Abstract: A process for preparing a polyarylene sulfide which comprises reacting an alkali metal sulfide compound and a polyhalo-substituted aromatic compound in an organic polar solvent in the presence of(A) an alkali metal salt of a phenolic aromatic sulfonic acid of the formula:(HO).sub.m --Ar--(SO.sub.3 M).sub.nwherein Ar is a di- to tetravalent aromatic group having 6 to 24 carbon atoms; M is an alkali metal; and m and n are each 1 or 2,(B) an alkali metal hydroxide and/or an alkali metal alcoholate, and optionally,(C) an alkali metal salt of sulfuric acid.

Abstract: Herein disclosed is an auto-reverse mechanism for a tape recorder, in which a switching plate is slid by the rotations of a reverse gear adapted to intermittently rotate following the rotations of a motor so that it switches pinch rollers thereby to change the running direction of a magnetic tape. The reverse gear is formed with first and second guide portions which are defined by cam protrusions. A cam plate for imparting an initial rotation to the reverse gear and for rotations in selective engagement with the first and second guide portions is equipped with a drive member for sliding a lock plate for locking a fast forward lever or a rewinding lever so that the lock plate is slid, when the cam plate engages with the first guide portion of the reverse gear, but not when the cam plate engages with the second guide portion.