阅读说明：本技术 光造形用树脂组合物 (Resin composition for stereolithography ) 是由 伊东美咲 铃木宪司 于 2019-10-04 设计创作，主要内容包括：本发明提供在通过光造形进行造形时容易在低粘度下造形且能够获得韧性和耐水性优异的造形物、尤其是用于光造型成齿科用牙垫、义齿基托材料的光造形用树脂组合物。本发明涉及光造形用树脂组合物,其含有氨基甲酸酯化(甲基)丙烯酸类化合物(A)和光聚合引发剂(B),前述氨基甲酸酯化(甲基)丙烯酸类化合物(A)为1分子内含有多元醇部分和氨基甲酸酯键的(甲基)丙烯酸酯,所述多元醇部分为选自具有源自具有支链结构的碳原子数4～18的脂肪族链状二醇单元(a)的结构的聚酯、聚碳酸酯、聚氨酯和聚醚中的至少1种。(The invention provides a resin composition for optical modeling, which is easy to shape under low viscosity when optical modeling is carried out, and can obtain a shaped object with excellent toughness and water resistance, in particular to a resin composition for optical modeling used for optical modeling of dental pads and denture base materials. The present invention relates to a resin composition for stereolithography, which contains a urethane (meth) acrylic compound (A) and a photopolymerization initiator (B), wherein the urethane (meth) acrylic compound (A) is a (meth) acrylate containing a polyol moiety and a urethane bond in 1 molecule, and the polyol moiety is at least 1 selected from the group consisting of polyesters, polycarbonates, polyurethanes, and polyethers having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms.)

1. A resin composition for stereolithography, which comprises a urethane (meth) acrylic compound (A) and a photopolymerization initiator (B),

the urethane (meth) acrylic compound (A) is a (meth) acrylate containing a polyol moiety and a urethane bond in 1 molecule, and the polyol moiety is at least 1 selected from the group consisting of polyesters, polycarbonates, polyurethanes, and polyethers having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms.

2. The resin composition for stereolithography according to claim 1, wherein said urethane (meth) acrylic compound (A) is a (meth) acrylate containing in 1 molecule a polyol moiety of at least 1 selected from the group consisting of a polyester and a polycarbonate,

the polyester has a structure derived from an aliphatic chain dicarboxylic acid and/or aromatic dicarboxylic acid unit (b) having 4 to 18 carbon atoms and no branched structure, and the polycarbonate has a structure derived from an aliphatic chain diol unit (c) having 4 to 18 carbon atoms and no branched structure.

3. The resin composition for stereolithography according to claim 1 or 2, wherein the weight average molecular weight of the polyol moiety contained in said carbamated (meth) acrylic compound (A) is 400 to 10000.

4. The resin composition for stereolithography according to any one of claims 1 to 3, wherein the weight average molecular weight of said carbamated (meth) acrylic compound (A) is from 1000 to 20000.

5. The resin composition for stereolithography according to any one of claims 1 to 4, further comprising a (meth) acrylate compound (C) having a viscosity of 1000mPa, less than or equal to that of seeds and having an atmospheric boiling point of 280 ℃ or higher, and/or a (meth) acrylamide compound (D) having a viscosity of 1000mPa, less than or equal to that of seeds and having an atmospheric boiling point of 200 ℃ or higher.

6. The resin composition for stereolithography according to claim 5, wherein said (meth) acrylate compound (C) having a viscosity of 1000mPa & seeds or less and an atmospheric boiling point of 280 ℃ or higher and/or said (meth) acrylamide compound (D) having a viscosity of 1000mPa & seeds or less and an atmospheric boiling point of 200 ℃ or higher is monofunctional.

7. The resin composition for stereolithography according to claim 5 or 6, wherein the (meth) acrylate compound (C) having a viscosity of 1000mPa or less and an atmospheric boiling point of 280 ℃ or higher is an aliphatic (meth) acrylate having a hydrocarbon group having 11 to 18 carbon atoms.

8. The resin composition for stereolithography according to claim 7, wherein said aliphatic (meth) acrylate having a hydrocarbon group having 11 to 18 carbon atoms is at least 1 selected from the group consisting of lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, oleyl (meth) acrylate and isobornylcyclohexyl (meth) acrylate.

9. A dental bite block comprising a cured product of the resin composition for stereolithography according to any one of claims 1 to 8.

10. A denture base material comprising a cured product of the resin composition for stereolithography according to any one of claims 1 to 8.

11. A method for producing a stereolithographic object, comprising using the resin composition for stereolithography according to any one of claims 1 to 8, and producing a stereolithographic object by an optical stereolithography method.

Technical Field

The present invention relates to a resin composition for stereolithography. More specifically, in the present invention, when the molding is performed by the photo-molding (particularly, the suspended liquid tank photo-molding), the molding is easily performed at a low viscosity, and a molded product having excellent toughness and water resistance can be obtained. Is especially suitable for dental bite block (マウスピース) and denture base material.

Background

Patent document 1 discloses: a method of producing a three-dimensional object by repeating a step of supplying a liquid photocurable resin with light energy controlled to a necessary amount to cure the resin into a sheet-like form, further supplying a liquid photocurable resin thereon, and then irradiating the resin with light under control to laminate and cure the resin into a sheet-like form, which is a so-called optical three-dimensional molding method. Further, patent document 2 proposes a basic practical method thereof, and then proposes a plurality of proposals relating to an optical three-dimensional modeling technique.

As a typical method for optically producing a three-dimensional object, a method of producing a liquid tank containing a three-dimensional object in a final shape by repeating a laminating operation of: the liquid surface of the liquid photocurable resin composition contained in the container was selectively irradiated with an ultraviolet laser controlled by a computer so as to obtain a desired pattern, and cured to a predetermined thickness to form a cured layer, and then 1 layer of the liquid photocurable resin composition was supplied onto the cured layer, and the cured layer was similarly irradiated with an ultraviolet laser and cured in the same manner as described above to form a continuous cured layer. In this method, even if the shape of the shaped object is very complicated, the objective three-dimensional shaped object can be produced easily and accurately in a short time, and therefore attention has been paid in recent years. Further, a method of gradually lowering a shaped article in a container containing a large amount of liquid photocurable resin composition has been conventionally employed, but recently, a liquid photocurable resin composition can be completed in a small amount, and a hanging type with less loss has been becoming mainstream.

Further, a three-dimensional object obtained by the optical three-dimensional modeling method has been applied to applications such as a test model and a test product from a simple conceptual model, and accordingly, the three-dimensional object is required to have excellent modeling accuracy. In addition to such characteristics, excellent characteristics in accordance with the object are also required. In particular, in the field of dental materials, since the shape of dental pads and denture bases varies and is complicated depending on individual patients, application of the optical stereolithography method is expected.

Examples of dental pads include: a bite block called dental appliance to be worn in dentition (column ) for the purpose of correcting the arrangement of teeth; a bite block called an oral cavity appliance (OA) which is worn on the dentition at night for the treatment of sleep apnea syndrome; a bite block called a night guard (ナイトガード) which is worn on the dentition in order to suppress tooth abrasion due to bruxism; a bite block called a dental bite plate to be worn on the dentition for the treatment of the temporomandibular joint. This is a device which can be removed in recent years for dental correction because of high aesthetic quality and can be rapidly applied to a wide range of applications. In addition, sleep apnea syndrome is also a disorder of interest in medical treatment, and is rapidly being used as a treatment tool for the same.

The denture base material is a material used for a gum portion when a denture is installed due to loss of teeth. In recent years, the demand for dentures has sharply increased with the increase in the aging population.

Toughness and water resistance are required for both of these dental pads and denture base materials. If the toughness is impaired, the mounting feeling deteriorates, or an impact of external force or occlusion directly acts on the jawbone. Further, if the film is easily broken, it is necessary to do it again frequently. Further, if the water resistance is impaired, there are problems that the mechanical properties are lowered, the correction force and the impact absorbability are lost, or the composition is easily broken and is not durable.

In addition, in general, when manufacturing dental pads and denture base materials, it is necessary to obtain an impression in the oral cavity, but problems have been pointed out in the past that this is uncomfortable, which causes a burden on the patient and requires skill in the technician's operation. In recent years, with the development of digital technology, attempts have been made to apply optical intraoral scanning for impression acquisition, and attempts have been made to apply optical stereolithography for molding. In particular, in optical stereolithography, since the time for light irradiation is extremely short and the formation of one layer by one layer is exposed to oxygen, curing is particularly likely to be insufficient, and it has been difficult to achieve both of the mechanical strength and the flexibility and the water resistance. Further, although a viscosity capable of molding the resin composition is required, many monomers exhibiting mechanical strength have a high viscosity, and when a low-viscosity monomer is used to achieve a low viscosity, a large amount of low-boiling substances is generated, resulting in a problem that an odor is perceived. In particular, suspended stereolithography requires a lower viscosity because of a smaller amount of liquid.

Under such circumstances, as a technique for enabling optical stereolithography with excellent flexibility and mechanical strength of a cured product, for example, patent document 3 proposes a photocurable resin composition having excellent moldability, flexibility and mechanical strength, which comprises a specific urethane oligomer and an acrylamide compound having a chain structure, and patent document 4 proposes a photocurable resin composition having excellent curability and moisture resistance, which is composed of an acrylamide oligomer.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 56-144478

Patent document 2: japanese laid-open patent publication No. Sho 60-247515

Patent document 3: international publication No. 2018/038056

Patent document 4: international publication No. 2017/047615.

Disclosure of Invention

Problems to be solved by the invention

The photocurable resin composition described in patent document 3 is not specifically described with respect to water resistance, and patent document 4 is not specifically described with respect to formability in suspended optical stereolithography.

Accordingly, an object of the present invention is to provide a resin composition for stereolithography that can be easily molded at a low viscosity when it is molded by stereolithography (in particular, suspended-type liquid tank stereolithography), and that has a cured product having excellent toughness and water resistance. Further, it is an object of the present invention to provide a resin composition for stereolithography which is particularly suitable for dental pads and denture base materials.

Means for solving the problems

That is, the present invention relates to the following inventions.

[1] A resin composition for stereolithography, which comprises a urethane (meth) acrylic compound (A) and a photopolymerization initiator (B),

the urethane (meth) acrylic compound (A) is a (meth) acrylate containing 1 molecule of a polyol moiety and a urethane bond, wherein the polyol moiety is at least 1 selected from the group consisting of polyesters, polycarbonates, polyurethanes, and polyethers having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms;

[2] the resin composition for stereolithography according to [1], wherein the urethane (meth) acrylic compound (A) is a (meth) acrylate containing in 1 molecule a polyol moiety of at least 1 selected from the group consisting of a polyester having a structure derived from an aliphatic chain dicarboxylic acid having 4 to 18 carbon atoms and/or an aromatic dicarboxylic acid unit (b) having no branched structure and a polycarbonate having a structure derived from an aliphatic chain diol unit (c) having 4 to 18 carbon atoms and having no branched structure;

[3] the resin composition for stereolithography according to [1] or [2], wherein a weight average molecular weight of a polyol moiety contained in the carbamated (meth) acrylic compound (A) is 400 to 10000;

[4] the resin composition for stereolithography according to any one of [1] to [3], wherein the weight average molecular weight of the urethane-modified (meth) acrylic compound (A) is 1000 to 20000;

[5] the resin composition for stereolithography according to any one of [1] to [4], further comprising a (meth) acrylate compound (C) having a viscosity of 1000mPa or less and an atmospheric boiling point of 280 ℃ or more and/or a (meth) acrylamide compound (D) having a viscosity of 1000mPa or less and an atmospheric boiling point of 200 ℃ or more;

[6] the resin composition for stereolithography according to [5], wherein the (meth) acrylate compound (C) having a viscosity of 1000mPa or less and an atmospheric boiling point of 280 ℃ or higher and/or the (meth) acrylamide compound (D) having a viscosity of 1000mPa or less and an atmospheric boiling point of 200 ℃ or higher is monofunctional;

[7] the resin composition for stereolithography according to [5] or [6], wherein the (meth) acrylate compound (C) having a viscosity of 1000mPa or less and an atmospheric boiling point of 280 ℃ or higher is an aliphatic (meth) acrylate having a hydrocarbon group having 11 to 18 carbon atoms;

[8] the resin composition for stereolithography according to [7], wherein the aliphatic (meth) acrylate having a hydrocarbon group having 11 to 18 carbon atoms is at least 1 selected from the group consisting of lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, oleyl (meth) acrylate and isobornylcyclohexyl (meth) acrylate;

[9] a dental mouthpiece comprising a cured product of the resin composition for stereolithography according to any one of [1] to [8 ];

[10] a denture base material comprising a cured product of the resin composition for stereolithography according to any one of [1] to [8 ];

[11] a method for producing a stereolithographic object, wherein the stereolithographic resin composition according to any one of [1] to [8] is used to produce a stereolithographic object by an optical stereolithographic method.

Effects of the invention

The resin composition for stereolithography of the present invention can be used suitably for various dental materials, particularly dental pads and denture base materials, because it can be easily shaped at a low viscosity and the toughness and water resistance of the cured product are excellent when it is shaped by stereolithography (particularly, suspended-type liquid bath stereolithography).

Detailed Description

The resin composition for stereolithography of the present invention contains a urethane (meth) acrylic compound (A) and a photopolymerization initiator (B), wherein the urethane (meth) acrylic compound (A) is a (meth) acrylate containing a polyol moiety and a urethane bond in 1 molecule, and the polyol moiety is at least 1 selected from the group consisting of polyesters, polycarbonates, polyurethanes, and polyethers having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms. In the present specification, the upper limit and the lower limit of the numerical range (the content of each component, the numerical value calculated from each component, each physical property, and the like) may be appropriately combined. In the present specification, numerical values of respective symbols in the formulae may be appropriately combined.

[ carbamated (meth) acrylic Compound (A) ]

The urethane (meth) acrylic compound (a) is used to impart toughness and water resistance to a cured product of the resin composition for stereolithography because it imparts curability and achieves a low viscosity to the resin composition for stereolithography of the present invention.

The carbamated (meth) acrylic compound (A) is characterized by containing the polyol moiety and a urethane bond, and can be easily synthesized, for example, by subjecting a polyol having a structure derived from the aliphatic chain diol unit (a) having 4 to 18 carbon atoms and a branched structure, a compound having an isocyanate group (-NCO), and a (meth) acrylate having a hydroxyl group (-OH) to an addition reaction. The carbamated (meth) acrylic compound (A) may have a polyester polyol moiety having a structure derived from an aliphatic chain diol unit (a) having 4 to 18 carbon atoms and a branched structure and a polyol moiety other than the polyester polyol moiety (for example, a polyester polyol moiety having a structure derived from an aliphatic chain dicarboxylic acid and/or aromatic dicarboxylic acid unit (b) having 4 to 18 carbon atoms and no branched structure) coexisting in 1 molecule via a diisocyanate group. The carbamated (meth) acrylic compound (a) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

As described above, it is important: the urethane (meth) acrylic compound (A) contains a urethane bond and a polyol moiety selected from the group consisting of polyesters, polycarbonates, polyurethanes, and polyethers having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms. From the viewpoint of moldability, toughness, and water resistance, the carbamated (meth) acrylic compound (a) is preferably a compound containing 1 molecule of a structure derived from the aliphatic chain diol unit (a), and further containing (i) a structure derived from an aliphatic chain dicarboxylic acid having 4 to 18 carbon atoms and/or an aromatic dicarboxylic acid unit (b) having no branched structure, and/or (ii) a structure derived from an aliphatic chain diol unit having 4 to 18 carbon atoms and having no branched structure (c). From the viewpoint of moldability, toughness, and water resistance, the urethanized (meth) acrylic compound (a) is more preferably a (meth) acrylate further containing in 1 molecule at least 1 polyol moiety selected from the group consisting of a polyester having a structure derived from an aliphatic chain dicarboxylic acid having 4 to 18 carbon atoms and/or an aromatic dicarboxylic acid unit (b) having no branched structure and a polycarbonate having a structure derived from an aliphatic chain diol unit (c) having 4 to 18 carbon atoms and having no branched structure. The polyester includes a copolymer having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms and a structure derived from an aliphatic chain dicarboxylic acid and/or aromatic dicarboxylic acid unit (b) having no branched structure and having 4 to 18 carbon atoms. The polycarbonate is a polymer having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms and a structure derived from an aliphatic chain diol unit (c) having no branched structure and having 4 to 18 carbon atoms. The polyurethane includes a polycondensate of a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms and a diisocyanate compound. The polyether includes a polyether having a structure derived from an aliphatic chain diol unit (a) having a branched structure and having 4 to 18 carbon atoms. Among these, polyesters and polycarbonates are preferably contained as the polyol moiety from the viewpoint of excellent toughness and water resistance.

Examples of the aliphatic chain diol unit (a) having 4 to 18 carbon atoms and a branched structure include 2-methyl-1, 3-propanediol, 2-diethyl-1, 3-propanediol, 1, 3-butanediol, 2-methyl-1, 4-butanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 2-methyl-1, 8-octanediol, 2, 7-dimethyl-1, 8-octanediol, 2-methyl-1, 9-nonanediol, 2, 8-dimethyl-1, 9-nonanediol, 2-methyl-1, 10-decanediol, 2, 9-dimethyl-1, 10-decanediol, and 2-methyl-1, 11-undecanediol, 2, 10-dimethyl-1, 11-undecanediol, 2-methyl-1, 12-dodecanediol, 2, 11-dimethyl-1, 12-dodecanediol, 2-methyl-1, 13-tridecanediol, 2, 12-dimethyl-1, 13-tridecanediol, 2-methyl-1, 14-tetradecanediol, 2, 13-dimethyl-1, 14-tetradecanediol, 2-methyl-1, 15-pentadecanediol, 2, 14-dimethyl-1, 15-pentadecanediol, 2-methyl-1, 16-hexadecanediol, 2, 15-dimethyl-1, 16-hexadecanediol, etc. Among these, from the viewpoint of excellent curability and low viscosity of the resin composition for stereolithography, aliphatic diols having 5 to 12 carbon atoms and having a methyl group as a side chain, such as 2-methyl-1, 4-butanediol, 3-methyl-1, 5-pentanediol, 2-methyl-1, 8-octanediol, 2, 7-dimethyl-1, 8-octanediol, 2-methyl-1, 9-nonanediol, 2, 8-dimethyl-1, 9-nonanediol and the like, are preferably used as the polyol component, and more preferably 2-methyl-1, 4-butanediol, 3-methyl-1, 5-pentanediol, 2-methyl-1, 8-octanediol, 2, 7-dimethyl-1, 8-octanediol, more preferably 3-methyl-1, 5-pentanediol, 2-methyl-1, 8-octanediol.

Examples of the aliphatic chain dicarboxylic acid having 4 to 18 carbon atoms and/or the aromatic dicarboxylic acid unit (b) having no branched structure include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, undecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, phthalic acid, terephthalic acid, and isophthalic acid. Among these, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid are preferable, and adipic acid, sebacic acid, and isophthalic acid are more preferable, from the viewpoint of excellent curability of the resin composition for stereolithography and excellent water resistance of a cured product.

Examples of the aliphatic chain diol unit (c) having 4 to 18 carbon atoms and no branched structure include 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, 1, 11-undecanediol, 1, 12-dodecanediol, 1, 13-tridecanediol, 1, 14-tetradecanediol, 1, 15-pentadecanediol, 1, 16-hexadecanediol, 1, 17-heptadecanediol, and 1, 18-octadecanediol. Among these, from the viewpoint of excellent curability of the resin composition for stereolithography and excellent water resistance of the cured product, 1, 6-hexanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, 1, 11-undecanediol, and 1, 12-dodecanediol are preferable, 1, 6-hexanediol, 1, 8-octanediol, 1, 9-nonanediol, and 1, 10-decanediol are more preferable, and 1, 6-hexanediol and 1, 9-nonanediol are even more preferable.

The weight average molecular weight (Mw) of the polyol moiety contained in the carbamated (meth) acrylic compound (A) is preferably 400 to 10000, more preferably 400 to 7500, still more preferably 600 to 5000, and particularly preferably 800 to 3000, from the viewpoints of viscosity and strength. The weight average molecular weight (Mw) in the present invention is a weight average molecular weight in terms of polystyrene determined by Gel Permeation Chromatography (GPC).

Examples of the compound having an isocyanate group include Hexamethylene Diisocyanate (HDI), Toluene Diisocyanate (TDI), Xylylene Diisocyanate (XDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMHMDI), tricyclodecane diisocyanate (TCDDI), and Adamantane Diisocyanate (ADI).

Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycerol mono (meth) acrylate, N-hydroxyethyl (meth) acrylamide, N-bis (2-hydroxyethyl) (meth) acrylamide, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, 2-bis [4- (3- (meth) acryloyloxy-2-hydroxypropoxy) phenyl ] propane, and mixtures thereof, And hydroxy (meth) acrylate compounds such as 1, 2-bis (3- (meth) acryloyloxy-2-hydroxypropoxy) ethane, pentaerythritol tri (meth) acrylate, dipentaerythritol tri-or tetra (meth) acrylate, and the like.

The addition reaction of the compound having an isocyanate group and the (meth) acrylate having a hydroxyl group can be carried out by a known method, and is not particularly limited.

The obtained urethane (meth) acrylic compound (a) includes a reaction product of at least 1 kind of polyol selected from the group consisting of the aforementioned polyesters, polycarbonates, polyurethanes, and polyethers, and any combination of a compound having an isocyanate group and a (meth) acrylate having a hydroxyl group.

From the viewpoint of viscosity and toughness, the weight average molecular weight (Mw) of the carbamated (meth) acrylic compound (a) is preferably 1000 to 20000, more preferably 1250 to 15000, and further preferably 1500 to 10000.

The content of the carbamated (meth) acrylic compound (a) in the resin composition for stereolithography according to the present invention is preferably 10 to 99% by mass based on the total amount of the carbamated (meth) acrylic compound (a), (meth) acrylate compound (C) having a viscosity of 1000mPa · s or less and an atmospheric boiling point of 280 ℃ or higher and (meth) acrylamide compound (D) having a viscosity of 1000mPa · s or less and an atmospheric boiling point of 200 ℃ or higher, and more preferably 30 to 95% by mass, and even more preferably 50 to 90% by mass, from the viewpoint of further excellent moldability, toughness and water resistance of the cured product. In the present specification, "normal pressure" means atmospheric pressure.

[ photopolymerization initiator (B) ]

The photopolymerization initiator (B) used in the present invention can be selected from photopolymerization initiators generally used in the industry and used, and among them, photopolymerization initiators used in dental applications are preferable.

Examples of the photopolymerization initiator (B) include (di) acylphosphine oxides, quaternary ammonium salts of thioxanthones or thioxanthones, ketals, α -diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, α -amino ketone compounds, and the like. The photopolymerization initiator (B) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Among these photopolymerization initiators (B), at least 1 selected from (di) acylphosphine oxides and α -diketones is preferably used. Thus, a resin composition for stereolithography which has excellent photocurability in the ultraviolet region and the visible light region and exhibits sufficient photocurability even when any light source of a laser, a halogen lamp, a light-emitting diode (LED), and a xenon lamp is used can be obtained.

Among (bis) acylphosphine oxides, examples of acylphosphine oxides include 2,4, 6-trimethylbenzoyldiphenylphosphine oxide, 2, 6-dimethoxybenzoyldiphenylphosphine oxide, 2, 6-dichlorobenzoyldiphenylphosphine oxide, 2,4, 6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4, 6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5, 6-tetramethylbenzoyldiphenylphosphine oxide, benzoylbis (2, 6-dimethylphenyl) phosphonate, 2,4, 6-trimethylbenzoylphenylphosphine oxide sodium salt, 2,4, 6-trimethylbenzoylphenylphosphine oxide potassium salt, and 2,4, 6-trimethylbenzoyldiphenylphosphine oxide ammonium salt. Examples of bisacylphosphine oxides include bis (2, 6-dichlorobenzoyl) phenylphosphine oxide, bis (2, 6-dichlorobenzoyl) -2, 5-dimethylphenylphosphine oxide, bis (2, 6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis (2, 6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis (2, 6-dimethoxybenzoyl) phenylphosphine oxide, bis (2, 6-dimethoxybenzoyl) -2,4, 4-trimethylpentylphosphine oxide, bis (2, 6-dimethoxybenzoyl) -2, 5-dimethylphenylphosphine oxide, bis (2,4, 6-trimethylbenzoyl) phenylphosphine oxide, bis (2,5, 6-trimethylbenzoyl) -2,4, 4-trimethylpentylphosphine oxide, and the like. Further, compounds described in Japanese patent laid-open No. 2000-159621 may be mentioned.

Among these (bis) acylphosphine oxides, 2,4, 6-trimethylbenzoyldiphenylphosphine oxide, 2,4, 6-trimethylbenzoylmethoxyphenylphosphine oxide, bis (2,4, 6-trimethylbenzoyl) phenylphosphine oxide and 2,4, 6-trimethylbenzoylphenylphosphine oxide sodium salt are particularly preferably used as the photopolymerization initiator (B).

Examples of the α -diketones include butanedione, benzil, camphorquinone, 2, 3-pentanedione, 2, 3-octanedione, 9, 10-phenanthrenequinone, 4' -oxybenzol, and acenaphthenequinone. Among them, camphorquinone is particularly preferable when a light source in the visible light region is used.

The content of the photopolymerization initiator (B) in the resin composition for stereolithography of the present invention is not particularly limited as long as the effects of the present invention are exhibited, and is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total amount of the polymerizable compounds from the viewpoint of curability of the obtained resin composition for stereolithography. When the content of the photopolymerization initiator (B) is less than 0.01 part by mass, polymerization may not sufficiently proceed, and a stereogenic object may not be obtained. The content of the photopolymerization initiator (B) is more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the total amount. On the other hand, if the content of the photopolymerization initiator (B) exceeds 20 parts by mass, precipitation from the resin composition for stereolithography may occur if the solubility of the photopolymerization initiator itself is low. The content of the photopolymerization initiator (B) is more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less, and particularly preferably 5.0 parts by mass or less, relative to 100 parts by mass of the total amount.

The resin composition for stereolithography of the present invention preferably further contains a (meth) acrylate compound (C) having a viscosity of 1000mPa, seeds or less and an atmospheric boiling point of 280 ℃ or higher, and/or a (meth) acrylamide compound (D) having a viscosity of 1000mPa, seeds or less and an atmospheric boiling point of 200 ℃ or higher. The (meth) acrylate compound (C) having a viscosity of 1000mPa, seeds or less and an atmospheric boiling point of 280 ℃ or more and/or the (meth) acrylamide compound (D) having a viscosity of 1000mPa, seeds or less and an atmospheric boiling point of 200 ℃ or more are more preferably monofunctional. The viscosity in the present invention means a viscosity measured at 25 ℃ by a Brookfield rotational viscometer. The measurement conditions such as time and revolution are appropriately adjusted according to the predicted measurement viscosity range. As the Brookfield rotational viscometer, a commercially available one (for example, B-type rotational viscometer (model: BL) manufactured by トキメック) can be used. The atmospheric boiling point in the present invention is a measured value obtained by atmospheric distillation, and for a compound whose atmospheric boiling point cannot be observed, an atmospheric boiling point obtained by converting a reduced-pressure boiling point, which is a measured value in reduced-pressure distillation, into a boiling point conversion table (Science of Petroleum, vol.ii. p.1281(1938)) is used.

[ the (meth) acrylate Compound (C) having a viscosity of 1000mPa or less and an atmospheric boiling point of 280 ℃ or more ]

The (meth) acrylate compound (C) having a viscosity of 1000mPa or less and an atmospheric boiling point of 280 ℃ or more (hereinafter sometimes simply referred to as the "(meth) acrylate compound (C)") is used in the resin composition for stereolithography of the present invention for the purpose of reducing the viscosity of the resin composition for stereolithography and imparting water resistance to a cured product. When the atmospheric boiling point is 280 ℃ or higher, unpleasant odor is hardly felt from the resin composition for stereolithography of the present invention. The atmospheric boiling point of the (meth) acrylate compound (C) is preferably 300 ℃ or higher, more preferably 320 ℃ or higher. The viscosity of the (meth) acrylate compound (C) is preferably 500mPa or less, more preferably 200mPa or less. The (meth) acrylate compound (C) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the (meth) acrylate compound (C) in the present invention include a monofunctional (meth) acrylate compound having 1 (meth) acryloyl group and a polyfunctional (meth) acrylate compound having a plurality of (meth) acryloyl groups. Among these, monofunctional (meth) acrylate compounds are preferable from the viewpoint of excellent flexibility of the resulting cured product. In addition, from the viewpoint of water resistance, among the monofunctional (meth) acrylate compounds, an aliphatic (meth) acrylate having a hydrocarbon group having 3 to 18 carbon atoms is preferable, and an aliphatic (meth) acrylate having a hydrocarbon group having 11 to 18 carbon atoms is more preferable. The hydrocarbon group may be linear or branched. Examples of the hydrocarbon group include an alkyl group and an alkenyl group, and an alkyl group is preferable. The number of carbon atoms of the hydrocarbon group is more preferably 12 to 16. The hydrocarbon group may have a substituent or may be unsubstituted. Examples of the substituent include an amino group, a hydroxyl group, an oxo group, an alkoxy group (e.g., having 1 to 6 carbon atoms), an amide group, an acyl group (e.g., having 1 to 6 carbon atoms), an acyloxy group (e.g., having 1 to 6 carbon atoms), a cyano group, a nitro group, and the like, and a hydroxyl group is preferable. The (meth) acrylate compound (C) preferably does not contain a urethane bond.

Examples of the monofunctional (meth) acrylate compound include undecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, palmityl (meth) acrylate, heptadecyl (meth) acrylate, oleyl (meth) acrylate, monofunctional aliphatic (meth) acrylates such as stearyl (meth) acrylate, isostearyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, glycerol mono (meth) acrylate, erythritol mono (meth) acrylate, and isobornylcyclohexyl (meth) acrylate; o-phenylphenol (meth) acrylate, m-phenylphenol (meth) acrylate, p-phenylphenol (meth) acrylate, methoxylated o-phenylphenol (meth) acrylate, methoxylated m-phenylphenol (meth) acrylate, methoxylated p-phenylphenol (meth) acrylate, ethoxylated o-phenylphenol (meth) acrylate, ethoxylated m-phenylphenol (meth) acrylate, ethoxylated-p-phenylphenol (meth) acrylate, propoxylated o-phenylphenol (meth) acrylate, propoxylated m-phenylphenol (meth) acrylate, propoxylated p-phenylphenol (meth) acrylate, butoxylated o-phenylphenol (meth) acrylate, butoxylated m-phenylphenol (meth) acrylate, butoxylated p-phenylphenol (meth) acrylate, a mixture thereof, and a mixture thereof, O-phenoxybenzyl (meth) acrylate, m-phenoxybenzyl (meth) acrylate, p-phenoxybenzyl (meth) acrylate, 2- (o-phenoxyphenyl) ethyl (meth) acrylate, 2- (m-phenoxyphenyl) ethyl (meth) acrylate, 2- (p-phenoxyphenyl) ethyl (meth) acrylate, 3- (o-phenoxyphenyl) propyl (meth) acrylate, 3- (m-phenoxyphenyl) propyl (meth) acrylate, 3- (p-phenoxyphenyl) propyl (meth) acrylate, 4- (o-phenoxyphenyl) butyl (meth) acrylate, 4- (m-phenoxyphenyl) butyl (meth) acrylate, 4- (p-phenoxyphenyl) butyl (meth) acrylate, 5- (o-phenoxyphenyl) pentyl (meth) acrylate, p-phenoxyphenyl) butyl (meth) acrylate, p-phenoxyphenyl) butyl (, Monofunctional aromatic (meth) acrylates such as 5- (m-phenoxyphenyl) pentyl (meth) acrylate, 5- (p-phenoxyphenyl) pentyl (meth) acrylate, 6- (o-phenoxyphenyl) hexyl (meth) acrylate, 6- (m-phenoxyphenyl) hexyl (meth) acrylate, and 6- (p-phenoxyphenyl) hexyl (meth) acrylate. These can be used alone in 1 kind, also can be combined with more than 2 kinds. Among these, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, oleyl (meth) acrylate, m-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate, isobornylcyclohexyl (meth) acrylate are preferable, lauryl (meth) acrylate, cetyl (meth) acrylate, isobornylcyclohexyl (meth) acrylate are more preferable, lauryl (meth) acrylate, isobornylcyclohexyl (meth) acrylate are still more preferable, and isobornylcyclohexyl (meth) acrylate is most preferable, from the viewpoint of excellent curability of the resin composition for stereolithography and toughness and water resistance of a cured product.

Examples of the polyfunctional (meth) acrylate compound include aromatic compound-based bifunctional (meth) acrylate compounds, aliphatic compound-based bifunctional (meth) acrylate compounds, and trifunctional or higher (meth) acrylate compounds.

Examples of the aromatic compound-based bifunctional (meth) acrylate compound include 2, 2-bis (4- (meth) acryloyloxyethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxypolyethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxytetraethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxypentaethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxydipropyloxyphenyl) propane, 2- (4- (meth) acryloyloxydiethoxyphenyl) -2- (4- (meth) acryloyloxyethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 2- (4- (meth) acryloyloxyethoxyphenyl) propane, 2- (meth) acryloyloxyethoxyphenyl) propane, and mixtures thereof, 2- (4- (meth) acryloyloxydiethoxyphenyl) -2- (4- (meth) acryloyloxytriethoxyphenyl) propane, 2- (4- (meth) acryloyloxydiproxyphenyl) -2- (4- (meth) acryloyloxytriethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxypropoxyphenyl) propane, 2-bis (4- (meth) acryloyloxyisopropoxyphenyl) propane, 1, 4-bis (2- (meth) acryloyloxyethyl) pyromellitate and the like.

Examples of the aliphatic compound-based difunctional (meth) acrylate compound include glycerol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1, 3-butylene glycol di (meth) acrylate, 1, 4-butylene glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 2-ethyl-1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, and mixtures thereof, 1, 2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethane, and the like.

Examples of the trifunctional or higher (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolmethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and the like.

The content of the (meth) acrylate compound (C) in the resin composition for stereolithography of the present invention is preferably 1.0 to 80% by mass relative to the total amount of the (meth) acrylate compound (a), (meth) acrylate compound (C) and the (meth) acrylamide compound (D) having a viscosity of 1000mPa, a seeding rate or less and an atmospheric boiling point of 200 ℃ or higher, and is more preferably 5 to 70% by mass, and still more preferably 10 to 60% by mass, from the viewpoint of further excellent moldability, toughness of a cured product, and water resistance.

[ Compound (D) of (meth) acrylamide having a viscosity of 1000mPa or less and an atmospheric boiling point of 200 ℃ or higher ]

The (meth) acrylamide compound (D) having a viscosity of 1000mPa or less, a seed or seed and an atmospheric boiling point of 200 ℃ or more (hereinafter sometimes simply referred to as "(meth) acrylamide compound (D)") is used in the resin composition for stereolithography of the present invention for the purpose of imparting curability to the resin composition for stereolithography, while achieving a low viscosity. The atmospheric boiling point of the (meth) acrylamide compound (D) is preferably 225 ℃ or higher, more preferably 250 ℃ or higher. When the boiling point at atmospheric pressure is 250 ℃ or higher, unpleasant odor is hardly felt from the resin composition for stereolithography of the present invention. The viscosity of the (meth) acrylamide compound (D) is preferably 500mPa or less, more preferably 200mPa or less. The (meth) acrylamide compound (D) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the (meth) acrylamide compound (D) in the present invention include N, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, N-di-N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-tert-octyl acrylamide, N-di-N-butyl (meth) acrylamide, N-di-N-hexyl (meth) acrylamide, N-di-N-octyl (meth) acrylamide, N-di-2-ethylhexyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N-bis (2-hydroxyethyl) (meth) acrylamide, N-di-N-octyl (meth) acrylamide, N-di-2-ethylhexyl (meth) acrylamide, N-di-N-butyl (meth) acrylamide, N-di-N-propyl (meth) acrylamide, N-tert, N-acryloylmorpholine, N-dimethylaminoethyl (meth) acrylamide, N-diethylaminoethyl (meth) acrylamide, N-dipropylaminoethyl (meth) acrylamide, N-dibutylaminoethyl (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide, N-diethylaminopropyl (meth) acrylamide, n, N-dipropylaminopropyl (meth) acrylamide, N-dibutylaminopropyl (meth) acrylamide, N-dimethylaminobutyl (meth) acrylamide, N-diethylaminobutyl (meth) acrylamide, N-dipropylaminobutyl (meth) acrylamide, N-dibutylaminobutyl (meth) acrylamide. These can be used alone in 1 kind, also can be combined with more than 2 kinds. Among these, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, N-acryloylmorpholine, N-dimethylaminoethyl (meth) acrylamide, N-diethylaminoethyl (meth) acrylamide, and N, N-diethylaminoethyl (meth) acrylamide are more preferable, and N, N-diethyl (meth) acrylamide and N-acryloylmorpholine are even more preferable, from the viewpoint of excellent viscosity and curability of the resin composition for stereolithography and excellent water resistance of a cured product.

The content of the (meth) acrylamide compound (D) in the resin composition for stereolithography according to the present invention is preferably 1 to 60% by mass, more preferably 2.5 to 40% by mass, and still more preferably 5 to 20% by mass, based on the total amount of the carbamated (meth) acrylic compound (a), (meth) acrylate compound (C), and (meth) acrylamide compound (D).

The resin composition for stereolithography according to the present invention may contain a polymerizable compound other than the carbamated (meth) acrylic compound (a), and the polymerizable compound may be substantially composed of only the carbamated (meth) acrylic compound (a), may be substantially composed of only the carbamated (meth) acrylic compound (a) and the (meth) acrylate compound (C), or may be substantially composed of only the carbamated (meth) acrylic compound (a), (meth) acrylate compound (C), and the (meth) acrylamide compound (D). The polymerizable compound is substantially composed of only the carbamated (meth) acrylic compound (a), the (meth) acrylate compound (C), and the (meth) acrylamide compound (D), and means that: the content of the other polymerizable compounds other than the carbamated (meth) acrylic compound (a), (meth) acrylate compound (C), and (meth) acrylamide compound (D) is less than 10.0% by mass, preferably less than 5.0% by mass, more preferably less than 1.0% by mass, still more preferably less than 0.1% by mass, and particularly preferably less than 0.01% by mass, relative to the total amount of the polymerizable compounds contained in the resin composition for stereolithography.

The resin composition for stereolithography of the present invention is not particularly limited as long as it contains the urethane (meth) acrylic compound (a) and the photopolymerization initiator (B), and may contain other components, for example. The resin composition for stereolithography of the present invention can be produced by a known method.

The resin composition for stereolithography of the present invention may contain a polymerization accelerator (E) for the purpose of enhancing photocurability within a range not to impair the gist of the present invention. Examples of the polymerization accelerator (E) include ethyl 4- (N, N-dimethylamino) benzoate, methyl 4- (N, N-dimethylamino) benzoate, N-butoxyethyl 4- (N, N-dimethylamino) benzoate, 2- (methacryloyloxy) ethyl 4- (N, N-dimethylamino) benzoate, 4- (N, N-dimethylamino) benzophenone, and butyl 4- (N, N-dimethylamino) benzoate. The polymerization accelerator (E) may be used alone in 1 kind, or may be used in combination in 2 or more kinds. Among these, from the viewpoint of imparting excellent curability to the resin composition for stereolithography, it is preferable to use at least 1 selected from the group consisting of ethyl 4- (N, N-dimethylamino) benzoate, N-butoxyethyl 4- (N, N-dimethylamino) benzoate, and 4- (N, N-dimethylamino) benzophenone.

The resin composition for stereolithography of the present invention may further contain a filler (F) in order to adjust the paste properties or modify the surface properties or strength of the cured product of the resin composition for stereolithography. Examples of the filler (F) include an organic filler, an inorganic filler, and an organic-inorganic composite filler. The filler (F) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the material of the organic filler include polymethyl methacrylate, polyethyl methacrylate, a methyl methacrylate-ethyl methacrylate copolymer, crosslinked polymethyl methacrylate, crosslinked polyethyl methacrylate, polyester, polyamide, polycarbonate, polyphenylene ether, polyoxymethylene, polyvinyl chloride, polystyrene, polyethylene, polypropylene, chloroprene rubber, nitrile rubber, an ethylene-vinyl acetate copolymer, a styrene-butadiene copolymer, an acrylonitrile-styrene copolymer, and an acrylonitrile-styrene-butadiene copolymer. These can be used alone in 1 kind, also can be combined with more than 2 kinds. The shape of the organic filler is not particularly limited, and the particle diameter of the filler can be appropriately selected and used.

Examples of the material of the inorganic filler include quartz, silica, alumina, silica-titania-barium oxide, silica-zirconia, silica-alumina, lanthanum glass, borosilicate glass, soda glass, barium glass, strontium glass, glass ceramic, aluminosilicate glass, barium boroaluminosilicate glass, strontium boroaluminosilicate glass, fluoroaluminosilicate glass, calcium fluoroaluminosilicate glass, strontium fluoroaluminosilicate glass, barium fluoroaluminosilicate glass, and strontium calcium fluoroaluminosilicate glass. Further, they may be used alone in 1 kind, or in combination of 2 or more kinds. The shape of the inorganic filler is not particularly limited, and an irregularly shaped filler, a spherical filler, or the like can be appropriately selected and used.

The resin composition for stereolithography of the present invention may contain a polymer for the purpose of modifying flexibility, flowability, etc., within a range not to impair the gist of the present invention. For example, natural rubber, synthetic polyisoprene rubber, liquid polyisoprene rubber and its hydride, polybutadiene rubber, liquid polybutadiene rubber and its hydride, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, isoprene-isobutylene rubber, acrylonitrile-butadiene rubber or styrene-based elastomer may be added. Specific examples of the other polymer that can be added include a polystyrene-polyisoprene-polystyrene block copolymer, a polystyrene-polybutadiene-polystyrene block copolymer, a poly (α -methylstyrene) -polybutadiene-poly (α -methylstyrene) block copolymer, a poly (p-methylstyrene) -polybutadiene-poly (p-methylstyrene) block copolymer, and hydrogenated products thereof.

The resin composition for stereolithography of the present invention may contain a softening agent as needed. Examples of the softening agent include petroleum-based softening agents such as paraffin-based, naphthene-based, and aromatic-based process oils; and vegetable oil softeners such as paraffin, peanut oil, and rosin. These softening agents may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The content of the softening agent is not particularly limited as long as the gist of the present invention is not impaired, and is usually 200 parts by mass or less, preferably 100 parts by mass or less, based on 100 parts by mass of the total amount of the carbamated (meth) acrylic compound (a), (meth) acrylate compound (C), and (meth) acrylamide compound (D).

The resin composition for stereolithography of the present invention may contain a chemical polymerization initiator for the purpose of improving curability within a range not to impair the gist of the present invention. Organic peroxides and azo compounds are preferably used. The organic peroxide and azo compound used as the chemical polymerization initiator are not particularly limited, and known ones can be used. Typical examples of the organic peroxide include ketone peroxides, hydrogen peroxide, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates.

In the resin composition for stereolithography of the present invention, a known stabilizer may be added for the purpose of suppressing deterioration or adjusting photocurability. Examples of the stabilizer include a polymerization inhibitor, an ultraviolet absorber, and an antioxidant.

Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutylhydroquinone monomethyl ether, 4-t-butylcatechol, 2-t-butyl-4, 6-dimethylphenol, 2, 6-di-t-butylphenol, and 3, 5-di-t-butyl-4-hydroxytoluene. The content of the polymerization inhibitor is preferably 0.001 to 1.0 part by mass with respect to 100 parts by mass of the total amount of the carbamated (meth) acrylic compound (a), (meth) acrylic acid ester compound (C), and (meth) acrylamide compound (D).

In addition, the resin composition for stereolithography of the present invention may contain known additives for the purpose of adjusting the color tone or adjusting the paste properties. Examples of the additive include pigments, dyes, organic solvents, and thickeners.

The resin composition for stereolithography of the present invention can be easily molded at a low viscosity when it is molded by stereolithography (in particular, suspended-type liquid tank stereolithography), and can give a molded article having excellent toughness and water resistance. Therefore, the resin composition for stereolithography and the cured product thereof of the present invention can be applied to applications (for example, oral applications) that exhibit such advantages, and are particularly suitable for dental treatments such as dental pads (oral appliances (OA), night guards, dental bite plates) and denture base materials. Further, the resin composition for stereolithography of the present invention can be suitably used as a protective tool against external force for sports use, in addition to dental treatment uses such as dental pads and denture base materials, and as a tooth protector (マウスガード). The resin composition for thermoforming of the present invention is more likely to have excellent effects such as toughness, water resistance, and formability, and therefore is preferably used as a resin composition for thermoforming of a suspended liquid tank. The shape of the cured product of the resin composition for stereolithography according to the present invention can be changed depending on the application. The resin composition for stereolithography of the present invention can be prepared by adjusting the type and content of each component (the carbamated (meth) acrylic compound (a), the photopolymerization initiator (B), the (meth) acrylate compound (C), the (meth) acrylamide compound (D), and various optional components (the polymerization accelerator (E), the filler (F), the polymer, the softener, the stabilizer, the additive, and the like)) as needed and according to the use of the dental pad, the denture base material, and the like.

The resin composition for stereolithography of the present invention can be used in various applications by taking advantage of its properties, particularly the ability to obtain a stereolithography product having a small volume shrinkage rate and excellent modeling accuracy when cured with light, and the properties of other cured products, and can be used for, for example, production of a stereolithography product by an optical stereolithography method, production of various stereolithography products such as a film or a mold by a casting method or a casting method, covering applications, and a mold for vacuum forming.

Among these, the resin composition for stereolithography of the present invention is suitable for use in the above-mentioned optical stereolithography method, and in this case, a stereolithography excellent in toughness and water resistance can be produced smoothly while keeping the volume shrinkage rate during photocuring low.

In another embodiment of the present invention, there is provided a method for producing a three-dimensional object by an optical three-dimensional molding method using any of the aforementioned resin compositions for stereolithography.

When the resin composition for stereolithography of the present invention is used for optical stereolithography (in particular, suspended-type liquid-bath stereolithography), conventionally known suspended optical stereolithography methods and apparatuses (for example, stereolithography machines such as digitawax (registered trademark) 020D, manufactured by DWS) can be used. Among them, in the present invention, as the light energy for curing the resin, an active energy ray is preferably used. The "active energy ray" refers to an energy ray capable of curing the resin composition for stereolithography, such as ultraviolet ray, electron ray, X-ray, radiation, high frequency, and the like. For example, the activation energy ray may be ultraviolet ray having a wavelength of 300 to 420 nm. Examples of the light source of the activation energy ray include a laser such as an Ar laser and a He — Cd laser; and a halogen lamp, a xenon lamp, a metal halide lamp, an LED, a mercury lamp, a fluorescent lamp, and the like, and particularly preferably a laser. When a laser is used as the light source, the energy level can be increased to shorten the shaping time, and a three-dimensional shaped object with high shaping precision can be obtained by utilizing the good light condensing property of the laser beam.

As described above, when the resin composition for stereolithography of the present invention is used for optical stereolithography, any conventionally known method or conventionally known stereolithography system apparatus can be used, and there are no particular limitations thereon, and as a typical example of the optical stereolithography method preferably used in the present invention, a method of obtaining a desired stereolithography product by repeating the following steps: a step of selectively irradiating the resin composition for stereolithography with active energy rays so as to obtain a cured layer having a desired pattern, thereby forming a cured layer; and then, a step of suspending the cured layer, supplying the uncured liquid resin composition for stereolithography, and irradiating the uncured liquid resin composition with active energy rays in the same manner to form a new cured layer continuous with the cured layer and laminating the cured layer. The stereolithographic object thus obtained may be used as it is, or may be further subjected to post-curing by light irradiation or heat, to thereby obtain a product having further improved mechanical properties, shape stability, and the like.

The flexural modulus of the cured product of the resin composition for stereolithography of the present invention is preferably in the range of 0.3 to 3.0GPa, more preferably in the range of 0.5 to 2.5GPa, and still more preferably in the range of 0.8 to 2.0 GPa. When the flexural modulus of the cured product is 2.0GPa or less, the following effects can be obtained: exhibits soft properties, and is excellent in the wearing feeling because of good followability to teeth when formed into a bite block, and is less likely to fall off by bruxism or the like during sleep at night. The bending strength of the cured product of the resin composition for stereolithography of the present invention is preferably 30MPa or more, more preferably 40MPa or more, and still more preferably 50MPa or more.

The structure, shape, size, and the like of the three-dimensional object obtained by the optical three-dimensional shaping method are not particularly limited, and can be determined according to various applications. As a representative application field of the optical stereolithography method of the present invention, a model for verifying an appearance design in a design process can be cited; a model for checking the functionality of the component; a resin mold for making a mold; a base model for making a mold; and (4) making a direct model for trial molding. More specifically, there can be mentioned the production of a mold or a processing mold for precision parts, electric/electronic parts, furniture, building structures, automobile parts, various containers, castings, molds, and molds.

Examples

The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples at all, and those having ordinary knowledge in the art can make various modifications within the scope of the technical idea of the present invention.

< Synthesis example 1> [ production of a carbamated (meth) acrylic Compound (A-1) ]

(1) 250g of isophorone diisocyanate and 0.15g of di-n-butyltin dilaurate were added to a 5L four-necked flask having an internal volume equipped with a stirrer, a temperature controller, a thermometer, and a condenser, and heated to 70 ℃ with stirring.

(2) On the other hand, 1000g of polycarbonate polyol ("クラレポリオール (registered trademark) C-1090", manufactured by クラレ corporation, polyol consisting of 1, 6-hexanediol/3-methyl-1, 5-pentanediol (mass ratio): 9/1, and having a weight average molecular weight Mw of 1000) was added to a dropping funnel with a side tube, and the liquid in the dropping funnel was dropped into the flask of the above (1). The solution in the flask of the above (1) was stirred and simultaneously dropped at a constant rate for 4 hours while maintaining the internal temperature of the flask at 65 to 75 ℃. After the completion of the dropwise addition, the mixture was stirred at the same temperature for 2 hours to react.

(3) Subsequently, a liquid in which 150g of 2-hydroxyethyl acrylate and 0.4g of hydroquinone monomethyl ether were uniformly dissolved and added to a separate dropping funnel was added dropwise at a constant rate over 2 hours while keeping the internal temperature of the flask at 55 to 65 ℃, and then the reaction was carried out for 4 hours while keeping the temperature of the solution in the flask at 70 to 80 ℃, thereby obtaining a carbamated (meth) acrylic compound (a-1). The weight average molecular weight Mw of the carbamated (meth) acrylic compound (A-1) analyzed by GPC was 1700.

< Synthesis example 2> [ production of carbamated (meth) acrylic Compound (A-2) ]

(1) 250g of isophorone diisocyanate and 0.15g of di-n-butyltin dilaurate were added to a 5L four-necked flask having an internal volume equipped with a stirrer, a temperature controller, a thermometer, and a condenser, and heated to 70 ℃ with stirring.

(2) On the other hand, 2500g of a polyester polyol ("クラレポリオール (registered trademark) P-2050" manufactured by クラレ Co., Ltd.; a polyol comprising sebacic acid and 3-methyl-1, 5-pentanediol and having a weight-average molecular weight Mw of 2000) was charged into a dropping funnel with a side tube, and the liquid in the dropping funnel was dropped into the flask described in (1) above. The solution in the flask of the above (1) was stirred and simultaneously dropped at a constant rate for 4 hours while maintaining the internal temperature of the flask at 65 to 75 ℃. After the completion of the dropwise addition, the mixture was stirred at the same temperature for 2 hours to react.

(3) Subsequently, a liquid in which 150g of 2-hydroxyethyl acrylate and 0.4g of hydroquinone monomethyl ether were uniformly dissolved and added to a separate dropping funnel was added dropwise at a constant rate over 2 hours while keeping the internal temperature of the flask at 55 to 65 ℃, and then the reaction was carried out for 4 hours while keeping the temperature of the solution in the flask at 70 to 80 ℃, thereby obtaining a carbamated (meth) acrylic compound (a-2). The weight average molecular weight Mw of the carbamated (meth) acrylic compound (A-2) analyzed by GPC was 2600.

< Synthesis example 3> [ production of a carbamated (meth) acrylic Compound (A-3) ]

(1) 250g of isophorone diisocyanate and 0.15g of di-n-butyltin dilaurate were added to a 5L four-necked flask having an internal volume equipped with a stirrer, a temperature controller, a thermometer, and a condenser, and heated to 70 ℃ with stirring.

(2) On the other hand, 520g of polyester polyol ("クラレポリオール (registered trademark) P-530" manufactured by クラレ Co., Ltd.; polyol comprising isophthalic acid and 3-methylpentanediol and having a weight-average molecular weight Mw of 500) was charged into a dropping funnel with a side tube, and the liquid in the dropping funnel was dropped into the flask described in (1) above. The solution in the flask of the above (1) was stirred and simultaneously dropped at a constant rate for 4 hours while maintaining the internal temperature of the flask at 65 to 75 ℃. After the completion of the dropwise addition, the mixture was stirred at the same temperature for 2 hours to react.

(3) Subsequently, a liquid in which 150g of 2-hydroxyethyl acrylate and 0.4g of hydroquinone monomethyl ether were uniformly dissolved and added to a separate dropping funnel was added dropwise at a constant rate over 2 hours while keeping the internal temperature of the flask at 55 to 65 ℃, and then the reaction was carried out for 4 hours while keeping the temperature of the solution in the flask at 70 to 80 ℃, thereby obtaining a carbamated (meth) acrylic compound (a-3). The weight average molecular weight Mw of the carbamated (meth) acrylic compound (A-3) analyzed by GPC was 1100.

< Synthesis example 4> [ production of a carbamated (meth) acrylic Compound (1) ]

(1) 250g of isophorone diisocyanate and 0.15g of di-n-butyltin dilaurate were added to a 5L four-necked flask having an internal volume equipped with a stirrer, a temperature controller, a thermometer, and a condenser, and heated to 70 ℃ with stirring.

(2) On the other hand, 1000g of polycarbonate polyol ("ニッポラン 981" manufactured by Tosoh Corp.; polyol comprising 1, 6-hexanediol and having a weight average molecular weight Mw of 1000) was charged into a dropping funnel with a side tube, and the liquid in the dropping funnel was dropped into the flask described in (1). The solution in the flask of the above (1) was stirred and simultaneously dropped at a constant rate for 4 hours while maintaining the internal temperature of the flask at 65 to 75 ℃. After the completion of the dropwise addition, the mixture was stirred at the same temperature for 2 hours to react.

