US4740400A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tinted heat-shrinkable multilayer films comprising a vinylidene chloride-vinyl chloride copolymer
Assignee: Viskase Corp
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Filing: 1986-03-27
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Granted: 1988-04-26
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Expires: 2006-03-27
Abstract
Abstract A transparent heat shrinkable, multilayer film comprising: (a) at least one layer comprising a vinylidene chloride-vinyl chloride copolymer; and (b) at least one layer comprising a thermoplastic polymer; and (c) a sufficient amount of a dioxazine violet pigment to provide a film which retains an aesthetically acceptable violet appearance despite exposure to elevated temperatures and/or irradiation.
Inventors
- 👤 Stanley Lustig
- 👤 Stephen J. Vicik
- 👤 John A. Ransford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:50
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/30; B32B27/06; B32B27/08; B32B27/16; B32B27/18; B32B27/20; B32B27/304; B32B2307/00; B32B2307/40; B32B2307/402; B32B2307/412; B32B2307/70; B32B2307/732; B32B2307/734; B32B2307/736; B32B2439/00; B32B2439/40; B32B2439/46; B32B2439/70; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/25; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
62 words
A transparent, heat shrinkable multilayer film comprising: (a) at least one layer comprising a vinylidene chloride-vinyl chloride copolymer; (b) at least one layer comprising a thermoplastic polymer; and (c) a sufficient amount of a dioxazine violet pigment to provide the film with a violet tint after said film is maintained at a temperature of 120° F. for a period of 3 days.
Claim 2
Dependent Claim
62 words
A transparent, heat shrinkable multilayer film comprising: (a) at least one layer comprising a vinylidene chloride-vinyl chloride copolymer; (b) at least one layer comprising a thermoplastic polymer; and (c) a sufficient amount of a dioxazine violet pigment to provide the film with a violet tint after said film is maintained at a temperature of 120° F. for a period of 3 days.
Claim 3
Dependent Claim
31 words
A transparent, heat shrinkable multilayer film in accordance with claim 1 wherein said vinylidene chloride-vinyl chloride copolymer layer has been irradiated to a dosage level of at least about one megarad.
Claim 4
Dependent Claim
97 words
A transparent, heat shrinkable multi-layer film comprising: (a) at least one layer comprising a vinylidene chloride-vinyl chloride copolymer said layer being visually perceived as yellow absent pigmentation thereof; (b) at least one layer comprising a thermoplastic polymer; and (c) a sufficient amount of a dioxazine violet pigment to provide the film with a Hunter L-Value within a range of from about 80 to about 90, a Hunter a-Value within a range of from about +0.25 to about +6, and a Hunter b-Value within a range of from about -0.25 to about -7, as per the Tristimulus Test.
Claim 5
Dependent Claim
97 words
A transparent, heat shrinkable multi-layer film comprising: (a) at least one layer comprising a vinylidene chloride-vinyl chloride copolymer said layer being visually perceived as yellow absent pigmentation thereof; (b) at least one layer comprising a thermoplastic polymer; and (c) a sufficient amount of a dioxazine violet pigment to provide the film with a Hunter L-Value within a range of from about 80 to about 90, a Hunter a-Value within a range of from about +0.25 to about +6, and a Hunter b-Value within a range of from about -0.25 to about -7, as per the Tristimulus Test.
Claim 6
Dependent Claim
89 words
A transparent, heat shrinkable multilayer film comprising: (a) at least one irradiated layer comprising a vinylidene chloride-vinyl chloride copolymer; and (b) at least one layer comprising a thermoplastic polymer; and (c) a sufficient amount of a dioxazine violet pigment to provide the film with a Hunter L-Value in a range of from about 80 to about 90, a Hunter a-Value in a range of from about +0.25 to about +6, and a Hunter b-Value in a range of from about -0.25 to about -7, as per the Tristimulus Test.
Claim 7
Dependent Claim
89 words
A transparent, heat shrinkable multilayer film comprising: (a) at least one irradiated layer comprising a vinylidene chloride-vinyl chloride copolymer; and (b) at least one layer comprising a thermoplastic polymer; and (c) a sufficient amount of a dioxazine violet pigment to provide the film with a Hunter L-Value in a range of from about 80 to about 90, a Hunter a-Value in a range of from about +0.25 to about +6, and a Hunter b-Value in a range of from about -0.25 to about -7, as per the Tristimulus Test.
Claim 8
Dependent Claim
25 words
A transparent, heat shrinkable multilayer film in accordance with claim 1, wherein said dioxazine violet pigment is a carbazole dioxazine violet of the formula: ##STR4##
Claim 9
Dependent Claim
35 words
A transparent, heat shrinkable multilayer film in accordance with claims 3 and 4 wherein said vinylidene chloride-vinyl chloride copolymer layer has been irradiated to a dosage level between about 3 megarads and about 5 megarads.
Claim 10
Dependent Claim
43 words
A transparent, heat shrinkable multilayer film in accordance with claim 1 wherein said pigment is present in said film an amount of from about 0.01 to about 0.04 percent by weight based on the total weight of vinylidene chloride-vinyl chloride copolymer present therein.
Claim 11
Dependent Claim
38 words
A transparent, heat shrinkable multilayer film in accordance with claim 1, wherein said vinylidene chloride-vinyl chloride copolymer has a vinylidene chloride content of from about 70 to about 95 weight percent, based on the weight of the copolymer.
Claim 12
Dependent Claim
23 words
A transparent, heat shrinkable multilayer film in accordance with claims 1, 3 and 4 wherein said thermoplastic polymer comprises an ethylene-vinyl acetate copolymer.
Claim 13
Dependent Claim
63 words
A transparent, heat shrinkable multilayer film in accordance with claim 1 wherein said violet tint is described by a Hunter L-Value within a range of from about 80 to about 90, a Hunter a-Value within a range of from about +0.25 to about +6, and a Hunter b-Value within a range of from about -0.25 to about -7, as per the Tristimulus Test.
Claim 14
Dependent Claim
64 words
A transparent, heat shrinkable multilayer film which comprises: (a) a layer comprising a vinylidene chloride-vinyl chloride copolymer irradiated to a dosage level of at least about 1 megarad; (b) at least one layer comprising a thermoplastic polymer; and (c) from about 0.01 to about 0.04 percent by weight, based on the total weight of the vinylidene chloride-vinyl chloride copolymer, of a carbazole dioxazine pigment.
Claim 15
Dependent Claim
64 words
A transparent, heat shrinkable multilayer film which comprises: (a) a layer comprising a vinylidene chloride-vinyl chloride copolymer irradiated to a dosage level of at least about 1 megarad; (b) at least one layer comprising a thermoplastic polymer; and (c) from about 0.01 to about 0.04 percent by weight, based on the total weight of the vinylidene chloride-vinyl chloride copolymer, of a carbazole dioxazine pigment.
Claim 16
Dependent Claim
43 words
A transparent, heat shrinkable multilayer film in accordance with claim 11 wherein the carbazole dioxazine pigment is of the formula: ##STR5## and the vinylidene chloride-vinyl chloride copolymer layer has been irradiated to a dosage level between about 3 megarads and about 5 megarads.
Claim 17
Dependent Claim
70 words
A transparent, heat shrinkable multilayer film in accordance with claim 4 wherein said film retains a Hunter L-Value within a range of from about 80 to about 90, a Hunter a-Value within a range of from about +0.25 to about +6, and a Hunter b-Value within a range of from about -0.25 to about -7 after being maintained at a temperature of 120° F. for a period of 3 days.
Claim 18
Dependent Claim
16 words
A bag suitable for use in meat packaging applications formed from the film of claim 1.
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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) | 1991-04-26 | 1991-10-26 | 1992-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-26 | 1995-10-26 | 1996-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-26 | 1999-10-26 | 2000-04-26 | $7700.00 | Window Closed / Lapsed |