Preparation of video disc molding composition
AssigneeRCA Corporation
InventorPaulo Sickert
Life of this patent
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Abstract
An improvement in preparing PVC resin based conductive molding compositions suitable for the manufacture of capacitive high density information discs wherein isopropyl alcohol is added to ingredients to be dry blended thus substantially reducing the amount of powder which accumulates on the inner surface of the mixing vessel during blending.
Claims3
In a process for preparing a conductive vinyl chloride resin based molding composition containing at least about 12 percent by weight of conductive carbon black particles wherein certain components of said composition, including said resin and carbon black, are mixed in the dry state in a mixing vessel, said mixing having the tendency to deposit powder onto the inner surface of said vessel, the improvement comprising adding to said dry components an amount of isopropyl alcohol sufficient to substantially reduce the amount of powder deposited on said surface during mixing, but not exceeding about 2 percent by weight of said composition.
Dependencies are inferred from the claim text.