Abstract: The present invention provides a curable polymethylsilsesquioxane composition that uses polymethylsilsesquioxane obtained from inexpensive precursors and that provides a hard, scratch-resistant, highly corrosion-resistant, water-repellent, and transparent cured film. The curable polymethylsilsesquioxane composition of the invention includes a polymethylsilsesquioxane having the general formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.mand a predetermined number-average molecular weight, Mn, from 380 to 2,000, wherein m and n are positive numbers that provide the predetermined Mn, with the proviso that the value of m/(m+n) is less than or equal to 0.152/(Mn.times.10.sup.-3)+0.10 and greater than or equal to 0.034/(Mn.times.10.sup.-3) and 10 to 250 weight parts colloidal silica.

Abstract: This invention relates to a silicone release coating comprising (A) an organopolysiloxane having at least two crosslinkable carbon-carbon double bonds in each molecule, (B) an organopolysiloxane having at least two Si-bonded hydrogen atoms in each molecule, (C) a silylated polymethylsilsesquioxane and (D) platinum catalyst. The silicone release coating compositions of this invention can further comprise an inhibitor. The silicone release coating compositions of this invention do not decline in release resistance due to release paper aging or release liner aging.

Abstract: An alkenyl-functional silylated polymethylsilsesquioxane that contains no more than 0.12 residual silanol per Si atom and is obtained by silylating the silanol in starting polymethylsilsesquioxane. The starting polymethylsilsesquioxane has a predetermined number average molecular weight, Mn, from 380 to 2,000 and is represented by the general formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.mwherein m and n are positive numbers that provide the predetermined Mn, with the proviso that the value of m/(m+n) is less than or equal to 0.152/(Mn.times.10.sup.-3)+0.10 and greater than or equal to 0.034/(Mn.times.10.sup.-3). The alkenyl-functional silylated polymethylsilsesquioxane has the formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.m-k (CH.sub.3 Si(OSiR.sup.1 R.sup.2 R.sup.3)O.sub.2/2).sub.kwherein k is a positive number smaller than A, (m-k/(m+n) is less than or equal to 0.12, and R.sup.1, R.sup.2 and R.sup.

Abstract: A hydrogen-functional silylated polymethylsilsesquioxane that contains no more than 0.12 residual silanol per Si atom and is obtained by silylating the silanol in starting polymethylsilsesquioxane. The starting polymethylsilsesquioxane has a predetermined number average molecular weight, Mn, from 380 to 2,000 and is represented by the general formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.mwherein m and n are positive numbers that provide the predetermined Mn, with the proviso that the value of m/(m+n) is less than or equal to 0.152/(Mn.times.10.sup.-3)+0.10 and greater than or equal to 0.034/(Mn.times.10.sup.-3). The hydrogen-functional silylated polymethylsilsesquioxane has the formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.m-k (CH.sub.3 Si(OSiR.sup.1 R.sup.2 R.sup.3)O.sub.2/2).sub.kwherein k is a positive number smaller than m, (m-k/(m+n) is less than or equal to 0.12, and R.sup.1, R.sup.2, and R.sup.

Abstract: A silylated polymethylsilsesquioxane, that contains no more than 0.12 residual silanol per Si atom and has a predetermined number average molecular weight from 380 to 2,000 is obtained by silylating the silanol in a starting polymethylsilsesquioxane with the formula(CH.sub.3 SiO.sub.3/2).sub.n (CH.sub.3 Si(OH)O.sub.2/2).sub.mwherein m and n are positive numbers that provide the specified molecular weight and 0.034/(M.times.10.sup.-3).ltoreq.m/(m+n).ltoreq.0.152/(M.times.10.sup.-3)+ 0.10. The silylated polymethylsilsequioxanes of the present invention exhibit compatibility with silicone polymers, e.g., polydimethylsiloxanes. As a consequence, the silylated polymethylsilsesquioxanes of the invention can be used in a wide range of applications as, for example, a reinforcing filler for rubbers.

Abstract: Methods are disclosed for the blending of inherently incompatible polymer systems to provide compositions comprising (i) 1 to 99.99 percent by weight of a diorganopolysiloxane; and (ii) 0.01 to 99 percent by weight of an organopolysiloxane-grafted rigid linear aromatic polymer selected from the group consisting of organopolysiloxane-grafted polyimide and organopolysiloxane-grafted polybenzobisoxazole.

Abstract: There is disclosed a novel organopolysiloxane-grafted polybenzobisoxazole and a method for preparing the functional organopolysiloxane-grafted polybenzobisoxazoles using a phthaloyl halide-functional organopolysiloxane.