Patent ID: 6391991
Filing Date: 2002-05-21
Classification: C07C,C08F,Y10S

Abstract:
A process for the preparation of substantially amorphous polymers of propylene having melting enthalpies (&Dgr;Hf) that are not measurable by differential scanning calorimetry, said process comprising polymerizing propylene and optionally one or more olefins to obtain a homopolymer of propylene or a copolymer of propylene with at least 90% by mole of propylene units, said polymerization being carried out in the presence of a catalyst comprising the product of the reaction between:(A) a metallocene compound selected from the group consisting of bis-indenyl compounds of formula (I): â€ƒand the corresponding bis-4,5,6,7-tetrahydroindenyl compounds, wherein: on each indenyl or tetrahydroindenyl group the substituents R1 and R2, same or different from each other, are hydrogen atoms, â€”CHR2 groups, or â€”CHRâ€” groups that form a cycle comprising from 3 to 8 carbon atoms, wherein the R substituents are hydrogen atoms, C1-C20 alkyl radicals, C3-C20 cycloalkyl radicals, C2-C20 alkenyl radicals, C6-C20 aryl radicals, C7-C20 alkaryl radicals or C7-C20 aralkyl radicals and can contain Si or Ge atoms; the substituents R3, R4, R5 and R6, same or different from each other, are defined as R substituents, in addition two adjacent R3, R4, R5 and R6 substituents on the same ring can form a ring comprising from 5 to 8 carbon atoms; M is a transition metal atom of groups IVb, Vb or VIb of the Periodic Table; substituents X, same or different from each other, are hydrogen atoms, halogen atoms, â€”R7, â€”OR7, â€”SR7, â€”NR72 or â€”PR72 groups where substituent R7 are defined as substituent R; and (B) at least a compound selected from the group consisting of (a) organo-metallic compounds of aluminum containing at least a heteroatom selected from the group consisting of oxygen, nitrogen and sulphur, and (b) compounds capable of reacting with the metallocene compound to form an alkyl metallocene cation.