US5540978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
All-polymeric ultraviolet light reflecting film
Assignee: 3M Innovative Properties Co
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Filing: 1994-05-11
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Granted: 1996-07-30
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Expires: 2014-05-11
Abstract
Abstract An all-polymeric ultraviolet light reflective film which is lower in cost than previously used reflector materials, is weather resistant, and which does not absorb significant amounts of solar ultraviolet energy is provided. The film includes a sufficient number of alternating layers of at least first and second diverse polymeric materials which have an average percent transmission of greater than about 50% between wavelengths of 300-400 nm. A substantial majority of the individual layers of the film have optical thicknesses in the range where the sum of the optical thicknesses in a repeating unit of the polymeric materials is between about 0.15 μm to about 0.228 μm, and the first and second polymeric materials differ from each other in refractive index by at least about 0.03 in the wavelength range of from about 300-400 nm. The reflective film is useful as a reflective material in solar detoxification systems, as a protective material in indoor and outdoor lighting systems, as a UV mirror in the fields of medical imaging, astronomical telescopes, and microscopy or in chemical reactions using UV radiation.
Inventors
- 👤 Walter J. Schrenk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:04
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/30; B32B27/304; B32B27/308; B32B7/00; B32B7/02; B32B7/023; F; F24; F24S; F24S23/00; F24S23/70; F24S23/81; G02B5/00; G02B5/20; G02B5/28; G02B5/285; G02B5/287; G02B5/30; G02B5/3025; G02B5/3033; G02B5/3041; G02B5/305; B32B2307/00; B32B2307/40; B32B2307/416; B32B2551/00; Y; Y02; Y02B; Y02B10/00; Y02B10/20; Y02E; Y02E10/00; Y02E10/40; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/26; Y10T428/261; Y10T428/269; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
183 words
An ultraviolet light reflective all-polymeric film of at least first and second diverse polymeric materials which do not absorb significant amounts of ultraviolet radiation, said at least first and second polymeric materials are selected from the group consisting of polymethyl methacrylate, polyvinylidene fluoride, polychlorotrifluoroethylene, and polymethylpentene-1, the film comprising a sufficient number of alternating layers of at least said first and second polymeric materials which form predetermined repeating units such that at least 30% of ultraviolet light of a wavelength of between about 300-400 nm incident on said film is reflected, said first and second polymeric materials having an average percent transmission of greater then about 50% between wavelengths of 300-400 nm, a substantial majority of the individual layers of said film having optical thicknesses in the range where the sum of the optical thicknesses in one of said repeating units of said polymeric materials is between about 0.15 μm to about 0.228 μm, and wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 in the wavelength range of from about 300-400 nm.
Claim 2
Dependent Claim
183 words
An ultraviolet light reflective all-polymeric film of at least first and second diverse polymeric materials which do not absorb significant amounts of ultraviolet radiation, said at least first and second polymeric materials are selected from the group consisting of polymethyl methacrylate, polyvinylidene fluoride, polychlorotrifluoroethylene, and polymethylpentene-1, the film comprising a sufficient number of alternating layers of at least said first and second polymeric materials which form predetermined repeating units such that at least 30% of ultraviolet light of a wavelength of between about 300-400 nm incident on said film is reflected, said first and second polymeric materials having an average percent transmission of greater then about 50% between wavelengths of 300-400 nm, a substantial majority of the individual layers of said film having optical thicknesses in the range where the sum of the optical thicknesses in one of said repeating units of said polymeric materials is between about 0.15 μm to about 0.228 μm, and wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 in the wavelength range of from about 300-400 nm.
Claim 3
Dependent Claim
26 words
The ultraviolet light reflective polymeric film of claim 1 in which said individual layers have optical thicknesses of between about 0.07 μm to about 0.11 μm.
Claim 4
Dependent Claim
26 words
The ultraviolet light reflective polymeric film of claim 1 in which said first polymeric material is polyvinylidene fluoride and said second polymeric material is polymethyl methacrylate.
Claim 5
Dependent Claim
25 words
The ultraviolet light reflective polymeric film of claim 1 in which said polymeric film is laminated to or coextruded with an infrared light reflecting body.
Claim 6
Dependent Claim
18 words
The ultraviolet light reflective polymeric film of claim 1 in which said film comprises at least 200 layers.
Claim 7
Dependent Claim
31 words
The ultraviolet light reflective polymeric film of claim 1 in which at least 80% of ultraviolet light of a wavelength of between about 300-400 nm incident on said film is reflected.
Claim 8
Dependent Claim
30 words
The ultraviolet light reflective polymeric film of claim 1 in which said polymeric film includes first, second, and third diverse polymeric materials of alternating layers in a repeating unit ABCB.
Claim 9
Dependent Claim
30 words
The ultraviolet light reflective polymeric film of claim 1 in which said polymeric film includes first, second, and third diverse polymeric materials of alternating layers in a repeating unit ABC.
Claim 10
Dependent Claim
23 words
The ultraviolet light reflective polymeric film of claim 1 in which said polymeric film is laminated or coextruded with a transparent substrate material.
Claim 11
Dependent Claim
25 words
The ultraviolet light reflective polymeric film of claim 1 in which said polymeric film is laminated to or coextruded with a visible light reflecting body.
Claim 12
Dependent Claim
25 words
The ultraviolet light reflective polymeric film of claim 1 in which the film includes protective skin layers on both major exterior surfaces of said film.
Claim 13
Dependent Claim
18 words
The ultraviolet light reflective polymeric film of claim 11 in which said protective skin layers comprise polyvinylidene fluoride.
References Cited (Backward Citations)
US3759647A
Cited
US3711176A
Cited
US3773882A
Cited
US3884606A
Cited
US5122905A
Cited
US5122906A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-07-30 | 2000-01-29 | 2000-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-30 | 2004-01-29 | 2004-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-30 | 2008-01-29 | 2008-07-30 | $7700.00 | Window Closed / Lapsed |