Toa Nenryo Kogyo Kabushiki Kaisha

Tonen Corporation

Masahiro Kokubo

Yasuo Shimizu

Tadashi Suzuki

Hiroyuki Aoki

Nobuaki Tagaya

Satoshi Sakurada

Takao Hashimoto

Tsugio Maeshima

Takaaki Sakurai

Masami Kizaki

Yuji Tashiro

Hideki Matsuo

Kayako Ueda

Haruo Hashimoto

Takashi Ohbayashi

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. A method wherein said modified polysilazane is only fired at a temperature of 400.degree. C. or below is also provided.

Method and composition for forming ceramics and article coated with the

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. A method wherein said modified polysilazane is only fired at a temperature of 400.degree. C. or below is also provided.

1-Butene and isobutene are effectively separated without isomerization of 1-butene by contacting an isobutene-containing hydrocarbon mixture with a solid acid catalyst having a solid acid quantity of 0.05 to 0.25 mmol/g of solid acid catalyst, represented by the adsorption quantity of pyridine, thus low-polymerizing selectively isobutene and then separating the low polymers of isobutene from 1-butene.

Process for the low polymerization of isobutene

1-Butane and isobutene are effectively separated without isomerization of 1-butene by contacting an isobutene-containing hydrocarbon mixture with a solid acid catalyst having a solid acid quantity of 0.05 to 0.25 mmol/g of solid acid catalyst, represented by the adsorption quantity of pyridine, thus low-polymerizing selectively isobutene and then separating the low polymers of isobutene from 1-butene.

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Saitama, Japan

Masahiro Kokubo