Patent · US Expired

Organosiloxane block copolymers

US4356293A · kind A · utility

9Cited by

3References

5Claims

0Family size

Assignee

Wacker Chemie AG · DE

Inventors

Bernward Deubzer · Burghausen, DE
Norbert Egerter · Emmerting, DE
Volker Frey · Burghausen, DE
Kurt Leitner · Ach, AT

Key dates

Filing date	Nov 28, 1980
Grant date	Oct 26, 1982
Priority date	—
Expiry date	Nov 28, 2000

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08G77/44
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

A process for preparing organosiloxane block copolymers which comprises reacting (a) an organopolysiloxane containing Si-bonded hydroxyl groups and having an average molecular weight of at least 800 g/mole, in which at least 80 mole percent of the units are siloxane units, and one valence of each silicon atom is satisfied by an SiC-bonded organic radical, while the remaining silicon valences are satisfied by siloxane oxygen atoms or hydroxyl groups, with (b) a diorganopolysiloxane having one Si-bonded hydroxyl group in each terminal unit and an average of at least 10 silicon atoms per molecule in the presence of (c) an organic solvent and (d) an alkali metal carbonate and/or an alkali metal carboxylate to form an organosiloxane block copolymer.

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