Patent ID: 8822572
Filing Date: 2014-09-02
Classification: B01J,C08F,C09D

Abstract:
1. A process for the aqueous, radically initiated, continuous emulsion polymerization of A) at least one vinyl ester and optionally at least one (meth)acrylic ester, B) ethylene, and C) 0% to 10% by weight, based on the total weight of the monomers, of one or more ethylenically unsaturated, functionalized comonomers, in the presence of 3.0% to 12.5% by weight, based on the total weight of the monomers, of a mixture of one or more nonionic emulsifiers and one or more anionic emulsifiers, where at least 50% by weight, based on the total weight of emulsifiers, are nonionic emulsifiers, and 0% to 10% by weight, based on the total weight of the monomers, of one or more protective colloids, in a stirred-tank cascade with at least two serial pressure reactors and downstream therefrom at least one low-pressure reactor, where polymerization takes place in the pressure reactors at a temperature of 50° C. to 90° C. under a pressure of 10 to 90 bar abs., and the polymerization is conducted such that at least 80% by weight of the total weight of emulsifiers is metered in the first pressure reactor, and at least 50% by weight each of the total weight of comonomer A) and comonomer B) is added in the first pressure reactor, the remaining amounts of the monomers A) and B) are added in the following pressure reactors, and the polymerization in the first pressure reactor is conducted through to a monomer conversion of ≧30% by weight, based on the total amount of the monomers used in the process, and in the last pressure reactor it is conducted through to a monomer conversion of ≧90% by weight, based on the total weight of the monomers used in the process, and polymerization to completion takes place in the at least one low-pressure reactor at a temperature of 30° C. to 60° C. under a pressure of not more than 4 bar abs.