A chloroprene-based polymer, wherein: a 1H-NMR spectrum of the chloroprene-based polymer measured in a deuterochloroform solvent has a peak at 5.80 to 6.00 ppm; when an area of the peak at 5.80 to 6.00 ppm is A and an area of a peak at 4.05 to 6.00 ppm is B, A/B is 1.20/100 or less; the 1H-NMR spectrum of the chloroprene-based polymer measured in a deuterochloroform solvent has a peak at 5.40 to 5.60 ppm; when an area of the peak at 5.40 to 5.60 ppm is D and the area of the peak at 4.05 to 6.00 ppm is B, D/B is 97.20/100 or less, is provided.

A rubbery polymer extrusion dryer includes: a cylinder; a liner provided on an inner peripheral surface of the cylinder; a screw rotatably arranged in the liner; wherein the rubbery polymer extrusion dryer conveys a rubbery polymer by the screw rotating in the liner, wherein a plurality of grooves extending in a conveying direction of the rubbery polymer are formed on an inner surface of the liner, and wherein widths of the grooves are 0.1 mm or more and 2 mm or less.

A thermoplastic elastomer composition obtained by dynamically crosslinking an ethylene/-olefin/non-conjugated polymer copolymer (A), a polyolefin resin (B), a softener (C) in an amount of 1 to 200 parts by mass per 100 parts by mass of the total of the copolymer (A) and the resin (B), and a crosslinking agent (D) by the use of a batch mixer under the conditions satisfying the requirements (1) to (4).

A thermoplastic elastomer composition obtained by dynamically crosslinking an ethylene/-olefin/non-conjugated polymer copolymer (A), a polyolefin resin (B), a softener (C) in an amount of 1 to 200 parts by mass per 100 parts by mass of the total of the copolymer (A) and the resin (B), and a crosslinking agent (D) by the use of a batch mixer under the conditions satisfying the requirements (1) to (4).

The disclosure provides an anti-adhesive composition for unvulcanized rubbers which enables a reduction in anti-adhesive-induced dusting, can exhibit high anti-adhesive properties even in a small application amount, and brings about high slipperiness. The anti-adhesive composition for unvulcanized rubbers includes (A) a water-soluble polymer, (B) particles of a water-insoluble organic polymer, (C) a metal soap, (D) a surfactant and water. The anti-adhesive composition for unvulcanized rubbers includes, with respect to the whole mass of the components excluding the water, 30 mass % or more the component (A), 1-20 mass % the component (B), 20-50 mass % the component (C), and 10-20 mass % the component (D).

The disclosure provides an anti-adhesive composition for unvulcanized rubbers which enables a reduction in anti-adhesive-induced dusting, can exhibit high anti-adhesive properties even in a small application amount, and brings about high slipperiness. The anti-adhesive composition for unvulcanized rubbers includes (A) a water-soluble polymer, (B) particles of a water-insoluble organic polymer, (C) a metal soap, (D) a surfactant and water. The anti-adhesive composition for unvulcanized rubbers includes, with respect to the whole mass of the components excluding the water, 30 mass % or more the component (A), 1-20 mass % the component (B), 20-50 mass % the component (C), and 10-20 mass % the component (D).

The invention relates to a method for extracting high-quality polyisoprene by grinding plants via rotary shearing using a device comprising at least one rotor and at least one stator, into particles of size smaller than 1 mm, or grinding at a pH higher than 3 and lower than 8. This method is implemented in aqueous phase and allows the preparation of a dispersion of polyisoprene in water having a weight average molecular weight (M.sub.W) higher than 800 000 g/mol. The polyisoprene is extracted from plants and in particular from guayule (Parthenium argentatum). It is a method that is particularly heedful of the environment.

The invention relates to a method for extracting high-quality polyisoprene by grinding plants via rotary shearing using a device comprising at least one rotor and at least one stator, into particles of size smaller than 1 mm, or grinding at a pH higher than 3 and lower than 8. This method is implemented in aqueous phase and allows the preparation of a dispersion of polyisoprene in water having a weight average molecular weight (M.sub.W) higher than 800 000 g/mol. The polyisoprene is extracted from plants and in particular from guayule (Parthenium argentatum). It is a method that is particularly heedful of the environment.

The present invention provides a modified natural rubber having a good balance of improved fuel economy, heat-aging resistance, processability, and breaking resistance, and a method for producing such a rubber. The present invention also provides a tire rubber composition and a pneumatic tire which are prepared using the modified natural rubber. The present invention relates to a highly purified, modified natural rubber whose pH is adjusted to 2 to 7.

The present invention provides a modified natural rubber having a good balance of improved fuel economy, heat-aging resistance, processability, and breaking resistance, and a method for producing such a rubber. The present invention also provides a tire rubber composition and a pneumatic tire which are prepared using the modified natural rubber. The present invention relates to a highly purified, modified natural rubber whose pH is adjusted to 2 to 7.