Processes for recovering rubber from natural rubber latex
AssigneeBridgestone Corporation
InventorsWilliam M Cole, Georg G. A. Bohm, Walter Tomaszewski, Yingyi Huang
Life of this patent
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Abstract
Processes for recovering natural rubber from an aqueous natural rubber latex that contains extractables and one or more additives and that is essentially free of lignocellulosic plant material are described. Natural rubber in the latex is separated from the water. Preferably, the amount of non-rubber extractables in the natural rubber is reduced by one or more extraction steps yielding a dried natural rubber.
Claims19
A process for recovering rubber from an aqueous non-Hevea natural rubber latex that contains natural rubber, water, extractables, and one or more additives, and is essentially free of lignocellulosic plant material, comprising the steps of:
- contacting the latex with a separating solvent composition comprising at least one hydrocarbon solvent in an amount of 5% to 60% by weight and at least one organic polar solvent in an amount of 40 to 95% by weight whereby at least 75% of the natural rubber is separated from the water and a solution having a viscous rubber phase containing natural rubber and a reduced amount of extractables is formed;
- isolating the viscous rubber phase;
- and
- drying the viscous rubber phase to create a resultant natural rubber
- wherein the resultant natural rubber has an amount of acetone extractables of 5% by weight or less.
A process for recovering rubber from an aqueous non-Hevea natural rubber latex that contains natural rubber, water, extractables, and one or more additives, and is essentially free of lignocellulosic plant material, comprising the steps of:
- contacting the latex with a separating solvent composition comprising hexane or cyclohexane in an amount of 5% to 60% by weight and acetone in an amount of 40 to 95% by weight whereby at least 75% of the natural rubber is separated from the water and a solution having a viscous rubber phase containing natural rubber and a reduced amount of extractables is formed;
- isolating the viscous rubber phase;
- and
- drying the viscous rubber phase to create a resultant natural rubber
- wherein the resultant natural rubber has an amount of acetone extractables of 5% by weight or less.
A process for recovering rubber from an aqueous non-Hevea natural rubber latex that contains natural rubber, water, extractables, and one or more additives, and is essentially free of lignocellulosic plant material, comprising the steps of:
- contacting the latex with a separating solvent composition comprising at least one hydrocarbon solvent in an amount of 5% to 60% by weight and at least one organic polar solvent in an amount of 40% to 95% by weight whereby at least 75% of the natural rubber is separated from the water and a solution having a viscous rubber phase containing natural rubber and a reduced amount of extractables is formed, wherein the weight ratio of separating solvent composition to latex is 100:1 to 1:1;
- isolating the viscous rubber phase;
- contacting the viscous rubber phase with at least one extracting solvent composition, wherein said at least one extracting solvent composition comprises at least one organic polar solvent;
- and
- drying the viscous rubber phase to create a resultant natural rubber
- wherein the resultant natural rubber has an amount of acetone extractables of 5% by weight or less.
Dependencies are inferred from the claim text.