Polymer compositions, method of manufacture, and articles formed therefrom
AssigneeSabic Innovative Plastics IP B.V.
InventorsShripathy Vilasagar, Dejin Li, Amit Kulkarni
Life of this patent
Estimating the term…
Abstract
A impact resistant polycarbonate composition comprises an elastomer-modified graft copolymer prepared by an emulsion process in which a composition comprising the elastomer-modified graft copolymer is subjected to treatment with acid to adjust the pH to about 3.0 to about 6.8, following by coagulation of the elastomer-modified graft copolymer and admixture with an aromatic polycarbonate.
Claims38
A polycarbonate composition having improved resistance to polymer degradation comprising, in admixture, an aromatic polycarbonate and an elastomer-modified graft copolymer made by grafting monomers onto an elastomer, wherein the elastomer-modified graft copolymer is prepared by a process comprising emulsion polymerization of the elastomer and grafting of the monomers to obtain a latex comprising the elastomer-modified graft copolymer followed by coagulation of the latex to obtain a coagulated elastomer-modified graft copolymer, wherein prior to coagulation, the pH of the latex is decreased by at least about 0.5 units to obtain a pH of about 3.0 to about 6.8.
An impact resistant polycarbonate polymer composition having improved resistance to polymer degradation comprising about 48 to about 75 weight percent of an aromatic polycarbonate in admixture with about 52 to about 25 weight percent of an elastomer-modified graft copolymer and optional polymeric flow promoter, based on the total weight of aromatic polycarbonate, elastomer-modified graft copolymer, and polymeric flow promoter, wherein the elastomer-modified graft copolymer is prepared by a process comprising:
- emulsion polymerizing a monomer mixture comprising at least butadiene monomer in the presence of a surfactant selected from the group consisting of substituted or unsubstituted alkyl sulfonates, alkylaryl sulfonate, alkyl sulfates, alkylaryl sulfates, alkyl phosphate, alkylaryl phosphates, and mixtures thereof, thereby forming a diene polymer;
- and
- grafting one or more monomers onto the diene polymer, thereby forming a latex composition comprising an elastomer-modified graft copolymer, which latex composition has an alkaline pH;
- and coagulating the latex composition preliminary to admixture with the aromatic polycarbonate;
- wherein, prior to coagulating the latex composition, adjusting the pH of the latex composition comprising the elastomer-modified graft copolymer by introducing an acid, not a buffer, to obtain a pH of about 3.0 to about 6.8, wherein the acid has a pKa of less than 5.0.
A method of preparing an impact modified polycarbonate composition having improved resistance to polymer degradation comprising:
- carrying out emulsion polymerization of a monomer mixture comprising a diene monomer to form a diene polymer;
- grafting monomers onto the diene polymer to form a latex composition comprising an elastomer-modified graft copolymer, which latex composition has an alkaline pH,
- coagulating the latex composition comprising the elastomer-modified graft copolymer product;
- and
- admixing the coagulated elastomer-modified graft copolymer with an aromatic polycarbonate,
- wherein, prior to said coagulation and admixture, adjusting the pH of the latex composition comprising the elastomer-modified graft copolymer by introducing an acid, not a buffer, to obtain a pH of about 3.0 to about 6.8.
Dependencies are inferred from the claim text.