US4519969A
Expired / Lapsed
US
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Stretched fluorine type film and method for manufacture thereof
Assignee: Unitika Ltd
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Filing: 1984-09-10
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Granted: 1985-05-28
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Expires: 2004-09-10
Abstract
Abstract A biaxially stretched film and a method for the manufacture thereof, containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, having a value of crystallization property, ΔT, expressed by the equation ΔT=T.sub.m -T.sub.c wherein T m (melting point) stands for the peak melting temperature (°C.) found when a sample is heated at a temperature increase rate of 20° C./minute using differential scanning calorimeter (DSC), and T c (crystallizing temperature during fall of temperature) stands for the peak crystallizing temperature (°C.) found when the sample is cooled at a temperature decrease rate of 80° C./minute from the melting point plus 20° C. using said DSC, of not less than 15° C. and not more than 60° C., prepared by a method comprising heating a thermoplastic resin containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer to form a molten resin, extruding the molten resin through a die, and cooling the extruded molten resin at a cooling speed of at least 70° C./second in the range of the melting point minus 10° C. to the melting point minus 100° C. to thereby form a film while simultaneously biaxially stretching said film to at least two times the original size in each of the longitudinal and lateral directions.
Inventors
- 👤 Kunio Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:39
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B29; B29D; B29D7/00; B29K; B29K2027/00; B29K2027/12; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
198 words
A biaxially stretched film containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, having a value of crystallization property, ΔT, expressed by the equation ΔT=T.sub.m -T.sub.c wherein T m (melting point) stands for the peak melting temperature (°C.) found when a sample is heated at a temperature increase rate of 20° C./minute using differential scanning calorimeter (DSC), and T c (crystallizing temperature during fall of temperature) stands for the peak crystallizing temperature (°C.) found when the sample is cooled at a temperature decrease rate of 80° C./minute from the melting point plus 20° C. using said DSC, of not less than 15° C. and not more than 60° C., prepared by a method comprising heating a thermoplastic resin containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer to form a molten resin, extruding the molten resin through a die, and cooling the extruded molten resin at a cooling speed of at least 70° C./second in the range of the melting point minus 10° C. to the melting point minus 100° C. to thereby form a film while simultaneously biaxially stretching said film to at least two times the original size in each of the longitudinal and lateral directions.
Claim 2
Dependent Claim
198 words
A biaxially stretched film containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, having a value of crystallization property, ΔT, expressed by the equation ΔT=T.sub.m -T.sub.c wherein T m (melting point) stands for the peak melting temperature (°C.) found when a sample is heated at a temperature increase rate of 20° C./minute using differential scanning calorimeter (DSC), and T c (crystallizing temperature during fall of temperature) stands for the peak crystallizing temperature (°C.) found when the sample is cooled at a temperature decrease rate of 80° C./minute from the melting point plus 20° C. using said DSC, of not less than 15° C. and not more than 60° C., prepared by a method comprising heating a thermoplastic resin containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer to form a molten resin, extruding the molten resin through a die, and cooling the extruded molten resin at a cooling speed of at least 70° C./second in the range of the melting point minus 10° C. to the melting point minus 100° C. to thereby form a film while simultaneously biaxially stretching said film to at least two times the original size in each of the longitudinal and lateral directions.
Claim 3
Dependent Claim
22 words
A biaxially stretched film according to claim 1, wherein the film is stretched in a range betwen 50° C. and 160° C.
Claim 4
Dependent Claim
22 words
A biaxially stretched film according to claim 1, wherein the film is stretched in a range betwen 70° C. and 150° C.
Claim 5
Dependent Claim
24 words
A biaxially stretched film according to claim 1, wherein the ratio of ethylene to tetrafluoroethylene is in a range of from 40/60 to 70/30.
Claim 6
Dependent Claim
24 words
A biaxially stretched film according to claim 2, wherein the ratio of ethylene to tetrafluoroethylene is in a range of from 40/60 to 70/30.
Claim 7
Dependent Claim
24 words
A biaxially stretched film according to claim 1, wherein the ratio of ethylene to tetrafluoroethylene is in a range of from 45/55 to 60/40.
Claim 8
Dependent Claim
24 words
A biaxially stretched film according to claim 2, wherein the ratio of ethylene to tetrafluoroethylene is in a range of from 45/55 to 60/40.
Claim 9
Dependent Claim
46 words
A biaxially stretched film according to claim 1 containing at least 90 mole % of ethylene-tetrafluoroethylene copolymer, and further containing a fluoroolefin other than tetrafluoroethylene in such an amount as to provide a total fluorine content in the range of from 40 to 75% by weight.
Claim 10
Dependent Claim
46 words
A biaxially stretched film according to claim 2 containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, and further containing a fluoroolefin other than tetrafluoroethylene in such an amount as to provide a total fluorine content in the range of from 40 to 75% by weight.
Claim 11
Dependent Claim
46 words
A biaxially stretched film according to claim 4 containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, and further containing a fluoroolefin other than tetrafluoroethylene in such an amount as to provide a total fluorine content in the range of from 40 to 75% by weight.
Claim 12
Dependent Claim
46 words
A biaxially stretched film according to claim 5 containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, and further containing a fluoroolefin other than tetrafluoroethylene in such an amount as to provide a total fluorine content in the range of from 40 to 75% by weight.
Claim 13
Dependent Claim
30 words
A biaxially stretched film according to claim 1, wherein the copolymer has a value of crystallization property ΔT of not less than 20° C. and not more than 55° C.
Claim 14
Dependent Claim
30 words
A biaxially stretched film according to claim 2, wherein the copolymer has a value of crystallization property ΔT of not less than 20° C. and not more than 55° C.
Claim 15
Dependent Claim
30 words
A biaxially stretched film according to claim 4, wherein the copolymer has a value of crystallization property ΔT of not less than 20° C. and not more than 55° C.
Claim 16
Dependent Claim
30 words
A biaxially stretched film according to claim 5, wherein the copolymer has a value of crystallization property ΔT of not less than 20° C. and not more than 55° C.
Claim 17
Dependent Claim
29 words
A biaxially stretched film according to claim 1, wherein the film is stretched to at least 2.5 times the original size in each of the longitudinal and lateral directions.
Claim 18
Dependent Claim
29 words
A biaxially stretched film according to claim 2, wherein the film is stretched to at least 2.5 times the original size in each of the longitudinal and lateral directions.
Claim 19
Dependent Claim
29 words
A biaxially stretched film according to claim 4, wherein the film is stretched to at least 2.5 times the original size in each of the longitudinal and lateral directions.
Claim 20
Dependent Claim
29 words
A biaxially stretched film according to claim 5, wherein the film is stretched to at least 2.5 times the original size in each of the longitudinal and lateral directions.
Claim 21
Independent Claim
194 words
A method for the manufacture of a stretched fluorine type film, comprising the steps of heating a thermoplastic resin containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, having a value of crystallization property, expressed by the equation ΔT=T.sub.m -T.sub.c wherein T m (melting point) stands for the peak melting temperature (°C.) found when a sample is heated at a temperature increase rate of 20° C./minute using differential scanning calorimeter (DSC), and T c (crystallizing temperature during fall of temperature) stands for the peak crystallizing temperature (°C.) found when the sample is cooled at a temperature decrease rate of 80° C./minute from the melting point plus 20° C. using said DSC, of not less than 15° C. and not more than 60° C., to form a molten resin; extruding the molten resin through a die; and cooling the extruded molten resin at a cooling speed of at least 70° C. in the range of the melting point minus 10° C. to the melting point minus 100° C. to thereby form a film while simultaneously biaxially stretching said film to at least two times the original size in each of the longitudinal and lateral directions.
Claim 22
Independent Claim
194 words
A method for the manufacture of a stretched fluorine type film, comprising the steps of heating a thermoplastic resin containing at least 90 mol % of ethylene-tetrafluoroethylene copolymer, having a value of crystallization property, expressed by the equation ΔT=T.sub.m -T.sub.c wherein T m (melting point) stands for the peak melting temperature (°C.) found when a sample is heated at a temperature increase rate of 20° C./minute using differential scanning calorimeter (DSC), and T c (crystallizing temperature during fall of temperature) stands for the peak crystallizing temperature (°C.) found when the sample is cooled at a temperature decrease rate of 80° C./minute from the melting point plus 20° C. using said DSC, of not less than 15° C. and not more than 60° C., to form a molten resin; extruding the molten resin through a die; and cooling the extruded molten resin at a cooling speed of at least 70° C. in the range of the melting point minus 10° C. to the melting point minus 100° C. to thereby form a film while simultaneously biaxially stretching said film to at least two times the original size in each of the longitudinal and lateral directions.
Claim 23
Dependent Claim
41 words
A biaxially stretched film according to claim 1, wherein the biaxially stretched film is heat set at a temperature exceeding 160° C. and not exceeding the melting point in a condition of limited shrinkage within 20%, increased length, or fixed length.
Claim 24
Dependent Claim
39 words
A method according to claim 20, wherein the biaxially stretched film is heat set at a temperature exceeding 160° C. and not exceeding the melting point in a condition of limited shrinkage within 20%, increased length, or fixed length.
References Cited (Backward Citations)
US3315020A
Cited
US3813461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |