Conductive molding composition and discs therefrom
AssigneeRCA Corporation
InventorPabitra Datta
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Abstract
Polyvinyl chloride base molding compositions containing conductive carbon particles which have been treated with a fatty acid chloride have reduced melt viscosities, improved processabilities, and increased electrical conductivities, as well as improved dispersion of the carbon particles in the molding compositions. High density information discs having improved playback performance can be readily molded from these compositions.
Claims18
In a high density information recording medium, adapted for use with a playback stylus to effect recovery of signals occupying a bandwidth of at least several megahertz when relative motion at a desired rate is established between said recording medium and said stylus, said recording medium comprising a disc of molded plastic material containing a sufficient amount of finely divided conductive particles so that the material has a bulk resistivity below about 500 ohm-cm at 900 MHz and having an information track constituted by a surface relief pattern in said track whereby said signals are recovered upon establishment of said motion at said rate, the improvement which comprises employing as said conductive particles carbon black particles the surfaces of which have been treated with a chloride of a long-chain fatty acid.
In a conductive molding composition comprising a polyvinylchloride polymer, a solid mercapto tin stabilizer, an acrylic processing aid, an internal lubricant and a sufficient amount of conductive particles so that the composition has a bulk resistivity below about 500 ohm-cm at 900 MHz, the improvement which comprises employing as said conductive particles carbon black particles the surfaces of which have been treated with a chloride of a long-chain fatty acid.
Dependencies are inferred from the claim text.