Flame retardant thermoplastic molding compounds of high electroconductivity
AssigneeM.I.Tech Co., Ltd.
InventorLothar W. Kleiner
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Abstract
Flame retardant, conductive plastic molding compositions are provided in granular form comprising a thermoplastic resinous matrix through which are distributed fine, solid anisometrically shaped metallic particles in amounts totalling between about 12% and about 40% by volume. The formulation of said matrix is such that it contains at least about 24% by weight of chlorine derived primarily from vinyl chloride resins having K values between about 45 and about 70, and it also contains from about 3% to about 15% by weight of balanced lubricant/stabilizer combinations. Said anisometrically shaped metallic particles typically have aspect ratios of over about 10 to 1 and a minimum characteristic dimension of over 1 micron and are preferably composed almost entirely of conductive metal.
Claims16
A flame retardant, thermpolastic molding composition of high electroconductivity comprising between about 12% and about 40% by volume of fine solid, conductive metallic particles of anisometric shape having an aspect ratio of at least 10 to 1 and an average minimum characteristic linear dimension (thickness) of at last about 1 micron but not over about 100 microns, dispersed within a cementitious matrix having a chlorine content of at least about 24% by weight and composed predominantly of thermoplastic resins at least about half of which by weight is made up of vinyl chloride polymers which have a vinyl chloride content of at least about 80% by weight and K values between about 45 and about 70, said cementitious matrix also containing from about 3% to about 15% by weight of a well balanced lubricant/stabilizer combination including at least two different lubricants which are solid at temperatures up to at least 50.degree. C. wherein said stabilizer/lubricant combination includes at least about 1% by weight of waxy lubricant, at least about 1% by weight of fatty acid salts of magnesium, lithium and/or alkaline earth metals and at least about 1% by weight of heat stabilizer compounds of metallic elements from Group IVA or VA of the Periodic Table.
A molding composition as in claim 6 wherein said impact improving polymeric adjuvants are either copolymers formed by graft-type polymerization of one or more comonomers from vinyl aromatics, acrylate monomers and acrylonitriles in the presence of preformed rubbery backbone polymer, or chlorinated linear polyethylene containing between about 25% and about 50% of combined chlorine by weight.
A granular, flame retardant, thermoplastic molding composition of high electroconductivity comprising between about 15% and about 35% by volume of anisometric solid particles of conductive metal having an aspect ratio between about 20 to 1 and about 100 to 1 and a characteristic minimum dimension of between about 5 and about 50 microns, which particles are thoroughly dispersed in a cementitious matrix having a chlorine content of at least about 24% by weight and composed predominantly of thermoplastic resins at least about half by weight of which are made up of rigid vinyl chloride resins containing not less than about 85% by weight of vinyl chloride and having K values between about 50 and about 60, said cementitious matrix also containing from about 3% to about 15% by weight of a well balanced lubricant/stabilizer combination including at least two different lubricants which are solid at temperatures up to at least 50.degree. C. wherein said stabilizer/lubricant combination includes at least about 1% by weight of waxy lubricant, at least about 1% by weight of fatty acid salts of magnesium, lithium and/or alkaline earth metals and at least about 1% by weight of heat stabilizer compounds of metallic elements from Group IVA or VA of the Periodic Table.
Dependencies are inferred from the claim text.