Hooker Chemicals & Plastics Corporation

Occidental Chemical Corporation

Myron C Annis

Akio Takahashi

Geoffrey H Smith

Donald W Hoch

Herman J Harrington

Brian M Rushton

High shielding efficiencies to emissions of electromagnetic interference are achieved with molding compositions comprised of thermosetting resins and a multi-component electroconductive filler system. Compounds having a combination of at least two conductive fillers provide shielding efficiencies of 30 dB of attenuation or more to electromagnetic emissions over a frequency range of 0.5 to 1000 Mhz without adversely affecting mechanical properties and processing capabilities.

High performance molding compounds for shielding electromagnetic

Phenolic novolak resins are described which are structurally characterized as having from about 55% to about 90% of the available theoretical paraphenyl linkages in the resin chain bridged to a phenyl group. The resin compositions of this invention provide extended resin stability at relatively low temperatures without significant adverse affect on the cure speed at the molding temperature. The resins are especially suited for use in runnerless injection or cold manifold molding processes, but can also be used in transfer, compression and injection molding processes.

Phenolic resins with improved low temperature processing stability

Phenolic novolak resins are described which provide extended resin stability at relatively low temperatures without significant adverse affect on the cure speed at the molding temperature. The resins are especially suited for use in runnerless injection or cold manifold molding processes, but can also be used in transfer, compression and injection molding processes.

There is provided a polymer composition based upon an oxyalkylated novolac intermixed with a vinyl halide polymer. The compositions of the invention provide improved processing characteristics with reduced melt viscosity and improved physical and mechanical properties. Mixtures of (1) polyvinyl halide, oxyalkylated novolac and impact modifier, such as an acrylic polymer or (2) mixtures of oxyalkylated novolac and polyvinyl halide modified to provide improved impact strength by graft polymerization show improved compatibility of the rubbery polymer phase resulting in optimum impact strength for the composition.

Oxyalkylated novolac modifiers for polyvinyl halide compositions

Reactive mixtures comprising a polydienediol, an hydroxyalkylated novolac, and a polyisocyanate may be mixed with an inert filler composition to form granular molding compounds suitable for the preparation of molded articles having advantageous mechanical and electrical properties.

Growing community of inventors

North Tonawanda, NY, United States of America

Myron C Annis