WO1993024850A1 - Visibly transparent infrared reflecting film with color masking - Google Patents

Visibly transparent infrared reflecting film with color masking Download PDF

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Publication number
WO1993024850A1
WO1993024850A1 PCT/US1993/003713 US9303713W WO9324850A1 WO 1993024850 A1 WO1993024850 A1 WO 1993024850A1 US 9303713 W US9303713 W US 9303713W WO 9324850 A1 WO9324850 A1 WO 9324850A1
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WO
WIPO (PCT)
Prior art keywords
film
polymeric
layers
color
substantially colorless
Prior art date
Application number
PCT/US1993/003713
Other languages
French (fr)
Inventor
John A. Wheatley
Walter J. Schrenk
Original Assignee
The Dow Chemical Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Dow Chemical Company filed Critical The Dow Chemical Company
Priority to DE69321467T priority Critical patent/DE69321467T2/en
Priority to EP93912326A priority patent/EP0642674B1/en
Priority to KR1019940704263A priority patent/KR950701739A/en
Priority to JP6500527A priority patent/JPH07507401A/en
Publication of WO1993024850A1 publication Critical patent/WO1993024850A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G02B5/281—Interference filters designed for the infrared light
    • G02B5/282—Interference filters designed for the infrared light reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection

Definitions

  • the present invention relates to multilayered infrared reflecting films, and more particularly to polymeric multilayered films which reflect light in the infrared region of the spectrum while transmitting light at substantially all wavelengths in the visible spectrum with an absence of visibly perceived iridescent color.
  • the reflection and transmission spectra for a particular film are primarily dependent on the optical thickness of the individual layers, where optical thickness is defined as the product of the actual thickness of the layer times its refractive index.
  • Films can be designed to reflect infrared, visible, or ultraviolet wavelengths of light depending on the optical thickness of the layers. When designed to reflect infrared wavelengths of light, such prior art films also exhibit higher order reflections in the visible range, resulting in an iridescent appearance for the films.
  • the films produced in accordance with the prior art exhibit iridescence and changing colors as the angle of incident light on the film is changed.
  • infrared reflecting films can be laminated to glass in buildings and automobiles to reduce air conditioning loads.
  • the films may also be laminated to other substantially transparent plastic materials to reflect infrared wavelengths.
  • the films must be substantially transparent to visible light so that the vision of those looking through the glass or plastic is not impaired.
  • the present invention meets that need by providing a polymeric multilayered film made up of multiple alternating layers of diverse 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.
  • a broadband reflective multilayer polymeric film or a suitable broad-band reflective metal oxide or halide coating in combination with the infra red -reflecting film, the film is also capable of masking iridescent color reflected from the infrared-reflecting layers.
  • the polymeric materials need not differ in any respect except in terms of refractive index.
  • adjacent layers may be chemically diverse, if such materials have the . . refractive index, then for purposes of the present invention they are not “diverse".
  • the number of layers may vary within a wide range of from 50 to over 1000 layers.
  • a substantially colorless polymeric multilayered film having at least two major surfaces and which reflects light in the infrared region of the spectrum while transmitting light in the visible region of the spectrum.
  • at least 50 percent, and most preferably at least 70 percent, of the light in the visible region of the spectrum istransmitted through the film.
  • the film also reflects light in the ultraviolet region of the spectrum.
  • Means are also associated with the film for masking any iridescent visible color reflected from the layers so that there is an absence of visibly perceived color reflected from the film.
  • masking it is meant that means are provided to reflect and/or refract light to interfere with the observance of iridescent visible color.
  • the color masking means comprises a masking film which reflects light substantially uniformly 0 over the visible portion of the spectrum.
  • the masking film comprises a sufficient number of alternating layers of substantially transparent diverse first and second polymeric materials having optical thicknesses of not less than 0.45 ⁇ m or not greater than 0.09 ⁇ m.
  • the alternating layers of polymeric materials comprise polycarbonate and polymethyl-methacrylate. 5
  • the color masking film may be located on one or both of the major surfaces of the polymeric film or between interior layers of the film.
  • the color masking film is laminated to the polymeric film. Alternatively, it may be coextruded therewith.
  • the color masking means comprises a substantially colorless metal oxide or metal halide film having sufficient broad band reflectance o in the visible range to mask the iridescent color effects of the infrared reflecting film.
  • the metal oxide or halide film is preferably deposited on the film by conventional coating techniques such as pyrolysis, powder coating, chemical vapor deposition, vacuum coating, or cathode sputtering.
  • the metal oxide or halide film may be located on one or both of the major surfaces of the polymeric film or between interior layers of 5 the film.
  • a preferred metal oxide film is tin oxide.
  • Fig. 1 is a graph illustrating the reflectance of optically thick layers placed behind the infrared reflecting film prepared in accordance with Example 1 ;
  • Fig. 2 is a graph illustrating the color location for each of the reflecting spectra shown in Fig. 1 ;
  • Fig. 3 is a schematic cross-section of a preferred three component polymeric multilayered film of the present invention laminated to the color masking film of the present invention.
  • the present invention provides polymeric multilayered films with a number of desirable properties including infrared reflectivity, substantial transparency to visible light, and the capability to mask iridescent color from the films so that there is an absence of perceived col or ref I ected from the f i I m .
  • the polymeric multilayered film has at least two major surfaces and comprises multiple alternating layers of at least two diverse, substantially transparent polymeric materials, with the layers having an optical thickness of between 0.09 ⁇ m and 0.45 ⁇ m (optically thin layers) and each of the polymeric materials having a different index of refraction such that the layers reflect light in the infrared portion of the spectrum.
  • the transparent polymeric materials differ from each other in refractive index by at least about
  • the polymeric multilayered film includes first, second and third diverse polymeric materials of alternating layers having a repeating pattern ABCB where 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.
  • the preferred three component multilayer film is shown schematically in Fig. 3 as a repeating unit ABCB.
  • the film 10 includes polymer layers 12, 14 and 16, respectively of polymers A, B, and C.
  • the refractive index of the second polymeric material is preferably intermediate the respective refractive indices of the first and third polymeric materials.
  • the optical thickness of a given layer may be defined as the physical thickness, d, times the refractive index, nj, of the polymeric material.
  • the optical thickness ratio of a material, f detox may be defined as: f _njdi
  • 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, fc is 1/3. See Schrenk et al., U.S. Patent No. 5,103,337.
  • there is an intense reflection at the first order wavelength while the reflections at the second, third, and fourth order wavelengths are suppressed.
  • a layer thickness gradient may be introduced across the thickness of the film.
  • the layer thicknesses will increase monotonically across the thickness of the film.
  • “monotonically” it is meant that each layer will consistently increase in thickness with respect to the preceding layer at a predetermined rate.
  • the film includes first and second polymeric materials of alternating layers having a repeating pattern ABAB where the first polymeric material comprises polystyrene and the second polymeric material comprises polymethylmethacrylate.
  • first polymeric material comprises polystyrene
  • second polymeric material comprises polymethylmethacrylate.
  • the present invention provides a color masking film which is associated with the polymeric multilayered film to mask any iridescent visible color reflected from the layers so that there is an absence of visibly perceived color reflected from the film.
  • the color masking means comprises a masking film which reflects light substantially uniformly over the visible portion of the spectrum.
  • the masking film comprises a sufficient number of alternating layers of substantially transparent diverse polymeric materials having broad band reflectance across the visible spectrum which is sufficient to mask perceived iridescent color.
  • the layers in the masking film may comprise optically thick layers, combinations of optically thick and optically very thin layers and optically thin layers and combinations of optically thin and optically thick layers where the layer thicknesses of the optically thin layers in the stack have been varied to produce broad band visible reflectance.
  • the alternating layers of polymeric materials comprise polycarbonate and polymethylmethacrylate.
  • the masking film may be associated with either two- or three-component films, it should be appreciated that the three-component film which suppresses the second through fourth order reflections will not require as many alternating layers of masking film as the two-component film described above, which does not suppress higher order visible reflections.
  • the overall effect of the combination of the polymeric multilayered film with the color masking film is dependent on the relationship between the baseline reflectance and the peak reflectance.
  • the perception factor, Pf is a measure of how the eye perceives changes in the reflectance of the multilayer film.
  • peak reflectance we mean the highest value for reflectance which is measured within the wavelength range of interest.
  • baseline reflectance we mean the average reflectance on either side of the peak wavelength band.
  • the wavelength range of interest is the visible spectrum.
  • the use of the color masking film in association with the polymeric multilayered film causes the baseline reflectance in the visible range to be raised to result in a Pf value of less 0 than 0.5 which substantially masks any iridescent color.
  • the color masking film may be located on one or both of the major sufaces of the infrared reflecting polymeric film or between interior layers of the film. As shown in Fig. 1 , the color masking film 18 is preferably laminated to the polymeric film. Alternatively, the color masking layers may be coextruded with the infrared reflective layers. 5 In another embodiment of the invention, the color masking means comprises a substantially colorless metal oxide or metal halide film having sufficient reflectance to mask the visible iridescent color effects of the infrared reflecting film.
  • the metal oxide or halide film is preferably deposited on the infrared reflecting film by conventional coating techniques such as pyrolysis, powder coating, chemical vapor 0 deposition, vacuum coating, or cathode sputtering.
  • the metal oxide or halide film may be located on one or both of the major surfaces of the film or between interior layers of the film.
  • a preferred metal oxide is tin oxide.
  • Preferred polymeric materials for use in the polymeric multilayered film of the present invention include homopolymers and copolymers of styrene and methylmet acrylate.
  • the first polymeric material may be polystyrene
  • the second polymeric material may be a copolymer of styrene and methyl-methacrylate
  • the third polymeric material may be polymethyl methacrylate.
  • Copolymers of the above and other polymers are also useful in the practice of the present invention and include, for example, copolymers of styrene and methylmethacrylate, styrene and acrylonitrile, and styrene and butadiene.
  • Other copolymers include copolycarbonates of 4,4-thiodi phenol and bisphenol A and copolymers of gluterimide and methyl-methacrylate (KAMAX resins, available from Rohm and Haas).
  • miscible blends of polymers may be used to form any of the polymeric materials by mixing them in the correct proportions for the desired refractive index.
  • suitable miscible blends include polymethylmethacrylate and polyvinylidene fluoride as well as miscible blendsof polycarbonates with: copolymers of polyvinyl chloride and polyvinylidene chloride (SARANTM, available from The Dow Chemical Company), polyesters and copolyesters polycaprolactones, poly(ethylene succinate), poly(ethylene adipate), poly(1 ,4- butylene adipate), poly(1,4-cyclohexanedimethylene succinate), and a copolymer based on 1 ,4- cyclohexanedimethylene terephthalate (PCTG).
  • SARANTM copolymers of polyvinyl chloride and polyvinylidene chloride
  • PCTG copolymers based on 1 ,4- cyclohexanedimethylene ter
  • polymers and their respective refractive indices, are reported in J. Brandrup and E. Immerqut, Polymer Handbook, Third Edition, pp. VI-451-VI461. It is preferred that the polymers have compatible rheologies for coextrusion. That is, as a preferred method of forming the multilayer films is the use of coextrusion techniques, the melt viscosities of the polymers must be reasonably matched to prevent layer instability or nonuniformity. The polymers used also should have sufficient interfacial adhesion so that the films will not delaminate.
  • Multilayer films in accordance with the present invention are most advantageously prepared by employing a multilayered coextrusion device as described in U.S. Patent Nos. 3,773,882 and 3,884,606.
  • a multilayered coextrusion device as described in U.S. Patent Nos. 3,773,882 and 3,884,606.
  • Such a device provides a method for preparing multilayered, simultaneously extruded thermoplastic materials, each of which are of a substantially uniform layer thickness.
  • the feedblock of the coextrusion device receives streams of the diverse thermoplastic polymeric materials from a source such as a heat plastifying extruder.
  • the streams of resinous materials are passed to a mechanical manipulating section within the feedblock. This section serves to rearrange the original streams into a multilayered stream having the number of layers desired in the film.
  • this multilayered stream may be subsequently passed through a series of layer multiplying means in order to further increase the number of layers in the film.
  • the multilayered stream is then passed into an extrusion die which is so constructed and arranged that streamlined flow is maintained therein.
  • Such an extrusion device is described in U.S. Patent No. 3,557,265.
  • the resultant product is extruded to form a multilayered film in which each layer is generally parallel to the major surface of adjacent layers.
  • the configuration of the extrusion die can vary and can be such as to reduce the thickness and dimensions of each of the layers.
  • the precise degree of reduction in thickness of the layers delivered from the mechanical orienting section, the configuration of the die, and the amount of mechanical working of the film after extrusion e all factors which affect the thickness of the individual layers in the final film. It should be appreciated that the polymeric multilayered film and the color masking film may be extruded separately and then laminated together or may be coextruded together.
  • the polymeric multilayered films of the present invention may find a number of uses in areas where infrared reflective properties are desired.
  • the films of the present invention may be used as glazing material.
  • the films of the present invention may also be laminated to glass used in buildings and automobiles to reflect infrared radiation, thus lowering the heating loads.
  • the films may be laminated to other substantially transparent plastics to provide infrared reflective properties.
  • windshields and canopies on certain aircraft are fabricated from tough polymeric resins. Laminating the multilayered film of the present invention to, or incorporating the film into, such polymeric resins would provide protection from infrared radiation while still providing substantial transparency to light in the visible region of the spectrum.
  • the polymeric infrared reflective multilayered films are associated with the color masking film, no iridescence or other undesirable color effects are perceived.
  • the polymeric multilayered film also provides a number of advantages over prior art films in that they are easier to produce because the ability to mask iridescent color in the films allows looser control of layer thickness and simplifies processing. Further, the films of the present invention may be readily retrofitted onto existing structures or incorporated into new structures. In order that the invention may be more readily understood, reference is made to the following example, which is intended to be illustrative of the invention, but is not intended to be limiting in scope. Example
  • a three-component, 657 layer film was made which reflected in the infrared region of the spectrum while maintaining visible transparency.
  • the coextruded film consisted of an ABCB repeat pattern of the foil owing three polymeric components: component A, styrene methyl methacrylate commercially available from the Richardson Polymer Corporation under the designation P-359; component B, a methyl methacrylate styrene copolymer commercially available from the Richardson Polymer Corporation under the designation RPC-440-70; and component C, polymethyl methacrylate commercially available from Rohm and Haas under the designation VS-100.
  • component A styrene methyl methacrylate commercially available from the Richardson Polymer Corporation under the designation P-359
  • component B a methyl methacrylate styrene copolymer commercially available from the Richardson Polymer Corporation under the designation RPC-440-70
  • component C polymethyl methacrylate commercially available from Rohm and Haas under the
  • the optical thickness ratios used for the film were 1/3, 1/6, 1/3, 1/6 as taught in Schrenk et al., U.S. Patent No. 5,103,337. This step achieved suppression of second through fourth order reflections. However, the film sample obtained exhibited non-uniform spots of iridescent color.
  • the reflection spectrum for the film sample is shown as "A" in Fig. 1.
  • a low intensity broad band reflector consisting of 165 alternating optically thick layers of polycarbonate and poly(methyl methacrylate) was placed behind the 657 layer film.
  • the resulting reflection spectrum "B” is shown in Fig. 1. A total of 330 alternating layers of polycarbonate and polymethyl methacrylate was then placed behind the 657 layer sample.
  • FIG. 1 illustrates a plot of color location for each of the three spectra shown in Fig. 1.
  • the graph of Fig. 2 represents CIE 1931 tristimulus color space, where the point labeled D65 represents complete absence of color. See, R. S. Hunter, The Measurement of Appearance (1987). The further a point is away from D65, the more intense the observed color is. For example, a point on the curve plotted in Fig. 2 at 545 nm wavelength will exhibit an intense yellow-green color. Other points at different wavelengths will exhibit intense colors corresponding to the wavelength of light. As shown in Fig. 2, the placement of low intensity broad band reflectors behind the 657 layer film reduced the transparency of the film to about 70 percent and eliminate the objectionable color.

Abstract

A polymeric multilayered film which reflects wavelengths of light in the infrared region of the spectrum while being substantially transparent to wavelengths of light in the visible spectrum without the effects of visibly perceived iridescent color is provided.

Description

VISIBLY TRANSPARENT INFRARED REFLECTING FILM WITH COLOR MASKING
The present invention relates to multilayered infrared reflecting films, and more particularly to polymeric multilayered films which reflect light in the infrared region of the spectrum while transmitting light at substantially all wavelengths in the visible spectrum with an absence of visibly perceived iridescent color.
The reflection and transmission spectra for a particular film are primarily dependent on the optical thickness of the individual layers, where optical thickness is defined as the product of the actual thickness of the layer times its refractive index. Films can be designed to reflect infrared, visible, or ultraviolet wavelengths of light depending on the optical thickness of the layers. When designed to reflect infrared wavelengths of light, such prior art films also exhibit higher order reflections in the visible range, resulting in an iridescent appearance for the films. The films produced in accordance with the prior art exhibit iridescence and changing colors as the angle of incident light on the film is changed.
For some applications, while reflection of infrared wavelengths is desirable, higher order reflections of visible light are not. For example, infrared reflecting films can be laminated to glass in buildings and automobiles to reduce air conditioning loads. The films may also be laminated to other substantially transparent plastic materials to reflect infrared wavelengths. However, the films must be substantially transparent to visible light so that the vision of those looking through the glass or plastic is not impaired.
The need exists in this art for a multilayered film which reflects light in the infrared region of the spectrum, while transmitting light in the visible region of the spectrum which has substantially no visibly perceived iridescent color, and which is easily produced. The present invention meets that need by providing a polymeric multilayered film made up of multiple alternating layers of diverse 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. Through the use of a broadband reflective multilayer polymeric film or a suitable broad-band reflective metal oxide or halide coating in combination with the infra red -reflecting film, the film is also capable of masking iridescent color reflected from the infrared-reflecting layers. By the term "diverse" we mean that the polymeric materials need not differ in any respect except in terms of refractive index. Thus, while adjacent layers may be chemically diverse, if such materials have the . . refractive index, then for purposes of the present invention they are not "diverse". The number of layers may vary within a wide range of from 50 to over 1000 layers.
