Disclosed herein are ethylene-based polymers generally characterized by a density of at least 0.94 g/cm.sup.3, a high load melt index from 4 to 20 g/10 min, a zero-shear viscosity at 190° C. from 20,000 to 400,000 kPa-sec, and a relaxation time at 190° C. from 225 to 3000 sec. These ethylene polymers can be produced by peroxide-treating a broad molecular weight distribution Ziegler-catalyzed resin, and can be used in large diameter, thick wall pipes and other end-use applications.

The present invention relates to a polyethylene copolymer which has excellent processability and long-term durability, and thus is useful for hollow molding of a pipe or the like.

A flexible conduit used for transportation of hydrocarbon fluids for off-shore and on-shore oil and gas applications includes an inner pressure sheath, at least one reinforcing layer at least partially disposed around the pressure sheath, an outer protective sheath at least partially disposed around the at least one reinforcing layer, and optionally a thermally insulating layer disposed between the at least one reinforcing layer and the outer protective sheath. At least one of the inner pressure sheath, outer protective sheath, and the thermally insulating layer is manufactured using a thermoplastic blend (TPB) composition. The TPB compositions disclosed herein are useful for the formation of at least one polymer layer of the thermoplastic umbilical hoses used for transportation of hydrocarbon fluids.

The present invention relates to a polyethylene composition comprising a base resin having a density of from 950.0 kg/m.sup.3 to 962.0 kg/m.sup.3, determined according to ISO 1183, wherein the polyethylene composition has a melt flow rate MFR.sub.21 (190° C., 21.16 kg), of from 1.0 to 9.0 g/10 min, determined according to ISO 1133 and a viscosity at a constant shear stress of 747 Pa eta.sub.747 of from 3500 kPa #s to 20000 kPa #s, a polyethylene composition obtainable by a multi-stage process, a process for producing said polyethylene composition, an article, such as a pipe or pipe fitting, comprising said polyethylene composition and the use of said polyethylene composition for the production of an article, such as a pipe or pipe fitting.

The present invention relates to a polymeric composition comprising: one or more vinylidene fluoride (VDF) polymers, from 1 to 100 parts, preferably from 2 to 50 parts, more preferably from 2 to 30 parts, even more preferably from 3 to 20 parts by weight for 100 parts of VDF polymer of a plurality of particles of graphite, wherein said particles of graphite have an D90 particle size as measured with laser scattering of less than 50 μm, preferably from 2 to 30 μm more preferably from 2 to 20 μm, even more preferably from 2 to 10 μm and a BET specific surface of from 10 to 50 m.sup.2/g, preferably 15 to 35 m.sup.2/g. The invention also relates to tubular articles comprising the composition and to their use in oil and gas operations.

The present disclosure relates to a polyethylene having high degree of crosslinking and a crosslinked polyethylene pipe including the same. The polyethylene according to the present disclosure has a high content of ultra-high molecular weight, and thus a crosslinking rate is improved, and thus a sufficient degree of crosslinking is exhibited even when the crosslinking time is shortened, thereby exhibiting excellent strength and pressure resistance characteristics.

The present invention relates to a method of coating a pipeline field joint comprising the steps of (a) applying a layer of a coating material composition comprising (i) a propylene polymer and (ii) a substantially linear ethylene copolymer, a linear ethylene copolymer, or mixtures thereof, to the uncoated region of the field joint, preferably the coating is applied by injection molding.

The present invention provides a resin composition for molding that can provide a molded body having excellent heat resistance and excellent mechanical properties as well as high surface smoothness. The present invention also provides a molded body and a pipe each including the resin composition for molding. Provided is a resin composition for molding containing: a chlorinated polyvinyl chloride; a thermal stabilizer; and an impact resistance modifier, the chlorinated polyvinyl chloride having a chlorine content of 63 to 72% by mass, the thermal stabilizer containing a calcium-containing compound and a zinc-containing compound, the resin composition containing the thermal stabilizer in an amount of 0.4 to 10.0 parts by mass and the impact resistance modifier in an amount of 1.0 to 10.0 parts by mass relative to 100 parts by mass of the chlorinated polyvinyl chloride.

The invention relates to a propylene copolymer composition comprising a propylene-ethylene copolymer, wherein the propylene-ethylene copolymer has a melt flow index in the range of 0.05 to 2.5 dg/min measured according to ISO1133 (2.16 kg/230° C.), wherein the propylene-ethylene copolymer is a unimodal propylene-ethylene copolymer and wherein a pipe prepared from the propylene copolymer composition according to ISO 1167-2 has a run time without failure of at least 2,500 h measured according to ISO1167-1 at a temperature of 95° C. and a hoop stress calculated according to ISO3213 of 4.2 MPa.

A process for producing a thermoplastic composite pipe, where the process includes: a) providing a tubular liner having a wall containing a thermoplastic polymer A in the region of the outer surface; b) providing a tape containing reinforcing fibres in a matrix containing a thermoplastic polymer B, where polymer A and polymer B are different; c) applying a film or a composite which is produced in d) and is composed of a film and a tape provided in step b) to the tubular liner, with melting of the outer surface of the liner and of the contact surface of the film either beforehand, simultaneously or thereafter, d) applying the tape provided in b) to the outer surface of the film, with melting of the outer surface of the film applied and of the contact surface of the tape either beforehand, simultaneously or thereafter,
where the surface of the film which is brought into contact with the liner contains a moulding compound containing polymer A to an extent of at least 30% by weight, and the opposite surface of the film contains a moulding compound containing polymer B to an extent of at least 30% by weight.