초록 ▼

A novel elastomer having a very low compression set and a very slow recovery from compression comprises a flexible polyurethane of essentially linear structure containing unsatisfied hydroxyl groups, and is the reaction product of substantially linear polyols having hydroxyl end groups and an averag

A novel elastomer having a very low compression set and a very slow recovery from compression comprises a flexible polyurethane of essentially linear structure containing unsatisfied hydroxyl groups, and is the reaction product of substantially linear polyols having hydroxyl end groups and an average molecular weight in the range 600 to 1200, with an aromatic isocyanate in less than stoichiometric amount. This elastomer can be used as one layer of an energy-absorbing material, in combination with a more difficultly compressible layer comprising a tough flexible polymeric matrix having a plurality of rigid hollow bodies embedded therein.

대표청구항 ▼

An elastomer comprising a flexible polyurethane of essentially linear structure containing unsatisfied hydroxyl groups, and having a compression set less than 15%, an elongation at break of at least 500%, and a recovery which is delayed after compression by at least 0.7 sec, said elastomer comprisin

An elastomer comprising a flexible polyurethane of essentially linear structure containing unsatisfied hydroxyl groups, and having a compression set less than 15%, an elongation at break of at least 500%, and a recovery which is delayed after compression by at least 0.7 sec, said elastomer comprising the reaction product of substantially linear polyols based on polyalkylene glycol and having an average molecular weight in the range of 600 to 1200, and an aromatic diisocyanate. A method of making a flexible polyurethane elastomer of essentially linear structure containing unsatisfied hydroxyl groups and having a compression set less than 15%, an elongation at break of at least 500%, and a recovery which is delayed after compression by at least 0.7 sec, which method comprises reacting substantially linear polyols based on polyalkylene glycol and having an average molecular weight in the range 600 to 1200 with an aromatic diisocyanate which is in less than stoichiometric amount.