POLYOLEFIN COMPOSITION AND METHOD FOR ITS PRODUCTION Russian patent published in 1995 - IPC

FIELD: composite materials. SUBSTANCE: proposed composition contains crystalline copolymer of propylene and ethylene and elastomer copolymer of ethylene and C₃-C₄-α olefin being partially soluble in xylene, their quantities are 87.0-92.5 and 7.5-13.0 respectively. Characteristic viscosity of said components fulfils formula 0,23≅ [η]₂/[η]₁×C₂≅ 0,49 where [η]₁ is characteristics viscosity of said crystalline copolymer; [η]₂ is characteristics viscosity of xylene-soluble portion of said copolymer of ethylene and C₃-C₄-α-olefin; C₂ is content of ethylene in said elastomer. Proposed composition is prepared by two-stepped copolymerization. At the first step copolymerization of ethylene and propylene is carried out, the process takes place in the presence of hydrogen; quantity of ethylene and hydrogen being 1.58-2.3 mol and 0.3-0.5 mol respectively. Unreacted monomers are degasified. At the second step copolymerization of ethylene and C₃-C₄-α-olefin is carried out, quantity of ethylene being 25.0-68.5 mol Solid product of interaction of titanium tetrachloride and diisobutyl phthalate (compound having formula MgCl₂·2,1 C₂H₅OH being used as carrier), aluminium-organic cocatalyst and cyclohexyl dimethoxy silane are used as catalytic system. EFFECT: improves quality of desired composition and efficiency of its production. 4 cl, 5 tbl