US4619859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Highly-oriented stretchable multilayer film and process for producing the same
Assignee: Asahi Kasei Corp
•
Filing: 1984-09-25
•
Granted: 1986-10-28
•
Expires: 2004-09-25
Abstract
Abstract The present invention provides primarily an entirely new type multilayer oriented film suited for stretch wrapping, particularly for wrapping of foods. Its features include various excellent characteristics such as mechanical strength, transparency, heat resistance, sealability, stretchability, low temperature resistance, etc. In particular, the present invention concerns a process for producing such a multilayer film by cold stretching a multilayer containing at least one layer with a specific composition capable of a high degree of cold stretching, which enables simultaneously cold stretching of other layers made of resins which can be or cannot be stretched solely, through its cold stretching force, thereby imparting high strength to all the layers, and further applying a specific heat treatment on the stretched film to modify orientation of the film so as to increase stretchability and to stabilize dimension of the film.
Inventors
- 👤 Isao Yoshimura
- 👤 Hideo Hata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:54
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/18; B32B27/22; B32B27/32; B32B27/322; B32B2250/00; B32B2250/05; B32B2307/00; B32B2307/50; B32B2307/514; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928; Y10T428/31935
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
210 words
A multilayer oriented film excellent in sealability and stretchability, having high strength, high elongation and at least three layers comprising: (1) a base layer (M layer) containing primarily a specific mixed composition selected from the group of polymer compositions consisting of (A)+(B)+(C), (A)+(B) and (B)+(C); (A) being at least one ethylene type polymer selected from a low density polyethylene, a copolymer of ethylene with a monomer selected from the group consisting of a vinyl ester monomer, an aliphatic unsaturated mono-carboxylic acid, and an alkyl ester of said mono-carboxylic acid, and the derivatives of said copolymer; (B) being a soft elastomer having a Vicat softening point of 60° C. or lower; (C) being at least one polymer having a Vicat softening point of at least 100° C. selected from crystalline polypropylenes and crystalline polybutenes-1, at least one M layer being provided adjacent to a core layer; (2) an inside core layer (H layer) comprising primarily a polymer selected from (C); and (3) a surface layer (S layer) containing at least one polymer selected from polymer (A), soft elastomer (B), crystalline 1,2-polybutadiene and a soft ionomer resin from an ethylenic copolymer; said film having a stress on 100% elongation from 100 to 600 (g/cm-width) on average in the longitudinal and traverse directions.
Claim 2
Dependent Claim
210 words
A multilayer oriented film excellent in sealability and stretchability, having high strength, high elongation and at least three layers comprising: (1) a base layer (M layer) containing primarily a specific mixed composition selected from the group of polymer compositions consisting of (A)+(B)+(C), (A)+(B) and (B)+(C); (A) being at least one ethylene type polymer selected from a low density polyethylene, a copolymer of ethylene with a monomer selected from the group consisting of a vinyl ester monomer, an aliphatic unsaturated mono-carboxylic acid, and an alkyl ester of said mono-carboxylic acid, and the derivatives of said copolymer; (B) being a soft elastomer having a Vicat softening point of 60° C. or lower; (C) being at least one polymer having a Vicat softening point of at least 100° C. selected from crystalline polypropylenes and crystalline polybutenes-1, at least one M layer being provided adjacent to a core layer; (2) an inside core layer (H layer) comprising primarily a polymer selected from (C); and (3) a surface layer (S layer) containing at least one polymer selected from polymer (A), soft elastomer (B), crystalline 1,2-polybutadiene and a soft ionomer resin from an ethylenic copolymer; said film having a stress on 100% elongation from 100 to 600 (g/cm-width) on average in the longitudinal and traverse directions.
Claim 3
Dependent Claim
40 words
The multilayer oriented film according to claim 1, wherein the polymer (A) comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymers, ethylene-acrylate copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylate copolymers, ethylene-methacrylic acid copolymers and ethylenic copolymer ionomer resins.
Claim 4
Dependent Claim
43 words
The multilayer oriented film according to claim 1, wherein the soft elastomer (B) is a copolymer elastomer comprising 90 to 20 mole % of ethylene and at least one α-olefin selected from the group consisting of α-olefins having 3 to 12 carbon atoms.
Claim 5
Dependent Claim
34 words
The multilayer oriented film according to claim 1, wherein the soft elastomer (B) is a copolymer elastomer having a Vicat softening point of 50° C. or lower and a crystallinity of 30% or lower.
Claim 6
Dependent Claim
32 words
The multilayer oriented film according to claim 1, wherein the soft elastomer (B) is a copolymer further containing a small amount of a polyene copolymerized therein in addition to ethylene and α-olefin.
Claim 7
Dependent Claim
40 words
The multilayer oriented film according to claim 1, wherein the soft elastomer (B) is a thermoplastic copolymer elastomer having a melt index of 0.1 to 10 and the α-olefin in the soft elastomer (B) is selected from propylene and butene-1.
Claim 8
Dependent Claim
29 words
The multilayer oriented film according to claim 1, having a mixed composition with the ratios of respective components satisfying the following relationships: 0.9≧B/(A+B)≧0.05; or 0.90≧B/(B+C)≧0.30; or 0.90≧B/(A+B)≧0.05; and 2.0≧C/(A+B)≧0.05.
Claim 9
Dependent Claim
20 words
The multilayer oriented film according to claim 1, wherein the base layer (M layer) comprises a mixed composition of (A)+(B)+(C).
Claim 10
Dependent Claim
29 words
The multilayer oriented film according to claim 1, wherein the base layer (M layer) contains 1 to 30 wt. % of a carrier (AS agent) in addition to (A)+(B)+(C).
Claim 11
Dependent Claim
51 words
The multilayer oriented film according to claim 9, wherein the carrier (AS agent) is at least one selected from the group consisting of alicyclic saturated hydrocarbon resins, rosins, petroleum resins, terpene resins, cumarone resins or modified products thereof atactic polypropylenes (APP), 1,2-polybutadiene, and ethylene-vinyl acetate copolymers with high vinyl acetate content.
Claim 12
Dependent Claim
33 words
The multilayer oriented film according to claim 1, wherein the base layer contains at least one anti-fogging agent, plasticizer or mixtures there of in a total amount of 1 to 10 wt. %.
Claim 13
Dependent Claim
40 words
The multilayer oriented film according to claim 1, wherein the base layer (M layer) comprises 20 to 90%, the skin layer (S layer) 5 to 40% and the core layer (H layer) 5 to 40% of the total thickness, respectively.
Claim 14
Dependent Claim
21 words
The multilayer oriented film according to claim 1, having at least the layered structure of S layer/M layer/H layer/M layer/S layer.
Claim 15
Dependent Claim
21 words
The multilayer oriented film according to claim 1, having at least the layered structure of S layer/H layer/M layer/H layer/S layer.
Claim 16
Dependent Claim
27 words
The multilayer oriented film according to claim 1, having a stress on 200% elongation of 200 to 1,000 g/cm-width on average in the longitudinal and transverse directions.
Claim 17
Dependent Claim
26 words
The multilayer oriented film according to claim 1, wherein (A) is a copolymer of ethylene having a vinyl ester monomer and (C) is a crystalline polypropylene.
References Cited (Backward Citations)
US3375126A
Cited
US3579416A
Cited
US3847728A
Cited
US4082877A
Cited
CA1178415A
Cited
US4430378A
Cited
US4430377A
Cited
US4469752A
Cited
US4469753A
Cited
US4472228A
Cited
US4399181A
Cited
US4501634A
Cited
US4439478A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-27 | 1990-04-28 | 1990-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-27 | 1994-04-28 | 1994-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-27 | 1998-04-28 | 1998-10-28 | $7700.00 | Window Closed / Lapsed |