US4567019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color reversing compositions
Assignee: Graphic Controls Corp
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Filing: 1977-05-11
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Granted: 1986-01-28
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Expires: 1997-05-11
Abstract
Abstract Heat-sensitive compositions which rapidly develop color upon heating and rapidly discharge their color upon cooling, comprising an intimate mixture of a 3,3-bis (p-aminophenyl) phthalide and an organic acid. The color-producing and color-discharging cycle may be reproduced many times without noticeable change in response. The novel compositions of the invention are useful as temperature indicators, thermal display media, safety papers and validation devices.
Inventors
- 👤 William R. Lawton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:33
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/229; Y; Y10; Y10S; Y10S428/00; Y10S428/913
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
27 words
A heat-sensitive color-reversing composition comprising (a) a 3,3-bis(p-aminophenyl)phthalide selected from the group consisting of 3,3-bis(p-aminophenyl)phthalide, 3,3-bis(p-dimethylaminophenyl)-5-dimethylamino phthalide, 3,3-bis(p-dimethylaminophenyl)-5-amino phthalide, 3,3-bis(p-dimethylaminophenyl)-6-dimethylamino phthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3,3-bis(p-diethylaminophenyl)phthalide, 3,3-bis(p-di-n-propylaminophenyl)phthalide, 3,3-bis(4-dimethylamino-3-methylphenyl)phthalide, 3,3-bis(p-dimethylaminophenyl)-4,5,6,7-tetrachloro phthalide,
Claim 2
Dependent Claim
27 words
A heat-sensitive color-reversing composition comprising (a) a 3,3-bis(p-aminophenyl)phthalide selected from the group consisting of 3,3-bis(p-aminophenyl)phthalide, 3,3-bis(p-dimethylaminophenyl)-5-dimethylamino phthalide, 3,3-bis(p-dimethylaminophenyl)-5-amino phthalide, 3,3-bis(p-dimethylaminophenyl)-6-dimethylamino phthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3,3-bis(p-diethylaminophenyl)phthalide, 3,3-bis(p-di-n-propylaminophenyl)phthalide, 3,3-bis(4-dimethylamino-3-methylphenyl)phthalide, 3,3-bis(p-dimethylaminophenyl)-4,5,6,7-tetrachloro phthalide,
Claim 3
Dependent Claim
79 words
3-bis(p-diethylaminophenyl)-6-diethylamino phthalide, 3,3-bis(p-ethylaminophenyl)phthalide, 3,3-bis(p-methylaminophenyl)phthalide, 3,3-bis(p-benzylaminophenyl)phthalide, and 3,3-bis(p-chloromethylaminophenyl)phthalide; (b) an organic acid selected from the group consisting of thiosalicylic acid, 3-nitrosalicylic acid, 5-nitrosalicylic acid, 5-bromosalicylic acid, 3,5-dichlorosalicylic acid, 2,3-dihydroxybenzoic acid, 3,5-dibromosalicylic acid, 5-methylsalicylic acid, 5-methoxysalicylic acid, benzilic acid, 2,6-dihydroxybenzoic acid, 2-hydroxy-5-methoxybenzoic acid, 5-chlorosalicylic acid, 3,5-dinitrosalicylic acid, 1-hydroxy-2-naphthoic acid, diglycolic acid, and dithiodiglycolic acid; said color-reversing composition being characterized in that it develops a color contrasting visibly with its original color upon heating, and returns to its original color upon cooling.
Claim 4
Dependent Claim
79 words
3-bis(p-diethylaminophenyl)-6-diethylamino phthalide, 3,3-bis(p-ethylaminophenyl)phthalide, 3,3-bis(p-methylaminophenyl)phthalide, 3,3-bis(p-benzylaminophenyl)phthalide, and 3,3-bis(p-chloromethylaminophenyl)phthalide; (b) an organic acid selected from the group consisting of thiosalicylic acid, 3-nitrosalicylic acid, 5-nitrosalicylic acid, 5-bromosalicylic acid, 3,5-dichlorosalicylic acid, 2,3-dihydroxybenzoic acid, 3,5-dibromosalicylic acid, 5-methylsalicylic acid, 5-methoxysalicylic acid, benzilic acid, 2,6-dihydroxybenzoic acid, 2-hydroxy-5-methoxybenzoic acid, 5-chlorosalicylic acid, 3,5-dinitrosalicylic acid, 1-hydroxy-2-naphthoic acid, diglycolic acid, and dithiodiglycolic acid; said color-reversing composition being characterized in that it develops a color contrasting visibly with its original color upon heating, and returns to its original color upon cooling.
Claim 5
Dependent Claim
11 words
The heat-sensitive composition of claim 1, wherein said 3,3-bis(p-aminophenyl)phthalide is 3,3-bis(p-aminophenyl)phthalide.
Claim 6
Dependent Claim
13 words
The heat-sensitive composition of claim 1, wherein said organic acid is 5-bromosalicylic acid.
Claim 7
Dependent Claim
14 words
The heat-sensitive composition of claim 1 dispersed as a pigment in a binder solution.
Claim 8
Dependent Claim
13 words
A substrate coated with a single layer of the composition of claim 4.
Claim 9
Dependent Claim
21 words
The heat-sensitive composition of claim 1, and further comprising an activator reducing the temperature at which color is formed upon heating.
Claim 10
Dependent Claim
12 words
The composition of claim 6, wherein said activator comprises an aromatic sulfonamide.
Claim 11
Dependent Claim
20 words
The composition of claim 7, wherein said activator is selected from the group consisting of benzene sulfonamide and p-toluene sulfonamide.
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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) | 1989-01-27 | 1989-07-29 | 1990-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-27 | 1993-07-29 | 1994-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-27 | 1997-07-29 | 1998-01-28 | $7700.00 | Window Closed / Lapsed |