PRODUCTION OF DIPHENYLAMINE COMPOUND

• Main Authors: TAKAHATA KAZUNORI, YAMAUCHI SOUKICHI, HAYASHI HIROO
• Format: Patent
• Language: English
• Published: 22.03.1985
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; GENERAL METHODS OF ORGANIC CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING

PURPOSE:To produce the titled compound, in high yield, under a low temperature condition, with elongated catalyst life, by the vapor-phase catalytic reaction of an aniline compound using a weak acid-type silica-alumina solid acid catalyst composed mainly of gamma-alumina and containing large-sized pores at high ratio. CONSTITUTION:The objective compound is produced by using a silica-alumina solid acid catalyst composed mainly of gamma-alumina, exhibiting weak acidity represented by a Hammett's acidity function HO, max (showing the maximum acid strength of a catalyst) of >4.0, having an average pore diameter of 40-100Angstrom , the total volume of the <=100Angstrom phi pores of <=50% (especially <=30%) of the whole pore volume, and having a specific surface area of >=150m /g, and contacting the catalyst with the vapor of an aniline compound at 300-400 deg.C, preferably 330- 390 deg.C and 1-25atm for 300-1,000sec. The catalyst has high activity at a low temperature, and long life, and keeps the initial productivity comparable to the conventional catalyst even at a temperature lower than that of the conventional process by 100 deg.C.