Foamable organosiloxane compositions curable to silicone foams having improved adhesion

A method of improving the adhesion of a silicone foam to a substrate, said method comprising the steps of:

• (I) preparing a foamable, curable organosiloxane composition comprising:
• (A) 100 parts by weight of a polyorganosiloxane containing an average of at least two alkenyl radicals per molecule and having a viscosity within a range of about 0.03 Pa.s to 100 Pa.s at 25.degree. C.;
• (B) an organohydrogensiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule;
• (C) a blowing agent;
• (D) a catalytically effective amount of a platinum group metal catalyst;
• and
• (E) an adhesion promoter comprising:
• i) 0.01 to 10 parts by weight, per 100 parts by weight of Component (A), of an epoxy-functional compound;
• ii) 0.01 to 5 parts by weight, per 100 parts by weight of Component (A), of a hydroxyl-functional compound comprising at least one hydroxy group and in the same molecule at least one alkenyl group;
• iii) 0.1 to 5 parts by weight, per 100 parts by weight of Component (A), of a tetraalkylorthosilicate;
• iv) 0.01 to 1 parts by weight, per 100 parts of component (A), of a organotitanate;
• and
• v) 0.0005 to 1 part by weight of a catalyst selected from a group consisting of compounds of aluminum and compounds of zirconium;
• wherein the sum of the average number of silicon-bonded hydrogen atoms per molecule of component (B) and the average number of silicon-bonded alkenyl groups per molecule in component (A) is greater than 4;
• (II) applying the foamable, curable composition to the substrate;
• (III) allowing the foamable, curable composition to form a foam;
• and
• (IV) allowing the foamable, curable composition to cure.