Mixture capable of being converted into polyurethane foam, process for manufacture of a polyurethane foam article from such a mixture and use of the mixture in control devices

摘要

This mixture is obtained by mixing at least one first constituent, such as a polyisocyanate, and at least one second constituent, such as a polyol, a polyether or a polyester which are capable of reacting with each other to form a polyurethane foam with a release of gas, and by then rapidly cooling the mixture thus obtained by quenching in a liquid at low temperature, to stop the reaction between the two constituents and the release of gas. The solid mixture thus obtained can then be kept at low temperature and then employed for the manufacture of a polyurethane foam article by being introduced into a mould corresponding to the article to be manufactured and being heated to a sufficient temperature to cause the reaction to restart. This mixture can also be employed for checking the proper storage conditions of deep-frozen products.