US4461797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyester film with projections and depressions on the surface
Assignee: Teijin Ltd
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Filing: 1981-10-14
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Granted: 1984-07-24
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Expires: 2001-10-14
Abstract
Abstract A polyester film characterized by having many uneven units on its surface, each of said uneven units being composed of a fine projection and a depression existing therearound, and a process for producing aforesaid polyester film, which comprises pre-heating an unstretched polyester film containing internal particles attributed to an inert additive having an average particle diameter of 0.05 to 5 μm and/or a catalyst residue to a temperature of 80° to 120° C.; stretching the film in a first axial direction to 2.6 to 3.5 times at a temperature of 110° to 145° C.; thereafter, stretching the film in a second axial direction at right angles to the first axial direction to 3.0 to 4.0 times at a temperature of 100° to 150° C.; and then heat-setting the stretched film at a temperature of 160° to 240° C.
Inventors
- 👤 Tomio Adachi
- 👤 Hideo Katoh
- 👤 Atsushi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:04
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/10; B29C55/12; B29C55/14; G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73923; G11B5/73927; G11B5/73929; G11B5/73935; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24405; Y10T428/24479; Y10T428/25; Y10T428/259; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
181 words
A biaxially oriented polyester film containing fine particles of inert additives therein characterized by having many uneven units on its surface, each of said uneven units being composed of a fine projection and a depression elliptically existing therearound, said polyester film being a copolymer obtained by the polycondensation of aromatic dibasic acids selected from the group consisting of terephthalic acid, isophthalic acid and naphthalene-2,6-dicarboxylic acid and glycols selected from the group consisting of ethylene glycol, tetramethylene glycol and neopentyl glycol; a homopolymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polyethylene-2,6-naphthalenedicarboxylate; or a polymer blend of polyethylene terephthalate and an ethylene terephthalate/polyethylene glycol block copolymer; wherein each depression of the polyester film surface has an elliptical shape with a long diameter in the range of 2 μm to 50μm; and wherein the following relationship exists between the frequency of occurrence of the uneven units N (per mm 2 ) and the long diameter D (μm) of the depression on the surface of the film surface; when 2≦D<5, 200≦N<3500, when 5≦D<10, 150≦N<2000, when 10≦D<30, 50≦N<800, and when 30≦D≦50, 0≦N≦5.
Claim 2
Dependent Claim
181 words
A biaxially oriented polyester film containing fine particles of inert additives therein characterized by having many uneven units on its surface, each of said uneven units being composed of a fine projection and a depression elliptically existing therearound, said polyester film being a copolymer obtained by the polycondensation of aromatic dibasic acids selected from the group consisting of terephthalic acid, isophthalic acid and naphthalene-2,6-dicarboxylic acid and glycols selected from the group consisting of ethylene glycol, tetramethylene glycol and neopentyl glycol; a homopolymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polyethylene-2,6-naphthalenedicarboxylate; or a polymer blend of polyethylene terephthalate and an ethylene terephthalate/polyethylene glycol block copolymer; wherein each depression of the polyester film surface has an elliptical shape with a long diameter in the range of 2 μm to 50μm; and wherein the following relationship exists between the frequency of occurrence of the uneven units N (per mm 2 ) and the long diameter D (μm) of the depression on the surface of the film surface; when 2≦D<5, 200≦N<3500, when 5≦D<10, 150≦N<2000, when 10≦D<30, 50≦N<800, and when 30≦D≦50, 0≦N≦5.
Claim 3
Dependent Claim
54 words
The biaxially oriented polyester film of claim 1 wherein each uneven unit consists of a projection formed owing to an inert additive and/or a catalyst residue contained in the polyester and a depression around it, said depression being of an elliptical shape having a long diameter along the second axial direction of the film.
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) | 1987-07-24 | 1988-01-23 | 1988-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-24 | 1992-01-23 | 1992-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-24 | 1996-01-23 | 1996-07-24 | $7700.00 | Window Closed / Lapsed |