GB1287614A - Process for the preparation of ferromagnetic chromium dioxide - Google Patents
Process for the preparation of ferromagnetic chromium dioxideInfo
- Publication number
- GB1287614A GB1287614A GB4913769A GB4913769A GB1287614A GB 1287614 A GB1287614 A GB 1287614A GB 4913769 A GB4913769 A GB 4913769A GB 4913769 A GB4913769 A GB 4913769A GB 1287614 A GB1287614 A GB 1287614A
- Authority
- GB
- United Kingdom
- Prior art keywords
- cro
- chromium oxide
- stage
- preparation
- tellurium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70636—CrO2
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G37/00—Compounds of chromium
- C01G37/02—Oxides or hydrates thereof
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/42—Magnetic properties
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Hard Magnetic Materials (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Magnetic Record Carriers (AREA)
Abstract
1287614 Chromium oxide FARBENFABRIKEN BAYER AG 7 Oct 1969 [11 Oct 1968] 49137/69 Heading C1A [Also in Division H1] Ferromagnetic CrO 2 is made by (1) heating CrO 3 with a modifier to 200-380‹ C. to form a chromium oxide in which the chromium has an average valency of above 4 but below 6; (2) heating this chromium oxide with CrO 3 in the presence of water to 200-400‹ C. at a pressure of 1 to 500 kg./cm.<SP>2</SP>, using 1-40% wt. per cent of the chromium oxide product of (1) based on the weight of CrO 3 used in the second stage. The modifier, which may comprise 1-30 wt. per cent of the CrO 3 used in stage (1), may be tellurium or tellurium and/or antimony compounds with or without iron oxides or hydroxides. In examples, the products from stage (1) are Cr 3 O 8 or a mixture of Cr 3 O 8 and Cr 2 O 5 modified with TeO 2 , Sb 2 O 3 or α-FeOOH. The CrO 2 products may have a remanence of 400-500 Gauss cm.<SP>3</SP>g.<SP>-1</SP> and a coercivity of 200-500 Ve and consist of acicular particles 0À1-2 Á x 0À02-0À1 Á.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19681802469 DE1802469A1 (en) | 1968-10-11 | 1968-10-11 | Process for the production of ferromagnetic chromium dioxide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1287614A true GB1287614A (en) | 1972-09-06 |
Family
ID=5710250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4913769A Expired GB1287614A (en) | 1968-10-11 | 1969-10-07 | Process for the preparation of ferromagnetic chromium dioxide |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS4840799B1 (en) |
| BE (1) | BE740103A (en) |
| CH (1) | CH522567A (en) |
| DE (1) | DE1802469A1 (en) |
| FR (1) | FR2020441B1 (en) |
| GB (1) | GB1287614A (en) |
| NL (1) | NL6915398A (en) |
| SE (1) | SE365492B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1244457B (en) * | 1963-01-04 | 1967-07-13 | Ernst Zimlich | Motor-driven lawn mower with horizontally rotating blade |
| DE2022820C3 (en) * | 1970-05-11 | 1980-01-03 | Basf Ag, 6700 Ludwigshafen | Process for the production of highly coercive chromium dioxide |
| IT1045191B (en) * | 1975-10-31 | 1980-05-10 | Montedison Spa | PROCEDURE FOR THE PRODUCTION OF FERROMAGNETIC CHROMIUM DIOXIDE |
-
1968
- 1968-10-11 DE DE19681802469 patent/DE1802469A1/en active Pending
-
1969
- 1969-10-03 CH CH1492669A patent/CH522567A/en not_active IP Right Cessation
- 1969-10-07 GB GB4913769A patent/GB1287614A/en not_active Expired
- 1969-10-10 NL NL6915398A patent/NL6915398A/xx unknown
- 1969-10-10 BE BE740103D patent/BE740103A/xx unknown
- 1969-10-10 FR FR6934842A patent/FR2020441B1/fr not_active Expired
- 1969-10-10 SE SE13980/69A patent/SE365492B/xx unknown
- 1969-10-11 JP JP44081035A patent/JPS4840799B1/ja active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| BE740103A (en) | 1970-04-10 |
| JPS4840799B1 (en) | 1973-12-03 |
| DE1802469A1 (en) | 1971-10-28 |
| CH522567A (en) | 1972-06-30 |
| FR2020441A1 (en) | 1970-07-10 |
| FR2020441B1 (en) | 1973-12-07 |
| SE365492B (en) | 1974-03-25 |
| NL6915398A (en) | 1970-04-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PLNP | Patent lapsed through nonpayment of renewal fees |