Abstract: A substrate including a disk having a pair of opposed faces and being coined to provide a sub-micron flatness and smoothness for the disk faces. The coined disk can then be coated with a layer of storage material and used as a storage medium. Apparatus and a method for forming the coined substrate includes means for moving a plurality of disks along a predetermined path after the disks have been formed by blanking or stamping. The disks are cleaned before being coined and then stacked into containers which can be closed for transit to a point of use. The coining of the disks and the placement of the disks in containers is done under clean room conditions and the resulting coined substrates are free of flaws and defects encountered with the practice of conventional substrate forming techniques.
Abstract: A polyolefin resin composition consisting essentially of at least one homopolymer or copolymer of an aliphatic monoolefin and 0.05 to 2% by weight, based on the weight of the composition, of a dibenzylidene sorbitol derivative of the following formula ##STR1## wherein R and R' are different from each other and each represents a member selected from the class consisting of a hydrogen atom, a chlorine atom, alkyl groups having 1 to 3 carbon atoms and alkoxy groups having a C.sub.1 -C.sub.3 alkyl moiety.
Type:
Grant
Filed:
April 22, 1983
Date of Patent:
November 20, 1984
Assignees:
E.C. Chemical Ind. Co., Ltd., Itoh & Co., Ltd.