INJECTION FOAM MOLDED BODY AND SPEAKER DIAPHRAGM PREPARED BY USING INJECTION FOAM MOLDED BODY

摘要

PROBLEM TO BE SOLVED: To provide an injection foam molded body which is light in weight and can improve high internal loss, high rigidity and environmental resistance without resulting in cost increase and a speaker diaphragm prepd. by the injection form molded body. SOLUTION: This speaker diaphragm has a three-layer structure wherein a foamed layer 3 is covered with a skin layer 2 being an unfoamed layer by injection molding of a resin contg. a foaming agent. In this case, mean foaming ratio of the whole speaker diaphragm contg. the skin layer 2 being the unfoamed layer is in a range of 1.1-3.0 and the thickness of the skin layer is in a range of approximately 0.05-0.20 mm.