In a polypropylene-based foamed molded body of the present invention, a density which is measured on the basis of ISO1183 is greater than or equal to 0.15 g/cm.sup.3 and less than or equal to 0.54 g/cm.sup.3, thermal resistance (R) at 30° C. in a thickness direction which is measured on the basis of ASTM E1530 is greater than or equal to 0.020 m.sup.2.Math.K/W and less than or equal to 0.125 m.sup.2.Math.K/W, thermal capacity per unit area (Q) at 30° C. is greater than or equal to 1.0 kJ/m.sup.2.Math.K and less than or equal to 2.5 kJ/m.sup.2.Math.K, and Expression 1 described below is satisfied.

Q>1/(4×R.sup.1/2)  (Expression 1)

The present disclosure provides a foam bead. The foam bead contains at least one of the following components: (A) a block composite; and/or (B) a crystalline block composite. The present disclosure also provides a sintered foam structure formed from a composition comprising at least one of the following components: (A) a block composite; and/or (B) a crystalline block composite.

A process for preparing a polyethylene composition comprising contacting ethylene with a first salan catalyst precursor and an activator to form branched vinyl/vinylidene-terminated high density polyethylene having a number average molecular weight (Mn) of at least 5,000 g/mole; and contacting the branched vinyl/vinylidene-terminated high density polyethylene with ethylene and a second metallocene catalyst precursor and an activator to form a comb-block HDPE. The polyethylene composition comprises a polyethylene backbone, and one or more branched high density polyethylene combs pendant to the backbone, the combs having an Mn of at least 5,000 g/mole, where the polyethylene has a branching index (g′) of less than 0.9.

A method for producing a propylene-based block copolymer produces a propylene-based copolymer that exhibits excellent stereoregularity, rigidity, and impact resistance in a convenient and efficient manner while achieving high polymerization activity. The method for producing a propylene-based block copolymer includes bringing a catalyst into contact with propylene, or propylene and an α-olefin, and bringing an electron donor compound into contact with the resulting product to produce a propylene-based block copolymer, the catalyst including a solid catalyst component that includes titanium, magnesium, a halogen, and an internal electron donor compound, a specific organoaluminum compound, and a specific external electron donor compound.

The present invention relates to a solid catalyst for propylene polymerization and a method of producing a propylene polymer or copolymer using the solid catalyst for propylene polymerization, and provides a solid catalyst which prepares a dialkoxymagnesium carrier and is formed of a carrier produced through a reaction of the carrier with a metal halide, a titanium halide, an organic electron donor, etc., and a method of producing a propylene polymer or copolymer through copolymerization of propylene-alpha olefin using the solid catalyst, wherein the dialkoxymagnesium carrier has an uniform particle size range of 10 to 100 μm and a spherical particle shape by adjusting injection amounts, injection numbers, and reaction temperatures of metal magnesium, alcohol and a reaction initiator during a reaction process of metal magnesium and alcohol.

A solid catalyst component for polymerization of olefins is disclosed which can produce a polymer having low stickiness (tackiness) of polymer particles, excellent flowability, and favorable particle size distribution. The solid catalyst component for polymerization of olefins includes titanium, magnesium, a halogen atom and an internal electron donor, wherein the solid catalyst component has a multimodal pore volume distribution measured by a mercury intrusion method and has one or more peak tops in each of a pore radius range from 0.002 μm to 1 μm and a pore radius range from larger than 1 μm to 30 μm or smaller, and a ratio represented by pore volume V1 derived from pores in the radius range from 0.002 μm to 1 μm/pore volume V2 derived from pores in the radius range from larger than 1 μm to 30 μm or smaller is 0.30 to 0.65.

The present invention relates to a polyethylene composition comprising a base resin comprising a low molecular weight ethylene polymer component and a high molecular weight ethylene polymer component, wherein the high molecular weight ethylene polymer component has a higher weight average molecular weight than the low molecular weight ethylene polymer component, wherein the base resin has a density of at least 958.0 kg/m.sup.3, and the polyethylene composition a melt flow rate MFR.sub.2 (190° C., 2.16 kg) of from 0.50 to 0.80 g/10 min and a molecular weight distribution being the ratio of the weight average molecular weight and the number average molecular weight, Mw/Mn, of from 10.0 to 15.0, a process for producing said polyethylene composition, an article comprising said polyethylene composition and the use of said polyethylene composition for the production of a film.

The invention provides a multimodal propylene butene random copolymer having a melt flow rate (MFR2) of 1.0 to 20.0 g/10 min and a butene content of 1.5 to 8.0 wt %, wherein said copolymer is prepared using a single site catalyst and wherein said copolymer comprises (i) 30 to 70 wt % of a propylene butene copolymer (A) having an MFR2 of 0.5 to 20.0 g/10 min and a butene content of 0.5 to 10.0 wt %; and (ii) 70 to 30 wt % of a propylene butene copolymer (B) having an MFR2 of 0.5 to 20.0 g/10 min and a butene content of 1.0 to 8.0 wt %; wherein copolymers (A) and (B) are different.

The invention provides a polyolefin composition comprising: (i) 55 to 95 wt % of a propylene butene random copolymer having an MFR.sub.2 of 1.0 to 20.0 g/10 min, a butene content of 1.5 to 8.0 wt % and prepared using a single site catalyst; and (ii) to 45 wt % of an ethylene based plastomer having a density of 860 to 905 kg/m.sup.3, an MFR.sub.2 of 0.3 to 30 g/10 min and prepared using a single site catalyst.

The invention provides a multimodal propylene butene random copolymer having a melt flow rate (MFR.sub.2) of 1.0 to 20.0 g/10 min and a butene content of 5.0 to 20.0 wt %, wherein said copolymer is prepared using a single site catalyst and wherein said copolymer comprises: (i) 30 to 70 wt % of a propylene butene copolymer (A) having an MFR.sub.2 of 0.5 to 20.0 g/10 min and a butene content of 2.0 to 10.0 wt %; and (ii) 70 to 30 wt % of a propylene butene copolymer (B) having an MFR.sub.2 of 0.5 to 20.0 g/10 min and a butene content of 4.0 to 20.0 wt %; wherein copolymers (A) and (B) are different.