JP2017031318A - Polythiol compound, curable composition and cured article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polythiol compound capable of being a raw material for a curable composition and introducing a carbonate skeleton to a cured article.SOLUTION: A polythiol compound is an ester compound of a hydroxyl group of polycarbonate polyol (A) which is polycarbonate having a plurality of hydroxy groups and a carboxyl group of a mercapto group-containing carboxylic acid (B) represented by the following chemical formula (I) and has a plurality of mercapto groups in a molecule. Rin the following chemical formula (I) represents a branched alkylene group having 2 to 10 carbon atoms.SELECTED DRAWING: None

Description

  The present invention relates to a polythiol compound, a curable composition, and a cured product.

  Polycarbonate resin is a thermoplastic resin used as a matrix resin for composite materials such as fiber reinforced plastics, but has a relatively high melt viscosity and low fluidity. As a method for incorporating a carbonate skeleton into the matrix resin and making the melt viscosity relatively low, there is a method in which a polycarbonate diol and a polyisocyanate are reacted to form a polycarbonate polyurethane (see, for example, Non-Patent Document 1).

  However, since polyisocyanate is a hard segment, there is a problem that flexibility is lowered and the excellent flexibility inherent in polycarbonate resin may not be obtained. Moreover, since the isocyanate compound generally has a strong odor and high toxicity, its use may be limited. Furthermore, in order to react the polycarbonate diol with the polyisocyanate, it is necessary to add a chain extender, a chain terminator, a catalyst, etc., and control the temperature to a high temperature. It was necessary to carry out processing after reacting to form polyurethane. Therefore, it has not been possible to adopt a method of reacting raw materials to form polyurethane during processing steps such as molding and coating.

Fine Chemical February 2009, Vol. 38, no. 2, CMC Publishing

  Therefore, the present invention solves the problems of the prior art as described above, can produce a cured product having excellent flexibility, has a low odor and has an appropriate pot life, It is an object of the present invention to provide a curable composition that can be cured during processing steps such as molding and coating. Another object of the present invention is to provide a cured product having excellent flexibility. Furthermore, this invention makes it a subject to provide the polythiol compound which can become a raw material of the said curable composition and can introduce | transduce carbonate frame | skeleton into hardened | cured material.

In order to solve the above problems, one embodiment of the present invention is as described in [1] to [7] below.
[1] An esterified product of the hydroxy group of the polycarbonate polyol (A), which is a polycarbonate having a plurality of hydroxy groups, and the carboxy group of the mercapto group-containing carboxylic acid (B) represented by the following chemical formula (I), A polythiol compound having a plurality of mercapto groups in the molecule.
However, R ¹ in the following chemical formula (I) represents a branched alkylene group having 2 to 10 carbon atoms.

[2] The polythiol compound according to [1], wherein the mercapto group-containing carboxylic acid (B) is at least one of a compound represented by the following chemical formula (II) and a compound represented by the following chemical formula (III).

[3] The polythiol compound according to [1] or [2], wherein the polycarbonate polyol (A) has a weight average molecular weight of 400 or more and 5000 or less.
[4] The polycarbonate polyol (A) is selected from 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,6-hexanediol, and 1,9-nonanediol. The polythiol compound according to any one of [1] to [3], which has a structure derived from at least one diol component.
[5] A curable composition containing the polythiol compound according to any one of [1] to [4] and an epoxy compound having two or more epoxy groups.
[6] A curable composition containing the polythiol compound according to any one of [1] to [4], a photopolymerizable compound, and a photopolymerization initiator.
[7] A cured product of the curable composition according to [5] or [6].

The curable composition of the present invention can produce a cured product having excellent flexibility, has a low odor, has an appropriate pot life, and further cures during processing steps such as molding and coating. It can be carried out.
The cured product of the present invention has excellent flexibility.
Furthermore, the polythiol compound of the present invention can be a raw material for the curable composition, and can introduce a carbonate skeleton into the cured product.

2 is a ¹ H-NMR chart of a polythiol compound of Synthesis Example 1. FIG. 2 is a ¹ H-NMR chart of a polythiol compound of Synthesis Example 2. 2 is a ¹ H-NMR chart of a polythiol compound of Synthesis Example 3. 6 is a ¹ H-NMR chart of a polythiol compound of Synthesis Example 4. 6 is a ¹ H-NMR chart of a polythiol compound of Synthesis Example 5. 6 is a ¹ H-NMR chart of a polythiol compound of Synthesis Example 6. 4 is an FT-IR chart of the polythiol compound of Synthesis Example 1. 4 is an FT-IR chart of the polythiol compound of Synthesis Example 2. 6 is an FT-IR chart of the polythiol compound of Synthesis Example 3. 6 is an FT-IR chart of the polythiol compound of Synthesis Example 4. 6 is an FT-IR chart of the polythiol compound of Synthesis Example 5. 14 is an FT-IR chart of the polythiol compound of Synthesis Example 6.

As a result of intensive studies to solve the problems of the above-described conventional techniques, the present inventors have found that the above problems can be solved by using a polythiol compound having a polycarbonate skeleton, and have completed the present invention. It was.
That is, the polythiol compound of the present invention includes the hydroxy group of the polycarbonate polyol (A), which is a polycarbonate having a plurality of hydroxy groups, and the carboxy group of the mercapto group-containing carboxylic acid (B) represented by the following chemical formula (I). Esterified product having a plurality of mercapto groups in the molecule.
However, R ¹ in the following chemical formula (I) represents a branched alkylene group having 2 to 10 carbon atoms.

  This polythiol compound can be a raw material of the curable composition, and can introduce a polycarbonate skeleton into the cured product. Since this polythiol compound has a low odor, the curable composition containing the polythiol compound and the cured product thereof can have a low odor. Moreover, since this polythiol compound has a polycarbonate skeleton, the cured product of the curable composition containing this polythiol compound has excellent flexibility. Furthermore, since this polythiol compound has a polycarbonate skeleton, the curable composition containing this polythiol compound has an appropriate pot life. Furthermore, the curable composition containing this polythiol compound can be cured during processing steps such as molding and coating. Therefore, the curable composition and the cured product can be applied to various industrial fields such as paints, adhesives, resists and flooring.

Below, the polythiol compound, curable composition, and hardened | cured material which concern on one Embodiment of this invention are demonstrated in detail.
1. About Polythiol Compound <(1-1) Polycarbonate Polyol (A)>
The polycarbonate polyol (A) is a polycarbonate having a plurality of hydroxy groups in the molecule (for example, a polycarbonate having one hydroxy group at each of both ends). Since it is important for the solution of the subject of this invention that a polycarbonate polyol (A) becomes a crosslinking point of hardened | cured material, it is necessary to have a some hydroxy group in a molecule | numerator.

Examples of the polycarbonate polyol (A) include polypropylene carbonate diol, polybutylene carbonate diol, polyhexamethylene carbonate diol, polyoctamethylene carbonate diol, polycyclohexane dimethanol carbonate diol, and the like.
Among them, the diol component when producing the polycarbonate polyol (A) is 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,6-hexanediol, and 1,9- It is preferably at least one selected from nonanediol, and more preferably includes both 3-methyl-1,5-pentanediol and 1,6-hexanediol. That is, the polycarbonate polyol (A) preferably has a structure derived from the above diol component.
As a commercially available polycarbonate polyol, Kuraray Polyol C series manufactured by Kuraray Co., Ltd. can be used. In addition, you may use multiple types of polycarbonate polyol together as a polycarbonate polyol (A).

  The weight average molecular weight of the polycarbonate polyol (A) may be 400 or more and 5000 or less, and more preferably 500 or more and 3000 or less. If the weight average molecular weight is 400 or more, the boiling point becomes high, so that the polycarbonate polyol (A) is hardly volatilized during the esterification reaction with the mercapto group-containing carboxylic acid (B), and the reaction control becomes easy. Moreover, since the thiol equivalent is 200 or more, the curable composition containing the polythiol compound synthesized from the polycarbonate polyol (A) has a sufficiently long pot life. Furthermore, when the curable composition containing the polythiol compound synthesized from the polycarbonate polyol (A) is used as a cured product, the distance between the cross-linking points is increased, so that the cured product has excellent flexibility.

  On the other hand, if the weight average molecular weight is 5,000 or less, the polycarbonate polyol (A) is less likely to be waxy at room temperature, which is excellent in handling and advantageous in terms of cost. Moreover, the curable composition containing the polythiol compound synthesized from the polycarbonate polyol (A) hardly causes curing failure. Here, the weight average molecular weight is a polystyrene equivalent weight average molecular weight measured by gel permeation chromatography.

<(1-2) Mercapto group-containing carboxylic acid (B)>
The mercapto group-containing carboxylic acid (B) is a compound having a mercapto group and a carboxy group in the molecule as shown in the chemical formula (I). R ¹ in the chemical formula (I) has 2 to 10 carbon atoms. It is preferably the following branched alkylene group, which is a branched alkylene group having 2 to 10 carbon atoms in which the α-position and / or β-position carbon atom of the mercapto group has an alkyl group as a substituent. .

  The mercapto group-containing carboxylic acid (B) is more preferably at least one of a compound represented by the following chemical formula (II) and a compound represented by the following chemical formula (III).

If R ¹ is a branched alkylene group in which the α-position carbon atom of the mercapto group has an alkyl group as a substituent, as in the compounds represented by chemical formulas (II) and (III), The polythiol compound which is an esterified product synthesized from the carboxylic acid (B) and the polycarbonate polyol (A) has a low odor.

  Specific examples of the mercapto group-containing carboxylic acid (B) include 2-mercaptopropionic acid, 3-mercaptobutanoic acid, 2-mercaptoisobutanoic acid, 3-mercapto-3-phenylpropionic acid, 3-mercaptoisobutyric acid, 2- Examples include mercapto-3-methylbutyric acid, 3-mercapto-3-methylbutyric acid, 3-mercaptovaleric acid, 3-mercapto-4-methylvaleric acid and the like.

<(1-3) Production method of polythiol compound>
The method for producing the thiol compound of the present embodiment is particularly limited as long as it is a method capable of esterifying the hydroxy group of the polycarbonate polyol (A) and the carboxy group of the mercapto group-containing carboxylic acid (B). is not. A polythiol compound can be obtained by reacting the polycarbonate polyol (A) and the mercapto group-containing carboxylic acid (B) by a conventional method to produce an esterified product.

The esterification reaction conditions are not particularly limited, but the esterification reaction temperature is preferably 60 ° C. or higher and 160 ° C. or lower, and more preferably 60 ° C. or higher and 135 ° C. or lower in order to suppress by-products.
When a Dean-Stark apparatus is used for dehydration from the reaction system in the esterification reaction, a more transparent target product can be obtained.

  In the esterification reaction, a solvent may or may not be used, but from the viewpoint of improving the reaction rate, a solvent azeotropic with water is preferably used as the solvent. Examples of the solvent azeotropic with water include toluene, xylene, cyclohexane, and ethylbenzene. Toluene is preferable from the viewpoint of the balance between the manufacturing cost and the obtained effect. The usage-amount of the solvent azeotroped with water can be 10 mass% or more and 90 mass% or less of the whole solvent.

  Regarding the blending amount of the polycarbonate polyol (A) and the mercapto group-containing carboxylic acid (B), the ratio of the number of carboxy groups in the mercapto group-containing carboxylic acid (B) to the number of hydroxy groups in the polycarbonate polyol (A) is 1.0. It is preferable to blend so as to be 4.0 or less. When the ratio of the numbers is 1.0 or more, the remaining of unreacted hydroxy groups can be suppressed, and the number of mercapto groups in one molecule of the polythiol compound is 2 or more. The curability of the product is improved. Moreover, a manufacturing cost can be suppressed as the ratio of the said number is 4.0 or less.

  The reaction pressure of the esterification reaction is not particularly limited, but it is preferably 13.3 kPa (100 mmHg) or more and 101.3 kPa (760 mmHg) or less from the viewpoint of improving the reaction rate, and 40 kPa from the viewpoint of dehydration efficiency. (300 mmHg) or more and 73.3 kPa (550 mmHg) or less is more preferable. If the reaction pressure is within the above range, the temperature in the reaction system becomes high, and the esterification reaction easily proceeds.

  A catalyst may be used for the esterification reaction of the polycarbonate polyol (A) and the mercapto group-containing carboxylic acid (B). As the catalyst, a non-volatile acid catalyst is preferable, and specific examples include inorganic acids such as sulfuric acid, perchloric acid, and phosphoric acid, and solid acid catalysts such as p-toluenesulfonic acid, methanesulfonic acid, and levulinic acid. However, non-volatile strong acids such as p-toluenesulfonic acid, methanesulfonic acid, and sulfuric acid are more preferable from the viewpoint of reaction rate.

