Patent ID: 6031047
Filing Date: 2000-02-29
Classification: B29B,B29K,C08K,C08L,Y10S

Abstract:
A process for the fusion into an intimate blend of a composition comprising(A) 100 parts of a polymer of vinyl chloride;(B) from 0.5 to 10 parts of at least one stabilizer against thermal decomposition of the homopolymer of vinyl chloride:(C) from 1 to 25 parts of a core/shell polymer comprising:(i) from 60 to 90 parts, based on 100 parts of the core/shell polymer, of a core of a copolymer of butyl acrylate of the composition, based on 100 parts of the core, ofa) 60 to 99.9 parts of polymerized units of n-butyl acrylate;b) from 0 to 39.9 parts of polymerized units of an alkyl acrylate other than n-butyl acrylate, the alkyl group containing 2 to 8 carbon atoms;c) from 0.1 to 2.5 parts of polymerized units of at least one non-conjugated polyunsaturated monomer;(ii) correspondingly, from 10 to 40 parts, based on 100 parts of the core/shell polymer, of a shell of copolymer of the composition, based on 100 parts of the shell, ofa) from 50 to 90 parts of polymerized units of methyl methacrylate;b) from 10 to 50 parts of polymerized units of at least one monoethylenically unsaturated alkyl acrylate, the alkyl group containing 2 to 8 carbon atoms;wherein the fusion is characterized by1) a pre-fusion torque value at least 15% higher than that for a control composition equivalent in all respects except that the composition of the shell is at least 95 parts of polymerized units of methyl methacrylate, based on 100 parts of the shell;2) a time to fusion torque no longer than for the control composition;3) maintenance of color at least equivalent to that of the control composition,the process comprising(D) combining the polymer of vinyl chloride, the stabilizer, and the core/shell polymer into a non-compacted blend;(E) heating and admixing with shear the non-compacted blend to convert it to a fused, intimate, cohesive but non-homogenous melt;(F) melt-processing and then cooling the melt to form a useful object in the form of an extruded object, an injection-molded object, a calendered sheet or film, a compression-molded object, an extruded chopped strand, or re-processable pellets.