A subject matter of the invention is a molecularly imprinted polymer obtained by polymerization of a mixture comprising a silane, a tetra(C.sub.1-C.sub.4)alkyl orthosilicate, a porogenic solvent and a C.sub.14-C.sub.20 fatty acid. Cosmetic composition comprising such a polymer. Cosmetic method for preventing and/or treating dandruff of the scalp using such a polymer.

The invention relates to a crosslinkable composition X, comprising: at least one organopolysiloxane compound A comprising, per molecule, at least two C2-C6 alkenyl radicals bonded to silicon atoms; at least one organohydrogenopolysiloxane compound B comprising, per molecule, at least two hydrogen atoms bonded to an identical or different silicon atom; at least one catalyst C which is a complex corresponding to the following formula: [Co (L1)2] in which: the symbol Co represents cobalt at degree of oxidation II; the symbols L1, which may be identical or different, represent a ligand which is a -dicarbonylato anion or the enolate anion of a -dicarbonylated compound; optionally at least one adhesion promoter D; and optionally at least one filler E. The invention also relates to the use of the previously described catalyst C as silicone composition crosslinking catalyst, to a silicone composition crosslinking method, characterized in that it consists in heating the composition X to a temperature of between 70 and 200 C., and to the resulting crosslinked silicone material Y.

The invention relates to a crosslinkable composition X, comprising: at least one organopolysiloxane compound A comprising, per molecule, at least two C2-C6 alkenyl radicals bonded to silicon atoms; at least one organohydrogenopolysiloxane compound B comprising, per molecule, at least two hydrogen atoms bonded to an identical or different silicon atom; at least one catalyst C which is a complex corresponding to the following formula: [Co (L1)2] in which: the symbol Co represents cobalt at degree of oxidation II; the symbols L1, which may be identical or different, represent a ligand which is a -dicarbonylato anion or the enolate anion of a -dicarbonylated compound; optionally at least one adhesion promoter D; and optionally at least one filler E. The invention also relates to the use of the previously described catalyst C as silicone composition crosslinking catalyst, to a silicone composition crosslinking method, characterized in that it consists in heating the composition X to a temperature of between 70 and 200 C., and to the resulting crosslinked silicone material Y.

A process of producing a silicone polymer includes hydrolyzing/condensating one or more compound in the presence of a base, thereby producing a silicone polymer that has an organic acid content of 0.0001 to 0.03 parts by weight with respect to 100 parts by weight of the silicone polymer. The process for producing a silicone polymer makes it possible to inhibit an increase in the molecular weight of a silicone polymer during high-temperature concentration in the steps of producing a silicone polymer.

A process of producing a silicone polymer includes hydrolyzing/condensating one or more compound in the presence of a base, thereby producing a silicone polymer that has an organic acid content of 0.0001 to 0.03 parts by weight with respect to 100 parts by weight of the silicone polymer. The process for producing a silicone polymer makes it possible to inhibit an increase in the molecular weight of a silicone polymer during high-temperature concentration in the steps of producing a silicone polymer.

Impure gaseous hydrogen chloride from organochlorosilane hydrolysis is freed of impurities by first scrubbing with an organochlorosilane, which may be the same or different from the organochlorosilane(s) hydrolyzed, and then further scrubbing with chloromethane. The purified gaseous hydrogen chloride is preferably used in chlorosilane synthesis.

Impure gaseous hydrogen chloride from organochlorosilane hydrolysis is freed of impurities by first scrubbing with an organochlorosilane, which may be the same or different from the organochlorosilane(s) hydrolyzed, and then further scrubbing with chloromethane. The purified gaseous hydrogen chloride is preferably used in chlorosilane synthesis.

Spherical silsesquioxane particles are formed by controlled hydrolysis of trialkoxysilane(s) in acidic media, followed by addition of base, storage for at least 2 hours, and spray drying. Essentially non-agglomerated spherical particles are produced without milling.

Spherical silsesquioxane particles are formed by controlled hydrolysis of trialkoxysilane(s) in acidic media, followed by addition of base, storage for at least 2 hours, and spray drying. Essentially non-agglomerated spherical particles are produced without milling.

Described herein is a highly effective route towards the controlled and isotropic reduction in size-scale, of complex 3D structures using silicone network polymer chemistry. In particular, a class of silicone structures were developed that once patterned and cured can shrink micron scale additive manufactured and lithographically patterned structures by as much as 1 order of magnitude while preserving the dimensions and integrity of these parts. This class of silicone materials is compatible with existing additive manufacture and soft lithographic fabrication processes and will allow access to a hitherto unobtainable dimensionality of fabrication.