The Upjohn Co.

The Dow Chemical Company

Peter S Carleton

Harold E Reymore, Jr

James H Ewen, Jr

Louis M Alberino

Douglas P Waszeciak

A process for the preparation of molded high strength composites comprising fibrous reinforcing material impregnated with a reaction injection molded polyisocyanurate resin. The process comprises first evacuating a mold containing the fibrous reinforcing material said mold equipped with means for accepting an overflow volume of the resin. The mold system is pressurized prior to gelation causing the overflow volume to be forced into a final volume. The molded composites have a high flexural moduli, good physical properties, low void content and smooth surface.

Method for making mat-molded rim parts

A process is provided for the preparation of hydroquinone by oxidizing a phenol having in the paraposition a 1-cycloalkenyl or .alpha.-methylene-(alkyl or aralkyl) group. The oxidation is carried out using hydrogen peroxide or a hydrocarbyl peroxide in the presence of an inert solvent and a catalytic amount of a strong acid which is not oxidized by the peroxide. The other product of the reaction is the ketone derived by oxidation of the para-substituent in the starting phenol, e.g. p-isopropenylphenol gives hydroquinone and acetone. The reaction forms a particularly convenient route for conversion of phenol to hydroquinone in that phenol is condensed with acetone to bisphenol A, the latter is degraded by alkaline hydrolysis to a mixture of phenol and p-isopropenylphenol, which latter is subjected, without separation, to the above process to give a mixture of hydroquinone, phenol, and acetone. The acetone and phenol are recovered and used in the preparation of bisphenol A thereby starting a new cycle of conversion.

Process for preparing hydroquinone and acetone

Novel solid polyisocyanurate polymers are disclosed which comprise the reaction product of an organic polyisocyanate, a trimerization catalyst and a polyol combination comprising from about 0.025 to about 0.15 equivalent and about 0.05 to about 0.25 equivalent, per equivalent of polyisocyanate, respectively of a polypropyleneoxy triol having an equivalent weight of from about 750 to about 1500 and ethylene glycol. Although containing a higher proportion of polyurethane linkages than those polyisocyanurates containing the polypropyleneoxy triol alone, the polymers of the invention are characterized by superior high temperature resistance and are particularly useful in the preparation of high modulus molded parts using reaction injection molding (RIM) techniques.

High-modulus polyisocyanurate elastomers

Novel solid polyisocyanurate polymers are disclosed which comprises the reaction product of an organic polyisocyanate, a trimerization catalyst and a polyol combination comprising from about 0.025 to about 0.15 equivalent and about 0.05 to about 0.25 equivalent, per equivalent of polyisocyanate, respectively of an ethylene oxide capped polypropyleneoxy glycol having an equivalent weight of from about 750 to about 1500 and either 1,4-butanediol or diethylene glycol. Although containing a higher proportion of polyurethane linkages than those polyisocyanurates containing the polypropyleneoxy glycol alone, the polymers of the invention are characterized by superior high temperature resistance and are particularly useful in the preparation of high modulus molded parts using reaction injection molding (RIM) techniques.

A novel liquid isocyanate prepolymer composition is disclosed. The prepolymer is obtained by reacting a polymethylene polyphenylisocyanate containing from about 65 to about 85 percent by weight of methylenebis(phenylisocyanate) the remainder of said polymethylene polyphenylisocyanates having a functionality greater than 2, with from about 0.0185 to about 0.15 equivalent per equivalent of said polyphenylisocyanate of a polyoxyethyleneglycol having an average molecular weight of from about 200 to about 600. The liquid isocyanates so produced are characterized as storage stable liquids of relatively low viscosity which when used as the isocyanate component in polyurethane formulations, particularly molded polyurethanes, give rise to highly resilient and useful molded products.

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Branford, CT, United States of America

Peter S Carleton