US4347104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture-insensitive electrically-conductive paper
Assignee: 3M Co
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Filing: 1979-05-18
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Granted: 1982-08-31
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Expires: 1999-05-18
Abstract
Abstract Electrically-conductive paper comprising a mixture of electrically-conductive fibers, wood pulp and synthetic wood pulp, the ratio between the two types of pulp being so selected that the electrical conductivity of the paper does not change appreciably with changes in ambient moisture. The conductive paper may be encapsulated within an electrically-insulating moisture barrier.
Inventors
- 👤 Daryl D. Dressler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:03
CPC Classifications
D; D21; D21H; D21H5/00; D21H5/12; D21H11/00; D21H13/00; H; H01; H01B; H01B1/00; H01B1/20; H01B1/24; H01B7/00; H01B7/17; H01B7/28; H01B7/282; Y; Y02; Y02A; Y02A30/00; Y02A30/14; Y10; Y10T; Y10T428/00; Y10T428/30
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
105 words
Electrically-conductive paper which has little change in electrical conductivity with changes in humidity and comprises (1) 2-50 parts by weight of wood pulp, (2) correspondingly 98-50 parts by weight of water-dispersible synthetic wood pulp (SWP), (3) electrically conductive carbonaceous fibers comprising at least 80% carbon by weight and in an amount providing 1-35% by weight of the paper, the SWP/wood pulp ratio being at least 4:1 when the paper is unencapsulated and at most 9:1 when the paper is encapsulated in an envelope which transmits less than one gram of water per 100 square inches per 24 hours at 100° F. and 95% relative humidity.
Claim 2
Dependent Claim
105 words
Electrically-conductive paper which has little change in electrical conductivity with changes in humidity and comprises (1) 2-50 parts by weight of wood pulp, (2) correspondingly 98-50 parts by weight of water-dispersible synthetic wood pulp (SWP), (3) electrically conductive carbonaceous fibers comprising at least 80% carbon by weight and in an amount providing 1-35% by weight of the paper, the SWP/wood pulp ratio being at least 4:1 when the paper is unencapsulated and at most 9:1 when the paper is encapsulated in an envelope which transmits less than one gram of water per 100 square inches per 24 hours at 100° F. and 95% relative humidity.
Claim 3
Dependent Claim
19 words
Electrically-conductive paper as defined in claim 1 which is unencapsulated and the SWP/wood pulp ratio is 12:1 to 20:1.
Claim 4
Dependent Claim
45 words
Electrically-conductive paper as defined in claim 1 which is encapsulated within a moisture barrier which transmits less than one gram of water per 100 square inches per 24 hours at 100° F. and 95% relative humidity and the SWP/wood pulp ratio is 1:1 to 9:1.
Claim 5
Dependent Claim
42 words
Electrically-conductive paper as defined in claim 3 which is encapsulated between two pieces of a laminate of biaxially-oriented polyethylene terephthalate film and polyethylene film, the polyethylene layers being fused to the paper and to each other beyond the edges of the paper.
Claim 6
Dependent Claim
20 words
Electrically-conductive paper as defined in claim 1 which is unencapsulated and the SWP/wood pulp ratio is between 4:1 and 49:1.
Claim 7
Dependent Claim
39 words
Electrically-conductive paper as defined in claim 3 wherein said moisture barrier transmits about 0.25 gram of water per 100 square inches per 24 hours at 100° F. and 95% relative humidity and the SWP/wood pulp ratio is about 70:30.
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) | 1985-08-30 | 1986-03-01 | 1986-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-30 | 1990-03-01 | 1990-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-30 | 1994-03-01 | 1994-08-31 | $7700.00 | Window Closed / Lapsed |