This disclosure relates to rotomolded articles, having a wall structure, where the wall structure contains at least one layer containing an ethylene interpolymer product, or a blend containing an ethylene interpolymer product and an ethylene polymer, where the ethylene interpolymer product has a Dilution Index (Y.sub.d) greater than 0 and improved Environmental Stress Crack Resistance (ESCR). The ethylene interpolymer product has a melt index from about 0.5 to about 15 dg/minute, a density from about 0.930 to about 0.955 g/cm.sup.3, a polydispersity (M.sub.w/M.sub.n) from about 2 to about 6 and a CDBI.sub.50 from about 50% to about 98%. Further, the ethylene interpolymer products are a blend of at least two ethylene interpolymers; where one ethylene interpolymer is produced with a single-site catalyst formulation and at least one ethylene interpolymer is produced with a heterogeneous catalyst formulation.

Silica-coated alumina activator-supports, and catalyst compositions containing these activator-supports, are disclosed. Methods also are provided for preparing silica-coated alumina activator-supports, for preparing catalyst compositions, and for using the catalyst compositions to polymerize olefins.

The present disclosure relates to dual catalyst systems and processes for use thereof. The present disclosure further provides a catalyst system that is a combination of at least two hafnium metallocene catalyst compounds. The catalyst systems may be used for olefin polymerization processes. The present disclosure further provides for polymers, which can be formed by processes and catalyst systems of the present disclosure.

This invention relates bisindenyl metallocene catalyst compounds having long (at least 4 carbon atoms) linear alkyl groups substituted at the two position and substituted or unsubstituted aryl groups at the four position and process using such catalyst compounds, particularly in the solution process at higher temperatures.

Disclosed are a polyolefin having a high molecular weight by using a novel metallocene catalyst; a method for preparing the polyolefin by using the same; and a method for preparing an ethylene-propylene random copolymer having high molecular weight, high syndiotacticity and small crystal size, thereby providing injection molded articles with improved transparency. The present invention provides a transition metal compound represented by chemical formula 1: ##STR00001##

A lubricating oil composition for compressor oils, including 10 to 99% by mass of a lubricant base oil (A) having a kinematic viscosity at 100° C. of 1 to 14 mm.sup.2/s, a viscosity index of 100 or more, and a pour point of 0° C. or lower, and 90 to 1% by mass of a liquid random copolymer ethylene-α-olefin copolymer (B) of ethylene and α-olefin, the liquid random copolymer ethylene-α-olefin copolymer (B) being prepared by means of a specific catalyst (where the total amount of (A) and (B) is 100% by mass), the lubricating oil composition for compressor oils having a kinematic viscosity at 40° C. of 10 to 300 mm.sup.2/s.

Provided is a polyethylene. More particularly, provided is a polyethylene which has excellent abrasion resistance and thus is suitable for fiber production.

Provided are a novel transition metal compound based on a cyclopenta[a]naphthalene group, a transition metal catalyst composition having high catalytic activity for preparing an ethylene homopolymer or a copolymer of ethylene and at least one α-olefin including the same, a method for preparing an ethylene homopolymer or a copolymer of ethylene and α-olefin using the same, and the ethylene homopolymer or the copolymer of ethylene and α-olefin prepared above. The metallocene compound according to the present invention and the catalyst composition including the same may provide a high thermal stability of the catalyst to maintain high catalytic activity even at a high temperature, have good copolymerization reactivity with other olefins, and prepare a high molecular weight polymer at a high yield.

Provided is a propylene random copolymer having excellent processability. The propylene random copolymer according to the present invention may exhibit high stiffness and flexural modulus together with a low shrinkage ratio, thereby being usefully applied to articles for thin wall injection molding.

A catalyst composition for polymerizing a polyolefin having excellent processability and impact strength, a process for producing a polyolefin and a polyolefin resin thereof are disclosed. The catalyst composition comprises at least one first organometallic compound of following formula 1; at least one second organometallic compound of following formula 2; and aluminoxane. The polyolefin resin satisfies following properties (i) to (iv) and (vi), (i) melt flow index (ASTM D1238), measured at 190° C., under a load of 2.16 kg: 0.1 to 1.5 g/10 min, (ii) density: 910 to 930 kg/m.sup.3, (iii) the ratio (Mw/Mn), as measured by gel permeation chromatography (GPC): 3.0 to 7.0, (iv) the ratio (Mz/Mw), as measured by GPC: 2.2 to 4.5, and (vi) when the TREF curve of multimodal distribution is deconvoluted, the area of TREF curve having a peak at 50 to 74° C. is 40 to 75% of the total area of the TREF curve.