US5064272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Encapsulated-lens retroreflective sheeting and method of making
Assignee: 3M Co
•
Filing: 1990-01-25
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Granted: 1991-11-12
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Expires: 2010-01-25
Abstract
Abstract In encapsulated-lens reflective sheeting of the prior art, a monolayer of glass microspheres is embedded in a binder layer, a specularly reflective layer underlies the microspheres, and a cover film encapsulates the microspheres, within a plurality of hermetically sealed cells. In the invention, a HMW thermoplastic binder film, affords improved structural intregity, greater toughness, and better conformability to irregular surfaces without cracking. The cover film preferably is of the same polymer family as said binder film.
Inventors
- 👤 Terry R. Bailey
- 👤 Roger R. Kult
- 👤 Howard R. Tolliver
- 👤 Arthur D. Dickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:48
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/12; G02B5/126; G02B5/128
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
66 words
Encapsulated-lens retroreflective sheeting comprising a binder layer in which substantially a monolayer of lenses is partially embedded, a specularly reflective layer underlying the lenses, and a cover film sealed to the binder layer along a network of interconnecting lines forming hermetically sealed cells within which the lenses are encapsulated and have an air interface, wherein the improvement comprises: the binder layer is a HMW thermoplastic film.
Claim 2
Dependent Claim
66 words
Encapsulated-lens retroreflective sheeting comprising a binder layer in which substantially a monolayer of lenses is partially embedded, a specularly reflective layer underlying the lenses, and a cover film sealed to the binder layer along a network of interconnecting lines forming hermetically sealed cells within which the lenses are encapsulated and have an air interface, wherein the improvement comprises: the binder layer is a HMW thermoplastic film.
Claim 3
Dependent Claim
23 words
Retroreflective sheeting as defined in claim 1 wherein the weight average molecular weight of the HMW thermoplastic binder film is at least 60,000.
Claim 4
Dependent Claim
19 words
Retroreflective sheeting as defined in claim 1 wherein the melt index of the binder film is less than 300.
Claim 5
Dependent Claim
14 words
Retroreflective sheeting as defined in claim 1 wherein the binder film has been extruded.
Claim 6
Dependent Claim
14 words
Encapsulated-lens retroreflective sheeting as defined in claim 1 wherein the lenses are glass microspheres.
Claim 7
Dependent Claim
20 words
Retroreflective sheeting as defined in claim 1 wherein the elongation of the HMW thermoplastic binder film is at least 100%.
Claim 8
Dependent Claim
18 words
Retroreflective sheeting as defined in claim 1 wherein the HMW thermoplastic binder film comprises an aliphatic urethane polymer.
Claim 9
Dependent Claim
17 words
Retroreflective sheeting as defined in claim 7, the cover film of which comprises an aliphatic urethane polymer.
Claim 10
Dependent Claim
36 words
Retroreflective sheeting as defined in claim 8, the cover film being multi-layer, an outer layer of which is a very thin film comprising an acrylic copolymer of monomers including methyl methacrylate and another acrylate or methacrylate.
Claim 11
Dependent Claim
29 words
Retroreflective sheeting as defined in claim 1 wherein the binder film comprises a copolymer of at least one of ethylene and propylene and a minor proportion of another monomer.
Claim 12
Dependent Claim
24 words
Retroreflective sheeting as defined in claim 10 wherein the binder film comprises an ethylene copolymer and the cover film also comprises an ethylene copolymer.
Claim 13
Dependent Claim
33 words
Retroreflective sheeting as defined in claim 11, the cover film being multi-layer, an outer layer of which is an ionomeric ethylene copolymer, and an inner layer of which is a nonionomeric ethylene copolymer.
Claim 14
Dependent Claim
25 words
Retroreflective sheeting as defined in claim 1 wherein the cover film at its inner surface is of the same polymer family as said binder film.
Claim 15
Dependent Claim
22 words
Retroreflective sheeting as defined in claim 1 in which the microspheres are embedded on the average to over 75% of their diameter.
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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) | 1994-11-11 | 1995-05-13 | 1995-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-11 | 1999-05-13 | 1999-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-11 | 2003-05-13 | 2003-11-12 | $7700.00 | Window Closed / Lapsed |