摘要:
Fluorosilicone heat cured rubber compositions are prepared using a chain modifier mixture comprising vinyl terminated polysiloxanes and silanol terminated siloxanes which allow vinyl-on-chain-ends functionality to easily crosslink unhindered by perfluoroalkyl groups.
摘要:
A treatment for finely divided silica reinforcing fillers is provided which utilizes low temperature and hydroxy or alkoxy containing diorganopolysiloxane as the treating agent. The treatment of fillers in this manner facilitates the manufacture and incorporation into silicone rubbers.
摘要:
There is provided a method for preventing premature curing of curable silicone compositions comprising admixing with said curable composition an amount of Lewis base effective to neutralize any Lewis acid present therein.
摘要:
A treatment for finely divided silica reinforcing fillers is provided which comprises heating the silica filler in the presence of a fluoroalkyl-functional diorganopolysiloxane treating agent. The treated fillers are especially compatible with fluorosilicone gums, and fluorosilicone rubbers made using said fillers exhibit improved mechanical properties, especially tear strength and compression set.
摘要:
A heat curable oil extended silicone elastomer composition and the cured silicone elastomers derived therefrom which exhibit improved melt flow and improved tear resistance at high filler loadings. A preferred composition comprises in admixture, a silarylenesiloxane polydiorganosiloxane block copolymer, a dimethylsilicone oil bearing vinyl-type unsaturation, a filler and a catalyst.
摘要:
A solution comprising a composition and a volatile silicone solvent overcomes the environmental disadvantages associated with volatile organic compounds. The invention particularly provides for a primer composition for bonding silicone elastomers to metals that is free of volatile organic compounds comprises an epoxy alkoxy silane, a titanium ortho alcoholate or ortho ester, a silicon ortho alcoholate or ortho ester and a volatile silicone compound.
摘要:
A thin fluorosilicone elastomer coating which prevents oil weepage problems with silicone rubber gaskets wherein the fluorosilicone elastomer coating contains a vinyl-containing fluorosilicone polymer cured with a hydrogen-containing siloxane/platinum group hydrosilation catalyst curing system used in combination with a peroxide curing agent.
摘要:
In a heat curable silicone rubber composition comprising a polydiorganosiloxane base polymer and a curing catalyst, the improvement comprising an effective amount of co-curing agent. Preferably, the co-curing agent has the general formula ##STR1## where R is H or a C.sub.1-5 alkyl radical, R.sup.1 is a C.sub.1-5 alkylene radical, each R.sup.2 is independently selected from H and CH.sub.3, R.sup.3 is H or CH.sub.3, n equals 0 or 1, and m is an integer from 3 to 6, inclusive.
摘要:
There is provided a process for producing low molecular weight silanol end-stopped diorganopolysiloxanes containing an average of 3 to 10 diorganosiloxy units and averaging 5 diorganosiloxy units comprising contacting a cyclic trimer of the formula:(R.sup.2 SiO).sub.3where R.sup.2 is a halogenated monovalent hydrocarbon radical and R is selected from the class consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals with a mixture comprising an aprotic solvent and water and separating the desired product after the hydrolysis.
摘要:
Sodium fluorosilanolate catalyst is disclosed which has improved effectiveness as a catalyst to produce fluorosilicone polymer and which at the same time improves fluorosilicone polymer purity.