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.

A process for producing a cap or closure comprising obtaining a polypropylene composition by sequential polymerization comprising the steps: A) polymerizing in a first reactor, preferably a slurry reactor, in the presence of a Ziegler-Natta catalyst monomers comprising propylene and optionally one or more comonomers selected from ethylene and C4-C10 alpha-olefins, to obtain a first propylene polymer fraction having a comonomer content in the range of 0.0 to 1.8 wt %, and a MFR2 in the range of from 12.0 to 40.0 g/10 min, as measured according to ISO 1133 at 230° C. under a load of 2.16 kg; B) polymerizing in a second reactor, preferably a first gas-phase reactor, monomers comprising propylene and one or more comonomers selected from ethylene and C4-C10 alpha-olefins, in the presence of the first propylene polymer fraction, to obtain a second propylene polymer fraction, wherein the polypropylene composition comprising said first and second propylene polymer fractions has an MFR2 in the range of from 12.0 to 60.0 g/10 min, as measured according to ISO 1133 at 230° C. under a load of 2.16 kg, has a comonomer content in the range of from 2.2 to 5.0 wt % and wherein the ratio of the comonomer content of component A) to the comonomer content of the polypropylene composition is 0.35 or less, C) melting, extruding and moulding the polypropylene composition in the presence of at least one nucleating agent to prepare a cap or closure; and D) exposing the cap or closure obtained in step (C) to a cooling rate of 50 K/s or more.

An ethylene-based resin comprising a high molecular weight component and a low molecular weight component, wherein the high molecular weight component comprises an ethylene/alpha-olefin copolymer or ethylene homopolymer, and has a density ranging from 0.940 g/cc to 0.960 g/cc, and a high load melt index (I21.6) ranging from 4 g/10 min to 15 g/10 min, and wherein the ethylene-based resin has: an overall density ranging from greater than 0.955 to less than or equal to 0.970 g/cc, an overall melt index (I2.16) ranging from 0.5 g/10 min to 7 g/10 min, and less than 0.2 vinyls per 1000 carbon atoms.

Compositions may include a polymer melt blend composition prepared from two polyethylene copolymers having different densities, wherein the polymer melt blend composition possesses improved flowability and impact resistance for low thickness rotomolding applications. Low thickness articles may include a polymer melt blend composition prepared from two polyethylene copolymers having different densities, wherein the articles possess improved finishing properties. Rotomolding processes may include melt blending from two polyethylene copolymers having different densities, pulverizing the melt blend, and rotational molding the composition thereof.

The present invention relates to a heterophasic polyolefin composition and articles produced therefrom with improved mechanical and optical properties, particularly low stress whitening. The present invention further relates to a process for the preparation of such a heterophasic polyolefin composition, articles made therefrom, particularly films, and uses of the heterophasic polyolefin composition. The heterophasic propylene copolymer composition comprises a heterophasic propylene copolymer (HECO) comprising a matrix (M) being a propylene homopolymer (H-PP) and an elastomeric propylene copolymer (EPC) dispersed in said matrix (M), wherein the heterophasic propylene copolymer (HECO) has (a) a melt flow rate MFf3/4 (2.16 kg, 230° C.) measured according to ISO 1133 in the range of 5.0 to 25.0 g/10 min, (b) a soluble fraction content (SF) determined by TREF fractionation on CRYSTEX QC, Polymer Char (Valencia, Spain) in the range of 10.0 to 25.0 wt. %, (c) an ethylene content of the soluble fraction content (SF) in the range of from 18 wt. % to less than 39 wt. %, (d) an intrinsic viscosity (IV) determined according to DIN ISO 1628/1 (in decalin at 135° C.) of the soluble fraction (SF) in the range of from 1.5 to 2.5 dl/g, (e) a crystalline fraction content (CF) determined by TREF fractionation on CRYSTEX QC, Polymer Char (Valencia, Spain) in the range of 75 to 90 wt. %, (f) an ethylene content of the crystalline fraction content (CF) of from 0.1 wt. % to 5.0 wt. %, and the heterophasic propylene copolymer composition has a total ethylene content in the range of from 7 to 30 wt. %, determined by quantitative NMR spectroscopy.

New polypropylene composition, which combines low sealing initiation temperature (SIT), high melting temperature, good processability and good optical properties, like low haze, its use of and articles made therefrom.

The present application relates to an olefin polymerization method and system in the field of olefin polymerization. The method combines a supported double catalyst with a series process, introduces a liquid material obtained after heat exchange and gas-liquid separation of a circulation gas flow into a separate first reactor to get into contact with the supported double catalyst for polymerization reaction, and then introduces the reaction material and the first polyolefin generated by reaction into a second reactor to continue polymerization reaction, thereby enabling particles to circulate between first reactor and second reactor, improving mixing effect of two polyolefins with obvious differences in properties, avoiding the occurrence of phase separation, and facilitating the production of polyolefins with excellent performance. At the same time, ethylene gas is introduced into first reactor to further reduce the hydrogen/ethylene ratio, increase the molecular weight of polyethylene and improve the product performance.

Polypropylene polymer compositions are disclosed that have excellent stiffness properties. The polypropylene polymer compositions are made by combining a first polypropylene polymer with a second polypropylene polymer. The combination of polymers has been found to produce a composition having high stiffness properties in addition to excellent toughness properties. In addition, the polymer composition has good flow properties for being molded into various products and articles. Of particular advantage, the different polypropylene polymers can be produced at relatively high catalyst activity, especially in comparison to high crystalline polymers made in the past.

A polypropylene-based resin composition contains: a component (A1) being a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.; and a component (A2) being a polymer selected from the group consisting of (A2-1) a propylene homopolymer, (A2-2) a random copolymer of propylene and an α-olefin having 2 or 4 to 8 carbon atoms, (A2-3) a block copolymer of propylene and an α-olefin having 2 or 4 to 8 carbon atoms, and a combination of the (A2-1), (A2-2), and (A2-3).

The resin composition has a content of the component (A1) of 0.1 to 10 wt % and a content of the component (A2) of 99.9 to 90 wt % based on the total amount of the component (A1) and the component (A2). The component (A2) has a melt flow rate (MFR) (230° C., load: 2.16 kg) of 1 to 500 g/10 min.

A polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution Mw/Mn of <2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000 and a molecular weight distribution Mw/Mn of <2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution Mw/Mn of >2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 10 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of □190 MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of ≤100° C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of ≥160 Newtons.Math.C° (at a film thickness of about 2 mil) and an oxygen transmission rate (OTR) of ≥650 cm3 per 100 inch2 per day (at a film thickness of about 1 mil).