Preparation of ABS molding materials

US5387650A · kind A · utility

Assignee

• BASF SE

Inventors

• Ehrenfried Baumgartner · Bad Dürkheim, DE
• Juergen Hofmann · Salzwedel, DE
• Rudolf H. Jung · Worms, DE
• Rainer Moors · Schifferstadt, DE
• Hansjoerg Schaech · Ludwigshafen, DE

Key dates

• Filing date: Jan 11, 1994
• Grant date: Feb 7, 1995
• Expiry date: Jan 11, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F279/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the continuous preparation of high-impact polystyrene-acrylonitrile (ABS) by free radical-initiated polymerization of a mixture of from 60 to 90% by weight of at least one vinylaromatic monomer and from 10 to 40% by weight of least one further ethylenically unsaturated monomer, in the presence of from 5 to 30% by weight, based on the sum of the monomers, of polybutadiene having a solution viscosity (5% strength by weight in styrene at 25.degree. C.) from 25 to 95 mPa.s and in the presence or absence of a solvent, in at least three consecutive reactors operated essentially without back-mixing, at from 50.degree. to 170.degree. C., phase inversion taking place in one of the reactors, involves carrying out the polymerization as far as phase inversion at 90.degree. C. or below and initiating the polymerization by free radicals from the decomposition of tert-butyl peresters whose half life period at 90.degree. C. is not more than 20 minutes, the polybutadiene content, based on the total reaction mixture, being at least 10% by weight and at most 25% of the total amount of chain-transfer agent (regulator) required being added up to the time of phase inversion and the remaind…