Patent · US Expired

Microencapsulated red phosphorus

US6846854B2 · kind B2 · utility

3Cited by

7References

11Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

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

Key dates

Filing date	May 24, 2002
Grant date	Jan 25, 2005
Priority date	—
Expiry date	Jan 7, 2023

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08K9/08
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

A method for preparing encapsulated red phosphorus is disclosed. The method entails obtaining a material system that contains dispersed particulate red phosphorus having a mean particle size of 0.1 to 100 μm in an aqueous phase that comprise urea, formaldehyde and a water-soluble silicon dioxide precursor, adding to the material system a sufficient amount of acid to lower the pH to 0 to 5 and maintaining the resulting acidic system at a temperature of 80 to 120° C. for a period longer than one hour. The encapsulated red phosphorus of the invention is suitable for using as a flame retarding agent for plastics molding compositions.

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