  In addition, a non-volatile acid catalyst means the acid catalyst whose vapor pressure in 25 degreeC is 1 kPa or less. The usage-amount of a catalyst can be 0.01 mol or more and 1.0 mol or less with respect to 1 mol of hydroxy groups of a polycarbonate polyol (A). If the amount of catalyst used is not less than the above lower limit value, a sufficient reaction rate can be obtained, and if it is not more than the above upper limit value, many basic substances are required for the neutralization treatment of the catalyst after completion of the esterification reaction. Instead, the cost of treating industrial waste can be reduced.

  After completion of the esterification reaction, the remaining acid catalyst may be neutralized. The basic substance for neutralization is not particularly limited, but sodium bicarbonate and sodium hydroxide are preferable from the viewpoint of cost reduction, and sodium bicarbonate is more preferable from the viewpoint of ease of pH adjustment. preferable.

The completion of the esterification reaction can be determined by the amount of water extracted from the reaction system using a Dean-Stark apparatus or the like. It is preferable to carry out the reaction until the amount of water extracted from the reaction system reaches the theoretical value of the dehydration amount by the esterification reaction. However, when the reaction takes a long time, 80% by mass or more of the theoretical amount of water is extracted. The reaction can be terminated at the stage where it is released.
When the extracted water amount is 80% by mass or more of the theoretical value of the dehydration amount by the esterification reaction, since there are few unreacted hydroxy groups, when the polythiol compound of this embodiment is added to the curable composition, The curability of the curable composition is improved.

  Moreover, after completion | finish of esterification reaction, you may extract a polythiol compound from the inside of a reaction system from a viewpoint of refine | purifying a target object. As the extraction solvent for extraction, toluene, ethyl acetate, isopropyl acetate, and butyl acetate are preferable from the viewpoint of easiness of volatilization, and toluene and ethyl acetate are more preferable from the viewpoint of the cost of the extraction solvent. In addition, a hydrophobic solvent may be added to the extraction solvent for the purpose of improving the separation speed of the extraction solvent from water during extraction, from the viewpoint of the separation speed and the cost of the hydrophobic solvent. , Hexane and heptane are more preferable.

  When a solvent is used for the esterification reaction, a mixture of the polythiol compound and the solvent is obtained. Therefore, the solvent may be removed from the mixture after the esterification reaction is completed. The removal of the solvent can be carried out, for example, by distilling off the solvent under heating and reduced pressure conditions. The distillation temperature is preferably 80 ° C. or higher and 150 ° C. or lower regardless of the degree of pressure reduction. If it is 80 degreeC or more, a solvent can be distilled off completely, and if it is 150 degreeC or less, superposition | polymerization of the synthesized polythiol compounds can be prevented.

  When the viscosity of the obtained polythiol compound is high, a solvent may be mixed with the polythiol compound to adjust the viscosity to a desired value. The type of solvent that can be used is not particularly limited, but toluene, acetone, methanol, ethanol, methyl ethyl ketone, ethyl acetate, isopropyl acetate, and butyl acetate are preferred because of the volatility of the solvent and the solubility of the polythiol compound. .

2. About curable composition If the polythiol compound of this embodiment and resin, such as an epoxy resin and an acrylic resin, are mixed, various curable compositions can be prepared. Since these curable compositions have an appropriate pot life, processing such as molding and coating can be performed by a safe curing operation such as thermal curing and photocuring. Various curable compositions will be described below.

<(2-1) Epoxy composition>
Since the polythiol compound of this embodiment has a mercapto group, it can be used as an epoxy curing agent. If the polythiol compound of this embodiment and the epoxy compound which has 2 or more of epoxy groups in a molecule | numerator are mixed, the epoxy composition which is a curable composition can be obtained. A polythiol compound may be used individually by 1 type, and may use 2 or more types together. Moreover, similarly about an epoxy compound, 1 type may be used independently and 2 or more types may be used together. Furthermore, you may add various additives, such as an epoxy hardening accelerator, to an epoxy composition.

  The type of epoxy compound is not particularly limited, but specific examples include bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F type epoxy resin, and novolak type epoxy. Resin, phenol novolac epoxy resin, cresol novolac epoxy resin, alicyclic epoxy resin, N-glycidyl epoxy resin, bisphenol A novolac epoxy resin, chelate epoxy resin, glyoxal epoxy resin, amino group-containing epoxy resin Rubber-modified epoxy resin, caprolactone-modified epoxy resin, dicyclopentadiene type epoxy resin and the like.

  Examples of the commercially available epoxy compounds (polyvalent epoxy compound products) include, for example, jER (registered trademark) 828, 1001, 801, 806, 807, 152, 604, 630, 871, YX8000, manufactured by Mitsubishi Chemical Corporation. YX8034, YX4000, Cardura E10P manufactured by Japan Chemtech Co., Ltd., Epicron (registered trademark) 830, 835LV, HP4032D, 703, 720, 726, HP820 manufactured by Dainippon Ink & Chemicals, Inc. EP4100, EP4000, EP4080, EP4085, EP4088, EPU6, EPR4023, EPR1309, EP49-20, Denasel EX411, EX314, EX201, EX212, EX252, E manufactured by Nagase ChemteX Corporation 111, can be exemplified EX146, EX721 like.

  The epoxy composition of this embodiment can improve the heat resistance, adhesiveness, chemical resistance, and the like of the cured product by containing an epoxy curing accelerator as necessary. The type of epoxy curing accelerator is not particularly limited, and examples thereof include amine curing accelerators, guanidine curing accelerators, imidazole curing accelerators, and phosphonium curing accelerators. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Specific examples of the amine curing accelerator include trialkylamine (triethylamine, tributylamine, etc.), 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8- Examples include amine compounds such as diazabicyclo (5,4,0) -undecene and 1,5-diazabicyclo (4,3,0) -nonene. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Specific examples of the guanidine curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine. , Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0 ] Deca-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1-dimethyl biguanide, 1,1-diethyl biguanide, 1-cyclohexyl biguanide, 1-allyl biguanide, 1-phenyl biguanide, 1- ( - tolyl) biguanide, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Specific examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2 -Phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2 -Ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- 6- [2 -Methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino- 6- [2′-Ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s -Triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, - phenyl imidazoline, 1- (2-hydroxy) -3-phenoxy-2- imidazole compounds of methylimidazole and imidazole compounds and adducts with epoxy resins. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Specific examples of phosphonium curing accelerators include tetraphenylphosphonium bromide, tetrabutylphosphonium bromide, butyltriphenylphosphonium bromide, tetraphenylphosphonium iodide, tetrabutylphosphonium iodide, butyltriphenylphosphonium iodide, tetraphenylphosphonium tetra Phenyl borate, tetrabutylphosphonium tetraphenylborate, butyltriphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrabutylborate, tetrabutylphosphonium tetrabutylborate, butyltriphenylphosphonium tetrabutylborate, tetraphenylphosphonium acetate, tetrabutylphosphonium acetate, Butyltriphenylphos Tetraalkylphosphonium acetate, tetrabutylphosphonium tetrafluoroborate, tetrabutyl phosphonium hexafluorophosphate, methyl tributyl phosphonium dimethyl phosphate, tetrabutylphosphonium acetate, tetrabutylphosphonium hydroxide, and the like.

  From the viewpoint of reactivity and transparency, tetrabutylphosphonium bromide, methyltributylphosphonium dimethyl phosphate, tetrabutylphosphonium chloride, tetrabutylphosphonium iodide, tetrabutylphosphonium tetraphenylborate, tetraphenylphosphonium bromide, tetraphenylphosphonium chloride, tetraphenyl Phosphonium iodide and tetraphenylphosphonium tetraphenylborate are preferred, and methyltributylphosphonium dimethyl phosphate and tetrabutylphosphonium bromide are more preferred. These may be used individually by 1 type and may be used in combination of 2 or more type.

The blending ratio of the polythiol compound and the epoxy compound of the present embodiment may be 10 parts by mass or more and 800 parts by mass or less, more preferably 20 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the epoxy compound. is there.
If the blending ratio of the polythiol compound is 10 parts by mass or more, the effect of blending the polythiol compound can be obtained. On the other hand, if the blending ratio of the polythiol compound is 800 parts by mass or less, the crosslinking density in the cured product of the epoxy composition is suitable, and sufficient strength is imparted to the cured product.

Although an epoxy curing accelerator may be blended in the epoxy composition as desired, the blending ratio in that case is 0.05 to 20 parts by mass of the epoxy curing accelerator with respect to 100 parts by mass of the epoxy compound. More preferably, it is 0.1 to 10 parts by mass.
When the blending ratio of the epoxy curing accelerator is 0.05 parts by mass or more, mercaptide ions of the polythiol compound are sufficiently generated. On the other hand, if the compounding ratio of the epoxy curing accelerator is 20 parts by mass or less, the pot life of the epoxy composition is appropriate, and the handling of the epoxy composition becomes easy.

  The curing temperature of the epoxy composition of the present embodiment is not particularly limited, and the curing of the epoxy composition is, for example, any temperature condition of a normal temperature of 5 ° C. or higher and 40 ° C. or lower, and a high temperature higher than 40 ° C. and lower than 200 ° C. It can also be done below. The higher the temperature, the shorter the pot life of the epoxy composition and the faster the curing speed, so that a cured product of the epoxy composition can be obtained in a short time.

<(2-2) Photopolymerizable composition>
Since the polythiol compound of this embodiment has a mercapto group, it can be used as a photocuring accelerator or a photocurable crosslinking agent. If the polythiol compound of this embodiment, a photopolymerizable compound, and a photoinitiator are mixed, the photopolymerizable composition which is a curable composition can be obtained. A polythiol compound may be used individually by 1 type, and may use 2 or more types together. Similarly, the photopolymerizable compound and the photopolymerization initiator may be used alone or in combination of two or more. Furthermore, various additives may be added to the photopolymerizable composition as desired.

Although the kind of photopolymerizable compound is not particularly limited, a compound having an ethylenically unsaturated bond can be used. A compound having an ethylenically unsaturated bond is curable by radical polymerization (or crosslinking) reaction, and is generally called a monomer or an oligomer.
Specifically, (meth) acrylic acid, (meth) acrylic acid ester (for example, methyl (meth) acrylate, butyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy Propyl (meth) acrylate), ethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, styrene, divinylbenzene, (meth) acrylamide, vinyl acetate, N-hydroxymethyl (meth) acrylamide, dipentaerystol Examples include hexaacrylate, melamine acrylate, epoxy acrylate prepolymer, and diallyl phthalate.

In view of exposure sensitivity and various resistances after curing, the photopolymerizable compound is preferably a compound having two or more ethylenically unsaturated bonds.
In the present specification, “(meth) acryl” means methacryl and / or acryl, and “(meth) acrylate” means methacrylate and / or acrylate.

  The type of the photopolymerization initiator is not particularly limited. For example, α-hydroxyacetophenones, α-aminoacetophenones, biimidazoles, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl methyl ketal, Examples include α-halogenoacetophenones, methylphenylglyoxylate, benzyl, anthraquinone, phenanthrenequinone, camphorquinone isophthalophenone, acylphosphine oxide, and the like. These photoinitiators may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the polythiol compound in the photopolymerizable composition can be 10 parts by mass or more and 800 parts by mass or less with respect to 100 parts by mass of the photopolymerizable compound, and the content of the photopolymerization initiator is photopolymerizable. The amount can be 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the compound. If the content of the polythiol compound is 10 parts by mass or more, the blending effect of the polythiol compound can be obtained. If the content of the polythiol compound is 800 parts by mass or less, the cured product of the photopolymerizable composition is unlikely to be fragile. In addition, if the content of the photopolymerization initiator is 0.1 parts by mass or more, the reactivity of the curing reaction is sufficient, and if it is 5 parts by mass or less, there are few components not involved in crosslinking, so the photopolymerizable composition. Hardened product is difficult to become fragile.

  Normally, photocuring by radical polymerization is difficult to complete at the interface with air due to inhibition of polymerization by oxygen in the air. Therefore, generally, an oxygen blocking layer such as a cover film is provided so that oxygen does not touch the surface, or photocuring is performed in an inert gas atmosphere such as argon gas or nitrogen. However, since the photopolymerizable composition of the present embodiment has sufficient curability regardless of the presence or absence of oxygen, it is an application in which an oxygen blocking film cannot be provided or an application in which an oxygen blocking film is not provided. Can also be preferably used.

Examples of active energy rays used for photopolymerization include ultraviolet rays, electron beams, and X-rays, but ultraviolet rays are preferable because an apparatus serving as a light source is inexpensive.
The light source for curing the photopolymerizable composition with ultraviolet rays is not particularly limited, but specific examples include black light, UV-LED lamp, high pressure mercury lamp, pressurized mercury lamp, metal halide lamp, xenon lamp. And electrodeless discharge lamps. Of these light sources, black light and LED lamps (UV-LED lamps) are preferable because they are safe and economical.

  Here, the black light means that a near-ultraviolet phosphor is applied to a special outer tube glass cut from radiation of visible light and ultraviolet light having a wavelength of 300 nm or less, and a wavelength of 300 nm to 430 nm (wavelength peak is around 350 nm). It is a lamp that only emits near ultraviolet rays. The UV-LED lamp is a lamp using a light emitting diode that emits ultraviolet rays.

The irradiation amount of the active energy ray may be an amount sufficient for curing the photopolymerizable composition, and may be selected according to the composition, amount, thickness, shape of the cured product to be formed, and the like. Good. For example, a thin film (e.g., coating film formed by a coating method) of the photopolymerizable composition if ultraviolet is irradiated to cure against, be 200 mJ / cm ² or more 5000 mJ / cm ² or less of exposure can, more preferably 1000 mJ / cm ² or more 3000 mJ / cm ² or less of the exposure amount.

<(2-3) Other curable compositions>
Since the polythiol compound of the present embodiment reacts with the photopolymerizable compound by the photopolymerization initiator and is photocured, a cured product can be obtained. However, the basic compound can react with the ethylenically unsaturated group (so-called thiolene). Reaction), a cured product can be obtained even with a basic compound. Therefore, the composition containing the polythiol compound of the present embodiment, the compound having an ethylenically unsaturated bond, and the basic compound is also a curable composition for obtaining a cured product (hereinafter referred to as “thiolene curable composition”). May be written as ")". The thiolene curable composition may further contain various additives as desired.

Specific examples of the compound having an ethylenically unsaturated bond include various (meth) acrylates exemplified in Section 2-2.
Specific examples of the basic compound include various amine-based curing accelerators, guanidine-based curing accelerators, and imidazole-based curing accelerators exemplified in Section 2-1.

  Regarding the blending amount of the polythiol compound and the compound having an ethylenically unsaturated bond in the thiolene curable composition, the ratio of the number of mercapto groups of the polythiol compound to the number of ethylenically unsaturated groups of the compound having an ethylenically unsaturated bond Is preferably blended so that the ratio is 0.6 or more and 1.4 or less. When the ratio of the numbers is 0.6 or more, the thiolene curable composition can be cured, and the characteristics based on the carbonate skeleton can be imparted to the thiolene curable composition and the cured product thereof.

<(2-4) Various additives>
As described above, each curable composition of the present embodiment, that is, the epoxy composition, the photopolymerizable composition, and the thiolene curable composition has viscosity, operability, cured product characteristics, and the like according to the application. Various additives may be added to impart.
For example, sufficient dispersion of each raw material of each curable composition, operability at the time of application of each curable composition, improvement of adhesion of the cured product of each curable composition, viscosity adjustment of each curable composition For the purpose, a volatile solvent may be added.

Examples of the volatile solvent include alcohols, ketones, esters and the like. Specific examples of volatile solvents include methanol, ethanol, toluene, cyclohexane, isophorone, cellosolve acetate, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, xylene, ethylbenzene, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, isoamyl acetate , Ethyl lactate, methyl ethyl ketone, acetone, cyclohexanone and the like. These solvents may be used alone or in combination of two or more.
However, from the viewpoint of environmental load, the curable composition is preferably solvent-free and can be made solvent-free by using the polythiol compound of this embodiment.

  Furthermore, each curable composition of the present embodiment includes a polymerization inhibitor, a fluorescent whitening agent, a surfactant, a plasticizer, a flame retardant, an antioxidant, an ultraviolet absorber, a foaming agent, an antibacterial agent, depending on the purpose. A fungicide, an antistatic agent, a magnetic material, a conductive material, an antibacterial / bactericidal material, a porous adsorbent, a fragrance, a pigment, a dye, and the like may be added.

<(2-5) Preparation method of curable composition>
The preparation method of each curable composition (epoxy composition, photopolymerizable composition, and thiolene curable composition) of the present embodiment is not particularly limited, and curing including the polythiol compound of the present embodiment. The material is not particularly limited as long as it can mix and disperse each raw material of the composition. Examples of the method of mixing and dispersing include the following methods.

(A) Each raw material is charged into a glass beaker, can, plastic cup, aluminum cup or the like and kneaded with a stir bar or spatula.
(B) Each raw material is kneaded with a double helical ribbon blade, a gate blade, or the like.
(C) Each raw material is kneaded with a planetary mixer.
(D) Each raw material is kneaded by a bead mill.
(E) Each raw material is kneaded with three rolls.
(F) Each raw material is kneaded by an extruder-type kneading extruder.
(G) Each raw material is kneaded by a rotating / revolving mixer.

<(2-6) About processing method of curable composition>
The application (coating) method in the case where each curable composition (epoxy composition, photopolymerizable composition, and thiolene curable composition) of this embodiment is applied onto a substrate to form a coating film, for example, There is no particular limitation. For example, in addition to spray method and dip method, natural coater, curtain flow coater, comma coater, gravure coater, micro gravure coater, die coater, curtain coater, kiss roll, squeeze roll, reverse roll, air blade, knife belt coater, floating knife , A method using a knife over roll, a knife on blanket or the like.
By processing each curable composition of the present embodiment into a sheet and curing it, a sheet material made of a cured product is obtained. This sheet | seat material may contain other components other than each curable composition of this embodiment as needed.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
(1) Synthesis of polythiol compound [Synthesis Example 1]: Synthesis of polythiol compound (S-1) Polycarbonate polyol (A) having a weight average molecular weight of 500, polycarbonate diol (trade name, Kuraray Polyol C-590, manufactured by Kuraray Co., Ltd.) The diol component is 3-methyl-1,5-pentanediol and 1,6-hexanediol (100 g, 200 mmol), and 3-mercaptobutanoic acid (Made by Showa Denko KK) which is a mercapto group-containing carboxylic acid (B). ) 58 g (480 mmol), 7.6 g (40 mmol) of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst, and 150 g of toluene (manufactured by Junsei Chemical Co., Ltd.) as a solvent, Charged to a 500 mL flask equipped with a Dean-Stark device and a condenser. . And after reducing the pressure in the reaction system to 73.3 kPa (550 mmHg), stirring of the contents of the flask was started while heating using an oil bath at 120 ° C.

