Defoaming agent for plastic dispersions and disperse coating materials and its preparation

US4562223A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Helmut Steinberger · Leverkusen, DE
• Werner Clarenz · Leverkusen, DE

Key dates

• Filing date: Aug 4, 1983
• Grant date: Dec 31, 1985
• Expiry date: Aug 4, 2003

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D19/0409
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A dispersion comprising a solvent having dispersed therein a plastic and a defoaming agent comprising by weight approximately (a) 80 to 100% by weight of a polyoxyalkylenesiloxane copolymer of the formula EQU [R.sup.1 Si(OSiR.sub.2).sub.n ].sub.m Z.sub.m-1 (OR.sup.2).sub.m+2 in which PA0 R represents an optionally halogen-substituted alkyl group with up to 4 C atoms, PA0 R.sup.1 represents the substituent R or a phenyl radical, PA0 R.sup.2 represents a group of the composition ##STR1## Z represents the difunctional unit --O-- or ##STR2## and R.sup.3 denotes a hydrocarbon radical with up to 6 C atoms, PA0 R.sup.4 denotes independently of one another hydrogen or R.sup.3, PA0 n denotes a number between 3 and 40, PA0 m denotes a number between 1 and 15, PA0 x denotes a number between 0 and 68, PA0 y denotes a number between 0 and 52, PA0 x+y denotes a number between 1 and 68 and (b) 0-20% by weight of a hydrophobic silicon dioxide, whereby substantially bubble-free films can readily be prepared therefrom.