Abstract:
A method for producing propylene polymers having a broad molecular weight distribution (MWD) is disclosed. The method uses a Ziegler catalyst and one silane donor. The silane donor is selected from vinyltrimethoxysilane or dicyclohexyldimethoxysilane. The polymers made by the method have an MWD greater than or equal to 7.0.
Abstract:
An ethylene polymerization catalyst and catalyst system which provides an ethylene copolymer which is characterized by desirable ER shift values. The high level ER shift of these polymers produce films having high impact strength. The catalyst is prepared by treating a support material with an agent selected from the group consisting of a compound having the structural formula BX53, where X5 is fluorine, chlorine, bromine, iodine or OR5, where R5 is C1-C6 alkyl; a compound having the structural formula X62 where X6 is fluorine, bromine or iodine; a compound having the structural formula NR6, where R6 is C1-C6 alkyl or OR7, where R7 is C1-C8 alkyl; and a compound having the structural formula Ti(OR8)4, where R8 is C1-C6 alkyl or phenyl to reduced surface hydroxyl group concentration of the support material. The thus treated support material is thereupon contacted with a dialkylmagnesium compound or complex, an alcohol compound or a silane compound and a transition metal compound, in that order. Alternatively, the sequence of contact of the transition metal compound and the silane compound may be reversed, as may be the sequence of addition of the dialkylmagnesium compound or complex and the silane compound.