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:
Jun. 09, 1992
Filed:
Sep. 26, 1990
Toshiaki Kobayashi, Nara, JP;
New Japan Chemical Co., Ltd., Kyoto, JP;
Abstract
Disclosed is a process for preparing a diacetal compound such as a dibenzylidene sorbitol, comprising the steps of (i) condensing an aldehyde compound and a polyhydric alcohol in the presence of an acid catalyst and when required a lower alcohol in a hydrophobic organic solvent to give a reaction mixture containing a diacetal compound, (ii) neutralizing the reaction mixture, (iii) washing the mixture with water, (iv) removing the solvent from the mixture thus washed, and (v) drying the residual mass; the process being characterized in that an amine such as, for example, di(C.sub.10 -C.sub.26 alkyl or alkenyl)amine substituted on the nitrogen atom with a C.sub.1 -C.sub.4 alkyl group or with a group of the formula --C.sub.2 H.sub.4 O).sub.q H wherein q is an integer of 1 to 4, or a (C.sub.14 -C.sub.22 alkyl or alkenyl)amine sustituted on the nitrogen atom with one or two groups of the formula --C.sub.2 H.sub.4 O).sub.q H wherein q is 1 to 4, is added during the period from the formation of the reaction mixture to the completion of the drying step.