JPS6375035A - Photo-curing composition - Google Patents

Abstract

PURPOSE:To provide the titled composition containing a specific polyene, a polythiol and a specific amount of photopolymerization initiator and capable of giving a cured product having excellent weather resistance even under high temperature and humidity condition. CONSTITUTION:The objective composition contains (A) a polyene free from the ester bond expressed by formula I [m is 2-6; R1-R3 are (substituted) alkyl, H, F, Cl, Br, (substituted) aryl or (substituted) alkoxy; Y is -(CH2)n- (n is 0-10), -(OCH2)p- (p is 1-10) or -O-(CH2)q- (q is 1-10); X and Y are atomic groups having m functional groups and may be bonded with each other] (e.g. divinylbenzene), (B) a polythiol of formula II or III (t, w and x are 1-5; A is O or S; R' is polyvalent organic residue; y is 1-2) (e.g. diglycol dimercaptan) and (C) 0.05-5pts.wt. of a photo-polymerization initiator (e.g. benzophenone) based on 100pts.wt. of A+B.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a photocurable composition containing and releasing a polyene and a polythiol.

(Prior art) It is well known that I-liene and prethiol form polymers by irradiation with actinic rays (C, S, Mar
rel et, al,, J, Am, Chem,
Soc, 70°993 (1948)], by changing the chemical equivalent of the carbon-carbon unsaturated double bond of poporin and the mercapto group of polythiol, and by changing the number of functional groups of polyene and polythiol, it is possible to change from elastomer-like to resin-like. Various cured products can be obtained. Furthermore, it is also possible to control the curing time by changing the amount of actinic light and the amount of photoinitiator.

(Problems to be Solved by the Invention) Since polymeric materials are used in various natural environments, their weather resistance is important. Causes of deterioration include heat, light, moisture, microorganisms, and contaminated air, but deterioration due to moisture is a problem along with thermal deterioration and photodeterioration, which progress deterioration due to autoxidation reactions. .

When a functional group susceptible to hydrolysis, such as an ester bond, is lost in a polymer structure, the polymer gradually undergoes hydrolysis under high humidity, causing a change in the chemical structure and a decrease in physical properties, leading to deterioration. In the above polyene-4 lithiol polymer, when a polyene-polythiol containing an ester bond is used, such as diallyl phthalate and trimethylolpropane tri-β-mercaptopropionate, which are listed in Japanese Patent Publication No. 47-3269, Under high humidity conditions, phenomena such as softening and decrease in strength may occur.

(Means for solving the problem) Based on the above facts, by using polyenes and polythiols that do not have ester bonds, it is possible to produce a polymer product that does not hydrolyze and soften even under high temperature and high humidity, that is, a cured product. Invented a curable composition.

That is, the photocurable composition of the present invention has the following (t), (
It contains each component of (2) and (3), and for a total of 1100 parts by weight of components (1) and (2), (3)
It is characterized by containing the component 'kO, 05 to 5 times ts.

Kyl group, substituted alkyl group, hydrogen atom, fluorine atom, chlorine atom, bromine atom, aryl group, substituted aryl group, alkoxy group! I'iit-substituted alkoxy group, Y is +C
H, -q (n is 0 or an integer from 1 to 10 a), JOCHJ
(p is an integer from 1 to 1°) or -o4cn, ) (q
is an integer from 1 to 10), and X is an atomic group capable of bonding with Y and having all m functional groups. ](2)
A polythiol having no ester bond and having an average molecular weight in the range of 50 to 15,000 (however, tXw, x
is an integer of 1 to 5, A is an oxygen atom or a sulfur atom, R' is a polyvalent organic residue, and y is an integer of 1 to 2. (3) Photoinitiator More specifically, examples of the polyenes mentioned in (1) above include divinylbenzene, divinyltoluene, triallyl cyanurate, triallyl isocyanurate, and tetraallyloxyethane.

Nine, the polythiol that is the component (2) includes diglycol dimercaptan, triglycol somercaptan, tetraglycol dimercaptan, thiodiglycol somercaptan, tetraglycol dimercaptan,
Examples include thiotetraglycol dimercaptan and polythiol commercially available from Diamond Jamrock Co. under the trade name DION3-800LC, but are not limited to these polyvalent thiols. Particularly preferable ones have a viscosity of 10 to 10.0OO at 25°C.
It is from CpS.

