JPH08183822A - Stereolithographic resin - Google Patents

Abstract

PURPOSE: To obtain a resin which can give a three-dimensional molding having excellent dimensional accuracy by mixing a specific unsaturated urethane with at least one specific vinyl monomer in a specific proportion. CONSTITUTION: The resin comprises an unsaturated urethane represented by formula I, II, or III [wherein Z<1> is the residue formed from an urethane di- or triisocyanate by removing the isocyanate groups; Z<2> is the residue formed from a polyurethane di- or triisocyanate by removing the isocyanate groups; Z<3> is the residue formed from a polyol selected among di- and trihydric polyether, polyester, and polyetherester polyols by removing the hydroxyl groups; A<1> and A<2> each is a group represented by formula IV; A<3> is a group represented by formula V (where R<1> and R<2> each is H or CH3 , Y<1> is the residue formed from a dihydric alcohol by removing the hydroxyl groups; and Y<2> is a 2-4C alkylene); and m, n, and p each is 2 or 3] and at least one vinyl monomer comprising either (meth)acrylic morpholide or a mixture thereof with a diol di(meth)acrylate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin for optical three-dimensional modeling. The NC cutting method has been used for the production of various models and fixed objects such as a model for mold making, a model for copying, and a model for die-sinking electric discharge machining. In recent years, these have photopolymerizability. Attention has been paid to an optical three-dimensional modeling method in which a resin for optical three-dimensional modeling is irradiated with energy rays to cure and mold a predetermined three-dimensional model. The present invention relates to an optical three-dimensional molding resin applied to the above-described optical three-dimensional molding method, and particularly to an optical three-dimensional molding resin containing unsaturated urethane.

[0002]

2. Description of the Related Art Conventionally, as an optical three-dimensional molding resin containing unsaturated urethane, 1) an example containing unsaturated urethane obtained from polyurethane diisocyanate and hydroxyalkyl acrylate (JP-A-2-14561).
6) 2) Examples containing unsaturated urethane obtained from polyurethane diisocyanate and triol di (meth) acrylate (JP-A-1-204915, JP-A-63-
35550), 3) Examples containing unsaturated urethane obtained from polyurethane diisocyanate and tetraol triacrylate (JP-A-61-276863), 4).
Examples containing an unsaturated urethane obtained from polyurethane tri-hexaisocyanate and triol di (meth) acrylate (JP-A-63-35550), 5) From triisocyanate and diol mono (meth) acrylate or triol di (meth) acrylate An example containing the obtained unsaturated urethane (Japanese Patent Laid-Open No. 63-11255).
There is an example (Japanese Patent Publication No. 63-20203) containing an unsaturated urethane obtained from 1) and 6) diisocyanate and triol dimethacrylate.

Among these conventional examples, unsaturated compounds having a polymer chain such as a polyoxyalkylene ether chain or a polyester chain, and a soft segment chain such as a polyurethane chain in which such a polymer chain is bonded with diisocyanate are included in the molecule. Some contain urethane. The resin for optical three-dimensional modeling containing unsaturated urethane having a soft segment chain in the molecule has a relatively low content of the polymerizable group, and therefore, the photopolymerization thereof forms a three-dimensional model having a small crosslink density. It is known that volume shrinkage due to photopolymerization is generally small.

However, even if the resin contains unsaturated urethane having a soft segment chain in the molecule, in the conventional optical three-dimensional modeling resin, the three-dimensional molded product obtained is actually excellent in shape accuracy. It doesn't become a thing. The reason is, in addition to the volume contraction based on the photopolymerization described above, the heterogeneity of the material in the resin for optical three-dimensional modeling to be used, the heterogeneity of the photopolymerization reaction, the shape of the desired three-dimensional model, and the like. This is because non-uniform strain stress is inherent in the obtained three-dimensional molded item. If such strain stress concentrates on a specific portion or in a specific direction in the three-dimensional molded item, warping, twisting, crushing, or other deformation, and further cracking, peeling, or other structural destruction may occur. A three-dimensional object with such a strain stress is potentially inferior in shape accuracy. Therefore, the obtained three-dimensional object is difficult to use for applications that require high shape accuracy, such as creating master models for mold making, and creating design study models and some medical models. Can be used only for limited purposes.

[0005]

The problem to be solved by the present invention is that the conventional optical three-dimensional molding resin has a problem even if it contains unsaturated urethane having a soft segment chain in the molecule. The precision of the shape of the three-dimensional object is poor.

[0006]

However, the present inventors have
Regarding optical three-dimensional modeling resin containing unsaturated urethane, focusing on unsaturated urethane having a soft segment chain in the molecule, the chemical structure of such unsaturated urethane and vinyl monomer used in combination and the obtained three-dimensional modeling product As a result of studying the relationship between shape accuracy, it was found that it is correct and preferable to use unsaturated urethane of a specific structure and a specific vinyl monomer containing (meth) acrylic acid morpholide in respective predetermined ratios. It was

That is, the present invention comprises an unsaturated urethane represented by the following formula 1, formula 2 or formula 3 and the following vinyl monomer, and the unsaturated urethane / the vinyl monomer = 100.
/ 25 to 100/150 (weight ratio).

[0008]

(Equation 1)

[0009]

(Equation 2)

[0010]

(Equation 3)

(In Formulas 1, 2 and 3, Z ¹ is a residue obtained by removing an isocyanate group from urethane diisocyanate or urethane triisocyanate Z ² : A residue obtained by removing an isocyanate group from polyurethane diisocyanate or polyurethane triisocyanate Z ³ : Residues obtained by removing hydroxyl groups from a polyol selected from polyether polyols, polyester polyols and polyether ester polyols, both of which are divalent or trivalent, A ¹ and A ² : both are the same or different at the same time, and are represented by the following formula 4. group a ^3: same or different at the same time, group m of formula 5 below, n, p: 2 or 3)

[0012]

(Equation 4)

[0013]

[Formula 5]

(In equations 4 and 5, R¹, R²: H or CH₃  Y¹: Residue Y obtained by removing a hydroxyl group from a dihydric alcohol Y²: C2-4 alkylene group)

Vinyl monomer: (meth) acrylic acid morpholide or a mixture of (meth) acrylic acid morpholide and diol di (meth) acrylate.

For the unsaturated urethane represented by the formula 1, 1)
Reaction product of mono (meth) acrylate of dihydric alcohol / urethane diisocyanate = 2/1 (molar ratio), 2) 2
A monohydric alcohol mono (meth) acrylate / urethane triisocyanate = 3/1 (molar ratio) reactant is included.

In the present invention, the mono (meth) acrylate of dihydric alcohol means monoacrylate of dihydric alcohol or monomethacrylate of dihydric alcohol. Examples of the mono (meth) acrylate of the dihydric alcohol include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and 1,6-hexanediol mono (meth) acrylate having 2 to 2 carbon atoms.
The mono (meth) acrylate of the dihydric alcohol of 6 is mentioned.

As the urethane diisocyanate or urethane triisocyanate to be reacted with the mono (meth) acrylate of the dihydric alcohol as exemplified above, 1)
1 mol of polyether diol, polyester diol or polyether ester diol and 2 diisocyanates
Examples thereof include urethane diisocyanate which is a urethanization reaction product with 2 mol, and 2) urethane triisocyanate which is a urethanization reaction product with 1 mol of polyether triol, polyester triol or polyether ester triol and 3 mol of diisocyanate.

The above polyether diols having 2 to 6 carbon atoms, such as polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethoxylated 1,4-butanediol, polypropoxylated 1,6-hexanediol and the like. Dihydric alcohol has 2 to 2 carbon atoms
The polyalkoxylated dihydric alcohol obtained by adding the alkylene oxide of 4 is mentioned, but the one in which propylene oxide is added as the alkylene oxide is preferable.

Examples of the above-mentioned polyether triol include polyethoxylated glycerin, polypropoxylated trimethylolpropane, polybutoxylated hexanetriol, and the like, and C3 to C6 trihydric alcohol to C2 to C4 alkylene oxide. Examples thereof include polyalkoxylated trihydric alcohols obtained by adding propylene oxide, and those having propylene oxide added as an alkylene oxide are preferable.

