Kureha Kagaku Kogyo Kabushiki Kaisha

Kouichi Kodama

Shoichiro Hayashi

Ken Kashiwadate

Yoshikazu Kubota

Yutaka Konai

Yoichiro Yamanobe

Masakatsu Wagu

Satoshi Usui

A pair of tubular products of polyarylene sulfide having end faces to be welded are welded to each other by heating the end faces by a hot plate in no contact with the end faces to a surface temperature which is at least the melting heat-absorption peak temperature and at most 80.degree. C. above the melting initiation temperature of the polyarylene sulfide, and abutting the end faces under a pressure of 50-1500 kPa when the end faces are at a surface temperature which is at least 10.degree. C. above the melting initiation temperature and not exceeding the melting heat-absorption peak temperature of the polyarylene sulfide. As a result, a welded tubular structure having a weld with a small inside bead but having a sufficiently large weld strength can be obtained with substantially no thermal degradation and at a good operating efficiency.

Method of welding tubular products of polyarylene sulfide and welded

Disclosed herein is a process for producing i-brassicasterol, comprising charging a mixture of i-sterols derived from a mixture of sterols including brassicasterol into a column packed with a filler obtained by chemically binding alkyl group(s) of 15 to 24 carbon atoms to silica, and subjecting said mixture of i-sterols to reversed-phase partition column-chromatography while using (i) an alcohol of one to three carbon atoms or a mixture therof, or (ii) a mixed solvent comprising more than 50% by volume of said alcohol(s) and a solvent other than said alcohol(s) as an eluent, thereby isolating and purifying i-brassicasterol.

Process for producing i-brassicasterol

This disclosure describes an inclusion compound of cyclodextrin in which at least one guest compound selected from the group of eicosapentaenoic acid, docosahexaenoic acid and alkali metal salts and alkyl esters thereof is included.

Inclusion compound of eicosapentaenoic acid or docosahexaenoic acid with

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Iwaki, Japan

Kouichi Kodama