A masterbatch manufacturing method comprises an operation in which at least a filler slurry and a natural rubber latex are mixed to prepare a liquid mixture, and an operation in which a coagulant is added to the liquid mixture so as to cause pH to be not less than 5.0 but less than 8.0.

A masterbatch manufacturing method comprises an operation in which at least a filler slurry and a natural rubber latex are mixed to prepare a liquid mixture, and an operation in which a coagulant is added to the liquid mixture so as to cause pH to be not less than 5.0 but less than 8.0.

The present invention addresses the problem of providing an emulsion having excellent emulsion stability and excellent coagulability (salting-out properties) in manufacturing of an acrylic rubber. The present invention provides an acrylic emulsion containing an acrylic polymer having an average particle diameter of 150-300 nm in a step for emulsion-polymerizing a monomer in manufacturing of an acrylic rubber.

The present invention addresses the problem of providing an emulsion having excellent emulsion stability and excellent coagulability (salting-out properties) in manufacturing of an acrylic rubber. The present invention provides an acrylic emulsion containing an acrylic polymer having an average particle diameter of 150-300 nm in a step for emulsion-polymerizing a monomer in manufacturing of an acrylic rubber.

A method for producing a nitrile rubber, includes recovering a nitrile rubber from a latex of nitrile rubber by continuously feeding the latex of nitrile rubber and a coagulant into an extruder including a screw disposed inside a barrel to be rotatably driven, wherein the latex of nitrile rubber fed into the extruder contains 0.1 to 3 parts by weight of a hindered phenol-based antiaging agent having a molecular weight of 300 to 3000 relative to 100 parts by weight of the nitrile rubber.

A method for producing a nitrile rubber, includes recovering a nitrile rubber from a latex of nitrile rubber by continuously feeding the latex of nitrile rubber and a coagulant into an extruder including a screw disposed inside a barrel to be rotatably driven, wherein the latex of nitrile rubber fed into the extruder contains 0.1 to 3 parts by weight of a hindered phenol-based antiaging agent having a molecular weight of 300 to 3000 relative to 100 parts by weight of the nitrile rubber.

What are provided are colour-stable, low-salt nitrile rubbers and a process for production thereof under specific conditions for the coagulation and/or washing of the nitrite rubber. Additionally obtainable are the corresponding volcanizable mixtures based on this nitrile rubber, a process for producing vulcanizates from these mixtures and the resultant vulcanizates having excellent processing properties.

What are provided are colour-stable, low-salt nitrile rubbers and a process for production thereof under specific conditions for the coagulation and/or washing of the nitrite rubber. Additionally obtainable are the corresponding volcanizable mixtures based on this nitrile rubber, a process for producing vulcanizates from these mixtures and the resultant vulcanizates having excellent processing properties.

An animal toy is provided constructed from a latex or natural rubber material and formed into a ball. The ball is formed of an aggregate of particulate material that are bound together to form a substantially non-hollow construction. Pieces of latex are joined together to form balls, and the balls may be pressed together and constructed by hand or, alternatively, pressed into molds. By constructing the balls by hand, no two balls, even balls of similar size, are identical. Each ball has irregular outer surface that forms a variety of resilient protuberances that provide beneficial oral hygiene effects when chewed or rubbed against the teeth.

An animal toy is provided constructed from a latex or natural rubber material and formed into a ball. The ball is formed of an aggregate of particulate material that are bound together to form a substantially non-hollow construction. Pieces of latex are joined together to form balls, and the balls may be pressed together and constructed by hand or, alternatively, pressed into molds. By constructing the balls by hand, no two balls, even balls of similar size, are identical. Each ball has irregular outer surface that forms a variety of resilient protuberances that provide beneficial oral hygiene effects when chewed or rubbed against the teeth.