Further, as the above-mentioned polyester diol and polyester triol, an aliphatic lactone or an aliphatic oxycarboxylic acid having 4 to 6 carbon atoms is added to the dihydric alcohol or the trihydric alcohol used in the synthesis of the polyether diol or the polyether triol. Examples thereof include those obtained by the reaction, and those obtained by reacting ε-caprolactone as the aliphatic lactone and those obtained by reacting oxypivalic acid as the aliphatic oxycarboxylic acid are preferable.

Examples of the above-mentioned polyether ester diol and polyether ester triol include those obtained by reacting the above-mentioned polyether diol or polyether triol with the above-mentioned aliphatic lactone or aliphatic oxycarboxylic acid.

As the diisocyanate to be reacted with the polyether diol, polyether triol, polyester diol or polyester triol as exemplified above, 1) various tolylene diisocyanates, methylene-bis- (4-phenylisocyanate) and other aromatic compounds Diisocyanate, 2) Aliphatic diisocyanate or alicyclic diisocyanate such as hexamethylene diisocyanate and methylenebis (4-cyclohexyl isocyanate), 3) 4-isocyanatomethyl-1-isocyanato-1-methyl-cyclohexane, 5-isocyanatomethyl- 1-isocyanato-1,1-dimethyl-5-methyl-cyclohexane (isophorone diisocyanate)
Aliphatic / alicyclic diisocyanates such as

For the unsaturated urethane represented by the formula 2, 1)
Reaction product of mono (meth) acrylate of dihydric alcohol / polyurethane diisocyanate = 2/1 (molar ratio),
2) The reaction product of mono (meth) acrylate of dihydric alcohol / polyurethane triisocyanate = 3/1 (molar ratio) is included.

In the present invention, the polyurethane diisocyanate is defined by n moles of diol and diisocyanate (n + 1).
It is a polyurethane having free isocyanate groups at both ends, which is obtained by a urethanization reaction with moles. Here, as the diol, 1) alkane diol having 2 to 12 carbon atoms, 2) the above-mentioned polyether diol, polyester diol, polyether ester diol, 3)
These mixtures are mentioned.

In the present invention, the polyurethane triisocyanate is obtained by the urethanization reaction of 3 mol of the above-mentioned urethane diisocyanate or polyurethane diisocyanate and 1 mol of triol, and is a polyurethane having 3 isocyanate groups as terminal groups. . Here, as a triol, 1) 3 to 3 carbon atoms
12 alkane triols, 2) the above-mentioned polyether triols, polyester triols, polyether ester triols, 3) mixtures thereof.

Examples of the mono (meth) acrylate of the dihydric alcohol used for the synthesis of the unsaturated urethane represented by the formula 2 include those exemplified in the case of the unsaturated urethane of the formula 1.

The unsaturated urethane represented by the formula 3 is a urethanization reaction product of a polyol and a (meth) acryloyloxyalkyl isocyanate, and includes 1) diol / (meth) acryloyloxyalkyl isocyanate = 1/2. (Molar ratio) of reactants, 2) triol /
(Meth) acryloyloxyalkyl isocyanate =
1/3 (molar ratio) of reactants are included.

As the polyols, the diols and triols exemplified in the synthesis of the above-mentioned urethane diisocyanate and urethane triisocyanate can be used.

The (meth) acryloyloxyalkylisocyanate to be reacted with the polyol is a (meth) acryloyloxyalkylisocyanate whose alkyl group has 2 to 4 carbon atoms. Examples of such (meth) acryloyloxyalkyl isocyanate include acryloyloxyethyl isocyanate and acryloyloxy-2-
Examples thereof include methyl-ethyl isocyanate, methacryloyloxyethyl isocyanate, methacryloyloxy-2-methyl-ethyl isocyanate, and of these, methacryloyloxyethyl isocyanate and acryloyloxyethyl isocyanate can be advantageously used.

The present invention does not particularly limit the method for synthesizing unsaturated urethane, and a known method, for example, the method described in JP-A-4-53809 can be applied to the synthesis.

According to the present invention, the unsaturated urethane represented by the formula 1, the formula 2 or the formula 3 preferably has m, n or p of 3, and in this case, the number of the polymerizable groups contained in the molecule. There will be three, but among such unsaturated urethanes,
Particularly preferred are those in which at least two of the three polymerizable groups are acryloyl groups.

