Abstract: Select NCO-terminated, uretdione group-containing polyurethane prepolymers are prepared by reacting a uretdione group-containing organic polyisocyanate with an isocyanate reactive hydrogen atom-containing compound, employing a select equivalent ratio of NCO to OH ranging from about 1.5/1 to about 2/1. The polyurethane prepolymers are useful in the preparation of lignocellulosic composite materials, such as particle board, and in making coatings.

Abstract: Uretdione group-containing polyurethane oligomers are prepared by reacting a hydroxyl-terminated prepolymer with a dicarboxylic acid anhydride. The hydroxyl-terminated prepolymer is the reaction product of a uretdione group-containing organic polyisocyanate with an isocyanate reactive hydrogen atom-containing compound. The polyurethane oligomers are useful in the preparation of aqueous polyurethane dispersions, which can be used as adhesives in making molded wood products, and as coatings and other useful products.

Abstract: Isocyanate-reactive compounds are prepared by the reaction of TDI distillation residue with a polyol in such proportions as to obtain a reaction product having an OH-number (mg KOH/g) of about 200 to about 700. The TDI distillation residue is obtained from the distillation of the product of phosgenating toluene diamine to the corresponding toluene diisocyanate and has a toluene diisocyanate content of about 30% to about 70% by weight. The isocyanate-reactive compounds are useful in polyurethane formulations.

Abstract: Isocyanate-reactive compounds are prepared by the reaction of a modified TDI distillation residue intermediate with a polyol. The modified TDI distillation residue intermediate is the reaction product of TDI distillation residue with a monohydroxylic compound. The isocyanate-reactive compounds are useful in polyurethane formulations.

Abstract: Unreacted diisocyanate is removed from a polyurethane prepolymer reaction product mixture by co-distillation of the unreacted diisocyanate with a compound which is at least partially miscible with the prepolymer and which boils at a temperature greater than the boiling point of the diisocyanate. A highly efficient removal rate is achieved in that the concentration of unreacted diisocyanate remaining in the reaction product mixture is generally less than about 0.1 percent, and in many cases less than about 0.05 percent, based on the weight of the prepolymer.

Abstract: A process for preparing select symmetrical, aromatic carbodiimides by reacting select symmetrical, aromatic ureas with phosgene in an inert liquid reaction medium. The aromatic carbodiimides produced are useful as components in the preparation of cellular and noncellular polyurethanes, and they can also be used as components in the preparation of isocyanate compositions.

Abstract: Selected tetrafunctional methylene-bridged aromatic isocyanates and a method for their preparation are disclosed. The utility of these isocyanates as cross-linking agents for polyurethanes is also disclosed.

Abstract: Selected chlorine-containing methylene-bridged diaryl diisocyanates are used in the production of polyurethane foam.

Abstract: Alkyl substituted benzene is used as a solvent to extract organic isocyanates from crude reaction mixtures containing organic isocyanates. The crude reaction mixture is admixed with the alkyl substituted benzene solvent and heated to a temperature in the range from 130.degree. C. to about 280.degree. C. for a solvent extraction period ranging from about 0.5 to about 24 hours. The alkyl substituents on the benzene contain between 1 and 15 carbon atoms and sufficient substituents to provide at least two carbon atoms in the substituents.

Abstract: Selected tetrafunctional methylene-bridged aromatic isocyanates and a method for their preparation are disclosed. The utility of these isocyanates as cross-linking agents for polyurethanes is also disclosed.

Abstract: A process for the production of methylene-bridged diaryl isocyanates by the reaction of .alpha.-halomethyl aromatic compounds with aromatic isocyanates in the presence of a catalyst. The catalyst comprises a metal salt of an aliphatic or cycloaliphatic organic acid where the metal is zinc, cadmium or mercury.Methylene-bridged diaryl isocyanates are suitably used in the production of polyurethane elastomers and foams.