Patent ID: 7919561
Filing Date: 2011-04-05
Classification: C08L

Abstract:
1. A process for producing a reactor blend polymer comprising (a) a first polymer component comprising a crystalline propylene polymer having no more than 10% by weight of other monomers and (b) a second polymer component comprising a copolymer of propylene with at least one comonomer, wherein the copolymer comprises between about 7 wt % and about 25 wt % of said at least one comonomer and the copolymer has a heat of fusion of from 0.5 J/g to 70 J/g, a melting point by DSC ranging from 110° C. to 45° C., and an mm triad tacticity of 75% or greater, the process comprising: (i) polymerizing propylene under first polymerization conditions in the presence of a metallocene catalyst in a polymerization reaction zone to produce a first effluent comprising said first polymer component, wherein the first polymerization conditions comprising a first reaction temperature between about 50° C. and about 100° C.; and (ii) subsequently copolymerizing propylene with said at least one comonomer under second polymerization conditions in the presence of said metallocene catalyst and at least part of said first effluent in a second slurry polymerization reaction zone to produce said second polymer component substantially without fouling of said slurry polymerization reaction zone, wherein the second polymerization conditions comprising a slurry process having a second reaction temperature 4° C. or 6° C. less than said first reaction temperature.