US5048992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Writing instrument including shock resistant ink compositions
Assignee: Berol Corp
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Filing: 1990-09-13
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Granted: 1991-09-17
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Expires: 2010-09-13
Abstract
Abstract Novel, improved aqueous-based, shear-thinning, shock-resistant ink compositions and writing instruments including the ink compositions. The ink compositions comprise a substantially uniform dispersion of colorant(s), a water-dispersible polymeric shear-thinning material, and a substantially water-soluble polymeric material in a polar solvent system.
Inventors
- 👤 Rachel M. Loftin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:43
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
138 words
A ball-point pen comprising a reservoir including a shock-resistant shear-thinning ink composition consisting essentially of: a) from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b) colorant material is an amount up to about 30 percent by weight, c) an amount of a water-dispersible, polymeric shear-thinning material sufficient to provide an ink having a shear-thinning index between about 0.5 to about 0.9, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing, and d) an amount of a water-soluble, film-forming, polymeric, shock-resistant providing material effective to provide shock-resistance for the ink composition but ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning material.
Claim 2
Dependent Claim
138 words
A ball-point pen comprising a reservoir including a shock-resistant shear-thinning ink composition consisting essentially of: a) from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b) colorant material is an amount up to about 30 percent by weight, c) an amount of a water-dispersible, polymeric shear-thinning material sufficient to provide an ink having a shear-thinning index between about 0.5 to about 0.9, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing, and d) an amount of a water-soluble, film-forming, polymeric, shock-resistant providing material effective to provide shock-resistance for the ink composition but ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning material.
Claim 3
Dependent Claim
22 words
A ball-point pen of claim 1 where the viscosity at a shear rate of 30 sec -1 is 100 cPs or greater.
Claim 4
Dependent Claim
18 words
A pen of claim 1 where the ink has a shear-thinning index between about 0.6 to about 0.8.
Claim 5
Dependent Claim
33 words
A pen of claim 1 where the shear-thinning material of the ink is selected from the group consisting of xanthan gum, carageenan gum, locust bean gum, hydroxyethylcellulose, guar gum, and mixtures of these.
Claim 6
Dependent Claim
15 words
A pen of claim 1 where the shock resistant providing material is a vinylpyrrolidone polymer.
Claim 7
Dependent Claim
15 words
A pen of claim 5 where the shock resistant providing material is a polyvinylpyrrolidone polymer.
Claim 8
Dependent Claim
47 words
A pen of claim 6 where the ink composition includes from about 0.5 to about 3.0 percent by weight xanthan gum and from about 0.5 to about 3.0 percent by weight polyvinylpyrrolidone and the ratio of polyvinylpyrrolidone to xanthan gum is between about 10:1 to about 1:10.
Claim 9
Dependent Claim
24 words
A pen of claim 1 where the solvent system of the composition comprises a mixture of water and at least one other polar solvent.
Claim 10
Dependent Claim
29 words
A pen of claim 1 where the shock-resistant providing material is selected from the group consisting of a vinyl pyrrolidone polymer, a vinyl alcohol polymer or mixtures of these.
References Cited (Backward Citations)
US3526522A
Cited
US3656857A
Cited
GB2094820A
Cited
JPS58141256A
Cited
GB2131040A
Cited
US4671691A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-16 | 1995-03-18 | 1995-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-16 | 1999-03-18 | 1999-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-16 | 2003-03-18 | 2003-09-17 | $7700.00 | Window Closed / Lapsed |