A process for end capping and chain extending silanol terminated polydiorganosiloxanes with a mixture of one or more alkylacetoxydialkoxysilanes and one or more alkyldiacetoxyalkoxysilanes. The resulting capped polymeric material may be utilised as a polymer in e.g. a one-part alkoxy sealant composition such as, for example, an alkoxy low modulus clean (non-staining) or clear sealant composition.

A single vessel process for producing heteroleptic POSS compositions. The process involves the addition of two or more different organosilanes into a reactor containing a solvent. A base catalyst is added to the reactor to hydrolytically assemble the POSS cage core and statistically distribute the organic groups from the organosilanes around the periphery of the POSS cage core. An acid is then added to neutralize or quench the base catalyst. The product is washed and the remaining solvent is removed to recover the heteroleptic POSS. In some alternate embodiments, the product is filtered to recover the heteroleptic POSS. The heteroleptic POSS compositions produced by this process are able to provide an envelope of desirable effects. The heteroleptic POSS compositions may be used as additives for optimizing the performance attributes of coatings, biological materials, thermoplastics, thermoset, and gel polymer systems. The process also produces homoleptic POSS compositions with improved physical characteristics.

A single vessel process for producing heteroleptic POSS compositions. The process involves the addition of two or more different organosilanes into a reactor containing a solvent. A base catalyst is added to the reactor to hydrolytically assemble the POSS cage core and statistically distribute the organic groups from the organosilanes around the periphery of the POSS cage core. An acid is then added to neutralize or quench the base catalyst. The product is washed and the remaining solvent is removed to recover the heteroleptic POSS. In some alternate embodiments, the product is filtered to recover the heteroleptic POSS. The heteroleptic POSS compositions produced by this process are able to provide an envelope of desirable effects. The heteroleptic POSS compositions may be used as additives for optimizing the performance attributes of coatings, biological materials, thermoplastics, thermoset, and gel polymer systems. The process also produces homoleptic POSS compositions with improved physical characteristics.

One of purposes of the present invention is to provide an organopolysiloxane that has a low viscosity and allows a cured coating to achieve both high hardness and crack resistance, and provide a composition comprising the organopolysiloxane. An organopolysiloxane represented by the following average unit formula (1) and having a kinetic viscosity of 10 to 350 mm.sup.2/s at 25° C., wherein a proportion (%) of the number of silicon atoms in a unit represented by the following formula (1′) to a total number of silicon atoms in all siloxane units of the organopolysiloxane is 10% or less,

##STR00001##

wherein R.sup.1, R.sup.2, and R.sup.3 are, independently of each other, an unsubstituted or substituted, cyclic or non-cyclic alkyl group having 1 to 12 carbon atoms that may include an ether bond, or an unsubstituted or substituted aryl group having 6 to 12 carbon atoms, R.sup.4 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and a, b, c, d and e are numbers satisfying the equations 0.2≥a≥0, 1≥b>0, 0.75≥c≥0, 0.2≥d≥0 and 1≥e>0, provided that a+b+c+d=1.

One of purposes of the present invention is to provide an organopolysiloxane that has a low viscosity and allows a cured coating to achieve both high hardness and crack resistance, and provide a composition comprising the organopolysiloxane. An organopolysiloxane represented by the following average unit formula (1) and having a kinetic viscosity of 10 to 350 mm.sup.2/s at 25° C., wherein a proportion (%) of the number of silicon atoms in a unit represented by the following formula (1′) to a total number of silicon atoms in all siloxane units of the organopolysiloxane is 10% or less,

##STR00001##

wherein R.sup.1, R.sup.2, and R.sup.3 are, independently of each other, an unsubstituted or substituted, cyclic or non-cyclic alkyl group having 1 to 12 carbon atoms that may include an ether bond, or an unsubstituted or substituted aryl group having 6 to 12 carbon atoms, R.sup.4 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and a, b, c, d and e are numbers satisfying the equations 0.2≥a≥0, 1≥b>0, 0.75≥c≥0, 0.2≥d≥0 and 1≥e>0, provided that a+b+c+d=1.

An object of the present invention is to provide a polyorganosiloxane-containing graft copolymer powder capable of providing a resin composition and a molded article which are excellent in balance between colorability and mechanical properties such as impact resistance. The polyorganosiloxane-containing graft copolymer powder according to the present invention is a graft copolymer powder obtained by graft-polymerizing a mixture (B) of a vinyl monomer (b1) having an epoxy group and another vinyl monomer (b2) to a rubber (A) containing a polyorganosiloxane, wherein the content of the polyorganosiloxane (A1) contained in the rubber (A) is 12 to 50% by mass, the mass average particle diameter of the polyorganosiloxane-containing graft copolymer powder is 300 to 2000 nm, and the epoxy equivalent of the polyorganosiloxane-containing graft copolymer powder is 2500 to 7800 g/eq.

The present disclosure relates to self-healing siloxane elastomers. In particular, the present disclosure relates to self-healing siloxane elastomers comprising at least one siloxane polymer reversibly crosslinked to a second siloxane oligomer or polymer, the reversible cross-linked may be formed at ambient temperature.

The present disclosure relates to self-healing siloxane elastomers. In particular, the present disclosure relates to self-healing siloxane elastomers comprising at least one siloxane polymer reversibly crosslinked to a second siloxane oligomer or polymer, the reversible cross-linked may be formed at ambient temperature.

The present invention relates to aspartic acid ester-functional polysiloxanes, their use in the manufacture of curable compositions using polyisocyanate crosslinkers, in particular, in the manufacture of coating compositions, cured compositions obtained from said curable compositions and articles comprising the cured compositions.

The present invention relates to aspartic acid ester-functional polysiloxanes, their use in the manufacture of curable compositions using polyisocyanate crosslinkers, in particular, in the manufacture of coating compositions, cured compositions obtained from said curable compositions and articles comprising the cured compositions.