Patent US4374883A successfully refreshed from Google Patents.
US4374883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure-sensitive adhesive tape
Assignee: 3M Co
•
Filing: 1981-10-15
•
Granted: 1983-02-22
•
Expires: 2001-10-15
Abstract
Abstract Normally tacky and pressure-sensitive adhesive tape, having a composite adhesive stratum made of 2 or more separate layers in which the tape synergistically exhibits properties superior to those of a tape made with either component layer alone. One layer is a polyurethane having some adhesive properties but lacking true pressure-sensitivity. The exposed surface of the stratum is a conventional pressure-sensitive adhesive. Numerical criteria are specified for each layer.
Inventors
- 👤 Louis E. Winslow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:10
CPC Classifications
C; C09; C09J; C09J7/00; C09J7/20; C09J2301/00; C09J2301/20; C09J2301/208; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S428/914; Y10T; Y10T428/00; Y10T428/14; Y10T428/1452; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24959; Y10T428/24983; Y10T428/28; Y10T428/2839; Y10T428/2848; Y10T428/31504; Y10T428/31551; Y10T428/31565; Y10T428/31591; Y10T428/31786
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
193 words
Normally tacky and pressure-sensitive adhesive tape having good holding power, resistance to aging and comparatively low cost comprising a sheet backing bearing a composite adhesive stratum comprising a layer of rubbery, compliant polyurethane, and, bonded over the polyurethane layer so as to constitute the outermost surface, a layer of soft, normally tacky and pressure-sensitive adhesive which is immiscible with the polyurethane, the thickness of the polyurethane layer being at least about twice the thickness of the pressure-sensitive adhesive layer, the polyurethane having a 10-second shear-creep compliance of at least 5×10 -6 cm 2 /dyne, a 7-10 minute shear rate viscosity of at least 10 6 Pa.s, a 7-10 minute delayed elastic compliance component greater than 50%, and an equilibrium elastic compliance greater than 90%, and the pressure-sensitive adhesive having a 10-second shear creep compliance component of at least 1.5×10 -6 cm 2 /dyne, a 7-10 minute shear rate viscosity of at least 3×10 6 Pa.s, and a 7-10 minute delayed elastic compliance component greater than 50%, said tape exhibiting superior adhesive properties to those attainable with tape in which the backing is coated with either the polyurethane alone or the pressure-sensitive adhesive alone.
Claim 2
Dependent Claim
193 words
Normally tacky and pressure-sensitive adhesive tape having good holding power, resistance to aging and comparatively low cost comprising a sheet backing bearing a composite adhesive stratum comprising a layer of rubbery, compliant polyurethane, and, bonded over the polyurethane layer so as to constitute the outermost surface, a layer of soft, normally tacky and pressure-sensitive adhesive which is immiscible with the polyurethane, the thickness of the polyurethane layer being at least about twice the thickness of the pressure-sensitive adhesive layer, the polyurethane having a 10-second shear-creep compliance of at least 5×10 -6 cm 2 /dyne, a 7-10 minute shear rate viscosity of at least 10 6 Pa.s, a 7-10 minute delayed elastic compliance component greater than 50%, and an equilibrium elastic compliance greater than 90%, and the pressure-sensitive adhesive having a 10-second shear creep compliance component of at least 1.5×10 -6 cm 2 /dyne, a 7-10 minute shear rate viscosity of at least 3×10 6 Pa.s, and a 7-10 minute delayed elastic compliance component greater than 50%, said tape exhibiting superior adhesive properties to those attainable with tape in which the backing is coated with either the polyurethane alone or the pressure-sensitive adhesive alone.
Claim 3
Dependent Claim
24 words
The tape of claim 1 wherein the thickness of the polyurethane layer is at least four times the thickness of each pressure-sensitive adhesive layer.
Claim 4
Dependent Claim
23 words
The tape of claim 1 or 2 wherein the polyurethane layer is in direct contact with and firmly bonded to the sheet backing.
Claim 5
Dependent Claim
22 words
The tape of claim 1 or 2 wherein a thin primer layer is interposed between the polyurethane layer and the pressure-sensitive adhesive.
Claim 6
Dependent Claim
51 words
The tape of claim 1 or 2 wherein (a) the sheet backing is a release liner and (b) a layer of soft, normally tacky and pressure-sensitive adhesive is interposed between the liner and the polyurethane layer, thereby providing a relatively inexpensive adhesive transfer tape having excellent holding power and shear properties.
Claim 7
Dependent Claim
15 words
The tape of claim 1 or 2 wherein the backing is a saturated crepe paper.
Claim 8
Dependent Claim
15 words
The tape of claim 1 or 2 wherein the backing is biaxially oriented polyethylene terephthalate.
References Cited (Backward Citations)
US997125A
Cited
US2652351A
Cited
US3161533A
Cited
US3340088A
Cited
US3811438A
Cited
US3812005A
Cited
US3885559A
Cited
US4112177A
Cited
US4260659A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |