US4935273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure-activated innerseals and containers using same
Assignee: Unipac Corp
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Filing: 1989-02-01
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Granted: 1990-06-19
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Expires: 2009-02-01
Abstract
Abstract Closure liner, i.e., innerseal, comprising a pressure-activated adhesive that is a copolymer of butadiene and acrylonitrile or methacrylonitrile. The copolymer has a single glass transition temperature of no higher than about -25° C., a nitrile content of no greater than about 31% by weight, preferably of from about 18% by weight to about 30% by weight, a Mooney viscosity of at least 95 (measured according to ASTM D1646-87 at 100° C. for 4 minutes), preferably from about 120 to about 150. The copolymer is not cross-linked, and the amount of vinyl groups in the copolymer should not exceed 10% by weight.
Inventors
- 👤 David T. Ou-Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:19
CPC Classifications
B; B65; B65D; B65D41/00; B65D41/02; B65D41/04; B65D41/0435; B65D41/045; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1397; Y10T428/28; Y10T428/2848; Y10T428/2852; Y10T428/2878; Y10T428/2887; Y10T428/31504; Y10T428/31855; Y10T428/3188; Y10T428/31895; Y10T428/31906; Y10T428/31931; Y10T428/31935
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
101 words
A pressure-activated innerseal comprising a substrate bearing on at least one major surface thereof a layer of an adhesive composition comprising an amorphous butadiene-nitrile random copolymer having a single glass transition temperature no higher than about -25° C., a nitrile content no higher than about 31% by weight, a Mooney viscosity of at least 95 (measured according to ASTM D1646-87 at 100° C. for 4 minutes), a vinyl content of no greater than 10% by weight, said composition being substantially free of cross-links, provided that said composition is free of any additive that provides more than little or no finger tack.
Claim 2
Dependent Claim
101 words
A pressure-activated innerseal comprising a substrate bearing on at least one major surface thereof a layer of an adhesive composition comprising an amorphous butadiene-nitrile random copolymer having a single glass transition temperature no higher than about -25° C., a nitrile content no higher than about 31% by weight, a Mooney viscosity of at least 95 (measured according to ASTM D1646-87 at 100° C. for 4 minutes), a vinyl content of no greater than 10% by weight, said composition being substantially free of cross-links, provided that said composition is free of any additive that provides more than little or no finger tack.
Claim 3
Dependent Claim
20 words
The innerseal of claim 1, wherein the nitrile content is from about 18% by weight to about 30% by weight.
Claim 4
Dependent Claim
16 words
The innerseal of claim 1, wherein the Mooney viscosity is from about 120 to about 150.
Claim 5
Dependent Claim
11 words
The innerseal of claim 1, wherein the nitrile moiety is acrylonitrile.
Claim 6
Dependent Claim
11 words
The innerseal of claim 1, wherein the nitrile moiety is methacrylonitrile.
Claim 7
Dependent Claim
27 words
A container comprising the innerseal of claim 1, wherein the portion of the container in contact with the innerseal is formed from a material having high polarity.
Claim 8
Dependent Claim
14 words
The container of claim 6, wherein said high polarity material is a polymeric material.
Claim 9
Dependent Claim
30 words
The container of claim 7, wherein said polymeric material is selected from the group consisting of polyvinyl chloride, polyester, polycarbonate, polyvinylidene chloride, polystyrene, nitrile rubber, and derivatives of nitrile rubber.
Claim 10
Dependent Claim
130 words
A pressure-activated innerseal comprising from top to bottom: (a) a first film made of paper or polymeric material; (b) a layer of adhesive formed from thermoplastic or thermosetting plastic or rubber; (c) a second film made of paper or polymeric material; and (d) a layer of an adhesive composition comprising an amorphous butadiene-nitrile random copolymer having a single glass transition temperature no higher than about -25° C., a nitrile content no higher than about 31% by weight, a Mooney viscosity of at least 95 (measured according to ASTM D1646-87 at 100° C. for 4 minutes), a vinyl content of no greater than 10% by weight, said composition being substantially free of cross-links, provided that said composition is free of any additive that provides more than little or no finger tack.
Claim 11
Dependent Claim
130 words
A pressure-activated innerseal comprising from top to bottom: (a) a first film made of paper or polymeric material; (b) a layer of adhesive formed from thermoplastic or thermosetting plastic or rubber; (c) a second film made of paper or polymeric material; and (d) a layer of an adhesive composition comprising an amorphous butadiene-nitrile random copolymer having a single glass transition temperature no higher than about -25° C., a nitrile content no higher than about 31% by weight, a Mooney viscosity of at least 95 (measured according to ASTM D1646-87 at 100° C. for 4 minutes), a vinyl content of no greater than 10% by weight, said composition being substantially free of cross-links, provided that said composition is free of any additive that provides more than little or no finger tack.
Claim 12
Dependent Claim
15 words
The innerseal of claim 9, wherein the adhesive of layer (b) is a pressure-sensitive adhesive.
Claim 13
Dependent Claim
20 words
The innerseal of claim 9, wherein the nitrile content is from about 18% by weight to about 30% by weight.
Claim 14
Dependent Claim
16 words
The innerseal of claim 9, wherein the Mooney viscosity is from about 120 to about 150.
Claim 15
Dependent Claim
11 words
The innerseal of claim 9, wherein the nitrile moiety is acrylonitrile.
Claim 16
Dependent Claim
11 words
The innerseal of claim 9, wherein the nitrile moiety is methacrylonitrile.
Claim 17
Dependent Claim
27 words
A container comprising the innerseal of claim 9, wherein the portion of the container in contact with the innerseal is formed from a material having high polarity.
Claim 18
Dependent Claim
14 words
The container of claim 15, wherein said high polarity material is a polymeric material.
Claim 19
Dependent Claim
30 words
The container of claim 16, wherein said polymeric material is selected from the group consisting of polyvinyl chloride, polyester, polycarbonate, polyvinylidene chloride, polystyrene, nitrile rubber, and derivatives of nitrile rubber.
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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) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |