The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1981
Filed:
Feb. 11, 1980
Wolfgang Dannenberg, Wunstorf, DE;
Walter Heyer, Barsinghausen, DE;
Theo Doldissen, Seelze, DE;
Manfred Zimmermann, Hanover, DE;
Riedel-de Haen Aktiengesellschaft, Hanover, DE;
Abstract
2,2-Bis[4-(2,3-dibromopropoxy)-3,5-dibromophenyl]-propane (BDDP) has the structural formula ##STR1## This bisphenol-A derivative is prepared by reaction of 2,2-bis[4-hydroxy-3,5-dibromophenyl]-propane with an allyl halide and subsequent bromination of the diallyl ether obtained. In the first reaction step, a lower aliphatic alcohol is used as solvent, and in the second reaction step an aromatic halogenated hydrocarbon. The reaction product is then precipitated by excess alcohol, and separated. The BDDP is obtained in the form of granules and is suitable for application as flameproofing agent.