US4367312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-sealable packaging film producing a peelable seal
Assignee: Amcor Flexibles Transpac BVBA
•
Filing: 1980-08-07
•
Granted: 1983-01-04
•
Expires: 2000-08-07
Abstract
Abstract Heat-sealable packaging film producing a peelable seal, process for the preparation thereof and packages made therefrom or comprising such a film. This film produces such a seal on a wide range of packaging films, including polyester, polyvinyl chloride, polyamide and polyacrylonitrile films owing to: 1. its chemical composition which comprises: (a) 55 to 95% by weight of at least one ethylene polymer selected from polyethylene having a density of from 0.91 to 0.93 g/cm3 and an ethylene-vinyl acetate copolymer containing at most 10% by weight of vinyl acetate, (b) 5 to 30% by weight of polystyrene, and (c) 0 to 20% by weight of a thermoplastic, elastomeric styrene-butadiene-styrene or styrene-isoprene-styrene block copolymer, and 2. the fact that that face of the film which is intended to form the peelable seal, has a surface tension of from 35 to 50, preferably of 37 to 45 millinewtons per meter. The film is prepared by extrusion followed by a corona discharge pretreatment of said face.
Inventors
- 👤 Walter Bontinck
- 👤 Marc D'Hondt
- 👤 Roland Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:48
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/12; C08J7/123; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/06; C08L23/08; C08L23/0846; C08L23/0853; C08J2323/00; C08J2323/02; C08J2323/04; C08L2205/00; C08L2205/03; C08L25/00; C08L25/02; C08L25/04; C08L25/06; C08L53/00; C08L53/02; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31928
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
103 words
A heat sealable packaging film producing a peelable seal comprising polymer constituents consisting essentially of (a) 55 to 95% by weight of at least one ethylene polymer selected from polyethylene having a density of from 0.91 to 0.93 g/cm 3 and an ethylene-vinyl acetate copolymer containing at most 10% by weight of vinyl acetate, (b) 5 to 30% by weight of polystyrene, and (c) 5 to 20% by weight of a thermoplastic, elastomeric styrene-butadiene-styrene or styrene-isoprene-styrene block copolymer, the face of the film which is intended to form the peelable seal having a surface tension of from 35 to 50 millinewtons per meter.
Claim 2
Dependent Claim
103 words
A heat sealable packaging film producing a peelable seal comprising polymer constituents consisting essentially of (a) 55 to 95% by weight of at least one ethylene polymer selected from polyethylene having a density of from 0.91 to 0.93 g/cm 3 and an ethylene-vinyl acetate copolymer containing at most 10% by weight of vinyl acetate, (b) 5 to 30% by weight of polystyrene, and (c) 5 to 20% by weight of a thermoplastic, elastomeric styrene-butadiene-styrene or styrene-isoprene-styrene block copolymer, the face of the film which is intended to form the peelable seal having a surface tension of from 35 to 50 millinewtons per meter.
Claim 3
Dependent Claim
33 words
A packaging film according to claim 1, wherein the face of the film which is intended to form the peelable seal has a surface tension of from 37 to 45 millinewtons per meter.
Claim 4
Dependent Claim
51 words
A packaging film according to claim 1, wherein the amount of constituent (a) represents 65 to 85% by weight, the amount of constituent (b) represents 10 to 20% by weight and the amount of constituent (c) represents 5 to 15% by weight, based on the total weight of the polymers present.
Claim 5
Dependent Claim
44 words
A packaging film according to claim 1, which additionally contains up to 10% by weight of mineral fillers and up to about 5% by weight of adjuvants conventional for packaging films, based on the total weight of the polymer constituents (a), (b) and (c).
Claim 6
Dependent Claim
130 words
A process for the preparation of a heat sealable packaging film producing a peelable seal, which comprises extruding a composition comprising polymer constituents consisting essentially of (a) 55 to 95% by weight of at least one ethylene polymer selected from polyethylene having a density of from 0.91 to 0.93 g/cm 3 and an ethylene-vinyl acetate copolymer containing at most 10% by weight of vinyl acetate, (b) 5 to 30% by weight of polystyrene, and (c) 5 to 20% by weight of a thermoplastic, elastomeric styrene-butadiene-styrene or styrene-isoprene-styrene block polymer and subjecting that face of the extruded film which is intended to form the peelable seal to a corona discharge pretreatment with an intensity sufficient to confer to said face a surface tension of from 35 to 50 millinewtons per meter.
Claim 7
Dependent Claim
130 words
A process for the preparation of a heat sealable packaging film producing a peelable seal, which comprises extruding a composition comprising polymer constituents consisting essentially of (a) 55 to 95% by weight of at least one ethylene polymer selected from polyethylene having a density of from 0.91 to 0.93 g/cm 3 and an ethylene-vinyl acetate copolymer containing at most 10% by weight of vinyl acetate, (b) 5 to 30% by weight of polystyrene, and (c) 5 to 20% by weight of a thermoplastic, elastomeric styrene-butadiene-styrene or styrene-isoprene-styrene block polymer and subjecting that face of the extruded film which is intended to form the peelable seal to a corona discharge pretreatment with an intensity sufficient to confer to said face a surface tension of from 35 to 50 millinewtons per meter.
Claim 8
Dependent Claim
47 words
A process according to claim 5, wherein the face of the film which is intended to form the peelable seal is subjected to a corona discharge pretreatment with an intensity sufficient to confer to said face a surface tension of from 37 to 45 millinewtons per meter.
Claim 9
Dependent Claim
50 words
A process according to claim 5, wherein the amount of constituent (a) represents 65 to 85% by weight, the amount of constituent (b) represents 10 to 20% by weight and the amount of constituent (c) represents 5 to 15% by weight, based on the total weight of the polymers present.
Claim 10
Dependent Claim
48 words
A process according to claim 5, wherein the composition subjected to extrusion contains up to 10% by weight of mineral fillers and up to about 5% by weight of adjuvants conventional for packaging films, based on to the total weight of the polymer constituents (a), (b) and (c).
Claim 11
Dependent Claim
12 words
A package made from or comprising a film according to 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) | 1986-01-03 | 1986-07-05 | 1987-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-03 | 1990-07-05 | 1991-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-03 | 1994-07-05 | 1995-01-04 | $7700.00 | Window Closed / Lapsed |