Preparation of ultrapure N-vinylpyrrolidone polymers
    1.
    发明授权
    Preparation of ultrapure N-vinylpyrrolidone polymers 失效
    超纯N-乙烯基吡咯烷酮聚合物的制备

    公开(公告)号:US5354945A

    公开(公告)日:1994-10-11

    申请号:US982885

    申请日:1992-11-30

    CPC分类号: C08F6/003 Y10S210/908

    摘要: A process for preparing ultrapure polymers (or solutions thereof) which contain at least 20% by weight of N-vinylpyrrolidone as copolymerized units and have a Fikentscher K value of from 10 to 45 by customary free-radical polymerization in solution and subsequent purification of the solution with or without drying comprises purifying the solutions of the polymers by separating off the low molecular weight impurities by means of ultrafiltration at from 20.degree. to 100.degree. C. and from 1 to 80 bar.

    摘要翻译: 一种制备超纯聚合物(或其溶液)的方法,其含有至少20重量%的N-乙烯基吡咯烷酮作为共聚单元,并且通过溶液中的常规自由基聚合将Fikentscher K值设定为10至45,随后纯化 有或没有干燥的溶液包括通过在20℃至100℃和1至80巴下的超滤分离低分子量杂质来纯化聚合物溶液。

    Preparation of benzaldehyde dialkyl acetals
    8.
    发明授权
    Preparation of benzaldehyde dialkyl acetals 失效
    制备苯甲醛二烷基缩醛

    公开(公告)号:US5507922A

    公开(公告)日:1996-04-16

    申请号:US289277

    申请日:1994-08-11

    IPC分类号: C07C41/50 C07C43/307 C25B3/02

    CPC分类号: C25B3/02

    摘要: Benzaldehyde dialkyl acetals of the general formula I ##STR1## where R.sup.1 is C.sub.1 -C.sub.6 -alkyl, R.sup.2 is C.sub.1 -C.sub.6 -alkyl, C.sub.1 -C.sub.6 -alkoxy, halogen, cyano or carboxyalkyl where the alkyl group is of 1 to 6 carbon atoms, n is an integer of from 1 to 3 and the radicals R.sup.2 may be identical or different when n is >1, are prepared by electrochemical oxidation of a substituted toluene compound of the general formula II ##STR2## by a process in which a substituted toluene compound II is oxidized in the presence of an alkanol R.sup.1 --OH and of an auxiliary electrolyte in an electrolysis cell, the reaction solution thus obtained is let down outside the electrolysis cell to a pressure which is from 10 mbar to 10 bar lower than the pressure in the electrolysis cell andA) in the batchwise procedure, the gas released from the reaction solution on letting down the latter is separated off and the reaction solution is recycled at least once to the electrolysis cell, subjected to electrolysis, let down, separated from the released gas and then worked up to obtain the product, orB) in the continuous procedure, some of the reaction solution is worked up to obtain the product and the remaining part of the reaction solution is mixed with an amount of the originally used reaction solution which corresponds to the part removed and is recycled to the electrolysis cell, subjected to electrolysis and let down.

    摘要翻译: 其中R 1是C 1 -C 6烷基,R 2是C 1 -C 6烷基,C 1 -C 6烷氧基,卤素,氰基或羧基烷基的苯甲醛二烷基缩醛,其中烷基是1至6碳 原子,n为1〜3的整数,并且当n> 1时,基团R2可以相同或不同,是通过以下方法制备的,通过以下方法制备通式II II的取代的甲苯化合物:其中 取代的甲苯化合物II在电解槽中在烷醇R1-OH和辅助电解质的存在下被氧化,将由此获得的反应溶液在电解槽内排出至10mbar至10bar以下的压力 比电解池中的压力和A)在分批程序中,将从反应溶液中释放的气体释放出来,将反应溶液再循环至少一次至电解槽,进行电解,放电 与...分开 释放气体,然后处理以获得产物,或B)在连续步骤中,处理一些反应溶液以获得产物,并将剩余部分的反应溶液与一定量的最初使用的反应溶液 其对应于去除的部分并且被再循环到电解槽中,进行电解和放电。

    Removal of salts by electrodialysis
    9.
    发明授权
    Removal of salts by electrodialysis 失效
    通过电渗析去除盐

    公开(公告)号:US5282939A

    公开(公告)日:1994-02-01

    申请号:US783868

    申请日:1991-10-29

    申请人: Hartwig Voss

    发明人: Hartwig Voss

    IPC分类号: B01D61/44 C09B67/54

    CPC分类号: B01D61/44 C09B67/0096

    摘要: Salts of polybasic low molecular weight acids are removed from aqueous solutions containing anionic organic compounds by electrodialysis by acidifying the aqueous solution before or during salt removal.

    摘要翻译: 通过在脱盐之前或期间酸化水溶液通过电渗析从含有阴离子有机化合物的水溶液中除去多元低分子量酸的盐。