Abstract: The present invention teaches the use of particular soluble metallocene catalysts to produce stereoregular polymers in gas phase polymerizations wherein the catalysts are fed into a particular lean zone in the reactor. The metallocene catalysts are bridged bis(substituted indenyl) compounds.

Abstract: The present invention relates to compositions containing impact copolymer compositions that are a blend of a propylene polymer phase and a rubber phase in which the ethylene content of the rubber phase is between about 75 to about 95% by weight. The rubber content of the impact copolymer composition ranges between about 35% by weight to about 60% by weight. The crystallinity of the high ethylene-content rubber phase provides overall improvement in film properties and also balance of film tensile properties in the machine and transverse directions. Compared to traditional impact copolymer compositions having a low ethylene content-rubber phase, the inventive copolymers have significantly enhanced melting and crystallization peaks due to polyethylene-like crystallinity in the rubber phase.

Abstract: Novel compositions of the structure ##STR1## wherein R.sup.1 and R.sup.2 are each an alkoxy group which may be the same or different and have from one to ten carbon atoms, and R.sup.3 -R.sup.6 are each individually, hydrogen, hydrocarbyl, hydrocarboxy, nitro, a silyl group or a halogen, with the provisos that if either R.sup.1 or R.sup.2 are methoxy, then at least one of R.sup.3 -R.sup.6 is not hydrogen, if R.sup.1 and R.sup.2 are both ethoxy, then at least one of R.sup.3 -R.sup.6 is not hydrogen, and R.sup.1 and R.sup.2 cannot both be methoxy, are taught herein, which may be used as electron donors, either internal or external, for catalysts used in the polymerization of olefins.

Abstract: The invention teaches a novel design for a fluidized bed polymerization reactor which utilizes a primary fluidization grid to provide mixing and fluidization of the polymer and at least one secondary distribution plate located above the first distribution plate to promote segregation of polymer particles by size, the larger particles falling into the lower fluidization zone and the smaller particles being entrained up from the primary fluidization grid and through the secondary distribution grid into an upper reaction zone.

Abstract: The invention teaches a novel design for a fluidized bed polymerization reactor which utilizes a primary fluidization grid to provide mixing and fluidization of the polymer and at least one secondary distribution plate located above the first distribution plate to promote segregation of polymer particles by size, the larger particles falling into the lower fluidization zone and the smaller particles being entrained up from the primary fluidization grid and through the secondary distribution grid into an upper reaction zone.

Abstract: It has been found that the use of at least one unsupported metallocene polymerization catalyst with at least one supported metallocene polymerization catalyst in the polymerization of olefins allows for better control of the polymerization, especially gas phase polymerization. Such a system takes advantage of the high activity of the unsupported catalyst and the stability of a supported catalyst. Additionally, the relative timing of the addition of the supported and unsupported catalysts to a reaction system can be used to control a continuous polymerization reaction by stabilizing the reactor bed with the supported catalyst prior to addition of the unsupported catalyst.

Abstract: The present invention teaches a process for controlling a continuous gas phase (exothermic) process operating in condensing mode (e.g. polymerization) with a selected temperature for the reactor bed or outlet and with a temperature differential between the reactor inlet and the reactor bed or outlet by controlling the heat transfer provided by the heat exchanger in the recycle line to maintain the selected reactor bed temperature or outlet temperature while simultaneously controlling a condensable liquid feed rate to maintain the temperature differential.

Abstract: A polymer composition having improved balanced mechanical and optical properties comprising (i) a random copolymer comprising from about 0.8% to about 20% by weight of butene-1 and from about 80% to about 99.2% by weight of propylene, and (2) from about 0%-0.35% by weight of polymer composition of a synthetic amorphous silica antiblock agent.

Abstract: A method of deactivating a polyolefin polymer is disclosed whereby the polymer is contacted in a post-reactor vessel with CO.sub.2 and then an acid acceptor and at least one secondary antioxidant are incorporated into the deactivated polyolefin polymer. The resulting product displays improved color and reduced melt flow breaking tendency, and does not exhibit polymer agglomeration and stickiness.

Abstract: The present invention teaches propylene-ethylene copolymers of about 5 to about 100 dg/min melt flow that have a homopolymer phase combined with a copolymer rubber phase in which the ethylene content of the rubber is between about 75 to about 95% w and a clarity of greater than 25%. The rubber content of the copolymer ranges between about 3% w to about 60% w. In addition to improved clarity, these copolymers have high stiffness (flexural modulus) and good falling weight impact toughness at low temperatures.

Abstract: A process for the production of polypropylene comprising continuously contacting liquid propylene or a mixture comprising liquid propylene and one or more other alpha-olefins in one or more reaction zones, under gas phase polymerization conditions, with a catalyst system comprising (i) a solid particulate catalyst precursor, which includes magnesium; titanium; a halogen which is chlorine, bromine, or iodine, or mixtures thereof; and, as an inside electron donor, a carboxylic acid ester; (ii) a hydrocarbylaluminum cocatalyst; and (iii) as an outside electron donor, a silicon compound containing at least one silicon-oxygen-carbon linkage, the particles of precursor being carried into the reaction zone(s) via a portion of the liquid propylene, the flow rate of said portion having a Reynolds number greater than about 15,000.

Abstract: A composition containing a magnesium component, a titanium component, a halide and a 1,2-dialkoxybenzene, wherein at least one alkoxy group has at least two carbon atoms, and the manufacture of the composition are taught by the present invention. The compositions are useful as Ziegler-Natta catalysts in the production of olefin polymers.

Abstract: The present invention teaches the use of an effervescent nozzle to deliver liquid catalyst to a gas phase polymerization system.

Abstract: A method of making a solid, substantially dry olefin polymerization procatalyst precursor is disclosed whereby a solid precursor containing magnesium and titanium is formed in a slurry or solution, the solid then is separated from the solution and then dried at a temperature above 50.degree. C. for over an hour. Solid, substantially dry olefin polymerization procatalyst precursors made by the method also are disclosed, whereby the precursors are easier to handle, have better flowability, reduced clumpness and provide catalysts that can be used to produce polymers having improved extrudability, less filter clogging, less "talc"-like polymer particles of <10 micron in size and reduced polymer product segregation in storage.

Abstract: A process for the separation of a mixture of a titanium tetrahalide, a reaction diluent of an intermediate boiling point and at least one of a titanium alkoxide, ester or complex thereof without the aid of a distinct separation solvent by subjecting the mixture to a first distillation step to separate the titanium tetrahalide as the lights component and subjecting the heavies product to a second distillation step to recover a portion of the reaction diluent as the lights component.

Abstract: For gas phase polymerization reactions in the presence of an unsupported polymerization catalyst, there is provided a process for introducing a liquid catalyst so as to provide a resin particle lean zone such that the average particle size of the resin produced ranges from about 0.01 to about 0.06 inches.

Abstract: Polypropylene impact copolymer compositions are provided which contain a homopolymer phase of predominantly homopolymeric polypropylene, a copolymer phase of copolymerized ethylene and propylene, and a nucleating agent. The inventive compositions have a rubber content (Fc) in the range of 25 to 45% by weight, a crystallization temperature in the range of 122 to 132.degree. C., a melt flow in the range of about 7 to about 60 dg/min, and a ratio of the intrinsic viscosity of the copolymer phase to the intrinsic viscosity of the homopolymer phase of 1.4 to about 1.9. The polypropylene impact copolymer compositions may be used to form cast films which preferably are soft, quiet, and suitable for use in products to be used next to the skin, such as diapers, adult incontinence pads and feminine hygiene products.

Abstract: A process for producing metallocene procatalysts useful in a catalyst system for the polymerization of olefins, particularly to make stereospecific polymers, and more particularly polymerization to make isotactic polypropylene in which the product of a reaction between a suitable ligand and an alkali-alkyl is reacted with a transition metal salt in the presence of an accelerant that has at least one lone pair of electrons in its outer valence shell. When the metallocene procatalyst produced is used in a catalyst system for the production of isotactic polymers, specifically isotactic polypropylene, the metallocene procatalyst can be used without isolating and separating the racemic modification from the meso form.

Abstract: A method for recovering titanium and vanadium compounds, such as alkoxides, from a liquid hydrocarbon mixture by hydrolyzing the mixture with a base or acid wash having a sufficiently different density so that two liquid phases form, and separating the two liquid phases.