A method for manufacturing a chloroprene polymer composition, the method including: a polymerization step of polymerizing chloroprene in the presence of at least one rosin acid component selected from the group consisting of a rosin acid and a rosin acid salt to obtain a chloroprene polymer composition containing a chloroprene polymer, in which in the rosin acid component, a mass ratio B1/A1 of a total amount B1 of abietic acid, neoabietic acid, palustric acid, levopimaric acid, and salts thereof with respect to a total amount A1 of dehydroabietic acid, pimaric acid, isopimaric acid, dihydroabietic acid, and salts thereof is 0.10 to 3.00, and a toluene insoluble content of the chloroprene polymer is 50% by mass or more.

A method for manufacturing a chloroprene polymer composition, the method including: a polymerization step of polymerizing chloroprene in the presence of at least one rosin acid component selected from the group consisting of a rosin acid and a rosin acid salt to obtain a chloroprene polymer composition containing a chloroprene polymer, in which in the rosin acid component, a mass ratio B1/A1 of a total amount B1 of abietic acid, neoabietic acid, palustric acid, levopimaric acid, and salts thereof with respect to a total amount A1 of dehydroabietic acid, pimaric acid, isopimaric acid, dihydroabietic acid, and salts thereof is 0.10 to 3.00, and a toluene insoluble content of the chloroprene polymer is 50% by mass or more.

Essentially ETU-free cross linkable compositions comprising chloroprene rubber, a cross-linker and a vulcanization accelerator, which have a defined content of ions from the second or third main group and resinate anions and thus possesses improved curing characteristics, a process for vulcanization of such compositions and vulcanizates obtained thereby.

Essentially ETU-free cross linkable compositions comprising chloroprene rubber, a cross-linker and a vulcanization accelerator, which have a defined content of ions from the second or third main group and resinate anions and thus possesses improved curing characteristics, a process for vulcanization of such compositions and vulcanizates obtained thereby.

The present invention relates to [1] a plasticizer for a halogen-based resin containing a mixture of didecyl phthalates each containing a linear or branched C.sub.10 alkyl group, in which a content of di-n-decyl phthalate in the mixture is not less than 48 mol % and not more than 70 mol %; [2] a plasticizer composition for a halogen-based resin containing the aforementioned plasticizer; and [3] a halogen-based resin composition containing a halogen-based resin and the aforementioned plasticizer. The plasticizer of the present invention has an excellent plasticizing effect on a halogen-based resin and at the same time, can exhibit excellent effects of improving all of productivity, processability, kneading properties and heat resistance without deterioration in the respective properties.

The present invention relates to [1] a plasticizer for a halogen-based resin containing a mixture of didecyl phthalates each containing a linear or branched C.sub.10 alkyl group, in which a content of di-n-decyl phthalate in the mixture is not less than 48 mol % and not more than 70 mol %; [2] a plasticizer composition for a halogen-based resin containing the aforementioned plasticizer; and [3] a halogen-based resin composition containing a halogen-based resin and the aforementioned plasticizer. The plasticizer of the present invention has an excellent plasticizing effect on a halogen-based resin and at the same time, can exhibit excellent effects of improving all of productivity, processability, kneading properties and heat resistance without deterioration in the respective properties.

The present invention relates to [1] a plasticizer for a halogen-based resin containing a mixture of didecyl phthalates each containing a linear or branched C.sub.10 alkyl group, in which a content of di-n-decyl phthalate in the mixture is not less than 48 mol % and not more than 70 mol %; [2] a plasticizer composition for a halogen-based resin containing the aforementioned plasticizer; and [3] a halogen-based resin composition containing a halogen-based resin and the aforementioned plasticizer. The plasticizer of the present invention has an excellent plasticizing effect on a halogen-based resin and at the same time, can exhibit excellent effects of improving all of productivity, processability, kneading properties and heat resistance without deterioration in the respective properties.

A rubber composition contains: at least one rubber component selected from the group consisting of an ethylene propylene diene rubber, a chloroprene rubber, a nitrile rubber, and an acrylic rubber; 1.5 to 30 parts by mass of a fluorene-modified cellulose nanofiber per 100 parts by mass of the rubber component; and 30 to 120 parts by mass of a carbon-based filler per 100 parts by mass of the rubber component. A method of producing a rubber composition comprises: kneading a dispersion of a fluorene-modified cellulose nanofiber in a process oil and a rubber component to prepare a kneaded material; and mixing a vulcanizing agent into the kneaded material.

A rubber composition contains: at least one rubber component selected from the group consisting of an ethylene propylene diene rubber, a chloroprene rubber, a nitrile rubber, and an acrylic rubber; 1.5 to 30 parts by mass of a fluorene-modified cellulose nanofiber per 100 parts by mass of the rubber component; and 30 to 120 parts by mass of a carbon-based filler per 100 parts by mass of the rubber component. A method of producing a rubber composition comprises: kneading a dispersion of a fluorene-modified cellulose nanofiber in a process oil and a rubber component to prepare a kneaded material; and mixing a vulcanizing agent into the kneaded material.

Provided are a tire tread composition comprising modified natural oil-based process oil and a tire tread manufactured using the same, and the tire tread according to the present disclosure has excellent performance while using process oil made of eco-friendly materials.