US4194877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dye-containing polymer composition
Assignee: Government of the United States of America
•
Filing: 1977-11-28
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Granted: 1980-03-25
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Expires: 1997-11-28
Abstract
Abstract The preparation of dye-containing compositions, in which the dye is copolymerized with an acrylic based monomer, is disclosed. A hydrophilic copolymer is formed in which the dye is present in a nondiffusible form. The dye-acrylic polymer composition can be produced in the form of microbeads by emulsion polymerization. In addition, light scattering particles may be added in the form of a material such as polystyrene microspheres.
Inventors
- 👤 John I. Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:18
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/44; C09; C09B; C09B69/00; C09B69/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
55 words
A method for the preparation of a pH indicating dye-containing polymer composition, which comprises: subjecting acrylamide monomer to polymerization conditions in the presence of a pH indicating color changing dye material selected from the group consisting of phenol red, brillant yellow and rosolic acid to produce a hydrophilic polymer composition of acrylamide and said dye.
Claim 2
Independent Claim
55 words
A method for the preparation of a pH indicating dye-containing polymer composition, which comprises: subjecting acrylamide monomer to polymerization conditions in the presence of a pH indicating color changing dye material selected from the group consisting of phenol red, brillant yellow and rosolic acid to produce a hydrophilic polymer composition of acrylamide and said dye.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein said polymerization conditions comprise emulsion polymerization conditions and wherein said hydrophilic polymer composition is produced in the form of microbeads.
Claim 4
Dependent Claim
19 words
Method of claim 1 further including the step of adding a light scattering material to said hydrophilic polymer composition.
Claim 5
Dependent Claim
13 words
The method of claim 3, wherein said light scattering material comprises polystyrene microspheres.
Claim 6
Dependent Claim
35 words
A hydrophilic polymer composition of acrylamide monomer and a pH indicating color changing dye material selected from the group consisting of phenol red, brillant yellow and rosolic acid obtained by the method of claim 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-03-25 | 1983-09-24 | 1984-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-25 | 1987-09-24 | 1988-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-25 | 1991-09-24 | 1992-03-25 | $7700.00 | Window Closed / Lapsed |