsaturated monomer (D). The ethylenically unsaturated monomer (D1) may be a monofunctional (meth)acrylate (monofunctional ethylenically unsaturated monomer) or a polyfunctional (meth)acrylate (polyfunctional ethylenically unsaturated monomer). Examples of the (meth)acrylate include alkyl (meth)acrylates having a linear or branched alkyl group, (meth)acrylates having an aliphatic cyclic structure and / or an aromatic cyclic structure in the molecule, (meth)acrylates having a heterocyclic structure, (meth)acrylates having a linear or branched alkylene group, and alkylene glycol (meth)acrylates having a linear or branched alkylene glycol group. These may be used alone or in combination of two or more.

[0077] The linear or branched alkyl group in the alkyl(meth)acrylate is preferably an alkyl group having 4 to 30 carbon atoms, more preferably 6 to 25 carbon atoms, and specific examples thereof include an octyl group, an isooctyl group, a 2-ethylhexyl group, a nonyl group, an isononyl group, a lauryl group, a stearyl group, an isostearyl group, a t-butyl group, etc. The alkyl(meth)acrylate is usually a monofunctional (meth)acrylate.

[0078] The (meth)acrylate having an aliphatic cyclic structure and / or an aromatic cyclic structure has an alicyclic group and / or an aromatic hydrocarbon group in the molecule, and these groups include alicyclic groups and aromatic hydrocarbon groups preferably having 6 to 20 carbon atoms, more preferably 8 to 14 carbon atoms. Examples of the alicyclic group include a cyclohexyl group, a 4-t-butylcyclohexyl group, an isobornyl group, a dicyclopentanyl group, a tricyclodecyl group, and an adamantyl group. Examples of the aromatic hydrocarbon group include a phenoxyethyl group, an ethoxylated phenyl group (e.g., 2-(2-ethoxyethoxy)phenyl), a phenylphenol group, and a fluorene group. The (meth)acrylate having an aliphatic cyclic structure and / or an aromatic cyclic structure may be either monofunctional or polyfunctional, but is preferably a monofunctional (meth)acrylate.

[0079] The (meth)acrylate having a heterocyclic structure has a heterocyclic group in the molecule, and the heterocyclic group preferably has 5 to 20 carbon atoms, more preferably 5 to 14 carbon atoms. Examples of the (meth)acrylate having a heterocyclic structure include tetrahydrofurfuryl (meth)acrylate, 4-(meth)acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, and 4-(meth)acryloyloxymethyl-2-cyclohexyl-1,3-dioxolane. The (meth)acrylate having a heterocyclic structure may be either monofunctional or polyfunctional, but is preferably a monofunctional (meth)acrylate.

[0080] The alkylene group in the (meth)acrylate having a linear or branched alkylene group preferably has 2 to 30 carbon atoms, more preferably 3 to 20 carbon atoms. Examples of such alkylene groups include pentaerythritol, dipentaerythritol, and dimethyloltricyclodecane. Specific examples of the (meth)acrylate having a linear or branched alkylene group include pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and dimethyloltricyclodecane di(meth)acrylate. The (meth)acrylate having a linear or branched alkylene group is usually a polyfunctional (meth)acrylate, preferably a polyfunctional (meth)acrylate having 2 to 10, and more preferably 2 to 6 (meth)acrylate groups.

[0081] The alkylene glycol group in the (meth)acrylate having a linear or branched alkylene glycol group is preferably an alkylene glycol group having 4 to 25 carbon atoms, more preferably 6 to 20 carbon atoms. Examples of the alkylene glycol group include (n) ethylene glycol groups such as tripropylene glycol group, 1,6-hexanediol group, neopentyl glycol group, 1,9-nonanediol group, 3-methyl-1,5-pentanediol group, 2-n-butyl-2-ethyl-1,3-propanediol group, pentaerythritol group, diethylene glycol group, and triethylene glycol group, and (n) propylene glycol groups such as dipropylene glycol group and tripropylene glycol group. Specific examples of the (meth)acrylate having a linear or branched alkylene glycol group include di(meth)acrylates of the above alkylene glycols and tri(meth)acrylates of the above alkylene glycols. The (meth)acrylate having a linear or branched alkylene glycol group may be either monofunctional or polyfunctional, but is preferably a polyfunctional (meth)acrylate, more preferably a polyfunctional (meth)acrylate having 1 to 6, and even more preferably 2 or 3 (meth)acrylate groups.

[0082] From the viewpoint of reducing the viscosity of the composition and facilitating improved ejection properties in the material jet, and from the viewpoint of facilitating improved strength and hardness of the resulting model material, the model material color composition preferably contains, as the ethylenically unsaturated monomer (D1), a (meth)acrylate-based ethylenically unsaturated monomer having an aliphatic cyclic structure and / or an aromatic cyclic structure, more preferably a (meth)acrylate-based ethylenically unsaturated monomer having an aliphatic cyclic structure, and even more preferably isobornyl (meth)acrylate and / or cyclohexyl (meth)acrylate.

[0083] The content of the ethylenically unsaturated monomer (D1) in the model material color composition is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, particularly preferably 45% by mass or more, based on the total mass of the model material color composition, and is preferably 85% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, particularly preferably 65% ​​by mass or less. When the content of the ethylenically unsaturated monomer (D1) is above the lower limit, the viscosity of the model material color composition is easily controlled, and good dischargeability from the nozzle is easily ensured. When the content of the ethylenically unsaturated monomer (D1) is below the upper limit, the resulting model material is easily imparted with high strength and hardness, and its dimensional stability is easily improved.

[0084] The model material color composition included in the material jet stereolithography composition set of the present invention preferably contains, as the ethylenically unsaturated monomer (D), a nitrogen atom-containing ethylenically unsaturated monomer (D2) (hereinafter simply referred to as "nitrogen atom-containing ethylenically unsaturated monomer (D2)") that is not a (meth)acrylate-based compound. In this specification, the ethylenically unsaturated monomer (D2) is not a (meth)acrylate, and a (meth)acrylate containing a nitrogen atom is not included in the nitrogen atom-containing ethylenically unsaturated monomer (D2).

[0085] The nitrogen atom-containing ethylenically unsaturated monomer (D2) contained in the model material color composition may be a monofunctional nitrogen atom-containing ethylenically unsaturated monomer (monofunctional ethylenically unsaturated monomer) or a polyfunctional nitrogen atom-containing ethylenically unsaturated monomer (polyfunctional ethylenically unsaturated monomer). Examples of the nitrogen atom-containing ethylenically unsaturated monomer (D2) include (meth)acrylamides, N-vinyl lactams, maleimide, and N-vinylformamide. These may be used alone or in combination of two or more.

[0086] As the (meth)acrylamide, a compound represented by the following formula (3):

[0087] [ka] [In the formula, Q 1 represents an n-valent linking group, and Q 2 each independently represents a hydrogen atom or a monovalent organic group, and R 1 each independently represents a hydrogen atom or a methyl group, and n represents an integer of 1 or 2 or more. and a monofunctional or polyfunctional (meth)acrylamide compound represented by the following formula (4):

[0088] [ka] [In the formula, Q 3 represents a divalent linking group which may have a substituent and which forms an alicyclic structure together with the N atom, R 1 represents a hydrogen atom or a methyl group] The (meth)acrylamides are preferably monofunctional compounds, from the viewpoint of appropriately lowering the viscosity of the model material color composition and easily improving the dischargeability.

[0089] The monofunctional compound represented by formula (3) or formula (4) includes, for example, Q 1 is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and Q 2is preferably a linear or branched alkyl group having 1 to 10 carbon atoms and / or a hydrogen atom (e.g., N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, etc.), 1 preferably has a linear or branched hydroxyalkyl group having 2 to 10 carbon atoms, and Q 2 Hydroxyalkyl(meth)acrylamides in which Q is a hydrogen atom (e.g., hydroxyethylacrylamide, hydroxypropylacrylamide, etc.), 1 preferably has an alicyclic group having 3 to 20 carbon atoms, and Q 2 is preferably a linear or branched alkyl group having 1 to 10 carbon atoms and / or a hydrogen atom; 3 However, preferred examples include (meth)acrylamides having 4 to 20 carbon atoms and constituting an alicyclic group [for example, acryloylmorpholine].

[0090] The N-vinyl lactam may be either monofunctional or polyfunctional, and examples thereof include the following formula (5):

[0091] [ka] [wherein m represents an integer of 1 to 5] From the viewpoint of easy availability of raw materials, m is preferably an integer of 2 to 4, and more preferably 2 or 4. Specific examples of such N-vinyl lactams include N-vinylpyrrolidone and N-vinylcaprolactam.

[0092] From the viewpoint of easily increasing the strength and hardness of the resulting model material, the model material color composition preferably contains, as the nitrogen atom-containing ethylenically unsaturated monomer (D2), at least one selected from the group consisting of (meth)acrylamides and N-vinyllactams, more preferably (meth)acrylamides, and even more preferably Q in formula (4) 3The (meth)acrylamides having 4 to 20 carbon atoms and constituting an alicyclic group are particularly preferred, and acryloylmorpholine is particularly preferred.

[0093] The content of the nitrogen-atom-containing ethylenically unsaturated monomer (D2) in the model material color composition is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on the total mass of the model material color composition, and is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. When the content of the nitrogen-atom-containing ethylenically unsaturated monomer (D2) is above the above-mentioned lower limit, the resulting model material is easily imparted with high strength and hardness, and dimensional stability is easily improved. Furthermore, when the content of the nitrogen-atom-containing ethylenically unsaturated monomer (D2) is below the above-mentioned upper limit, the viscosity of the model material color composition is easily controlled, and good dischargeability from a nozzle is easily ensured.

[0094] The model material color composition included in the material jet stereolithography composition set of the present invention preferably contains, as the ethylenically unsaturated monomer (D), a monofunctional ethylenically unsaturated monomer and a di- or higher functional ethylenically unsaturated monomer. Examples of the monofunctional ethylenically unsaturated monomer include the monofunctional (meth)acrylates and monofunctional nitrogen-containing ethylenically unsaturated monomers described above. Examples of the di- or higher functional ethylenically unsaturated monomer include the polyfunctional (meth)acrylates and polyfunctional nitrogen-containing ethylenically unsaturated monomers described above. When the model material color composition included in the material jet stereolithography composition set of the present invention contains a di- or higher functional ethylenically unsaturated monomer in addition to the monofunctional ethylenically unsaturated monomer, the toughness and strength of the resulting model material are likely to be improved.

[0095] The content of the monofunctional ethylenically unsaturated monomer in the model material color composition is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, based on the total mass of the model material color composition. When the content of the monofunctional ethylenically unsaturated monomer in the model material color composition is equal to or greater than the lower limit, the viscosity of the model material color composition is reduced, and the dischargeability is easily improved. When the content of the monofunctional ethylenically unsaturated monomer is equal to or less than the upper limit, the strength and hardness of the resulting model material are easily increased, and the stickiness of the surface of the model material is easily suppressed.

[0096] The content of the difunctional or higher ethylenically unsaturated monomer in the model material color composition is preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more, based on the total mass of the model material color composition, and is also preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less. When the content of the difunctional or higher ethylenically unsaturated monomer in the model material color composition is above the lower limit, the toughness of the resulting model material is likely to be improved, and well-balanced mechanical properties are likely to be imparted to the model material. Furthermore, when the content of the difunctional or higher ethylenically unsaturated monomer is below the upper limit, cure shrinkage during photocuring of the model material color composition is likely to be suppressed, and the dimensional accuracy (or warpage resistance) of the resulting model material is likely to be improved.

[0097] In a preferred embodiment of the present invention, the model material color composition preferably contains the monofunctional (meth)acrylate, preferably having an alicyclic structure, described above, a polyfunctional (meth)acrylate, and a monofunctional nitrogen-containing ethylenically unsaturated monomer. When the model material color composition contains a monofunctional (meth)acrylate having an alicyclic structure and a polyfunctional (meth)acrylate, the viscosity of the composition is reduced, which facilitates improved dischargeability. At the same time, the toughness of the resulting model material is improved, and well-balanced mechanical properties are readily imparted to the model material. Furthermore, when the model material color composition contains a monofunctional nitrogen-containing ethylenically unsaturated monomer, the strength of the resulting model material is readily improved.

[0098] In this embodiment, from the viewpoint of easily achieving the above-mentioned effects, the content of the monofunctional (meth)acrylate having an aliphatic cyclic structure in the model material color composition is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 75% by mass or less, more preferably 60% by mass or less, based on the total mass of the model material color composition. Furthermore, the content of the polyfunctional (meth)acrylate is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, based on the total mass of the model material color composition. Furthermore, the content of the monofunctional nitrogen atom-containing ethylenically unsaturated monomer is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less.

[0099] The model material color composition included in the material jet stereolithography composition set of the present invention preferably further contains a polymerizable oligomer. The inclusion of a polymerizable oligomer in the model material color composition improves the toughness of the model material, ensuring well-balanced mechanical strength, resulting in a model material that is less likely to break when bent. It also reduces the tackiness of the surface of the model material.

[0100] Examples of polymerizable oligomers include epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, and urethane (meth)acrylate oligomers. These may be used alone or in combination of two or more. A polymerizable oligomer that is preferably used is preferably a polymerizable oligomer having a urethane group, more preferably a urethane (meth)acrylate oligomer, from the viewpoints of being able to impart strength and toughness to the resulting model material, and of being able to select materials with a wide range of properties from a wide range of materials.

[0101] The polymerizable oligomer having a urethane group is preferably a caprolactone-modified polymerizable oligomer, from the viewpoints of easily designing the viscosity of the model material color composition to be low, easily increasing the hardness and strength of the resulting model material, and easily reducing cure shrinkage.When the model material color composition contains a polymerizable oligomer, the polymerizable oligomer is preferably a caprolactone-modified isophorone diisocyanate-based polymerizable oligomer, from the viewpoint of easily increasing the hardness and strength of the resulting model material.

[0102] When the model material color composition contains a polymerizable oligomer, the content thereof is preferably 10% by mass or more, more preferably 15% by mass or more, and preferably 45% by mass or less, more preferably 30% by mass or less, based on the total mass of the model material color composition. When the content of the polymerizable oligomer is equal to or greater than the lower limit, the tackiness of the model material surface is easily reduced. When the content of the polymerizable oligomer is equal to or less than the upper limit, the model material color composition can be easily discharged with ease.

[0103] The model material color composition may contain other additives as needed, provided that they do not impair the effects of the present invention. Examples of other additives include photopolymerization initiators, surface conditioners, storage stabilizers, antioxidants, colorants, UV absorbers, light stabilizers, polymerization inhibitors, chain transfer agents, and fillers. These components are not particularly limited, and known compounds conventionally used in the relevant field can be appropriately selected and used. As photopolymerization initiators and storage stabilizers, the same photopolymerization initiators and storage stabilizers as those exemplified above for the model material clear composition can also be suitably used in the model material color composition in the same amounts. The additives contained in the model material clear composition and the additives contained in the model material color composition may be the same or different.

[0104] Examples of surface conditioners that the model material color composition may contain include those listed above as examples of surface conditioners that the model material clear composition may contain. When the model material color composition contains a surface conditioner, the content is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.05% by mass or more, based on the total mass of the model material color composition, and is preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less. When the content of the surface conditioner is within the above range, it is easy to control the surface tension of the model material color composition within an appropriate range.

[0105] Both the model material clear composition and the model material color composition constituting the material jet stereolithography composition set of the present invention preferably contain a surface conditioner. In this case, the amount of surface conditioner contained in the model material color composition (the content (mass %) of the surface conditioner relative to the total mass of the model material color composition) is preferably less than the amount of surface conditioner contained in the model material clear composition (the content (mass %) of the surface conditioner relative to the total mass of the model material clear composition). If the amount of surface conditioner contained in the model material color composition is less than the amount of surface conditioner contained in the model material clear composition, repulsion between the model material clear composition and the model material color composition at the interface between the two compositions is suppressed. This results in a clearer boundary between the clear model material and the color model material in the resulting model material, allowing for the production of a model material with excellent appearance. In this case, the amount of surface conditioner contained in the model material color composition can be determined appropriately depending on the types and ratios of the polymerizable compounds constituting the model material color composition and the model material clear composition. In one embodiment of the present invention, the amount (mass %) of the surface conditioner contained in the model material color composition is preferably 30% or more, more preferably 35% or more, even more preferably 40% or more, relative to the amount (mass %) of the surface conditioner contained in the model material clear composition of the present invention, and is preferably 85% or less, more preferably 70% or less, even more preferably 60% or less.

[0106] The model material color composition in the material jet stereolithography composition set of the present invention is typically a colored composition containing a pigment. While the composition of the model material color composition is not particularly limited, the composition preferably contains cyan, magenta, and yellow, and more preferably further contains white and / or black.

[0107] From the viewpoints of color tone, color development, and ease of pigment dispersion, cyan preferably contains at least one pigment selected from the group consisting of CI Pigment Blue 15:3 and CI Pigment Blue 15:4.

[0108] From the viewpoints of color tone, color development, and ease of pigment dispersion, it is preferable that the magenta contains at least one pigment selected from the group consisting of CI Pigment Red 122, CI Pigment Red 202, and CI Pigment Violet 19.

[0109] From the viewpoints of color tone, color development, and ease of pigment dispersion, it is preferable that the yellow contains at least one pigment selected from the group consisting of CI Pigment Yellow 150 and CI Pigment Yellow 155.

[0110] From the viewpoints of color tone, hiding power, and ease of pigment dispersion, the white preferably contains titanium oxide. From the viewpoint of easily improving the light stability of the ink, the titanium oxide is more preferably rutile titanium oxide.

[0111] The black preferably contains carbon black from the viewpoints of color tone, color development, and ease of pigment dispersion.

[0112] The content of the pigment in the model material color composition may be appropriately set depending on the desired color of the model material color composition and the type of pigment used, but is usually 0.1% by mass or more, more preferably 0.2% by mass or more, based on the total mass of the model material color composition. There is no particular upper limit to the content of the pigment in the model material color composition, and it is usually 5% by mass or less, preferably 3% by mass or less, based on the total mass of the model material color composition.

[0113] The viscosity of the model material color composition is preferably 1 mPa·s or more and less than 500 mPa·s at 25°C for use in material jet stereolithography. To ensure good dischargeability from the material jet nozzle, the viscosity at 25°C is preferably 10 to 400 mPa·s, more preferably 20 to 300 mPa·s, and even more preferably 25 to 100 mPa·s. The viscosity can be measured in accordance with JIS Z 8803 using an R100 viscometer. The viscosity of the model material color composition can be controlled by adjusting the type and blending ratio of the polymerizable compound, the type and amount of dilution solvent and thickener, etc.

[0114] The surface tension of the model material color composition of the present invention is preferably 24 to 34 mN / m, more preferably 28 to 30 mN / m. When the surface tension is within the above range, droplets can be normally formed from the nozzle even when the material jet is discharged at high speed, making it easier to ensure an appropriate droplet volume and improve modeling accuracy. In the present invention, the surface tension of the model material color composition can be controlled by adjusting the type and amount of the surface conditioner.

[0115] In the present invention, the method for producing the model material color composition is not particularly limited, and the model material color composition can be produced, for example, by uniformly mixing the components constituting the model material color composition using a mixing and stirring device or the like.

[0116] [Support material composition] Furthermore, in order to model complex or intricate shapes with high precision, the model material clear composition of the present invention is preferably used in combination with a support material for supporting the model material during three-dimensional modeling. Accordingly, the present invention also covers a material jet stereolithography composition set comprising the model material clear composition of the present invention and a support material composition for modeling the support material by material jet stereolithography.

[0117] The support material composition is a photocurable composition for a support material that provides a support material upon photocuring. After producing a model material, the support material can be removed from the model material by physically peeling it off or by dissolving it in an organic solvent or water. The model material clear composition and material jet stereolithography composition set of the present invention can be used in combination with various compositions conventionally known as support material compositions. The support material composition constituting the stereolithography composition set of the present invention is preferably water-soluble, since this allows for easy removal of the support material without damaging the model material, is environmentally friendly, and allows for clean and detailed removal of the support material.

[0118] Such water-soluble support material compositions include, for example, those containing a monofunctional ethylenically unsaturated monomer and a polyalkylene glycol having at least one group selected from the group consisting of an oxyethylene group and an oxypropylene group.

[0119] The monofunctional ethylenically unsaturated monomer contained in the support material composition is a polymerizable monomer having one ethylenic double bond in the molecule and capable of being cured by energy rays, and is preferably a water-soluble monofunctional ethylenically unsaturated monomer. Examples of the monofunctional ethylenically unsaturated monomer contained in the support material composition include hydroxyl group-containing (meth)acrylates having 2 to 15 carbon atoms [e.g., hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.], hydroxyl group-containing (meth)acrylates having a number average molecular weight (Mn) of 200 to 1,000 [e.g., polyethylene glycol mono(meth)acrylate, monoalkoxy (carbon number 1 to 4) polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, monoalkoxy (carbon number 1 to 4) polypropylene glycol mono(meth)acrylate, etc.], and the like. (meth)acrylate, mono(meth)acrylate of PEG-PPG block polymer, etc.), (meth)acrylamide derivatives having 3 to 15 carbon atoms [for example, (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)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, N-hydroxybutyl(meth)acrylamide, etc.], (meth)acryloylmorpholine, etc. These may be used alone or in combination of two or more.

[0120] The content of the monofunctional ethylenically unsaturated monomer in the support material composition is preferably 20% by mass or more, more preferably 25% by mass or more, based on the total amount of the support material composition, from the viewpoints of improving the curability of the support material composition and facilitating rapid dissolution in water of the support material obtained by photocuring the support material composition. Furthermore, the content is preferably 50% by mass or less, more preferably 45% by mass or less.

[0121] The support material composition preferably contains a polyalkylene glycol containing at least one group selected from the group consisting of an oxyethylene group and an oxypropylene group. The polyalkylene glycol containing at least one group selected from the group consisting of an oxyethylene group and an oxypropylene group is an active hydrogen compound to which at least one group selected from the group consisting of ethylene oxide and propylene oxide is added. Examples of polyalkylene glycols include polyethylene glycol and polypropylene glycol. These may be used alone or in combination of two or more. Examples of active hydrogen compounds include monohydric to tetrahydric alcohols and amine compounds. Among these, dihydric alcohols or water are preferred.

[0122] The content of the polyalkylene glycol in the support material composition is preferably 20% by mass or more, more preferably 25% by mass or more, based on the total amount of the support material composition, from the viewpoint of easily increasing the solubility in water of the support material obtained by photocuring the support material composition. Furthermore, the content is preferably 49% by mass or less, more preferably 45% by mass or less, from the viewpoint of easily preventing the phenomenon of polyalkylene glycol leaching out of the support material during the modeling of a three-dimensional object and easily increasing the precision of the modeling.

[0123] The number average molecular weight (M n ) of the polyalkylene glycol is preferably 100 to 5,000. n When (M) of the polyalkylene glycol is within the above range, the polyalkylene glycol is compatible with the polyalkylene glycol before photocuring, but is poorly compatible with the polyalkylene glycol after photocuring. As a result, the support material obtained by photocuring the support material composition can have improved self-supporting properties and can also have improved solubility in water. n ) is preferably 200 to 3,000, more preferably 400 to 2,000.

[0124] The support material composition may contain other additives as needed, such as a photopolymerization initiator, a water-soluble organic solvent, an antioxidant, a colorant, a pigment dispersant, a storage stabilizer, an ultraviolet absorber, a light stabilizer, a polymerization inhibitor, a chain transfer agent, and a filler.

[0125] The photopolymerization initiator may be the same as the compounds exemplified above as photopolymerization initiators that can be contained in the model material clear composition. When the support material composition contains a photopolymerization initiator, the content is preferably 2% by mass or more, more preferably 3% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, based on the total amount of the support material composition. When the content of the photopolymerization initiator is within the above range, unreacted polymerization components are reduced, making it easy to sufficiently enhance the curability of the support material.

[0126] The water-soluble organic solvent is a component that improves the solubility in water of the support material obtained by photocuring the support material composition. It is also a component that can adjust the viscosity of the support material composition to a low level. When the support material composition contains a water-soluble organic solvent, the content is preferably 35% by mass or less, more preferably 30% by mass or less, based on the total amount of the support material composition. Furthermore, the content is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. If the amount of water-soluble organic solvent in the support material composition is too high, the water-soluble organic solvent may seep out when the support material composition is photocured, which may result in a deterioration in the dimensional accuracy of the model material formed on the upper layer of the support material. When the content of the water-soluble organic solvent is equal to or less than the above-mentioned upper limit, such seepage is easily suppressed. When the content of the water-soluble organic solvent in the support material composition is equal to or greater than the above-mentioned lower limit, it is easy to improve the removability of the support material with water and to control the viscosity of the support material composition to a low level.

[0127] Examples of the water-soluble organic solvent include alkylene glycol monoacetates having a linear or branched alkylene group [e.g., ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate, dipropylene glycol monoacetate, triethylene glycol monoacetate, tripropylene glycol monoacetate, tetraethylene glycol monoacetate, tetrapropylene glycol monoacetate, etc.], alkylene glycol monoalkyl ethers having a linear or branched alkylene group [e.g., ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, tetrapropylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, ethyl ether, triethylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monopropyl ether, diethylene glycol monopropyl ether, dipropylene glycol monopropyl ether, triethylene glycol monopropyl ether, tripropylene glycol monopropyl ether, tetraethylene glycol monopropyl ether, tetrapropylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether, triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether, etc.], alkylene glycol diacetates having a linear or branched alkylene group [for example, ethylene glycol diacetate,propylene glycol diacetate, diethylene glycol diacetate, dipropylene glycol diacetate, triethylene glycol diacetate, tripropylene glycol diacetate, tetraethylene glycol diacetate, tetrapropylene glycol diacetate, etc.], alkylene glycol dialkyl ethers having a linear or branched alkylene group [for example, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, triethylene glycol dimethyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrapropylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol diethyl ether, diethylene glycol diethyl ether, dipropylene glycol diethyl ether, triethylene glycol diethyl ether, tripropylene glycol diethyl ether, tetraethylene glycol diethyl ether, tetrapropylene glycol diethyl ether, ethylene glycol ethanol dipropyl ether, propylene glycol dipropyl ether, diethylene glycol dipropyl ether, dipropylene glycol dipropyl ether, triethylene glycol dipropyl ether, tripropylene glycol dipropyl ether, tetraethylene glycol dipropyl ether, tetrapropylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dibutyl ether, diethylene glycol dibutyl ether, dipropylene glycol dibutyl ether, triethylene glycol dibutyl ether, tripropylene glycol dibutyl ether, tetraethylene glycol dibutyl ether, tetrapropylene glycol dibutyl ether, etc.], alkylene glycol monoalkyl ether acetates having a linear or branched alkylene group [for example, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether acetate,Tripropylene glycol monomethyl ether acetate, tetraethylene glycol monomethyl ether acetate, tetrapropylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monoethyl ether acetate, triethylene glycol monoethyl ether acetate, tripropylene glycol monoethyl ether acetate, tetraethylene glycol monoethyl ether acetate, tetrapropylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, propylene glycol monopropyl ether acetate, diethylene glycol monopropyl ether acetate acetate, dipropylene glycol monopropyl ether acetate, triethylene glycol monopropyl ether acetate, tripropylene glycol monopropyl ether acetate, tetraethylene glycol monopropyl ether acetate, tetrapropylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monobutyl ether acetate, triethylene glycol monobutyl ether acetate, tripropylene glycol monobutyl ether acetate, tetraethylene glycol monobutyl ether acetate, tetrapropylene glycol monobutyl ether acetate, etc. These may be used alone or in combination of two or more. Among these, from the viewpoints of easily improving the removability of the support material with water and easily controlling the viscosity of the support material composition to be low, it is more preferable that the water-soluble organic solvent be triethylene glycol monomethyl ether or dipropylene glycol monomethyl ether acetate.

