Unlock instant, AI-driven research and patent intelligence for your innovation.

Heat-curable silicone rubber composition

a technology of silicone rubber and composition, applied in the field of heat-curable silicone rubber composition, can solve the problems of inability to exhibit sufficient anti-static effects, difficult to use the composition as a cover for portable music players, portable game machines, cell phones and controllers, etc., and achieves poor compatibility, high anti-static properties, and imparts stably anti-static properties

Inactive Publication Date: 2014-09-18
MOMENTIVE PERFORMANCE MATERIALS JAPAN LLC
View PDF8 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The solution provides a heat-curable silicone rubber with sustained antistatic properties after secondary vulcanization at high temperatures and maintains transparency, suitable for applications like portable device covers and coatings, while using smaller amounts of ionic substances for faster and more effective results compared to solid lithium salts.

Problems solved by technology

The compositions using the polyether compound, however, have a problem that the cured products thereof have a white turbidity because of a poor compatibility between the silicone polymer and the polyether-based antistatic agent.
Therefore, it is difficult to use the composition as covers for portable music players, portable game machines, cell phones and controllers of game machines; silicone rubber molds used for producing duplicates by using a urethane resin; and silicone rubber materials used for coating a cloth with the silicone rubber, all of which require a higher transparency in the use thereof.
The compositions using the polyether compound also have a problem that the polyether compound thermally decomposes at high temperatures and, thus, sufficient antistatic effects cannot be exhibited.
It is important for antistatic products to exhibit antistatic effects on their surfaces, but the solid substance has drawbacks in that it takes time until it exhibits the effect.
Furthermore, the lithium salt has quality drawbacks such that differences easily occur in the dispersion state and that it is difficult to obtain a stable quality.
However, a dimethyl silicone polymer is originally non-polar and has a low solubility constant (SP value) of 14.9 (MPa)1 / 2, and thus has a very low compatibility with the ionic liquid which has a high compatibility with a polymer having a high SP value such as urethane, epichlorohydrin, acrylonitrile butadiene or chloroprene.
It is difficult therefore to stably add the ionic liquid to the silicone rubber, and even if the ionic liquid is added to the rubber, much of it bleeds immediately on the surface of the rubber, and the effect cannot be maintained.
Furthermore, a large amount of the ionic liquid is used, and thus it is not suitable for commercial use, even though an expensive ionic liquid is used.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0031]30 parts of dry silica (manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 150 m2 / g, and 3 parts of polydimethylsiloxane (average degree of polymerization: 10) having terminal silanol groups were mixed with 100 parts of a vinyl group-containing polydimethylorganosiloxane having an average degree of polymerization of 5000, and having 0.20% by mole of methylvinylsiloxane units, and the mixture was heat-mixed over two hours at 150° C. to thereby obtain a silicone rubber base compound. Next, 10 ppm of N-butyl-3-methylpyridinium•bis(trifluoromethane-sulfonyl)imide, which was water-insoluble, had a decomposition temperature of 290° C., and was liquid at ordinary temperatures, and 0.02 part of dry silica (manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 150 m2 / g were added to 100 parts of the base compound, which was carried by the filler and was then mixed. After that, 1.0 part of a vulcanizing agent (TC-8 in which 2,5-dimethyl-2,5...

example 2

[0032]A rubber sheet was obtained in the same manner as in Example 1, except that 1-butyl-1-methylpyrrolidinium•bis-(trifluoro-methanesulfonyl)imide, which was water-insoluble, had a decomposition temperature of 420° C. and was liquid at ordinary temperatures, was used instead of N-butyl-3-methylpyridinium•bis(trifluoromethanesulfonyl)imide.

example 3

[0033]A rubber sheet was obtained in the same manner as in Example 1, except that diallyldimethylammonium•bis(trifluoromethane-sulfonyl)imide, which was poorly water-soluble, had a decomposition temperature of 270° C. and was liquid at ordinary temperatures, was used instead of N-butyl-3-methylpyridinium•bis(trifluoromethane-sulfonyl)imide.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
hardnessaaaaaaaaaa
specific surface areaaaaaaaaaaa
specific surface areaaaaaaaaaaa
Login to View More

Abstract

The present invention provides a heat-curable silicone rubber composition having antistatic properties, even after secondary vulcanization at high temperatures. Specifically disclosed is a heat-curable silicone rubber composition which is obtained by adding 0.05 to 1000 ppm of (B) a poorly water-soluble or water-insoluble ionic substance whose anionic component is bis(trifluoromethanesulfonyl)imide, to 100 parts by weight of (A) a heat-curable silicone rubber.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This is a continuation of prior U.S. application Ser. No. 12 / 735,083, which was the National stage of International Application No. PCT / JP2008 / 073962, filed Dec. 26, 2008.FIELD OF THE INVENTION [0002]The present invention relates to a heat-curable silicone rubber composition having high antistatic properties.BACKGROUND OF THE INVENTION[0003]Hitherto, antistatic rubber compositions using a polyether-based compound as an antistatic agent have been proposed (JP-B 62-15584). The compositions using the polyether compound, however, have a problem that the cured products thereof have a white turbidity because of a poor compatibility between the silicone polymer and the polyether-based antistatic agent. Therefore, it is difficult to use the composition as covers for portable music players, portable game machines, cell phones and controllers of game machines; silicone rubber molds used for producing duplicates by using a urethane resin; and silico...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): C08K5/3432C08K5/3415C08K5/41
CPCC08K5/3432C08K5/41C08K5/3415C08G77/06C08G77/20C08G77/24C08K5/43C08L83/04C08G77/04
Inventor IIJIMA, HIROYOSHITAKAHASHI, HIDEO
Owner MOMENTIVE PERFORMANCE MATERIALS JAPAN LLC