In accordance with a preferred embodiment of the invention, a substantially colorless polymeric multilayered film is provided having at least two major surfaces and which reflects light in the infrared region of the spectrum while transmitting light in the visible region of the spectrum. Preferably, at least 50 percent, and most preferably at least 70 percent, of the light in the visible region of the spectrum istransmitted through the film. In an alternative embodiment of the invention, the film also reflects light in the ultraviolet region of the spectrum. Means are also associated with the film for masking any iridescent visible color reflected from the layers so that there is an absence of visibly perceived color reflected from the film. By "masking", it is meant that means are provided to reflect and/or refract light to interfere with the observance of iridescent visible color. In one embodiment of the invention, the color masking means comprises a masking film which reflects light substantially uniformly 0 over the visible portion of the spectrum. The masking film comprises a sufficient number of alternating layers of substantially transparent diverse first and second polymeric materials having optical thicknesses of not less than 0.45 μm or not greater than 0.09 μm. In a preferred embodiment of the invention, the alternating layers of polymeric materials comprise polycarbonate and polymethyl-methacrylate. 5 The color masking film may be located on one or both of the major surfaces of the polymeric film or between interior layers of the film. Preferably, the color masking film is laminated to the polymeric film. Alternatively, it may be coextruded therewith.
In another embodiment of the invention, the color masking means comprises a substantially colorless metal oxide or metal halide film having sufficient broad band reflectance o in the visible range to mask the iridescent color effects of the infrared reflecting film. In this embodiment of the invention, the metal oxide or halide film is preferably deposited on the film by conventional coating techniques such as pyrolysis, powder coating, chemical vapor deposition, vacuum coating, or cathode sputtering. The metal oxide or halide film may be located on one or both of the major surfaces of the polymeric film or between interior layers of 5 the film. A preferred metal oxide film is tin oxide.
Accordingly, it is an object of the present invention to provide a substantially colorless polymeric multilayered film which reflects light in the infrared region of the spectrum while transmitting a substantial portion of light in the visible region of the spectrum and which masks iridescent color so that there is essentially no visibly perceived color reflected from the 0 film. These, and other objects and advantages of the present invention, will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
Fig. 1 is a graph illustrating the reflectance of optically thick layers placed behind the infrared reflecting film prepared in accordance with Example 1 ; 5 Fig. 2 is a graph illustrating the color location for each of the reflecting spectra shown in Fig. 1 ; and
Fig. 3 is a schematic cross-section of a preferred three component polymeric multilayered film of the present invention laminated to the color masking film of the present invention.
The present invention provides polymeric multilayered films with a number of desirable properties including infrared reflectivity, substantial transparency to visible light, and the capability to mask iridescent color from the films so that there is an absence of perceived col or ref I ected from the f i I m .
The polymeric multilayered film has at least two major surfaces and comprises multiple alternating layers of at least two diverse, substantially transparent polymeric materials, with the layers having an optical thickness of between 0.09 μm and 0.45 μm (optically thin layers) and each of the polymeric materials having a different index of refraction such that the layers reflect light in the infrared portion of the spectrum. Preferably, the transparent polymeric materials differ from each other in refractive index by at least about
0.03. In addition, at least 50 percent, and preferably at least 70 percent of the light in the visible region of the spectrum istransmitted through the film. While the preferred embodiment of the invention is directed to an infrared reflecting film, the film may also be constructed to reflect light in the ultraviolet region of the spectrum. The capability of reflecting ultraviolet light is useful in many applications. In one of the preferred embodiments of the invention, the polymeric multilayered film includes first, second and third diverse polymeric materials of alternating layers having a repeating pattern ABCB where 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.
The preferred three component multilayer film is shown schematically in Fig. 3 as a repeating unit ABCB. The film 10 includes polymer layers 12, 14 and 16, respectively of polymers A, B, and C.
Additionally, the refractive index of the second polymeric material is preferably intermediate the respective refractive indices of the first and third polymeric materials. The optical thickness of a given layer may be defined as the physical thickness, d, times the refractive index, nj, of the polymeric material. The optical thickness ratio of a material, f„ may be defined as: f _njdi
Σ (nidi) /"-1
where m isthe number of layers in the optical repeat unit, nj is the refractive index of polymers i, and dj isthe layerthickness of polymers i. Thus, for a three component film having a repeating unit ABCB, the optical thickness ratio of material A, fA, is 1/3, the optical thickness ratio of material B, f B, is 1/6, and the optical thickness ratio of material C, fc, 1/3. See Schrenk et al., U.S. Patent No. 5,103,337. For this embodiment of the invention, there is an intense reflection at the first order wavelength, while the reflections at the second, third, and fourth order wavelengths are suppressed.
To produce a film which reflects a broad bandwidth of wavelengths in the solar infrared range (for example, reflection at from 0.7 to 2.0 μm), a layer thickness gradient may be introduced across the thickness of the film. Thus, in one embodiment of the invention, the layer thicknesses will increase monotonically across the thickness of the film. By "monotonically", it is meant that each layer will consistently increase in thickness with respect to the preceding layer at a predetermined rate.
In another embodiment of the invention, the film includes first and second polymeric materials of alternating layers having a repeating pattern ABAB where the first polymeric material comprises polystyrene and the second polymeric material comprises polymethylmethacrylate. As taught by the above-mentioned Radford et al. article, by controlling the optical thickness ratios in a two-component system, different order reflections may be enhanced while others are suppressed. However, it is not possible to suppress multiple successive higher order reflections in a two component multilayer polymer system without resorting to a relatively complex layer synthesis design. Thus, a two component multilayer film designed to reflect strongly the near infrared region of the spectrum will exhibit unwanted reflectivity in the visual region of the spectrum as well because of such higher order reflections. Likewise, even with suppression of higher order reflections, three-component films may still exhibit nonuniform spots of color due to thickness variations in the film and process control problems during extrusion. However, the present invention provides a color masking film which is associated with the polymeric multilayered film to mask any iridescent visible color reflected from the layers so that there is an absence of visibly perceived color reflected from the film.
The color masking means comprises a masking film which reflects light substantially uniformly over the visible portion of the spectrum. The masking film comprises a sufficient number of alternating layers of substantially transparent diverse polymeric materials having broad band reflectance across the visible spectrum which is sufficient to mask perceived iridescent color. The layers in the masking film may comprise optically thick layers, combinations of optically thick and optically very thin layers and optically thin layers and combinations of optically thin and optically thick layers where the layer thicknesses of the optically thin layers in the stack have been varied to produce broad band visible reflectance. In a preferred embodiment of the invention, the alternating layers of polymeric materials comprise polycarbonate and polymethylmethacrylate. While the masking film may be associated with either two- or three-component films, it should be appreciated that the three-component film which suppresses the second through fourth order reflections will not require as many alternating layers of masking film as the two-component film described above, which does not suppress higher order visible reflections.
The overall effect of the combination of the polymeric multilayered film with the color masking film is dependent on the relationship between the baseline reflectance and the peak reflectance. The perception factor, Pf, is a measure of how the eye perceives changes in the reflectance of the multilayer film. The perception factor is defined by the equation Q pf = (A - B)/B, where A represents the peak reflectance from the polymeric film, and B represents the baseline reflectance from the polymeric film. By peak reflectance, we mean the highest value for reflectance which is measured within the wavelength range of interest. By baseline reflectance, we mean the average reflectance on either side of the peak wavelength band. Generally, the wavelength range of interest is the visible spectrum. It has been 5 determined that for a Pf value of 0.5 or less, substantially no iridescent interference color is perceived by an observer. For Pf values of greater than 0.5, iridescent color can be observed. See Wheatley et al., copending U.S. Serial No. 629,520.
The use of the color masking film in association with the polymeric multilayered film causes the baseline reflectance in the visible range to be raised to result in a Pf value of less 0 than 0.5 which substantially masks any iridescent color.
The color masking film may be located on one or both of the major sufaces of the infrared reflecting polymeric film or between interior layers of the film. As shown in Fig. 1 , the color masking film 18 is preferably laminated to the polymeric film. Alternatively, the color masking layers may be coextruded with the infrared reflective layers. 5 In another embodiment of the invention, the color masking means comprises a substantially colorless metal oxide or metal halide film having sufficient reflectance to mask the visible iridescent color effects of the infrared reflecting film. In this embodiment of the invention, the metal oxide or halide film is preferably deposited on the infrared reflecting film by conventional coating techniques such as pyrolysis, powder coating, chemical vapor 0 deposition, vacuum coating, or cathode sputtering. The metal oxide or halide film may be located on one or both of the major surfaces of the film or between interior layers of the film. A preferred metal oxide is tin oxide.
Preferred polymeric materials for use in the polymeric multilayered film of the present invention include homopolymers and copolymers of styrene and methylmet acrylate. 5 For example, the first polymeric material may be polystyrene, the second polymeric material may be a copolymer of styrene and methyl-methacrylate, and the third polymeric material may be polymethyl methacrylate. Copolymers of the above and other polymers are also useful in the practice of the present invention and include, for example, copolymers of styrene and methylmethacrylate, styrene and acrylonitrile, and styrene and butadiene. Other copolymers include copolycarbonates of 4,4-thiodi phenol and bisphenol A and copolymers of gluterimide and methyl-methacrylate (KAMAX resins, available from Rohm and Haas).
Alternatively, miscible blends of polymers may be used to form any of the polymeric materials by mixing them in the correct proportions for the desired refractive index. Examples of suitable miscible blends include polymethylmethacrylate and polyvinylidene fluoride as well as miscible blendsof polycarbonates with: copolymers of polyvinyl chloride and polyvinylidene chloride (SARAN™, available from The Dow Chemical Company), polyesters and copolyesters polycaprolactones, poly(ethylene succinate), poly(ethylene adipate), poly(1 ,4- butylene adipate), poly(1,4-cyclohexanedimethylene succinate), and a copolymer based on 1 ,4- cyclohexanedimethylene terephthalate (PCTG).
Other suitable thermoplastic resins which may find use in the practice of the present invention, along with representative refractive indices, include, but are not limited to: perfluoroalkoxy resins (refractive index = 1.35), polytetrafluoroethylene (1.35), fluorinated ethylene-propylene copolymers (1.34), silicone resins (1.41), polyvinylidene fluoride (1.42), polychlorotrifluoroethylene (1.42), epoxy resins (1.45), poly(butyl acrylate) (1.46), poly(4- methylpentene-1) (1.46), poly(vinyl acetate) (1.47), ethyl cellulose (1.47), polymethyl acrylate (1.48), polypropyl methacrylate (1.48), polyethyi methacrylate (1.48), polyether block amide (1.49), polymethyl methacrylate (1.49), cellulose acetate (1.49), cellulose propionate (1.49), polyvinyl butyral (1.49), polypropylene (1.49), polybutylene (1.50), ionomeric resins such as Surlynτ" (1.51), low density polyethylene (1.51), polyacrylonitrile (1.51), polyisobutylene (1.51), thermoplastic polyesters such as Ecdel™* (1.52), natural rubber (1.52), perbuanan (1.52), polybutadiene (1.52), nylon (1.53), polyacrylic imides (1.53), poly(vinyi chloro acetate) (1.54), polyvinyl chloride (1.54), high density polyethylene (1.54), copolymers of methyl-methacrylate and styrene (1.54), transparent acrylonitrile-butadiene-styrene terpolymer (1.54), allyl diglycol resin (1.55), blends of polyvinylidene chloride and polyvinyl chloride such as SARAN™ resins (1.55), polyalpha-methyl styrene (1.56), styrene-butadiene latexes such as Dow 512-KT" (1.56), polyurethane (1.56), neoprene (1.56), copolymers of styrene and acrylonitrile such as Tyril ™ resin (1.57), copolymers of styrene and butadiene (1.57), polycarbonate (1.59), other thermoplastic polyesters such as polyethylene terephthalate and polyethylene terephthalate glycol (1.60), polystyrene (1.60), polyimide (1.61), polyvinylidene chloride (1.61 ), polydichlorostyrene (1.62), polysulfone (1.63), polyether sulfone (1.65), and polyetherimide (1.66). Other polymers, and their respective refractive indices, are reported in J. Brandrup and E. Immerqut, Polymer Handbook, Third Edition, pp. VI-451-VI461. It is preferred that the polymers have compatible rheologies for coextrusion. That is, as a preferred method of forming the multilayer films is the use of coextrusion techniques, the melt viscosities of the polymers must be reasonably matched to prevent layer instability or nonuniformity. The polymers used also should have sufficient interfacial adhesion so that the films will not delaminate.
Multilayer films in accordance with the present invention are most advantageously prepared by employing a multilayered coextrusion device as described in U.S. Patent Nos. 3,773,882 and 3,884,606. Such a device provides a method for preparing multilayered, simultaneously extruded thermoplastic materials, each of which are of a substantially uniform layer thickness.
The feedblock of the coextrusion device receives streams of the diverse thermoplastic polymeric materials from a source such as a heat plastifying extruder. The streams of resinous materials are passed to a mechanical manipulating section within the feedblock. This section serves to rearrange the original streams into a multilayered stream having the number of layers desired in the film. Optionally, this multilayered stream may be subsequently passed through a series of layer multiplying means in order to further increase the number of layers in the film. The multilayered stream is then passed into an extrusion die which is so constructed and arranged that streamlined flow is maintained therein. Such an extrusion device is described in U.S. Patent No. 3,557,265. The resultant product is extruded to form a multilayered film in which each layer is generally parallel to the major surface of adjacent layers. The configuration of the extrusion die can vary and can be such as to reduce the thickness and dimensions of each of the layers. The precise degree of reduction in thickness of the layers delivered from the mechanical orienting section, the configuration of the die, and the amount of mechanical working of the film after extrusion e all factors which affect the thickness of the individual layers in the final film. It should be appreciated that the polymeric multilayered film and the color masking film may be extruded separately and then laminated together or may be coextruded together.
The polymeric multilayered films of the present invention may find a number of uses in areas where infrared reflective properties are desired. For example, the films of the present invention may be used as glazing material. The films of the present invention may also be laminated to glass used in buildings and automobiles to reflect infrared radiation, thus lowering the heating loads. Further, the films may be laminated to other substantially transparent plastics to provide infrared reflective properties. For example, windshields and canopies on certain aircraft are fabricated from tough polymeric resins. Laminating the multilayered film of the present invention to, or incorporating the film into, such polymeric resins would provide protection from infrared radiation while still providing substantial transparency to light in the visible region of the spectrum.
Because the polymeric infrared reflective multilayered films are associated with the color masking film, no iridescence or other undesirable color effects are perceived. The polymeric multilayered film also provides a number of advantages over prior art films in that they are easier to produce because the ability to mask iridescent color in the films allows looser control of layer thickness and simplifies processing. Further, the films of the present invention may be readily retrofitted onto existing structures or incorporated into new structures. In order that the invention may be more readily understood, reference is made to the following example, which is intended to be illustrative of the invention, but is not intended to be limiting in scope. Example
Employing apparatus as generally described in U.S. Patent Nos. 3,773,882 and 3,759,647, a three-component, 657 layer film was made which reflected in the infrared region of the spectrum while maintaining visible transparency. The coextruded film consisted of an ABCB repeat pattern of the foil owing three polymeric components: component A, styrene methyl methacrylate commercially available from the Richardson Polymer Corporation under the designation P-359; component B, a methyl methacrylate styrene copolymer commercially available from the Richardson Polymer Corporation under the designation RPC-440-70; and component C, polymethyl methacrylate commercially available from Rohm and Haas under the designation VS-100.
The optical thickness ratios used for the film were 1/3, 1/6, 1/3, 1/6 as taught in Schrenk et al., U.S. Patent No. 5,103,337. This step achieved suppression of second through fourth order reflections. However, the film sample obtained exhibited non-uniform spots of iridescent color. The reflection spectrum for the film sample is shown as "A" in Fig. 1. To reduce the amount of color seen in reflection, a low intensity broad band reflector consisting of 165 alternating optically thick layers of polycarbonate and poly(methyl methacrylate) was placed behind the 657 layer film. The resulting reflection spectrum "B" is shown in Fig. 1. A total of 330 alternating layers of polycarbonate and polymethyl methacrylate was then placed behind the 657 layer sample. The resulting reflection spectrum "C" is shown in Fig. 1. Figure 2 illustrates a plot of color location for each of the three spectra shown in Fig. 1. The graph of Fig. 2 represents CIE 1931 tristimulus color space, where the point labeled D65 represents complete absence of color. See, R. S. Hunter, The Measurement of Appearance (1987). The further a point is away from D65, the more intense the observed color is. For example, a point on the curve plotted in Fig. 2 at 545 nm wavelength will exhibit an intense yellow-green color. Other points at different wavelengths will exhibit intense colors corresponding to the wavelength of light. As shown in Fig. 2, the placement of low intensity broad band reflectors behind the 657 layer film reduced the transparency of the film to about 70 percent and eliminate the objectionable color.
While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes in the methods and apparatus disclosed herein may be made without departing from the scope of the invention, which isdefined in the appended claims.

Claims

1. A substantially colorless polymeric multilayered film having at least two major surfaces and which reflects a majority of light in the infrared region of the spectrum while transmitting a majority of light in the visible region of the spectrum comprising, multiple alternating layers of at least two diverse, substantially transparent polymeric materials, said layers having an optical thickness of between 0.09 μm and 0.45 μm and each of said polymeric materials having a different index of refraction such that said layers reflect light in the infrared portion of the spectrum, and means associated with said film for masking any iridescent visible color reflected from said layers such that there is an absence of visibly perceived color reflected from said film.
2. The substantially colorless polymeric multilayered film of claim 1 wherein said film reflects light in the ultraviolet region of the spectrum.
3. The substantially colorless polymeric multilayered film of claim 1 in which said film includes first, second, and third diverse polymeric materials of alternating layers having a repeating pattern ABCB.
4. The substantially colorless polymeric multilayered film of claim 1 in which said film includes first and second polymeric materials of alternating layers having a repeating pattern ABAB.
5. The substantially colorless polymeric multilayered film of claim 1 wherein said color masking means comprise a masking film which reflects light substantially uniformly over the visi bl e porti on of the spectru m .
6. The substantially colorless polymeric multilayered film of claim 1 wherein said color masking means comprise a sufficient number of alternating layers of substantially transparent diverse polymeric materials, a substantial majority of said layers having an optical thickness of not less than 0.45 μm or not greater than 0.09 μm.
7. The substantially colorless polymeric multilayered film of claim 1 wherein said color masking means comprise a substantially colorless metal oxide or metal halide film having sufficient reflectance to mask the visible iridescent color effects of the infrared reflecting film.
8. The substantially colorless polymeric multilayered film of claim 1 wherein said color masking means are located on one or both of said major surfaces of said body or between interior layers of said body.
9. The substantially colorless polymeric multilayered film of claim 16 in which said layer thicknesses increase monotonically across the thickness of said film.
10. The substantially colorless polymeric multilayered film of claim 1 wherein said transparent polymeric materials differ from each other in refractive index by at least about 0.03 and in which at least 70 percent of said light in the visible region of the spectrum is transmitted through said fiim.
PCT/US1993/003713 1992-05-27 1993-04-20 Visibly transparent infrared reflecting film with color masking WO1993024850A1 (en)

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DE69321467T DE69321467T2 (en) 1992-05-27 1993-04-20 INFRARED RADIATION REFLECTIVE FILM WITH MASK AGAINST COLORS FOR VISIBLE LIGHT TRANSPARENT
EP93912326A EP0642674B1 (en) 1992-05-27 1993-04-20 Visibly transparent infrared reflecting film with color masking
KR1019940704263A KR950701739A (en) 1992-05-27 1993-04-20 Visiby transparent infrared reflecting with color masking
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Families Citing this family (80)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5339198A (en) * 1992-10-16 1994-08-16 The Dow Chemical Company All-polymeric cold mirror
KR950704701A (en) * 1992-10-29 1995-11-20 스티븐 에스. 그레이스 Formable reflective multilayer body
JPH0758355A (en) * 1993-05-12 1995-03-03 Optical Coating Lab Inc Uv / ir reflection solar cell cover
US5360659A (en) * 1993-05-24 1994-11-01 The Dow Chemical Company Two component infrared reflecting film
US5946431A (en) * 1993-07-30 1999-08-31 Molecular Dynamics Multi-functional photometer with movable linkage for routing light-transmitting paths using reflective surfaces
US5814367A (en) 1993-08-13 1998-09-29 General Atomics Broadband infrared and signature control materials and methods of producing the same
US6025897A (en) 1993-12-21 2000-02-15 3M Innovative Properties Co. Display with reflective polarizer and randomizing cavity
US5882774A (en) 1993-12-21 1999-03-16 Minnesota Mining And Manufacturing Company Optical film
WO1995017303A1 (en) 1993-12-21 1995-06-29 Minnesota Mining And Manufacturing Company Multilayered optical film
US6804058B1 (en) 1993-12-21 2004-10-12 3M Innovative Properties Company Electroluminescent light source and display incorporating same
US5828488A (en) * 1993-12-21 1998-10-27 Minnesota Mining And Manufacturing Co. Reflective polarizer display
US6096375A (en) * 1993-12-21 2000-08-01 3M Innovative Properties Company Optical polarizer
US6101032A (en) 1994-04-06 2000-08-08 3M Innovative Properties Company Light fixture having a multilayer polymeric film
US5519208A (en) * 1994-09-29 1996-05-21 Esparza; Joel Infrared aided method and apparatus for venous examination
US6235105B1 (en) 1994-12-06 2001-05-22 General Atomics Thin film pigmented optical coating compositions
US5751388A (en) 1995-04-07 1998-05-12 Honeywell Inc. High efficiency polarized display
US6088067A (en) * 1995-06-26 2000-07-11 3M Innovative Properties Company Liquid crystal display projection system using multilayer optical film polarizers
KR100468560B1 (en) 1995-06-26 2005-08-04 미네소타 마이닝 앤드 매뉴팩춰링 캄파니 Multilayer polymer film with additional coatings or layers
US6737154B2 (en) 1995-06-26 2004-05-18 3M Innovative Properties Company Multilayer polymer film with additional coatings or layers
KR100454834B1 (en) 1995-06-26 2005-06-17 미네소타 마이닝 앤드 매뉴팩춰링 캄파니 Light Diffusing Adhesive
US5686979A (en) * 1995-06-26 1997-11-11 Minnesota Mining And Manufacturing Company Optical panel capable of switching between reflective and transmissive states
EP0832392B1 (en) 1995-06-26 2003-08-13 Minnesota Mining And Manufacturing Company Backlight system with multilayer optical film reflector
US6080467A (en) * 1995-06-26 2000-06-27 3M Innovative Properties Company High efficiency optical devices
US5699188A (en) * 1995-06-26 1997-12-16 Minnesota Mining And Manufacturing Co. Metal-coated multilayer mirror
AU706253B2 (en) * 1995-06-26 1999-06-10 Minnesota Mining And Manufacturing Company Transflective displays with reflective polarizing transflector
EP0855043B1 (en) * 1995-06-26 2003-02-05 Minnesota Mining And Manufacturing Company Diffusely reflecting multilayer polarizers and mirrors
AU694884B2 (en) * 1995-06-26 1998-07-30 Minnesota Mining And Manufacturing Company Transparent multilayer device
EP0843953B1 (en) * 1995-08-11 2001-10-17 Minnesota Mining And Manufacturing Company Electroluminescent lamp using multilayer optical film
US5932309A (en) 1995-09-28 1999-08-03 Alliedsignal Inc. Colored articles and compositions and methods for their fabrication
US5825543A (en) * 1996-02-29 1998-10-20 Minnesota Mining And Manufacturing Company Diffusely reflecting polarizing element including a first birefringent phase and a second phase
DE69721505T2 (en) 1996-02-29 2003-11-20 Minnesota Mining & Mfg FILM FOR BRIGHTNESS INCREASE
US5867316A (en) * 1996-02-29 1999-02-02 Minnesota Mining And Manufacturing Company Multilayer film having a continuous and disperse phase
