Method of making coated granular bleach activators by spray drying

US4457858A · kind A · utility

Assignee

• Henkel Kommanditgesellschaft auf Aktien · DE

Inventors

• Herbert Saran, deceased · Hilden, DE
• Martin Witthaus · Goldkronach, DE

Key dates

• Filing date: Jul 7, 1982
• Grant date: Jul 3, 1984
• Expiry date: Jul 7, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C11D17/0039
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Coated granular bleach activators and a process for their preparation comprising spray drying an aqueous slurry containing 1 to 1.7 parts by weight of water per part of a mixtue of (A) a powdery bleach activator and (B) at least one water soluble cellulose ether, starch, or starch ether in a ratio of A:B of from 99:1 to 90:10. The process utilizes a current of a drying gas having an entrance temperature of 100.degree.-200.degree. C. and an exit temperature of 40.degree.-120.degree. C.