(3) Photoinitiators include benzophenone, p-methoxybenzophenone, 4,4-bisdimethylaminobenzophenone, xanthone, thioxanthone,
Chlorothioxanthone, m-chloroacetone, propiophenone, anthranonone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzyl, benzyl dimethyl ketal, acetophenone, 2.2-jethoxyacetophenone, 2-hydroxy Examples include, but are not limited to, 2.2-1' methylacetophenone.

The preferred ratio of each component of the composition of the present invention is polyene 2
5 to 75 parts by weight, 25 to 75 parts by weight of I-Liteol, and 0.05 to 5 parts by weight of photoinitiator per 100 parts by weight of the total amount of polyene and polythiol.

The composition of the present invention contains the above (1), (2), and (3) as essential components, and optionally includes antioxidants, chelating agents, hardening accelerators, dyes, pigments, and fillers. Additives such as a thixotropy agent, an antistatic agent, a plasticizer, a surfactant, a silane coupling agent, a viscosity modifier, and an adhesive can be added.

The composition of the present invention is easily cured by irradiation with actinic light, such as ultraviolet light. The cured product is stable even under high temperature and high humidity conditions, and will not soften even if left for a long time under these conditions.

(Example) Examples of the present invention are shown below. All parts are expressed by weight.

Example 1 (1) Triallylisocyanide 55 parts (2) Diglycol dimercaptan 45 parts (3) Benzyl dimethyl ketal 0.5 part After mixing the above compounds evenly, the mixture was placed in a 25φ x 5 (m) polyethylene cup. Filled with 400W ultraviolet rays for 30 minutes! It was irradiated for 30 minutes at a distance of The obtained cured product was left for 40 days at a temperature of 70° C. and a humidity of 80%, and the hardness was compared with the hardness immediately after curing.

The results are shown in Table 1.

Example 2 (1) Triallylisocyanudo 47 parts (2
) Triglycol dimercaptan 53 parts (3) Benzyl dimethyl ketal 0.5 part After uniformly mixing the above compounds, the same operation as in Example 1 was performed and the change in curing was measured. The results are shown in Table 1.

Comparative Example 1 (1) 41 parts of triallyl isocyanurate (
2) Trimethylolpropane tris → thioglycolate) 59 parts (3) Benzyl dimethyl ketal
After mixing 0.5 parts of the above compound with gold, the same operation as in Example 1 was carried out, and the change in hardness was measured. The results are shown in Table 1.

Table 1 Change in hardness of cured product Example 3 Using the mixture of Example 2 (sample A), pour it into a flat mold and place it under a 400W ultraviolet lamp at a distance of 30cWL for 30 minutes.
A sheet was created by irradiating for 0 minutes. Using this sheet, a JIS standard 7113 two-bow dumbbell sample was prepared. The obtained cured product (dumbbell sample) was left for 20 days at a temperature of 70°C and a humidity of 80%, and then a tensile test was conducted to determine the strength retention rate [(strength after standing/strength immediately after curing)
100 (%)] was calculated. Also, as a comparison sample (
1) triallylisocyanurate) 32m, (2)) lis-2- and droxyethyl isocyanurate-tris-β
- Dumbbell (sample B) taken from 68 parts of mercadetodelobionate and (3) 0.5 parts of benzyl dimethyl ketal
I created it and submitted it for testing. The results are shown in Table 2.

Table 2 Tensile strength of cured product (effects of the invention) As described above, the cured product obtained from the photocurable composition of the present invention exhibits excellent weather resistance even under high temperature and high humidity conditions. It can also be used in

Patent applicant: Denki Kagaku Kogyo Co., Ltd. Procedural amendment August 19, 1986

Claims (1)

[Scope of Claims] Contains each of the following components (1), (2), and (3), where component (3) is contained per 100 parts by weight of the total amount of components (1) and (2). A photocurable composition containing 0.05 to 5 parts by weight of. (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Polyene that does not have an ester bond [However, m
is an integer from 2 to 6, R_1, R_2 and R_3 are an alkyl group, a substituted alkyl group, a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an aryl group, a substituted aryl group, an alkoxy group or a substituted alkoxy group, Y is -(CH_
2) -_n (n is 0 or an integer from 1 to 10), -(OCH
_2) -_p (P is an integer of 1 to 10) or -O-(CH
_2)-_q (q is an integer from 1 to 10), and
is an atomic group capable of bonding with Y and having m functional groups. ] (2) General formula HS-(C_tH_2_t-A)-_wC_xH_2_
x-SH or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and the average molecular weight is in the range of 50 to 15,000.
x is an integer from 1 to 5, A is an oxygen atom or a sulfur atom, R' is a polyvalent organic residue, and y is an integer from 1 to 2.
is an integer. ) (3) Photoinitiator