Abstract: An injection moldable composition, comprising: A) a silicone resin (I) [R13SiO1/2]a[R2R3SiO2/2]b[SiO4/2]c, wherein R1, R2, and R3 are hydrocarbyl, hydrocarbyloxy, or hydroxyl, at least one of R2 or R3 is alkenyl, subscripts a, b, and c are each >0 and a+b+c=1, B) 0 to 90% (w/w), based on the weight of A) and B), of a silicone resin (II) [R43SiO1/2]d[SiO4/2]e wherein R4 is hydrocarbyl, hydrocarbyloxy, or hydroxyl, at least one of R4 is alkenyl, subscripts d and e are each >0, and d+e=1, C) a siloxane polymer having formula (III), [R53SiO1/2]fR6R7SiO2/2]g. wherein R5-7 are hydrocarbyl or hydroxyl, at least one of R5-7 is alkenyl, subscripts f and g are each >0, and f+g=1, D) a silicone crosslinker having at least two silicon-bonded hydrogen atoms per molecule, and E) a hydrosilylation catalyst, wherein the ratio of silicon-bonded hydrogen atoms to carbon-carbon double bonds is from 1.2 to 2.2.

Abstract: A curable silicone composition comprising (A) an alkenyl-containing organopolysiloxane comprising (A-1) a dialkylpolysiloxane that has an average of at least two alkenyl groups in each molecule), and (A-2) an alkenyl-containing, resin-form organopolysiloxane that comprises the SiO4/2 unit, R12R2SiO1/2 unit, and R13SiO1/2 unit; (B) an organopolysiloxane that has an average of at least three silicon-bonded hydrogen atoms in each molecule, wherein component (B) is an organopolysiloxane comprising (B-1) an organopolysiloxane that contains at least 0.7 mass % silicon-bonded hydrogen and that comprises SiO4/2 units and HR32SiO1/2 units in a ratio ranging from 1.50 to 2.50 moles of HR32SiO1/2 units per 1 mole of SiO4/2 units, at 50 to 100 mass % of component (B), and (B-2) a straight-chain organopolysiloxane that contains at least 0.3 mass % silicon-bonded hydrogen, at 0 to 50 mass % of component (B); and (C) a hydrosilylation reaction catalyst.

Abstract: An injection moldable composition, comprising: A) a silicone resin (I) [R13SiO1/2]a[R2R3SiO2/2]b[SiO4/2]c, wherein R1, R2, and R3 are hydrocarbyl, hydrocarbyloxy, or hydroxyl, at least one of R2 or R3 is alkenyl, subscripts a, b, and c are each >0 and a+b+c=1, B) 0 to 90% (w/w), based on the weight of A) and B), of a silicone resin (II) [R43SiO1/2]d[SiO4/2]e wherein R4 is hydrocarbyl, hydrocarbyloxy, or hydroxyl, at least one of R4 is alkenyl, subscripts d and e are each >0, and d+e=1, C) a siloxane polymer having formula (III), [R53SiO1/2]fR6R7SiO2/2]g. wherein R5-7 are hydrocarbyl or hydroxyl, at least one of R5-7 is alkenyl, subscripts f and g are each >0, and f+g=1, D) a silicone crosslinker having at least two silicon-bonded hydrogen atoms per molecule, and E) a hydrosilylation catalyst, wherein the ratio of silicon-bonded hydrogen atoms to carbon-carbon double bonds is from 1.2 to 2.2.

Abstract: A hydrosilylation process is used to prepare a polyorganosiloxane having clustered functional groups at the polyorganosiloxane chain terminals. The ingredients used in the process include a) a polyorganosiloxane having an average of at least 2 aliphatically unsaturated organic groups per molecule, b) a polyorganohydrogensiloxane having an average of 4 to 15 silicon atoms per molecule and at least 4 silicon bonded hydrogen atoms for each aliphatically unsaturated organic group in ingredient a), c) a reactive species having, per molecule at least 1 aliphatically unsaturated organic group and 1 or more curable groups; and d) a hydrosilylation catalyst. The resulting clustered functional polyorganosiloxane is useful in a curable silicone composition for electronics applications.

Abstract: A hydrosilylation process is used to prepare a polyorganosiloxane having clustered functional groups at the polyorganosiloxane chain terminals. The ingredients used in the process include a) a polyorganosiloxane having an average of at least 2 aliphatically unsaturated organic groups per molecule, b) a polyorganohydrogensiloxane having an average of 4 to 15 silicon atoms per molecule and at least 4 silicon bonded hydrogen atoms for each aliphatically unsaturated organic group in ingredient a), c) a reactive species having, per molecule at least 1 aliphatically unsaturated organic group and 1 or more curable groups; and d) a hydrosilylation catalyst. The resulting clustered functional polyorganosiloxane is useful in a curable silicone composition for electronics applications.