US4931327A
Expired / Lapsed
US
⏱️ 0.0 years remaining
White opaque opp film for tamper evident package
Assignee: Mobil Oil AS
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Filing: 1989-06-14
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Granted: 1990-06-05
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Expires: 2009-06-14
Abstract
Abstract A tamper-evident film includes a hydrocarbon polymer core layer (a) having an upper face and a lower face; an oriented tamper-evident layer applied to at least the lower face of core layer (a), layer (b) being fabricated from a mixture of a polyolefin and a filler of particles which induce cavitation upon orientation, layer (b) having an internal cohesiveness which is less than the internal cohesiveness and bonding strength of packaging adhesives and heat seals; and, an oriented skin layer (c) applied to the upper face of core layer (a) if layer (b) has not been applied thereon, layer (c) being hydrocarbon polymer. A tamper-evident package seal and package are also provided.
Inventors
- 👤 Leland L. Liu
- 👤 Michael T. Heffelfinger
- 👤 Donald G. Whyman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:52
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/18; B32B27/20; B32B27/32; B32B5/00; B32B5/16; B65; B65D; B65D65/00; B65D65/38; B32B2250/00; B32B2250/40; B32B2323/00; B32B2323/04; B32B2323/10; B32B2439/00; B32B2439/70; B65D2401/00; B65D2401/10; Y; Y10; Y10S; Y10S206/00; Y10S206/807; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1372; Y10T428/1376; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979; Y10T428/249981; Y10T428/249986; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
123 words
A tamper-evident film comprising: (a) an oriented polymer core layer having an upper face and a lower face; (b) an oriented tamper-evident layer applied to at least the lower face, but also optionally to the upper face of core layer (a), said layer (b) being fabricated from a mixture of a polyolefin and a filler which induces cavitation upon orientation, layer (b) having an internal cohesiveness which is less than the internal cohesiveness and bonding strength of packaging adhesives and heat seals; and (c) an oriented skin layer applied to the upper face of core layer (a) if layer (b) has not been applied thereon, said layer (c) being fabricated from a member of the group consisting of homopolymers, copolymers or blends thereof.
Claim 2
Dependent Claim
123 words
A tamper-evident film comprising: (a) an oriented polymer core layer having an upper face and a lower face; (b) an oriented tamper-evident layer applied to at least the lower face, but also optionally to the upper face of core layer (a), said layer (b) being fabricated from a mixture of a polyolefin and a filler which induces cavitation upon orientation, layer (b) having an internal cohesiveness which is less than the internal cohesiveness and bonding strength of packaging adhesives and heat seals; and (c) an oriented skin layer applied to the upper face of core layer (a) if layer (b) has not been applied thereon, said layer (c) being fabricated from a member of the group consisting of homopolymers, copolymers or blends thereof.
Claim 3
Dependent Claim
28 words
The film of claim 1 wherein said polymer of layer (a) is selected from the group consisting of polypropylene, polyethylene, ethylene copolymerized with alpha olefins and blends thereof.
Claim 4
Dependent Claim
22 words
The film of claim 1 wherein said layer (a) is fabricated from a polymer matrix material having a stratum of voids therein.
Claim 5
Dependent Claim
15 words
The film of claim 3 wherein said polymer matrix material of layer (a) is polypropylene.
Claim 6
Dependent Claim
42 words
The film of claim 3 wherein a substantial number of said voids within the polymer matrix material of layer (a) contains at least one void-initiating particle selected from the group consisting of polybutylene terephthalate and polyalphamethylstyrene, zinc oxide, zeospheres, and calcium carbonate.
Claim 7
Dependent Claim
26 words
The film of claim 1 wherein said polyolefin of layer (b) is selected from the group consisting of polyethylene, polypropylene, polybutylene, copolymers thereof, and blends thereof.
Claim 8
Dependent Claim
13 words
The film of claim 1 wherein said polyolefin of layer (b) is polypropylene.
Claim 9
Dependent Claim
15 words
The film of claim 1 wherein said filler of layer (b) is an organic material.
Claim 10
Dependent Claim
15 words
The film of claim 1 wherein said filler of layer (b) is an inorganic material.
Claim 11
Dependent Claim
31 words
The film of claim 1 wherein said filler of layer (b) is comprised of particles selected from the group consisting of calcium carbonate, zinc oxide, zeospheres, polybutylene terephthalate and polyalphamethyl styrene.
Claim 12
Dependent Claim
23 words
The film of claim 1 wherein said filler of layer (b) is present in amount from about 1 to about 20 weight percent.
Claim 13
Dependent Claim
23 words
The film of claim 1 wherein s id filler of layer (b) has a particle size of about 0.1 to about 10 microns.
Claim 14
Dependent Claim
23 words
The film of claim 1 wherein said filler of layer (b) is rigid particles which may or may not be identical in shape.
Claim 15
Dependent Claim
22 words
The film of claim 1 wherein the thickness of said layer (b) is from about 2% to about 90% of the film.
Claim 16
Dependent Claim
22 words
The film of claim 1 wherein the thickness of said layer (b) is from about 5% to about 20% of the film.
Claim 17
Dependent Claim
11 words
The film of claim 1 wherein said layer (c) is polypropylene.
Claim 18
Dependent Claim
10 words
The film of claim 1 wherein the layers are coextruded.
Claim 19
Dependent Claim
118 words
A tamper-evident package seal which comprises: (i) a first tamper-evident film as in claim 1 having an internal cohesive force and having an inner surface and an outer surface; (ii) a second film either identical to or different from the tamper-evident film as in claim 1; and (iii) at least one adhesive or heat sealant effective to bond said inner surface of first film (i) to said inner surface of the second film (ii), said adhesive or heat sealant having both a seal internal cohesion and an affinity for bonded surfaces which are greater than said film internal cohesive forces, whereby a force applied to separate said films results in rupture of at least one of said films.
Claim 20
Dependent Claim
11 words
A tamper-evident package made using the tamper-evident seal of claim 18.
Claim 21
Dependent Claim
11 words
The tamper-evident package of claim 19 sealed with a heat seal.
Claim 22
Dependent Claim
11 words
The tamper-evident package of claim 20 sealed with a cold seal.
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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) | 1993-06-04 | 1993-12-04 | 1994-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-04 | 1997-12-04 | 1998-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-04 | 2001-12-04 | 2002-06-05 | $7700.00 | Window Closed / Lapsed |