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US 12,258,427 B2Granted
Processes for increasing the molecular weight of guayule natural rubber
AssigneeBridgestone Corporation
InventorsRobert W. White, Michael R. Hartzell
Life of this patent
Estimating the term…
Abstract
Disclosed herein are process for increasing the molecular weight of guayule natural rubber that is solubilized in an organic solvent solution. The processes utilize shear desolventizing to achieve the increase in molecular weight.
Claims21
A process for increasing the molecular weight of solubilized guayule natural rubber comprising
- a. providing an organic solvent-guayule natural rubber solution comprising (i) guayule natural rubber having an initial Mw in grams/mole, and (ii) optionally guayule resin, wherein the organic solvent-guayule natural rubber solution of (a) includes about 5 to about 40 weight % guayule natural rubber, based upon the total weight of the organic solvent-guayule natural rubber solution;
- and
- b. subjecting the organic solvent-guayule natural rubber solution of (a) to shear desolventizing under conditions including at least one of (i) a temperature of about 160 to about 280° F., or (ii) a pressure of about 29 inches Hg absolute to about 0.1 inches Hg absolute or about 100 kPa absolute to about 0.3 kPa absolute,
- thereby producing a desolventized guayule natural rubber having 1 weight % or less organic solvent, and an Mw in grams/mole that is at least 10% higher than the initial Mw.
1 more element
A process for increasing the molecular weight of solubilized guayule natural rubber comprising:
- a. providing an organic solvent-guayule natural rubber solution comprising (i) guayule natural rubber having an initial Mw in grams/mole, and (ii) optionally guayule resin, wherein the organic solvent-guayule natural rubber solution of (a) includes about 5 to about 40 weight % guayule natural rubber, based upon the total weight of the organic solvent-guayule natural rubber solution;
- and
- b. subjecting the organic solvent-guayule natural rubber solution of (a) to shear desolventizing under conditions including at least one of (i) a temperature of about 160 to about 280° F., or (ii) a pressure of about 29 inches Hg absolute to about 0.1 inches Hg absolute or about 100 kPa absolute to about 0.3 kPa absolute,
- thereby producing a desolventized guayule natural rubber having 1 weight % or less organic solvent, and an Mw in grams/mole that is at least 50,000 grams/mole higher than the initial Mw of the guayule natural rubber of (a).
1 more element
Dependencies are inferred from the claim text.