酸化()クロム

危険有害性情報のコード(GHS)

• 絵表示(GHS)

  

• 注意喚起語

  Warning

• 危険有害性情報

  H319：強い眼刺激

• 注意書き

  P305+P351+P338：眼に入った場合：水で数分間注意深く洗うこと。次にコ ンタクトレンズを着用していて容易に外せる場合は外す こと。その後も洗浄を続けること。

酸化()クロム 価格

酸化()クロム 化学特性,用途語,生産方法

• 化学的特性

  dark brown or black powder(s); tetr; used in magnetic tapes [KIR78]; ferromagnetic; rutile structure [MER06]

• 物理的性質

  Chromium dioxide [12018-01-8], chromium(IV)oxide, CrO2, is a ferromagnetic material with a specific saturation magnetization Ms/? of 132 A m2 kg?1 at 0 K, corresponding to the spin of two unpaired electrons per Cr4+ ion. TheMs/n value of CrO2 at room temperature is ca. 100 A m2 kg?1; CrO2 magnetic pigments reach values of 77–92 A m2 kg?1. The material crystallizes with a tetragonal rutile lattice in the form of small needles, which have the desired magnetic shape anisotropy. The morphology of the particles can be varied with several dopants, particularly antimony and tellurium. The coercive field strength can be controlled between ca. 30 and 75 kA m?1 (in addition to shape) by doping with transition metal ions, which modify the magneto-crystalline anisotropy of the material; the Fe3+ ion being industrially important.

• 使用

  Chromium dioxide is used exclusively for magnetic recording media. It may also be used in combination with cobalt-modified iron oxides in the production of magnetic recording media. The world consumption of CrO2 is decreasing continuously as compact disc and digital videodisc are taking over the audio and video market. The sole producer is DuPont.
  In the course of the development of pigments for magnetic information storage, CrO2 was the first widely used pigment material that gave a higher recording density than ã-Fe2O3. In the field of audio recording this led to the IEC II standard or “chrome position”.

• 調製方法

  The conversion of an intimate mixture of Cr(III) and Cr(VI) compounds into CrO2 under hydrothermal conditions has been developed into an industrial process in autoclaves at ca. 350 °C and 300 bar.
  Pure CrO2 slowly disproportionates in the presence of water. The CrO2 crystal surface of commercial pigments is therefore topotactically converted to â-CrOOH, which serves as a protection layer. In the absence of moisture, CrO2 is stable up to ca. 400 °C, above this temperature it decomposes to form Cr2O3 and oxygen.

酸化()クロム 上流と下流の製品情報

酸化()クロム 生産企業

Global(65)Suppliers

12018-01-8, 酸化()クロム キーワード