(3) Subsequently, a liquid in which 150g of 2-hydroxyethyl acrylate and 0.4g of hydroquinone monomethyl ether were uniformly dissolved and added to a separate dropping funnel was added dropwise at a constant rate over 2 hours while keeping the internal temperature of the flask at 55 to 65 ℃, and then the reaction was carried out for 4 hours while keeping the temperature of the solution in the flask at 70 to 80 ℃, thereby obtaining a carbamated (meth) acrylic compound (1). The weight average molecular weight Mw of the carbamated (meth) acrylic compound (1) analyzed by GPC was 1700.

< Synthesis example 5> [ production of a carbamated (meth) acrylic Compound (2) ]

(1) 250g of isophorone diisocyanate and 0.15g of di-n-butyltin dilaurate were added to a 5L four-necked flask having an internal volume equipped with a stirrer, a temperature controller, a thermometer, and a condenser, and heated to 70 ℃ with stirring.

(2) On the other hand, 2500g of a polyester polyol ("HS 2H-200S" manufactured by Fengkou oil Co., Ltd.; a polyol comprising sebacic acid and 1, 6-hexanediol and having a weight-average molecular weight Mw of 2000) was charged into a dropping funnel with a side tube, and the liquid in the dropping funnel was dropped into the flask described in (1) above. The solution in the flask of the above (1) was stirred and simultaneously dropped at a constant rate for 4 hours while maintaining the internal temperature of the flask at 65 to 75 ℃. After the completion of the dropwise addition, the mixture was stirred at the same temperature for 2 hours to react.

(3) Subsequently, a liquid in which 150g of 2-hydroxyethyl acrylate and 0.4g of hydroquinone monomethyl ether were uniformly dissolved and added to a separate dropping funnel was added dropwise at a constant rate over 2 hours while keeping the internal temperature of the flask at 55 to 65 ℃, and then the reaction was carried out for 4 hours while keeping the temperature of the solution in the flask at 70 to 80 ℃, thereby obtaining a carbamated (meth) acrylic compound (2). The weight average molecular weight Mw of the carbamated (meth) acrylic compound (2) analyzed by GPC was 2600.

The components used in the resin compositions of examples and comparative examples are explained below together with their abbreviations.

[ photopolymerization initiator (B) ]

TPO: 2,4, 6-trimethylbenzoyldiphenylphosphine oxide

BAPO: bis (2,4, 6-trimethylbenzoyl) phenylphosphine oxide.

[ the (meth) acrylate Compound (C) having a viscosity of 1000mPa or less and an atmospheric boiling point of 280 ℃ or more ]

LMA: lauryl methacrylate (manufactured by Kyoeisha chemical Co., Ltd.) (viscosity of 4mPa, seeds and atmospheric pressure converted boiling point of 305 ℃ C.)

CMA: cetyl methacrylate (manufactured by Rizhi corporation) (viscosity 10mPa, atmospheric pressure converted boiling point 390 ℃ C.)

IBCHMA: 3-isobornyl cyclohexyl methacrylate (manufactured by Designer polymers Inc.) (viscosity 80mPa for seeds and seeds, and boiling point at atmospheric pressure conversion 380 ℃ C.).

[ Compound (D) of (meth) acrylamide having a viscosity of 1000mPa or less and an atmospheric boiling point of 200 ℃ or higher ]

ACMO: n-acryloyl morpholine (manufactured by KJ ケミカルズ Co.) (viscosity 12mPa, normal pressure converted boiling point 255 ℃)

DEAA: n, N-diethylacrylamide (manufactured by KJ ケミカルズ Co.) (viscosity: 1.7mPa seeds, atmospheric reduced boiling point: 220 ℃ C.).

[ polymerization inhibitor ]

BHT: 3, 5-di-tert-butyl-4-hydroxytoluene.

Examples 1 to 9 and comparative examples 1 to 3

The respective components were mixed at room temperature (20 ℃ C. + -. 15 ℃ C., JIS (Japanese Industrial Standard) Z8703: 1983) in the amounts shown in tables 1 and 2 to prepare pastes as resin compositions for stereolithography of examples 1 to 9 and comparative examples 1 to 3.

< formability >

The resin compositions for stereolithography of the examples and comparative examples were molded into test pieces 3.3mm in thickness, 10.0mm in width and 64mm in length using a stereolithography machine (digitarwax (registered trademark) 020D manufactured by DWS corporation) (n is 5). The case where the sheet having the same size can be formed is described as "O" which can be formed, and the case where the formed article cannot be formed at one time is described as "X" which cannot be formed. The molded test piece was used to perform each evaluation described later.

< toughness (flexural modulus, flexural Strength, fracture Point Displacement) >

With respect to the cured products of the resin compositions for stereolithography of each example and each comparative example, the resin composition was prepared in accordance with the acrylic resin for denture base JIS T6501: 2012, test pieces (length 39.0mm, width 4.0mm, thickness (height) 8.0mm, notch depth 3.0mm and angle 45 °) were produced and evaluated by bending strength test. According to JIS T6501: 2012, a bending strength test was carried out using a universal testing machine (オートグラフ AG-I100 kN manufactured by shimadzu corporation) at a crosshead speed of 5mm/min (n is 5). The average values of the measurement values of the respective test pieces were calculated as the bending strength and the bending elastic modulus. The bending modulus of the test piece is preferably in the range of 0.3 to 3.0GPa, more preferably in the range of 0.5 to 2.5GPa, and still more preferably in the range of 0.8 to 2.0 GPa. The bending strength is preferably 30MPa or more, more preferably 40MPa or more, and still more preferably 50MPa or more. It is preferable that the displacement of the breaking point is not broken, and the case where no breaking occurred until the end or breaking occurred when the displacement was 20mm or more is regarded as "good flexibility", the case where breaking occurred when the displacement exceeded 10mm and was less than 20mm is regarded as "medium flexibility", and the case where breaking occurred when the displacement was 10mm or less is regarded as "poor flexibility".

< Water resistance >

The cured products of the resin compositions for stereolithography of examples and comparative examples were immersed in water at 37 ℃ for 24 hours, and then the flexural strength (n: 5) was measured in the same manner as in the flexural strength test. The water resistance is excellent if the change rate (reduction rate) of the flexural strength after immersion in water at 37 ℃ for 24 hours from the initial flexural strength is 10% or less, taking the measurement result of the flexural strength among the above-mentioned toughness as the initial flexural strength.

A rate of change (reduction rate) of the bending strength (%) ({ initial bending strength (MPa) } bending strength (MPa) after 24 hours of immersion in water at 37 ℃.) × 100.

< odor >

With respect to the resin compositions for stereolithography of each example and each comparative example, 10 panelists were evaluated for off-flavor (n ═ 1). Among 10 panelists, those who felt unpleasant odor were rated as "o" when they were less than 2, rated as "Δ" when they felt unpleasant odor was more than 2 and less than 5, and rated as "x" when they felt unpleasant odor was more than 5. There is no particular problem as long as no unpleasant odor is felt.

As shown in tables 1 and 2, the resin compositions for stereolithography in examples 1 to 9 were excellent in moldability and had little odor. Further, the cured product thereof is excellent in toughness and water resistance. In particular, the toughness and water resistance of the cured products of the resin compositions for stereolithography of examples 1 to 9 were superior to those of the cured products of the resin compositions of comparative examples 1 and 3. The resin compositions for stereolithography of examples 1 to 9 were superior in moldability to the resin composition of comparative example 2. The resin composition for stereolithography of comparative example 2 failed to form a test piece and failed to measure the properties.

Industrial applicability

The resin composition for stereolithography of the present invention can be easily shaped at a low viscosity when shaped by stereolithography, and can give a shaped article excellent in toughness and water resistance, and therefore, the cured product thereof is particularly suitable for dental pads and denture base materials.