The Firestone Tire & Rubber Company

Edward L Kay

Richard Gutierrez

Kenneth B Roskos

Grant Crane

David F Lawson

Delmar F Lohr, Jr

David J Serbin

Walter R Hausch

Wendall R Conard

Salts generally act as reinforcing compounds in polyurethane compositions. Salts containing a free-amine function generally increase the low-strain moduli more than salts which lack such free-amine functions or are neutral. The salts are generally formed by reacting a basic nitrogen function compound such as a monoamine or a diamine with a mono or a dicarboxylic acid.

Polyurethanes containing amine salts

A process for achieving a high yield of rubber and/or resin from rubber containing plants such as guayule plants by crushing the plants, forming a slurry with a solvent and fine grinding said slurry with a high shear mixer. The time required by the process is very short in comparison with prior art techniques.

Fine grinding guayule shrub-solvent slurry

Urethane elastomers are produced by reacting a prepolymer with a chain extender or cure agent in the presence of limited amounts of water without adverse effects on the physical properties of the cured polyurethane.

Water as a partial extender in polyurethane formulations

A process for extracting rubber and/or resin from rubber containing plants such as guayule utilizing a monophase mixture of an organic polar solvent and a hydrocarbon solvent.

Extraction of rubber and/or resin from rubber containing plants with a

Synthetic rubber is thermooxidatively stabilized with guayule resin. The guayule resin imparts favorable stabilization as evidenced by minimum bulk viscosity changes and minimum gel formation, especially with styrene-butadiene synthetic elastomers prepared by emulsion or hydrocarbon solvent techniques.

Synthetic rubber with guayule resin stabilization

Urethane compositions generally free of phase separation patterns and flow lines are produced. One method includes the utilization of a nucleating compound which is generally added to a urethane prepolymer before any chain extension thereof. Examples of nucleating agents include urethanes, ureas and allophanates such as carboxylic acids, organic acid and anhydrides, amides, imides and the like. Another method includes adding a very small initial incremental amount of a curing agent to the prepolymer with an insoluble product being produced thereby and subsequently adding the remainder of the curing agent.

Nucleation of urethane compositions

A process and urethane composition for making urethane prepolymers from a polyisocyanate and blends of two or more urethane intermediates. The prepolymers so produced when cured have improved physical properties such as high low strain modulus and tensile strength relative to cured polyurethanes prepared from a mixture of prepolymers prepared by reacting a polyisocyanate with the component intermediates and subsequently blending the prepolymers.

Polyurethane prepolymer comprising the reaction product of at least two

Urethane elastomers are produced by initially adding at least one incremental amount of a curing agent to a urethane prepolymer, having free polyisocyanate therein. Generally, free polyisocyanate-curing agent adducts are precipitated. Subsequently, the remaining amount of curing agent is added. Chain extension, accordingly, is favored which produces hard segment domains more evenly distributed in the polymer chain and imparts improved physical properties such as hardness, tear strength and high-low strain modulus.

Urethane compositions

Urethane compositions are prepared which contain preformed adducts. The preformed adducts are prepared by reacting a polyisocyanate with various polyols or amine analogs thereof whereby a product insoluble in the urethane prepolymer is produced. An intermediate polyol is added to produce a prepolymer. The cured urethane compositions have high low-strain moduli.

Urethane compositions prepared via preformed adducts

Combinations of para-phenylene diamines and para di(nitroso) arenes act synergistically in guayule rubber-based compositions to protect them against oxidative degradation. A typically useful diamine is N-(1,3-dimethylbutyl)-N'-phenyl-phenyl-p-phenylene diamine and a useful arene is para-di(nitroso)benzene. Vulcanizable compositions, as well as articles made therefrom, are within the scope of the invention.

Synergistic additive combination for guayule rubber stabilization

Elastomers such as guayule rubber is stabilized by the addition of an alkyl, cycloalkyl or alkyl substituted cycloalkyl phenyl-phenylenediamine compound with an alkyl, cycloalkyl or alkyl substituted cycloalkyl phosphite compound which, in combination, yield an unexpectant and synergistic result.

Stabilization of elastomers with aliphatic-phenyl diamines and aliphatic

Tackifying agents for rubber comprising at least one chemically or physically treated guayule resin fraction are disclosed. Physical treatments include vacuum deoiling, steam stripping deoiling, hexane deoiling, while chemical treatments include formaldehyde reaction, phenol/formaldehyde reaction, urea formaldehyde reaction, acid reaction and sulphur reaction. Untreated guayule resin fractions can also be used. Vulcanized and unvulcanized rubber compositions containing guayule resin derived tackifying agents as well as articles made therefrom are also disclosed.

Rubber additives derived from guayule resins and compositions containing

A method of storing guayule and guayule-like plant material prior to processing which comprises mixing the material in communited form with at least one essentially water-free organic liquid to form a slurry in which the material is protected from contact with oxygen and storing said slurry for at least about 24 hours is disclosed. Preferably, the organic liquid is an alcohol, ether, ester, ketone, or hydrocarbon and optionally the slurry also contains an oxidation stabilizer.

Methods for storage of guayule plant material

Rubber, hydrocarbons, i.e., resins, and other useful by-products are extracted from shrubs such as guayule and guayule-like shrubs by a procedure wherein the shrub, after being comminuted, is processed in an aqueous and/or a non-aqueous system. An optional water treatment step can be used to remove water solubles and/or facilitate processing and achieve increased yield of desired by-products.

Process for extracting rubber and by-products from guayule and

Rubber, hydrocarbons, i.e., resins, and other useful by-products are extracted, recovered and isolated from shrubs such as guayule and guayule-like shrubs by a procedure wherein the entire non-defoliated shrub, after being comminuted, is processed in an aqueous and/or a non-aqueous system. An optional water treatment step can be used to remove water solubles and/or facilitate processing and achieve increased yield of desired by-products.

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Akron, OH, United States of America

Edward L Kay