According to the present invention, the formula 1, the formula 2, or the formula 3 is also used.
In the unsaturated urethane represented by, those having a molecular weight of 400 to 1000 per one polymerizable group contained in the molecule are preferable.

The resin for optical three-dimensional modeling of the present invention has the formula 1,
It is composed of an unsaturated urethane represented by Formula 2 or Formula 3 and a vinyl monomer, and the vinyl monomer is (meth)
It is composed of a single system of acrylic acid morpholide or a mixed system of (meth) acrylic acid morpholide and diol di (meth) acrylate.

As (meth) acrylic acid morpholide,
Acrylic acid morpholide and methacrylic acid morpholide are mentioned, but acrylic acid morpholide is preferable.

The diol di (meth) acrylate used when mixed with (meth) acrylic acid morpholide is 1) ethylene glycol, propylene glycol,
1,4-butanediol, neopentyl glycol,
A diacrylate or dimethacrylate of an alkanediol having 2 to 6 carbon atoms such as 1,6-hexanediol,
2) Diacrylates or dimethacrylates of diols having an alicyclic hydrocarbon group having 6 to 12 carbon atoms such as cyclohexanedimethanol, cyclohexene dimethanol, dicyclopentyl dimethanol, and 3) Alkane diols and diols described above. Obtained by reacting an aliphatic lactone or an aliphatic oxycarboxylic acid having 4 to 6 carbon atoms,
Diacrylates or dimethacrylates of (poly) ester diols, such as diacrylates or dimethacrylates of neopentyl glycol hydroxypivalate, diacrylates or dimethacrylates of 1,6-hexanediol hydroxycaprate, 4) 2,2-bis Alkoxyl group having 2 to 3 carbon atoms such as (hydroxyethoxyphenyl) propane, 2,2-bis (hydroxydiethoxyphenyl) propane, bis (hydroxypropoxyphenyl) methane and bis (hydroxydipropoxyphenyl) methane. Examples thereof include bisphenol diacrylate or dimethacrylate.

In the present invention, when a mixed system of (meth) acrylic acid morpholide and diol di (meth) acrylate is used as the vinyl monomer, (meth) acrylic acid morpholide is contained in the vinyl monomer in an amount of 50% by weight or more. The content is preferably contained in a proportion, and more preferably 60% by weight or more.

In the resin for optical three-dimensional modeling of the present invention,
The ratio of the unsaturated urethane and the vinyl monomer is such that the unsaturated urethane / the vinyl monomer = 100/25 to 100/15
0 (weight ratio), preferably 100/40 to 100
/ 100 (weight ratio).

The resin for optical three-dimensional modeling of the present invention can appropriately contain fillers such as solid fine particles and inorganic fiber whiskers, if necessary. When using solid fine particles as the filler, those having an average particle diameter of 100 μm or less are preferable, and when using inorganic fiber whiskers as the filler, those having a fiber diameter of 0.3 to 1 μm and an average fiber length of 100 μm or less are preferable. . Examples of such fillers are 1) inorganic solid fine particles such as silica, alumina, clay, calcium carbonate and glass beads, 2) organic solid fine particles such as crosslinked polystyrene, polymethylmethacrylate and polymethylsiloxane, 3) potassium titanate fiber, sulfuric acid. Inorganic fiber whiskers such as magnesium fiber and carbon fiber can be used.

When the resin for optical three-dimensional modeling of the present invention is subjected to optical three-dimensional modeling, a photopolymerization initiator is added to them in advance. The present invention does not particularly limit the type of photopolymerization initiator used, but as such a photopolymerization initiator,
1) carbonyl compounds such as benzoin, α-methylbenzoin, anthraquinone, chloranthraquinone and acetophenone, 2) sulfur compounds such as diphenyl sulfide, diphenyl disulfide and dithiocarbamate,
3) Polycyclic aromatic compounds such as α-chloromethylnaphthalene and anthracene are listed. The content of the photopolymerization initiator in the resin for optical three-dimensional modeling is usually 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the resin for optical three-dimensional modeling. To do so. A photosensitizer such as n-butylamine, triethanolamine, N, N-dimethylaminobenzenesulfonic acid diallylamide, or N, N-dimethylaminoethyl methacrylate can be used together with the photopolymerization initiator.

The present invention does not particularly limit the optical three-dimensional modeling method to which the resin for optical three-dimensional modeling of the present invention is applied. Various methods are known as such an optical three-dimensional modeling method (JP-A-56-144478, JP-A-60-2).
47515, JP-A-1-204915, JP-A-3-41.
126 etc.), for example, first, a cured layer of an optical three-dimensional modeling resin is first formed, and then a new optical three-dimensional modeling resin is supplied on the cured layer to form the cured layer. There is a method of repeating the above operation to form a desired three-dimensional object. This three-dimensional object can be further post-cured if necessary. Examples of energy rays used for curing include visible rays, ultraviolet rays, and electron rays, and ultraviolet rays are preferable.

Hereinafter, the constitution and effects of the present invention will be more specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following Examples and Comparative Examples, parts mean parts by weight and% means% by weight unless otherwise specified.

[0043]

【Example】

Test Category 1 (Preparation of Resin for Optical Stereoscopic Modeling) Examples 1 to 11 and Comparative Examples 1 to 8 Unsaturated urethane A-1 {glycerin caprolactone (according to the synthesis method described in JP-A-2-73817) 8 mol) adduct / isophorone diisocyanate = 1
A reaction product of / 3 (molar ratio) and hydroxyethyl acrylate reacted at a molar ratio of 1/3} was synthesized.
100 parts of the synthesized unsaturated urethane A-1 and 100 parts of acrylic acid morpholide were mixed and dissolved at room temperature to give Example 1.
The resin for optical three-dimensional modeling of was prepared. In the same manner as in Example 1, the resins for optical stereolithography of Examples 2-9 and Comparative Examples 1-8 were prepared. These compositions are summarized in Table 1.

[0044]

[Table 1]

In Table 1, A-1: reactant of GCL-8-3I / hydroxyethyl acrylate = 1/3 (molar ratio) A-2: GCL-8-3I / hydroxyethyl acrylate / hydroxyethyl methacrylate = 1 / 2/1
Reaction product (molar ratio) A-3: GPO-6-3T / hydroxyethyl acrylate = 1/3 (molar ratio) reaction product A-4: TMPPV-3-3T / hydroxyethyl acrylate = 1/3 (mol) Reaction of A-5: G-PCL-TDI / hydroxyethyl acrylate = 1/3 (molar ratio) reaction of A-6: PPG-TDI / hydroxyethyl acrylate = 1/2 (molar ratio) Product A-7: Glycerin propylene oxide (15 mol)
Adduct / Acryloyloxyethyl isocyanate = 1
/ 3 (molar ratio) of the reaction product (however, GCL-8-3I; glycerin caprolactone (8 mol) adduct / isophorone diisocyanate = 1/3 (molar ratio) of the reaction product urethane triisocyanate GPO-6-3T) Glycerin propylene oxide (6 mol) adduct / 2,4-tolylene diisocyanate = 1/3 (molar ratio), urethane triisocyanate TMPPV-3-3T; trimethylolpropane hydroxypivalate (3 mol) Urethane triisocyanate which is a reaction product of adduct / 2,4-tolylene diisocyanate = 1/3 (molar ratio) G-PCL-TDI; glycerin / polycaprolactone (4 mol) diol / 2,4-tolylene diisocyanate = Urethane triisocyanate which is a reaction product of 1/3/6 (molar ratio) T PPG-TDI; Polyoxypropylene glycol (average molecular weight 200) / 2,4-tolylene diisocyanate = polyurethane diisocyanate which is a reaction product of 3/4 (molar ratio)} B-1: acrylic acid morpholide B-2: methacryl Acid morpholide C-1: neopentyl glycol diacrylate C-2: dicyclopentyl dimethylene diacrylate C-3: neopentyl glycol hydroxypivalate diacrylate

