Patent EP0469732A2 successfully refreshed from Google Patents.
EP0469732A2
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EP
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Infrared reflective optical interference film
Assignee: 3M Co
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Filing: 1991-07-10
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Granted: —
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Expires: 2011-07-10
Abstract
Abstract The present invention provides an optical interference film, made of multiple layers of polymers, which reflects wavelengths of light in the infrared region of the spectrum while being substantially transparent to wavelengths of light in the visible spectrum. The optical interference film includes multiple alternating layers of at least first, second, and third diverse, substantially transparent polymeric materials A, B, and C, with the layers being of an optical thickness of between about 0.09 and 0.45 micrometers. Each of the polymeric materials has a different index of refraction, n i , and the refractive index of the second polymeric material is intermediate the respective refractive indices of the first and third polymeric materials.
Inventors
- 👤 Walter J. Schrenk
- 👤 John A. Wheatley
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 23:45
CPC Classifications
B; B32; B32B; B32B27/00; G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/281; G02B5/282; G02B1/00; G02B1/04; G02B5/30; G02B5/3025; G02B5/3033; G02B5/3041; G02B5/305
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
86 words
An optical interference film which reflects light in the infrared region of the spectrum while transmitting light in the visible region of the spectrum comprising multiple layers of at least first, second, and third diverse, substantially transparent polymeric materials A, B, and C, said layers being of an optical thickness of between 0.09 and 0.45 micrometers, wherein the refractive index of said second polymeric material (B) is intermediate the respective refractive index of said first polymeric material (A) and that of said third polymeric material (C).
Claim 2
Dependent Claim
21 words
The optical interference film of Claim 1 in which there is a layer thickness gradient across the thickness of said film.
Claim 3
Dependent Claim
20 words
The optical interference film of Claim 2 in which said layer thicknesses increase monotonically across the thickness of said film.
Claim 4
Dependent Claim
21 words
The optical interference film of any one of the preceding Claims in which the polymeric materials form a repeating unit ABCB.
Claim 5
Dependent Claim
26 words
The optical interference film of any of the preceding Claims, in which the second polymeric material is a copolymer of the first and third polymeric materials.
Claim 6
Dependent Claim
28 words
The optical interference film of any of Claims 1 to 4, in which the second polymeric material is a miscible blend of the first and third polymeric materials.
Claim 7
Dependent Claim
24 words
The optical interference film of Claim 6 in which the first polymeric material is polyvinylidene fluoride, and the third polymeric material is polymethyl methacrylate.
Claim 8
Dependent Claim
28 words
The optical interference film of Claim 6 in which the first polymeric material is a polycarbonate and the third polymeric material is a copolyester based on 1,4-cyclohexanedimethylene terephthalate.
Claim 9
Dependent Claim
40 words
The optical interference film of any one of claims 1 to 4, in which the first polymeric material is polystyrene, the second polymeric material is a copolymer of styrene and methyl methacrylate, and the third polymeric material is polymethyl methacrylate.
Claim 10
Dependent Claim
26 words
The optical interference film of any one Claims 1 to 4, in which one of said polymeric materials is a copolymer of thiodiphenol and bisphenol A.
Claim 11
Dependent Claim
23 words
The optical interference film of any one of Claims 1 to 4, in which one of said polymeric materials is polyethylene 2,6 naphthalate.
Claim 12
Dependent Claim
27 words
The optical interference film of any one of Claims 1 to 4, in which one of said polymeric materials is a copolymer of gluterimide and methyl methacrylate.
Claim 13
Dependent Claim
79 words
The optical interference film of any one of the preceding Claims, wherein the film comprises a plurality of repeating units of the polymeric materials A, B, and C, and wherein, in each repeating unit the optical thickness ratio of material A, f A , is 1/3, the optical thickness ratio of material B, f B , is 1/6, the optical thickness ratio of material C, f C , is 1/3, and n B = (n A n C )
Claim 14
Dependent Claim
33 words
The optical interference film of any one of the preceding Claims, in which said first polymeric material (A) differs in refractive index from said second polymeric material (B) by at least about 0.03.
Claim 15
Dependent Claim
32 words
The optical interference film of any of the preceding Claims, in which said second polymeric material (B) differs in refractive index from said third polymeric material (C) by at least about 0.03.
Claim 16
Dependent Claim
30 words
The use of an optical interference film of any one of the preceding Claims to modify the optical properties of a transparent substrate by laminating the film to the substrate.
References Cited (Backward Citations)
No citation records indexed.
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