US4101523A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyester films
Assignee: Mitsubishi Chemical Corp
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Filing: 1976-07-16
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Granted: 1978-07-18
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Expires: 1996-07-16
Abstract
Abstract A polyester film is disclosed which comprises a polyester mainly consisting of polyethylene terephthalate and an additive amount of granular calcium terephthalate anhydride particles having a specific volume shape factor. The average particle diameter and additive amount of the granular calcium terephthalate anhydride particles may be controlled so that the film is particularly suitable as a metallized film or a condenser film.
Inventors
- 👤 Masamichi Watanabe
- 👤 Takuo Nakahara
- 👤 Seiji Sakamoto
- 👤 Kunio Bizen
- 👤 Akikazu Yano
- 👤 Yuzo Otani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:37
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/41; C07C51/412; C08; C08G; C08G63/00; C08G63/78; C08K; C08K5/00; C08K5/04; C08K5/09; C08K5/098; C08K7/00; C08K7/16
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
133 words
A polyester film comprising a polyester mainly consisting of polyethylene terephthalate and 0.02 to 0.4% by weight of calcium terephthalate anhydride particles incorporated into the polyester by addition to the reaction medium in which the polyester is formed, said calcium terephthalate anhydride particles having an average particle diameter of 0.2 to 4.5 microns and a volume shape factor, φν, in the range of 0.08 to 0.4, said φν being calculated by the formula: φν = V/D.sup.3 wherein D is the maximum diameter of a particle in the projection plane and V is the volume of the particle, said particulate calcium terephthalate anhydride being formed by reacting a dialkali metal terephthalate with a water-soluble calcium compound and heating the resultant calcium terephthalate to a temperature above 100° C to convert it into its anhydride.
Claim 2
Dependent Claim
133 words
A polyester film comprising a polyester mainly consisting of polyethylene terephthalate and 0.02 to 0.4% by weight of calcium terephthalate anhydride particles incorporated into the polyester by addition to the reaction medium in which the polyester is formed, said calcium terephthalate anhydride particles having an average particle diameter of 0.2 to 4.5 microns and a volume shape factor, φν, in the range of 0.08 to 0.4, said φν being calculated by the formula: φν = V/D.sup.3 wherein D is the maximum diameter of a particle in the projection plane and V is the volume of the particle, said particulate calcium terephthalate anhydride being formed by reacting a dialkali metal terephthalate with a water-soluble calcium compound and heating the resultant calcium terephthalate to a temperature above 100° C to convert it into its anhydride.
Claim 3
Dependent Claim
20 words
The film of claim 1 wherein the particulate calcium terephthalate anhydride has the approximate empirical formula: C.sub.8 H.sub.4 Ca.sub.1 O.sub.4
References Cited (Backward Citations)
US3567693A
Cited
US3657180A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |