Abstract: This invention relates to novel allophanate-modified diphenylmethane diisocyanates, prepolymers of these allophanate-modified diphenylmethane diisocyanates, and two-component polyureas and one-component polyureaurethanes prepared from these prepolymers. In addition, the invention also relates to processes for the preparation of these various compositions, and to the preparation of sealants from the two-component polyureas and caulking agents from the one-component polyureaurethanes.

Abstract: The present invention provides a process for repairing concrete involving filling one of a void, gap or seam in the concrete with a polyurethane sealant containing a silane terminated prepolymer (“STP”), and a catalyst, optionally, one or more of plasticizers, fillers, pigments, drying agents, light stabilizers, antioxidants. thixotropic agents and bonding agents and applying an isocyanate-terminated prepolymer containing polyurethane or polyurea coating to the silane terminated prepolymer polyurethane sealant.

Abstract: The present invention provides processes for infrastructure repairs and geo-stabilization with a low-exotherm polyurethane foam, grout or elastomer. The inventive process involves at least partially filling a cavity in the infrastructure or earth with a low-exotherm polyurethane foam, grout or elastomer made from at least one polyisocyanate, at least one isocyanate-reactive compound and an organic particulate material capable of absorbing heat, optionally in the presence of one or more chosen from water, surfactants, pigments, catalysts, alkali silicates and fillers and curing the polyurethane foam, grout or elastomer. The inventive processes may improve the repair of buildings, foundations, roads, bridges, highways, sidewalks, tunnels, manholes, sewers, sewage treatment systems, water treatment systems, reservoirs, canals, irrigation ditches, etc.

Abstract: Spray polyurea elastomers and reaction systems and methods for making the same. The spray polyurea elastomers are prepared with a prepolymer formed by reacting a low 2,4′-isomer content MDI with an MDI reactive component. This prepolymer is blended with a high 2,4′-isomer content MDI to form a quasi-prepolymer. The quasi-prepolymer is reacted with an amine resin to form polyurea elastomers.

Abstract: Spray polyurea elastomers and reaction systems and methods for making the same. The spray polyurea elastomers are prepared with a prepolymer formed by reacting a low 2,4′-isomer content MDI with an MDI reactive component. This prepolymer is blended with a high 2,4′-isomer content MDI to form a quasi-prepolymer. The quasi-prepolymer is reacted with an amine resin to form polyurea elastomers.

Abstract: Prepolymer and coating compositions which moisture cure in less than about 24 hours. The prepolymers have a functionality of about 1.6 to about 2.4. Reaction systems for forming the prepolymer and coating compositions include polyol, isocyanate, and at least di-functional, aliphatic tertiary amine which has one or more EO groups on the nitrogen atom of the amine.