Patent US4496583A successfully refreshed from Google Patents.
US4496583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Paper-like polyester fiber sheet and process for producing the same
Assignee: Teijin Ltd
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Filing: 1983-02-24
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Granted: 1985-01-29
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Expires: 2003-02-24
Abstract
Abstract A paper-like polyester sheet having an enhanced filtering property, an excellent mechanical strength and satisfactory touch and appearance, comprises polyester staple fibers and has a coefficient of air flow resistance of 1,000 to 50,000 dyn.s/cm 4 at a volume fraction of the fibers of from 0.01 to 0.24.
Inventors
- 👤 Tamio Yamamoto
- 👤 Tsukasa Kobayashi
- 👤 Tadashi Hirakawa
- 👤 Makoto Yoshida
- 👤 Masumi Okumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:35
CPC Classifications
D; D21; D21H; D21H13/00; D21H13/10; D21H13/20; D21H13/24; Y; Y10; Y10T; Y10T442/00; Y10T442/60; Y10T442/696; Y10T442/697
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
62 words
A paper-like polyester fiber sheet, comprising polyester staple fibers and having a coefficient of air flow resistance of from 2,500 to 23,500 dyn.s/cm 4 at a volume fraction of the fibers of from 0.01 to 0.24, said polyester staple fibers containing drawn polyester staple fibers each having a denier of 0.01 to 0.9 and a length of from 0.3 to 20 mm.
Claim 2
Dependent Claim
62 words
A paper-like polyester fiber sheet, comprising polyester staple fibers and having a coefficient of air flow resistance of from 2,500 to 23,500 dyn.s/cm 4 at a volume fraction of the fibers of from 0.01 to 0.24, said polyester staple fibers containing drawn polyester staple fibers each having a denier of 0.01 to 0.9 and a length of from 0.3 to 20 mm.
Claim 3
Dependent Claim
20 words
A sheet as claimed in claim 1, wherein said polyester staple fibers consist essentially of drawn polyester staple fibers alone.
Claim 4
Dependent Claim
18 words
A sheet as claimed in claim 1, wherein the individual drawn polyester staple fibers have substantially no crimp.
Claim 5
Dependent Claim
27 words
A sheet as claimed in claim 1, wherein said polyester staple fibers consist essentially of a blend of undrawn polyester staple fibers and drawn polyester staple fibers.
Claim 6
Dependent Claim
27 words
A sheet as claimed in claim 4, wherein said undrawn polyester staple fibers in said blend are present in an amount of at least 20% by weight.
Claim 7
Dependent Claim
20 words
A sheet as claimed in claim 5, wherein said undrawn polyester staple fibers have a denier of 1.3 or less.
Claim 8
Dependent Claim
20 words
A sheet as claimed in claim 6, wherein the denier of said undrawn polyester staple fibers is 0.9 or less.
Claim 9
Dependent Claim
29 words
A sheet as claimed in claim 5, wherein said undrawn polyester staple fibers have a birefringence of from 0.01 to 0.06 and a specific gravity of 1.35 or less.
Claim 10
Dependent Claim
23 words
A sheet as claimed in claim 2 wherein the individual drawn polyester staple fibers have a length of from 1 to 15 mm.
Claim 11
Dependent Claim
25 words
A sheet as claimed in claim 5 wherein said undrawn polyester staple fibers are present in an amount of from 30 to 90% by weight.
Claim 12
Dependent Claim
22 words
A sheet as claimed in claim 7 wherein said undrawn polyester staple fibers have a length of from 1 to 15 mm.
Claim 13
Dependent Claim
38 words
A sheet as claimed in claim 1 further comprising up to 20% by weight of staple fibers selected from the group consisting of water-insoluble polyvinylalcohol fibers, polyamide fibers, polyolefin fibers, rayon fibers, wood pulp, glass fibers and asbestos.
Claim 14
Dependent Claim
38 words
A sheet as claimed in claim 4 further comprising up to 20% by weight of staple fibers selected from the group consisting of water-insoluble polyvinylalcohol fibers, polyamide fibers, polyolefin fibers, rayon fibers, wood pulp, glass fibers and asbestos.
Claim 15
Dependent Claim
19 words
A sheet as claimed in claim 1 wherein the airflow resistance is from 2,500 to 20,000 dyn.s/cm 4 .
Claim 16
Dependent Claim
19 words
A sheet as claimed in claim 1 wherein the volume fraction of the fibers is from 0.01 to 0.20.
Claim 17
Dependent Claim
19 words
A sheet as claimed in claim 14 wherein the volume fraction of the fibers is from 0.01 to 0.20.
Claim 18
Dependent Claim
15 words
A sheet as claimed in claim 1 wherein said fibers are polyethylene terephthalate staple fibers.
Claim 19
Dependent Claim
42 words
A sheet as claimed in claim 1 wherein said fibers contain up to 30% by weight of at least one additive selected from the group consisting of a delustering agent, an optical brightening agent, an antistatic agent and a flame retarding agent.
Claim 20
Dependent Claim
42 words
A sheet as claimed in claim 17 wherein said fibers contain up to 30% by weight of at least one additive selected from the group consisting of a delustering agent, an optical brightening agent, an antistatic agent and a flame retarding agent.
Claim 21
Dependent Claim
20 words
A sheet as claimed in claim 10 wherein said undrawn polyester staple fibers have a denier of 1.3 or less.
Claim 22
Dependent Claim
29 words
A sheet as claimed in claim 10, wherein said undrawn polyester staple fibers have a birefringence of from 0.01 to 0.06 and a specific gravity of 1.35 or less.
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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) | 1988-01-29 | 1988-07-30 | 1989-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-29 | 1992-07-30 | 1993-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-29 | 1996-07-30 | 1997-01-29 | $7700.00 | Window Closed / Lapsed |