Test Category 2 (Production of 3D object and its evaluation) 1) Preparation of 3D object Mainly composed of a three-dimensional NC table equipped with a container and a helium / cadmium laser light (output 25 mW, wavelength 3250 angstrom) control system. The constructed optical three-dimensional modeling apparatus was used. The above-mentioned container was filled with one in which 3 parts of 1-hydroxycyclohexyl phenyl ketone was dissolved as a photopolymerization catalyst per 100 parts of the optical three-dimensional modeling resin prepared in Test Category 1 (hereinafter, simply referred to as a mixed solution), The mixed solution was supplied from the container to a horizontal plane (XY axis plane) with a thickness of 0.10 mm, and helium was focused from a direction (Z axis direction) perpendicular to the surface (XY axis plane). -The cadmium laser beam was scanned to cure the resin for optical three-dimensional modeling. Next, a new mixed liquid having a thickness of 0.10 mm was supplied onto the cured product and cured in the same manner. Thereafter, in the same manner, a total of 200 layers were laminated to form a conical solid body having a design value of a bottom surface diameter of 200.00 mm and a height of 20.00 mm. The obtained modeled product was washed with isopropyl alcohol and then irradiated with a 3 Kw ultraviolet lamp for 30 minutes to perform post-curing to obtain a three-dimensional modeled product.

2) Measurement of shape Regarding the three-dimensional object obtained in 1), 2 on the XY axis plane.
The two-dimensional figure a was vertically projected, and the two-dimensional figure b was horizontally projected on 50 arbitrary planes perpendicular to the X-Y axis plane, and the following measurements were performed on these projections. The results are shown in Table 2. The two-dimensional figure a obtained here is a circle, and the two-dimensional figure b is a triangle. Two-dimensional figure a: Draw 50 arbitrary straight lines passing through the center of gravity of the projected view, measure the distance between two points intersecting the contour of the projected view,
For these measured values, the average value, maximum value, minimum value and standard deviation were calculated. Two-dimensional figure b: The area of 50 projection views was measured, and the average value, maximum value, minimum value and standard deviation were calculated for these measured values.

[0048]

[Table 2]

[0049]

As is apparent from the above, the present invention described above has an effect that it is possible to obtain a three-dimensional object having excellent shape accuracy.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B29K 101: 00

Claims (4)

[Claims] 1. An unsaturated urethane represented by the following formula 1, formula 2 or formula 3 and the following vinyl monomer, wherein the unsaturated urethane / the vinyl monomer = 100/25 to 100 /
A resin for optical three-dimensional modeling, which is characterized by comprising a ratio of 150 (weight ratio). (Equation 1) (Equation 2) (Equation 3) (In Formulas 1, 2 and 3, Z ¹ is a residue obtained by removing an isocyanate group from urethane diisocyanate or urethane triisocyanate Z ² : A residue obtained by removing an isocyanate group from polyurethane diisocyanate or polyurethane triisocyanate Z ³ : Any Residues A ¹ and A ^{2 obtained} by removing a hydroxyl group from a polyol selected from di- or trivalent polyether polyols, polyester polyols and polyether ester polyols: the same or different at the same time, a group A ^{3 represented} by the following formula 4 : The same or different groups represented by the following formula 5 at the same time m, n, p: 2 or 3) [Formula 4] [Formula 5] (In Formula 4 and Formula 5, R ¹ , R ² : H or CH ₃ Y ¹ : a residue obtained by removing a hydroxyl group from a dihydric alcohol Y ² : an alkylene group having 2 to 4 carbon atoms) Vinyl monomer: (meta ) A mixture of acrylic acid morpholide or (meth) acrylic acid morpholide and diol di (meth) acrylate 2. The unsaturated urethane represented by formula 1, formula 2 or formula 3 has three polymerizable groups in the molecule,
The resin for optical stereolithography according to claim 1, wherein at least two of the polymerizable groups are acryloyl groups. 3. The resin for optical stereolithography according to claim 1, wherein the vinyl monomer contains 50% by weight or more of (meth) acrylic acid morpholide. 4. A diol di (meth) acrylate is a di (meth) acrylate of an alkanediol having 2 to 6 carbon atoms, a di (meth) acrylate of a diol having an alicyclic hydrocarbon group having 6 to 12 carbon atoms, A di (meth) acrylate of an ester diol obtained by reacting an alkanediol having 2 to 6 carbon atoms with an oxycarboxylic acid having 4 to 6 carbon atoms and a di (meth) alkoxylated bisphenol having 2 to 3 carbon atoms in an alkoxyl group. ) The resin for optical stereolithography according to claim 1, 2 or 3, which is one or more selected from acrylates.