[0128] From the viewpoint of improving dischargeability from a material jet nozzle, the viscosity of the support material composition in the present invention is preferably 1 to 500 mPa·s at 25° C., more preferably 10 to 400 mPa·s, and even more preferably 25 to 100 mPa·s. The viscosity can be measured in accordance with JIS Z 8 803 using an R100 type viscometer.

[0129] 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 that make up the support material composition using a mixer or stirrer.

[0130] [Method of manufacturing optically modeled objects] Using the model material clear composition or the material jet stereolithography composition set of the present invention, a three-dimensional object (model material or stereolithography product) can be produced by a material jet type stereolithography method.

[0131] The method for producing a stereolithography object is not particularly limited as long as it is a method for producing a three-dimensional object by a material jet stereolithography method using the model material clear composition or the stereolithography composition set of the present invention, and any known method can be used. For example, a model material that is a three-dimensional object can be obtained by a method including the steps of photocuring a model material clear composition to obtain a model material and photocuring a support material composition to obtain a support material, and removing the support material from the model material.

[0132] In the manufacturing method, for example, based on 3D CAD data of the object to be produced, data on a model material clear composition that is layered using the material jet method to form a three-dimensional object, and data on a support material composition that supports the three-dimensional object in the process of being produced, are prepared; slice data for discharging each composition using a material jet 3D printer is then prepared; the compositions for the model material and the support material are then discharged based on the prepared slice data, and a photo-curing process is repeated for each layer, thereby producing a photo-cured object consisting of a cured product of the model material clear composition (model material) and a cured product of the support material composition (support material).

[0133] Examples of light for curing the model material clear 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.

[0134] Examples of light sources include conventionally known high-pressure mercury lamps, metal halide lamps, and UV-LEDs. Among these, LEDs are preferred from the viewpoints of miniaturizing the equipment and reducing power consumption. The light intensity is set to 200 to 1000 mJ / cm from the viewpoints of hardness and dimensional accuracy of the model material. 2 When a UV-LED is used as the light source, it is preferable to use one with a central wavelength of 385 to 415 nm, since this allows the light to reach deep layers more easily and improves the hardness and dimensional accuracy of the resulting model material.

[0135] The thickness of each layer constituting the three-dimensional 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.

[0136] The resulting three-dimensional object is a combination of model material and support material. The support material can be removed from the three-dimensional object to obtain a three-dimensional object that is the model material. The support material is preferably removed by, for example, immersing the resulting three-dimensional object in a removal solvent that dissolves the support material, softening the support material, and then removing the support material from the surface of the model material with a brush or the like. The solvent for removing the support 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.

[0137] [Photocured product] The photocured product of the model material clear composition of the present invention exhibits a highly transparent and crystalline color with reduced yellowness. * value is 90 or more, preferably 95 or more, * a value of -2 or more and less than 2, preferably -1 or more and less than 1, * The value is -10 or more and less than 4, preferably -5 or more and less than 2, more preferably -2 or more and less than 1. * represents brightness, and L * The value ranges from 0 to 100, where 0 represents black and 100 represents white; * represents the red to green range, and b * represents the range from blue to yellow, and a * and b * The range of both is +60 to -60, where +60a * is red, gradually -60a * and turns green; similarly, +60b * is yellow, -60b * is blue. The Lab color difference value can be measured using a spectrophotometer, for example, a "CM-5" (trade name) manufactured by Konica Minolta.

[0138] The photocured product of the model material clear composition of the present invention is highly transparent. The transparency of the photocured product of the model material clear composition can be evaluated by measuring the total light transmittance using a turbidity meter, for example, the "NDH2000" (trade name) manufactured by Nippon Denshoku Industries Co., Ltd. The photocured product of the model material clear composition of the present invention has a total light transmittance of 80 or more, preferably 85 or more, at a thickness of 2 mm. [Example]

[0139] The present invention will be described in more detail below with reference to examples. In the examples, "%" means % by mass unless otherwise specified.

[0140] [(1) Model material clear composition] (1-1. Preparation of model material clear composition) Table 1 shows details of the components constituting the model material clear composition used in the examples and comparative examples.

[0141] [Table 1]

[0142] According to the compositions shown in Tables 2 to 4 below, the components constituting each model material clear composition were uniformly mixed and stirred using a mixer / stirrer to prepare each of the model material clear compositions of Examples 1 to 22 and Comparative Examples 1 to 4.

[0143] [Table 2]

[0144] [Table 3]

[0145] [Table 4]

[0146] (1-2. Evaluation method for model material clear composition) The viscosity, storage stability, and curing properties of each of the model material clear compositions of Examples 1 to 22 and Comparative Examples 1 to 4 were evaluated according to the methods described below. The evaluation results are shown in Tables 5 and 6.

[0147] <1-2-1. Viscosity evaluation method> The viscosity (unit: mPa s) of the prepared model material clear composition was measured using an R100 viscometer (manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C and a cone rotation speed of 5 rpm according to the method in accordance with JIS Z8803. The viscosity measured at this time was taken as the initial viscosity and was used to evaluate the viscosity change rate below.

[0148] <1-2-2. Viscosity change rate evaluation method> The model material clear composition whose viscosity had been measured was stored in a sealed glass bottle at 60°C for 30 days, and the viscosity of the composition after storage was measured. The viscosity change rate was calculated from the measured viscosity before and after storage. The viscosity change rate was calculated using the following formula.

[0149] Viscosity change rate (%) = {(viscosity after storage - initial viscosity) / (initial viscosity)} x 100

[0150] The measured viscosity change rate was evaluated according to the following evaluation criteria.

[0151] [Evaluation criteria for viscosity change rate] ◎: Viscosity change rate is less than 3% ○: Viscosity change rate is 3% or more and less than 5% △: Viscosity change rate is 5% or more but less than 10% ×: Viscosity change rate is 10% or more

[0152] <1-2-3. Curability evaluation method> Spacers with the thickness of the test piece (1 mm) were placed on the four sides of the top surface of a glass plate (trade name "GLASS PLATE", manufactured by AS ONE Corporation, 200 mm x 200 mm x 5 mm thick), and a mold (20 mm x 20 mm) in the shape of the test piece was created. The prepared model material clear composition was poured into the mold, and then another glass plate of the same type was placed on top of it. Next, ultraviolet light was irradiated onto the top and bottom surfaces of the plate using a UV-LED with a central wavelength of 385 nm, with a predetermined cumulative light intensity, to cause curing. The cured product was then released from the glass plate to obtain test pieces (20 mm x 20 mm).

[0153] The obtained test piece was checked to see if it was cured with a predetermined integrated light amount. The measured curability was evaluated according to the following evaluation criteria.

[0154] [Curability evaluation criteria] ◎: Accumulated light intensity 5J / cm 2 It hardened with. 〇: Accumulated light output 7.5J / cm 2 It hardened with. △: Accumulated light intensity 15J / cm 2 It hardened with. ×: Accumulated light intensity 15J / cm 2 There are uncured areas [(2) Cured product of model material clear composition] (2-1. Preparation and Evaluation Method of Cured Product) The model material clear compositions of Examples 1 to 22 and Comparative Examples 1 to 4 were photocured to produce cured products, and the tensile strength, color, and total light transmittance of each cured product were evaluated. The methods for producing and evaluating the cured products are described below. The evaluation results are also shown in Tables 5 and 6.

[0155] <2-1-1. Tensile strength evaluation method> The clear model material compositions of Examples 1 to 22 and Comparative Examples 1 to 4 were each molded using an ultraviolet-curing inkjet molding device in accordance with the multipurpose test piece type A1 shape specified in JIS K 7139:2009 "Plastics - Test pieces." The tensile strength of these measurement samples was measured in accordance with JIS K7162:1994 "Plastics - Test methods for tensile properties, Part 2: Test conditions for molded, extruded, and cast plastics" (molding conditions: single layer thickness 32 μm, illuminance 1000 mW / cm). 2 , 1 layer integrated light intensity 800mJ / cm 2 ).

[0156] The measured tensile strength was evaluated according to the following evaluation criteria.

[0157] [Evaluation criteria] ○: A value of 30 MPa or more was shown. △: A value of 20 MPa or more and less than 30 MPa was shown. ×: A value of less than 20 MPa was shown.

[0158] <2-1-2. How to evaluate the color of the cured product> Test pieces were prepared from the model material clear compositions of Examples 1 to 22 and Comparative Examples 1 to 4 by the method described in paragraph

[0152] of the present specification. The Lab color difference of these samples was measured using a spectrophotometer "CM-5" (manufactured by Konica Minolta, Inc.).

[0159] L of the measured Lab color difference * value, a * value and b * The values ​​were evaluated according to the following criteria: * , a * and b * The values ​​represent the hue of the sample color, i.e., the color space coordinates of the color.

[0160] [L evaluation criteria] ○: The L value was 95 or higher. △: The L value was 90 or more and less than 95. ×: The L value was less than 90.

[0161] [a * Evaluation criteria 〇:a * The value was greater than or equal to -2 and less than 2. ×:a * The value was less than -2 and greater than or equal to 2.

[0162] [b * Evaluation criteria ◎:b * The value was greater than or equal to -2 and less than 1. 〇:b * The value of was greater than or equal to -5 and less than -2, or greater than or equal to 1 and less than 2. △:b * The value of was greater than or equal to -10 and less than -5, or greater than or equal to 2 and less than 4. ×:b * The value was less than -10 and greater than or equal to 4.

[0163] <2-1-3. Evaluation of total light transmittance> Test pieces were prepared from the model material clear compositions of Examples 1 to 22 and Comparative Examples 1 to 4 by the method described in paragraph

[0152] of the present specification. The total light transmittance of the samples was measured using a turbidity meter "NDH2000" (manufactured by Nippon Denshoku Industries Co., Ltd.).

[0164] The measured total light transmittance was evaluated according to the following evaluation criteria.

[0165] [Evaluation criteria for total light transmittance] ◯: Total light transmittance was 85 or more. △: Total light transmittance was 80 or more and less than 85. ×: Total light transmittance was less than 80.

[0166] <2-1-4. Evaluation of Crystal Tone> The obtained Lab color difference L * value, a * value and b * The crystal tone of the model material clear composition was evaluated based on the value and total light transmittance according to the following evaluation criteria.

[0167] [Crystal-like evaluation criteria] 〇:L * , a * , b * The evaluation of both the light transmittance and the total light transmittance was ⊚ or ◯. △:L * , a * , b * and total light transmittance were evaluated as △, but not as ×. ×:L * , a * , b * and total light transmittance were evaluated as x.

[0168] [(3) Experimental Results] The viscosity, storage stability, and curability of the model material clear compositions of Examples 1 to 22 and Comparative Examples 1 to 4, as well as the tensile strength, color, and total light transmittance of the cured products prepared by photocuring the model material clear compositions of Examples 1 to 22 and Comparative Examples 1 to 4, are shown in Tables 5 and 6. Comparative Example 2 was not completely cured, so some evaluations were not performed.

