摘要:
A method of preparing ultra high melt flow polypropylene having reduced xylene solubles is provided. The method utilizes a diether internal donor-containing Ziegler-Natta catalyst system to polymerize propylene. The polypropylene produced is characterized by having a melt flow of at least about 300 g/10 min and a xylene solubles of not more than about 3.5% and no peroxide residue. The catalyst system may also include an internal phthalate donor. The method of the invention allows the amount of external donors to be reduced, or even eliminated, without significant increases in xylene solubles.
摘要:
Provided is process of polymerizing monomer having at least one Ziegler-Natta polymerizable bond, comprising contacting monomer with, reacting monomer in presence of, or combinations thereof, catalyst system comprising:
A) catalyst component consisting essentially of
i) about 1.5 weight % to about 6 weight % titanium, ii) about 10 weight % to about 20 weight % magnesium, iii) about 40 weight % to about 70 weight % halogen, iv) about 5 weight % to about 25 weight % polycarboxylic ester selected from the group consisting of esters aliphatic, aromatic, alicyclic polycarboxylic acids, or combinations thereof or alkyl phthalates, and v) about 0.1 weight percent to about 2.5 weight % organic phosphorous compound selected from the group consisting of hydrocarbon esters of phosphoric acid such that each hydrocarbon group has one to about six carbon atoms;
B) electron donor described by the formula: wherein R 1 is alkyl or cycloakylgroup containing at least one secondary or tertiary carbon atom, R 2 and R 3 are each independently alkyl or aryl group, and R 4 is an alkyl group having a primary carbon bonded to the silicon atom; and C) organic aluminum compound.