Patent US4596670A successfully refreshed from Google Patents.
US4596670A
Expired / Lapsed
US
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EMI shielding effectiveness of thermoplastics
Assignee: General Electric Co
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Filing: 1983-10-25
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Granted: 1986-06-24
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Expires: 2003-10-25
Abstract
Abstract Improved surface conductivity and EMI shielding effectiveness at high frequencies are obtained in thermoplastic compositions by the incorporation therein of a novel, synergistic combination of conductive fillers.
Inventors
- 👤 Nan-I Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:27
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0081; H05K9/0088; C; C08; C08K; C08K3/00; C08K3/02; C08K3/04; C08K3/08; H01; H01B; H01B1/00; H01B1/20; H01B1/22; H01B1/24
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
98 words
A conductive thermoplastic polymeric composition comprising (a) a thermoplastic resin or resin blend and (b) a synergistic combination of conductive fillers consisting essentially of (1) from about 25 to about 50% by weight based on the total composition of metal flake, (2) from about 2 to about 12% by weight based on the total composition of conductive carbon, metal or metal coated fiber and (3) from about 2 to about 15% by weight based on the total composition of conductive carbon powder, wherein the weight ratio of metal flake to fiber is from about 4:1 to about 14:1.
Claim 2
Dependent Claim
98 words
A conductive thermoplastic polymeric composition comprising (a) a thermoplastic resin or resin blend and (b) a synergistic combination of conductive fillers consisting essentially of (1) from about 25 to about 50% by weight based on the total composition of metal flake, (2) from about 2 to about 12% by weight based on the total composition of conductive carbon, metal or metal coated fiber and (3) from about 2 to about 15% by weight based on the total composition of conductive carbon powder, wherein the weight ratio of metal flake to fiber is from about 4:1 to about 14:1.
Claim 3
Dependent Claim
39 words
The composition of claim 1 wherein the thermoplastic resin (a) is selected from the group consisting of polyesters, polycarbonates, polyamides, polyphenylene ethers, co-polyestercarbonates, polystyrenes, acrylonitrile butadiene styrene copolymers, polyarylate ether sulfones or ketones, polyamide imides, polyetherimides and blends thereof.
Claim 4
Dependent Claim
29 words
A composition as defined in claim 2 wherein the polyester has repeating units of the general formula ##STR16## wherein n is a whole number of from 2 to 4.
Claim 5
Dependent Claim
11 words
The composition of claim 3 wherein the polyester is poly(1,4-butylene terephthalate).
Claim 6
Dependent Claim
11 words
The composition of claim 3 wherein the polyester is poly(ethylene terephthalate).
Claim 7
Dependent Claim
17 words
A composition of claim 2 wherein the polycarbonate is an aromatic polycarbonate derived from 2,2 bis(4-hydroxy phenyl)propane.
Claim 8
Dependent Claim
11 words
A composition of claim 2 wherein the polyamide is Nylon 6,6.
Claim 9
Dependent Claim
19 words
A composition of claim 2 wherein the thermoplastic resin (a) is a blend of poly(ethylene terephthalate) and poly(1,4-butylene terephthalate).
Claim 10
Dependent Claim
18 words
A composition of claim 2 wherein the thermoplastic resin (a) is a blend of polycarbonate and poly(1,4-butylene terephthalate).
Claim 11
Dependent Claim
18 words
A composition of claim 2 wherein the thermoplastic resin (a) is a blend of polycarbonate and poly(ethylene terephthalate).
Claim 12
Dependent Claim
13 words
The composition of claim 2 wherein the thermoplastic condensation polymer is polyphenylene ether.
Claim 13
Dependent Claim
39 words
The composition of claim 11 which further comprises a rubber or a rubber modified thermoplastic resin selected from the group consisting of high impact polystyrene, rubber modified alpha-substituted or para-substituted styrene polymers, ethylene-propylene rubber and ethylene propylene-diene monomer rubbers.
Claim 14
Dependent Claim
21 words
The composition of claim 2 wherein the thermoplastic condensation polymer (a) is a blend of polyphenylene ether and high impact polystyrene.
Claim 15
Dependent Claim
15 words
A composition as defined in claim 2 which further comprises a thermoplastic addition polymer resin.
Claim 16
Dependent Claim
33 words
The composition of claim 14 wherein the thermoplastic addition polymer resin is selected from the group consisting of a styrene resin, an alkyl acrylate resin or a mixture of any of the foregoing.
Claim 17
Dependent Claim
14 words
The composition of claim 15 wherein the thermoplastic addition polymer resin is acrylonitrilebutadiene-styrene resin.
Claim 18
Dependent Claim
10 words
The composition of claim 6 which further comprises acrylonitrile-butadiene-styrene resin.
Claim 19
Dependent Claim
29 words
The composition of claim 15 wherein the thermoplastic addition polymer is a graft copolymer selected from the group consisting of core-shell type acrylic elastomers, acrylic copolymers and vinylic copolymers.
Claim 20
Dependent Claim
19 words
The composition of claim 15 wherein the addition polymer is a blend of a graft copolymer and ethylene ethylacrylate.
Claim 21
Dependent Claim
38 words
A composition as defined in claim 2 which further comprises a rubber or a rubber modified resin selected from the group consisting essentially of high impact polystyrene, rubber modified substituted styrene resins, ethylene-propylene-diene monomer rubbers and ethylene-propylene rubbers.
Claim 22
Dependent Claim
25 words
The composition as defined in claim 1 wherein the metal flake is present in an amount of from about 30 to about 40% by weight.
Claim 23
Dependent Claim
33 words
The composition as defined in claim 1 wherein the metal flake is selected from the group consisting essentially of aluminum flake, nickel flake, copper flake, silver flake and flakes prepared from alloys thereof.
Claim 24
Dependent Claim
13 words
The composition of claim 21 wherein the flake is Aluminum or aluminum alloy.
Claim 25
Dependent Claim
20 words
The composition of claim 1 wherein the weight ratio of flake to fiber is from about 6:1 to about 10:1.
Claim 26
Dependent Claim
28 words
The composition of claim 1 wherein the conductive fiber is present in an amount of from about 4 to about 8% by weight based on the total composition.
Claim 27
Dependent Claim
37 words
The composition of claim 1 wherein the conductive fiber is a metal fiber selected from the group consisting essentially of aluminum fiber, stainless steel fibers, nickel fibers, copper fibers, silver fibers and fiber prepared from alloys thereof.
Claim 28
Dependent Claim
27 words
The composition of claim 1 wherein the conductive fiber is a metal coated fiber selected from the group consisting essentially of metal coated glass and carbon fibers.
Claim 29
Dependent Claim
24 words
The composition of claim 27 wherein the metal coating is selected from the group consisting essentially of nickel, aluminum, copper, silver and alloys thereof.
Claim 30
Dependent Claim
15 words
The composition of claim 27 wherein the metal coated fiber is aluminum coated glass fiber.
Claim 31
Dependent Claim
15 words
The composition of claim 27 wherein the metal coated fiber is nickel coated graphite fiber.
Claim 32
Dependent Claim
12 words
The composition of claim 1 wherein the conductive fiber is carbon fiber.
Claim 33
Dependent Claim
29 words
The composition of claim 1 wherein the conductive carbon powder is present in an amount of from about 3% to about 10% by weight based on the total composition.
Claim 34
Dependent Claim
19 words
The composition of claim 1 which further comprises from about 3 to about 25% by weight of glass fiber.
Claim 35
Dependent Claim
21 words
The composition as defined in claim 2 which further comprises from about 3 to about 25% by weight of glass fibers.
Claim 36
Dependent Claim
21 words
The composition as defined in claim 14 which further comprises from about 3 to about 25% by weight of glass fibers.
Claim 37
Dependent Claim
21 words
The composition as defined in claim 20 which further comprises from about 3 to about 25% by weight of glass fibers.
Claim 38
Dependent Claim
14 words
The composition of claim 1 which further comprises an effective amount of flame retardant.
Claim 39
Dependent Claim
14 words
The composition of claim 33 which further comprises an effective amount of flame retardant.
Claim 40
Dependent Claim
33 words
The composition of claim 37 wherein the flame retardant is selected from the group consisting essentially of halogenated bisphenols based polycarbonate and phosphorus compounds, either alone or in combination with an antimony compound.
Claim 41
Dependent Claim
15 words
The composition of claim 1 wherein the metal fiber is aluminum or aluminum alloy fiber.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-06-23 | 1989-12-23 | 1990-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-23 | 1993-12-23 | 1994-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-23 | 1997-12-23 | 1998-06-24 | $7700.00 | Window Closed / Lapsed |