Propylene polymerization method
AssigneeQuantum Chemical Corporation
InventorsCharles K. Buehler, Cindy S. Senger, Kenneth W. Johnson
Life of this patent
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Abstract
A catalyst component useful in propylene polymerization in combination with a dialkyl aluminum halide cocatalyst comprises the product of reaction of TiCl.sub.3 which is substantially free of extraneous halide with a selected electron donor compound which is dissolved in a liquid hydrocarbon solvent in which the TiCl.sub.3 is dispersed. The electron donor compound is selected from certain organic acid esters, hindered phenolic compounds and silyl esters. The catalyst of the invention provides increased activity, molecular weight control, increased isotacticity of propylene polymer products and prevents catalyst feed line pluggage, among other advantages.
Claims40
A method of homopolymerizing propylene or copolymerizing propylene with at least one other polymerizable 1-olefin having two to eight carbon atoms, inclusive, said method comprising the step of polymerizing said propylene and said 1-olefin, if any, under polymerizing conditions in the presence of a catalyst system comprising a dialkyl aluminum halide cocatalyst in combination with a catalyst component being prepared by reacting TiCl3 which is substantially free of extraneous halide with an electron donor compound dissolved in a liquid hydrocarbon solvent in which said TiCl3 is dispersed, said electron donor compound being selected from the group consisting of:
- (a) organic acid esters of the general formula ##STR3## wherein R.sup.1 is an alkyl group of 1 to 16 carbon atoms, inclusive;
- (b) hindered phenolic compounds of the general formula ##STR4## wherein R.sup.2 is an alkyl group of 1 to 6 carbon atoms, inclusive;
- R.sup.3 is hydrogen or an alkyl group of 1 to 6 carbon atoms, inclusive;
- and R.sup.4 is an alkyl group of 2 to 24 carbon atoms, inclusive;
- and
- (c) silyl esters of the general formula
- R.sup.5.sub.n Si(OR.sup.6).sub.4-n
- wherein R.sup.5 and R.sup.6 can be the same or different and are alkyl groups of 1 to 8 carbon atoms, inclusive, or aryl groups, and n=1 or 2.
A method of homopolymerizing propylene or copolymerizing propylene with at least one other polymerizable 1-olefin having two to either carbon atoms, inclusive, said method comprising the step of polymerizing said propylene and said 1-olefin, if any, under polymerizing conditions in the presence of a catalyst system comprising a dialkyl aluminum halide cocatalyst in combination with a catalyst component, said catalyst component being substantially free of extraneous halide and prepared by a method consisting essentially of the step of reacting reactants consisting essentially of unmilled TiCl.sub.3 which is substantially free of extraneous halide and an electron donor compound dissolved in a liquid alkane or cycloalkane solvent containing substantially no olefin in which said TiCl.sub.3 is dispersed without a milling step whereby said TiCl.sub.3 is modified, said electron donor compound being selected from the group consisting of:
- (a) organic acid esters of the general formula ##STR5## wherein R.sup.1 is an alkyl group of 1 to 16 carbon atoms, inclusive;
- (b) hindered phenolic compounds of the general ##STR6## wherein R.sup.2 is an alkyl group of 1 to 6 carbon atoms, inclusive;
- R.sup.3 is hydrogen or an alkyl group of 1 to 6 carbon atoms, inclusive;
- and R.sup.4 is an alkyl group of 2 to 24 carbon atoms, inclusive;
- and
- (c) silyl esters of the general formula
- R.sub.n.sup.5 Si(OR.sup.6).sub.4-n
- wherein R.sup.5 and R.sup.6 can be the same or different and are alkyl groups of 1 to 8 carbon atoms, inclusive, or aryl groups, and n=1 or 2.
A method of homopolymerizing propylene or copolymerizing propylene with at least one other polymerizable 1-olefin having two to either carbon atoms, inclusive, said method comprising the step of polymerizing said propylene and said 1-olefin, if any, under polymerizing conditions in the presence of a catalyst system comprising a dialkyl aluminum halide cocatalyst in combination with a catalyst component, which is substantially free of extraneous halide and prepared by reacting TiCl.sub.3 which is substantially free of extraneous halide with an electron donor compound dissolved in a liquid hydrocarbon solvent in which said TiCl.sub.3 is dispersed, said electron donor compound being selected from the group consisting of:
- (a) organic acid esters of the general formula ##STR7## wherein R.sup.1 is an alkyl group of 1 to 16 carbon atoms, inclusive;
- (b) hindered phenolic compounds of the general formula ##STR8## wherein R.sup.2 is an alkyl group of 1 to 6 carbon atoms, inclusive;
- R.sup.3 is hydrogen or an alkyl group of 1 to 6 carbon atoms, inclusive;
- and R.sup.4 is an alkyl group of 2 to 24 carbon atoms, inclusive;
- and
- (c) silyl esters of the general formula
- R.sub.n.sup.5 Si(OR.sup.6).sub.4-n
- wherein R.sup.5 and R.sup.6 can be the same or different and are alkyl groups of 1 to 8 carbon atoms, inclusive, or aryl groups, and n=1 or 2.
Dependencies are inferred from the claim text.