US4693932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oriented polyester film
Assignee: Toyobo Co Ltd
•
Filing: 1986-05-02
•
Granted: 1987-09-15
•
Expires: 2006-05-02
Abstract
Abstract An oriented polyester film comprising ethylene terephthalate as the major repeating units, which comprises 0.01 to 1.0% by weight of silica particles and/or titanium dioxide particles having each an average particle size of 0.01 to 0.5μ and 0.005 to 1.0% by weight of calcium carbonate having an average particle size of 0.01 to 0.5μ, which provides an oriented polyester film for the base film of video tape which has a flatness on the surface and has excellent slipperiness, abrasion resistance and running characteristics as well as excellent magnetic transducer characteristics.
Inventors
- 👤 Katsuaki Kuze
- 👤 Yasuhiro Nishino
- 👤 Yujiro Matsuyama
- 👤 Kozo Maeda
- 👤 Masahiro Kobayashi
- 👤 Tadashi Okudaira
- 👤 Tsuyoshi Hongo
- 👤 Osamu Makimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:02
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/18; C08K3/24; C08K3/26; C08J; C08J5/00; C08J5/18; C08K3/20; C08K3/22; C08K3/34; C08K3/36; G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73923; G11B5/73927; C08J2367/00; C08J2367/02; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/91; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/258; Y10T428/259; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
117 words
An oriented polyester film for manufacturing a magnetic recording tape which comprises a polyester composed of ethylene terephthalate as the major repeating units, and (I) 0.01 to 1.0% by weight of particles selected from the group consisting of silica particles and titanium dioxide particles having each an average particle size of 0.01 to 0.5μ, and (II) 0.005 to 1.0% by weight of calcium carbonate particles having an average particle size of 0.01 to 0.5μ, provided that an amount of particles which have a particle size of not less than 5μ is not more than 0.5% by weight based on the total weight of said particles of (I) and (II) when they are incorporated in a slurry state.
Claim 2
Dependent Claim
117 words
An oriented polyester film for manufacturing a magnetic recording tape which comprises a polyester composed of ethylene terephthalate as the major repeating units, and (I) 0.01 to 1.0% by weight of particles selected from the group consisting of silica particles and titanium dioxide particles having each an average particle size of 0.01 to 0.5μ, and (II) 0.005 to 1.0% by weight of calcium carbonate particles having an average particle size of 0.01 to 0.5μ, provided that an amount of particles which have a particle size of not less than 5μ is not more than 0.5% by weight based on the total weight of said particles of (I) and (II) when they are incorporated in a slurry state.
Claim 3
Dependent Claim
24 words
An oriented polyester film according to claim 1, wherein each silica and titanium dioxide particle has an average particle size of 0.01 to 0.4μ.
Claim 4
Dependent Claim
24 words
An oriented polyester film according to claim 1, wherein each silica and titanium dioxide particle has an average particle size of 0.01 to 0.3μ.
Claim 5
Dependent Claim
24 words
An oriented polyester film according to claim 1, wherein each silica and titanium dioxide particle has an average particle size of 0.03 to 0.1μ.
Claim 6
Dependent Claim
26 words
An oriented polyester film according to claim 1, wherein the silica and titanium dioxide particles are incorporated in an amount of 0.02 to 0.6% by weight.
Claim 7
Dependent Claim
26 words
An oriented polyester film according to claim 1, wherein the silica and titanium dioxide particles are incorporated in an amount of 0.05 to 0.5% by weight.
Claim 8
Dependent Claim
26 words
An oriented polyester film according to claim 1, wherein the silica and titanium dioxide particles are incorporated in an amount of 0.05 to 0.3% by weight.
Claim 9
Dependent Claim
22 words
An oriented polyester film according to claim 1, wherein the calcium carbonate particles have an average particles size of 0.03 to 0.49μ.
Claim 10
Dependent Claim
22 words
An oriented polyester film according to claim 1, wherein the calcium carbonate particles have an average particle size of 0.04 to 0.48μ.
Claim 11
Dependent Claim
22 words
An oriented polyester film according to claim 1, wherein the calcium carbonate particles have an average particle size of 0.04 to 0.1μ.
Claim 12
Dependent Claim
22 words
An oriented polyester film according to claim 1, wherein the calcium carbonate particles have an average particle size of 0.1 to 0.48μ.
Claim 13
Dependent Claim
24 words
An oriented polyester film according to claim 1, wherein the calcium carbonate particles are incorporated in an amount of 0.01 to 0.6% by weight.
Claim 14
Dependent Claim
24 words
An oriented polyester film according to claim 1, wherein the calcium carbonate particles are incorporated in an amount of 0.02 to 0.5% by weight.
Claim 15
Dependent Claim
24 words
An oriented polyester film according to claim 1, wherein the calcium carbonate particles are incorporated in an amount of 0.02 to 0.2% by weight.
Claim 16
Dependent Claim
25 words
An oriented polyester film according to claim 1, wherein the average particle size or calcium carobonate is larger than that of silica and titanium dioxide.
Claim 17
Dependent Claim
16 words
An oriented polyester film according to claim 1, wherein the film is a biaxially oriented film.
Claim 18
Dependent Claim
20 words
An oriented polyester film according to claim 1, wherein the film serves as a base film for a video tape.
References Cited (Backward Citations)
US3790435A
Cited
US3980611A
Cited
US3821156A
Cited
US4198458A
Cited
US4138386A
Cited
US4348446A
Cited
US4242396A
Cited
US4375494A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-14 | 1991-03-16 | 1991-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-14 | 1995-03-16 | 1995-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-14 | 1999-03-16 | 1999-09-15 | $7700.00 | Window Closed / Lapsed |