초록 ▼

A technique and apparatus are disclosed for injection molding highly filled conductive resin compositions. These compositions include one or more of unsaturated polyester and vinyl ester resin; a copolymer having a terminal ethylene group; and at least about 50 weight percent of an inorganic particu

A technique and apparatus are disclosed for injection molding highly filled conductive resin compositions. These compositions include one or more of unsaturated polyester and vinyl ester resin; a copolymer having a terminal ethylene group; and at least about 50 weight percent of an inorganic particulate conductive filler, an initiator, and a rheological modifier to prevent phase separation between said resin and said conductive filler during molding. The method of the present invention allows these compositions to be molded into highly intricate and thin electrically and thermally conductive specimens without significant post process machining. The method involves the use of an injection molding apparatus that has a hopper with an auger having a vertical component in its positioning to feed into the feed throat of an injection molding machine which has a phenolic screw that has been modified to have a constant inner diameter and a constant flight depth.

대표청구항 ▼

1. A process for molding a product from a composition in an injection molding apparatus having a feed throat which feeds a shot of composition into a mold, said composition comprising;a) an unsaturated prepolymer resin which comprises one or more of unsaturated polyester and vinyl ester resin; b) an

1. A process for molding a product from a composition in an injection molding apparatus having a feed throat which feeds a shot of composition into a mold, said composition comprising;a) an unsaturated prepolymer resin which comprises one or more of unsaturated polyester and vinyl ester resin; b) an unsaturated material copolymerizable with said resin and including a terminal ethylene group; c) an inorganic particulate conductive filler in an amount sufficient to provide a bulk conductivity of at least 40 S/cm to the resulting product; and d) an initiator to initiate said copolymerization; and wherein the composition is ported directly into the feed throat by an auger which has a vertical component to its positioning relative to the plane of the injection molding apparatus, and said shot is fed into the mold by a phenolic screw within the feed throat.