US4243724A
Expired / Lapsed
US
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Thermoplastic multi-layer film
Assignee: Hoechst AG
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Filing: 1978-05-26
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Granted: 1981-01-06
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Expires: 1998-05-26
Abstract
Abstract Disclosed is a multi-layer film having two or more layers, comprising at least one first layer of a polymer comprising a linear polyamide, and at least one second layer of a polymer comprising a linear polyamide containing from about 2 to 40 percent by weight of a hydrophilic substance compatible with the polyamide, such as polyvinyl alcohol.
Inventors
- 👤 Hans Strutzel
- 👤 Klaus Hoheisel
- 👤 Siegfried Janocha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:22
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/34; B32B27/06; B32B27/08; B32B27/30; B32B27/306; B32B27/32; B32B2270/00; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/50; B32B2307/514; B32B2307/516; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/7244; B32B2307/7246; B32B2307/7248; B32B2307/728; B32B2307/738; B32B2323/00; B32B2323/04; B32B2323/046; B32B2329/00; B32B2329/04; B32B2377/00; B32B2439/00; B32B2553/00; Y; Y10; Y10S; Y10S138/00; Y10S138/07; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31725; Y10T428/31728
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
66 words
A multi-layer film having two or more layers, comprising at least one first layer of a polymer comprising a linear polyamide, and, adjacent to said first layer, at least one second layer of a polymer comprising a major portion of a linear polyamide containing from about 2 to 40 percent by weight of a hydrophilic substance compatible with the polyamide, said hydrophilic substance comprising polyvinyl alcohol.
Claim 2
Dependent Claim
66 words
A multi-layer film having two or more layers, comprising at least one first layer of a polymer comprising a linear polyamide, and, adjacent to said first layer, at least one second layer of a polymer comprising a major portion of a linear polyamide containing from about 2 to 40 percent by weight of a hydrophilic substance compatible with the polyamide, said hydrophilic substance comprising polyvinyl alcohol.
Claim 3
Dependent Claim
27 words
A multi-layer film according to claim 1, wherein the polyvinyl alcohol is comprised of a partially saponified form including less than 15 percent of unsaponified ester groups.
Claim 4
Dependent Claim
26 words
A multi-layer film according to claim 1, wherein the polyamide containing the hydrophilic substance comprises a polyamide having 4 to 6 carbon atoms in each unit.
Claim 5
Dependent Claim
17 words
A multi-layer film according to claim 3, wherein the polyamide containing the hydrophilic substance comprises polyamide 6.
Claim 6
Dependent Claim
30 words
A multi-layer film according to claim 1, having a permeability to oxygen of less than about 25 cm 3 /m 2 ·d ·bar, at a calculated thickness of 40 μm.
Claim 7
Dependent Claim
29 words
A multi-layer film according to claim 1, having a permeability to water vapor of less than about 50 g/m 2 ·d , at a calculated thickness of 40 μm.
Claim 8
Dependent Claim
36 words
A multi-layer film according to claim 1, wherein the first polyamide layer is bonded to the second polyamide layer containing the hydrophilic substance and comprises a polyamide having 9 to 12 carbon atoms in each unit.
Claim 9
Dependent Claim
20 words
A multi-layer film according to claim 7, wherein the polyamide of said first layer comprises polyamide 11 or polyamide 12.
Claim 10
Dependent Claim
30 words
A multi-layer film according to claim 1, wherein the first polyamide layer contacts the second polyamide film containing the hydrophilic substance and comprises a polymer blend of polyamide and polyethylene.
Claim 11
Dependent Claim
33 words
A multi-layer film according to claim 9, wherein said polymer blend comprises from about 25 to 75 percent by weight of polyamide and from about 75 to 25 percent by weight of polyethylene.
Claim 12
Dependent Claim
33 words
A multi-layer film according to claim 10, wherein said polymer blend comprises from about 40 to 60 percent by weight of polyamide and from about 60 to 40 percent by weight of polyethylene.
Claim 13
Dependent Claim
16 words
A multi-layer film according to claim 9, wherein said polymer blend comprises polyamide 6 and polyethylene.
Claim 14
Dependent Claim
18 words
A multi-layer film according to claim 9, wherein said polymer blend comprises polyamide 6 and a low-density polyethylene.
Claim 15
Dependent Claim
21 words
A multi-layer film according to claim 1, further comprising at least one additional layer of a thermoplastic polymer containing no polyamide.
Claim 16
Dependent Claim
16 words
A multi-layer film according to claim 14, wherein said additional layer is at least uniaxially stretched.
Claim 17
Dependent Claim
14 words
A multi-layer film according to claim 14, wherein said additional layer is heat set.
Claim 18
Dependent Claim
21 words
A multi-layer film according to claim 14, wherein said additional layer forms the outer layer and comprises a heat sealable polymer.
Claim 19
Dependent Claim
17 words
A multi-layer film according to claim 1, wherein said film is oriented in at least one direction.
Claim 20
Dependent Claim
13 words
A multi-layer film according to claim 1, wherein said film is heat set.
Claim 21
Dependent Claim
18 words
A package, comprising an article to be packaged enclosed within a multi-layer film as defined by claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |