JPH07700B2 - Photocurable composition and laminate using the same as an adhesive layer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a curable composition comprising a polyene, a mercapto group-containing polymer and a photopolymerization initiator, and is particularly required to have water resistance and moisture resistance. It is useful as an adhesive, paint and sealant.

(Prior Art) It is well known that polyene and polythiol form a polymer upon irradiation with actinic rays (J. Am. Chem. So.
c., 70, 993 (1948), by changing the chemical equivalent of the carbon-carbon unsaturated double bond of polyene and the mercapto group of polythiol, or by changing the number of functional groups of polyene and polythiol Various cured products can be obtained.

(Problems to be Solved by the Invention) Most of the polythiols used are the polyhydric alcohol esters of thioglycolic acid and thiopropionic acid disclosed in JP-B-47-3269. However, because of the low molecular weight of these substances,
The composition combined with polyene has a very low viscosity and cannot be used as an adhesive, paint, sealant or the like in a portion where a thickness is required. In addition, since they have an ester bond in the molecule, the cured product of the composition using these polythiols has a drawback that it is easily hydrolyzed under high humidity to be softened or eluted. Naturally, this phenomenon is also observed when there is an ester bond in the polyene molecule. As a method for improving the viscosity, as disclosed in JP-B-57-1535, a method in which a mercapto group-containing polymer obtained by reacting a polythiol with a polyepoxide in excess of polythiol is used as one component of the composition However, even in this report, since the above-mentioned ester group-containing polythiol is used, the problem of hydrolysis has not been solved.

An object of the present invention is to provide a photocurable composition having a mercapto group-containing polymer whose viscosity can be easily adjusted over a wide range, comprising a polyene and a photopolymerization initiator, and having excellent water resistance and moisture resistance.

(Means for Solving Problems) That is, the present invention is: 1. A polyepoxide having no ester bond and a polythiol having no ester bond in which the molar ratio of all mercapto groups to all epoxy groups thereof is 1.1 to 100. A photocurable composition comprising a mercapto group-containing polymer, which is a reaction product with, a polyene having no ester bond, and a photopolymerization initiator, and 2. a polyepoxide having no ester bond and all epoxy groups thereof. On the other hand, a photocurable composition comprising a mercapto group-containing polymer which is a reaction product with a polythiol having no ester bond having a molar ratio of all mercapto groups of 1.1 to 100, a polyene having no ester bond and a photopolymerization initiator. A laminate comprising an object as an adhesive layer, both or one of which is made of a material capable of transmitting an actinic ray.

The mercapto group-containing polymer obtained from the polyepoxide and polythiol described in 1. above has a repeating unit represented by the following general formula [I], the unterminated end is a --SH group, and the molecular weight is from 350 to 500,000. .

(In the formula, t, w and x are integers of 1 to 5, n is a number of 0 or 1, A is oxygen or sulfur, and R has no ester bond.
A valent or trivalent residue is shown. ) The above-mentioned mercapto group-containing polymer can be obtained by reacting the epoxy group of the polyepoxide having no ester bond represented by the general formula [II] with the mercapto group of the polythiol represented by the general formula [III]. it can.

(Wherein, R is as defined for formula (I), m is an integer of 2 or _{3.) HSC t H 2t -A} w C x H 2x -SH ... (III) (where, t, w, x , A is the same as the above formula [I].) This reaction may proceed in a sequential reaction.

Representative examples of the mercapto group-containing polymer thus obtained include those represented by the following formulas.

(However, u is an integer from 1 to 950) Examples of the polyepoxide represented by the above general formula [II] include bisphenol A type epoxide, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether,
1,6-hexanediol diglycidyl ether, dibromonepentyl glycol diglycidyl ether, glycerol diglycidyl ether, glycerol tridiglycidyl ether, trimethylolpropane diglycidyl ether, trimethylolpropane tridiglycidyl ether, diglycerol polyglycidyl ether, bisphenol S Type epoxide, dicyclopentadiene, phenolic polymer epoxy resin, bisphenol F type epoxide, brominated bisphenol F type epoxide, hydrogenated bisphenol A type epoxide, tris (2,3-epoxypropane) isocyanurate, and the like.
It is not limited to these. Moreover, you may use the mixture of 2 or more types of these.

Further, as the polythiol represented by the above general formula [III], diglycol dimercaptan, triglycol dimercaptan, tetraglycol dimercaptan,
Examples thereof include thiodiglycol dimercaptan, thiotriglycol dimercaptan, and thiotetraglycol dimercaptan, but are not limited to these polyvalent thiols. Moreover, you may use the mixture of 2 or more types of these. Particularly preferred is one having a viscosity of 1 to 10,000 cps at 25 ° C.

The synthesis of the mercapto group-containing polymer with the above polyepoxide and polythiol is carried out by mixing the two at a temperature of 0 ° C. or higher and stirring. If necessary, a catalyst may be used, and examples thereof include tertiary amines such as those listed in “Thermosetting Resin” Volume 2, Page 140 (1981), and the like. Third phosphine, etc. The molar ratio of mercapto group to epoxy group is preferably 1.1 to 100 of mercapto group / epoxy group, particularly preferably 1.4 to 2
It is 0. When the molar ratio is less than 1.1, gelation and disappearance of the mercapto group occur. If the molar ratio exceeds 100, no modification with epoxide is observed. Further, the viscosity of the mercapto group-containing polymer can be adjusted extremely widely and freely by changing the molar ratio. In this reaction, since the mercapto group is in excess, the product is i) unreacted polythiol ii) one polyepoxide molecule reacted with polythiol iii) polyepoxide- In most cases, it can be obtained in the form of a mixture of those having a polythiol reactant as a repeating unit. Therefore, in order to obtain a single compound from these, separation and purification may be necessary.

As the polyene having no ester bond for ammonia in the mercapto group-containing polymer obtained as described above, divinylbenzene, divinyltoluene, triallyl cyanurate, triallyl isocyanurate, tetraallyloxyethane, trimethylolpropane diallyl. Ether, trimethylolpropane triallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, pentaerythritol tetraallyl ether, ethylene glycol di (meth) allyl ether, propylene glycol di (meth) allyl ether, butylene glycol di (meth) Allyl ether, polyethylene glycol di (meth) allyl ether, polypropylene glycol di (meth) allyl ether, polybutylene glycol Di (meth) allyl ether, di (meth) allyl ether of glycol which is a block or random copolymer of ethylene oxide and propylene oxide, di (meth) allyl ether of glycol which is a block or random copolymer of ethylene oxide and tetrahydrofuran. Examples include, but are not limited to, di (meth) allyl ether of bisphenol A, di (meth) allyl ether of (poly) ethylene oxide modified bisphenol A, and di (meth) allyl ether of (poly) propylene oxide modified bisphenol A. It is not something that will be done.

Moreover, you may use the mixture of 2 or more types of these.

The ratio of the mercapto group-containing polymer and the polyene used in the composition of the present invention is determined by the molar ratio of the mercapto group of the mercapto group-containing polymer and the carbon-carbon unsaturated double bond of the polyene, and the ratio is 1.5: 1 to. 1: 1.5, preferably 1.2: 1
~ 1: 1.2, most preferably about 1: 1. When the ratio of the mercapto group-containing polymer and the polyene is out of the above range, problems such as an offensive odor after curing and a cured product having too low hardness may occur and curing may not occur in a remarkable case.

Examples of the photopolymerization initiator used in the present invention include benzophenone, p-methoxybenzophenone, 4,4-bisdimethylaminobenzophenone, xanthone, thioxanthone, chlorothioxanthone, m-chloroacetone, propiophenone, anthraquinone, and benzoinmethyl. Ether, benzoin ethyl ether, benzoin propyl ether, benzoin butyl ether, benzyl, benzyl dimethyl ketal, acetone phenone, 2,2-diethoxy acetophenone, 2-hydroxy 2,2-dimethyl acetophenone and the like, but are not limited to these. Not a thing. The amount of the photopolymerization initiator used is 0.01 with respect to the total 100 parts by weight of the mercapto group-containing polymer and polyene.
-5 parts by weight is preferred.

The composition of the present invention contains the mercapto group-containing polymer, polyene, a photopolymerization initiator as an essential component, and if necessary, an antioxidant, a polymerization inhibitor, a plasticizer, a thixotropy imparting agent, a silane coupling agent. Additives such as agents, chelating agents, curing accelerators, dyes, pigments, fillers, antistatic agents, and surfactants may be used within the range that does not impair the object of the present invention.

A laminate having the photocurable composition thus prepared as an adhesive layer is provided by coating the photocurable composition on one side of two plates or films, both or one of which can transmit actinic rays. , After laying the two sheets, irradiating the active ray from the transparent side, sandwiching a spacer of arbitrary thickness between two plates or films, both or one of which can transmit the active ray,
The photocurable composition of the present invention is cast and then irradiated with actinic rays from the transparent side (cured / bonded) to prepare. Examples of the material that can transmit actinic rays include glass, polycarbonate, polystyrene, and acrylic resin, but are not limited thereto. Further, if actinic rays are transmitted, it is possible to prepare a laminate in which three or more plates or films are stacked and a photocurable composition is interposed therebetween.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples.

Example 1 Triglycol dimercaptan 94 was added to a 3 liter glass reactor.
7 g, bisphenol A type epoxide 553 g, and 2,4,6-tris (dimethylaminomethyl) phenol 1.2 g were added, and the mixture was heated to a temperature of 150 ° C. and reacted for 8 hours while stirring. The concentration of mercapto group in this product was 4.3 mmol / g.

This product and triallyl isocyanurate were mixed so that the molar ratio of mercapto group: vinyl group was 1: 1, and 0.2 parts by weight of benzyl dimethyl ketal was added (compounding viscosity 700 cps) to obtain polyethylene of 25φ × 5 mm. It filled in the cup made and irradiated for 30 minutes at the distance of 30 cm under a 400-w ultraviolet lamp.

When the obtained cured product was allowed to stand for 40 days at a temperature of 70 ° C. and a humidity of 80% and compared with the hardness immediately after curing, no decrease in hardness was observed. Table 1 collectively shows these conditions and results.

Example 2 760 g of triglycol dimercaptan, bisphenol A
Example 1 was repeated except that 740 g of the type epoxide was used. The conditions and results are shown in Table 1.

Example 3 676 g of triglycol dimercaptan, bisphenol A
Example 1 was repeated except that 824 g of type epoxide was used. The conditions and results are shown in Table 1.

Example 4 Triglycol dimercaptan 11 was added to a 3 liter glass reactor.
29 g and 371 g of tris (2,3-epoxypropyl) isocyanurate were added, and the mixture was heated to a temperature of 120 ° C. and reacted for 8 hours while stirring. Using the mercapto group-containing polymer thus obtained, a cured product was prepared in the same manner as in Example 1 and subjected to a moisture resistance test. The conditions and results are shown in Table 1.

Example 5 Except that 1002 g of triglycol dimercaptan and 498 g of tris (2,3-epoxypropyl) isocyanurate were used,
The same procedure as in Example 4 was performed. The conditions and results are shown in Table 1.

Example 6 Triglycol dimercaptan in a 3 l glass reaction vessel
1050 g and triallyl isocyanurate 503.4 g were added, the temperature was raised to 60 ° C., and nitrogen bubbling (5 l / min) was performed in the liquid for 10 minutes while stirring. Then, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane (Perhexa 3M, manufactured by NOF CORPORATION) was added once every 30 minutes to 100 mg.
Each was added three times, and after the final addition, the reaction was carried out at 70 ° C. for 3 hours. The concentration of mercapto group in this product was 3.1 mmol / g.

Using this product, a cured product was prepared in the same manner as in Example 1 and subjected to a moisture resistance test. No decrease in hardness was observed (immediately after curing: Shore A-74, after moisture resistance test: Shore A-75. ).

Example 7 A silicon spacer (thickness: 0.5 mm) was sandwiched between two glass plates having a length of 200 mm, a width of 200 mm, and a thickness of 3 mm, and the glass end portion was covered with a polyester tape leaving a composition injection port. Sealed. The photocurable composition used in Example 1 was poured from the inlet to fill the gap, and then the inlet was sealed,
Irradiation was performed for 60 minutes at an ultraviolet intensity of ³ mw / cm ² to cure the composition, and a glass laminate was prepared. This laminated body is heated to a temperature of 70
When left for 100 days under conditions of ℃ and 80% humidity, no change was observed in the laminate.

Comparative Example 1 Triglycol dimercaptan 135 g, bisphenol A
Example 1 was repeated except that 1365 g of type epoxide was used. No mercapto group was found in this product. The conditions and results are shown in Table 2.

Comparative Example 2 A curing and moisture resistance test was conducted in the same manner as in Example 1 except that triglycol dimercaptan was used instead of the mercapto group-containing polymer. The result of the moisture resistance test was good, but the compounding viscosity was very low. The conditions and results are shown in Table 2.

Comparative Example 3 The procedure of Example 1 was repeated except that 1485 g of triglycol dimercaptan and 15 g of bisphenol A type epoxide were used. The concentration of mercapto group in this product was 11 mmol / g, which was the same as that of triglycol dimercaptan, and no modification with polyepoxide was observed. The conditions and results are shown in Table 2.

Comparative Example 4 Tris-2-hydroxyethyl isocyanurate Tris-β-mercaptopropionate 1186 g, bisphenol A type epoxide 314 g, and 2,4,6-tris (dimethylaminomethyl) phenol 1.2 g were used at a temperature of 80 ° C. The same procedure as in Example 1 was performed except that the reaction was performed for 10 hours. A very high viscosity was obtained, but the hardness was greatly reduced by the moisture resistance test. The conditions and results are shown in Table 2.

(Effects of the Invention) As described above, the photocurable composition of the present invention can have an extremely high viscosity and is useful as a sealant, an adhesive, or a paint in a portion where a thickness is required. . Further, since it is not hydrolyzed, it can be sufficiently used in a field requiring water resistance and moisture resistance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 81/02 LRG C09J 181/02 JJJ

Claims (2)

[Claims] 1. A polyepoxide having no ester bond and a molar ratio of all mercapto groups to all epoxy groups thereof are 1.
A photocurable composition comprising a mercapto group-containing polymer which is a reaction product of 1 to 100 with a polythiol having no ester bond, a polyene having no ester bond, and a photopolymerization initiator. 2. A molar ratio of all mercapto groups to polyepoxides having no ester bond and all epoxy groups thereof is 1.
A mercapto group-containing polymer which is a reaction product with a polythiol having no ester bond of 1 to 100, and a photocurable composition comprising a polyene having no ester bond and a photopolymerization initiator as an adhesive layer And a laminate comprising a material capable of transmitting an actinic ray.