The Firestone Tire & Rubber Company

Shrikant R Malani

Frank J Clark

William M Cole

Jung W Kang

David M Roggeman

Steven L Fenske

David J Serbin

Joanne L Beattie

A process for extracting resin and rubber from guayule plants utilizing a portion of recycled miscella and a fresh solvent system. An expression step is applied to the plants to enhance recovery of resin and rubber extract. The solvent system is preferably an organic polar solvent and a hydrocarbon solvent for rubber for simultaneous resin and rubber extraction containing at least 50% by weight of the hydrocarbon solvent. The process can be a one-step method wherein resin and rubber are generally simultaneously extracted.

Use of rubber solvent-resin solvent and miscella mixtures for

A process and product thereof for densifying guayule shrubs by compression and forming a densified pellet. The densified pellet substantially maintains its molecular weight during storage over a period of weeks without the aid of any inert gas blanket or the like.

Storage of guayule by densification

A method for preparing high cis-1,4 polybutadiene by a continuous process which involves the continuous polymerization of 1,3-butadiene in solution under adiabatic conditions is provided. The method comprises the steps of: (I) feeding continuously to a single agitated polymerization reactor: (a) a monomer stream comprising 1,3-butadiene in a hydrocarbon solvent; (b) a preformed .pi. allyl catalyst stream formed by admixing a carboxylated metal oxy borate compound represented by the formulae (RCOOMO).sub.3 B or (ROCOOMO).sub.2 B-OR' wherein R and R' are alkyl radicals containing from 7 to 17 carbon atoms and M is nickel or cobalt, an organo aluminum compound, an alcohol, a small amount of 1,3-butadiene and a hydrocarbon solvent; and (c) a cocatalyst stream comprising a boron trifluoride complex with an alcohol; and (II) withdrawing continuously from said reactor high cis-1,4 polybutadiene at the same rate as said monomer, preformed catalyst and cocatalyst streams are fed to the reactor. In an additional embodiment of the invention, a method of preparing a preformed .pi. allyl catalyst having improved stability and solubility in hydrocarbon solvent is provided. High cis-1,4 polybutadiene polymers produced by the method of the invention have good green strength and tack and may be used as tire rubbers and impact modifiers for plastics.

Continuous method for preparing high cis-1,4 polybutadiene

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Akron, OH, United States of America

Shrikant R Malani