METHOD FOR MANUFACTURING A BLOCK FROM POLYURETHANE/POLYISOCYANURATE FOAM PLATE FOR THERMAL INSULATION OF A TANK Russian patent published in 2023 - IPC C08G18/42 C08G18/76 C08J5/08 C08J9/08 C08L75/06 B63B35/00 

FIELD: chemical industry.

SUBSTANCE: invention relates to a method for producing reinforced polyurethane foam products, in particular a block of fibre-reinforced polyurethane/polyisocyanurate foam for boards used in thermal insulation tanks. The density of such blocks is less than 50 kg⋅m^-3 with a C_f fibre content of at least 4% by weight of the fibre-reinforced foam block. The process of obtaining a block includes: mixing the components necessary to obtain a polyurethane/polyisocyanurate foam; impregnation of the fibre with the resulting mixture under the action of a gravitational flow, expansion of the foam, which is limited by the walls of the two-belt laminator. Moreover, the mentioned fibres have a length of at least five centimetres and are located in layers superimposed on each other. The mixture of chemical components has a dynamic viscosity during the impregnation step, so that the impregnation time t_i of the fibres is less than the creaming time t_c of the polyurethane/polyisocyanurate foam.

EFFECT: method described makes it possible to obtain fibre-reinforced low density polyurethane and/or polyisocyanurate foam blocks having good mechanical properties.

21 cl, 4 dwg, 4 tbl, 1 ex