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AssigneeOtsuka Kagaku Kabushiki Kaisha
InventorsYasuhiko Ichikawa, Koji Sakane, Yozaburo Tsujikawa, Takio Tasaka
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A resin compound for a molding die, a molding die made of the resin compound, and a molding method using the molding die are disclosed. The resin compound includes thermoplastic resin, inorganic fiber reinforcing material and inorganic particle filler, has a flexural strength of 1000 kgf/cm.sub.2 or more and a modulus of elasticity in bending of 70000 kgf/cm.sup.2 or more, and allows machining. A deflection temperature under flexural load of the compound may be 180.degree. C. or more. From this compound, it is possible to provide a core, a cavity block or the like of molding dies which can be accurately finished by machining finishing with a low cost and within a short term, have durability and allows recycling. The molding dies can be applied to various molding methods, and provide accurate molded products with a low cost.
Resin compound for a molding die consisting essentially of 40-70 weight % of thermoplastic resin, 20-40 weight % of inorganic fiber reinforcing material having an average fiber diameter of 5 .mu.m or less, an aspect ratio of 3 or more and a Mohs' hardness of 6 or less, and 10-30 weight % of inorganic particle filler having an average particle diameter of 20 .mu.m or less and a Mohs' hardness of 6 or less, said resin compound having a flexural strength of 1000 kgf/cm.sup.2 or more and a modulus of elasticity in bending of 70000 kgf/cm.sup.2 or more, and said resin compound allowing machining, said inorganic fiber reinforcing material being at least one material selected from the group consisting of whiskers of potassium titanate, calcium silicate, magnesium borate, magnesium sulfate, calcium sulfate, calcium carbonate and aluminum borate, said inorganic particle filler being at least one material selected from the group consisting of talc, calcium carbonate and calcium pyrophosphate.
A molding die assembly comprising a core made of resin and a cavity block made of resin, core holding means for holding said core, cavity block holding means for holding said cavity block, temperature detecting means for detecting a temperature of at least one of said core and said cavity block, means for ejecting a cooling gas to said core and said cavity block, and a controller for controlling operation of said gas ejecting means in accordance with the temperature detected by said temperature detecting means so that the temperature detected by said temperature detecting means may satisfy a predetermined temperature condition, said core and said cavity block being formed of machinable thermoplastic resin compound consisting essentially of 40-70 weight % of thermoplastic resin, 20-40 weight % of inorganic fiber reinforcing material having an average fiber diameter of 5 .mu.m or less, an aspect ratio of 3 or more and a Mohs' hardness of 6 or less, and 10.mu.30 weight % of inorganic particle filler having an average particle diameter of 20 .mu.m or less and a Mohs' hardness of 6 or less, said resin compound having a flexural strength of 1000 kgf/cm.sup.2 or more and a modulus of elasticity in bending of 70000 kgf/cm.sup.2 or more, and said resin compound allowing machining , said inorganic fiber reinforcing material beina at least one material selected from the group consisting of whiskers of potassium titanate, calcium silicate, magnesium borate, magnesium sulfate, calcium sulfate, calcium carbonate and aluminum borate, said inorganic particle filler being at least one material selected from the group consisting of talc, calcium carbonate and calcium pyrophosphate.
A molding die assembly comprising a core made of resin and a cavity block made of resin, core holding means for holding said core, and cavity block holding means for holding said cavity block, said core and said cavity block being formed of machinable thermoplastic resin compound consisting essentially of 40-70 weight % of thermoplastic resin, 20-40 weight % of inorganic fiber reinforcing material having an average fiber diameter of 5 .mu.m or less, an aspect ratio of 3 or more and a Mohs' hardness of 6 or less, and 10-30 weight % of inorganic particle filler having an average particle diameter of 20 .mu.m or less and a Mohs' hardness of 6 or less, said resin compound having a flexural strength of 1000 kgf/cm.sup.2 or more and a modulus of elasticity in bending of 70000 kgf/cm.sup.2 or more, and said resin compound allowing machining, said inorganic fiber reinforcing material being at least one material selected from the group consisting of whiskers of potassium titanate, calcium silicate, magnesium borate, magnesium sulfate, calcium sulfate, calcium carbonate and aluminum borate, said inorganic particle filler being at least one material selected from the group consisting of talc, calcium carbonate and calcium pyrophosphate.
Dependencies are inferred from the claim text.