Abstract: A structure for preventing the dislocation of a spring is provided in an optical disk cartridge wherein a shutter (23) is opened and closed in accordance with a sliding movement of a sliding jig (24) provided in the inner portion of the shutter and joined to the spring contacting portions of cartridge case via a spring (27). The spring contacting portions of the cases consist of the surfaces of a contacting wall (32), and upper (33) and lower (34) walls extending from the contacting wall, the lower wall being provided with a spring dislocation preventing projection (36).

Abstract: A book case type optical disk storage container adapted to house a cartridge type optical disk with its shutter opened, the container being characterized in that one storage surface of the container is provided with a shutter stopper for keeping the shutter open, and a projection for supporting an optical disk base rotatably, the other storage surface being provided with a disk rotating jig and a disk base cleaning device. A structure for preventing the dislocation of a spring is provided in the optical disk cartridge wherein a shutter is opened and closed in accordance with a sliding movement of a sliding jig provided in the inner portion of the shutter and joined to the spring contacting portions of cartridge case via a spring. The spring contacting portions of the cases consist of the surfaces of a contacting wall, and upper and lower walls extending from the contacting wall, the lower wall being provided with a spring dislocation preventing projection.

Abstract: A process for producing sorbic acid is described, by first reacting crotonaldehyde with ketene to prepare a polyester, then decomposing the polyester with hydrochloric acid, separating the crude sorbic acid from the reaction solution, and purifying the separated sorbic acid, said purifying step comprising the following steps:(a) continuously dissolving the crude sorbic acid in petroleum at a temperature in the range of from 100.degree. to 140.degree. C. while evaporating the residual water and hydrochloric acid from the solution of the sorbic acid in petroleum;(b) separating the tar content from the petroleum solution in a separation column at a temperature in the range of from 100.degree. to 140.degree. C.; and(c) subjecting the mixture of sorbic acid and petroleum to flash evaporation in a film-type evaporator at a reduced pressure in the range of from 20 to 60 mmHg, with the evaporation residue being withdrawn from the bottom of the evaporator and recycled to step (a).