Organopolysiloxane composition with filler

A composition comprising:

• a) from 2 to 50 weight percent of a first polyorganosiloxane having degree of polymerization in the range of from 5 to 200 and a DH concentration in the range of 60 to 100 mole percent;
• b) from 10 to 90 weight percent of a second polyorganosiloxane functionalized with at least two groups which are either ethylenically unsaturated groups or OH groups or a combination thereof;
• and having a degree of polymerization in the range of from 50 to 2000;
• wherein the concentrations of the first and the second polyorganosiloxanes are based on the weights of the first and the second polyorganosiloxanes;
• c) from 0.1 to 20 weight percent of a blowing agent, which is a C1-C8-alcohol, C1-C8-diol, a benzyl alcohol, HO—(CH2CHRO)z—H, a polyorganosiloxane functionalized with at least one OH group and having a degree of polymerization in the range from 1 to 15, or water, based on the concentration of the first and the second polyorganosiloxanes and the blowing agent;
• where R is H, methyl, or ethyl, and z is from 2 to 5;
• d) from 30 to 50 weight percent of one or more fillers, based on the weight of composition, wherein the one or more fillers are selected from the group consisting of metals, metal oxides, metal hydroxides, metal acetates, metal carbides, metal oxycarbides, metal carbonates and bicarbonates, metal hydroxycarbonates, metal sulfates, metal chlorides, metal nitrides, metal nitrates, metal silicides, metal silicates;
• and
• e) a catalytic amount of a catalyst that promotes the reaction between the first and the second polyorganosiloxanes;
• and the first polyorganosiloxane and the blowing agent;
• wherein the mole-to-mole ratio of DH groups in the first polyorganosiloxane to the ethylenically unsaturated and/or OH groups of the second polyorganosiloxane is in the range of from 1.7:1 to 20:1.