Manufacture of gamma-iron(III) oxide
    2.
    发明授权
    Manufacture of gamma-iron(III) oxide 失效
    制造γ-铁(III)氧化物

    公开(公告)号:US4071610A

    公开(公告)日:1978-01-31

    申请号:US677920

    申请日:1976-04-19

    摘要: A process for the manufacture of acicular gamma-iron(III) oxide, in which the non-magnetic, acicular iron(III) oxide is treated with a solution of a compound of the formula I ##STR1## where R.sup.1 and R.sup.2 are ##STR2## or O--R.sup.5, R.sup.3 is H, OH, ##STR3## or O--R.sup.5, R.sup.4 is alkyl or cycloalkyl of 1 to 16 carbon atoms and the R.sup.4 's may be identical or different, and R.sup.5 is alkyl, cycloalkyl or aralkyl of 3 to 18 carbon atoms, and is then converted to gamma-iron(III) oxide by reduction to magnetite, followed by oxidation.The gamma-iron(III) oxide obtained is distinguished by a high coercive force and improved magnetic orientation when used as a magnetic pigment for the manufacture of magnetic recording media.

    摘要翻译: 一种用于制造针状γ-铁(III)氧化物的方法,其中非磁性针状铁(III)氧化物用式I化合物(I)的溶液处理,其中R1和R2 或者O-R5,R 3是H,OH,O或R 5,R 4是1至16个碳原子的烷基或环烷基,R 4可以相同或不同,R 5是烷基,环烷基或 3至18个碳原子的芳烷基,然后通过还原成磁铁矿转化为γ-铁(III)氧化物,随后进行氧化。

    Manufacture of gamma-iron (III) oxide
    3.
    发明授权
    Manufacture of gamma-iron (III) oxide 失效
    制造γ-铁(III)氧化物

    公开(公告)号:US4018882A

    公开(公告)日:1977-04-19

    申请号:US616863

    申请日:1975-09-25

    摘要: A process for the manufacture of acicular magnetic gamma-iron(III) oxide by reducing acicular alpha-iron(III) oxide to magnetite and then oxidizing it to gamma-iron(III) oxide, wherein the alpha-iron(III) oxide is treated with a water-soluble alkaline earth metal compound and an alkylphenol with one to three alkyl radicals, each of 4 to 24 carbon atoms, on the benzene nucleus. Gamma-iron(III) oxides manufactured in this way show better magnetic orientability in the binder-containing dispersion, and a higher coercive force than prior art magnetic pigments.

    摘要翻译: 通过将针状氧化铁(III)还原成磁铁矿然后将其氧化成γ-铁(III)氧化物来制造针状磁性γ-铁(III)氧化物的方法,其中氧化铁(III)为 在苯核上用水溶性碱土金属化合物和烷基酚与一至三个碳原子数为4〜24个的烷基进行处理。 以这种方式制造的γ-氧化铁(III)氧化物在含粘合剂的分散体中显示出更好的磁定向性,并且比现有技术的磁性颜料具有更高的矫顽力。

    Isolation of pure ammonia from gas mixtures containing ammonia and
carbon dioxide
    5.
    发明授权
    Isolation of pure ammonia from gas mixtures containing ammonia and carbon dioxide 失效
    从含有氨和二氧化碳的气体混合物中分离纯氨

    公开(公告)号:US4120667A

    公开(公告)日:1978-10-17

    申请号:US841552

    申请日:1977-10-12

    IPC分类号: B01D53/14 C01C1/12

    摘要: To isolate ammonia from gas mixtures containing ammonia and carbon dioxide, the gas mixture is first partially absorbed in a solvent, with residence times of at most 0.1 second, and the non-absorbed gas is then separated from the solution obtained. The solution is then subjected to a first desorption stage, in which only the ammonia present in an excess over a molar ratio of 3 parts of ammonia to 1 part of carbon dioxide is expelled by heating, and the entrained carbon dioxide is washed out of the expelled ammonia by means of solutions containing free ammonia. The solution remaining after the first desorption stage is substantially freed from ammonia and carbon dioxide in a second desorption stage and the expelled gas, containing solvent, together with fresh gas mixture is fed to the adsorption stage, while the solvent obtained from the second desorption stage is employed for the absorption.

    摘要翻译: 为了从含有氨和二氧化碳的气体混合物中分离氨,首先将气体混合物部分地吸收在溶剂中,停留时间至多为0.1秒,然后将非吸收气体与获得的溶液分离。 然后将溶液进行第一解吸阶段,其中只有以3份氨与1份二氧化碳的摩尔比过量存在的氨通过加热排出,并将夹带的二氧化碳从 通过含有游离氨的溶液排出氨。 在第一解吸阶段后残留的溶液在第二解吸阶段基本上不含氨和二氧化碳,并且将含有溶剂的排出气体与新鲜气体混合物一起进料到吸附阶段,而从第二解吸阶段获得的溶剂 被用于吸收。

    Manufacture of gamma-iron(III) oxide
    6.
    发明授权
    Manufacture of gamma-iron(III) oxide 失效
    制造γ-铁(III)氧化物

    公开(公告)号:US4059716A

    公开(公告)日:1977-11-22

    申请号:US586346

    申请日:1975-06-12

    摘要: A process for the manufacture of acicular gamma-iron(III) oxide which, because of its improved dispersibility in organic binders, is suitable for the manufacture of magnetic recording media exhibiting a particularly high orientation ratio. For this purpose, the non-magnetic acicular .alpha.-iron(III) oxide or goethite pigment is treated with from 0.5 to 10% by weight, based on the pigment, of a compound of the formula I: ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are hydrogen, alkyl of 1 to 24 carbon atoms or alkenyl of 1 to 24 carbon atoms and (RX).sup.- is selected from the group consisting of an aliphatic carboxylic acid of 1 to 18 carbon atoms, an aromatic carboxylic acid of 1 to 18 carbon atoms, a sulfonic acid and an ester of phosphoric acid and is then further processed by conventional methods to give gamma-iron(III) oxide.

    摘要翻译: 用于制造针状γ-氧化铁(III)的方法,其由于其在有机粘合剂中的分散性的改善而适用于制造表现出特别高取向比的磁记录介质。 为此,非磁性针状α-铁(III)氧化物或针铁矿颜料以基于颜料的0.5至10重量%的式I化合物处理:其中 R 1,R 2和R 3是氢,1至24个碳原子的烷基或1至24个碳原子的链烯基和(RX) - 选自1至18个碳原子的脂族羧酸,芳族羧酸 1至18个碳原子,磺酸和磷酸酯,然后通过常规方法进一步加工,得到γ-铁(III)氧化物。