New, improved silica supported catalyst system, which comprises a specific class of metallocene complexes in combination with a boron containing cocatalyst and an aluminoxane cocatalyst, its use for producing propylene homopolymers, propylene copolymers, especially with ethylene, as well as heterophasic propylene copolymers, preferably in a multistep process including a gas phase polymerization step.

The present invention relates to an amorphous polyolefinic ionomer and a process for the preparation of an amorphous polyolefinic ionomer.

An object of the present disclosure is to provide a method for manufacturing a copolymer, wherein a crystal content and a vinyl bond content (or a glass transition temperature) of the copolymer can be controlled. Specifically, the present disclosure provides a method for manufacturing a copolymer, wherein the method comprises a process of copolymerizing ethylene with isoprene under the presence of a polymerization catalyst composition containing a half metallocene cation complex represented by following general formula (I)

##STR00001##

(In formula (I), M represents a lanthanoid element, scandium or yttrium; Cp.sup.R′ represents substituted cyclopentadienyl, substituted indenyl or substituted fluorenyl; X represents hydrogen atom, halogen atom, alkoxy, thiolate, amide, silyl, or a C.sub.1-20 monovalent hydrocarbon group; L represents a neutral Lewis base; w represents an integer in the range of 0 to 3; and [B].sup.− represents a non-coordinating anion), wherein Cp.sup.R′ in general formula (I) has at least two substituent groups.

A Ziegler-Natta catalyst composition is disclosed. The catalyst composition is formed from a procatalyst containing a magnesium moiety and a titanium moiety. At least one internal electron donor is incorporated into the procatalyst. During a titanation procedure in conjunction with the internal electron donor, a titanium extractant is used to remove or deactivate low activity or atactic titanium active sites.

This invention relates to polymers comprising: one or more that include 1) at least 11 wt % 4 substituted 1,4 hexadiene and less than 20 wt % 5-methyl-1,4-hexadiene, based upon the weight of the polymer, and 2) optionally, one or more olefins; and processes to produces such polymers using metallocene or post-metallocene catalyst compounds.

The present disclosure relates to a crosslinked polyethylene pipe having excellent physical properties. The crosslinked polyethylene pipe according to the present disclosure has optimized the degree of crosslinking and storage modulus by finding out the optimum physical property range between the degree of crosslinking and the storage modulus which have a mutual trade-off relationship, whereby the crosslinked polyethylene pipe according to the present disclosure has excellent long-term durability and short-term pressure resistance, and thus can be applied to various fields requiring these physical properties.

Fluorided silica-coated alumina activator-supports have a bulk density from 0.15 to g/mL, a total pore volume from 0.85 to 2 mL/g, a BET surface area from 200 to 500 m.sup.2/g, an average pore diameter from 10 to 25 nm, and from 80 to 99% of pore volume in pores with diameters of greater than 6 nm. Methods of making the fluorided silica-coated alumina activator-supports and using the fluorided silica-coated aluminas in catalyst compositions and olefin polymerization processes also are described. Representative ethylene-based polymers produced using the compositions and processes have a melt index of 0.1 to 10 g/10 min and a density of 0.91 to 0.96 g/cm.sup.3, and contain from 70 to 270 ppm solid oxide and from 2 to 18 ppm fluorine.

Provided are a hybrid supported catalyst which includes two or more kinds of transition metal compounds having the following Chemical Formulas 1 and 2, thereby preparing a polyolefin, particularly, a high-density polyethylene having a molecular structure which is optimized to improve tensile strength of a chlorinated polyolefin compound, and a method of preparing a polyolefin using the same:

##STR00001## wherein all the variables are described herein.

Catalyst systems and methods for making and using the same. A method of methylating a catalyst composition while substantially normalizing the entiomeric distribution is provided. The method includes slurrying the organometallic compound in dimethoxyethane (DME), and adding a solution of RMgBr in DME, wherein R is a methyl group or a benzyl group, and wherein the RMgBr is greater than about 2.3 equivalents relative to the organometallic compound. After the addition of the RMgBr, the slurry is mixed for at least about four hours. An alkylated organometallic is isolated, wherein the methylated species has a meso/rac ratio that is between about 0.9 and about 1.2.

The present invention relates to a semi-crystalline polyolefinic ionomer and a process for the preparation of a semi-crystalline polyolefinic ionomer.