A method for producing a polymer latex, including an emulsification step of emulsifying a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer having a molecular weight distribution of 1.0 to 2.6 in an organic solvent, in water in the presence of a surfactant, to thereby obtain an emulsified liquid, wherein as the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, used are/is synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer which, when dissolved in an organic solvent to thereby be formed into a polymer solution having a viscosity at a temperature of 60 C. of 20,000 cps, have/has a solid content concentration in the range of 10 to 60% by weight.

A method for producing a polymer latex, including an emulsification step of emulsifying a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer having a molecular weight distribution of 1.0 to 2.6 in an organic solvent, in water in the presence of a surfactant, to thereby obtain an emulsified liquid, wherein as the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, used are/is synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer which, when dissolved in an organic solvent to thereby be formed into a polymer solution having a viscosity at a temperature of 60 C. of 20,000 cps, have/has a solid content concentration in the range of 10 to 60% by weight.

A synthetic polyisoprene copolymer is manufactured by stirring a synthetic polyisoprene rubber latex under the heating condition of 50 C. or higher, purifying the latex by centrifugation, adding a vinyl monomer to the purified synthetic polyisoprene rubber latex obtained and graft-copolymerizing the vinyl monomer. The synthetic polyisoprene copolymer is a copolymer in which a vinyl monomer is graft-copolymerized on the surface of synthetic polyisoprene particles, and which has a nanomatirx structure in which the synthetic polyisoprene rubber particles are dispersed in a continuous phase having a thickness of from 1 to 100 nm formed by graft chains in a phase-separated state.

A synthetic polyisoprene copolymer is manufactured by stirring a synthetic polyisoprene rubber latex under the heating condition of 50 C. or higher, purifying the latex by centrifugation, adding a vinyl monomer to the purified synthetic polyisoprene rubber latex obtained and graft-copolymerizing the vinyl monomer. The synthetic polyisoprene copolymer is a copolymer in which a vinyl monomer is graft-copolymerized on the surface of synthetic polyisoprene particles, and which has a nanomatirx structure in which the synthetic polyisoprene rubber particles are dispersed in a continuous phase having a thickness of from 1 to 100 nm formed by graft chains in a phase-separated state.

A method for producing a fluoropolymer aqueous dispersion, the method including concentrating a composition comprising a polymer (I) containing a polymerization unit (I) derived from a monomer (I) represented by the general formula (I), a fluoropolymer excluding the polymer (I), a nonionic surfactant, a fluorine-free anionic surfactant, and an aqueous medium to thereby obtain an aqueous dispersion containing the fluoropolymer,

CX.sup.1X.sup.3CX.sup.2R(CZ.sup.1Z.sup.2-A.sup.0).sub.m(I)

wherein X.sup.1 and X.sup.3 are each independently F, Cl, H, or CF.sub.3; X.sup.2 is H, F, an alkyl group, or a fluorine-containing alkyl group; A.sup.0 is an anionic group; R is a linking group; Z.sup.1 and Z.sup.2 are each independently H, F, an alkyl group, or a fluorine-containing alkyl group; and m is an integer of 1 or more.

A method for producing a fluoropolymer aqueous dispersion, the method including concentrating a composition comprising a polymer (I) containing a polymerization unit (I) derived from a monomer (I) represented by the general formula (I), a fluoropolymer excluding the polymer (I), a nonionic surfactant, a fluorine-free anionic surfactant, and an aqueous medium to thereby obtain an aqueous dispersion containing the fluoropolymer,

CX.sup.1X.sup.3CX.sup.2R(CZ.sup.1Z.sup.2-A.sup.0).sub.m(I)

wherein X.sup.1 and X.sup.3 are each independently F, Cl, H, or CF.sub.3; X.sup.2 is H, F, an alkyl group, or a fluorine-containing alkyl group; A.sup.0 is an anionic group; R is a linking group; Z.sup.1 and Z.sup.2 are each independently H, F, an alkyl group, or a fluorine-containing alkyl group; and m is an integer of 1 or more.

Methods of improving Mooney stability of a brominated elastomer comprising: neutralizing a brominated elastomer effluent with a neutralizing agent and water to form a neutralized effluent comprising a hydrocarbon solvent; removing the solvent from the neutralized effluent to form a brominated elastomer slurry; and separating a brominated elastomer from the brominated elastomer slurry, wherein a Mooney stabilizer package comprising an amine-functional hindered amine stabilizer (HAS) and an acid scavenger can be added, together or separately, before the removing step are provided herein. The acid scavenger can comprise a protonatable atom with a pKa greater than the pKa of the HAS nitrogen atom. The separated brominated elastomer can have a delta Mooney of not more than about 10 Mooney units after 7 days at 80 C. Stabilized brominated elastomer compositions can be made using this method, and articles can be made from those compositions.

A method for producing a polymer solution including a methacrylate copolymer having a weight average molecular weight of not less than 100,000, a weight average molecular weight/number average molecular weight of 1.01 to 1.8 and a glass transition temperature of not more than 40 C. and including methyl methacrylate units and alkyl (meth)acrylate units containing a C10-36 alkyl group, and a first solvent having a boiling point of not less than 200 C., through steps including a step (I) of preparing the methacrylate copolymer by polymerizing monomers in a second solvent having a boiling point of below 200 C., and a step (II) of mixing the solution from the step (I) which includes the methacrylate copolymer and the second solvent, with the first solvent, and removing the second solvent to raise the content of the first solvent to not less than 10 mass % of the polymer solution.

A method for preparing a dried powder is provided. The facility includes a first drying chamber having a heating element and a second drying chamber. A mixture of powder and diluent is introduced into the first drying chamber. A pre-dried powder is transferred from the first drying chamber into the second drying chamber. A dried powder, including a recirculated amount of powder and a discharge amount of powder, is formed in the second drying chamber. The recirculated amount of the dried powder is transferred by a conveyor device from the second drying chamber into the first drying chamber. The discharge amount of the dried powder is discharged from the second drying chamber.

A method for preparing a dried powder is provided. The facility includes a first drying chamber having a heating element and a second drying chamber. A mixture of powder and diluent is introduced into the first drying chamber. A pre-dried powder is transferred from the first drying chamber into the second drying chamber. A dried powder, including a recirculated amount of powder and a discharge amount of powder, is formed in the second drying chamber. The recirculated amount of the dried powder is transferred by a conveyor device from the second drying chamber into the first drying chamber. The discharge amount of the dried powder is discharged from the second drying chamber.