Filled silicone composition, in situ preparation and use thereof

摘要

Filled silicone composition, in situ preparation and use thereof are provided. The composition comprises a mixture of (A) an in situ-prepared treated silica, (B) an in situ-prepared (siloxane-alkylene)-endblocked polydiorganosiloxane, (c) a cure catalyst and (D) a crosslinker. Moreover, the composition can be used as adhesive, coating and sealant.

主权项

1. A filled silicone composition comprising a mixture of:
(A) an in situ-prepared treated silica; (B) an in situ-prepared (siloxane-alkylene)-endblocked polydiorganosiloxane (“SAE Polymer”); (C) a catalytically effective amount of a cure catalyst; and (D) a crosslinking effective amount of a crosslinker; wherein the composition is prepared by: treating an untreated silica with a treating effective amount of a treating agent in presence of an alkenyl-endblocked polydiorganosiloxane (“AE Polymer”) so as to produce a liquid silicone rubber master batch (“LSR MB”) comprising a mixture of the treated silica and the AE Polymer; converting the AE Polymer in the LSR MB with a converting effective amount of a SiH containing siloxane and a catalytically effective amount of a hydrosilation catalyst so as to produce a SiH converted polymer master batch (“SCP MB”) comprising a mixture of the treated silica and the SAE Polymer; and mixing the SCP MB with sufficient amounts of the cure catalyst and the crosslinker so as to produce the composition, and wherein the AE Polymer is an alkenyl-endcapped polydimethylsiloxane of formula (VE1):
CH2═CH—Si(CH3)2O—[Si(CH3)2O]n—Si(CH3)2—CH═CH2  (VE1), wherein n is an average number of from 100 to 1000, and a dynamic viscosity of from 100 to 100,000 milliPascal-seconds (mPa·s) when tested as described in ASTM D1084; the untreated silica has a surface area of from 200 to 400 square meters per gram (m2/g) and is from greater than 0 wt % to 35 wt % based on total weight of the composition; the weight/weight ratio of AE Polymer to untreated silica is from 60:40 to 90:10; and the SiH containing siloxane is of formula (SH1):
((C1-C3)alkoxy)3Si(C1-C4alkylene)Si(Rc)2OSi(Rc)2H  (SH1), wherein each Rc independently is (C1-C3)alkyl.