The biodegradation Characteristic resin material for the foaming body and production manner null of the biodegradation Characteristic resin foaming body which uses

摘要

PURPOSE: To obtain a high-quality foam wherein cell walls are bonded and connected to each other to an extent as high as possible even when there are holes or gas pockets in the foam by using two biodegradable resins, one melting at higher than 100°C and the other melting at lower than 100°C, as the main components. ;CONSTITUTION: A biodegradable resin foam is produced from a compsn. contg., as the main components, a biodegradable resin melting at higher than 100°C and another biodegradable resin which melts at lower than 100°C and comprises or contains polycaprolactone. If necessary the compsn. may further contain a polyhydric alcohol and its deriv. The foam is produced as follows: granules of the biodegradable resin compsn. 10 contg. a suitable amt. of water are supplied to a hopper 11, then melted and sent with a screw 2 under heating with a heater 13, and accumu1ated at the end side of the screw 2; the screw 2 is stopped to revolve and is advanced with a piston 23 to inject the resin melt through a nozzle 12 into a mold A; and a pressure-reducing valve 41 is opened to reduce the pressure inside a pressure control room 3, causing water in the melt to evaporate instataneously, thereby to foam the melt.;COPYRIGHT: (C)1995,JPO