Patent · US Expired

Microencapsulation of red phosphorus

US6765047B2 · kind B2 · utility

0Cited by

6References

15Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Henricus Peerlings · Solingen, DE
Michael Wagner · Dortmund, DE
Wolfgang Podszun · Neunburg vorm Wald, DE

Key dates

Filing date	May 24, 2002
Grant date	Jul 20, 2004
Priority date	—
Expiry date	Jan 21, 2023

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC09K21/04
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

A method for microencapsulating red phosphorus in polymerized urea resorcinol formaldehyde resin is disclosed. The method entails (i) preparing an aqueous mixture containing urea, resorcinol and formaldehyde, (ii) adding hexamethylene tetramine and optionally water to the mixture to yield a stabilized mixture (iii) dispersing red phosphorus in the to the stabilized mixture (iv) adding acid to the reaction mixture, and (v) collecting the resulting encapsulated red phosphorus. The product is suitable as flame retarding agent in molding compositions.

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