FIELD: chemistry.
SUBSTANCE: present invention relates to compositions for foaming foam plastic used in insulation materials at low temperatures. The said composition ontains 1,1,1,3,3-pentafluorobutane (HFC - 365mfc) and 1,1,1,3,3-pentafluoropropane (HFC-245fa) with mass ratio HFC-365mfc/HFC-245fa between 65:35 and 73:27.The invention also relates to a premix for producing foamed polyurethane or modified foamed polyurethane which contains such a foaming composition, at least one polyol and a catalyst for reaction of isocyanates and polyols. The invention also describes a method of producing foamed polyurethane or modified foamed polyurethane using the disclosed foaming composition, as well as heat insulation material which contains foamed polyurethane or modified foamed polyurethane made using the said method. When prepared systems are used completely, the foaming composition does not have an ignition point, which provides safe production of (modified) foamed polyurethane.
EFFECT: foam plastics made from such a foaming composition have coefficient of thermal conductivity which varies insignificantly with temperature, and exhibit better insulation properties in a wide temperature range, especially at low temperatures.
9 cl, 3 ex
