Abstract: Process for preparing a polyurethane elastomer having an apparent overall density of more than 150 kg/m3 comprising reacting a polyisocyanate and an isocyanate-reactive composition, optionally in the presence of water, wherein the reaction is conducted at an isocyanate index of 85 to 120, the polyisocyanate comprising: a) 80-100% by weight of a diphenylmethane diisocyanate comprising at least 40% by weight of 4,4?-diphenylmethane diisocyanate and/or a derivative of said diphenylmethane diisocyanate which derivative is liquid at 25° C.

Abstract: Process for preparing a polyurethane material having no glass transition temperature below 25 C, which process involves using a polyoxyethylene polyoxypropylene polyol having a high oxyethylene content and a polyisocyanate having a high 4,4′-diphenylmethane diisocyanate (4,4′-MDI) content, wherein the reaction is conducted at an isocyanate index of 80 to 140.

Abstract: Process for preparing an elastomeric polyurethane material by reacting a polyisocyanate, a polyol and a monool.

Abstract: Process for preparing a polyurethane elastomer having an apparent overall density of more than 150 kg/m3 comprising reacting a polyisocyanate and an isocyanate-reactive composition, optionally in the presence of water, wherein the reaction is conducted at an isocyanate index of 85 to 120, the polyisocyanate comprising: a) 80-100% by weight of a diphenylmethane diisocyanate comprising at least 40% by weight of 4,4′-diphenylmethane diisocyanate and/or a derivative of said diphenylmethane diisocyanate which derivative is liquid at 25° C.

Abstract: Process for preparing a polyurethane material having no glass transition temperature below 25° C., which process comprises reacting a polyisocyanate and an isocyanate-reactive composition, optionally in the presence of water in an amount of less than 5% by weight on the below isocyanate-reactive composition, wherein the reaction is conducted at an isocyanate index of 80 to 140, the polyisocyanate consists of a) 80-100% by weight of diphenylmethane diisocyanate comprising at least 40%, preferably at least 60% and most preferably at least 85% by weight of 4,4′-diphenylmethane diisocyanate and/or a variant of said diphenylmethane diisocyanate which variant is liquid at 25° C.

Abstract: Process for preparing flexible polyurethane foam by reacting an MDI-based polyisocyanate and a polyether polyol with a high oxyethylene content in a mould.

Abstract: A polyisocyanate-based elastomer having a ratio of the storage modulus (E′) at 20° C. and the storage modulus (E′) at 120° C. of between 0.75 and 1.5, a tan &dgr; at 100° C. of less than 0.1 and a maximum value of the tan &dgr; of more than 0.8, the tan &dgr; being the ratio of the loss modulus (E″) and the storage modulus (E′).

Abstract: Compositions comprising (A) a rigid thermoplastic polyurethane not having a major glass transition temperature (Tg) of less than 60° C. and (B) a rubber-like material having a Tg of less than 20° C., wherein the weight ratio (A):(B) is at most 85:15.

Abstract: Process for preparing a flexible foam by reacting a prepolymer having an NCO value of 3-15% by weight, which is the reaction product obtained by reacting an excessive amount of a polyisocyanate with a polyether polyol or a mixture of such polyols, said polyol or mixture having an average nominal hydroxyl functionality of from 2 to 6, an average hydroxyl equivalent weight of from 500 to 5000 and an oxyethylene content of at least 50% by weight, with water, the amount of water being 15-500 parts by weight per 100 parts by weight of prepolymer, at the start of the reaction the temperature of the prepolymer being 10-50° C. and the temperature of the water being 10-50° C. higher than the temperature of the prepolymer and a process for preparing a flexible foam by reacting the above prepolymer with water in the presence of a superabsorbent polymer.

Abstract: A method for the production of polyurethane elastomers by reacting an isocyanate epolymer having an isocyanate content of from 5 to 10% by weight which is the reaction product of an excessive amount of a polyisocyanate containing at least 85% by weight of 4,4'-diphenylmethane diisocyanate or a variant thereof and a polyether polyol having an average nominal hydroxyl functionality of from 2 to 4, an average hydroxyl equivalent weight of from 500 to 3000, and an oxyethylene content of from 50 to 85% by weight, with an aqueous latex to form a foam, and compressing said foam.

Abstract: Hydrophilic flexible polyurethane foam which foam is in a compressed state above its glass transition temperature and at ambient pressure in the absence of force suitable to create the compressed state.

Abstract: Process for preparing a flexible foam by reacting a prepolymer having an NCO value of 3-15% by weight, which is the reaction product obtained by reacting an excessive amount of a polyisocyanate with a polyether polyol or a mixture of such polyols, said polyol or mixture having an average nominal hydroxyl functionality of from 2 to 6, an average hydroxyl equivalent weight of from 500 to 5000 and an oxyethylene content of at least 50% by weight, with water, the amount of water being 15-500 parts by weight per 100 parts by weight of prepolymer, at the start of the reaction the temperature of the prepolymer being 10.degree.-50.degree. C. and the temperature of the water being 10.degree.-50.degree. C. higher than the temperature of the prepolymer and a process for preparing a flexible foam by reacting the above prepolymer with water in the presence of a superabsorbent polymer.