Abstract: Disclosed is a process for producing a high purity caprolactam which comprises converting cyclohexene obtained by the partial hydrogenation of benzene into cyclohexanol through hydration, converting the cyclohexanol into cyclohexanone through dehydrogenation, converting the cyclohexanone into cyclohexanone oxime through oximation and converting the cyclohexanone oxime into caprolactam through the Beckman rearrangement, characterized by comprising isolating and purifying the methylcyclopentanol from the cyclohexanol prior to use of such cyclohexanol in dehydrogenation and feeding the isolated methylcyclopentanol directly to oximation in order that the methylcyclopentanol is not fed to dehydrogenation. The process of the invention advantageously provides an economic method for producing a caprolactam with greater purity.

Abstract: Disclosed is an easy dyeable polyester fiber. Consisting of 60-95 mol % of polyethylene terephthalate and 5-40 mol % of polytrimethylene terephthalate, the polyester fiber of the present invention is prepared through copolymerization or through the ester interchange in such a way that it ranges, in melting point from 230° C. to 250° C., in birefringence from 100 to 190×10−3, and in boil-water shrinkage, from 8 to 25. Using disperse dyes, the polyester fiber can be dyed in deep shades at as low as or lower than 100° C. under atmospheric pressure. Thus, the polyester fiber of the present invention is can be used in mixture with thermal resistance-insufficient fibers such as spandex without causing yellowing therein. Also, it does not allow spots in the dyeing to appear thereon upon after-treatment, and in addition shows good fastness to washing, water, sublimation and friction.