Rca Inc.

Thomas E Smith

Chih C Wang

Frederick Russell Nyman

An improved process for the batch distillation or purification by stripping of a bis(hydroxyalkyl)disiloxane, which purified product is useful as a video disc lubricant additive or dopant. In accordance with the process, the feedstock of bis(hydroxyalkyl)disiloxane is subjected to a vacuum evaporation of the light volatiles by gradually reducing the pressure to about 2.times.10.sup.-1 Torr. After the low boiling materials have been distilled off, the temperature is gradually increased and the pressure gradually reduced (final temperature of about 135.degree. C. and final pressure of about 4.times.10.sup.-2 Torr) so as to produce a distill and having a viscosity of about 210.+-.30 centipoise at 25.degree. C.

Purification of video disc lubricant additives

An improved apparatus and method of molding a high density information disc which includes maintaining the molding composition at an elevated temperature between the extrusion step and the record pressing step, such that the resultant disc is of improved quality. A heated shot cup is provided to maintain the extruded molding composition at the elevated temperature and in which the same is molded into a preform from which the disc is pressed.

Video disc molding process

Video disc nickel stampers are coated with a very thin, e.g., 100-250 angstroms, non-grainy layer of chromium which imparts increased scratch resistance to carbon-filled polyvinylchloride resins during compression molding.

Growing community of inventors

Indianapolis, IN, United States of America

Thomas E Smith