| 摘要 |
PURPOSE:To use a foamed body as a heat insulation board as it is by forming material in which many particles of multiporous foaming of vinylidene chloride group resin are adjoining and by fusing these particles tightly together. CONSTITUTION:Copolymer resin particles consisting of composition ratio by weight of 60/40 of vinylidene chloride of particles with diameter of 0.25mm. and methyl metaacrylate are put into an autoclave and after hermetically closed therein and vacuumed, a liquid mixture of foaming agent consisting of equivalent weights of flon 11 and flon 12 are added until a sample particle reaches underneath the liquid surface. After leaving at 70 deg.C for 4hr, and cooled down to 20 deg.C and reduced to the atmospheric pressure, the particles inside are taken out. After leaving the foaming particles in an open air, these particles are heated with steam for 34sec to foam and preliminary foaming particles of foaming ratio of 30 times are obtained. These preliminary foaming particles are molded by a steam mold and a flat foamed board is obtained. |
