US4729921A
Expired / Lapsed
US
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High density para-aramid papers
Assignee: EIDP Inc
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Filing: 1985-09-17
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Granted: 1988-03-08
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Expires: 2005-09-17
Abstract
Abstract High density para-aramid papers comprising 5 to 25 percent, by weight, binder and an amount of para-aramid fibers selected from the group consisting of para-aramid pulp, para-aramid floc and mixtures thereof, compacted to provide a volume percent para-aramid fiber of at least 53 minus 0.13 times the volume percent floc in the paper are useful in the preparation of circuit board substrates having a low coefficient of thermal expansion.
Inventors
- 👤 Edward W. Tokarsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:13
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K1/0366; D; D21; D21H; D21H13/00; D21H13/10; D21H13/20; D21H13/26; D21H5/00; D21H5/12; D21H5/14; D21H5/141; D21H5/143; H05K2201/00; H05K2201/02; H05K2201/0275; H05K2201/0278; H05K2201/0293; H05K2201/06; H05K2201/068; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/253; Y10T428/26; Y10T428/268
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
108 words
High density para-aramid paper for use in an electrical circuit board laminates having low coefficient of thermal expansion comprising 5 to 15 percent, by weight, based on the total solids content of the paper, of a polymeric binder of aramid fibrids and short para-aramid fibers made up of 0-50 volume percent para-aramid pump and 50-100 volume percent para-aramid floc having lengths of 0.8 to 12.7 mm, the fibers being compacted at a nip pressure of 1500 to 5000 lbs/inch (268 to 894 kg/cm) to provide a volume percent para-aramid fiber in the paper of at least 53 minus 0.13 times the volume percent para-aramid floc in the fibers.
Claim 2
Dependent Claim
108 words
High density para-aramid paper for use in an electrical circuit board laminates having low coefficient of thermal expansion comprising 5 to 15 percent, by weight, based on the total solids content of the paper, of a polymeric binder of aramid fibrids and short para-aramid fibers made up of 0-50 volume percent para-aramid pump and 50-100 volume percent para-aramid floc having lengths of 0.8 to 12.7 mm, the fibers being compacted at a nip pressure of 1500 to 5000 lbs/inch (268 to 894 kg/cm) to provide a volume percent para-aramid fiber in the paper of at least 53 minus 0.13 times the volume percent para-aramid floc in the fibers.
Claim 3
Dependent Claim
11 words
The paper of claim 1 wherein the para-aramid is poly(p-phenylene terephthalamide).
Claim 4
Dependent Claim
29 words
The paper of claim 1 wherein the volume percent para-aramid fiber in the paper is at least 63 minus 0.13 times the volume percent para-aramid floc in the fibers.
Claim 5
Dependent Claim
29 words
The paper of claim 2 wherein the volume percent para-aramid fiber in the paper is at least 63 minus 0.13 times the volume percent para-aramid floc in the fibers.
Claim 6
Dependent Claim
17 words
The paper of claim 1 wherein the length of the para-aramid floc is 1.3 to 6.4 mm.
Claim 7
Dependent Claim
13 words
The paper of claim 2 wherein the aramid fibrids are poly(m-phenylene isophthalamide) fibrids.
Claim 8
Dependent Claim
13 words
The paper of claim 3 wherein the aramid fibrids are poly(m-phenylene isophthalamide) fibrids.
Claim 9
Dependent Claim
13 words
The paper of claim 4 wherein the aramid fibrids are poly(m-phenylene isophthalamide) fibrids.
Claim 10
Dependent Claim
35 words
The paper of claim 3 wherein the paper is compacted by being calendered between rigid rolls heated to 125 to 400° C. at a nip pressure of 1500 to 5000 lbs/inch (268 to 894 kg/cm).
Claim 11
Dependent Claim
35 words
The paper of claim 4 wherein the paper is compacted by being calendered between rigid rolls heated to 125 to 400° C. at a nip pressure of 1500 to 5000 lbs/inch (268 to 894 kg/cm).
Claim 12
Dependent Claim
17 words
The paper of claim 2 wherein the length of the para-aramid floc is 1.3 to 6.4 mm.
Claim 13
Dependent Claim
117 words
High density para-aramid paper for use in electrical circuit board laminates having low coefficient of thermal expansion comprising 5 to 15 percent, by weight, of a water dispersible polymeric binder selected from the group consisting of epoxy resins, phenolic resins, polyester resins, polyureas, polyurethanes, melamine formaldehyde resins, and fluorocarbon resins and short para-aramid fibers made up of 0-50 volume percent para-aramid pulp and 50-100 volume percent para-aramid floc having lengths of 0.8 to 12.7 mm, the fibers being compacted at a nip pressure of 1500 to 5000 lbs/inch (268 to 894 kg/cm) to provide a volume percent para-aramid fiber in the paper of a least 53 minus 0.13 times the volume percent para-aramid floc in the fibers.
Claim 14
Dependent Claim
117 words
High density para-aramid paper for use in electrical circuit board laminates having low coefficient of thermal expansion comprising 5 to 15 percent, by weight, of a water dispersible polymeric binder selected from the group consisting of epoxy resins, phenolic resins, polyester resins, polyureas, polyurethanes, melamine formaldehyde resins, and fluorocarbon resins and short para-aramid fibers made up of 0-50 volume percent para-aramid pulp and 50-100 volume percent para-aramid floc having lengths of 0.8 to 12.7 mm, the fibers being compacted at a nip pressure of 1500 to 5000 lbs/inch (268 to 894 kg/cm) to provide a volume percent para-aramid fiber in the paper of a least 53 minus 0.13 times the volume percent para-aramid floc in the fibers.
Claim 15
Dependent Claim
11 words
The paper of claim 12 wherein the para-aramid is poly(p-phenylene terephthalamide).
Claim 16
Dependent Claim
29 words
The paper of claim 12 wherein the volume percent para-aramid fiber in the ptaper is at least 63 minus 0.13 times the volume percent para-aramid floc in the fibers.
Claim 17
Dependent Claim
29 words
The paper of claim 13 wherein the volume percent para-aramid fiber in the paper is at least 63 minus 0.13 times the volume percent para-aramid floc in the fibers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-08 | 1991-09-07 | 1992-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-08 | 1995-09-07 | 1996-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-08 | 1999-09-07 | 2000-03-08 | $7700.00 | Window Closed / Lapsed |