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公开(公告)号：US3600381A
公开(公告)日：1971-08-17
申请号：US3600381D
申请日：1969-04-21
Applicant: TEIJIN LTD
Inventor： YAMAMOTO AKIRA , YASUDA MAKOTO , FURUSAWA YUTAKA
IPC: C07D201/12 , C07D41/06
CPC classification number: C07D201/12
Abstract: A METHOD FOR THE PREPARATION OF PURE LACTAM FROM AN OLIGOMER-CONTAINING CRUDE LACTAM BY EVAPORATING SAID OLIGOMER-CONTAINING CRUDE LACTAM AT A TEMPERATURE LESS THAN THE EVAPORATION TEMPERATURE OF SAID LACTAM WHILE MAINTAINING SAID LACTAM UNDER ALKALINE CONDITIONS AND THEN RECTIFYING SAID OLIGOMER-CONTAINING CRUDE LACTAM. FURTHER PURIFICATION OF THE CRUDE LACTAM REMAINING AFTER RECTIFICATION CAN BE CARRIED OUT BY DEPOLYMERIZATION OF SAID CRUDE LACTAM IN THE PRESENCE OF AN ACIDIC CATALYST AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT 220*C. TO ABOUT 350*C. AND AT A PRESSURE WITHIN THE RANGE FROM ABOUT 0.5 TO ABOUT 6 ATMOSPHERES, SEPARATING A LACTAM AQUEOUS SOLUTION, OXIDIZING SAID LACTAM AQUEOUS SOLUTION UNTIL THE PERMANGANATE NUMBER OF THE LACTAM IS BELOW 1.50, REDUCING THE WATER CONTENT FROM SAID LACTAM AQUEOUS SOLUTION TO AT LEAST ABOUT 5%, AND RECIRULATING SAID LACTAM AQUEOUS SOLUTION TO SAID EVAPORATING STEP.
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公开(公告)号：US3669740A
公开(公告)日：1972-06-13
申请号：US3669740D
申请日：1969-10-24
Applicant: TEIJIN LTD
Inventor： YAMAMOTO AKIRA , MORIYAMA KEIICHI
CPC classification number: C08G85/008
Abstract: A METHOD OF CLEANING POLYAMIDE PRODUCING APPARATUS IS DISCLOSED, NAMELY, CONTACTING THE COATING ON THE APPARATUS, AT A TEMPERATURE ABOVE 200*C., WITH A COMPOSITION COMPRISING AT LEAST 25 WEIGHT PERCENT OF ONE OR MORE ORGANIC CARBOXYLIC ACIDS HAVING A BOILING POINT ABOVE 220*C.
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公开(公告)号：US3653964A
公开(公告)日：1972-04-04
申请号：US3653964D
申请日：1969-11-10
Applicant: TEIJIN LTD
Inventor： YAMAMOTO AKIRA , MORIYAMA KEIICHI
CPC classification number: C08G85/008
Abstract: A method of removing a coating formed on a polyamide producing apparatus by contact with a molten polyamide, which comprises contacting the coating with a composition at a temperature not lower than 200* C., said composition consisting mainly of an ethanolamine and 0.01 to 10 percent by weight, based on said ethanolamine, of a basic substance selected from the group consisting of hydroxides of alkali metals, hydroxides of alkaline earth metals and salts of alkali metals with weak acids.
Abstract translation: 一种通过与熔融聚酰胺接触除去在聚酰胺生产装置上形成的涂层的方法，该方法包括使涂层与组合物在不低于200℃的温度下接触，所述组合物主要由乙醇胺和0.01至10重量％ 基于所述乙醇胺的选自碱金属的氢氧化物，碱土金属的氢氧化物和碱金属与弱酸的盐的碱性物质。
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