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US4256784A
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Heat-sealable plastic film
Assignee: Hoechst AG
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Filing: 1977-08-22
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Granted: 1981-03-17
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Expires: 1997-08-22
Abstract
Abstract Disclosed is a heat-sealable film comprising a base film of a polymer or copolymer of an α-olefin having from 2 to 6 carbon atoms in the molecule and applied to at least one surface of the base film, a heat-sealable interpolymer layer comprising a terpolymer comprised of from about: 93.2-99.0 percent by weight of propylene units, 0.5-1.9 percent by weight of ethylene units, and 0.5-4.9 percent by weight of units of an α-olefin having from 4 to 10 carbon atoms in the molecule, and in which the comonomers are substantially statistically distributed. Also disclosed are a method for producing this film and a packaging method utilizing the film.
Inventors
- 👤 Dieter Gebhardt
- 👤 Siegfried Janocha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:09
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; C; C08; C08F; C08F210/00; C08F210/04; C08F210/06; B32B27/18; B32B27/20; B32B27/32; B32B27/327; C09; C09J; C09J123/00; C09J123/02; C09J123/10; C09J123/14; C09J123/142; B32B38/00; B32B38/0012; B32B2038/0028; B32B2250/00; B32B2250/02; B32B2250/24; B32B2250/242; B32B2307/00; B32B2307/20; B32B2307/21; B32B2307/30; B32B2307/31; B32B2307/40; B32B2307/402; B32B2307/4026; B32B2307/50; B32B2307/514; B32B2307/518; B32B2307/70; B32B2307/746; B32B2309/00; B32B2309/08; B32B2309/10; B32B2309/105; B32B2323/00; B32B2323/10; B32B2439/00; B32B2439/70; Y; Y10; Y10S; Y10S526/00; Y10S526/916; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31938
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
91 words
A heat-sealable film, comprising a base film of a polymer or copolymer of an α-olefin having from 2 to 6 carbon atoms in the molecule and applied to at least one surface of the base film, a heat-sealable interpolymer layer comprising a terpolymer comprised of from about 93.2-99.0 percent by weight of propylene units, 0.5-1.9 percent by weight of ethylene units, and 0.5-4.9 percent by weight of units of an α-olefin having from 4 to 10 carbon atoms in the molecule, and in which the comonomers are substantially statistically randomly distributed.
Claim 2
Dependent Claim
91 words
A heat-sealable film, comprising a base film of a polymer or copolymer of an α-olefin having from 2 to 6 carbon atoms in the molecule and applied to at least one surface of the base film, a heat-sealable interpolymer layer comprising a terpolymer comprised of from about 93.2-99.0 percent by weight of propylene units, 0.5-1.9 percent by weight of ethylene units, and 0.5-4.9 percent by weight of units of an α-olefin having from 4 to 10 carbon atoms in the molecule, and in which the comonomers are substantially statistically randomly distributed.
Claim 3
Dependent Claim
17 words
The film according to claim 1, wherein said α-olefin in the heat-sealable layer comprises 1-butene or 1-hexene.
Claim 4
Dependent Claim
28 words
The film according to claim 1, wherein prior to the formation of the heat-sealable layer, the terpolymer has an RSV value of from about 1.5 to 15.0 dl/g.
Claim 5
Dependent Claim
28 words
The film according to claim 3, wherein prior to the formation of the heat-sealable layer, the terpolymer has an RSV value of from about 2.0 and 10.0 dl/g.
Claim 6
Dependent Claim
23 words
The film according to claim 1, wherein the thickness of the heat-sealable layer is in the range from about 0.5 to 3.5 μm.
Claim 7
Dependent Claim
23 words
The film according to claim 5, wherein the thickness of the heat-sealable layer is in the range from about 1.0 and 2.0 μm.
Claim 8
Dependent Claim
17 words
The film according to claim 1, wherein the base film is stretched in at least one direction.
Claim 9
Dependent Claim
12 words
The film according to claim 7, wherein the base film is heat-set.
Claim 10
Dependent Claim
14 words
The film according to claim 1, wherein said film is in flat sheet form.
Claim 11
Dependent Claim
22 words
The film according to claim 1, wherein the base film has a thickness in the range from about 8 to 100 μm.
Claim 12
Dependent Claim
22 words
The film according to claim 1, wherein the base film has a thickness in the range from about 20 and 45 μm.
Claim 13
Dependent Claim
16 words
The film according to claim 1, wherein the base film comprises polypropylene or a propylene copolymer.
Claim 14
Dependent Claim
27 words
The film according to claim 1, wherein the heat-sealable layer and/or the base film further comprises an additive selected from antistatic agents, slip promotors, anti-oxidants, and dyestuffs.
Claim 15
Dependent Claim
29 words
The film according to claim 1, wherein both surfaces of the base film are coated with the heat-sealable layer and wherein said layers applied to the two surfaces differ.
Claim 16
Dependent Claim
13 words
The film according to claim 14, wherein said surface layers differ in thickness.
Claim 17
Dependent Claim
14 words
The film according to claim 14, wherein said surface layers differ in terpolymer composition.
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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) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |