Patent US5066098A successfully refreshed from Google Patents.
US5066098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cellular encapsulated-lens high whiteness retroreflective sheeting with flexible cover sheet
Assignee: 3M Co
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Filing: 1991-02-19
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Granted: 1991-11-19
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Expires: 2011-02-19
Abstract
Abstract Cellular, encapsulated-lens retroreflective sheeting comprising: (1) a base sheet of a monolayer of retroreflective elements partially embedded in a binder layer which typically is white or comprises a whitening agent; (2) a cover sheet disposed in spaced relation from the layer of retroreflective elements; and (3) a network of narrow intersecting bonds or seal legs that extend between the cover sheet and the base sheet and comprise binder material thermoformed at the point of contact between the base sheet and cover sheet so as to adhere the base sheet and the cover sheet together and form a plurality of cells within which retroreflective elements are hermetically sealed; wherein the cover sheet comprises an inner layer and at least a structural layer, the structural layer being adhered to the outside surface of the inner layer. The inner layer of the cover sheet has a higher Vicat Softening Point and/or lower adhesion to the microlenses than at least the structural layer of the cover sheet so that when the cover sheet and base sheet are sealed together and the binder material is thermoformed into contact with the cover sheet to form the seal legs, the binder material is better able to flow around and flood the front surfaces of the retroreflective lenses, thereby hiding same and imparting greater whiteness to the resultant sheeting.
Inventors
- 👤 Roger R. Kult
- 👤 Terry R. Bailey
- 👤 Howard R. Tolliver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:41
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/12; G02B5/126; G02B5/128
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
235 words
A cellular, encapsulated-lens retroreflective sheeting comprising: (1) a base sheet that comprises a monolayer of retroreflective elements partially embedded in a binder layer; (2) a cover sheet disposed in spaced relation from the layer of retroreflective elements; and (3) a network of narrow intersecting bonds that extend between said cover sheet and said base sheet and comprise binder material thermoformed at the point of contact between said bonds and said cover sheet so as to adhere said base sheet and said cover sheet together and from a plurality of cells within which retroreflective elements are hermetically sealed; wherein the cover sheet comprises an inner layer and at least a structural layer, said inner layer having an inside major surface that is in adherent contact with said intersecting bonds, and an outside major surface adhered to said structural layer of said cover sheet, and said inner layer having a Vicat Softening point of at least said structural layer of said cover sheet, said Vicat Softening Point of said inner layer also being higher than the minimum temperature at which said binder material was thermoformable into contact with said cover sheet, such that said inner layer improved the interaction between said cover sheet and said retroreflective elements so that when said binder material was thermoformed into contact with said cover sheet the flow of said binder material around the front surfaces of said retroreflective elements was improved.
Claim 2
Dependent Claim
235 words
A cellular, encapsulated-lens retroreflective sheeting comprising: (1) a base sheet that comprises a monolayer of retroreflective elements partially embedded in a binder layer; (2) a cover sheet disposed in spaced relation from the layer of retroreflective elements; and (3) a network of narrow intersecting bonds that extend between said cover sheet and said base sheet and comprise binder material thermoformed at the point of contact between said bonds and said cover sheet so as to adhere said base sheet and said cover sheet together and from a plurality of cells within which retroreflective elements are hermetically sealed; wherein the cover sheet comprises an inner layer and at least a structural layer, said inner layer having an inside major surface that is in adherent contact with said intersecting bonds, and an outside major surface adhered to said structural layer of said cover sheet, and said inner layer having a Vicat Softening point of at least said structural layer of said cover sheet, said Vicat Softening Point of said inner layer also being higher than the minimum temperature at which said binder material was thermoformable into contact with said cover sheet, such that said inner layer improved the interaction between said cover sheet and said retroreflective elements so that when said binder material was thermoformed into contact with said cover sheet the flow of said binder material around the front surfaces of said retroreflective elements was improved.
Claim 3
Dependent Claim
19 words
The sheeting of claim 1 wherein said Vicat Softening Point of said inner layer is at least 175° F.
Claim 4
Dependent Claim
19 words
The sheeting of claim 1 wherein said Vicat Softening Point of said inner layer is at least 200° F.
Claim 5
Dependent Claim
19 words
The sheeting of claim 1 wherein said Vicat Softening Point of said inner layer is at least 250° F.
Claim 6
Dependent Claim
29 words
The sheeting of claim 1 wherein said Vicat Softening Point of said inner layer is at least 15° F. higher than said Vicat Softening Point of said structural layer.
Claim 7
Dependent Claim
29 words
The sheeting of claim 1 wherein said Vicat Softening Point of said inner layer is at least 35° F. higher than said Vicat Softening Point of said structural layer.
Claim 8
Dependent Claim
24 words
The sheeting of claim 1 wherein said inner layer has a lower adhesion to glass than the adhesion to glass of said structural layer.
Claim 9
Dependent Claim
23 words
The sheeting of claim 1 wherein said retroreflective elements are microspheres and said sheeting further comprises a specularly reflecting layer underlying said microspheres.
Claim 10
Dependent Claim
11 words
The sheeting of claim 1 wherein said inner layer is colored.
Claim 11
Dependent Claim
11 words
The sheeting of claim 1 wherein said structural layer is colored.
Claim 12
Dependent Claim
11 words
The sheeting of claim 1 wherein said retroreflective elements comprise glass.
Claim 13
Dependent Claim
13 words
The sheeting of claim 1 wherein said binder layer comprises a whitening agent.
Claim 14
Dependent Claim
12 words
The sheeting of claim 12 wherein said whitening agent comprises a pigment.
Claim 15
Dependent Claim
11 words
The sheeting of claim 13 wherein said pigment comprises titanium dioxide.
Claim 16
Dependent Claim
25 words
The sheeting of claim 1 wherein said inside major surface of said inner layer is primed to improve the adhesion of said binder material thereto.
Claim 17
Dependent Claim
17 words
The sheeting of claim 1 wherein said sheeting has an overall CAP Y of at least 27.
Claim 18
Dependent Claim
24 words
The sheeting of claim 16 wherein said seal legs constitute between about 20 and 30 percent of the total surface area of said sheeting.
Claim 19
Dependent Claim
24 words
The sheeting of claim 1 wherein said inner layer of said cover sheet has a thickness of between about 0.05 mil and 3 mils.
Claim 20
Dependent Claim
22 words
The sheeting of claim 1 wherein said inner layer of said cover sheet has a thickness of less than about 2 mils.
Claim 21
Dependent Claim
21 words
The sheeting of claim 1 wherein said cover sheet has a total thickness of between about 1 mil and 10 mils.
Claim 22
Dependent Claim
20 words
The sheeting of claim 1 wherein said cover sheet has a total thickness of between about 2 and 4 mils.
Claim 23
Dependent Claim
21 words
The sheeting of claim 1 wherein said structural layer constitutes at least 50 percent of the thickness of said cover sheet.
Claim 24
Dependent Claim
20 words
The sheeting of claim 1 wherein said cover sheet has a transmittance to visible light of at least 75 percent.
Claim 25
Dependent Claim
20 words
The sheeting of claim 1 wherein said cover sheet has a transmittance to visible light of at least 85 percent.
Claim 26
Dependent Claim
45 words
The sheeting of claim 1 wherein said structural layer comprises: polyethylene, or polypropylene; or a copolymer comprising a major portion by weight of at least one of ethylene or propylene and a minor portion by weight of at least one comonomer; or a blend thereof.
Claim 27
Dependent Claim
12 words
The sheeting of claim 25 wherein said inner layer comprises a urethane.
Claim 28
Dependent Claim
19 words
The sheeting of claim 26 wherein said inner layer has a Vicat Softening Point of at least 175° F.
Claim 29
Dependent Claim
16 words
The sheeting of claim 1 wherein said inner layer and said structural layer have been coextruded.
Claim 30
Dependent Claim
207 words
A cellular, encapsulated-lens retroreflective sheeting comprising: (1) a base sheet that comprises a monolayer of retroreflective elements partially embedded in a binder layer; (2) a cover sheet disposed in spaced relation from the layer of retroflective elements; and (3) a network of narrow intersecting bonds that extend between said cover sheet and said base sheet and comprise binder material thermoformed at the point of contact between said bonds and said cover sheet so as to adhere said base sheet and said cover sheet together and form a plurality of cells within which retroreflective elements are hermetically sealed; wherein the cover sheet comprises an inner layer and at least a structural layer, said inner layer having an inside major surface that is in adherent contact with said intersecting bonds, and an outside major surface adhered to said structural layer of said cover sheet, and said inner layer having a lower adhesion to glass than the adhesion to glass of said structural layer, such that said inner layer improved the interaction between said cover sheet and said retroreflective elements so that when said binder material was thermoformed into contact with said cover sheet the flow of said binder material around the front surfaces of said retroreflective elements was improved.
Claim 31
Dependent Claim
207 words
A cellular, encapsulated-lens retroreflective sheeting comprising: (1) a base sheet that comprises a monolayer of retroreflective elements partially embedded in a binder layer; (2) a cover sheet disposed in spaced relation from the layer of retroflective elements; and (3) a network of narrow intersecting bonds that extend between said cover sheet and said base sheet and comprise binder material thermoformed at the point of contact between said bonds and said cover sheet so as to adhere said base sheet and said cover sheet together and form a plurality of cells within which retroreflective elements are hermetically sealed; wherein the cover sheet comprises an inner layer and at least a structural layer, said inner layer having an inside major surface that is in adherent contact with said intersecting bonds, and an outside major surface adhered to said structural layer of said cover sheet, and said inner layer having a lower adhesion to glass than the adhesion to glass of said structural layer, such that said inner layer improved the interaction between said cover sheet and said retroreflective elements so that when said binder material was thermoformed into contact with said cover sheet the flow of said binder material around the front surfaces of said retroreflective elements was improved.
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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) | 1994-11-18 | 1995-05-20 | 1995-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-18 | 1999-05-20 | 1999-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-18 | 2003-05-20 | 2003-11-19 | $7700.00 | Window Closed / Lapsed |