Patent US4136229A successfully refreshed from Google Patents.
US4136229A
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Security paper
Assignee: ArjoWiggins SAS
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Filing: 1977-10-25
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Granted: 1979-01-23
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Expires: 1997-10-25
Abstract
Abstract Security paper which immediately reveals an attempt to alter handwriting thereon by the use of an alkaline ink remover and which is characterized by the incorporation therein of a pyrenesulphonic acid or a metal salt thereof, particularly an alkali metal or alkaline earth metal salt. Security paper incorporating such an acid or salt exhibits a fluorescent coloration when contacted with an alkaline ink remover.
Inventors
- 👤 Jean-Yves Godet
- 👤 Giampaolo Bartoli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:24
CPC Classifications
B; B41; B41M; B41M3/00; B41M3/14; B41M3/142; B41M3/144; B42; B42D; B42D25/00; B42D25/20; B42D25/29; C; C09; C09K; C09K11/00; C09K11/06; D; D21; D21H; D21H21/00; D21H21/14; D21H21/40; D21H21/44; D21H21/46; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S428/916
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
64 words
Security paper having incorporated therein from 0.02 to 1 g per square meter of at least one fluorescent dyestuff selected from the group consisting of a pyrenesulfonic acid and a metal salt thereof, said dyestuff not normally affecting the coloration of said paper but exhibiting a fluorescent coloration visible in daylight and in conventional lighting when said paper is contacted by an alkaline reagent.
Claim 2
Dependent Claim
64 words
Security paper having incorporated therein from 0.02 to 1 g per square meter of at least one fluorescent dyestuff selected from the group consisting of a pyrenesulfonic acid and a metal salt thereof, said dyestuff not normally affecting the coloration of said paper but exhibiting a fluorescent coloration visible in daylight and in conventional lighting when said paper is contacted by an alkaline reagent.
Claim 3
Dependent Claim
27 words
Security paper as set forth in claim 1, wherein said dyestuff is a salt selected from the group consisting of alkali metal and alkaline earth metal salts.
Claim 4
Dependent Claim
122 words
Security paper as set forth in claim 1, wherein said dyestuff is selected from the group consisting of pyrenesulfonic acids of the formula: ##STR3## wherein X 1 , X 2 , X 3 and X 4 are individually selected from the group consisting of H, SO 3 H and an electron donor group, provided that at least one of X 1 , X 2 , X 3 and X 4 is an SO 3 H group, and X 5 is selected from the group consisting of H and C 1 -C 4 alkyl groups substituted on any substitutable carbon atom of the pyrene ring system not already occupied by another substituent, and alkali metal and alkaline earth metal salts of said acids.
Claim 5
Dependent Claim
49 words
Security paper as set forth in claim 3, wherein said electron donor group is selected from the group consisting of OH and NR 1 R 2 , where R 1 and R 2 are individually selected from the group consisting of H and C 1 -C 4 alkyl groups.
Claim 6
Dependent Claim
30 words
Security paper as set forth in claim 1, wherein said dyestuff is a salt selected from the group consisting of alkali metal and alkaline earth metal salts of 3-hydroxy-pyrene-5,8,10-trisulfonic acid.
References Cited (Backward Citations)
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US3928226A
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US3886083A
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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) | 1982-01-22 | 1982-07-24 | 1983-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-22 | 1986-07-24 | 1987-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-22 | 1990-07-24 | 1991-01-23 | $7700.00 | Window Closed / Lapsed |