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    14.
    发明专利
    未知

    公开(公告)号：DE1189977B

    公开(公告)日：1965-04-01

    申请号：DES0082000

    申请日：1962-10-11

    Applicant: SNIA VISCOSA

    Inventor： NOTARBARTOLO LUIGI ,  MESSINA GIUSEPPE ,  MUENCH WERNER ,  MADERNO CESANO ,  MATTONE ROBERTO

    IPC: C07C51/265 ,  C07C51/42 ,  C07C51/46

    Abstract: In the manufacture of purified benzoic acid from raw materials obtained by the oxidation of toluene, the raw material is treated with water in more than a sufficient amount to form an azeotrope mmixture with all the unreacted toluene, and the azeotrope and some of the excess water are then distilled off, preferably at a temperature above the boiling point of the azeotrope, e.g. at 90-95 DEG C. Preferably, the amount of water added is such that an aqueous solution of benzoic acid of 3-5% concentration is obtained after the toluene-water azeotrope and excess water have been distilled off, and the benzoic acid solution is then freed from resinous impurities by decantation, which may be repeated. Finally, the benzoic acid is crystallized and centrifuged. The mother liquor from the crystallization is used to scrub the toluene-water azeotrope, and the azeotrope is then passed to a separator from which toluene is returned to the oxidation vessel and the aqueous layer is returned to the still in which the azeotropic distillation is effected. The process is particularly applicable to the products obtained by oxidizing toluene with air at a raised temperature, e.g. 145 DEG C., in the presence of an oxidation catalyst, e.g. cobalt enanthate.

    17.
    发明专利
    未知

    公开(公告)号：DE1620263A1

    公开(公告)日：1970-03-19

    申请号：DE1620263

    申请日：1965-04-15

    Applicant: SNIA VISCOSA

    Inventor： MUENCH WERNER ,  SILVESTRI GIULIANA ,  PAOLO ROSSI PIETRO

    IPC: B01J19/18 ,  B01J19/24 ,  C07D201/10

    Abstract: Forming caprolactam from a nitrosating agent and at least 1 cyclohexanoyl cpd., selected from hexahydrobenzoic acid, derivs. which hydrolyse to the acid or ketones in which a cyclohexane ring is attached to the ketone carbonyl group, in the presence of SO3 or H2SO4, consists of feeding the cyclohexanoyl cpd. into the first of many reaction zones into which is also fed the nitrosating agent in an amt. not exceeding 65% by wt. of the overall wt. fed into all the reaction zonex, allowing reaction to proceed and then passing the mixture of reacted cyclohexanoyl cpd. and unreacted cyclohexanoyl cpd. into at least 1 other reaction zone into which is passed nitrosating agent in an amount not exceeding 65% by wt. of the overall amt. fed into all the reaction zones and here allowing the reaction to proceed.

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