US4671691A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ball-point writing instrument containing an aqueous ink composition
Assignee: Berol Corp
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Filing: 1985-01-23
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Granted: 1987-06-09
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Expires: 2005-01-23
Abstract
Abstract Gelled, aqueous inks are used in conjunction with viscoelastic ink follower compositions to avoid the necessity of using a fibrous ink reservoir or a porous or extruded ink feed rod.
Inventors
- 👤 Laura K. Case
- 👤 Chandrasen Gajria
- 👤 Rachel M. Loftin
- 👤 Henry Peper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:28
CPC Classifications
B; B43; B43K; B43K7/00; B43K7/01; B43K23/00; B43K23/08; B43K23/12; C; C09; C09D; C09D11/00; C09D11/16; C09D11/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
110 words
A ball-point pen employing a liquid ink reservoir containing an ink having a viscosity less than 100 cPs at shear rates produced by writing and comprising a combination of ingredients consisting essentially of from about 50 to about 99% by weight of a polar solvent comprising at least 50 percent by weight water, up to about 30% by weight coloring matter, and sufficient water-dispersible gum or resin to provide a shear-thinning index of from 0.01 to 0.60 said reservoir including a viscoelastic ink follower having a composition which exhibits predominately elastic response at low frequency or shear rate and a predominately viscous response at a high frequency or shear rate.
Claim 2
Dependent Claim
110 words
A ball-point pen employing a liquid ink reservoir containing an ink having a viscosity less than 100 cPs at shear rates produced by writing and comprising a combination of ingredients consisting essentially of from about 50 to about 99% by weight of a polar solvent comprising at least 50 percent by weight water, up to about 30% by weight coloring matter, and sufficient water-dispersible gum or resin to provide a shear-thinning index of from 0.01 to 0.60 said reservoir including a viscoelastic ink follower having a composition which exhibits predominately elastic response at low frequency or shear rate and a predominately viscous response at a high frequency or shear rate.
Claim 3
Dependent Claim
22 words
A ball-point pen as described in claim 1 in which the shear thinning index of said ink is from 0.05 to 0.30.
Claim 4
Dependent Claim
15 words
A ball-point pen as described in claim 1 in which said polar solvent is water.
Claim 5
Dependent Claim
31 words
A ball-point pen as described in claim 1 in which said polar solvent is a mixture of a major proportion of water and a minor proportion of a second polar solvent.
Claim 6
Dependent Claim
18 words
A ball-point pen as described in claim 1 in which said water-dispersible gum or resin is xanthan gum.
Claim 7
Dependent Claim
18 words
A ball-point pen as described in claim 2 in which said water-dispersible gum or resin is carrageenan gum.
Claim 8
Dependent Claim
49 words
A ball-point pen as described in claim 1 in which said ink follower exhibits increasing tan delta values over the shear rate range of 5 to 30,000 sec. -1 and exhibits, in addition, tan delta values of less than 1 at shear rates up to 50 sec. -1 .
Claim 9
Dependent Claim
40 words
A ball-point pen as described in claim 1 in which said viscoelastic ink follower comprises a mixture of from 5 to 99% by weight mineral oil, 5 to 99% by weight polybutene, and up to 10% by weight clay thickener.
Claim 10
Dependent Claim
25 words
A ball-point pen as described in claim 8 in which said polybutene has a number average molecular weight of from about 500 to about 5000.
Claim 11
Dependent Claim
31 words
A ball-point pen as described in claim 8 in which said clay thickener is selected from the class consisting of bentonites and montmorillonites which have been treated with an onium compound.
Claim 12
Dependent Claim
49 words
A ball-point pen as described in claim 1 in combination with a cap member adapted to sealingly contact the pen tip when the pen and cap are assembled in a closed position to prevent the passage of air or other gas between the surface of the ball and seat.
Claim 13
Dependent Claim
30 words
A ball-point pen as described in claim 1 where the water dispersible gum or resin is present in an amount from 0.10 to 5.0 percent by weight of the composition.
Claim 14
Dependent Claim
30 words
A ball-point pen as described in claim 1 where the water dispersible gum or resin is present in an amount from 0.10 to 2.0 percent by weight of the composition.
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) | 1990-06-08 | 1990-12-08 | 1991-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-08 | 1994-12-08 | 1995-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-08 | 1998-12-08 | 1999-06-09 | $7700.00 | Window Closed / Lapsed |