US4379867A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Writing medium for ball point writing instrument
Assignee: Individual
•
Filing: 1981-08-06
•
Granted: 1983-04-12
•
Expires: 2001-08-06
Abstract
Abstract A writing medium capable of being erased by merely mechanically rubbing with an ordinary pencil eraser after writing and capable of forming a drawing line possessing high adhering strength onto the surface of paper even immediately after writing on the paper. The writing medium contains a pigment as a colorant, a polynorbornane and/or trans-1,4-polyisoprene, and a mixture solvent solution for dissolving the polynorbornane and the trans-1,4-polyisoprene and containing a low boiling point organic solvent having a boiling point of less than 180° C. and a high vaporization rate and operating as a plasticizer for the polynorbornane and the trans-1,4-polyisoprene and a high boiling point organic solvent having a boiling point of higher than 300° C. and a low vaporization rate. Thus, a drawing line written with the writing medium can be erased merely by rubbing with the eraser within several hours after writing, and is not erased thereafter.
Inventors
- 👤 Tsunoda Noriaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:56
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/16; C09D11/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
70 words
A writing medium for a ball point writing instrument comprising: a pigment at least as a colorant, a polynorbornane represented by the following formula in a repetition unit, and ##STR3## a solvent solution for dissolving said polynorbornane and containing a low boiling point organic solvent having a boiling point of less than 180° C. and a high boiling point organic solvent having a boiling point of higher than 300° C.
Claim 2
Dependent Claim
70 words
A writing medium for a ball point writing instrument comprising: a pigment at least as a colorant, a polynorbornane represented by the following formula in a repetition unit, and ##STR3## a solvent solution for dissolving said polynorbornane and containing a low boiling point organic solvent having a boiling point of less than 180° C. and a high boiling point organic solvent having a boiling point of higher than 300° C.
Claim 3
Dependent Claim
73 words
The writing medium according to claim 1 wherein the amount of said polynorbornane ranges from 15 wt part to 45 wt part, the amount of said pigment ranges from 12 wt parts to 30 wt parts, the amount of said low boiling point organic solvent ranges from 10 wt parts to 50 wt parts, and the amount of said high boiling point organic solvent ranges from 15 wt parts to 35 wt parts.
Claim 4
Dependent Claim
25 words
The writing medium according to claim 1 wherein said low boiling point organic solvent is selected from the group consisting of xylene, heptane and hexane.
Claim 5
Dependent Claim
29 words
The writing medium according to claim 1 wherein said high boiling point organic solvent is selected from the group consisting of naphthene base oil, dioctyl phthalate and dioctyl adipate.
Claim 6
Dependent Claim
11 words
The writing medium according to claim 1 further comprising a lubricant.
Claim 7
Dependent Claim
24 words
The writing medium according to claim 5 wherein said lubricant is selected from the group consisting of oleic acid, lauric acid, and stearic acid.
Claim 8
Dependent Claim
89 words
A writing medium for a ball point writing instrument comprising: a pigment at least as a colorant, a mixture containing a polynorbornane represented by the following formula in a repetition unit and ##STR4## a trans-1,4-polyisoprene represented by the following formula in a repetition unit, and ##STR5## a solvent solution for dissolving said polynorborane and said trans-1,4-polyisoprene and containing a low boiling point organic solvent having a boiling point of less than 180° C. and a high boiling point organic solvent having a boiling point of higher than 300° C.
Claim 9
Dependent Claim
89 words
A writing medium for a ball point writing instrument comprising: a pigment at least as a colorant, a mixture containing a polynorbornane represented by the following formula in a repetition unit and ##STR4## a trans-1,4-polyisoprene represented by the following formula in a repetition unit, and ##STR5## a solvent solution for dissolving said polynorborane and said trans-1,4-polyisoprene and containing a low boiling point organic solvent having a boiling point of less than 180° C. and a high boiling point organic solvent having a boiling point of higher than 300° C.
Claim 10
Dependent Claim
73 words
The writing medium according to claim 7 wherein the amount of said mixture ranges from 15 wt parts to 45 wt parts, the amount of said pigment ranges from 12 wt parts to 30 wt parts, the amount of said low boiling point organic solvent ranges from 10 wt parts to 50 wt parts and the amount of said high boil point organic solvent ranges from 15 wt parts to 35 wt parts.
Claim 11
Dependent Claim
25 words
The writing medium according to claim 7 wherein said low boiling point organic solvent is selected from the group consisting of xylene, heptane and hexane.
Claim 12
Dependent Claim
29 words
The writing medium according to claim 7 wherein said high boiling point organic solvent is selected from the group consisting of naphthene base oil, dioctyl phthalate and dioctyl adipate.
Claim 13
Dependent Claim
11 words
The writing medium according to claim 7 further comprising a lubricant.
Claim 14
Dependent Claim
24 words
The writing medium according to claim 11 wherein said lubricant is selected from the group consisting of oleic acid, lauric acid, and stearic acid.
References Cited (Backward Citations)
US2721189A
Cited
US2985611A
Cited
US3083190A
Cited
US3234157A
Cited
US3299017A
Cited
US3320222A
Cited
US3330815A
Cited
US3449298A
Cited
US3557062A
Cited
US3645959A
Cited
US3715342A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |