US4410643A
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US
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Method of making and the composition for an initially erasable ink for a ball point writing instrument
Assignee: SCRIPTO-TOKAI Corp A CORP OF
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Filing: 1982-05-07
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Granted: 1983-10-18
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Expires: 2002-05-07
Abstract
Abstract A method for making and the composition for an initially erasable ink for a ball point writing instrument which ink is characterized by its initial erasability by ordinary pencil erasers when applied by a ball point writing instrument to an absorbent paper-like writing surface and which thereafter develops permanence. The method includes the steps of: (a) selecting elastomeric material from synthetic rubbers not having the chemical structure of natural rubber, with or without cis-1,4-polyisoprene, and mixtures thereof; (b) masticating the selected elastomeric material by subjecting same to high shear stresses; (c) coloring said masticated elastomeric material by forced impregnation of colored pigments into said elastomeric material while subjecting same to further shear stresses; and (d) mixing the pigmented elastomeric material with a solvent system that includes a volatile component and an essentially non-volatile low viscosity component in the form of a hydrocarbon oil, an essential oil, a petroleum derivative, a plasticizer or mixtures thereof to form an erasable ink composition. The ink composition comprises a pre-pigmented elastomer and a solvent system that contains a volatile component, a non-volatile low viscosity component, and a non-volatile component having a boiling point of 300° or greater.
Inventors
- 👤 Frank A. Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:06
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/16; C09D11/18; B; B43; B43L; B43L19/00; B43L19/0018
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
200 words
In a ball point writing instrument containing an ink capable of depositing a trace on an absorbent, paper-like writing surface having minute voids therein, said trace being characterized by initial erasability thereof by ordinary pencil erasers and developing permanence over a period of time, said ink comprising pre-pigmented elastomer dispersed in a solvent system, said pre-pigmented elastomer comprising a pigment and a solid hydrocarbon elastomer component in which the elastomer component has a Mooney viscosity within a desired range and being selected from styrene butadiene rubber, with or without polyisobutylene rubber, and the pigment is force impregnated into the elastomer component prior to the pre-pigmented elastomer being dispersed in the solvent system, said pre-pigmented elastomer and said solvent system comprising a volatile component and an essentially non-volatile component both of which are solvents for the elastomer component and in which the volatile component has a boiling point of less than 180° C. and is present in amount of 30% or less of the weight of the ink, said essentially non-volatile component having a boiling point of greater than 180° C. and being present in an amount to result in a final ink viscosity of between 0.5×10 6 -4×10 6 cps.
Claim 2
Dependent Claim
200 words
In a ball point writing instrument containing an ink capable of depositing a trace on an absorbent, paper-like writing surface having minute voids therein, said trace being characterized by initial erasability thereof by ordinary pencil erasers and developing permanence over a period of time, said ink comprising pre-pigmented elastomer dispersed in a solvent system, said pre-pigmented elastomer comprising a pigment and a solid hydrocarbon elastomer component in which the elastomer component has a Mooney viscosity within a desired range and being selected from styrene butadiene rubber, with or without polyisobutylene rubber, and the pigment is force impregnated into the elastomer component prior to the pre-pigmented elastomer being dispersed in the solvent system, said pre-pigmented elastomer and said solvent system comprising a volatile component and an essentially non-volatile component both of which are solvents for the elastomer component and in which the volatile component has a boiling point of less than 180° C. and is present in amount of 30% or less of the weight of the ink, said essentially non-volatile component having a boiling point of greater than 180° C. and being present in an amount to result in a final ink viscosity of between 0.5×10 6 -4×10 6 cps.
Claim 3
Dependent Claim
198 words
In a ball point writing instrument containing an ink capable of depositing a trace on an absorbent, paper-like writing surface having minute voids therein, said trace being characterized by initial erasability thereof by ordinary pencil erasers and developing permanence over a period of time, said ink comprising a pigment, solid hydrocarbon elastomer dispersed in a solvent system, said elastomer having a Mooney viscosity within a desired range and being selected from styrene butadiene rubber, with or without polyisobutylene rubber, said solvent system comprising a volatile component and an essentially non-volatile component both of which are solvents for the elastomer component and in which the volatile component has a boiling point of less than 180° C. and is present in amount of 30% or less of the weight of the ink, said essentially non-volatile component including a non-volatile low viscosity solvent having a boiling point at atmospheric pressure from 180° C. and less than 300° C. present in an amount of about 10-50.5% by weight of the ink, and a non-volatile high viscosity solvent or a plasticizer having a boiling point at atmospheric pressure above 300° C. being present in an amount of 23% or less of the ink.
Claim 4
Dependent Claim
198 words
In a ball point writing instrument containing an ink capable of depositing a trace on an absorbent, paper-like writing surface having minute voids therein, said trace being characterized by initial erasability thereof by ordinary pencil erasers and developing permanence over a period of time, said ink comprising a pigment, solid hydrocarbon elastomer dispersed in a solvent system, said elastomer having a Mooney viscosity within a desired range and being selected from styrene butadiene rubber, with or without polyisobutylene rubber, said solvent system comprising a volatile component and an essentially non-volatile component both of which are solvents for the elastomer component and in which the volatile component has a boiling point of less than 180° C. and is present in amount of 30% or less of the weight of the ink, said essentially non-volatile component including a non-volatile low viscosity solvent having a boiling point at atmospheric pressure from 180° C. and less than 300° C. present in an amount of about 10-50.5% by weight of the ink, and a non-volatile high viscosity solvent or a plasticizer having a boiling point at atmospheric pressure above 300° C. being present in an amount of 23% or less of the ink.
Claim 5
Dependent Claim
216 words
In a ball point writing instrument containing an ink capable of depositing a trace on an absorbent, paper-like writing surface having minute voids therein, said trace being characterized by initial erasability thereof by ordinary pencil erasers and developing permanence over a period of time, said ink comprising a pigment, solid hydrocarbon elastomer dispersed in a solvent system, said elastomer having a Mooney viscosity within a desired range and being a masticated synthetic rubber not having the chemical structure of natural rubber, and mixtures thereof, said solvent system comprising a volatile component and an essentially non-volatile component both of which are solvents for the elastomer component and in which the volatile component has a boiling point of less than 180° C. and is present in amount of 30% or less of the weight of the ink, said essentially non-volatile component including a non-volatile low viscosity solvent having a boiling point at atmospheric pressure from 180° C. and less than 300° C. present in an amount of about 10-50.5% by weight of the ink, and a non-volatile high viscosity solvent or a plasticizer having a boiling point at atmospheric pressure above 300° C. being present in an amount of 23% or less of the ink, said ink having a final viscosity of between 0.5×10 6 -4×10 6 cps.
Claim 6
Dependent Claim
216 words
In a ball point writing instrument containing an ink capable of depositing a trace on an absorbent, paper-like writing surface having minute voids therein, said trace being characterized by initial erasability thereof by ordinary pencil erasers and developing permanence over a period of time, said ink comprising a pigment, solid hydrocarbon elastomer dispersed in a solvent system, said elastomer having a Mooney viscosity within a desired range and being a masticated synthetic rubber not having the chemical structure of natural rubber, and mixtures thereof, said solvent system comprising a volatile component and an essentially non-volatile component both of which are solvents for the elastomer component and in which the volatile component has a boiling point of less than 180° C. and is present in amount of 30% or less of the weight of the ink, said essentially non-volatile component including a non-volatile low viscosity solvent having a boiling point at atmospheric pressure from 180° C. and less than 300° C. present in an amount of about 10-50.5% by weight of the ink, and a non-volatile high viscosity solvent or a plasticizer having a boiling point at atmospheric pressure above 300° C. being present in an amount of 23% or less of the ink, said ink having a final viscosity of between 0.5×10 6 -4×10 6 cps.
Claim 7
Dependent Claim
20 words
In a ball point writing instrument as defined in claim 3 wherein said masticated synthetic rubber is styrene butadiene rubber.
Claim 8
Dependent Claim
21 words
In a ball point writing instrument as defined in claim 4 wherein said masticated synthetic rubber is in admixture with polyisobutylene.
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) | 1986-10-17 | 1987-04-18 | 1987-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-17 | 1991-04-18 | 1991-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-17 | 1995-04-18 | 1995-10-18 | $7700.00 | Window Closed / Lapsed |