Cast plates with a high impact resistance, their preparation process and shaped articles obtained

摘要

A mixture of methyl methacrylate, of at least one radical polymerisation initiator, of at least one organic compound containing at least two isocyanate functional groups, of at least one crosslinking agent for methyl methacrylate, of at least one polyol capable of forming a polyurethane network with the isocyanate functional groups of the organic compound and of at least one catalyst capable of permitting the formation of the said polyurethane network is introduced into a mould, the ratio of the components of the polyurethane network to the sum of these components and of the methyl methacrylate being between 5% and 35% by weight, and the mould is then subjected to pressure and temperature conditions which are such as to permit successively the formation of the polyurethane network and then the polymerisation of the methyl methacrylate in the said network. Application to the production of bulletproof sheets. IMAGE