Abstract: horny substances are removed from hides of dead animals by a process wherein the hides of dead animals are treated with at least one substance of the formula I or at least one corresponding alkali metal, alkaline earth metal, ammonium or phosphonium salt, where R1 and R4 are identical or different and are selected from hydrogen, C6-C14-aryl and C1-C12-alkyl, unsubstituted or substituted by one or more SH or OH groups, R2 and R3 are identical or different and are selected from hydrogen, C6-C14-aryl and C1-C12-alkyl, unsubstituted or substituted by one or more SH or OH groups, at least one radical R2 or R3 not being hydrogen or R1 and R4 not being hydrogen, and it being possible in each case for two vicinal radicals R1 to R4 together to be C3-C10-alkylene, R5 is selected from hydrogen, C1-C12-alkyl, H—C?O or C1-C4-alkyl-C?O, X1, X2, X3 and X4 are selected from OH, SH and NHR5, where, if R1 to R4 contain at least one sulfur atom, at least one radical X1 to X4 is SH, and, if R1 to R4 contain no sulf

Abstract: A catalyst solid for olefin polymerization comprising

Abstract: In a process for preparing a metal-containing supported catalyst or a metal-containing supported catalyst component by impregnation of a support material with an impregnation solution comprising the metal component, the impregnation solution flows through the support material.

Abstract: The present invention relates to a process for preparing racemic ansa-metallocene complexes I ##STR1## tin compounds II ##STR2## and a process for preparing tin compounds II. R.sup.1 to R.sup.9, M, and X are defined herein.