Patent US4421887A successfully refreshed from Google Patents.
US4421887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biaxially oriented polyester films
Assignee: Teijin Ltd
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Filing: 1982-05-20
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Granted: 1983-12-20
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Expires: 2002-05-20
Abstract
Abstract A biaxially oriented polyester film composed of a polyester composition comprising (A) 100 parts by weight of a substantially linear polyalkylene terephthalate having ethylene terephthalate as a main structural component, (B) 0.01 to 5 parts by weight of an ester of an aliphatic polyol having at least 4 hydroxyl groups in the molecule with an aliphatic monocarboxylic acid having at least 8 carbon atoms, and (C) not more than 0.8 part by weight of fine inorganic particles having an average particle diameter of not more than about 1 micron and being substantially insoluble in the polyalkylene terephthalate. The aforesaid biaxially oriented polyester film is useful as a base of magnetic tapes.
Inventors
- 👤 Shigeru Horie
- 👤 Takamasa Asano
- 👤 Tetsuo Ichihashi
- 👤 Hideo Katoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:30
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; C08K; C08K3/00; C08K5/00; C08K5/04; C08K5/10; C08K5/101; C08K5/103; C08J2367/00; C08J2367/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
104 words
A biaxially oriented polyester film composed of a polyester composition comprising (A) 100 parts by weight of a substantially linear polyalkylene terephthalate having ethylene terephthalate as a main structural component, (B) 0.01 to 5 parts by weight of a partial ester of an aliphatic polyol having 4 to 6 hydroxyl groups and 5 or 6 carbon atoms in the molecule with an aliphatic monocarboxylic acid having 8 to 30 carbon atoms, and (C) not more than 0.8 part by weight of fine inorganic particles having an average particle diameter of not more than about 1 micron and being substantially insoluble in the polyalkylene terephthalate.
Claim 2
Dependent Claim
104 words
A biaxially oriented polyester film composed of a polyester composition comprising (A) 100 parts by weight of a substantially linear polyalkylene terephthalate having ethylene terephthalate as a main structural component, (B) 0.01 to 5 parts by weight of a partial ester of an aliphatic polyol having 4 to 6 hydroxyl groups and 5 or 6 carbon atoms in the molecule with an aliphatic monocarboxylic acid having 8 to 30 carbon atoms, and (C) not more than 0.8 part by weight of fine inorganic particles having an average particle diameter of not more than about 1 micron and being substantially insoluble in the polyalkylene terephthalate.
Claim 3
Dependent Claim
20 words
The film of claim 1 wherein the aliphatic polyol is erythritol, threitol, pentaerythritol, arabitol, adonitol, talitol, sorbitol, mannitol or iditol.
Claim 4
Dependent Claim
12 words
The film of claim 1 wherein the aliphatic monocarboxylic acid is linear.
Claim 5
Dependent Claim
15 words
the film of claim 1 wherein the ester (B) is a mono-, di- or tri-ester.
Claim 6
Dependent Claim
19 words
The film of claim 1 wherein the proportion of the ester (B) is 0.05 to 2 parts by weight.
Claim 7
Dependent Claim
12 words
The film of claim 1 wherein the polyalkylene terephthalate is polyethylene terephthalate.
Claim 8
Dependent Claim
105 words
A magnetic tape made of a biaxially oriented polyester film as the base material, said film being composed of a poolyester composition comprising (A) 100 parts by weight of polyethylene terephthalate, (B) 0.05 to 4 parts by weight of a partial ester of an aliphatic polyol having 4 to 6 hydroxyl groups and 5 or 6 carbon atoms in the molecule with an aliphatic monocarboxylic acid having 8 to 30 carbon atoms, and (C) not more than 0.5 part by weight of fine inorganic particles having an average particle diameter of not more than about 0.5 micron and being substantially insoluble in the polyethylene terephthalate.
Claim 9
Dependent Claim
105 words
A magnetic tape made of a biaxially oriented polyester film as the base material, said film being composed of a poolyester composition comprising (A) 100 parts by weight of polyethylene terephthalate, (B) 0.05 to 4 parts by weight of a partial ester of an aliphatic polyol having 4 to 6 hydroxyl groups and 5 or 6 carbon atoms in the molecule with an aliphatic monocarboxylic acid having 8 to 30 carbon atoms, and (C) not more than 0.5 part by weight of fine inorganic particles having an average particle diameter of not more than about 0.5 micron and being substantially insoluble in the polyethylene terephthalate.
References Cited (Backward Citations)
US3516957A
Cited
US4093695A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |