Microcapsules of low-formaldehyde melamine/formaldehyde resins

US6261483A · kind A · utility

Assignee

• BASF SE

Inventors

• Gabriele Frank · Mannheim, DE
• Ralf Biastoch · Speyer, DE
• Matthias Kummer · Schaffhausen, CH

Key dates

• Filing date: Aug 4, 1999
• Grant date: Jul 17, 2001
• Expiry date: Aug 4, 2019

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2985
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Microcapsules are prepared by polycondensation of a melamine/formaldehyde resin mixture in water, in which essentially water-insoluble material forming the capsule core is dispersed, in the presence of an anionic protective colloid, by a process wherein the melamine/formaldehyde resin mixture is composed of: PA1 a) an aqueous solution of a condensate of PA2 a1) 1 mol of melamine, PA2 a2) from 2 to 5 mol of formaldehyde and PA2 a3) from 0 to 0.5 mol of a melamine derivative which can undergo an addition or condensation reaction with formaldehyde and PA2 a4) from 1 to 5 mol of a C.sub.1 -C.sub.3 -alkanol and PA1 b) from 0.01 to 1 mol of a water-soluble primary, secondary or tertiary amine or ammonia.