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    Process for preparing para-hydroxybenzoic acid
    1.
    发明授权
    Process for preparing para-hydroxybenzoic acid 失效
    制备对羟基苯甲酸的方法

    公开(公告)号：US5124477A

    公开(公告)日：1992-06-23

    申请号：US448333

    申请日：1989-12-11

    申请人： Toshinobu Suzuki ,  Makiko Ijiri ,  Hitoshi Saima ,  Tadahiro Wakui ,  Tokio Iizuka ,  Akinori Matsuura

    发明人： Toshinobu Suzuki ,  Makiko Ijiri ,  Hitoshi Saima ,  Tadahiro Wakui ,  Tokio Iizuka ,  Akinori Matsuura

    IPC分类号： C07C51/15

    CPC分类号： C07C51/15

    摘要： The improved process for preparing para-hydroxybenzoic acid comprises reacting potassium phenol with carbon dioxide in an inert reaction medium or without using a reaction medium in the presence of at least one compound selected from the group consisting of the compounds represented by the following general formula I or II: ##STR1## at a reaction temperature of 230.degree.-450.degree. C. and at a carbon dioxide pressure ranging from atmospheric pressure to 6 kg/cm.sup.2 (G). The process may comprise two stages and the first-stage reaction described above is followed by the second stage in which the reaction is further continued with the pressure of carbon dioxide in the system being reduced and/or the reaction temperature being elevated within the range specified above.Also, phenol may be used as the starting material instead of potassium phenolate.

    Process for preparing para-hydroxybenzoic acid
    2.
    发明授权
    Process for preparing para-hydroxybenzoic acid 失效
    制备对羟基苯甲酸的方法

    公开(公告)号：US5072036A

    公开(公告)日：1991-12-10

    申请号：US368320

    申请日：1989-06-14

    申请人： Toshinobu Suzuki ,  Makiko Ijiri ,  Tokio Iizuka ,  Hitoshi Saima ,  Tadahiro Wakui

    发明人： Toshinobu Suzuki ,  Makiko Ijiri ,  Tokio Iizuka ,  Hitoshi Saima ,  Tadahiro Wakui

    IPC分类号： C07C51/15

    CPC分类号： C07C51/15

    摘要： Para-hydroxybenzoic acid is prepared by reacting an alkali metal salt of phenol except the lithium and sodium salts with carbon dioxide in the presence of at least one compound selected from compounds of the following formulae (I) and (II): ##STR1## In formulae (I) and (II), M is an alkali metal except lithium and sodium; R is any substituent except an aliphatic hydroxy group having up to 4 carbon atoms, an aliphatic mercapto group having up to 4 carbon atoms, a substituent having at least one of them as its structural unit, and a hydrogen atom; R' is any substituent except an aliphatic hydroxy group having up to 4 carbon atoms, an aliphatic mercapto group having up to 4 carbon atoms, and a substituent having at least one of them as its structural unit; in formula (I) n is an integer of 1 to 5, and R groups may be the same or different when n is more than one; in formula (II) m is an integer of 1 to 5 and l is an integer of 0 to 4, and M alkali metals may be the same or different when m is one or more, and R' groups may be the same or different when l is more than one. The reaction may be carried out in the presence or absence of reaction medium.

    Method and apparatus for generating screened halftone images
    3.
    发明授权
    Method and apparatus for generating screened halftone images 失效
    用于产生筛选的半色调图像的方法和装置

    公开(公告)号：US4556918A

    公开(公告)日：1985-12-03

    申请号：US564235

    申请日：1983-12-21

    申请人： Taro Yamazaki ,  Masashi Okamoto ,  Tokio Iizuka ,  Norishige Tsukada ,  Kenji Okamori

    发明人： Taro Yamazaki ,  Masashi Okamoto ,  Tokio Iizuka ,  Norishige Tsukada ,  Kenji Okamori

    IPC分类号： G03F5/00 ,  H04N1/405 ,  H04N1/40

    CPC分类号： H04N1/4055

    摘要： Apparatus and method for generating screened halftone images, which includes means for assuming an area of halftone dots with desired periodicity and tone reproducibility, subdividing the area into minute cells and setting address values (X, Y) for each of the minute cells, computing out a threshold value of density for each of said cells as a function f (X, Y) of the relevant address values (X, Y), and using the computed value as threshold value of density for the cell, means for obtaining a density-related video signal of the portion of the original corresponding to each of said cells by scanning the original, and means for producing halftone dot signals by comparing the video signals and the threshold value of density with each other.

    摘要翻译： 用于生成被筛选的半色调图像的装置和方法，其包括用于假设具有期望周期性和色调再现性的半色调点区域的装置，将该区域细分为微小区并为每个微小区设置地址值（X，Y），计算出 作为所述单元的密度的阈值作为相关地址值（X，Y）的函数f（X，Y），并且使用所计算的值作为所述单元的密度的阈值， 通过扫描原稿对应于每个所述单元的原稿部分的相关视频信号，以及通过将视频信号和密度阈值相互比较来产生半色调点信号的装置。

    Solid acid catalyst of acid-treated hydrated niobium oxide and method for its preparation
    5.
    发明授权
    Solid acid catalyst of acid-treated hydrated niobium oxide and method for its preparation 失效
    酸处理水合氧化铌的固体酸催化剂及其制备方法

    公开(公告)号：US4652544A

    公开(公告)日：1987-03-24

    申请号：US767982

    申请日：1985-08-21

    申请人： Susumu Okazaki ,  Tokio Iizuka ,  Satoshi Kado

    发明人： Susumu Okazaki ,  Tokio Iizuka ,  Satoshi Kado

    IPC分类号： B01J27/195 ,  C07B61/00 ,  C07C27/00 ,  C07C29/04 ,  C07C31/08 ,  C07C67/00 ,  B01J27/14

    CPC分类号： C07C29/04 ,  B01J27/195

    摘要： A solid state catalyst consists essentially of hydrated niobium oxide containing a phosphoric acid on its surface in an amount sufficient to increase surface acidity, to inhibit crystallization of the niobium oxide and to retard loss in catalytic activity following exposure to high temperature. The catalyst can be prepared by treating hydrated niobium oxide (Nb.sub.2 O.sub.5.xH.sub.2 O) or an anhydride thereof with a phosphoric acid. The catalyst is useful in the hydration of ethylene to form ethanol.

    摘要翻译： 固态催化剂基本上由含有磷酸的水合铌氧化物组成，其表面的量足以增加表面酸度，抑制氧化铌的结晶，并延缓暴露于高温后催化活性的损失。 催化剂可以通过用磷酸处理水合氧化铌（Nb 2 O 5·xH 2 O）或其酸酐来制备。 该催化剂可用于乙烯水合形成乙醇。