US4429216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conductive element
Assignee: INTERNATIONAL ROTEX Inc A CORP OF DE
•
Filing: 1981-01-12
•
Granted: 1984-01-31
•
Expires: 2001-01-12
Abstract
Abstract An electrically conductive element comprises a support (perferably a flexible continous polymeric film) and fibrous material (preferably a spun glass fiber web) which is partially embedded in the support and partially protruding therefrom, the protruding fibrous material being part of a conductive layer comprising randomly distributed fibers having conductive material adhered thereto. The element can be prepared from a conductive composition containing conductive particles dispersed in a liquid medium (preferably an aqueous dispersion of carbon particles) by applying said composition to a substrate comprising a support and fibrous material which is partially embedded in one surface of the support and partially protruding therefrom, and then drying to evaporate the liquid medium. The elements are particularly useful as heating elements which comprise electrodes so that current can be passed through the conductive layer.
Inventors
- 👤 Alan Brigham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:32
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/145; H05B3/20; H05B3/34; H05B3/36; H05B3/38; H05B2203/00; H05B2203/011; H05B2203/013; H05B2203/017; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/23907; Y10T428/23921; Y10T428/23979; Y10T428/23986; Y10T428/23993; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24876; Y10T428/24893; Y10T428/24901; Y10T428/24909; Y10T428/26; Y10T428/266; Y10T428/269
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
69 words
An electrically conductive element which comprises (a) a support which is a flexible continuous film of polymeric material; and (b) randomly distributed fibers having first portions which protrude from the support and which have solid particulate electrically conductive material deposited thereon and adherent thereto, thus forming an electrically conductive layer, and second portions which are embedded in the support and are substantially free of electrically conductive material adherent thereto.
Claim 2
Dependent Claim
69 words
An electrically conductive element which comprises (a) a support which is a flexible continuous film of polymeric material; and (b) randomly distributed fibers having first portions which protrude from the support and which have solid particulate electrically conductive material deposited thereon and adherent thereto, thus forming an electrically conductive layer, and second portions which are embedded in the support and are substantially free of electrically conductive material adherent thereto.
Claim 3
Dependent Claim
50 words
An element according to claim 1 wherein the support is a laminate comprising a first continuous layer of a polymeric film-forming composition and a second layer of a second polymeric composition having a lower softening point than the first polymeric composition, the fibers being partially embedded in the second layer.
Claim 4
Dependent Claim
22 words
An element according to claim 2 wherein the first polymeric composition comprises a polyester and the second polymeric composition comprises a polyolefin.
Claim 5
Dependent Claim
15 words
An element according to claim 2 wherein the second layer is a hot melt adhesive.
Claim 6
Dependent Claim
36 words
An element according to claim 1 wherein the support is a laminate comprising a first continuous layer of a polymeric film-forming composition and a second layer of a second polymeric composition which comprises a thermoset resin.
Claim 7
Dependent Claim
41 words
An element according to claim 1 wherein the support and the fibers are composed of electrically insulating material, and the element further comprises an electrically insulating layer of polymeric material secured to the surface of the fibers remote from the support.
Claim 8
Dependent Claim
19 words
An element according to claim 6 which is flexible and whose neutral bending axis passes through the conductive layer.
Claim 9
Dependent Claim
25 words
An element according to claim 1 wherein the fibers are in the form of a non-woven fibrous mat which is partially embedded in the support.
Claim 10
Dependent Claim
16 words
An element according to claim 8 wherein the fibrous mat is 0.07 to 0.6 mm thick.
Claim 11
Dependent Claim
12 words
An element according to claim 1 wherein the fibers comprise glass fibers.
Claim 12
Dependent Claim
18 words
An element according to claim 10 wherein the fibers have an average diameter of 3 to 50 microns.
Claim 13
Dependent Claim
59 words
An element according to claim 1 wherein the support is in the form of a sheet, both faces of the sheet having randomly distributed fibers partially protruding therefrom and partially embedded therein, the first portions of the fibers which protrude from the support surfaces having solid electrically conductive material adherent thereto, thus forming more than one electrically conductive layer.
Claim 14
Dependent Claim
42 words
An element according to claim 12 wherein the support and the fibers are composed of electrically insulating material, and the element further comprises an electrically insulating layer of polymeric material secured to the surface of each conductive layer remote from the support.
Claim 15
Dependent Claim
18 words
An element according to claim 1 wherein the conductive layer has a plurality of randomly distributed voids therein.
Claim 16
Dependent Claim
75 words
An element according to claim 1 which further comprises an electrically insulating layer of polymeric material comprising a backing layer of a continuous film-forming polymeric composition and an adherent layer of a polymeric composition having a softening point which is lower than either the backing layer or the support, the adherent layer being secured to the surface of the conductive layer remote from the support and filling substantially all the voids in the conductive layer.
Claim 17
Dependent Claim
23 words
An electrically conductive element according to claim 1 which further comprises a layered structure having a plurality of electrically conductive elements laminated together.
Claim 18
Dependent Claim
14 words
An element according to claim 1 wherein the support is substantially impermeable to water.
Claim 19
Dependent Claim
31 words
An element according to claim 1 wherein the conductive layer is one obtained by depositing on the fibers an aqueous dispersion of conductive particles, and removing the water from the dispersion.
Claim 20
Dependent Claim
26 words
An element according to claim 18 which further comprises a cationic wetting agent at the interface between the fibers and the aqueous dispersion of conductive particles.
Claim 21
Dependent Claim
29 words
An element according to claim 1 wherein the solid conductive material is selected from the group consisting of carbon black, graphite and a blend of carbon black and graphite.
Claim 22
Dependent Claim
37 words
An element according to claim 1 which further comprises at least two spaced-apart electrodes which can be connected to a source of electrical power and which when so connected cause current to pass through the conductive layer.
Claim 23
Dependent Claim
21 words
An element according to claim 1 wherein the conductive layer has a resistance of 10 to 150,000 ohms per electrical square.
Claim 24
Dependent Claim
80 words
A process for the preparation of an electrically conductive element which comprises (a) depositing a liquid composition comprising an aqueous dispersion of electrically conductive particles onto the protruding fibers of a substrate which comprises a support and randomly distributed fibers having first portions which protrude from the support and second portions which are embedded in the support, the support and the portions of the fibers embedded therein being substantially impervious to the liquid composition; and (b) drying the aqueous dispersion.
Claim 25
Dependent Claim
80 words
A process for the preparation of an electrically conductive element which comprises (a) depositing a liquid composition comprising an aqueous dispersion of electrically conductive particles onto the protruding fibers of a substrate which comprises a support and randomly distributed fibers having first portions which protrude from the support and second portions which are embedded in the support, the support and the portions of the fibers embedded therein being substantially impervious to the liquid composition; and (b) drying the aqueous dispersion.
Claim 26
Dependent Claim
18 words
A process according to claim 23 wherein the support is a flexible continuous film of hydrophobic polymeric material.
Claim 27
Dependent Claim
25 words
A process according to claim 24 which further comprises washing the substrate with an aqueous solution comprising a cationic wetting agent before applying the dispersion.
Claim 28
Dependent Claim
16 words
A process according to claim 23 wherein the liquid composition is substantially free of reinforcing fibers.
Claim 29
Dependent Claim
19 words
A process according to claim 23 wherein the liquid composition is applied to the substrate by a printing process.
Claim 30
Dependent Claim
19 words
A process according to claim 27 wherein the liquid composition is applied to the substrate by silk screen printing.
Claim 31
Dependent Claim
19 words
A process according to claim 27 wherein the liquid composition is applied to the substrate in a discontinuous pattern.
Claim 32
Dependent Claim
38 words
A process according to claim 23 wherein the randomly distributed fibers comprise a non-woven fibrous mat of glass fibers having an average diameter of 3 to 50 microns, the mat having a thickness of 0.07 to 0.6 mm.
Claim 33
Dependent Claim
61 words
A process according to claim 23 which further comprises placing at least two spaced-apart electrodes on the protruding fibers of the substrate prior to applying the liquid composition, and applying the liquid composition onto the electrodes and the fibers, whereby after step (2) connection of the electrodes to a source of electrical power causes current to flow through the conductive element.
Claim 34
Dependent Claim
70 words
A process according to claim 23 which further comprises placing at least two spaced-apart electrodes on the support before embedding the second portions of the randomly distributed fibers in the support, the randomly distributed fibers extending over the electrodes, and applying the liquid composition onto the protruding fibers, whereby after step (2) connection of the electrodes to a source of electrical power causes current to flow through the conductive element.
Claim 35
Dependent Claim
28 words
A process according to claim 23 wherein more than one coating of the liquid composition is deposited, the first coating being solidified before the second coating is deposited.
Claim 36
Dependent Claim
23 words
A process according to claim 23 wherein more than one coating of the liquid composition is deposited, all coatings being solidified at once.
Claim 37
Dependent Claim
52 words
A process according to claim 23 wherein the conductive particles are selected from carbon black, graphite and mixtures of carbon black and graphite, and the liquid composition comprises, as binder for said particles, an alkali-stabilized colloidal silica in the form of dispersed particles having a particle size of 1 to 100 millimicrons.
References Cited (Backward Citations)
US1872581A
Cited
US2803566A
Cited
US2734835A
Cited
US2891228A
Cited
US2991257A
Cited
US2952761A
Cited
US3400254A
Cited
US3837988A
Cited
GB1243898A
Cited
GB1283444A
Cited
GB1332395A
Cited
US3730822A
Cited
US3900654A
Cited
GB1383162A
Cited
US3839134A
Cited
US3859504A
Cited
DE2232558C3
Cited
DE2401203C3
Cited
US3876968A
Cited
US4367398A
Cited
US3952116A
Cited
DE2515897C3
Cited
US4115917A
Cited
US4185137A
Cited
US4084031A
Cited
US4061898A
Cited
US4169911A
Cited
US4158078A
Cited
US4330704A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |