Patent US3884870A successfully refreshed from Google Patents.
US3884870A
Expired / Lapsed
US
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Polyethylene terephthalate film
Assignee: Celanese Corp
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Filing: 1974-07-15
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Granted: 1975-05-20
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Expires: 1994-07-15
Abstract
Abstract A biaxially oriented polyethylene terephthalate film having excellent clarity in combination with good handleability. The film of the present invention is characterized by the inclusion of about 0.3 to about 2.5 percent by weight of a small particle size inert additive having an average particle size ranging between about 10 and 1000 millimicrons. The film furthermore includes a large particle size inert additive present in a concentration of about 0.002 percent to about 0.018 percent by weight of a large particle size inert additive having an average particle size in the range of between about 0.5 and 30 microns.
Inventors
- 👤 Keith D Dodson
- 👤 Thomas G Squires
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:12
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/34; C08K3/01; C08K3/013; C08K3/02; C08K3/08; C08K3/18; C08K3/24; C08K3/26; C08K3/30; C08K3/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
153 words
A BIAXIALLY ORIENTED POLYETHYLENE TEREPHTHALATE FILM CHARACTERIZED BY THE INCLUSION OF A SMALL PARTICLE SIZE INERT ADDITIVE HAVING AN AVERAGE PARTICLE SIZE RANGING BETWEEN ABOUT 10 AND 1,000 MILLIMICRONS AND PROVIDED IN A CONCENTRATION IN THE RANGE OF BETWEEN ABOUT 0.3 PERCENT AND 2.5 PERCENT BY WEIGHT OF THE TOTAL FILM AND FURTHER CHARACTERIZED BY THE INCLUSION OF A LARGE PARTICLE SIZE INERT ADDITIVE HAVING AN AVERAGE PARTICLE SIZE IN THE RANGE OF BETWEEN ABOUT 0.5 AND 30 MICRONS, SAID LARGE PARTICLE SIZE INERT ADDITIVE PRESENT IN A CONCENTRATION IN THE RANGE OF BETWEEN ABOUT 0.002 PERCENT AND 0.018 PERCENT BY WEIGHT OF THE FILM, SAID LARGE PARTICLE SIZE AND SAID SMALL PARTICLE SIZE INERT ADDITIVES BEING SUBSTANTIALLY COMPLETELY DISPERSED THROUGHOUT SAID FILM WHEREIN SAID FILM HAS A THICKNESS NO GREATER THEN 2 MILES, A HAZE NOT IN EXCESS OF 2.5 PERCENT, AND A KINETIC COEFFICIENT OF FRICTION NOT IN EXCESS OF 0.7.
Claim 2
Dependent Claim
153 words
A BIAXIALLY ORIENTED POLYETHYLENE TEREPHTHALATE FILM CHARACTERIZED BY THE INCLUSION OF A SMALL PARTICLE SIZE INERT ADDITIVE HAVING AN AVERAGE PARTICLE SIZE RANGING BETWEEN ABOUT 10 AND 1,000 MILLIMICRONS AND PROVIDED IN A CONCENTRATION IN THE RANGE OF BETWEEN ABOUT 0.3 PERCENT AND 2.5 PERCENT BY WEIGHT OF THE TOTAL FILM AND FURTHER CHARACTERIZED BY THE INCLUSION OF A LARGE PARTICLE SIZE INERT ADDITIVE HAVING AN AVERAGE PARTICLE SIZE IN THE RANGE OF BETWEEN ABOUT 0.5 AND 30 MICRONS, SAID LARGE PARTICLE SIZE INERT ADDITIVE PRESENT IN A CONCENTRATION IN THE RANGE OF BETWEEN ABOUT 0.002 PERCENT AND 0.018 PERCENT BY WEIGHT OF THE FILM, SAID LARGE PARTICLE SIZE AND SAID SMALL PARTICLE SIZE INERT ADDITIVES BEING SUBSTANTIALLY COMPLETELY DISPERSED THROUGHOUT SAID FILM WHEREIN SAID FILM HAS A THICKNESS NO GREATER THEN 2 MILES, A HAZE NOT IN EXCESS OF 2.5 PERCENT, AND A KINETIC COEFFICIENT OF FRICTION NOT IN EXCESS OF 0.7.
Claim 3
Dependent Claim
66 words
A film in accordance with claim 1 wherein said small particle size inert additive is present in a concentration in the range of between about 0.4 percent and 2 percent by weight of said polyethylene terephthalate film and said large particle size additive is present in a concentration in the range of between about 0.005 percent and 0.015 percent by weight of said polyethylene terephthalate film.
Claim 4
Dependent Claim
23 words
A film in accordance with claim 1 wherein said polyethylene terephthalate film has an intrinsic viscosity in excess of 0.3 deciliter per gram.
Claim 5
Dependent Claim
40 words
A film in accordance with claim 1 wherein said small particle size inert additive is selected from the group consisting of silica, calcium carbonate, calcined aluminum silicate, hydrated aluminum silicate, calcium phosphate, alumina, barium sulfate, magnesium sulfate and diatomaceous earth.
Claim 6
Dependent Claim
16 words
A film in accordance with claim 4 wherein said small particle size inert additive is alumina.
Claim 7
Dependent Claim
14 words
A film in accordance with claim 4 wherein said small inert additive is silica.
Claim 8
Dependent Claim
43 words
A film in accordance with claim 1 wherein said large particle size inert additive is selected from the group consisting of calcium carbonate, calcined aluminum silicate, hydrated aluminum silicate, magnesium silicate, calcium silicate, calcium phosphate, silica, alumina, barium sulfate, mica and diatomaceous earth.
Claim 9
Dependent Claim
17 words
A film in accordance with claim 7 wherein said large particle size inert additive is calcium carbonate.
Claim 10
Dependent Claim
18 words
A film in accordance with claim 7 wherein said large particle size inert additive is hydrated aluminum silicate.
References Cited (Backward Citations)
US3821156A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |