JP7426274B2 - Resin composition for stereolithography - Google Patents

Description

The present invention relates to a resin composition for stereolithography. More specifically, when the present invention is formed by stereolithography, it is possible to obtain a three-dimensional structure having excellent stress retention properties, toughness, and water resistance. It is particularly suitable for dental mouthpieces.

A necessary amount of controlled light energy is supplied to the liquid photocurable resin to cure it into a thin layer, and after further supplying the liquid photocurable resin on top of that, the liquid photocurable resin is irradiated with light in a controlled manner to form a thin layer. Many proposals have been made regarding a method of manufacturing a three-dimensional object by repeating the process of laminating and curing, a so-called optical three-dimensional modeling method.

A typical method for optically manufacturing three-dimensional objects is to apply a computer-controlled ultraviolet laser to the liquid surface of a liquid photocurable resin composition placed in a container so as to obtain a desired pattern. Selectively irradiate and cure to a predetermined thickness to form a cured layer, then supply one layer of liquid photocurable resin composition on top of the cured layer, and similarly irradiate with ultraviolet laser. Generally, a method called liquid bath stereolithography is employed, in which a three-dimensional object in the final shape is manufactured by repeating the lamination operation of curing and forming a continuous hardened layer in the same manner as described above. This method has attracted a lot of attention in recent years because even if the shape of the object is quite complex, it is possible to easily and accurately manufacture a three-dimensional object in a relatively short period of time.

Three-dimensional objects obtained by stereolithography are now being used for purposes such as test models and prototypes, rather than mere concept models. This is becoming increasingly required. Moreover, in addition to such characteristics, there is a demand for excellent characteristics that are tailored to the purpose. In particular, in the field of dental materials, the application of stereolithography is expected because dental mouthpieces have different shapes for each individual patient and have complex shapes.

Dental mouthpieces include dental aligners, which are worn on the teeth to correct the alignment of teeth, dental occlusal splints, which are worn to correct jaw position, and dental mouthpieces, which are used to treat sleep apnea syndrome. It is attached to the teeth at night while sleeping, and it is attached to the teeth to suppress tooth wear caused by bruxism, and it is used to prevent trauma caused by large external forces being applied to the teeth and jawbone during competitions in contact sports. These devices are worn inside the oral cavity to reduce the risk of injury and protect the stomatognathic system and brain. In recent years, the use of this device has rapidly expanded in orthodontics due to its good aesthetics and the fact that it can be removed when desired. In addition, sleep apnea syndrome is a case that is attracting attention in medical care, and its use as a treatment tool is rapidly progressing.

These dental mouthpieces are commonly required to have stress retention properties, toughness, and water resistance. If the stress retention ability is impaired, the corrective power and shock absorption properties will be lost, and the device will no longer function as a fitting. If the toughness is impaired, it will not feel comfortable to wear, and if it is easy to break, it will have to be remade frequently. The problem is that this becomes necessary. Furthermore, if the water resistance is impaired, the mechanical properties will deteriorate, resulting in a loss of straightening power and shock absorbing properties, and the problem of being easily broken and impractical.

In addition, when manufacturing dental mouthpieces and treatment devices for sleep apnea syndrome, it is usually necessary to take an impression of the oral cavity, but this can be a burden to the patient due to discomfort, and the technical Problems have been pointed out in the past, such as the need for skill in 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 three-dimensional modeling for molding. Photocurable resin compositions are used in modeling, but in general, resin compositions that exhibit stress retention and water resistance tend to use monomers with lower polarity, resulting in lower curability and less stress in the cured product. Especially in optical three-dimensional modeling, the light irradiation time is extremely short and each layer is exposed to oxygen, so curing tends to be insufficient. It was difficult to achieve both toughness and water resistance.

Against this background, for example, Patent Document 1 proposes a photocurable resin composition made of polybutadiene having a polymerizable group as a technology that has excellent toughness and water resistance of a cured product and enables optical three-dimensional modeling. has been done.

JP 2019-1939 Publication

The photocurable resin composition described in Patent Document 1 has insufficient strength as a dental aligner, a dental occlusal splint, and a treatment device for sleep apnea syndrome, and there is no mention of stress retention. do not have.

Therefore, an object of the present invention is to provide a resin composition for stereolithography that is suitable for dental mouthpieces, which has excellent stress retention properties, toughness, and water resistance as a cured product, and which is particularly molded by optical stereolithography. .

（式中、Ｒ¹は水素原子又はメチル基であり、Ｒ²は炭素数２～４のアルキレン基であり、ａは１又は２であり、Ａ¹は共役ジエン化合物の重合体及び／又はその水素添加物である。）
で表される末端（メタ）アクリロイル変性共役ジエン重合体（ａ－Ｉ）、及び下記一般式（ＩＩ）

（式中、Ｒ³は水素原子又はメチル基であり、Ｒ⁴、Ｒ⁵はそれぞれ独立に、２価の非置換又は置換された炭化水素基であり、Ｒ⁶は炭素数２～４のアルキレン基であり、ｂは１又は２であり、Ａ²は共役ジエン化合物の重合体及び／又はその水素添加物である。）
で表される末端（メタ）アクリロイル変性共役ジエン重合体（ａ－ＩＩ）からなる群から選ばれる少なくとも１種を含有する、光造形用樹脂組成物；
［２］Ｒ²及び／又はＲ⁶がエチレン基である、［１］に記載の光造形用樹脂組成物；
［３］Ｒ⁴及びＲ⁵の炭化水素基が、脂肪族、芳香族及び／又は脂環式の炭素数６～２０の炭化水素基である、［１］又は［２］に記載の光造形用樹脂組成物；
［４］前記末端（メタ）アクリロイル変性共役ジエン重合体（Ａ）が、一般式（ＩＩ）で表される末端（メタ）アクリロイル変性共役ジエン重合体（ａ－ＩＩ）を含有する、［１］～［３］のいずれかに記載の光造形用樹脂組成物；
［５］Ｒ⁵の炭化水素基が、イソホロン基、トリレン基、４，４’－ジフェニルメタン基、ナフチレン基、キシリレン基、フェニレン基、３，３’－ジクロロ－４，４’－フェニルメタン基、トルイレン基、ヘキサメチレン基、４，４’－ジシクロヘキシルメタン基、水添化キシリレン基、トリフェニレンメタン基、及びテトラメチルキシレン基からなる群から選ばれる少なくとも１種である、［１］～［４］のいずれかに記載の光造形用樹脂組成物；
［６］Ａ¹及びＡ²の共役ジエン化合物の重合体及び／又はその水素添加物が、ブタジエンの重合体、イソプレンの重合体、及びそれらの水素添加物からなる群から選ばれる少なくとも１種を含有する、［１］～［５］のいずれかに記載の光造形用樹脂組成物；
［７］末端（メタ）アクリロイル変性共役ジエン重合体及び／又はその水素添加物の数平均分子量が５００～１０，０００である、［１］～［６］のいずれかに記載の光造形用樹脂組成物；
［８］Ｒ¹及び／又はＲ³が水素原子である、［１］～［７］のいずれかに記載の光造形用樹脂組成物；
［９］前記重合体骨格を含有しない脂環式多官能性（メタ）アクリル酸エステル系重合性単量体（Ｃ）が、ヒドロキシ基、カルボキシ基、スルホン酸基、スルフィン酸基、リン酸基、１級及び２級のアミノ基、並びにウレタン結合を含有しないことを特徴とする、［１］～［８］に記載の光造形用樹脂組成物；
［１０］前記重合体骨格を含有しない脂環式多官能性（メタ）アクリル酸エステル系重合性単量体（Ｃ）が、多脂環式多官能性（メタ）アクリル酸エステル系重合性単量体を含む、［１］～［９］のいずれかに記載の光造形用樹脂組成物；
［１１］前記多脂環式多官能性（メタ）アクリル酸エステル系重合性単量体が、トリシクロデカン環、ノルボルナン環、アダマンタン環、及びデカヒドロナフタレン環からなる群から選ばれる少なくとも１つを含む、［１０］に記載の光造形用樹脂組成物；
［１２］前記重合体骨格を含有しない脂環式多官能性（メタ）アクリル酸エステル系重合性単量体（Ｃ）が、シクロペンタン環、シクロヘキサン環、及びシクロオクタン環からなる群から選ばれる少なくとも１つを含む、［１］～［９］のいずれかに記載の光造形用樹脂組成物；
［１３］前記（メタ）アクリルアミド化合物（Ｂ）が、単官能性（メタ）アクリルアミド化合物を含む、［１］～［１２］のいずれかに記載の光造形用樹脂組成物；
［１４］前記（メタ）アクリルアミド化合物（Ｂ）が、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリルアミド、Ｎ，Ｎ－ジエチルアミノエチル（メタ）アクリルアミド、Ｎ，Ｎ－ジメチルアミノプロピル（メタ）アクリルアミド、及びＮ，Ｎ－ジエチルアミノプロピル（メタ）アクリルアミドからなる群から選ばれる少なくとも１つを含む、［１］～［１３］のいずれかに記載の光造形用樹脂組成物；
［１５］［１］～［１４］のいずれかに記載の光造形用樹脂組成物の硬化物からなる、歯科材料；
［１６］［１］～［１４］のいずれかに記載の光造形用樹脂組成物の硬化物からなる、歯科用アライナー；
［１７］［１］～［１４］のいずれかに記載の光造形用樹脂組成物の硬化物からなる、歯科用咬合スプリント；
［１８］［１］～［１４］のいずれかに記載の光造形用樹脂組成物の硬化物からなる、睡眠時無呼吸症候群用治療具；
［１９］［１］～［１４］のいずれかに記載の光造形用樹脂組成物を用いて、光学的立体造形法によって立体造形物を製造する方法。 That is, the present invention provides the following inventions.
[1] Terminal (meth)acryloyl-modified conjugated diene polymer (A), (meth)acrylamide compound (B), alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer that does not contain a polymer skeleton (C) and a photopolymerization initiator (D),
The terminal (meth)acryloyl-modified conjugated diene polymer (A) has the following general formula (I)

(In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 2 to 4 carbon atoms, a is 1 or 2, and A ¹ is a polymer of a conjugated diene compound and/or its It is a hydrogen additive.)
A terminal (meth)acryloyl-modified conjugated diene polymer (a-I) represented by the following general formula (II)

(In the formula, R ³ is a hydrogen atom or a methyl group, R ⁴ and R ⁵ are each independently a divalent unsubstituted or substituted hydrocarbon group, and R ⁶ is an alkylene group having 2 to 4 carbon atoms. (b is 1 or 2, and A ² is a polymer of a conjugated diene compound and/or a hydrogenated product thereof.)
A stereolithography resin composition containing at least one member selected from the group consisting of (meth)acryloyl-terminated conjugated diene polymers (a-II) represented by;
[2] The stereolithography resin composition according to [1], wherein R ² and/or R ⁶ are ethylene groups;
[3] The stereolithography according to [1] or [2], wherein the hydrocarbon groups of R ⁴ and R ⁵ are aliphatic, aromatic and/or alicyclic hydrocarbon groups having 6 to 20 carbon atoms. Resin composition for;
[4] The terminal (meth)acryloyl-modified conjugated diene polymer (A) contains a terminal (meth)acryloyl-modified conjugated diene polymer (a-II) represented by general formula (II), [1] - The resin composition for stereolithography according to any one of [3];
[5] The hydrocarbon group of R ⁵ is an isophorone group, a tolylene group, a 4,4'-diphenylmethane group, a naphthylene group, a xylylene group, a phenylene group, a 3,3'-dichloro-4,4'-phenylmethane group, At least one member selected from the group consisting of toluylene group, hexamethylene group, 4,4'-dicyclohexylmethane group, hydrogenated xylylene group, triphenylenemethane group, and tetramethylxylene group, [1] to [4] The resin composition for stereolithography according to any one of;
[6] The polymer of the conjugated diene compound and/or the hydrogenated product of A ¹ and A ² is at least one selected from the group consisting of a butadiene polymer, an isoprene polymer, and a hydrogenated product thereof. The stereolithography resin composition according to any one of [1] to [5], which contains;
[7] The resin composition for stereolithography according to any one of [1] to [6], wherein the terminal (meth)acryloyl-modified conjugated diene polymer and/or its hydrogenated product has a number average molecular weight of 500 to 10,000. ;
[8] The resin composition for stereolithography according to any one of [1] to [7], wherein R ¹ and/or R ³ are hydrogen atoms;
[9] The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton contains a hydroxy group, a carboxy group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group The resin composition for stereolithography according to [1] to [8], characterized in that it does not contain a primary or secondary amino group, or a urethane bond;
[10] The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) containing no polymer skeleton is a polyalicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton. The stereolithography resin composition according to any one of [1] to [9], which contains a polymer;
[11] The polyalicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer is at least one selected from the group consisting of a tricyclodecane ring, a norbornane ring, an adamantane ring, and a decahydronaphthalene ring. The stereolithography resin composition according to [10], comprising;
[12] The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton is selected from the group consisting of a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring. The stereolithography resin composition according to any one of [1] to [9], containing at least one;
[13] The resin composition for stereolithography according to any one of [1] to [12], wherein the (meth)acrylamide compound (B) contains a monofunctional (meth)acrylamide compound;
[14] The (meth)acrylamide compound (B) is N,N-diethyl (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N - The resin composition for stereolithography according to any one of [1] to [13], which contains at least one selected from the group consisting of dimethylaminopropyl (meth)acrylamide and N,N-diethylaminopropyl (meth)acrylamide. thing;
[15] A dental material comprising a cured product of the stereolithography resin composition according to any one of [1] to [14];
[16] A dental aligner comprising a cured product of the stereolithography resin composition according to any one of [1] to [14];
[17] A dental occlusal splint, comprising a cured product of the stereolithography resin composition according to any one of [1] to [14];
[18] A therapeutic device for sleep apnea syndrome, comprising a cured product of the stereolithography resin composition according to any one of [1] to [14];
[19] A method of producing a three-dimensional object by optical three-dimensional modeling using the resin composition for stereolithography according to any one of [1] to [14].

The stereolithography resin composition of the present invention has excellent stress retention properties, toughness, and water resistance as a cured product, and is particularly suitable for dental mouthpieces molded by optical stereolithography.

The stereolithography resin composition of the present invention comprises a (meth)acryloyl-terminated conjugated diene polymer (A), a (meth)acrylamide compound (B), and an alicyclic polyfunctional (meth)acrylic acid that does not contain a polymer skeleton. Contains an acid ester polymerizable monomer (C) and a photopolymerization initiator (D). The terminal (meth)acryloyl-modified conjugated diene polymer (A) contains at least one selected from the group consisting of (meth)acryloyl-terminated conjugated diene polymers (a-I) and (a-II). In this specification, the upper and lower limits of numerical ranges (content of each component, value calculated from each component, each physical property, etc.) can be combined as appropriate. Furthermore, in this specification, the numerical values of each symbol in the formula can also be combined as appropriate.

[Terminal (meth)acryloyl-modified conjugated diene polymer (A)]
The (meth)acryloyl-terminated conjugated diene polymer (A) is used in the stereolithography resin composition of the present invention to impart flexibility and water resistance to the cured product of the stereolithography resin composition. Furthermore, the (meth)acryloyl-terminated conjugated diene polymer (A) has excellent modeling accuracy when cured with light. The (meth)acryloyl-terminated conjugated diene polymer (A) is considered to have excellent water resistance because the conjugated diene polymer skeleton has extremely low polarity and is hydrophobic.

As the terminal (meth)acryloyl-modified conjugated diene polymer (A), the terminal (meth)acryloyl-modified conjugated diene polymer (a-I) represented by the above general formula (I) (hereinafter referred to as "terminated (meth) acryloyl-modified conjugated diene polymer (a-I)"), and the terminal (meth)acryloyl-modified conjugated diene polymer (a-II) represented by the above general formula (II) (hereinafter referred to as "terminal (a-II)"). (referred to as "meth)acryloyl-modified conjugated diene polymer (a-II)") will be explained.

[Terminal (meth)acryloyl-modified conjugated diene polymer (a-I)]
Each symbol in formula (I) will be explained. R ¹ is a hydrogen atom or a methyl group, preferably a hydrogen atom. R ² is an alkylene group having 2 to 4 carbon atoms, and examples thereof include ethylene group, 1,3-propylene group, 1,2-propylene group, 1,4-butylene group, and 2-methyl-1,3-propylene group. and 1,1-dimethylethylene group, with ethylene group being preferred. a is 1 or 2, preferably 2.

Further, in formula (I), the group A ¹ is a polymer of a conjugated diene compound and/or a hydrogenated product thereof. Examples of conjugated diene compounds include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, farnesene, and the like. The group A ¹ is preferably composed of butadiene and/or its hydrogenated product; isoprene and/or its hydrogenated product; butadiene and isoprene and/or its hydrogenated product.

Regarding the polymer of the conjugated diene compound of group ^A1 , the microstructure of the conjugated diene polymer is not particularly limited, but when the conjugated diene is butadiene, the content of 1,2-bond units is 1 to 99 mol. %, more preferably 2.5 to 95 mol%. In addition, when the conjugated diene compound is isoprene or a mixture of butadiene and isoprene, the total content of 1,2-bond units and 3,4-bond units is 1 to 99 mol%. It is preferably 2.5 to 95 mol%, more preferably 2.5 to 95 mol%.

In addition, when the group A ¹ contains two or more types of conjugated dienes (for example, butadiene and isoprene), the bonding form thereof is not particularly limited, and may be random, tapered, completely alternating, partially block-like, or block-like. or a combination of two or more thereof.

The hydrogenated product of group A ¹ is usually introduced by preparing a conjugated diene polymer and hydrogenating it. The (meth)acryloyl-terminated conjugated diene polymer (A) in which the conjugated diene polymer is hydrogenated has a higher molecular weight than the (meth)acryloyl-terminated conjugated diene polymer (A) in which the conjugated diene polymer is not hydrogenated. High storage stability. Therefore, when the terminal (meth)acryloyl-modified conjugated diene polymer (A) contains a hydrogenated substance in the conjugated diene polymer, the hydrogenation rate is preferably 50 mol% or more, and 90 mol% or more. It is more preferable that there be.

Note that the hydrogenation rate of the hydrogenated product of group A ¹ can be determined by iodine value measurement, infrared spectroscopy measurement, NMR measurement, etc.

The group A ¹ may contain other monomer units in addition to the conjugated diene polymer, as long as the objects and effects of the present invention are not hindered. Other monomers include, for example, styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene, vinyl Structural units derived from naphthalene, vinylanthracene, methyl methacrylate, vinyl methyl ether, N-vinylcarbazole, β-pinene, 8,9-p-menthene, dipentene, methylenenorbornene, 2-methylenetetrahydrofuran, etc. are mentioned. The group A ¹ may contain one type of these monomers alone, or may contain two or more types of these monomers.

The number average molecular weight of the group A ¹ is preferably in the range of 500 to 10,000, more preferably in the range of 750 to 5,000, and even more preferably in the range of 1,000 to 3,000. preferable. When the number average molecular weight of the group A ¹ is 500 or more, the cured product of the stereolithography resin composition tends to have high toughness, and when it is 10,000 or less, the stereolithography resin composition has a suitable They tend to have liquidity. In addition, the number average molecular weight here means the number average molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC) measurement.

The molecular weight distribution (weight average molecular weight/number average molecular weight: Mw/Mn) of the group A ¹ of the present invention is 1.0 to 2.0 because it is easy to obtain an appropriate viscosity of the composition and high toughness of the cured product. It is preferably from 1.0 to 1.5, even more preferably from 1.0 to 1.25. The group A ¹ having such a molecular weight distribution can be obtained by a living anionic polymerization method. The weight average molecular weight can be measured by the GPC method similarly to the number average molecular weight.

The method for producing the (meth)acryloyl-terminated conjugated diene polymer (a-I) is not particularly limited, and regardless of the production method, the compound represented by the above general formula (I) and the light containing the compound can be used. Although the resin composition for modeling is included within the scope of the present invention, the terminal (meth)acryloyl-modified conjugated diene polymer (a-I) can be preferably produced by the following method.

（式中、Ｒ²、Ａ¹、及びａは上記と同一意味を有する。）
で表される末端水酸基変性共役ジエン重合体を得る。 <Typical manufacturing method example of terminal (meth)acryloyl-modified conjugated diene polymer (a-I)>
(1) After polymerizing a conjugated diene compound using a dianionic initiator such as 1,4-dilithio-1,1,4,4-tetraphenylbutane in a tetrahydrofuran solvent, ethylene oxide is added to convert it to terminal lithium oxide. Then, methanol was added to completely stop the reaction, and the following general formula (V) was obtained.

(In the formula, R ² , A ¹ , and a have the same meanings as above.)
A terminal hydroxyl group-modified conjugated diene polymer is obtained.

（式中、Ｒ¹、Ｒ²、Ａ¹、及びａは上記と同一意味を有する。）
で表される末端（メタ）アクリロイル変性共役ジエン重合体（ａ－Ｉ）を製造する。 (2) A terminal (meth)acryloyl-modified conjugated diene polymer (A) in which a polymer of a conjugated diene compound corresponding to the skeleton of A ¹ is hydrogenated, that is, a terminal containing a hydrogenated product of a conjugated diene polymer ( To produce the meth)acryloyl-modified conjugated diene polymer (A), the terminal hydroxyl group-modified conjugated diene polymer obtained by the method (1) above is heated with hydrogen in a saturated hydrocarbon solvent such as cyclohexane. Hydrogenation may be carried out in the presence of an added catalyst, usually at a reaction temperature of 20 to 100°C and a hydrogen pressure of 0.1 to 10 MPa. Examples of the hydrogenation catalyst include a Raney nickel catalyst; a heterogeneous catalyst in which metals such as Pt, Pd, Ru, Rh, and Ni are supported on a carrier such as carbon, alumina, and diatomaceous earth; , a Ziegler-Natta catalyst consisting of a combination of an organometallic compound consisting of a Group 10 metal and an organoaluminium compound such as triethylaluminum or triisobutylaluminum or an organolithium compound; Examples include metallocene catalysts made of a combination of a dienyl compound and an organometallic compound containing lithium, sodium, potassium, aluminum, zinc, or magnesium.
(3) A (meth)acrylic acid halide ((meth)acrylic acid chloride, etc.) or (meth)acrylic acid anhydride is added to 1 mol of the terminal hydroxyl group-modified conjugated diene polymer represented by the general formula (V). By reacting, the following general formula (I)

(In the formula, R ¹ , R ² , A ¹ , and a have the same meanings as above.)
A (meth)acryloyl-terminated conjugated diene polymer (aI) represented by the following formula is produced.

[(meth)acryloyl-terminated conjugated diene polymer (a-II)]
Each symbol in formula (II) will be explained. R ³ is a hydrogen atom or a methyl group, preferably a hydrogen atom. R ⁴ and R ⁵ each independently represent a divalent unsubstituted or substituted hydrocarbon group, and the hydrocarbon group is an aliphatic, aromatic and/or alicyclic carbonated group having 6 to 20 carbon atoms. A hydrogen group is preferred. R ⁶ is an alkylene group having 2 to 4 carbon atoms, and examples thereof include ethylene group, 1,3-propylene group, 1,2-propylene group, 1,4-butylene group, and 2-methyl-1,3-propylene group. and 1,1-dimethylethylene group, with ethylene group being preferred. b is 1 or 2, preferably 2.

Furthermore, in formula (II), the group A ² is a polymer of a conjugated diene compound and its hydrogenated product, and is the same as the group A ¹ .

When R ⁴ and R ⁵ are aliphatic hydrocarbon groups, examples include linear or branched alkylene groups and alkenylene groups. Examples of the alkylene group include hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, and hexamethylene group. Examples include decamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group, and eicosamethylene group. Examples of the alkenylene group include 1-hexenylene group, 2-hexenylene group, and 3-hexenylene group.

When R ⁴ and R ⁵ are alicyclic hydrocarbon groups, examples include a cycloalkylene group and a cycloalkenylene group. Examples of the cycloalkylene group include a cyclohexylene group, a methylcyclohexylene group, a methylcyclohexylene group, a dimethylcyclohexylene group, a cycloheptylene group, and a cyclooctylene group. Examples of the cycloalkenylene group include a cyclohexenylene group, a cycloheptenylene group, a cyclooctenylene group, a cyclononenylene group, and a cyclodecenylene group.

When R ⁴ and R ⁵ are aromatic hydrocarbon groups, an example thereof is an arylene group. Examples of the arylene group include a phenylene group, tolylene group, methylphenylene group, xylylene group, naphthylene group, anthracenylene group, phenanthrylene group, biphenylene group, and fluorenylene group.

These hydrocarbon groups include isomers, if any, as long as they have the effects of the present invention. Further, the hydrocarbon group may be a combination of two or more selected from the group consisting of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group, such as an alkylene group. A combination of a group and an arylene group; a combination of a cycloalkylene group and an arylene group; a combination of an alkylene group and a cycloalkylene group; a combination of an alkylene group, a cycloalkylene group, and an arylene group.

The number of substituents that the hydrocarbon group has is usually 1 to 10, preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4. Examples of substituents for the hydrocarbon group include halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom); hydroxy group, amino group, linear or branched alkyl group having 1 to 12 carbon atoms. ; linear or branched alkoxy groups having 1 to 12 carbon atoms; aryl groups having 6 to 14 carbon atoms; and cycloalkyl groups having 3 to 20 carbon atoms. These substituents may be contained singly or in combination of two or more. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, sec-pentyl group, group, neopentyl group, n-hexyl group, isohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group and the like. Examples of alkoxy groups include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, n- -decyloxy group, n-dodecyloxy group, etc. Examples of the aryl group include phenyl group, biphenyl group, indenyl group, naphthyl group, anthryl group, phenanthryl group, fluorenyl group, tolyl group, xylyl group, trimethylphenyl group, ethylphenyl group, isopropylphenyl group, tetramethylphenyl group, etc. Can be mentioned. Examples of the cycloalkyl group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group, cyclotridecyl group, cyclotetradecyl group, cyclopentadecyl group, and cyclohexyl group. Examples include sadecyl group, cycloheptadecyl group, cyclooctadecyl group, cyclononadecyl group, and cycloicosyl group. In addition, if these substituents have isomers, such isomers are included as long as they have the effects of the present invention.

The terminal (meth)acryloyl-modified conjugated diene polymer (a-II) is a diisocyanate compound represented by the general formula: R ⁵ -(NCO) ₂ (R ⁵ has the same meaning as above), as described later. Preferred specific examples of R ⁵ include isophorone group, tolylene group, 4,4'-diphenylmethane group, naphthylene group, xylylene group, phenylene group, 3,3'-dichloro-4 , 4'-phenylmethane group, toluylene group, hexamethylene group, 4,4'-dicyclohexylmethane group, hydrogenated xylylene group, triphenylenemethane group, and tetramethylxylene group.

The method for producing the terminal (meth)acryloyl-modified conjugated diene polymer (a-II) is not particularly limited, and regardless of the production method, the compound represented by the above general formula (II) and stereolithography containing the compound can be used. Although the resin composition for use in resin compositions is included within the scope of the present invention, the (meth)acryloyl-terminated conjugated diene polymer (a-II) can preferably be produced by the following method.

（式中、Ｒ⁵は上記と同一意味を有する。）
で表されるジイソシアネート１モルに対して、下記一般式（ＶＩＩ）

（式中、Ｒ³及びＲ⁴は上記と同一意味を有する。）
で表される水酸基含有（メタ）アクリレートを、一般式（ＶＩ）の一方のイソシアネート基と反応させて、下記一般式（ＶＩＩＩ）

（式中、Ｒ³、Ｒ⁴及びＲ⁵は上記と同一意味を有する。）
で表されるイソシアネート基含有（メタ）アクリレートを生成し；次いで <Typical manufacturing method example of terminal (meth)acryloyl-modified conjugated diene polymer (a-II)>
(4) General formula (VI) below

(In the formula, R ⁵ has the same meaning as above.)
For 1 mole of diisocyanate represented by the following general formula (VII)

(In the formula, R ³ and R ⁴ have the same meanings as above.)
A hydroxyl group-containing (meth)acrylate represented by is reacted with one isocyanate group of general formula (VI) to form the following general formula (VIII).

(In the formula, R ³ , R ⁴ and R ⁵ have the same meanings as above.)
to produce an isocyanate group-containing (meth)acrylate represented by;

（式中、Ｒ⁶、Ａ²、及びｂは上記と同一意味を有する。）
で表される末端水酸基変性共役ジエン重合体と反応させることによって、下記一般式（ＩＩ）

（式中、Ｒ³、Ｒ⁴、Ｒ⁵、Ｒ⁶、Ａ²、及びｂは上記と同一意味を有する。）
で表される末端（メタ）アクリロイル変性共役ジエン重合体（ａ－ＩＩ）を製造する。 (5) The isocyanate group-containing (meth)acrylate represented by the general formula (VIII) obtained in (4) above is converted into the following general formula: (IX)

(In the formula, R ⁶ , A ² , and b have the same meanings as above.)
By reacting with a terminal hydroxyl group-modified conjugated diene polymer represented by the following general formula (II)

(In the formula, R ³ , R ⁴ , R ⁵ , R ⁶ , A ² and b have the same meanings as above.)
A (meth)acryloyl-terminated conjugated diene polymer (a-II) represented by is produced.

In the reaction (4) above, the hydroxyl group-containing (meth)acrylate represented by the general formula (VII) is optionally treated with a tertiary amine (for example, triethylamine, pyridine, 4-N,N-dimethylpyridine, -pyrrolidinopyridine), organotin catalysts (e.g. dibutyltin compounds such as di-n-butyltin dilaurate, dibutyltin diacetate, dibutyltin maleate), cationic and anionic catalysts (e.g. tin (Sn), titanium (Ti) , alkyl metals such as aluminum (Al), antimony (Sb), germanium (Ge), zirconium (Zr), and zinc (Zn), compounds such as metal oxides, halides, carboxylates, alkoxides, etc.), etc. It is preferable to react with the diisocyanate represented by the general formula (VI), thereby making it possible to smoothly obtain the isocyanate group-containing (meth)acrylate represented by the above-mentioned general formula (VIII). The reaction temperature is preferably 20 to 80°C.

In the reaction (5) above, the terminal hydroxyl group-modified conjugated diene polymer represented by the general formula (IX) is reacted with the isocyanate group-containing (meth)acrylate represented by the general formula (VIII) in the same manner as in (4). It is preferable to do this, and thereby the terminal (meth)acryloyl-modified conjugated diene polymer (a-II) represented by the above general formula (II) can be smoothly obtained. The reaction temperature is preferably 20 to 80°C.

Generally, both the (meth)acryloyl-terminated conjugated diene polymer (a-I) and the (meth)acryloyl-terminated conjugated diene polymer (a-II) exhibit a low-viscosity liquid to a high-viscosity liquid at room temperature. By selecting and combining appropriate ones as the (meth)acrylamide compound (B) and the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton, A low-viscosity stereolithography resin composition that is easy to handle can be prepared. In addition, the terminal (meth)acryloyl-modified conjugated diene polymer (A), the (meth)acrylamide compound (B), and the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (meth) which does not contain a polymer skeleton ( By combining C), it is possible to prepare a resin composition for stereolithography that has excellent stress retention, toughness, and water resistance of a cured product when modeled by optical stereolithography.

The stereolithography resin composition of the present invention includes a terminal (meth)acryloyl-modified conjugated diene polymer (a-I) and a terminal (meth)acryloyl-modified conjugated diene polymer (A). It may contain only one type of polymer (a-II), or it may contain two types. Among these, the terminal (meth)acryloyl-modified conjugated diene polymer (a-II) is preferred from the viewpoint of better curability of the stereolithographic resin composition, toughness and water resistance of the cured product. The number average molecular weight of the (meth)acryloyl-terminated conjugated diene polymer (A) is preferably in the range of 500 to 10,000, preferably in the range of 750 to 5,000, and preferably in the range of 1,000 to 3 ,000 is more preferable. When the number average molecular weight of the terminal (meth)acryloyl-modified conjugated diene polymer (A) is 500 or more, the cured product of the stereolithography resin composition tends to have high toughness, and when it is 10,000 or less , the stereolithography resin composition tends to have appropriate fluidity.

The content of the (meth)acryloyl-terminated conjugated diene polymer (A) is determined from the viewpoint of excellent stress retention, toughness, and water resistance. (B), the total amount of the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton, and other polymerizable monomers (hereinafter referred to as "total amount of polymerizable components") ) is 100% by mass, it is preferably 1 to 25% by mass, more preferably 2.5 to 20% by mass, and even more preferably 5 to 15% by mass. .

[(meth)acrylamide compound (B)]
The (meth)acrylamide compound (B) is used to reduce the viscosity of the stereolithography resin composition of the present invention and to impart strength to the cured product.

The (meth)acrylamide compound (B) of the present invention is not particularly limited, but when combined with an alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton, A monofunctional (meth)acrylamide group having one (meth)acrylamide group has good miscibility with the (meth)acryloyl-terminated conjugated diene polymer (A) and excellent toughness of the cured product of the stereolithography resin composition. ) Acrylamide compounds are preferred. In addition, the (meth)acrylamide compound (B) is not particularly limited, but when combined with an alicyclic polyfunctional (meth)acrylate-based polymerizable monomer (C) that does not contain a polymer skeleton A monofunctional acrylamide compound having one acrylamide group is more preferable because it has good miscibility with the (meth)acryloyl-modified conjugated diene polymer (A) and excellent curability of the stereolithography resin composition. Moreover, it is preferable that the (meth)acrylamide group that the (meth)acrylamide compound (B) has is a tertiary amide group. The substituent included in the tertiary amide group is preferably a linear or branched alkyl group having 1 to 8 carbon atoms. The number of carbon atoms in the alkyl group is preferably 1 to 6, more preferably 1 to 5, even more preferably 1 to 4. In a preferred embodiment, the (meth)acrylamide compound (B) includes a (meth)acrylamide compound having a tertiary amide group and a tertiary amino group in one molecule. In another preferred embodiment, the (meth)acrylamide compound (B) contains a (meth)acrylamide compound that does not have an amino group but has a tertiary amide group.

Examples of the (meth)acrylamide compound (B) used in the stereolithography resin composition of the present invention include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-di- n-propyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N,N-di-n-butyl (meth)acrylamide, N,N-di-n-hexyl (meth)acrylamide, N,N-di- n-octyl(meth)acrylamide, N,N-di-2-ethylhexyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N,N-bis(2-hydroxyethyl)(meth)acrylamide , N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N-dipropylaminoethyl (meth)acrylamide, N,N-dibutylaminoethyl (meth)acrylamide, N , N-dimethylaminopropyl (meth)acrylamide, N,N-diethylaminopropyl (meth)acrylamide, N,N-dipropylaminopropyl (meth)acrylamide, N,N-dibutylaminopropyl (meth)acrylamide, N,N -Dimethylaminobutyl (meth)acrylamide, N,N-diethylaminobutyl (meth)acrylamide, N,N-dipropylaminobutyl (meth)acrylamide, N,N-dibutylaminobutyl (meth)acrylamide, N-acryloylmorpholine, etc. can be mentioned. One type of (meth)acrylamide compound (B) may be used alone, or two or more types may be used in combination. Among these, N,N-diethyl (meth)acrylamide, N,N-di-n-propyl (meth)acrylamide, N,N-di-n-butyl (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N , N-diethylaminopropyl (meth)acrylamide, N,N-dimethylaminobutyl (meth)acrylamide, N,N-diethylaminobutyl (meth)acrylamide are more preferred, N,N-diethyl (meth)acrylamide, N,N- More preferred are dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, and N,N-diethylaminopropyl (meth)acrylamide, with N,N-diethyl (Meth)acrylamide, N,N-dimethylaminoethyl acrylamide, N,N-diethylaminoethyl acrylamide, N,N-dimethylaminopropylacrylamide, N,N-diethylaminopropylacrylamide are particularly preferred, and N,N-diethylaminopropylacrylamide is the most preferred. preferable.

The content of the (meth)acrylamide compound (B) is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and 30 to 70% by mass when the total amount of polymerizable components is 100% by mass. More preferred. Regarding the content of the (meth)acrylamide compound (B), the compatibility when combined with the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton, From the viewpoint of curability of the resin composition for stereolithography, the content is preferably higher than the content of the terminal (meth)acryloyl-modified conjugated diene polymer (A), and the content of the terminal (meth)acryloyl-modified conjugated diene polymer (A): ( The mass ratio of the meth)acrylamide compound (B) (A):(B) is more preferably 1:1.1 to 1:20, and even more preferably 1:1.5 to 1:15.

[Alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton]
Alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton (hereinafter referred to as "alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C)") C)" or "polymerizable monomer (C)") is used in the stereolithography resin composition of the present invention to impart strength and water resistance. In addition, since the terminal (meth)acryloyl-modified conjugated diene polymer (A) has extremely low polarity and the (meth)acrylamide compound (B) has high polarity, the terminal (meth)acryloyl-modified conjugated diene polymer (A) and The (meth)acrylamide compound (B) is not compatible, but the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) is compatible, resulting in a low viscosity and uniform stereolithography resin composition. can get things. In general, when a polyfunctional (meth)acrylic acid ester polymerizable monomer is blended, it tends to become brittle and tend to impair toughness, but alicyclic polyfunctional (meth)acrylic acid ester polymerization The structural monomer (C) has a more flexible structure than the polyfunctional (meth)acrylic acid ester polymerizable monomer containing an aromatic ring, so it is less prone to embrittlement and less likely to impair toughness. . Furthermore, the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) has no π-electron interaction unlike aromatic ring-containing compounds, so it has a low viscosity and has excellent formability. This tends to make it easier to obtain a resin composition for stereolithography. A preferred embodiment includes a resin composition for stereolithography that does not substantially contain a polyfunctional (meth)acrylic acid ester polymerizable monomer containing an aromatic ring. "Substantially not containing a polyfunctional (meth)acrylic acid ester polymerizable monomer containing an aromatic ring" means The content of the acrylic ester polymerizable monomer is preferably less than 5% by mass, more preferably less than 1% by mass, and even more preferably less than 0.1% by mass. The polyfunctional (meth)acrylic acid ester polymerizable monomer containing an aromatic ring is not particularly limited, and includes di(meth)acrylate having a bisphenol A skeleton (such as ethoxylated bisphenol A di(meth)acrylate) etc. "Contains no polymer skeleton" means that it does not contain a repeating structure formed by polymerizing monomers, including dimers, trimers, oligomers, etc. For example, an alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer containing a poly(oxyalkylene) group contains a poly(oxyalkylene) group, which is a repeating structure of polymerized alkylene oxides, so it does not polymerize. It is not included in the sexual monomer (C). On the other hand, ethylene oxide-modified hydrogenated bisphenol A dimethacrylate is a polymerizable monomer (C) because a compound having one ethylene oxide unit bonded to each cyclohexane ring via an oxygen atom does not correspond to a polymer skeleton. included.

As the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C), there is no particular restriction on the number of functional groups (the number of (meth)acryloyloxy groups) as long as it is polyfunctional. From the viewpoint of mechanical strength of the obtained cured product, the number of (meth)acryloyloxy groups in one molecule is preferably 2 to 10, more preferably 2 to 6, and 2 to 4. More preferably, it is 2 or 3, most preferably 2.

There is no particular restriction on the type of alicyclic skeleton possessed by the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C), and various alicyclic skeletons that do not belong to aromatic rings may be used. can. An alicyclic skeleton is a compound that is composed only of carbon atoms and hydrogen atoms, and the carbon atoms are bonded in a ring, and may be a saturated compound or an unsaturated compound, but it must be a saturated compound. is preferred.

The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) is, for example, a monoalicyclic polyfunctional (meth)acrylic acid ester having a monoalicyclic structure as an alicyclic skeleton. Examples include polymerizable monomers and polyalicyclic polyfunctional (meth)acrylic acid ester polymerizable monomers having a polyalicyclic structure as an alicyclic skeleton. When the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) contains a monoalicyclic structure and a polyalicyclic structure, the polyalicyclic polyfunctional (meth)acrylic acid ester type Included in polymerizable monomers. Examples of the monoalicyclic structure include cycloalkane rings such as a cyclopentane ring, cyclohexane ring, and cyclooctane ring; and cycloalkene rings such as a cyclopentene ring, cyclohexene ring, and cyclooctadiene ring. Examples of the polyalicyclic structure include spiro structures such as a tricyclodecane ring (for example, a tricyclo[5.2.1.0 ^2,6 ]decane ring, etc.), a norbornane ring, an adamantane ring, and a decahydronaphthalene ring. Non-containing polycyclic cycloalkane rings; examples include spiro rings such as a spiro[3.4]octane ring, a spiro[4.4]nonane ring, and a spiro[4.5]decane ring. Among these alicyclic skeletons, polyalicyclic structures are preferred, and polycyclic cycloalkane rings that do not contain a spiro structure are more preferred, from the viewpoint of stress retention, toughness, etc. of the resulting cured product. The number of rings in the polyalicyclic structure is preferably 2 to 5, more preferably 2 to 4, and even more preferably 2 to 3. Specific examples of the heterocyclic skeleton include, for example, a tetrahydrofuran ring, a tetrahydropyran ring, an imidazolidine ring, a piperidine ring, and a morpholine ring. When the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) contains a polyfunctional (meth)acrylic acid ester polymerizable monomer having a monoalicyclic structure, the The number of monoalicyclic rings contained in the polymerizable monomer may be one, or two or more (for example, two cycloalkane rings).

In the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C), the alicyclic skeleton may exist as a monovalent group, but it may not exist as a divalent or higher group. It is preferable that it exists as a divalent group. When present as a divalent or higher group, some of the plurality of bonding sites (bonds) may be bonded to a substituent such as an alkyl group, such as an isobornane ring, etc. Examples include.

There is no particular restriction on the number of alicyclic skeletons that the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) has, and it may have only one, or it may have two or more. You may do so. The total number of carbon atoms constituting the alicyclic skeleton in the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) is 5 to 5, since the effects of the present invention are significantly superior. It is preferably 20, more preferably 6-18, even more preferably 8-12, and particularly preferably 9-11.

The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) preferably does not contain a urethane bond, from the viewpoint of water resistance of the resulting cured product of the stereolithography resin composition, It is more preferable that it does not contain hydroxy groups, carboxy groups, sulfonic acid groups, sulfinic acid groups, phosphoric acid groups, primary and secondary amino groups, and urethane bonds. Since these functional groups contain hydrogen bonded to a heteroatom, they have high polarity, and the cured product of the stereolithography resin composition of the present invention tends to absorb water, leading to a decrease in water resistance.

Examples of the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) of the present invention include tricyclodecane dimethanol di(meth)acrylate, adamantanediol di(meth)acrylate, and adamantanetriol di(meth)acrylate. meth)acrylate, cyclohexanedimethanol di(meth)acrylate, etc. Among these, tricyclodecane dimethanol di(meth)acrylate is used from the viewpoint of not impairing the toughness of the cured product of the stereolithography resin composition and having excellent strength. Preferred are meth)acrylate and adamantane diol di(meth)acrylate, and more preferred is tricyclodecane dimethanol di(meth)acrylate. The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) may be used alone or in combination of two or more.

The content of the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) is based on the total amount of polymerizable components being 100% by mass. The content of the acid ester polymerizable monomer (C) is preferably 1.0 to 60% by mass, more preferably 5.0 to 50% by mass, and even more preferably 10 to 40% by mass. If the content of the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton is 50% by mass or less, the flexibility of the cured product of the stereolithography resin composition will decrease. The properties become better. In addition, the content of the alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) is the content of the terminal (meth)acryloyl-modified conjugated diene polymer (A) and the (meth)acrylamide compound (B). ) and the curability of the stereolithography resin composition, the total mass of the terminal (meth)acryloyl-modified conjugated diene polymer (A) and the (meth)acrylamide compound (B) (hereinafter referred to as " The total mass of the polymer (A) and the compound (B) is preferably less than the total mass of the polymer (A) and the compound (B), and the total mass of the polymerizable monomer (C) The mass ratio of (A)+(B):(C)=9:1 to 5.5:4.5 is more preferable, and even more preferably 8.5:1.5 to 6:4.

The resin composition for stereolithography of the present invention includes an alicyclic polyfunctional (meth)acrylic acid ester polymer that does not contain a (meth)acrylamide compound (B) and a polymer skeleton within the scope of the invention. Polymerizable monomers other than the polymerizable monomer (C) can be included. Examples of such polymerizable monomers include monofunctional (meth)acrylic acid ester, α-cyanoacrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, and itaconic acid. Examples include esters such as, vinyl esters, vinyl ethers, mono-N-vinyl derivatives, and styrene derivatives.

The polymerizable components contained in the resin composition for stereolithography of the present invention are substantially a terminal (meth)acryloyl-modified conjugated diene polymer (A), a (meth)acrylamide compound (B), and an alicyclic polyfunctional ( It may be composed only of the meth)acrylic acid ester polymerizable monomer (C). The polymerizable components are substantially a terminal (meth)acryloyl-modified conjugated diene polymer (A), a (meth)acrylamide compound (B), and an alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer ( C) is composed only of a terminal (meth)acryloyl-modified conjugated diene polymer (A), a (meth)acrylamide compound (B), and an alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer. The content of other polymerizable components other than polymerizable components (C) is less than 10.0% by mass, preferably less than 5.0% by mass, and more It means preferably less than 1.0% by weight, more preferably less than 0.1% by weight, particularly preferably less than 0.01% by weight.

[Photopolymerization initiator (D)]
The photopolymerization initiator (D) used in the present invention can be selected from polymerization initiators used in general industry, and among them, photopolymerization initiators used in dental applications are preferably used.

As the photopolymerization initiator (D), (bis)acylphosphine oxides, thioxanthone or quaternary ammonium salts of thioxanthone, ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, Examples include α-aminoketone compounds and germanium compounds. These may be used alone or in combination of two or more.

Among these photopolymerization initiators (D), it is preferable to use at least one selected from the group consisting of (bis)acylphosphine oxides (including salts) and α-diketones. As a result, the resin for stereolithography has excellent photocurability in the ultraviolet and visible light regions, and exhibits sufficient photocurability using any light source: laser, halogen lamp, light emitting diode (LED), or xenon lamp. A composition is obtained.

Among the (bis)acylphosphine oxides, examples of the acylphosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, and 2,6-dichlorobenzoyldiphenylphosphine oxide. , 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, benzoyldi(2,6-dimethylphenyl) ) phosphonate, the sodium salt of 2,4,6-trimethylbenzoyl phenylphosphine oxide, the potassium salt of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the ammonium salt of 2,4,6-trimethylbenzoyldiphenylphosphine oxide. . 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 examples include compounds described in JP-A No. 2000-159621.

Among these (bis)acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine It is particularly preferable to use oxide and sodium salt of 2,4,6-trimethylbenzoylphenylphosphine oxide as the photopolymerization initiator (D).

Examples of α-diketones include diacetyl, benzyl, camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4'-oxybenzyl, and acenaphthenequinone. Among these, camphorquinone is particularly preferred when a light source in the visible light region is used.

Examples of germanium compounds include monoacylgermanium compounds such as benzoyltrimethylgermanium (IV); diacylgermanium compounds such as dibenzoyldiethylgermanium and bis(4-methoxybenzoyl)-diethylgermanium.

The content of the photopolymerization initiator (D) in the stereolithography resin composition of the present invention is not particularly limited, but from the viewpoint of curability of the resulting stereolithography resin composition, the total amount of polymerizable components is 100 parts by mass. It is preferably 0.1 to 20 parts by mass. If the content of the photopolymerization initiator (D) is less than 0.1 parts by mass based on the total amount of 100 parts by mass, polymerization may not proceed sufficiently and a molded article may not be obtained. The content of the photopolymerization initiator (D) is more preferably 0.5 parts by mass or more, and even more preferably 1.0 parts by mass or more, based on 100 parts by mass of the total amount. On the other hand, if the content of the photopolymerization initiator (D) exceeds 20 parts by mass based on the total amount of 100 parts by mass, or if the photopolymerization initiator itself has low solubility, This may lead to precipitation of the photopolymerization initiator. The content of the photopolymerization initiator (D) is more preferably 10 parts by mass or less, and even more preferably 7.5 parts by mass or less, based on the total amount of 100 parts by mass.

The stereolithography resin composition of the present invention comprises the above-mentioned terminal (meth)acryloyl-modified conjugated diene polymer (A), (meth)acrylamide compound (B), an alicyclic polyfunctional (meth) ) There is no particular limitation as long as it contains the acrylic ester polymerizable monomer (C) and the photopolymerization initiator (D), and for example, it may contain other components. The resin composition for stereolithography of the present invention can be manufactured according to a known method.

The resin composition for stereolithography of the present invention can contain a polymerization accelerator for the purpose of improving photocurability within a range that does not impair the spirit of the present invention. Examples of the polymerization accelerator include ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, and n-4-(N,N-dimethylamino)benzoate. butoxyethyl, 2-(methacryloyloxy)ethyl 4-(N,N-dimethylamino)benzoate, 4-(N,N-dimethylamino)benzophenone, butyl 4-(N,N-dimethylamino)benzoate, etc. Examples include amine compounds. Among these, ethyl 4-(N,N-dimethylamino)benzoate and n-butoxy 4-(N,N-dimethylamino)benzoate are used from the viewpoint of imparting excellent curability to the resin composition for stereolithography. At least one selected from the group consisting of ethyl and 4-(N,N-dimethylamino)benzophenone is preferably used.

The stereolithography resin composition of the present invention may further contain a filler in order to adjust the paste properties or to increase the mechanical strength of the cured product of the stereolithography resin composition. Examples of fillers include organic fillers, inorganic fillers, and organic-inorganic composite fillers. One type of filler may be used alone, or two or more types may be used in combination.

Examples of organic filler materials include polymethyl methacrylate, polyethyl methacrylate, 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, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene Examples include copolymers. These may be used alone or in combination of two or more. The shape of the organic filler is not particularly limited, and the particle size of the filler can be appropriately selected and used.

Examples of inorganic filler materials include quartz, silica, alumina, silica-titania, 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, strontium calcium fluoroaluminosilicate glass are listed. It will be done. These may also be used alone or in combination of two or more. The shape of the inorganic filler is not particularly limited, and an amorphous filler or a spherical filler can be appropriately selected and used.

Other polymers can be added to the stereolithography resin composition of the present invention for the purpose of modifying flexibility, fluidity, etc. within a range that does not impair the spirit of the present invention. For example, natural rubber, synthetic polyisoprene rubber, liquid polyisoprene rubber and its hydrogenated product, polybutadiene rubber, liquid polybutadiene rubber and its hydrogenated product, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, isoprene- Isobutylene rubber, acrylonitrile-butadiene rubber, or styrenic elastomer can be added. Specific examples of other polymers that can be added include polystyrene-polyisoprene-polystyrene block copolymer, polystyrene-polybutadiene-polystyrene block copolymer, poly(α-methylstyrene)-polybutadiene-poly(α-methylstyrene) ) block copolymers, styrenic block copolymers such as poly(p-methylstyrene)-polybutadiene-poly(p-methylstyrene) block copolymers, and hydrogenated products thereof. A preferred embodiment includes a stereolithography resin composition that does not substantially contain other polymers (including prepolymers). "Substantially not containing" other polymers means that the content of other polymers in the stereolithography resin composition is less than 5% by mass, preferably less than 1% by mass, and 0.1% by mass. It is more preferably less than 0.01% by mass.

The stereolithography resin composition of the present invention may contain a softener, if necessary. Examples of the softener include petroleum-based softeners such as paraffinic, naphthenic, and aromatic process oils, and vegetable oil-based softeners such as paraffin, peanut oil, and rosin. These softeners may be used alone or in combination of two or more. The content of the softener is not particularly limited as long as it does not impair the spirit of the present invention, but it 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 polymerizable components.

Furthermore, a known stabilizer can be added to the stereolithography resin composition of the present invention for the purpose of suppressing deterioration or adjusting photocurability. Examples of such stabilizers include polymerization inhibitors, ultraviolet absorbers, and antioxidants. One type of stabilizer may be used alone, or two or more types may be used in combination.

Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutylhydroquinone, dibutylhydroquinone monomethyl ether, t-butylcatechol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butylphenol, 3,5-di-t-butyl-4-hydroxytoluene is mentioned. One type of polymerization inhibitor may be used alone, or two or more types may be used in combination. The content of the polymerization inhibitor is preferably 0.1 to 5.0 parts by mass based on 100 parts by mass of the total amount of polymerizable components.

Furthermore, known additives can be added to the stereolithography resin composition of the present invention for the purpose of adjusting color tone or paste properties. Examples of such additives include colorants (pigments, dyes), organic solvents, and thickeners. One type of additive may be used alone, or two or more types may be used in combination.

The stereolithography resin composition of the present invention has excellent moldability, and has excellent stress retention properties, toughness, and water resistance after curing. Therefore, the resin composition for stereolithography of the present invention can be applied to applications where such advantages can be utilized, and is particularly suitable for dental aligners, dental occlusal splints, and therapeutic devices for sleep apnea syndrome. The shape of a cured product using the stereolithography resin composition of the present invention can be changed depending on each use. In addition, the resin composition for stereolithography of the present invention may be used for each component (terminally (meth)acryloyl-modified Conjugated diene polymer (A), (meth)acrylamide compound (B), alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer containing no polymer skeleton (C), polymerization initiator (D) ) and various optional components (polymerizable components other than (A), (B), and (C), polymerization accelerator (E), filler, other polymers, softeners, stabilizers, additives, etc.)) The type and content of can be adjusted. The three-point bending strength of the cured product obtained from the stereolithography resin composition of the present invention is not particularly limited, and is preferably 30 MPa or more, more preferably 40 MPa or more, and 50 MPa or more. is even more preferable. The three-point bending strength of the cured product may be 150 MPa or less. The flexural modulus of the cured product obtained from the stereolithography resin composition of the present invention is not particularly limited, but is preferably in the range of 0.3 to 3.0 GPa, and preferably in the range of 0.5 to 2.5 GPa. More preferably, it is in the range of 0.8 to 2.0 GPa.

The stereolithography resin composition of the present invention can be used for various purposes by taking advantage of its properties of producing molded products or three-dimensional objects with excellent stress retention, toughness, and water resistance after curing, as well as other cured products. It can be used for manufacturing various molded products, for coating, for vacuum forming molds, etc.

When performing optical stereolithography using the resin composition for stereolithography of the present invention, conventionally known optical stereolithography methods (for example, suspended liquid bath stereolithography) and devices (for example, DigitalWax (manufactured by DWS)) are used. Any stereolithography machine such as 028J-Plus (registered trademark) can be used. Among these, in the present invention, it is preferable to use active energy rays as the light energy for curing the resin. "Active energy rays" refer to energy rays capable of curing the photocurable resin composition, such as ultraviolet rays, electron beams, X-rays, radiation, and high frequency waves. For example, the active energy light may be ultraviolet light having a wavelength of 300-400 nm. Examples of the light source of the active energy beam include lasers such as Ar laser and He-Cd laser; illumination such as halogen lamps, xenon lamps, metal halide lamps, LEDs, mercury lamps, and fluorescent lamps; lasers are particularly preferred. When a laser is used as a light source, it is possible to increase the energy level and shorten the modeling time, and by taking advantage of the laser beam's good focusing ability, it is possible to obtain three-dimensional objects with high modeling accuracy. can.

As described above, when performing optical stereolithography using the resin composition for stereolithography of the present invention, any conventionally known method or conventionally known stereolithography system device can be employed, but there are no particular limitations. A typical example of the optical stereolithography method preferably used in the invention is to form a cured layer by selectively irradiating a stereolithography resin composition with active energy rays so as to obtain a cured layer having a desired pattern. Next, a laminating step of supplying an uncured liquid stereolithography resin composition to the cured layer and similarly irradiating active energy rays to form a new cured layer continuous with the cured layer. One example is a method of repeatedly obtaining the desired three-dimensional object. In addition, the resulting three-dimensional object may be used as is, or in some cases, it may be further subjected to post-curing by light irradiation or heat to improve its mechanical properties or shape stability. You may also use it.

The present invention includes embodiments in which the above configurations are combined in various ways within the scope of the technical idea of the present invention as long as the effects of the present invention are achieved.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples in any way, and many modifications may be made within the scope of the technical idea of the present invention. This can be done by a person having ordinary knowledge in the field.

[Synthesis Example 1] [Production of (meth)acryloyl-terminated conjugated diene polymer (a-I-1)]
In a 5 L SUS autoclave under an air atmosphere, 160 g of acrylic acid chloride, 200 g of pyridine, and hydrogenated polybutadiene "GI-1000" modified with a hydroxyl group at the terminal (number average molecular weight: 1,500, Mw/Mn: 1.15 , 1,2-bond unit content: 7 mol %, hydrogenation rate determined by iodine value measurement: 96 mol %, manufactured by Nippon Soda Co., Ltd.) (1500 g) and reacted at 60° C. for 48 hours. The reaction solution was diluted with 1 L of toluene, washed three times with 0.5 L of distilled water, reprecipitated with a 50/50 (volume ratio) solvent of distilled water/methanol, and dried under reduced pressure to obtain acryloyl-terminated hydrogenated polybutadiene ( aI-1) was obtained. The resulting acryloyl-terminated hydrogenated polybutadiene (a-I-1) was subjected to IR measurement, and absorption of carbonyl groups at 1735 cm ^-1 (CO) was confirmed. The number average molecular weight (Mn) of the obtained acryloyl-terminated hydrogenated polybutadiene (a-I-1) was measured by GPC method and found to be 2,600.

[Synthesis Example 2] [Production of (meth)acryloyl-terminated conjugated diene polymer (a-II-1)]
In a 5 L SUS autoclave, 390 g of isophorone diisocyanate, 3.5 g of aluminum chelate M, and 200 g of 2-hydroxyethyl acrylate were mixed in an air atmosphere and reacted at 60° C. for 1 hour to synthesize reaction product A. Next, in an air atmosphere, 600 g of the previously synthesized reactant A and hydrogenated polybutadiene "GI-1000" modified with a hydroxyl group at the terminal (number average molecular weight: 1,500, Mw/Mn: 1.15, 1 , 2-bond unit content: 7 mol%, hydrogenation rate by iodine value measurement: 96 mol%, manufactured by Nippon Soda Co., Ltd.) and 12.0 g of aluminum chelate M were mixed and reacted at 60°C for 2 hours. I let it happen. After confirming that the residual NCO was 0.1% or less, the reaction was terminated, and the reaction solution was diluted with 1 L of toluene, washed three times with 0.5 L of distilled water, and diluted with 50/50 (by volume) of distilled water/methanol. The mixture was reprecipitated with a solvent of (ratio) and dried under reduced pressure to obtain acryloyl-terminated hydrogenated polybutadiene (a-II-1). The obtained acryloyl-terminated hydrogenated polybutadiene (a-II-1) was subjected to ¹ H-NMR measurement, and two NH signals (4.55 ppm, 4.70 ppm) were confirmed. Further, IR measurement was performed to confirm absorption of urethane bonds at 1728 cm ^-1 (CO) and 3339 cm ^-1 (NH). The number average molecular weight (Mn) of the obtained acryloyl-terminated hydrogenated polybutadiene (a-II-1) was measured by GPC method and found to be 2,800. Note that "residual NCO (%)" is the mass of the isocyanate moiety in the mass of the compound (the multiplier of the number of moles and 42.02 (NCO molecular weight)) expressed in %.

[Synthesis Example 3] [Production of (meth)acryloyl-terminated conjugated diene polymer (a-II-2)]
Hydrogenated polybutadiene "GI-3000" which modified GI-1000 with a hydroxyl group at the end (number average molecular weight: 3,100, Mw/Mn: 1.12, content of 1,2-bonding units: 7 mol%, Hydrogenation rate determined by iodine value measurement: 96 mol% (manufactured by Nippon Soda Co., Ltd.) was carried out in the same manner as in Synthesis Example 2, except that the hydrogenation rate was changed to 96 mol% (manufactured by Nippon Soda Co., Ltd.), and the reaction and washing were carried out in the same manner as in Synthesis Example 2. Obtained. The obtained acryloyl-terminated hydrogenated polybutadiene (a-II-2) was subjected to ¹ H-NMR measurement, and two NH signals (4.55 ppm, 4.70 ppm) were confirmed. Further, IR measurement was performed to confirm absorption of urethane bonds at 1728 cm ^-1 (CO) and 3339 cm ^-1 (NH). The number average molecular weight (Mn) of the obtained acryloyl-terminated hydrogenated polybutadiene (a-II-2) was measured by GPC method and found to be 4,200.

[Synthesis Example 4] [Production of (meth)acryloyl-terminated conjugated diene polymer (a-II-3)]
Unhydrogenated polybutadiene "G-1000", which is GI-1000 modified with a hydroxyl group at the end (number average molecular weight: 1,400, Mw/Mn: 1.15, content of 1,2-bonding units: 85 mol% , manufactured by Nippon Soda Co., Ltd.) and isophorone diisocyanate was changed to tolylene diisocyanate, the reaction and washing were carried out in the same manner as in Synthesis Example 2 to obtain acryloyl-terminated unhydrogenated polybutadiene (a-II-3). I got it. The obtained acryloyl-terminated unhydrogenated polybutadiene (a-II-3) was subjected to ¹ H-NMR measurement, and two NH signals (4.55 ppm, 4.70 ppm) were confirmed. Further, IR measurement was performed to confirm absorption of urethane bonds at 1728 cm ^-1 (CO) and 3339 cm ^-1 (NH). The number average molecular weight (Mn) of the obtained acryloyl-terminated hydrogenated polybutadiene (a-II-3) was measured by GPC method and found to be 2,900.

Each component used in the resin composition for stereolithography according to an example or a comparative example will be explained below along with its abbreviations.

[(meth)acrylamide compound (B)]
DEAA: N,N-diethylacrylamide (manufactured by KJ Chemicals Co., Ltd.)
NIPAM: N-isopropylacrylamide (manufactured by KJ Chemicals Co., Ltd.)
ACMO: N-acryloylmorpholine (manufactured by KJ Chemicals Co., Ltd.)
[Alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton]
TCDDMA: Tricyclo[5.2.1.0 ^2,6 ]decane dimethanol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.)
ADDA: Adamantane diol diacrylate (manufactured by Mitsubishi Gas Chemical Co., Ltd.)
CHDDMA: 1,4-cyclohexanediol dimethacrylate (manufactured by Shin Nakamura Chemical Co., Ltd.)

[Photopolymerization initiator (D)]
TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide BAPO: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[Polymerization inhibitor]
BHT: 3,5-di-t-butyl-4-hydroxytoluene

[Examples 1 to 11 and Comparative Examples 1 to 4]
Each component was mixed in the amounts shown in Tables 1 and 2 at room temperature (20°C ± 15°C, JIS (Japanese Industrial Standards) Z 8703:1983), and the ingredients according to Examples 1 to 11 and Comparative Examples 1 to 4 were prepared. A paste was prepared as a resin composition for stereolithography.

<Stress retention>
The cured products of the resin compositions for stereolithography according to each example and each comparative example were measured using a stereolithography machine (DIGITALWAX (registered trademark) 020D manufactured by DWS) to have a length of 60 mm, a width of 20 mm, and a thickness of 1.0 mm. A sheet-like cured product was prepared and punched using a dumbbell-shaped No. 8 punching blade according to JIS K 6251:2010 (Vulcanized rubber and thermoplastic rubber - How to determine tensile properties) to prepare a tensile test piece (n =5). Stress retention (permanent strain) was evaluated using the obtained test piece. Specifically, using a universal testing machine (manufactured by Shimadzu Corporation, EZ Test EZ-SX 500N), the material was pulled by 0.5 mm at a jig distance of 10 mm and a crosshead speed of 20 mm/min, and then held for 24 hours. We then observed the stress decay behavior. In this test, the stress after 24 hours of initial stress is preferably 50% or more, more preferably 60% or more.
Stress retention rate (%) = (stress after 24 hours retention/initial stress) x 100

<Toughness (flexural modulus, bending strength, displacement at break)>
Regarding the cured products of the resin compositions for stereolithography according to each Example and each Comparative Example, test pieces having the dimensions described in JIS T 6501:2012 (acrylic resin for denture bases) (length 64.0 mm, width 10.0 mm) were prepared. 0 mm, thickness 3.3 mm) was prepared, and after being stored in the air for one day, a bending strength test was conducted and evaluated, and this was used as the initial value. That is, a bending strength test was conducted using a universal testing machine (manufactured by Shimadzu Corporation, Autograph AG-I 100 kN) at a crosshead speed of 5 mm/min (n=5). The flexural modulus of the test piece is preferably in the range of 0.3 to 3.0 GPa, more preferably in the range of 0.5 to 2.5 GPa, and even more preferably in the range of 0.8 to 2.0 GPa. The bending strength (3-point bending strength) is preferably 30 MPa or more, more preferably 40 MPa or more, and even more preferably 50 MPa or more. As for the displacement at the breaking point, it is preferable that there is no breaking. Regarding the displacement at the breaking point, the toughness is judged to be good if it does not break until the end or breaks at a displacement of 20 mm or more, and the toughness is judged to be fair if it breaks at a displacement of more than 10 mm but less than 20 mm, and the toughness is judged to be fair if the break occurs at a displacement of 10 mm or less. A case where the toughness was broken was evaluated as "x", and a case of △ or higher was evaluated as "pass".

<Water resistance>
The cured products of the resin compositions for stereolithography according to each Example and each Comparative Example, which were prepared in the same manner as the cured products prepared in the toughness measurement, were stored in air for 1 day and then placed in water at 37°C for 168 hours. After immersion, the bending strength was measured in the same manner as the above bending strength test (n=5). The bending strength measurement result for the above toughness (after storage in air for 1 day) is defined as the "initial bending strength", and the bending strength after 168 hours immersion in water at 37°C (hereinafter referred to as "initial bending strength") , referred to as "bending strength after 168 hours of immersion in water") is excellent in water resistance if it is 10% or less, and even more excellent in water resistance if it is 7% or less.
Rate of change (decrease rate) in bending strength (%) = [{Initial bending strength (MPa) - bending strength after 168 hours of immersion in water (MPa)}/initial bending strength (MPa)] x 100

As shown in Tables 1 and 2, the resin compositions for stereolithography in Examples 1 to 11 were excellent in stress retention, toughness, and water resistance of cured products. In particular, the stress retention properties of the cured products of the resin compositions for stereolithography according to Examples 1 to 11 were superior to those of the resin compositions of Comparative Examples 1, 3, and 4. Furthermore, the strength of the cured products of the stereolithography resin compositions according to Examples 1 to 11 was superior to that of the cured products of the resin compositions according to Comparative Examples 1, 3, and 4. The toughness of the cured products of the stereolithography resin compositions according to Examples 1 to 11 was superior to that of the cured product of Comparative Example 3. The water resistance of the cured products of the stereolithography resin compositions of Examples 1 to 11 was superior to that of the cured products of Comparative Examples 1, 3, and 4.

The stereolithography resin composition of the present invention is particularly suitable for dental mouthpieces because the cured product has excellent stress retention properties, toughness, and water resistance.

Claims (19)

Terminal (meth)acryloyl-modified conjugated diene polymer (A), (meth)acrylamide compound (B), alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton and a photopolymerization initiator (D),
The terminal (meth)acryloyl-modified conjugated diene polymer (A) has the following general formula (I)

(In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 2 to 4 carbon atoms, a is 1 or 2, and A ¹ is a polymer of a conjugated diene compound and/or its It is a hydrogen additive.)
A terminal (meth)acryloyl-modified conjugated diene polymer (a-I) represented by the following general formula (II)

(In the formula, R ³ is a hydrogen atom or a methyl group, R ⁴ and R ⁵ are each independently a divalent unsubstituted or substituted hydrocarbon group, and R ⁶ is an alkylene group having 2 to 4 carbon atoms. (b is 1 or 2, and A ² is a polymer of a conjugated diene compound and/or a hydrogenated product thereof.)
A resin composition for stereolithography containing at least one member selected from the group consisting of (meth)acryloyl-terminated conjugated diene polymers (a-II) represented by: The resin composition for stereolithography according to claim 1, wherein R ² and/or R ⁶ are ethylene groups. The resin composition for stereolithography according to claim 1 or 2, wherein the hydrocarbon groups of R ⁴ and R ⁵ are aliphatic, aromatic and/or alicyclic hydrocarbon groups having 6 to 20 carbon atoms. The terminal (meth)acryloyl-modified conjugated diene polymer (A) contains the terminal (meth)acryloyl-modified conjugated diene polymer (a-II) represented by the general formula (II). The resin composition for stereolithography according to any one of the items. The hydrocarbon group of R ⁵ is an isophorone group, a tolylene group, a 4,4'-diphenylmethane group, a naphthylene group, a xylylene group, a phenylene group, a 3,3'-dichloro-4,4'-phenylmethane group, a tolylene group, Any one of claims 1 to 4, which is at least one member selected from the group consisting of hexamethylene group, 4,4'-dicyclohexylmethane group, hydrogenated xylylene group, triphenylenemethane group, and tetramethylxylene group. The resin composition for stereolithography described in . The polymer of the conjugated diene compound and/or the hydrogenated product of A ¹ and A ² contains at least one selected from the group consisting of a butadiene polymer, an isoprene polymer, and a hydrogenated product thereof. The resin composition for stereolithography according to any one of claims 1 to 5. The stereolithography resin composition according to any one of claims 1 to 6, wherein the terminal (meth)acryloyl-modified conjugated diene polymer and/or its hydrogenated product has a number average molecular weight of 500 to 10,000. The resin composition for stereolithography according to any one of claims 1 to 7, wherein R ¹ and/or R ³ are hydrogen atoms. The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton contains a hydroxy group, a carboxy group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group, a primary The resin composition for stereolithography according to any one of claims 1 to 8, characterized in that it does not contain a secondary amino group or a urethane bond. The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton contains a polyalicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer. The stereolithography resin composition according to any one of claims 1 to 9, comprising: The polyalicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer contains at least one selected from the group consisting of a tricyclodecane ring, a norbornane ring, an adamantane ring, and a decahydronaphthalene ring. The resin composition for stereolithography according to claim 10. The alicyclic polyfunctional (meth)acrylic acid ester polymerizable monomer (C) that does not contain a polymer skeleton is at least one selected from the group consisting of a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring. The stereolithography resin composition according to any one of claims 1 to 9, comprising: The resin composition for stereolithography according to any one of claims 1 to 12, wherein the (meth)acrylamide compound (B) contains a monofunctional (meth)acrylamide compound. The (meth)acrylamide compound (B) is N,N-diethyl (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N-dimethylamino The stereolithography resin composition according to any one of claims 1 to 13, comprising at least one selected from the group consisting of propyl (meth)acrylamide and N,N-diethylaminopropyl (meth)acrylamide. A dental material comprising a cured product of the stereolithography resin composition according to any one of claims 1 to 14. A dental aligner comprising a cured product of the stereolithography resin composition according to any one of claims 1 to 14. A dental occlusal splint comprising a cured product of the stereolithographic resin composition according to any one of claims 1 to 14. A therapeutic device for sleep apnea syndrome, comprising a cured product of the stereolithographic resin composition according to any one of claims 1 to 14. A method for producing a three-dimensional object by optical three-dimensional modeling using the stereolithography resin composition according to any one of claims 1 to 14.