Provided is a method for producing a thermoplastic elastomer composition that can form a molded article having both good appearance and high stiffness. The method for producing a thermoplastic elastomer composition comprises the following first step and second step, wherein the produced thermoplastic elastomer composition contains 5 mass % or less of a mineral oil (C): first step: a step of melt-kneading polypropylene (A-1) and an ethylene-based copolymer rubber (B) in the presence of an organic peroxide, the polypropylene (A-1) being polypropylene of which 20° C. xylene insoluble fraction has an intrinsic viscosity [η.sub.cxis] of 0.1 dl/g or more and less than 1.5 dl/g; and second step: a step of further adding polypropylene (A-2) of which 20° C. xylene insoluble fraction has an intrinsic viscosity [η.sub.cxis] of 1.5 dl/g or more and 7 dl/g or less, and melt-kneading the resulting mixture.

Provided is a thermoplastic elastomer composition obtained by melt-kneading an ethylene/α-olefin/non-conjugated polyene copolymer rubber (A) that is a copolymer of ethylene, an α-olefin having 3 to 20 carbon atoms, and a non-conjugated polyene, a polyolefin resin (B), and a mineral oil-based softening agent (C) in the presence of an organic peroxide (D) and a crosslinking aid (E), the thermoplastic elastomer composition having a shear viscosity of from 5 Pa.Math.s to 20 Pa.Math.s at 140° C. and 10,000 s.sup.−1.

Recycled elements and/or renewable resources, such as recycled carbon black or recycled carbon black and recycled particulate rubber, are incorporated into a rubber composition. The rubber composition can be used to manufacture tires or various tire components including tire subtreads.

A process for the enhancement of the byproducts of a process for the regeneration of exhaust oils is described, wherein said process for the regeneration of exhaust oils which includes at least one of the following steps: a) passing of the oil to be regenerated into one or more centrifuges, b) storage of the oil, before treatment, in suitable containers, c) desiloxanation and d) filtering. The byproducts of one or more of steps a) to d) are treated, gathered and mixed with one another and added to the bitumen coming out as tail of a fractioned distillation step of the above-said regeneration process of exhaust oils.

A plant for the carrying out of a process according to any one of the preceding claims is also described, comprising a processing unit for each of the byproducts coming from steps a) to d) and a mixer (6) with stirring (7).

A filling composition comprises (A) a mineral oil having a kinematic viscosity from 80 cSt to 100 cSt at 40° C.; (B) a styrene-ethylene/propylene diblock copolymer; and (C1) a propylene/ethylene copolymer having a weight average molecular weight (M.sub.w) from 5,000 to 200,000 or (C2) an ethylene/propylene copolymer having a weight average molecular weight (M.sub.w) from 5,000 to 200,000. The filling composition is used as a filling composition in a buffer tube.

Pellet-stable olefinic copolymer bimodal rubber is made using parallel reactors, with one reactor synthesizing higher molecular weight (MW) rubber with dual catalysts, with an improved molecular weight split ratio and an improved composition distribution of the moderate and ultra-high MW components, while another reactor synthesizes random isotactic polypropylene copolymer (RCP). The effluents are reactor-blended and result in pellet-stable bimodal rubber (P-SBR), which may be pelletized. When making thermoplastic vulcanizates (TPVs) with P-SBR, the need to granulate rubber bales and subsequently use talc, clay, or other anti-agglomeration agents to prevent granulated rubber crumbs from agglomerating are eliminated. TPVs made with P-SBR have vulcanized rubber particles that are smaller and more uniform in size, resulting in TPVs with higher particle counts and more thermoplastic “ligaments” between the particles, with such ligaments being made stronger by the added RCP. Such thus-produced TPVs have a lower hysteresis and flexural modulus, and better elastic properties.

A polymer composition including: at least one polymer ingredient selected from the group consisting of a polymer (A) having a side chain (a) containing a hydrogen-bonding cross-linking moiety with a carbonyl-containing group and/or a nitrogen-containing heterocycle and having a glass transition point of 25° C. or lower, and a polymer (B) containing a hydrogen-bonding cross-linking moiety and a covalent-bonding cross-linking moiety in a side chain and having a glass transition point of 25° C. or lower, wherein both the polymer (A) and the polymer (B) are a reaction product of a cross-linking agent with a maleic anhydride graft-modified thermoplastic polymer having a melting point of 64° C. or lower and a maleation rate of 0.1 to 3.0% by mass, and a type A durometer hardness measured under a temperature condition of 20±5° C. according to JIS K6253-3: 2012 is 0 to 49.

The present disclosure provides an oil-extended olefin block copolymer composition. The oil-extended olefin block copolymer composition includes an olefin block copolymer, an oil, and a surface-active agent and may optionally include an olefin-based polymer. The oil-extended olefin block copolymer composition advantageously exhibits reduced, or no, oil-bleed.

The present disclosure relates to a thermoplastic vulcanizate including a polypropylene and a copolymer. The copolymer may have an ethylene content, a propylene content, and an a, α,ω-diene content. The thermoplastic vulcanizate has a shore hardness of about 20 Shore A or greater. Alternatively, a thermoplastic vulcanizate may include a polypropylene and an elastomeric polymer and have a shore hardness of about 50 MPa or greater, a tensile strength at yield of about 18 MPa or greater, and an oil swell of about 15% weight gain or less. Additionally, the present disclosure relates to processes for producing thermoplastic vulcanizates. A process may include introducing a catalyst and propylene to a first reactor to form a first polymer, and introducing the first polymer, ethylene, at least one α,ω-diene, and optionally additional propylene to a second reactor to form an impact copolymer. The process may further include crosslinking the impact copolymer.

Provided is a thermoplastic elastomer composition capable of producing a molded article having a good appearance such as surface smoothness and excellent bondability to another member, the thermoplastic elastomer composition comprising: an ethylene-based polymer (A); and a propylene-based polymer (B), wherein a melt viscosity of the thermoplastic elastomer composition measured at a temperature of 220° C. and a shear rate of 12 sec.sup.−1 is 2,500 Pa.Math.sec or less; the thermoplastic elastomer composition has a sea-island structure; and an island portion has a volume average particle diameter of 2.1 μm or more and a particle diameter dispersion D of 7.0 or less.