US5298708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave-active tape having a cured polyolefin pressure-sensitive adhesive layer
Assignee: 3M Co
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Filing: 1991-02-07
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Granted: 1994-03-29
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Expires: 2011-02-07
Abstract
Abstract A piece of microwave-active tape which is odor-free and physiologically inert can be adhered to a food package and remains strongly adhered during cooking at temperatures of at least 200° C. The tape has layers of microwave-active material and a pressure-sensitive adhesive which is a polymeric α-olefin that has been cured to afford a "Peel Value" of at least 5 N/dm and a "Shrink Back" at 220° C. of less than 5%. The tape can have a flexible backing such as a low-adhesion carrier web which can be stripped off from a piece of the tape that has been applied to a microwave food package, or when the backing is heat-resistant, it can be left in place.
Inventors
- 👤 Gaddam N. Babu
- 👤 Susan S. Christopher
- 👤 Pierre H. LePere
- 👤 James R. Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:53
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/18; C08L23/20; B; B65; B65D; B65D81/00; B65D81/34; B65D81/3446; C09; C09J; C09J7/00; C09J7/20; C09J7/29; C09J7/30; C09J7/38; C09J7/381; B65D2581/00; B65D2581/34; B65D2581/3437; B65D2581/3439; B65D2581/3445; B65D2581/3463; B65D2581/3466; B65D2581/3471; B65D2581/3472; B65D2581/3477; B65D2581/3478; B65D2581/3486; B65D2581/3494; C09J2301/00; C09J2301/10; C09J2301/16; C09J2301/162; C09J2400/00; C09J2400/10; C09J2400/16; C09J2400/163; C09J2423/00; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/28; Y10T428/2852; Y10T428/2878
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
61 words
A food package comprising a piece of a microwave-active tape comprising layers of (a) an oriented backing material, (b) a microwave-active material, and (c) a pressure-sensitive adhesive, wherein said pressure-sensitive adhesive comprises a polymeric α-olefin that has been cured and has a "Peel" value of at least 5 N/dm and a "Shrink Back" value at 220° C. of less than 5%.
Claim 2
Dependent Claim
61 words
A food package comprising a piece of a microwave-active tape comprising layers of (a) an oriented backing material, (b) a microwave-active material, and (c) a pressure-sensitive adhesive, wherein said pressure-sensitive adhesive comprises a polymeric α-olefin that has been cured and has a "Peel" value of at least 5 N/dm and a "Shrink Back" value at 220° C. of less than 5%.
Claim 3
Dependent Claim
16 words
The food package as described in claim 1, wherein said microwave active tape provides automatic venting.
Claim 4
Dependent Claim
56 words
A microwave-active tape comprising in sequence: a) a backing material, b) a microwave active material layer, and c) a layer of pressure sensitive adhesive, wherein the pressure sensitive adhesive comprises a cured polymeric α-olefin and has a "Peel" value of at least 5 N/dm and a "Shrink Back" value at 220° C. of less than 5%.
Claim 5
Dependent Claim
56 words
A microwave-active tape comprising in sequence: a) a backing material, b) a microwave active material layer, and c) a layer of pressure sensitive adhesive, wherein the pressure sensitive adhesive comprises a cured polymeric α-olefin and has a "Peel" value of at least 5 N/dm and a "Shrink Back" value at 220° C. of less than 5%.
Claim 6
Dependent Claim
31 words
The microwave-active tape as described in claim 2, wherein said polymeric α-olefin is selected from a group consisting of radiation curable poly(α-olefin), thermally-curable hydrosiloxane poly(α-olefin), radiation-curable hydrosiloxane poly(α-olefin), and moisture-curable poly(α-olefin).
Claim 7
Dependent Claim
26 words
The microwave active tape as described in claim 4, wherein the radiation curable poly(α-olefin) has an inherent viscosity in the range of 4.0 to 9.0 dl/g.
Claim 8
Dependent Claim
26 words
The microwave active tape as described in claim 4, wherein the moisture curable poly(α-olefin) has an inherent viscosity in the range of 4.0 to 9.0 dl/g.
Claim 9
Dependent Claim
19 words
The microwave-active tape as described in claim 4, wherein said poly(α-olefin) is blended with at least one thermoplastic polymer.
Claim 10
Dependent Claim
21 words
The microwave-active tape as described in claim 2, wherein said microwave active material and pressure-sensitive adhesive are in separate, adjacent layers.
Claim 11
Dependent Claim
35 words
The microwave active tape as described in claim 3, wherein said backing material comprises a low-adhesion carrier web, which can be stripped off prior to applying the microwave active tape to a microwave food package.
Claim 12
Dependent Claim
18 words
The microwave active tape as described in claim 3, wherein said backing material comprises a heat-resistant polymeric substrate.
Claim 13
Dependent Claim
16 words
The microwave-active tape as described in claim 10, wherein said heat-resistant polymeric substrate is biaxially-oriented polypropylene.
Claim 14
Dependent Claim
17 words
The microwave-active tape as described in claim 10, wherein said heat-resistant polymeric substrate is biaxially-oriented poly(ethylene terephthalate).
Claim 15
Dependent Claim
15 words
The microwave-active tape as described in claim 10, wherein said heat-resistant polymeric substrate is poly(4-methylpent-1-ene).
Claim 16
Dependent Claim
21 words
The microwave active tape as described in claim 3, wherein said microwave active material layer converts microwave energy into sensible heat.
Claim 17
Dependent Claim
70 words
The microwave active tape as described in claim 14, wherein said microwave active material layer comprises at least one of (a) a thin metallized polymeric substrate, (b) a thin coating of conductive paint on a polymeric substrate, wherein said conductive paint comprises graphite, carbon black, or metallic particles or flakes, and (c) a thin coating of conductive particles in an organic binder, wherein said particles are carbon black or graphite.
Claim 18
Dependent Claim
18 words
The microwave active tape as described in claim 3, wherein said microwave active material layer reflects microwave energy.
Claim 19
Dependent Claim
41 words
The microwave active tape as described in claim 16, wherein said microwave active material comprises at least one of a metal foil having a thickness greater than 1 micrometer, and a metal mesh having openings greater than 2 mm in diameter.
Claim 20
Dependent Claim
37 words
The microwave active tape as described in claim 4, wherein the pressure sensitive adhesive is hot melt coatable when the inherent viscosity of the radiation curable poly α-olefin is in the range of 1.5 to 4.0 dl/g.
Claim 21
Dependent Claim
37 words
The microwave active tape as described in claim 4, wherein the pressure sensitive adhesive is hot melt coatable when the inherent viscosity of the moisture curable poly α-olefin is in the range of 1.5 to 4.0 dl/g.
Claim 22
Dependent Claim
27 words
The microwave active tape as described in claim 4, wherein the thermally curable poly α-olefin has an inherent viscosity in the range of 1.5 to 9.0 dl/g.
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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) | 1997-03-28 | 1997-09-27 | 1998-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-28 | 2001-09-27 | 2002-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-28 | 2005-09-27 | 2006-03-29 | $7700.00 | Window Closed / Lapsed |