Method for making polysilazanes

US4675424A · kind A · utility

Assignee

• UNION CARBIDE CORPORATION · US

Inventors

• Roswell E. King, III · Pleasantville, US
• Bernard Kanner · West Nyack, US
• Steven P. Hopper · Glen Ellyn, US
• Curtis L. Schilling, Jr. · Croton-on-Hudson, US

Key dates

• Filing date: Mar 19, 1986
• Grant date: Jun 23, 1987
• Expiry date: Mar 19, 2006

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F7/10
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A method of preparing silazane polymers, with 3 or more repeating units, of the general formula EQU --((CH.sub.3).sub.2 N).sub.e Si(R).sub.a (R'HN).sub.f H.sub.c (NR').sub.g -- and a (CH.sub.3).sub.2 NH byproduct group where R is hydrogen, an alkyl group having 1-6 carbon atoms or an aryl group having 6-12 carbon atoms, a=0, or 1, b=2-4, C=0-2, d=0 or 1, e=0-2, f=0-2, g=1-3 and a+c+e+f+g=4 for the polymer units; and R' is hydrogen or methyl, whereby the silazane polymer is substantially free of halide impurities, and wherein this method comprises: PA0 transaminating an aminosilane of the general formula (R).sub.a ((CH.sub.3).sub.2 N).sub.b H.sub.c S; where R is defined as above and a+b+c=4 with an amine of the general formula (CH.sub.3).sub.d NH.sub.3-d whereby d is defined as above and the amine has a molecular weight lower than 45 all in the presence of an acid catalyst or the ammonium salt of the acid and thereafter condensing to form the polymer.