Room-temperature vulcanized one-component dealcoholized silicone rubber sealant and preparation method thereof

Abstract

The invention discloses a room-temperature vulcanized one-component dealcoholized silicone rubber sealant and a preparation method thereof. The sealant comprises the following components in parts by weight: 100 parts of (A) alpha, omega-dihydroxyl polydimethylsiloxane, 10-30 parts of (B) simethicone, 5-10 parts of (C) a cross-linking agent, 1-5 parts of (D) a silane coupling agent, 50-150 parts of (E) reinforcing filler, 0.5-3 parts of (F) a catalyst and 0.5-2 parts of (G) storage stabilizer. Due to addition of the silane coupling agent containing various active functional groups, the defect that common dealcoholized silicone rubber sealant cannot have good adhesion performance and good storage performance at the same time is overcome, and storage performance is not affected when the adhering performance is improved. In addition, as the sealant uses the titanate catalyst with low yellowing property, the sealant has excellent yellowing resistance, the defect that common dealcoholized silicone rubber sealant is easy to yellow is overcome, and the sealant provided by the invention can be widely applied to adhering and sealing in the industries such as electronics, automobiles and home appliances.

Description

technical field [0001] The invention relates to a silicone rubber sealant and a preparation method thereof, in particular to a room temperature vulcanized one-component dealcoholized silicone rubber sealant and a preparation method thereof. Background technique [0002] One-component room temperature vulcanized silicone rubber sealant has been widely used in electronics, automobiles, home appliances, construction and other industries due to its advantages of wide temperature resistance range, good weather resistance, excellent insulation performance and convenient operation, while dealcoholized silicone rubber Due to the advantages of environmental protection, no irritating smell, and no corrosion to the bonding substrate, the sealant has become one of the most widely used varieties of silicone rubber sealants. The general dealcoholized silicone rubber sealant is composed of base rubber, filler, alcohol type crosslinking agent, titanate catalyst and adhesion promoter. Dealc...

AI Technical Summary

Problems solved by technology

Dealcoholized silicone rubber sealant has low odor and meets environmental protection requirements, but its storage performance and adhesive performance are poor. The storage performance can be improved by adding hydroxyl scavenger, but it is difficult to improve the adhesive performance

Generally, the adhesiveness of silicone rubber sealants is mainly improved by adding silane coupling agents. Aminosilane coupling agents are widely used in other types of silicone rubber sealants due to their good adhesion, but they are used in titanic acid Although the adhesive performance of the sealant can be improved when the ester dealcoholization system is used, due to the high reactivity of titanate, it is easy to react with aminosilane during storage, resulting in a serious decline in curing performance after storage

In order to maintain better storage stability, it is necessary to reduce the amount of aminosilane coupling agent, or to avoid the use of amino coupling agent, use other neutral silane coupling agent such as epoxy silane as adhesion promoter, but this It will also cause the sealant to reduce the adhesion of some low surface energy materials, and the adhesion performance will deteriorate

Another disadvantage of dealcoholized silicone rubber sealant is that it is prone to yellowing, which will gradually turn yellow after a long time of use, which limits its use in some occasions where appearance is important

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