公开(公告)号：US3279945A

公开(公告)日：1966-10-18

申请号：US29133063

申请日：1963-06-28

Applicant: IBM

Inventor： HAINES ROBERT S ,  WALSH THOMAS J

IPC: G11C11/02 ,  H01F1/34 ,  H01F17/04

CPC classification number: H01F17/04

公开(公告)号：US3240932A

公开(公告)日：1966-03-15

申请号：US23440962

申请日：1962-10-31

Applicant: IBM

Inventor： HAINES ROBERT S

IPC: B41M5/124 ,  B41M5/36

CPC classification number: B41M5/363 ,  B41M5/124

公开(公告)号：US3200386A

公开(公告)日：1965-08-10

申请号：US8032061

申请日：1961-01-03

Applicant: IBM

Inventor： HAINES ROBERT S ,  WENNER JOHN W

IPC: G11B5/00 ,  G11B5/02 ,  G11B5/84 ,  G11B20/20

CPC classification number: G11B5/84 ,  G11B5/00 ,  G11B5/02 ,  G11B20/20

公开(公告)号：US2989415A

公开(公告)日：1961-06-20

申请号：US70375157

申请日：1957-12-19

Applicant: IBM

Inventor： HORTON PAUL V ,  HAINES ROBERT S

IPC: G11B5/702

CPC classification number: G11B5/702 ,  Y10S428/90 ,  Y10T428/31681 ,  Y10T428/31797

公开(公告)号：CA901279A

公开(公告)日：1972-05-30

申请号：CA901279D

Applicant: IBM

Inventor： HAINES ROBERT S

IPC: C01G37/02 ,  G11B5/706

公开(公告)号：CA770071A

公开(公告)日：1967-10-24

申请号：CA770071D

Applicant: IBM

Inventor： HAINES ROBERT S

公开(公告)号：CA1094779A

公开(公告)日：1981-02-03

申请号：CA267314

申请日：1976-12-07

Applicant: IBM

Inventor： HAINES ROBERT S

IPC: C01G37/027 ,  C01G37/02 ,  G11B5/706 ,  H01F1/11 ,  H01F10/02

Abstract: PROCESS FOR TREATING CHROMIUM DIOXIDE Ferromagnetic chromium dioxide is normally produced using other chromium compounds as starting materials. In most reactions a Cr(VI) compound, such as chromium trioxide is used in some stage of the procedure. Following the conversion reaction there are inevitably small amounts of the original chromium (VI) ions in the form of salts or oxide compounds which are strongly adsorbed on or attached to the chromium dioxide in a manner which prevents them from being easily removed by normal washing techniques. These Cr(VI) ions, if left in the chromium dioxide can cause problems. These disadvantages have now been overcome by treating the impure chromium dioxide with a peroxide compound in a manner which causes the Cr(VI) ions to change their character and allow their removal from the chromium dioxide.

公开(公告)号：CA915414A

公开(公告)日：1972-11-28

申请号：CA915414D

Applicant: IBM

Inventor： HAINES ROBERT S

IPC: G11B5/706 ,  H01F1/06

公开(公告)号：CA763388A

公开(公告)日：1967-07-18

申请号：CA763388D

Applicant: IBM

Inventor： HAINES ROBERT S ,  WALSH THOMAS J

公开(公告)号：CA990062A

公开(公告)日：1976-06-01

申请号：CA159873

申请日：1972-12-11

Applicant: IBM

Inventor： HAINES ROBERT S

IPC: C01G37/027 ,  C01G37/02 ,  G11B5/706 ,  H01F1/03 ,  H01F1/10 ,  H01F1/11 ,  H01F1/34

Abstract: 1409090 Ferromagnetic chromium oxide INTERNATIONAL BUSINESS MACHINES CORP 29 Nov 1972 [27 Dec 1971] 55079/72 Addition to 1317216 Heading C1A Ferromagnetic chromium oxide composition of tetragonal crystal structure containing from 58À5 to 62% by weight of chromium oxygen and from 0À05 to 0À9% by weight of carbon is prepared by forming an intimate modifying mixture of a chromium salt (e.g. chromium halide, sulphate, nitrate or acetate) and a source of elemental carbon (e.g. acetylene black, bone black, carbon black, charcoal, graphite, lamp black or carbon oxide) mixing the modifying mixture thus formed with chromium trioxide and then heating the resultant reaction mixture at a temperature within the range from 450‹ to 850‹ F. under a pressure within the range 730 p.s.i. to 44,000 p.s.i. Iron and tin may be included in the composition in amounts of 0À15 to 1À6% and 0À01 to 0À35% by weight respectively. The composition may be in the form of particles of 1 micron average length which may be mixed with organic binders and applied to suitable substrates in the preparation of magnetic recording media.