While removing the water produced by the reaction from the reaction system with a Dean-Stark apparatus, the mixture was heated and stirred for 4 hours and then allowed to cool to room temperature. It was summed up. Furthermore, after the organic layer was washed three times with ion exchange water, the solvent (toluene) was distilled off from the organic layer by reducing the pressure using a vacuum pump to obtain a pale yellow transparent liquid.
The obtained pale yellow transparent liquid was a polythiol compound having a thiol equivalent of 352 and a weight average molecular weight of 760, and the yield was 124 g and the yield was 88%.

[Synthesis Example 2]: Synthesis of Polythiol Compound (S-2) Polycarbonate polyol (A) polycarbonate diol having a weight average molecular weight of 1000 (trade name Kuraray Polyol C-1090 manufactured by Kuraray Co., Ltd., diol component is 3-methyl- 500 g (500 mmol) of 1,5-pentanediol and 1,6-hexanediol), 144 g (1198 mmol) of 3-mercaptobutanoic acid (manufactured by Showa Denko KK) which is a mercapto group-containing carboxylic acid (B), 19 g (99.8 mmol) of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst and 500 g of toluene (manufactured by Junsei Chemical Co., Ltd.) as a solvent are mixed with a Dean-Stark apparatus and a cooling pipe. Was charged into a 2 L flask. And after reducing the pressure in the reaction system to 73.3 kPa (550 mmHg), stirring of the contents of the flask was started while heating using an oil bath at 120 ° C.

The water produced by the reaction was removed from the reaction system with a Dean-Stark apparatus, and the mixture was heated and stirred for 7 hours and then allowed to cool to room temperature. The resulting reaction solution was diluted with an aqueous sodium hydrogen carbonate solution having a concentration of 5% by mass. It was summed up. Furthermore, after the organic layer was washed three times with ion exchange water, the solvent (toluene) was distilled off from the organic layer by reducing the pressure using a vacuum pump to obtain a pale yellow transparent liquid.
The obtained pale yellow transparent liquid was a polythiol compound having a thiol equivalent of 591 and a weight average molecular weight of 1200, and the yield was 557 g and the yield was 94%.

[Synthesis Example 3]: Synthesis of Polythiol Compound (S-3) Polycarbonate polyol (A) polycarbonate diol having a weight average molecular weight of 1000 (trade name Kuraray Polyol C-1015 manufactured by Kuraray Co., Ltd., diol component is 2-methyl- 110 g (110 mmol) which is 1,8-octanediol and 1,9-nonanediol) and 31.7 g (264 mmol) of 3-mercaptobutanoic acid (manufactured by Showa Denko KK) which is a mercapto group-containing carboxylic acid (B) And 4.2 g (22 mmol) of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst and 130 g of toluene (manufactured by Junsei Chemical Co., Ltd.) as a solvent, and Dean-Stark apparatus and A 500-mL flask equipped with a condenser was charged. And after reducing the pressure in the reaction system to 73.3 kPa (550 mmHg), stirring of the contents of the flask was started while heating using an oil bath at 120 ° C.

While removing the water produced by the reaction from the reaction system with a Dean-Stark apparatus, the mixture was heated and stirred for 4 hours and then allowed to cool to room temperature. The resulting reaction solution was neutralized with an aqueous sodium hydrogen carbonate solution having a concentration of 9% by mass. It was summed up. Furthermore, after the organic layer was washed three times with ion exchange water, the solvent (toluene) was distilled off from the organic layer by reducing the pressure using a vacuum pump to obtain a pale yellow transparent liquid.
The obtained pale yellow transparent liquid was a polythiol compound having a thiol equivalent of 611 and a weight average molecular weight of 1320, and the yield was 118 g and the yield was 89%.

[Synthesis Example 4]: Synthesis of polythiol compound (S-4) Polycarbonate polyol (A) having a weight average molecular weight of 2000, polycarbonate diol (trade name Kuraray Polyol C-2090, manufactured by Kuraray Co., Ltd., diol component is 3-methyl- 250 g (125 mmol) of 1,5-pentanediol and 1,6-hexanediol), 36 g (300 mmol) of 3-mercaptobutanoic acid (manufactured by Showa Denko KK) which is a mercapto group-containing carboxylic acid (B), 4.8 g (25 mmol) of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst and 300 g of toluene (manufactured by Junsei Kagaku Co., Ltd.) as a solvent are combined with a Dean-Stark apparatus and a cooling pipe. Was placed in a 1 L flask equipped with And after reducing the pressure in the reaction system to 73.3 kPa (550 mmHg), stirring of the contents of the flask was started while heating using an oil bath at 120 ° C.

The water produced by the reaction was removed from the reaction system with a Dean-Stark apparatus, and the mixture was heated and stirred for 7 hours and then allowed to cool to room temperature. The resulting reaction solution was diluted with an aqueous sodium hydrogen carbonate solution having a concentration of 5% by mass. It was summed up. Furthermore, after the organic layer was washed three times with ion exchange water, the solvent (toluene) was distilled off from the organic layer by reducing the pressure using a vacuum pump to obtain a pale yellow transparent liquid.
The obtained pale yellow transparent liquid was a polythiol compound having a thiol equivalent of 1102 and a weight average molecular weight of 2300, and the yield was 218 g and the yield was 79%.

[Synthesis Example 5]: Synthesis of polythiol compound (S-5) Polycarbonate polyol (A) polycarbonate diol having a weight average molecular weight of 3000 (trade name Kuraray Polyol C-3090 manufactured by Kuraray Co., Ltd., diol component is 3-methyl- 250 g (83 mmol) of 1,5-pentanediol and 1,6-hexanediol), 24 g (200 mmol) of 3-mercaptobutanoic acid (made by Showa Denko KK) which is a mercapto group-containing carboxylic acid (B), 3.2 g (16.7 mmol) of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst and 277 g of toluene (manufactured by Junsei Kagaku Co., Ltd.) as a solvent are combined with a Dean-Stark apparatus and A 1 L flask equipped with a condenser was charged. And after reducing the pressure in the reaction system to 73.3 kPa (550 mmHg), stirring of the contents of the flask was started while heating using an oil bath at 120 ° C.

The water produced by the reaction is heated and stirred for 11 hours while removing water from the reaction system with a Dean-Stark apparatus, and then allowed to cool to room temperature. It was summed up. Furthermore, after the organic layer was washed three times with ion exchange water, the solvent (toluene) was distilled off from the organic layer by reducing the pressure using a vacuum pump to obtain a pale yellow transparent liquid.
The obtained pale yellow transparent liquid was a polythiol compound having a thiol equivalent of 1602 and a weight average molecular weight of 3330, and the yield was 201 g and the yield was 75%.

[Synthesis Example 6]: Synthesis of polythiol compound (S-6) The same operation as in Synthesis Example 1 was performed except that 51 g of 3-mercaptopropionic acid (manufactured by Aldrich) was used instead of 58 g of 3-mercaptobutanoic acid. To obtain the desired compound. The obtained compound was a polythiol compound having a thiol equivalent of 331 and a weight average molecular weight of 680, and the yield was 130 g and the yield was 96%.

In addition, the measuring method of the weight average molecular weight and thiol equivalent of polythiol compound (S-1)-(S-6) obtained by the synthesis | combination is as follows.
[Method for measuring weight average molecular weight]
The weight average molecular weights of the polythiol compounds (S-1) to (S-6) in Synthesis Examples 1 to 6 were measured by gel permeation chromatography. The measurement conditions are shown below.
Column: Shodex LF-804 × 3 manufactured by Showa Denko KK Eluent composition: Tetrahydrofuran Eluent flow rate: 1 mL / min Temperature: 40 ° C.
Detector: RI-2031Plus manufactured by JASCO Corporation

[Method for measuring thiol equivalent]
The thiol equivalent represents the molecular weight per unit quantity of mercapto groups and can be measured as follows.
1.0 g of a measurement sample is precisely weighed, and 20 mL of chloroform is added thereto to obtain a sample solution. A solution obtained by dissolving 0.275 g of soluble starch in 30 g of pure water is prepared as a starch indicator, and 20 mL of pure water, 10 mL of isopropyl alcohol, and 1 mL of starch indicator are added to the sample solution and stirred with a stirrer. Thereto, an iodine solution (manufactured by Wako Pure Chemical Industries, Ltd., concentration 0.05 mol / L, factor 1.003 (20 ° C.)) is dropped, and the point at which the chloroform layer exhibits green is defined as the end point. At this time, the value given by the following formula is the thiol equivalent of the measurement sample.

Thiol equivalent = mass of measurement sample (g) × 10000 / (titration amount of iodine solution (mL) × factor of iodine solution)
The mercapto group is oxidized by iodine to disulfide. A typical reaction is shown in the following formula.
2R-SH + I ₂ → RSS-S + 2HI

  R in the above formula is an arbitrary organic group. When all the mercapto groups are consumed, an iodine starch reaction occurs between iodine and starch and color develops, which can be used as an end point. The factor here is a correction coefficient, and is a value determined for each titration reagent in order to offset the volume uncertainty that changes depending on the concentration and density when performing quantitative analysis by volume.

Further, the structures of the polythiol compounds (S-1) to (S-6) of Synthesis Examples 1 to 6 were analyzed by proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR) and Fourier transform infrared spectroscopy (FT-IR). did. The analysis conditions are shown below.
[Nuclear magnetic resonance spectroscopy]
The polythiol compounds (S-1) to (S-6) of Synthesis Examples 1 to 6 were each dissolved in deuterated chloroform, and using a nuclear magnetic resonance apparatus JNM-AL400 manufactured by JEOL Ltd., nuclear magnetic resonance spectroscopy analysis. Went. ¹ H-NMR charts are shown in FIGS. Then, attribution was performed for the major chemical shift peaks.

  The following chemical formula (IV) shows a portion corresponding to the mercapto group-containing carboxylic acid (B) located at the terminal of the polythiol compound (R in the chemical formula (IV) is a portion corresponding to the polycarbonate polyol (A)) The peak at 4.1 to 4.5 ppm in the charts of FIGS. 1 to 6 is attributed to the hydrogen of the methylene group marked with a in the chemical formula (IV). Moreover, the peak of 1.8-1.9 ppm of the chart of FIGS. 1-6 is attributed to the hydrogen of the mercapto group which attached | subjected the e mark in Chemical formula (IV). Furthermore, the 1.4 ppm peak in the charts of FIGS. 1 to 6 is attributed to hydrogen of a methyl group marked with d in the chemical formula (IV).

[Fourier transform infrared spectroscopy]
Using the FT-IR spectroscope Nicolet iS10 manufactured by Thermo Scientific, the polythiol compounds (S-1) to (S-6) of Synthesis Examples 1 to 6 were subjected to Fourier transform infrared spectroscopic analysis. It was carried out to confirm the peak of specific 2550cm ^-1 to peak and the mercapto group of 3400cm ^-1. FT-IR charts are shown in FIGS.

(2) Preparation of curable composition and production of cured product thereof [Example A1]: Preparation of epoxy composition (E-1) and production of cured product thereof Polythiol compound obtained in Synthesis Example 1 (S-1) ) 40 parts by mass, 60 parts by mass of trimethylolpropane polyglycidyl ether (Denacol EX321 manufactured by Nagase ChemteX Corporation) as an epoxy compound having two or more epoxy groups, and an amine curing accelerator (manufactured by Mitsubishi Chemical Corporation) An epoxy composition (E-1) was obtained by mixing 4 parts by mass of a tertiary amine curing accelerator jER3010).

  In this mixing, the polythiol compound (S-1), trimethylolpropane polyglycidyl ether, and amine-based curing accelerator are put into a sealed plastic container having a capacity of 150 mL. Was used by stirring for 1 minute at a stirring mode and a rotational speed of 2000 rpm.

When mixing was completed, the lid of the sealed plastic container was opened, and the odor felt when the lid was opened was evaluated. And the smell of the epoxy composition (E-1) was evaluated based on the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
A: Small odor
B: Odor but not uncomfortable
C: There is an unpleasant odor

Next, the pot life of the epoxy composition (E-1) obtained as described above was evaluated. The results are shown in Table 1. The pot life was evaluated by the speed of thickening when the epoxy composition (E-1) was allowed to stand at room temperature. The evaluation criteria are as follows.
(Evaluation criteria)
A: No thickening even after standing for 30 minutes or more
B: There is thickening within 30 minutes of standing
C: Curing occurs within 30 minutes during stirring or standing at the time of preparation of the curable composition

  Next, the obtained epoxy composition (E-1) obtained as described above is filled in a mold and cured by heating at 160 ° C. for 20 minutes to cure the epoxy composition (E-1). I got a thing. This mold consists of a 50 mm long, 50 mm wide, 3 mm thick glass plate, a 50 mm long, 50 mm wide, 5 mm thick silicon rubber outer mold, and a 30 mm long, 30 mm wide, 5 mm thick silicon rubber. The inner mold made of the product is placed and adhered. The epoxy composition (E-1) was poured into a gap between the outer mold and the inner mold on the glass plate, and was cured by heating.

During the curing, the curability of the epoxy composition (E-1) was evaluated based on the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
A: Completely cured, and a cured product having a shape along the shape of the mold was obtained.
B: Although the liquid component does not remain, the shape collapsed when force was applied to the cured product
C: not cured

Next, the flexibility and impact resistance of the cured product of the epoxy composition (E-1) obtained as described above were evaluated. The results are shown in Table 1.
The flexibility was evaluated by the hardness (Shore D) of the cured product measured using a Shore hardness tester D type manufactured by Imai Seiki Co., Ltd. The lower the numerical value obtained by measurement, the higher the flexibility.
The impact resistance was evaluated based on the height (bounce height) of a 40 g hard ball rebounded when dropped onto a cured product from a height of 60 cm. The lower the bounce height value, the higher the impact resistance. The better the shock absorbing properties, the lower the bounce height value. It should be noted that the evaluation was not possible when the sample was destroyed.

[Examples A2 to A9, Comparative Examples A1 to A3]: Preparation of Epoxy Compositions (E-2) to (E-12) and Production of Cured Products As shown in Table 1, the types and amounts used of each raw material Except for the point changed to, the same operations as in Example A1 were performed to obtain epoxy compositions (E-2) to (E-12) and cured products thereof. And it carried out similarly to Example A1, and evaluated epoxy composition (E-2)-(E-12) and those hardened | cured material. The results are shown in Table 1.
In addition, Karenz MT (registered trademark) PE1 described in Table 1 is pentaerythritol tetrakis (3-mercaptobutyrate) manufactured by Showa Denko KK.

[Example B1]: Preparation of photopolymerizable composition (P-1) and production of cured product thereof 40 parts by mass of polythiol compound (S-1) obtained in Synthesis Example 1 and trimethylol as a photopolymerizable compound 48 parts by mass of propane triacrylate (Aronix M-309 manufactured by Toagosei Co., Ltd.), 12 parts by mass of dipentaerythritol hexaacrylate (Aronix M-405 manufactured by Toagosei Co., Ltd.) as a photopolymerizable compound, and photopolymerization started A photopolymerizable composition (P-1) was obtained by mixing 3 parts by mass of ethyl phenyl (2,4,6-trimethylbenzoyl) phosphinate (Lucirin TPO-L manufactured by BASF) as an agent.

In this mixing, as in Example A1, each raw material such as polythiol compound (S-1) is placed in a 150 mL sealed plastic container, and a rotating and rotating stirrer manufactured by Shinkey Co., Ltd. The stirring mode was performed by stirring for 1 minute at a rotation speed of 2000 rpm.
When mixing was completed, the odor and pot life of the photopolymerizable composition (P-1) were evaluated in the same manner as in Example A1. The results are shown in Table 2.

Next, the photopolymerizable composition (P-1) obtained as described above is filled in the same mold as in Example A1, and light is applied so that the integrated exposure amount becomes ² J / cm ^2. Irradiated and cured to obtain a cured product of the photopolymerizable composition (P-1). Light irradiation was performed using a conveyor-type high-pressure mercury irradiation apparatus ECS-4001GX manufactured by Eye Graphics Co., Ltd.
During the curing, the curability of the photopolymerizable composition (P-1) was evaluated in the same manner as in Example A1. The results are shown in Table 2.
Further, the flexibility and impact resistance of the cured product of the photopolymerizable composition (P-1) obtained as described above were evaluated in the same manner as in Example A1. The results are shown in Table 2.

[Examples B2 to B9, Comparative Examples B1 to B3]: Preparation of Photopolymerizable Compositions (P-2) to (P-12) and Manufacture of Their Cured Products Except for the points changed as shown, the same operations as in Example B1 were performed to obtain photopolymerizable compositions (P-2) to (P-12) and cured products thereof. And like Example B1, photopolymerizable composition (P-2)-(P-12) and those hardened | cured materials were evaluated. The results are shown in Table 2.

  As can be seen from the results shown in Tables 1 and 2, Examples A1 to A9, Examples B1 to B9, and Comparative Examples A3 and B3, which are curable compositions using a polythiol compound having a carbonate skeleton, are polythiol compounds. Flexibility is higher than Comparative Examples A1 and B1, which are curable compositions that are not used. Therefore, since the hardness is low and impact resistance is imparted, the rebound height of the dropped steel ball was 3/4 or less.

However, even if it had a carbonate skeleton, Comparative Examples A3 and B3 using a polythiol compound which is a primary thiol had unpleasant odors and could not be put into practical use.
As for the pot life, in the case of the photopolymerizable composition, a sufficient pot life could be secured regardless of whether the polythiol compound was primary or secondary. On the other hand, in the case of the epoxy composition, even if the polythiol compound was a secondary thiol, Comparative Example A2 having a thiol equivalent of less than 200 could not ensure sufficient pot life because curing was too fast. Therefore, a flexible and impact resistant sample could not be produced.

Claims (7)

It is an esterified product of the hydroxy group of the polycarbonate polyol (A), which is a polycarbonate having a plurality of hydroxy groups, and the carboxy group of a mercapto group-containing carboxylic acid (B) represented by the following chemical formula (I). A polythiol compound having a plurality of mercapto groups.
However, R ¹ in the following chemical formula (I) represents a branched alkylene group having 2 to 10 carbon atoms.

The polythiol compound according to claim 1, wherein the mercapto group-containing carboxylic acid (B) is at least one of a compound represented by the following chemical formula (II) and a compound represented by the following chemical formula (III).

  The polythiol compound according to claim 1 or 2, wherein the polycarbonate polyol (A) has a weight average molecular weight of 400 or more and 5000 or less.   The polycarbonate polyol (A) is at least one selected from 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,6-hexanediol, and 1,9-nonanediol. The polythiol compound according to any one of claims 1 to 3, which has a structure derived from a diol component.   A curable composition containing the polythiol compound according to any one of claims 1 to 4 and an epoxy compound having two or more epoxy groups.   The curable composition containing the polythiol compound as described in any one of Claims 1-4, a photopolymerizable compound, and a photoinitiator.   Hardened | cured material of the curable composition of Claim 5 or Claim 6.

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