Process for preparation of 2-chloro-1,3-butadiene graft copolymers
AssigneeE. I. Du Pont de Nemours and Company
InventorFurman E. Glenn, Sr.
Life of this patent
Estimating the term…
Abstract
Graft copolymers of chloroprene and alkyl or cycloalkyl esters of unsaturated acids are prepared in a one-stage programmed temperature process.
Claims11
A process for preparation of an addition polymer consisting essentially of copolymerized backbone units of 2-chloro-1,3-butadiene and at least one ester monomer of the formula ##STR5## wherein R' is H or an unbranched alkyl radical having 1-4 carbon atoms, and R is an alkyl, hydroxyalkyl, or cycloalkyl radical having 1-12 carbon atoms, with additional units of said ester monomer or monomers grafted onto the copolymer backbone, said process consisting essentially of
- a) preparing an aqueous emulsion of a mixture
- consisting essentially of said ester monomer or monomers and 2-chloro-1,3-butadiene, in a weight ratio of 5-100 parts total ester monomer per 100 parts 2-chloro-1,3-butadiene, in an inert atmosphere, in the presence of a free radical generator and an anionic surfactant, and at a temperature no greater than 25.degree. C.;
- b) allowing polymerization of said ester monomer or monomers and 2-chloro-1,3-butadiene to proceed at a temperature no greater than 25.degree. C. until 35-90 weight percent of said total ester monomer has copolymerized;
- c) raising the temperature of the emulsion to at least 35.degree. C.;
- and
- d) continuing the polymerization at a temperature of at least 35.degree. C., until at least 90% of said total ester monomer has reacted;
- provided that no substantial quantity of any additional monomer is added to the aqueous emulsion after initiation of polymerization.
A process for preparation of an addition polymer consisting of copolymerized backbone units of 2-chloro-1,3-butadiene and at least one ester monomer of the formula ##STR6## wherein R' is H or an unbranched alkyl radical having 1-4 carbon atoms, and R is an alkyl, hydroxyalkyl, or cycloalkyl radical having 1-12 carbon atoms, with additional units of said ester monomer or monomers grafted onto the copolymer backbone, said process consisting essentially of
- a) preparing an aqueous emulsion of a mixture consisting of said ester monomer or monomers and 2-chloro-1,3-butadiene, in a weight ratio of 5-100 parts total ester monomer per 100 parts 2-chloro-1,3-butadiene, in an inert atmosphere, in the presence of a free radical generator and an anionic surfactant, and at a temperature no greater than 25.degree. C.;
- b) allowing polymerization of said ester monomer or monomers and 2-chloro-1,3-butadiene to proceed at a temperature no greater than 25.degree. C. until 35-90 weight percent of said total ester monomer has copolymerized;
- c) raising the temperature of the emulsion to at least 35.degree. C.;
- and
- d) continuing the polymerization at a temperature of at least 35.degree. C. until at least 90% of said total ester monomer has reacted;
- provided that no substantial quantity of any additional monomer is added to the aqueous emulsion after initiation of polymerization.
Dependencies are inferred from the claim text.