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US4320207A Expired / Lapsed US ⏱️ 0.0 years remaining

Polyester film containing fine powder of crosslinked polymer

Assignee: Diafoil Co Ltd
•
Filing: 1980-04-28
•
Granted: 1982-03-16
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Expires: 2000-04-28
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Abstract

Abstract There is disclosed a polyester film containing from 0.001% to 4% by weight fine particles of a crosslinked polymer having an average diameter of 0.1 to 5μ, said fine particles being derived by pulverization from a crosslinked polymer having a specific surface area of at least 1 m 2 /g and a pore volume of at least 0.1 ml/g. The films of the present invention are useful as high grade films and afford many advantages in various applications, for example, as magnetic tapes, capacitors, photography, printing plate making, releasing and the like.

Inventors

  • 👤 Masamichi Watanabe
  • 👤 Seiji Sakamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 03:07
CPC Classifications
C; C08; C08L; C08L67/00; C08L67/02

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 112 words
A polyester film containing from 0.001% to 4% by weight fine particles of a crosslinked polymer having an average diameter of 0.1 to 5μ, said fine particles containing numerous pores and being derived by pulverization from a crosslinked polymer having a specific area of at least 1 m 2 /g and a pore volume of at least 0.1 ml/g, and having a functional group capable of reacting with the polyester to form a covalent bond or from a crosslinked polymer having no functional group capable of reacting with the polyester and obtained by using at least one member of the class consisting of styrene and an alkyl-substituted styrene as a monovinyl component.
Claim 2
Dependent Claim 112 words
A polyester film containing from 0.001% to 4% by weight fine particles of a crosslinked polymer having an average diameter of 0.1 to 5μ, said fine particles containing numerous pores and being derived by pulverization from a crosslinked polymer having a specific area of at least 1 m 2 /g and a pore volume of at least 0.1 ml/g, and having a functional group capable of reacting with the polyester to form a covalent bond or from a crosslinked polymer having no functional group capable of reacting with the polyester and obtained by using at least one member of the class consisting of styrene and an alkyl-substituted styrene as a monovinyl component.
Claim 3
Dependent Claim 18 words
The polyester film as claimed in claim 1 wherein the fine particles are covalently bonded to the polyester.

References Cited (Backward Citations)

US4007141A Cited
US3928254A Cited
US4118440A Cited
US3935132A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-03-15 1985-09-14 1986-03-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-03-15 1989-09-14 1990-03-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-03-15 1993-09-14 1994-03-16 $7700.00 Window Closed / Lapsed

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