US3743846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastic radiation indicator of the color change type
Assignee: Toshiba Corp
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Filing: 1971-02-08
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Granted: 1973-07-03
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Expires: 1991-02-08
Abstract
Abstract A plastic radiation indicator consisting of a chlorinecontaining polymer and an acid-sensitive dye which changes colors in the solid state according to the variation of pH in the acid region. The chlorine-containing polymer releases hydrogen chloride due to excitation by the radiation irradiated to the polymer, the hydrogen chloride thus released changes the color of the dye present. Since the changes of color correspond to the irradited doses, the radiation indicator can be used in dosimetry.
Inventors
- 👤 S Matsumoto
- 👤 H Fukaya
- 👤 T Tsukada
- 👤 K Umetsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:49
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/02; G01T1/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
24 words
A molded plastic radiation indicator according to claim 1, wherein the chlorine-containing polymer is a hydrocarbon polymer, chlorinated after polymerization of the monomeric hydrocarbon.
Claim 2
Dependent Claim
49 words
A molded plastic radiation indicator according to claim 1, wherein said acid sensitive dye is a compound selected from the group consisting of p-dimethylamino-azobenzene, p-diethylamino-azobenzene, 4''-dimethylamino- azobenzene-2-carboxylic acid, phenyl-azo-diphenylamine, diphenyl-diazo-bizo-bis-1-naphthylamine-4-sodium sulfonate, thymol-sulfophthalein, 3.3'', 5.5''-tetrabromo-m-cresol-sulfophthalein, mixtures of aniline blue and p-dimethylamino-azobenzene, mixtures of p-dimethylamino-azobenzene-4-sodium sulfonate and sulfonated triphenyl methane derivatives.
Claim 3
Dependent Claim
126 words
In a molded plastic radiation indicator treated with a uniform thermal hysteresis comprising a mixture which essentially consists of a polymer containing chlorine and an acid sensitive dye uniformly dispersed in the polymer at the rate of less than 3 percent by weight based on the polymer, said dye giving a color change according to variations in pH in the acid region, the improvement therein wherein the mixture additionally contains at least one of metal salts of the group consisting of stearate, maleate, laurate, sulfate, and carbonate salts, said metal being selected from the group consisting of lithium, sodium, magnesium, calcium, strontium, barium, zinc, cadmium, tim, and lead, in order to transfer a range of dosage measurable by the radiation indicator to a higher dosage region.
Claim 4
Dependent Claim
116 words
In a molded plastic radiation indicator treated with a uniform thermal hysteresis comprising a mixture which essentially consists of a polymer containing chlorine and an acid sensitive dye uniformly dispersed in the polymer at the rate of less than 3 percent by weight based on the polymer, said dye giving a color change according to variations in pH in the acid region, the improvement therein wherein the mixture additionally contains additives selected from the group consisting of alkylamines, phenylamines, diphenylamine, morpholine, quarternary ammonium slats, alkali salts of phenol, metal chlorides, metal oxides, and hydroxides of alkaline earth metals, in order to transfer a range of dosage measurable by the radiation indicator to a lower dosage region.
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |