Method for the production of sodium perborate hydrate granulates

US5395602A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Joerg Herzig · Maintal, DE
• Wolfgang Zikofsky · Ronneburg, DE
• Birgit Bertsch-Frank · Rheinfelden (Baden), DE
• Thomas Lieser · Hanau, DE

Key dates

• Filing date: Dec 18, 1990
• Grant date: Mar 7, 1995
• Expiry date: Dec 18, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B15/12
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention relates to sodium perborate hydrate granulates and a method for producing sodium perborate hydrate granulates with an available oxygen content of 14 to 18% by weight, especially 15 to 16% by weight; an abrasion index according to ISO test 5937 of not more than 10%; with a rate of dissolution of below 1.5 minutes, preferably below 1.0 minutes (for 1 gram of the granulate in 500 cm.sup.3 water, at 15.degree. C.); and with a bulk weight in the range of 0.6 to 1.2 kg/dm.sup.3. The sodium perborate hydrate granulate can be produced by compacting spray-dried, essentially amorphous sodium perborate hydrate starting material which exhibits a bulk weight below that of the granulate product, and a particle size of 90% less than 100 micrometers. The hydrate starting material is further characterized in that it loses 0.2 to 2.0% of its weight when stored at 60.degree. C. and 100 Pa for 30 minutes. The starting material is compacted between rollers at a contact pressure of 5.times.10 to 2.times.10.sup.4 N/cm, and the resultant product is comminuted and the granulate is sieved according to particle size. The compacted granulate particles may be rounded off by means of a mechanical …