Naphthenic process oils are made by blending one or more naphthenic vacuum gas oils in one or more viscosity ranges with a high C.sub.A content distilled aromatic extract feedstock to provide at least one blended oil, and hydrotreating the at least one blended oil to provide an enhanced C.sub.A content naphthenic process oil. The order of the vacuum distillation and blending steps may be reversed.

A thermoplastic elastomer composition possessing a good combination of elastic recovery, tear strength at 25° C., stress relaxation and reduced (improved) anisotropy, which is based on a hydrogenated block copolymer (A), a thermoplastic resin (B), a rubber softener (C) and a polyolefin elastomer (D), of specified types and proportions, and which is suitable for use in a variety of film and sheet applications.

A thermoplastic elastomer composition possessing a good combination of elastic recovery, tear strength at 25° C., stress relaxation and reduced (improved) anisotropy, which is based on a hydrogenated block copolymer (A), a thermoplastic resin (B), a rubber softener (C) and a polyolefin elastomer (D), of specified types and proportions, and which is suitable for use in a variety of film and sheet applications.

The invention relates to a process which responds to this problem scenario. The invention therefore relates to a process for preparing a rubber composition based on at least one diene elastomer, a reinforcing filler, a crumb rubber and a crosslinking system, said process comprising at least the following steps: incorporating the reinforcing filler into the diene elastomer, all at once or in several stages, and mixing; when the temperature of the mixture reaches a temperature of greater than 100° C., adding the crumb rubber; continuing the mixing up to a maximum temperature of between 120° C. and 190° C.; cooling the mixture to a temperature of less than 100° C.; incorporating the crosslinking system and mixing up to a maximum temperature of less than 110° C.

The invention relates to a process which responds to this problem scenario. The invention therefore relates to a process for preparing a rubber composition based on at least one diene elastomer, a reinforcing filler, a crumb rubber and a crosslinking system, said process comprising at least the following steps: incorporating the reinforcing filler into the diene elastomer, all at once or in several stages, and mixing; when the temperature of the mixture reaches a temperature of greater than 100° C., adding the crumb rubber; continuing the mixing up to a maximum temperature of between 120° C. and 190° C.; cooling the mixture to a temperature of less than 100° C.; incorporating the crosslinking system and mixing up to a maximum temperature of less than 110° C.

An elastomeric composition is disclosed. The elastomeric composition includes, per 100 parts by weight of rubber (phr): about 5 to about 30 phr of polybutadiene having a cis-1,4 linkage content of at least 95%; about 60 to 100 phr of a styrene/butadiene copolymer; an antioxidant; about 1 to about 20 phr carbon black; about 100-140 phr silica; a silane coupling agent and about 5 to about 40 phr of a polymer selected from the group consisting of ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer. The polymer based on ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer may be functionalized.

An elastomeric composition is disclosed. The elastomeric composition includes, per 100 parts by weight of rubber (phr): about 5 to about 30 phr of polybutadiene having a cis-1,4 linkage content of at least 95%; about 60 to 100 phr of a styrene/butadiene copolymer; an antioxidant; about 1 to about 20 phr carbon black; about 100-140 phr silica; a silane coupling agent and about 5 to about 40 phr of a polymer selected from the group consisting of ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer. The polymer based on ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer may be functionalized.

An elastomeric composition is disclosed. The elastomeric composition includes, per 100 parts by weight of rubber (phr): about 5 to about 30 phr of polybutadiene having a cis-1,4 linkage content of at least 95%; about 60 to 100 phr of a styrene/butadiene copolymer; an antioxidant; about 1 to about 20 phr carbon black; about 100-140 phr silica; a silane coupling agent and about 5 to about 40 phr of a polymer selected from the group consisting of ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer. The polymer based on ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer may be functionalized.

It is an object to provide a tire having well-improved fuel efficiency, wet grip performance, abrasion resistance, and wet grip performance at a later stage of abrasion. Provided is a tire comprising a tread part of a rubber composition comprising a rubber component comprising an isoprene-based rubber and a styrene-butadiene rubber, wherein a vinyl content of the styrene-butadiene rubber is greater than 26 mol %, wherein a given ratio A of an ash content of the rubber composition is greater than 25 mol %, wherein the tread part comprises two or more circumferential main grooves extending in a tire circumferential direction, and land parts partitioned by the circumferential main grooves, wherein at least one land part of the land parts comprises at least one given flask-like circumferential groove extending in the tire circumferential direction.

It is an object to provide a tire having well-improved fuel efficiency, wet grip performance, abrasion resistance, and wet grip performance at a later stage of abrasion. Provided is a tire comprising a tread part of a rubber composition comprising a rubber component comprising an isoprene-based rubber and a styrene-butadiene rubber, wherein a vinyl content of the styrene-butadiene rubber is greater than 26 mol %, wherein a given ratio A of an ash content of the rubber composition is greater than 25 mol %, wherein the tread part comprises two or more circumferential main grooves extending in a tire circumferential direction, and land parts partitioned by the circumferential main grooves, wherein at least one land part of the land parts comprises at least one given flask-like circumferential groove extending in the tire circumferential direction.