[0169] [Table 5]

[0170] [Table 6]

[0171] Referring to Tables 5 and 6, it was confirmed that the model material clear composition according to the present invention has storage stability and curing properties above a certain level, and that the cured product of the model material clear composition according to the present invention has tensile strength above a certain level, is less yellowish, and becomes a highly transparent, crystal-like clear model material.

[0172] [(4) Cured product of model material clear composition containing colorant] (4-1. Preparation of a cured product of a model material clear composition containing a coloring material) A coloring material (quinizarin blue) was added to the model material clear compositions of Example 2 and Comparative Example 1 in the proportions shown in Table 7 to prepare the compositions of Example 23 and Comparative Example 5.

[0173] (4-2. Evaluation method for cured products containing coloring materials) The model material clear compositions of Example 23 and Comparative Example 5 were cured using the same methods as in Examples 1 to 22 and Comparative Examples 1 to 4. The color, total light transmittance, and crystal tone of the cured products were then evaluated according to the same evaluation criteria as in Examples 1 to 22 and Comparative Examples 1 to 4. The evaluation results for the color and total light transmittance of the cured products are shown in Table 7. For comparison, the color and total light transmittance of the cured products prepared in Example 2 and Comparative Example 1 are also shown in Table 7.

[0174] [Table 7]

[0175] Referring to Table 7, by blending a coloring material as in Example 23, the cured product of the model material clear composition according to the present invention can be obtained as L * , a * and without compromising total light transmittance, b * It was confirmed that the above-mentioned characteristics could be improved, resulting in a clearer model material with a more excellent crystal appearance. * The colorant is blended into a composition with a large absolute value of b * Even if we improve * It was also confirmed that the total light transmittance was impaired and a crystal-like clear model material could not be obtained.

Claims

1. A clear model material composition for use in a material jet stereolithography method, comprising an ethylenically unsaturated compound (A), a photopolymerization initiator, a polymerization inhibitor, and an antioxidant, The ethylenically unsaturated compound (A) is an ethylenically unsaturated monomer (A1) having at least one group selected from the group consisting of a dicyclopentenyl group and a dicyclopentanyl group, the photopolymerization initiator is at least one photopolymerization initiator selected from the group consisting of acylphosphine oxide-based photopolymerization initiators and α-hydroxyacetophenone-based photopolymerization initiators, the polymerization inhibitor is a hindered amine-based polymerization inhibitor, the antioxidant is a phenolic antioxidant, The contents (mass%) of the initiator, polymerization inhibitor, and antioxidant are expressed by the following formulas (1) and (2): Photopolymerization initiator content ≧ polymerization inhibitor content ≧ antioxidant content (1) 1≦[√Photopolymerization initiator content / √{(polymerization inhibitor content×10) ２ + (antioxidant content x 100) ２ } × 100≦800 (2) Fulfilling the content of the photopolymerization initiator is 0.5 to 15% by mass, the content of the polymerization inhibitor is 0.01 to 5% by mass, The model material clear composition has an antioxidant content of 0.001 to 3 mass %.

2. 2. The model material clear composition according to claim 1, wherein the ethylenically unsaturated monomer (A1) is contained in an amount of 30% by mass or more based on the total mass of the ethylenically unsaturated compound (A).

3. The ethylenically unsaturated compound (A) is The model material clear composition according to claim 1 or 2, further comprising an ethylenically unsaturated compound (A2) having an aliphatic cyclic structure in the molecule and having a urethane group.

4. The model material clear composition according to claim 3, wherein the ethylenically unsaturated compound (A2) is contained in an amount of 10 mass % or more based on the total mass of the ethylenically unsaturated compound (A).

5. The ethylenically unsaturated compound (A) is The model material clear composition according to any one of claims 1 to 4, further comprising an ethylenically unsaturated monomer (A3) (excluding the ethylenically unsaturated monomer (A1) and the ethylenically unsaturated compound (A2)).

6. The model material clear composition according to any one of claims 1 to 5, wherein the photopolymerization initiator is at least one photopolymerization initiator selected from the group consisting of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide, and 1-hydroxy-cyclohexyl-phenyl-ketone.

7. The model material clear composition according to any one of claims 1 to 6, further comprising a surface conditioner.

8. The model material clear composition according to any one of claims 1 to 7, further comprising a colorant having an absorption wavelength in the range of 530 to 620 nm.

9. The model material clear composition according to any one of claims 1 to 8, wherein the viscosity of the model material clear composition stored for 30 days in an environment at 60°C changes by less than 10% compared to the viscosity of the model material clear composition before storage.

10. At a thickness of 2 mm, the L of the Lab color system ＊ The value is 90 or more, and a ＊ The value is equal to or greater than -2 and less than 2, and b ＊ The model material clear composition according to any one of claims 1 to 9, which provides a photocured product having a value of -10 or more and less than 4.

11. A photocured product obtained by photocuring the model material clear composition according to any one of claims 1 to 10.

12. A material jet stereolithography composition set comprising the model material clear composition according to any one of claims 1 to 10 and a model material color composition used in material jet stereolithography.

13. A material jet stereolithography composition set comprising the model material clear composition according to any one of claims 1 to 10 and a support material composition for forming a support material by material jet stereolithography.

14. The material jet stereolithography composition set according to claim 13, further comprising a model material color composition used in the material jet stereolithography method.

15. A stereolithography product obtained by photocuring the model material clear composition according to any one of claims 1 to 10 or the material jet stereolithography composition set according to any one of claims 12 to 14 by a material jet stereolithography method.

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