| 摘要 |
PURPOSE:To obtain a heat insulating box having heat insulating properties, which are stable with time, by a structure wherein the heat insulating box concerned consists of rigid urethane foam and an inner box made by forming high nitrile ABS resin composition, which is obtained by polymerizing monomer mixture of vinyl cyanide compound and aromatic vinyls, the contents of both of which are specified respectively. CONSTITUTION:An inner box 5 is made with a vacuum former by forming flat sheet obtained by melting high nitrile ABS resin composition, which has 52-58wt.% of acrylonitrile monomer as vinyl cyanate compound and 42-48wt.% of styrene monomer, with an extruder equipped with a coathanger die and processing. After the inner box 5 is fitted to an outer box 2, urethane stock, which adopts CO2 generated through the reaction of water with isocyanate as foaming agent, is poured between both the inner box 5 and the outer box 2 for filling so as to produce rigid urethane foam 4 in order to obtain a heat insulating box 6. Thus, the deterioration with time of the obtained box is small and its stable heat insulating properties can be maintained over a long period of time. |
