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US4509982A
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Ink composition for writing instruments
Assignee: Adger Kogyo Co Ltd
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Filing: 1983-09-28
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Granted: 1985-04-09
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Expires: 2003-09-28
Abstract
Abstract An aqueous ink composition useful as a writing ink, including a water-insoluble coloring agent, and a water-soluble polymeric material having a molecular weight of at least about 1×10 5 . Preferably, the polymeric material is a polyethylene oxide or an alginic acid derivative. Ink images drawn on paper using the ink composition may be easily erased by rubbing with a rubber eraser.
Inventors
- 👤 Zenshiro IIjima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:37
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
64 words
An ink composition comprising: 0.1 to 20 wt % of a water-insoluble coloring agent; 0.05 to 10 wt % of a water-soluble polymeric material which is a polyethylene oxide having a molecular weight of between about 1×10 5 and 5×10 6 ; 0.5 to 5 wt % of a nonionic or anionic surfactant having a polyoxyethylene group; and 50 to 90 wt % water.
Claim 2
Dependent Claim
64 words
An ink composition comprising: 0.1 to 20 wt % of a water-insoluble coloring agent; 0.05 to 10 wt % of a water-soluble polymeric material which is a polyethylene oxide having a molecular weight of between about 1×10 5 and 5×10 6 ; 0.5 to 5 wt % of a nonionic or anionic surfactant having a polyoxyethylene group; and 50 to 90 wt % water.
Claim 3
Dependent Claim
11 words
A composition as set forth in claim 1, further comprising methylcellulose.
Claim 4
Dependent Claim
35 words
A composition as set forth in claim 2, further comprising a thickening agent selected from the group consisting of glycerin, a polyalkylene glycol having a molecular weight of 200 to 300 and an alkylene glycol.
Claim 5
Dependent Claim
18 words
A composition as set forth in claim 1, wherein the coloring agent is carbon black or aniline black.
Claim 6
Dependent Claim
11 words
A writing instrument holding an ink composition according to claim 1.
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) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |