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.

Methods for producing highly spherical particles that comprise: mixing a mixture comprising: (a) nanoclay-filled-polymer composite comprising a nanoclay dispersed in a thermoplastic polymer, (b) a carrier fluid that is immiscible with the thermoplastic polymer of the nanoclay-filled-polymer composite, optionally (c) a thermoplastic polymer not filled with a nanoclay, and optionally (d) an emulsion stabilizer at a temperature at or greater than a melting point or softening temperature of the thermoplastic polymer of the nanoclay-filled-polymer and the thermoplastic polymer, when included, to disperse the nanoclay-filled-polymer composite in the carrier fluid; cooling the mixture to below the melting point or softening temperature to form nanoclay-filled-polymer particles; and separating the nanoclay-filled-polymer particles from the carrier fluid.

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.

A process for manufacturing a masterbatch comprises the following steps: (a) bringing at least one initial polymer comprising at least one carbon-carbon unsaturation into contact with at least one 1,3-dipolar grafting agent bearing at least one nitrile oxide dipole in the presence of at least one organophosphorus additive selected from the group consisting of phosphoric acid triesters, phosphonates, phosphinates, phosphine oxides and the mixtures of these compounds, and (b) recovering the masterbatch obtained in the preceding step. The masterbatch and compositions containing it and also tires comprising such compositions are also disclosed.

The invention relates to a process for devulcanizing a vulcanized rubber mixture, comprising the following steps: A) providing or producing a vulcanized rubber mixture, B) comminuting the vulcanized rubber mixture to a granular material composed of vulcanized rubber particles, where the vulcanized rubber particles have a maximum particle diameter of 100 mm, C) extruding the vulcanized rubber particles produced in step B) in a twin-screw extruder at a shear rate of less than 100 s.sup.−1, where the temperature of the vulcanized rubber particles during extrusion is less than 200° C., to give a devulcanized rubber mixture having a temperature above 100° C., D) cooling the devulcanized rubber mixture in a further kneading unit, so as to give a devulcanized rubber mixture having a temperature in the range from 50° C. to 100° C. The invention further relates to an apparatus for performing the process and to the use of the apparatus for devulcanization of a vulcanized rubber mixture.

A continuous process for making a pressure-sensitive adhesive is disclosed. A mixture comprising natural rubber having a Mooney viscosity of 85 to 100, a tackifier, a filler, and 0.1 to 5 wt. % of an added C.sub.12-C.sub.24 fatty acid based on the amount of mixture is masticated in a first section of a single- or twin-screw extruder. Mastication of the mixture continues in at least one subsequent extruder section in the presence of additional tackifier. The product is a homogeneous, reduced-viscosity pressure-sensitive adhesive. The minor proportion of added C.sub.12-C.sub.24 fatty acid aids mastication of the rubber and enables high throughput without addition of peptizers. Duct tapes made from the adhesives display improved adhesion to steel, better adhesion bond strength, and enhanced seven-day clean removability from even difficult substrates such as marble or ceramic tile.

An ultra-light graphene-rubber foam particle for soles is prepared from, by weight, 60-65 parts of natural rubber, 8-12 parts of isoprene rubber, 8-12 parts of butadiene rubber, 6-8 parts of styrene butadiene rubber, 0.8-1.0 parts of modified graphene, 0.08-0.12 parts of poly(N-vinylacetamide), 0.8-1.0 parts of silicone oil, 3.0-3.5 parts of inorganic nano-particles, 1.2-1.5 parts of activated zinc oxide, 0.8-1.0 parts of zinc stearate, 1.0-1.2 parts of stearic acid, 0.8-1.0 parts of cross-linking agents, 2.0-3.0 parts of flow promotors, and 1.5-1.8 parts of foaming agents. According to the invention, the modified graphene is uniformly dispersed into the rubber materials, so that the ultra-light graphene-rubber foam particle has good thermal stability, wear resistance and tensile strength, the permanent compressive-deformation performance and thermal contraction resistance are improved, and the weight is reduced by over 50%.

A vulcanizing agent-modified graphene prepared through an in-situ chemical deposition process and a controllable crosslinked natural rubber composite containing the same. In the preparation of the vulcanizing agent-modified graphene, graphene oxide is coated on a spherical thermal-conductive functional particle through the chemical bonding to obtain a 3D graphene particle; and a vulcanizing agent is adsorbed on the 3D graphene particle through π-π conjugation by an in-situ chemical deposition process to obtain a vulcanizing agent-modified graphene particle. Further, the vulcanizing agent-modified graphene particle is mixed with natural rubber latex, and undergoes synergistic coagulation in water to form a graphene masterbatch, which is further processed into the controllable crosslinked natural rubber composite by adding a certain amount of natural rubber block, rubber additive and reinforcing filler.

The rubber-plastic composite foamed material of the present invention is made by mixing and foaming a plurality of components including 100 parts by weight of rubber, 5-70 parts by weight of hollow glass microspheres, 2-25 parts by weight of carbon black, 10-40 parts by weight of softening oil, 10-30 parts by weight of sulfur ointment, 0.5-5 parts by weight of antioxidant, 0.5-10 parts by weight of crosslinking agent and 2-12 parts by weight of foaming agent. By including hollow glass microspheres into the composition, the rubber-plastic composite foamed material of the present invention exhibits better compression resistance and heat retention.

Disclosed is a rubber composition which suppresses poor mixing or poor dispersion from occurring between an organic polymer material derived from natural rubber and an inorganic material such as silica and exhibits excellent viscoelastic properties, and a silane coupling agent composition used in the same. Also disclosed is a silane coupling agent composition comprising a protein modifying agent and a silane compound represented by Formula (1):

##STR00001##

wherein each of the variables is as defined herein.