Patent US3832457A successfully refreshed from Google Patents.
US3832457A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferrite contrast media with metallic oxides
Assignee: RIKEN
•
Filing: 1970-06-17
•
Granted: 1974-08-27
•
Expires: 1990-06-17
Abstract
Abstract Contrast media for radiography of organs comprises a sufficient amount of fine solid particles of at least one kind of soft magnetic ferrites suspended in a liquid carrier, wherein said carrier contains at least one kind of additive agents selected from the group consisting of organic thickening compounds such as starch, sodium alginate and polyvinyl alcohol, fine powder of metallic oxides selected from Ba, Bi, Ce, W, Zr, Sn, Ta, Vb, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Y.
Inventors
- 👤 M Sugimoto
- 👤 K Funaki
- 👤 Y Saeki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:33
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/04; A61K49/0409; A61K49/0414; A61K49/0423; A61K49/0428; B; B82; B82Y; B82Y5/00; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/34; H01F1/36; H01F1/37; H01F1/44; H01F1/445
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
144 words
at least one metal oxide selected from the group consisting of i. from about 5 to about 20%, by weight of the ferrite, of an oxide of barium, bismuth, cerium or tungsten and ii. from about 3 to about 12 percent, by weight of the ferrite, of an oxide of zirconium, tin, tantalum, yttrium, lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium or ytterbium, and b. at least one dispersion agent selected from the group consisting of starch in an amount of from 1.0 to 2.0 percent by weight, based on the total weight of said aqueous dispersion, sodium alginate in an amount of from 0.1 to 0.3 percent by weight, based on the total weight of said aqueous dispersion and polyvinyl alcohol in an amount of from 4 to 6 percent by weight, based on the total weight of said aqueous dispersion.
Claim 2
Dependent Claim
35 words
A radiographic contrast medium according to claim 1 wherein the solubility of said magnetic ferrite in acid solution has been decreased by treating the ferrite with aqueous hydrochloric acid of a pH of about 1.0.
Claim 3
Dependent Claim
34 words
A radiographic contrast medium according to claim 1 wherein the magnetic ferrite is selected from the group consisting of copper-zinc ferrite, magnesium ferrite, nickel-zinc ferrite, manganese-zinc ferrite, ferrosoferric oxide, iron-zinc ferrite, and ferric oxide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |