Provided is a fiber for rubber reinforcement that can be produced using a bio-derived raw material and hardly breaks even when compounded with a rubber material. A first fiber for rubber reinforcement uses a protein fiber containing a hydrophobic protein. A second fiber for rubber reinforcement uses a protein fiber having an initial tensile modulus of elasticity of 2.0 GPa or more when wet. These fibers for rubber reinforcement preferably have a coating layer made of a water-based adhesive composition on the surface thereof.

A water-based hydrogel polymer coating and a method of application to natural rubber or other elastomeric latex products are provided. The water-based hydrogel polymer is mixed with a blend of at least one elastomeric material to provide a hydrogel polymer blend composition. The water-based hydrogel polymer blend composition is applied in a single application to an elastomeric article, such as gloves, without additional solvents in the polymer blend composition and without a separate acid or chemical priming step. The water-based hydrogel coating herein provides increased lubricity to facilitate improved wet and dry donning of the elastomeric article.

The present invention relates to a method (100) for preparing a pre-treated synthetic latex emulsion, the method comprising the steps of, adding a synthetic latex into a tank (101), characterized by mixing a surfactant with the synthetic latex in the tank (102), adding alkaline material into a mixture of the synthetic latex added with the surfactant (103), adding a reactive metal ion into the mixture (104) and continue mixing the mixture for at least two hours (105), wherein the reactive metal ion is obtained by heating a metal oxide or metal hydroxide with supply of alkaline material at 120 to 180° C.

A masterbatch manufacturing method comprises: an operation in which carbon black is dispersed in dispersion medium in presence of a surface active agent having an aromatic ring to prepare a carbon black slurry; an operation in which at least the carbon black slurry and a rubber latex are mixed to prepare a liquid mixture; and an operation in which the liquid mixture is coagulated.

A problem is to provide a method for manufacturing a wet rubber masterbatch that will serve as raw material for vulcanized rubber having excellent tensile strength and tear strength and that will permit wet rubber masterbatch to be molded in a short time.

A method comprising an operation in which a collection of granules comprising a plurality of granular coagula are obtained from a liquid mixture comprising filler and rubber latex solution, and an operation in which the collection of granules is compressed under conditions satisfying Formula I, makes it possible to cause a wet rubber masterbatch capable of serving as raw material for vulcanized rubber having excellent tensile strength and tear strength to be molded in a short time.

3≦P×Da≦500  FORMULA I

(P indicates pressure (kgf/cm.sup.2) applied to the collection of granules. Da indicates granule diameter (mm) of the granular coagula.)

The present invention relates to a composition for preparation of latex pads, comprising natural latex, artificial latex, sliver nanoparticles, zinc oxide nanoparticles, and active carbon mixed in a specified proportion. The present invention also provides a method for manufacturing latex pads from the composition.

The present invention provides a cosmetic composition carrier comprising a latex foam having a density of 0.05-0.2 g/cm.sup.3 and a cosmetic product comprising same. The cosmetic composition carrier according to the present invention has excellent filling, holding, and discharge capabilities with respect to a liquid cosmetic, has excellent antibacterial activity, can be filled with, hold, and discharge liquid cosmetic compositions in a wide range of low to high viscosities, thus allows excellent color expression and uniform application without caking when a liquid cosmetic composition held in the cosmetic composition carrier is applied to the skin, and allows the application of the liquid cosmetic composition to a portable container.

A masterbatch manufacturing method in accordance with the present disclosure comprises an operation in which pre-coagulation rubber latex comprising filler is coagulated to obtain a coagulum; an operation in which the coagulum is dewatered; and an operation in which the dewatered coagulum is plasticized as it is dried by means of an extruder; wherein, during the operation in which the dewatered coagulum is plasticized as it is dried, the coagulum comprises a peptizing agent.

Methods to prepare elastomer compounds are described that include dry mixing at least one additive to an elastomer composite masterbatch at low temperatures over a shortened mixing cycle with reduced energy consumption. The elastomer composite masterbatch is produced in a liquid masterbatch process. The resulting elastomer compounds are further described as well as property improvements that can be achieved.

A method for producing a rubber wet master batch is disclosed including: producing a carbon black-containing rubber latex solution by mixing carbon black, a dispersion solvent and a rubber latex solution; producing a carbon black-containing rubber coagulum by coagulating the thus-obtained carbon black-containing rubber latex solution; and producing a rubber wet master batch by dehydrating and drying the thus-obtained carbon black-containing rubber coagulum. With respect to this method for producing a rubber wet master batch, the carbon black satisfies conditions such that: the DBP oil absorption is 105-230 mL/100 g; STSA is 90-205 m.sup.2/g; and the value obtained by subtracting the value of STSA from the value of DBP oil absorption is 15 or more. This method for producing a rubber wet master batch enables the achievement of a vulcanized rubber that has wear resistance and low heat generation properties.