Patent · US Expired

Production of diorganopolysiloxanes having silanol end groups

US4960850A · kind A · utility

2Cited by
7References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 18, 1988
Grant dateOct 2, 1990
Priority date—
Expiry dateApr 18, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08G77/32
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

Polydiorganosiloxanes having silanol end groups, well suited for the production of vulcanizable silicone compositions, are conveniently prepared by bulk polycondensing a polydiorganosiloxane oligomer having silanol end groups in a closed reaction zone in the presence of a catalytically effective amount of trifluoromethylsulfonic acid, at a temperature of from 20.degree. to 160.degree. C., while continuously removing water of polycondensation, and terminating the polycondensation reaction by adding a catalyst neutralizing amount of a cyclopolydiorganosilazane or a polydiorganosilazane having diorganoaminosilyl end groups to the medium of reaction.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.