Abstract: A method for forming dense ceramics, particularly a ceramic coating by a low temperature treatment is provided. The method for forming ceramics according to the invention is characterized in that a polysilazane having a number-average molecular weight of 100 to 50,000 or a modified polysilazane thereof is subjected to a heat treatment, then exposed to an atmosphere containing water vapor or immersed in distilled water containing a catalyst, or both, or is brought into contact with Pd.sup.2+ ions and water, the polysilazane having a skeleton comprising the unit represented by the following general formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a group other than the above and having a carbon atom directly attached to the silicon atom, an alkylsilyl group, an alkylamino group and an alkoxy group; with the proviso that at least one of R.sup.1, R.sup.2 and R.sup.3 is a hydrogen atom.

Abstract: A method for forming dense ceramics, particularly a ceramic coating by a low temperature treatment is provided. The method for forming ceramics according to the invention is characterized in that a polysilazane having a number-average molecular weight of 100 to 50,000 or a modified polysilazane thereof is subjected to a heat treatment, then exposed to an atmosphere containing water vapor or immersed in distilled water containing a catalyst, or both, or is brought into contact with Pd.sup.2+ ions and water, the polysilazane having a skeleton comprising the unit represented by the following general formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a group other than the above and having a carbon atom directly attached to the silicon atom, an alkylsilyl group, an alkylamino group and an alkoxy group; with the proviso that at least one of R.sub.1, R.sup.2 and R.sup.3 is a hydrogen atom.

Abstract: A process for homopolymerizing an olefin or copolymerizing an olefin with another olefin in the presence of a catalyst composed of(a) a solid catalyst component containing magnesium atoms, titanium atoms, halogen atoms, and an electron donor compound,(b) an organoaluminum compound represented by the formula R.sup.1 R.sup.2 R.sup.3 Al (wherein R.sup.1, R.sup.2, and R.sup.3, which may be the same or different, each denote a C.sub.1-20 alkyl, alkenyl, cycloalkyl, aryl, aralkyl, or alkoxy group, or a hydrogen atom;(c) an organoaluminum compound represented by the formula R.sup.4.sub.3-n AlX.sub.n (wherein R.sup.4 denotes a C.sub.1-20 alkyl, alkenyl, cycloalkyl, aryl, aralkyl, or alkoxy group; X denotes a halogen atom; and n.gtoreq.1),(d) an electron donor compound containing a nitrogen atom, sulfur atom, oxygen atom, or phosphorus atom, and(e) an aromatic ester compound.

Abstract: A catalyst component for polymerization of olefins which is prepared by contacting a product obtained by contacting (A) a magnesium alkoxide, (B) a silicon compound having the hydrogen-silicon bond, and (C) a titanium compound with one another, with (D) (a) a hydrocarbon, (b) a halogenated hydrocarbon, and/or (c) a halide of an element selected from the elements of Groups IIIa, IVa, and Va of the Periodic Table.

Abstract: A cocatalyst employed with a titanium-containing catalyst, said titanium-containing catalyst comprising titanium atoms, halogen atoms, and an electron donor compound, said cocatalyst comprising(a) an organoaluminum compound represented by the formula R.sup.1 R.sup.2 R.sup.3 (wherein R.sup.1, R.sup.2, and R.sup.3 which may be the same or different, each denote a C.sub.1-20 alkyl, alkenyl, cycloalkyl, aryl, aralkyl, or alkoxy group, or a hydrogen atom;(b) an organoaluminum compound represented by the formula R.sub.3-n.sup.4 AlX.sub.n (wherein R.sup.4 denotes a C.sub.1-20 alkyl, alkenyl, cycloalkyl, aryl, aralkyl, or alkoxy group; X denotes a halogen atom; and n.gtoreq.1),(c) an electron donor compound containing a nitrogen atom, sulfur atom, oxygen atom, or phosphorus atom, and(d) an aromatic carboxylic acid ester.The catalyst is useful for the polymerization of olefins.