A method for stabilizing a natural rubber such as guayule. The method includes the step of introducing at least one of an Extraction Curves for Guayule Rubber Samples amine and a phenolic anti-oxidant, such as MADA, to a latex form of the rubber under conditions such that the anti-oxidant becomes chemically bound to the rubber. The method includes the further step of subsequently treating the rubber to remove at least a substantial portion of entrained resins. The method can yield a rubber composition of, for example, guayule rubber and including an anti-oxidant chemically bound thereto. The resultant rubber can be suitable for use in tire construction.

A method for stabilizing a natural rubber such as guayule. The method includes the step of introducing at least one of an Extraction Curves for Guayule Rubber Samples amine and a phenolic anti-oxidant, such as MADA, to a latex form of the rubber under conditions such that the anti-oxidant becomes chemically bound to the rubber. The method includes the further step of subsequently treating the rubber to remove at least a substantial portion of entrained resins. The method can yield a rubber composition of, for example, guayule rubber and including an anti-oxidant chemically bound thereto. The resultant rubber can be suitable for use in tire construction.

A tire manufacturing method includes making a master batch, using the master batch to make a rubber composition, and making a green tire. The master batch is made wherein a carbon-black-containing pre-coagulation rubber latex is coagulated to obtain a coagulum; a compound according to Formula (I) is added to the water-containing coagulum; ##STR00001##
wherein R.sup.1 and R.sup.2 each indicates a hydrogen atom, an alkyl group having 1 to 20 carbons, an alkenyl group having 1 to 20 carbons, or an alkynyl group having 1 to 20 carbons, R.sup.1 and R.sup.2 may be the same or different, and M.sup.+ indicates sodium ion, potassium ion, or lithium ion; and the compound according to Formula (I) is dispersed within the coagulum. The green tire is provided with unvulcanized rubber sheeting made up of the rubber composition, chafer(s), carcass ply or plies, and bead filler(s).

A tire manufacturing method includes making a master batch, using the master batch to make a rubber composition, and making a green tire. The master batch is made wherein a carbon-black-containing pre-coagulation rubber latex is coagulated to obtain a coagulum; a compound according to Formula (I) is added to the water-containing coagulum; ##STR00001##
wherein R.sup.1 and R.sup.2 each indicates a hydrogen atom, an alkyl group having 1 to 20 carbons, an alkenyl group having 1 to 20 carbons, or an alkynyl group having 1 to 20 carbons, R.sup.1 and R.sup.2 may be the same or different, and M.sup.+ indicates sodium ion, potassium ion, or lithium ion; and the compound according to Formula (I) is dispersed within the coagulum. The green tire is provided with unvulcanized rubber sheeting made up of the rubber composition, chafer(s), carcass ply or plies, and bead filler(s).

The present invention relates to a method for obtaining rubber from rubber-containing plant material, the method comprising the steps of subjecting a composition comprising rubber-containing plant material and a fermentation culture to conditions allowing anaerobic fermentation, wherein the composition preferably has a water content of less than 95 wt. %. The fermentation preferably does not involve movement of the rubber-containing plant material (or parts thereof), and preferably the fermentation is performed in the absence of oxygen ventilation. Additionally, it is preferred that the fermentation culture is cycled through the composition by percolation. A further step of the method involves obtaining the rubber from the composition.

The present invention relates to a method for obtaining rubber from rubber-containing plant material, the method comprising the steps of subjecting a composition comprising rubber-containing plant material and a fermentation culture to conditions allowing anaerobic fermentation, wherein the composition preferably has a water content of less than 95 wt. %. The fermentation preferably does not involve movement of the rubber-containing plant material (or parts thereof), and preferably the fermentation is performed in the absence of oxygen ventilation. Additionally, it is preferred that the fermentation culture is cycled through the composition by percolation. A further step of the method involves obtaining the rubber from the composition.

A nitrile copolymer rubber composition has a nitrile copolymer rubber (A) containing 22 to 45 wt % of ,-ethylenically unsaturated nitrile monomer units and a vinyl chloride resin (B) having an average polymerization degree of 1200 to 2200, wherein a ratio of content of the vinyl chloride resin (B) with respect to 100 parts by weight of the nitrile copolymer rubber (A) is 70 to 140 parts by weight.

An acrylic rubber has a residual calcium content of 60 wt ppm or less and a polymer pH of 7.0 or less, and preferably has a carboxyl group.

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.

Systems and methods for extracting useful by-products and natural rubber from non-Hevea rubber bearing plants are disclosed.