CN-121986128-A - Photocurable silicone composition

Abstract

The invention provides a photo-curing organic silicon composition, which is characterized by comprising (A) organopolysiloxane represented by the following general formula (1) [ chemical formula 1] (In the formula, n is an integer of 10 or more, R 1 is independently methyl or phenyl, and R 2 is a group represented by the following general formula (2)) [ chemical formula 2] (Wherein m is an integer of 0to 20, R 3 is independently a methyl group or a phenyl group, Z 1 is a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms, Z 2 is an oxygen atom or a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms, and a line with wavy lines represents a bond.) (B) an organic compound having a (meth) acryloyl group and an epoxy group in 1 molecule and having no alkoxysilyl group, (C) a photo radical polymerization initiator, and (D) a silica powder having a BET specific surface area of 100m 2 /g or more, and the ratio of the methyl group bonded to a silicon atom to the phenyl group bonded to a silicon atom in the component (A) is in the range of 97:3 to 80:20. Thus, a photocurable silicone composition which gives a cured product having excellent surface curability and deep curability and little compression set is provided.

Inventors

• KIMURA SHINZO

Assignees

• 信越化学工业株式会社

Dates

Publication Date

20260505

Application Date

20240826

Priority Date

20231011

Claims (5)

1. 1. A photocurable silicone composition characterized by comprising, Comprises the following components (A) - (D); (A) An organopolysiloxane represented by the following general formula (1) in an amount of 100 parts by mass, [ Chemical formula 1] Wherein n is an integer of 10 or more, R 1 is independently methyl or phenyl, R 2 is a group represented by the following general formula (2), [ Chemical formula 2] Wherein m is an integer of 0 to 20, R 3 is independently methyl or phenyl, Z 1 is a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms, Z 2 is an oxygen atom or a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms, the line with wavy lines represents a bond, (B) 0.1 to 10 parts by mass of an organic compound having a (meth) acryloyl group and an epoxy group in 1 molecule and not having an alkoxysilyl group, (C) 0.1 to 10 parts by mass of a photo radical polymerization initiator, and (D) 0.1 to 50 parts by mass of silica powder having a BET specific surface area of 100m 2 /g or more, The ratio of the methyl group bonded to the silicon atom to the phenyl group bonded to the silicon atom in the component (A) is in the range of 97:3 to 80:20.
2. 2. The photocurable silicone composition according to claim 1, wherein the component (B) is an organic compound represented by the following general formula (3), [ Chemical formula 3] In the formula, R 4 is a hydrogen atom or a methyl group, and Z 3 is a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms.
3. 3. The photocurable silicone composition according to claim 1, wherein the component (D) is a silica powder surface-treated with a (meth) acryl-containing organosilicon compound.
4. 4. A liquid gasket comprising the photocurable silicone composition according to any one of claims 1 to 3.
5. 5. The cured product of a photocurable silicone composition according to any one of claims 1 to 3, which has a compression set of 30% or less as measured after compression at 25% for 100 hours at 120 ℃.

Description

Photocurable silicone composition Technical Field The present invention relates to a photocurable silicone composition which gives a cured product excellent in surface curability and deep curability and having a low compression set, and which is suitable as a liquid gasket material. Background The simplification and cost reduction in the manufacturing process are compatible with the trend of energy conservation which pays attention to environmental protection, and the process is actively promoted in various fields. In particular, curable elastomers used for electronic parts and structural parts require enormous energy, time and equipment for curing, which often accompanies a high-temperature heating process, and thus improvement is desired. In addition, the improvement of the heating process is significant not only in terms of energy and cost, but also in terms of manufacturing technology without damaging other components. In recent years, in order to solve these problems, a photocurable composition has been attracting attention. The photocurable composition contains a photoinitiator activated by irradiation with light, particularly ultraviolet rays, and thus undergoes polymerization or crosslinking reaction, and is usually cured in a short time of several tens of seconds to several tens of minutes. Therefore, other parts are not easily damaged, and a large apparatus is not required. Recently, ultraviolet irradiation devices and the like using LEDs have also been developed, and have become an excellent manufacturing process. To date, silicone compositions have been reported which use photoradical polymerization as a crosslinking system. The composition has the characteristics of high reaction speed due to high reactivity and curing in a short time, and on the contrary, the free radical has very short service life and is easily inactivated by oxygen and the like. As a result, the curability of the surface of the silicone composition in contact with air may be significantly reduced. On the other hand, deep curability is also important, and the silicone composition needs to have a certain transparency in order to allow light to reach the inside. Attempts are currently being made to use such photocurable compositions in liquid gasket materials. Among them, a method called CIPG is suitable for a small number of gaskets of various types, and is a method of easily producing a cured product by light irradiation. The CIPG is a method of forming a gasket material on one flange and then pressing the other flange to ensure sealing. Therefore, even if the gasket material is compressed for a long period of time, the restoring force cannot be reduced. That is, it is desirable to have a low compression set. As a photocurable composition having a low compression set characteristic, a composition comprising an ethylene polymer having a (meth) acryloyl group and a compound having an ethylenically unsaturated group has been proposed, but has been insufficient in terms of flexibility and durability as compared with silicone rubber (patent document 1). In order to have 2 characteristics of good surface curability and low compression set, there has been proposed a silicone composition containing fumed silica surface-treated with a silicone compound having a (meth) acryloyl group and a silicone compound having no (meth) acryloyl group (patent document 2). However, the condensation reaction proceeds simultaneously to improve the surface curability, which results in a problem of lowering the preservability of the composition. Prior art literature Patent literature Patent document 1 International publication No. 2007/004584 Patent document 2 Japanese patent application laid-open No. 2018-058946 Disclosure of Invention Technical problem to be solved by the invention The present invention has been made in view of the above circumstances, and an object thereof is to provide a photocurable silicone composition which gives a cured product having excellent surface curability and deep curability and little compression set. Technical means for solving the problems In order to solve the above problems, the present invention provides a photocurable silicone composition comprising, Comprises the following components (A) - (D); (A) An organopolysiloxane represented by the following general formula (1) in an amount of 100 parts by mass, [ Chemical formula 1] (In the formula, n is an integer of 10 or more, R １ is independently methyl or phenyl, and R 2 is a group represented by the following general formula (2)) [ Chemical formula 2] (Wherein m is an integer of 0 to 20, R 3 is independently methyl or phenyl, Z 1 is a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms, Z 2 is an oxygen atom or a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms, and a line with a wavy line represents a bond.) (B) 0.1 to 10 parts by mass of an organic compound having a (meth) acryloyl group and an epoxy grou