Patent US4921749A successfully refreshed from Google Patents.
US4921749A
Expired / Lapsed
US
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Sealable films
Assignee: ExxonMobil Chemical Patents Inc
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Filing: 1987-05-29
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Granted: 1990-05-01
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Expires: 2007-05-29
Abstract
Abstract A film having superior seal strength and barrier properties comprises a base layer comprising 70 to 97 weight % of a polyolefin, e.g. polypropylene, and 3 to 30% weight of a resin of lower molecular weight than the polyolefin, e.g. a hydrogenated petroleum resin. On at least one of the surfaces of the base layer is a 1 to 20 weight % of a film of a random copolymer of 80 to 99 weight % of propylene and 1 to 20 weight % of ethylene, for example, an isotactic propylene-ethylene copolymer.
Inventors
- 👤 Bernard L. L. Bossaert
- 👤 Stefan B. Ohlsson
- 👤 William F. M. J. Willems
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:55
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/06; B32B27/08; B32B27/18; B32B2307/00; B32B2307/50; B32B2307/514; B32B2307/518; B32B2323/00; B32B2323/10; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31725; Y10T428/3175; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
83 words
A film comprising a base layer which comprises 70 to 97 weight % of a polyolefin and 3 to 30 weight % of a hydrogenated resin having a molecular weight lower than that of the polyolefin, said layer having on at least one surface thereof 1 to 20 weight % based on the weight of the base layer, of a one component film layer of a copolymer of 80 to 99 weight % of propylene and 1 to 20 weight % of ethylene.
Claim 2
Dependent Claim
83 words
A film comprising a base layer which comprises 70 to 97 weight % of a polyolefin and 3 to 30 weight % of a hydrogenated resin having a molecular weight lower than that of the polyolefin, said layer having on at least one surface thereof 1 to 20 weight % based on the weight of the base layer, of a one component film layer of a copolymer of 80 to 99 weight % of propylene and 1 to 20 weight % of ethylene.
Claim 3
Dependent Claim
29 words
A film according to claim 1 in which the base layer comprises 70 to 90 weight % of the polyolefin and 10 to 30 wt. % of the resin.
Claim 4
Dependent Claim
17 words
A film according to claim 1 or claim 2 in which the copolymer is a random copolymer.
Claim 5
Dependent Claim
29 words
A film according to claim 1 wherein the polyolefin in the base layer is a polymer of a mono alpha olefin containing 2 to 4 carbon atoms per molecule.
Claim 6
Dependent Claim
55 words
A film according to claim 4 wherein the polypropylene is an isotactic polypropylene with a density of from 0.86 to 0.92 g/cc measured at 23° C. according to ASTM D 1505 and a melt flow index of from 1 to 15 g/10 min as determined according to ASTM D1238 (conditions 230° C. and 2.16 kg).
Claim 7
Dependent Claim
19 words
A film according to claim 5 wherein the hydrogenated resin in the base layer is a hydrogenated petroleum resin.
Claim 8
Dependent Claim
41 words
A film according to claim 6 wherein the hydrogenated resin has been prepared by hydrogenating using a hydrogenation catalyst at a temperature of 200° to 330° C., a thermally polymerised steam cracked distillate fraction or a catalytically polymerised unsaturated hydrocarbon fraction.
Claim 9
Dependent Claim
25 words
A film according to claim 7 in which the hydrogenated resin has a softening point as measured by ASTM E28 of 100° to 140° C.
Claim 10
Dependent Claim
26 words
A film according to claim 1 wherein the base layer comprises 75 to 85 weight % of polyolefin and 15 to 25 weight % of resin.
Claim 11
Dependent Claim
35 words
A film according to claim 9 wherein the base layer has on each surface 1 to 10 weight percent based on the weight of the base layer of said film layer comprising said random copolymer.
Claim 12
Dependent Claim
26 words
A film according to claim 10 wherein the random copolymer comprises 94 to 98 weight percent of propylene and 2 to 6 weight percent of ethylene.
Claim 13
Dependent Claim
57 words
A film according to claim 11 wherein the random copolymer is an isotactic propylene-ethylene copolymer with a density of from 0.86 to 0.92 g/cc measured at 23° C. according to ASTM D 1505 and a melt flow index of from 2 to 15 g/10 min as determined according to ASTM D1238 (conditions 230° C. and 2.16 kg).
Claim 14
Dependent Claim
10 words
A film according to claim 12 which is biaxially orientated.
Claim 15
Dependent Claim
27 words
A film according to claim 13 which is 10 to 60 microns thick and wherein the thickness of each outer film layer is 0.05 to 2.5 microns.
References Cited (Backward Citations)
JPS52151636A
Cited
JPS4849835A
Cited
GB1563691A
Cited
US4230767A
Cited
GB2028168A
Cited
US4590125A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |