High density information disc
AssigneeRCA Corporation
InventorsChih C. Wang, Ronald F. Bates
Life of this patent
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Abstract
High density information discs comprising conductive carbon loaded polyvinylchloride discs are lubricated with a fractionated methyl alkyl siloxane lubricant which contains an alkylene oxide silicone copolymer additive.
Claims5
In a high density information record 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 record and said stylus, said record comprising a disc of a conductive material containing an information track constituted by a surface relief pattern in said track to accommodate recovery of signals of said bandwidth upon establishment of relative motion at said rate, said record coated with a methyl alkyl siloxane lubricant having the formula ##STR5## wherein R.sub.1 and R.sub.2 are alkyl groups of 4-20 carbon atoms, x is an integer of 2-4, y is an integer of 0-2 and wherein the sum of x plus y is 4 or less, the improvement which comprises including in said lubricant an alkylene oxide silicone copolymer of the formula ##STR6## wherein R.sub.3 and R.sub.4 are lower alkyl, a is an integer of 1-2, b is an integer of 0-2 and c is an integer of 1-6.
Dependencies are inferred from the claim text.