A production method for a cyclic olefin copolymer which is capable of efficiently producing a cyclic olefin copolymer by copolymerizing monomers including a norbornene monomer and ethylene while suppressing the formation of a polyethylene-like impurity, and a catalyst composition for the copolymerization of a norbornene monomer and ethylene. Monomers including a norbornene monomer and ethylene are polymerized in the presence of a metal-containing catalyst, and the metal-containing catalyst has a structure in which a nitrogen atom is bonded to a transition metal of Group 4 of the periodic table and an atom of Group 15 of the periodic table.

A production method for a cyclic olefin copolymer which is capable of efficiently producing a cyclic olefin copolymer by copolymerizing monomers including a norbornene monomer and ethylene while suppressing the formation of a polyethylene-like impurity, and a catalyst composition for the copolymerization of a norbornene monomer and ethylene. Monomers including a norbornene monomer and ethylene are polymerized in the presence of a metal-containing catalyst, and the metal-containing catalyst has a structure in which a nitrogen atom is bonded to a transition metal of Group 4 of the periodic table and an atom of Group 15 of the periodic table.

A latex composition including a latex (A) of a diene rubber (a) having a weight average molecular weight of 50,000 or more and 1,000,000 or less and containing an ethylenically unsaturated acid monomer unit; and a latex (B) of a diene rubber (b) having a weight average molecular weight of 500 or more and less than 50,000 and containing an ethylenically unsaturated acid monomer unit.

A latex composition including a latex (A) of a diene rubber (a) having a weight average molecular weight of 50,000 or more and 1,000,000 or less and containing an ethylenically unsaturated acid monomer unit; and a latex (B) of a diene rubber (b) having a weight average molecular weight of 500 or more and less than 50,000 and containing an ethylenically unsaturated acid monomer unit.

A carboxylic acid-modified nitrile-based copolymer latex includes a carboxylic acid-modified nitrile-based copolymer including: 65.5 wt % to 82.5 wt % of a conjugated diene-based monomer-derived unit, 15 wt % to 30 wt % of an ethylenic unsaturated nitrile-based monomer-derived unit, and 2.5 wt % to 4.5 wt % of an ethylenic unsaturated acid monomer-derived unit, wherein the carboxylic acid-modified nitrile-based copolymer latex satisfies General Formula 1:

1.0 mm.sup.2/s≤CV.sub.0≤3.0 mm.sup.2/s  [General Formula 1]

wherein CV.sub.0 represents a capillary viscosity of the carboxylic acid-modified nitrile-based copolymer latex which is measured in a swollen state in a methyl ethyl ketone solvent.

A carboxylic acid-modified nitrile-based copolymer latex includes a carboxylic acid-modified nitrile-based copolymer including: 65.5 wt % to 82.5 wt % of a conjugated diene-based monomer-derived unit, 15 wt % to 30 wt % of an ethylenic unsaturated nitrile-based monomer-derived unit, and 2.5 wt % to 4.5 wt % of an ethylenic unsaturated acid monomer-derived unit, wherein the carboxylic acid-modified nitrile-based copolymer latex satisfies General Formula 1:

1.0 mm.sup.2/s≤CV.sub.0≤3.0 mm.sup.2/s  [General Formula 1]

wherein CV.sub.0 represents a capillary viscosity of the carboxylic acid-modified nitrile-based copolymer latex which is measured in a swollen state in a methyl ethyl ketone solvent.

The present invention provides a method for controlling Mooney viscosity of peroxide-cured fluororubber. The method comprises: adding an initiator solution in a continuous supplementary manner during the emulsion polymerization process of a peroxide-cured fluororubber until 5 to 10 minutes before the end of the polymerization reaction; wherein the amount of the initiator solution added initially is 0.1% to 0.5% of the total amount of the polymerization monomer dry materials, and the amount of the initiator solution continuously supplemented is 0.1% to 2% of the total amount of the polymerization monomer dry materials, based on the initiator. The present invention effectively controls the Mooney viscosity value of the peroxide-cured fluororubber within the desired range with small fluctuations by controlling the amount and the manner of addition of the initiator, thereby obtaining a peroxide-cured fluororubber with stable and controllable quality. Moreover, the present invention does not need to add a chain transfer agent, which reduces the amount of additives in the polymerization process, and meanwhile improves the reaction activity of the polymerization system, effectively shortens the time for polymerization, and is beneficial to industrialized production.

The present invention provides a method for controlling Mooney viscosity of peroxide-cured fluororubber. The method comprises: adding an initiator solution in a continuous supplementary manner during the emulsion polymerization process of a peroxide-cured fluororubber until 5 to 10 minutes before the end of the polymerization reaction; wherein the amount of the initiator solution added initially is 0.1% to 0.5% of the total amount of the polymerization monomer dry materials, and the amount of the initiator solution continuously supplemented is 0.1% to 2% of the total amount of the polymerization monomer dry materials, based on the initiator. The present invention effectively controls the Mooney viscosity value of the peroxide-cured fluororubber within the desired range with small fluctuations by controlling the amount and the manner of addition of the initiator, thereby obtaining a peroxide-cured fluororubber with stable and controllable quality. Moreover, the present invention does not need to add a chain transfer agent, which reduces the amount of additives in the polymerization process, and meanwhile improves the reaction activity of the polymerization system, effectively shortens the time for polymerization, and is beneficial to industrialized production.

The present disclosure provides a method of preparing a vinyl chloride-based polymer, and the method provides excellent productivity while having reduced amount of a volatile organic compound generated so as to provide the vinyl chloride-based polymer suitable for an eco-friendly material, and improved foaming and viscosity properties of a plastisol including the prepared polymer, by adding a carbonate-based metal salt and a transition metal catalyst together, and controlling input time and amount of the transition metal catalyst.

The present disclosure provides a method of preparing a vinyl chloride-based polymer, and the method provides excellent productivity while having reduced amount of a volatile organic compound generated so as to provide the vinyl chloride-based polymer suitable for an eco-friendly material, and improved foaming and viscosity properties of a plastisol including the prepared polymer, by adding a carbonate-based metal salt and a transition metal catalyst together, and controlling input time and amount of the transition metal catalyst.