The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 14, 1993
Filed:
Oct. 30, 1991
Hiroshi Ichikawa, Yokohama, JP;
Akira Yokoyama, Yokohama, JP;
Takanobu Kawai, Yokohama, JP;
Hiroyuki Moriyama, Kudamatsu, JP;
Katsuo Komiya, Hikari, JP;
Yoshio Kato, Shinnanyou, JP;
Nippon Carbon Co., Ltd., Tokyo, JP;
Tosoh Corporation, Yamaguchi, JP;
Abstract
A packing material for liquid chromatography is produced by mixing 1.0 part by weight of carbon black, 0.5 to 2.5 parts by weight of one or a mixture of a synthetic resin which can be graphitized by heating and a toluene- or benzene-soluble component of pitches, and an organic solvent to obtain a mixture. The carbon black has a particle diameter of 12 to 40 nm, a specific surface area of 50 to 650 m.sup.2 /g, a DBP oil absorption amount of 50 to 150 ml/100 g. The synthetic resin is one selected from phenol resin, furan resin, furfural resin, divinylbenzene resin and urea resin. The pitches are ones selected from petroleum pitches, coal-tar pitches and liquefied coal oil. The mixture is granulated by spray granulation or emulsion granulation to obtain granules whose ratio L.sub.min /L.sub.max of a minor axis diameter L.sub.min to a major axis diameter L.sub.max is 0.90 to 1.0. The heat treatment of the granules is also made in an inert gas under pressure.