US5173357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tear-resistant polyester film and laminated sheets comprised of the same
Assignee: Polyplastics Co Ltd
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Filing: 1991-05-29
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Granted: 1992-12-22
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Expires: 2011-05-29
Abstract
Abstract Polyester film has a thickness of between 10 to 500 μm and exhibits excellent tear strength retention against thermal history conditions. The film is prepared from a resin composition which includes 100 parts by weight of a polyester consisting essentially of alkylene terephthalate groups as the main recurring units in the polymer chain and between 0.1 to 5 parts by weight of a bisoxazoline compound incorporated thereinto. The film is usefully employed as a sterilizing bag or as a food-packaging material and can be laminated to anther sheet of film or to paper.
Inventors
- 👤 Toshio Nakane
- 👤 Yukihiko Kageyama
- 👤 Kenji Hijikata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:08
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/10; B32B27/36; B32B7/00; B32B7/04; B32B7/12; C; C08; C08J; C08J5/00; C08J5/18; C08K; C08K5/00; C08K5/16; C08K5/34; C08K5/35; C08L; C08L67/00; C08L67/02; B32B2307/00; B32B2307/50; B32B2307/582; B32B2307/5825; B32B2317/00; B32B2317/12; B32B2367/00; B32B2439/00; B32B2439/70; C08J2367/00; C08J2367/02; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/268; Y10T428/269; Y10T428/31504; Y10T428/31786; Y10T428/3179
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
112 words
A polybutylene terephthalate film having a thickness of between 10 to 500 μm and exhibiting excellent tear-strength retention after being subjected to thermal history conditions, said film being formed of a resin composition which consists essentially of a blend of 100 parts by weight of a polybutylene terephthalate base resin and between 0.1 to 5 parts by weight of a bisoxazoline compound, and wherein said film has an initial tear strength value determined according to JIS P 8116 of at least 15 grams-force per 10 μm thickness of said film and a tear strength retention of at least 70% after being subjected to thermal history conditions of 120° C. for 3 minutes.
Claim 2
Dependent Claim
112 words
A polybutylene terephthalate film having a thickness of between 10 to 500 μm and exhibiting excellent tear-strength retention after being subjected to thermal history conditions, said film being formed of a resin composition which consists essentially of a blend of 100 parts by weight of a polybutylene terephthalate base resin and between 0.1 to 5 parts by weight of a bisoxazoline compound, and wherein said film has an initial tear strength value determined according to JIS P 8116 of at least 15 grams-force per 10 μm thickness of said film and a tear strength retention of at least 70% after being subjected to thermal history conditions of 120° C. for 3 minutes.
Claim 3
Dependent Claim
19 words
A polybutylene terephthalate film according to claim 1, wherein said polybutylene terephthalate base resin predominately includes 1,4-butylene terephthalate groups.
Claim 4
Dependent Claim
16 words
A polybutylene terephthalate film according to claim 1 or 2 wherein the bisoxazoline compound is phenylenebisoxazoline.
Claim 5
Dependent Claim
38 words
A polybutylene terephthalate film according to claim 3, wherein said resin composition further consists essentially of between 1 to 20 parts by weight of another thermoplastic resin per 100 parts by weight of the polybutylene terephthalate base resin.
Claim 6
Dependent Claim
127 words
A laminated paper composite sheet comprised of a paper sheet laminated to a polybutylene terephthalate film, wherein said film has a thickness of between 10 to 500 μm and exhibits excellent tear-strength retention after being subjected to thermal history conditions, said film being formed of a resin composition which consists essentially of a blend of 100 parts by weight of a polybutylene terephthalate base resin, and between 0.1 to 5 parts by weight of a bisoxazoline compound, and wherein said film has an initial tear strength value determined according to JIS P 8116 of at least 15 grams-force per 10 μm thickness of said film and a tear strength retention of at least 70% after being subjected to thermal history conditions of 120° C. for 3 minutes.
Claim 7
Dependent Claim
127 words
A laminated paper composite sheet comprised of a paper sheet laminated to a polybutylene terephthalate film, wherein said film has a thickness of between 10 to 500 μm and exhibits excellent tear-strength retention after being subjected to thermal history conditions, said film being formed of a resin composition which consists essentially of a blend of 100 parts by weight of a polybutylene terephthalate base resin, and between 0.1 to 5 parts by weight of a bisoxazoline compound, and wherein said film has an initial tear strength value determined according to JIS P 8116 of at least 15 grams-force per 10 μm thickness of said film and a tear strength retention of at least 70% after being subjected to thermal history conditions of 120° C. for 3 minutes.
Claim 8
Dependent Claim
23 words
A composite sheet as in claim 5, wherein said polybutylene terephthalate base resin of said polybutylene terephthalate film predominately includes 1,4-butylene terephthalate groups.
Claim 9
Dependent Claim
15 words
A composite sheet as in claim 5 or 6, wherein the bisoxazoline compound is phenylenebisoxazoline.
Claim 10
Dependent Claim
36 words
A composite sheet according to claim 7, wherein resin composition further consists essentially of between 1 to 20 parts by weight of another thermoplastic resin per 100 parts by weight of the polybutylene terephthalate base resin.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-12-22 | 1996-06-22 | 1996-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-22 | 2000-06-22 | 2000-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-22 | 2004-06-22 | 2004-12-22 | $7700.00 | Window Closed / Lapsed |