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US4384024A
Expired / Lapsed
US
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Composite heat-sealable films
Assignee: Imperial Chemical Industries Ltd
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Filing: 1981-05-19
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Granted: 1983-05-17
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Expires: 2001-05-19
Abstract
Abstract A multiple-layer heat-sealable film comprising a polyolefin substrate layer having on at least one surface thereof a heat-sealable layer comprising a random copolymer of propylene with from greater than 4 to 10 wt% of ethylene, the copolymer having a degree of randomness of greater than 2.5.
Inventors
- 👤 Douglas L. Mitchell
- 👤 Robert C. Lansbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:58
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; C; C09; C09J; C09J123/00; C09J123/02; C09J123/10; C09J123/14; C09J123/142; C09J7/00; C09J7/20; C09J7/22; C09J7/30; C09J7/35; B29; B29K; B29K2995/00; B29K2995/0018; B29K2995/0022; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/50; B32B2307/514; B32B2307/518; B32B2323/00; B32B2323/04; B32B2323/10; B32B2439/00; B32B2439/70; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
100 words
A multiple-layer film comprising a polyolefin substrate layer having on at least one surface thereof a propylene-ethylene copolymer heat-sealable layer wherein the substrate layer comprises a polymer or copolymer of an alpha-olefin, the molecule of which contains from 2 to 6 carbon atoms, and wherein the heat-sealable surface layer on said at least one surface comprises a random copolymer of propylene with ethylene, the ethylene content of the copolymer being within a range of from greater than 4 up to 10% by weight of the copolymer and the heat-sealable propylene-ethylene copolymer having a degree of randomness of greater than 2.5.
Claim 2
Dependent Claim
100 words
A multiple-layer film comprising a polyolefin substrate layer having on at least one surface thereof a propylene-ethylene copolymer heat-sealable layer wherein the substrate layer comprises a polymer or copolymer of an alpha-olefin, the molecule of which contains from 2 to 6 carbon atoms, and wherein the heat-sealable surface layer on said at least one surface comprises a random copolymer of propylene with ethylene, the ethylene content of the copolymer being within a range of from greater than 4 up to 10% by weight of the copolymer and the heat-sealable propylene-ethylene copolymer having a degree of randomness of greater than 2.5.
Claim 3
Dependent Claim
15 words
A multiple-layer film according to claim 1 wherein the substrate layer comprises a propylene homopolymer.
Claim 4
Dependent Claim
33 words
A multiple-layer film according to claim 1 wherein the copolymer forming the at least one surface layer contains from 4.25 to 8.0 weight percent of ethylene based on the weight of the copolymer.
Claim 5
Dependent Claim
21 words
A multiple-layer film according to claim 1 wherein the degree of randomness of the propylene-ethylene copolymer is from 4.0 to 6.5.
Claim 6
Dependent Claim
22 words
A multiple-layer film according to claim 1 wherein the propylene-ethylene copolymer has a melt flow index of less than 75 g/10 minutes.
Claim 7
Dependent Claim
22 words
A multiple-layer film according to claim 1 wherein the propylene-ethylene copolymer has a principal melting temperature peak of less than 150° C.
Claim 8
Dependent Claim
19 words
A multiple-layer film according to claim 1 wherein the propylene-ethylene copolymer is produced by a gas phase copolymerisation process.
Claim 9
Dependent Claim
16 words
A multiple-layer film according to claim 1 wherein at least the substrate layer is biaxially oriented.
References Cited (Backward Citations)
JPS4914343A
Cited
GB1440317A
Cited
GB1532180A
Cited
EP0002606A1
Cited
JPS5514223A
Cited
US4294882A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |