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:
Jul. 29, 1997
Filed:
May. 06, 1996
Pine-Sci Kuo, Chupei, TW;
Shiao-Jung Chu, Hsinchu, TW;
Chu-Ching Dai, Hsinchu Hsien, TW;
Ching-Tang Lin, Hsinchu, TW;
Hsi-Yen Hsu, Taipei, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Acelon Chemicals and Fibers Corporation, Chang-Hua, TW;
Abstract
A method of making caprolactam from aminohexanoic acid or aminohexanoate ester comprising the steps of: (a) obtaining a reactor containing at least one catalyst, the catalyst being a metal oxide having acid-base-paired active sites; (b) charging a reaction feed into the reactor, the reaction feed containing a reactant, which is either amniohexanoic acid or C.sub.1 to C.sub.12 alkyl aminohexanoate ester, and a solvent; (c) reacting the reaction feed at a reaction temperature between 140.degree. and 300.degree. C. and a reaction pressure between 10 and 100 atm, to form a product stream; and (d) separating caprolactam from the product stream. The metal oxide catalyst is prepared from a process comprising the steps of: (a) dissolving at least a metal salt, which is not a metal oxide, in a solvent to form a metal salt solution, wherein: (i) the metal salt contains a metal element selected from the group consisting of silicon, titanium, tin, barium, calcium, magnesium, aluminum, and zinc; (ii) the solvent is selected from the group consisting of water, alcohol, ether, and mixtures thereof, and (iii) the metal salt is a salt which is soluble in the solvent; (b) adjusting the pH of the metal salt solution to be between 8 and 11, to thereby cause a precipitation of metal hydroxide; and (c) calcining the metal hydroxide at 300.degree. to 1,000.degree. C. to form a metal oxide.