CA2246759A1 (en) * 1996-02-29 1997-09-04 Biswaroop Majumdar An optical film with co-continuous phases
US5661839A (en) 1996-03-22 1997-08-26 The University Of British Columbia Light guide employing multilayer optical film
US5808798A (en) * 1996-03-27 1998-09-15 Minnesota Mining And Manufacturing Co. Nonpolarizing beamsplitter
US5820957A (en) * 1996-05-06 1998-10-13 Minnesota Mining And Manufacturing Company Anti-reflective films and methods
US5976424A (en) * 1996-07-31 1999-11-02 Minnesota Mining And Manufacturing Company Method for making multilayer optical films having thin optical layers
US5808794A (en) 1996-07-31 1998-09-15 Weber; Michael F. Reflective polarizers having extended red band edge for controlled off axis color
US7023602B2 (en) * 1999-05-17 2006-04-04 3M Innovative Properties Company Reflective LCD projection system using wide-angle Cartesian polarizing beam splitter and color separation and recombination prisms
US6486997B1 (en) 1997-10-28 2002-11-26 3M Innovative Properties Company Reflective LCD projection system using wide-angle Cartesian polarizing beam splitter
US5999316A (en) 1997-12-06 1999-12-07 3M Innovative Properties Company Light valve with rotating polarizing element
US6926952B1 (en) 1998-01-13 2005-08-09 3M Innovative Properties Company Anti-reflective polymer constructions and method for producing same
US6788463B2 (en) * 1998-01-13 2004-09-07 3M Innovative Properties Company Post-formable multilayer optical films and methods of forming
US6207260B1 (en) * 1998-01-13 2001-03-27 3M Innovative Properties Company Multicomponent optical body
US6049419A (en) * 1998-01-13 2000-04-11 3M Innovative Properties Co Multilayer infrared reflecting optical body
US6749427B1 (en) * 1998-07-31 2004-06-15 3M Innovative Properties Company Dental articles including post-formable multilayer optical films
US6005713A (en) * 1998-08-21 1999-12-21 3M Innovative Properties Company Multilayer polarizer having a continuous and disperse phase
AU752631B2 (en) * 1998-09-11 2002-09-26 Nike Innovate C.V. Flexible membranes
US6127026A (en) * 1998-09-11 2000-10-03 Nike, Inc. Flexible membranes
US6082025A (en) * 1998-09-11 2000-07-04 Nike, Inc. Flexible membranes
US6630283B1 (en) 2000-09-07 2003-10-07 3M Innovative Properties Company Photothermographic and photographic elements having a transparent support having antihalation properties and properties for reducing woodgrain
WO2002061469A2 (en) * 2001-01-15 2002-08-08 3M Innovative Properties Company Multilayer infrared reflecting film with high and smooth transmission in visible wavelength region and laminate articles made therefrom
US6893489B2 (en) 2001-12-20 2005-05-17 Honeywell International Inc. Physical colored inks and coatings
US20050041292A1 (en) * 2002-05-21 2005-02-24 Wheatley John A. Visible wavelength detector systems and filters therefor
JP2006503733A (en) * 2002-10-24 2006-02-02 スリーエム イノベイティブ プロパティズ カンパニー Fabrication method of high gain optical device having continuous phase and dispersed phase
EP1676698B1 (en) * 2003-10-14 2013-08-14 Toray Industries, Inc. Laminated film
US20050113511A1 (en) * 2003-11-25 2005-05-26 Mead David H. Plastisol coating containing reflective pigments, method of preparing coating on a substrate, and products with such coatings
US20060024491A1 (en) * 2004-07-27 2006-02-02 Engelhard Corporation Optical effect films with customized central layer
US7255920B2 (en) * 2004-07-29 2007-08-14 3M Innovative Properties Company (Meth)acrylate block copolymer pressure sensitive adhesives
US7180779B2 (en) * 2005-07-11 2007-02-20 Atmel Corporation Memory architecture with enhanced over-erase tolerant control gate scheme
US7906202B2 (en) * 2006-09-27 2011-03-15 3M Innovative Properties Company Tear resistant solar control multilayer film
DE602007006837D1 (en) * 2006-10-16 2010-07-08 Valspar Sourcing Inc MULTILAYER THERMOPLASTIC FILM
US7846548B2 (en) * 2006-10-27 2010-12-07 Certainteed Corporation Fence or decking materials with enhanced solar reflectance
US9523516B2 (en) 2008-12-30 2016-12-20 3M Innovative Properties Company Broadband reflectors, concentrated solar power systems, and methods of using the same
US20110299155A1 (en) * 2010-04-13 2011-12-08 Mccarthy Derrick J Energy reflective device
CN103154319B (en) 2010-10-06 2016-08-10 3M创新有限公司 There is coating based on nano silicon and the antireflective article on barrier layer
WO2012047422A1 (en) 2010-10-06 2012-04-12 3M Innovative Properties Company Anti-reflective articles with nanosilica-based coatings
JP5854039B2 (en) * 2011-03-18 2016-02-09 コニカミノルタ株式会社 Heat ray reflective film, method for producing the same, and heat ray reflector
KR102227059B1 (en) 2013-09-06 2021-03-15 쓰리엠 이노베이티브 프로퍼티즈 컴파니 Multilayer reflective polarizer
WO2015106277A1 (en) * 2014-01-13 2015-07-16 The Regents Of The University Of California Wide-range infra-red-reflection and ultra-violet-cut transparent filters based on magnetically responsive photonic crystals
WO2017172564A2 (en) * 2016-04-01 2017-10-05 3M Innovative Properties Company Multilayer fluoropolymer films
US9854968B2 (en) 2016-05-20 2018-01-02 International Business Machines Corporation Behind-eye monitoring using natural reflection of lenses
CN110087883B (en) 2016-12-16 2021-11-09 3M创新有限公司 Infrared reflection type optical transparent component and manufacturing method thereof
US11396161B2 (en) 2017-12-28 2022-07-26 3M Innovative Properties Company Method for preparing multi-layer optical laminates
WO2020203278A1 (en) * 2019-03-29 2020-10-08 積水化学工業株式会社 Laminated glass for vehicles, and vehicle
US11396986B2 (en) 2019-05-23 2022-07-26 Valeo North America, Inc. Apparatus and method for masking residual visible light from an infrared emission source
US11701873B2 (en) * 2020-02-03 2023-07-18 Eenotech, Inc. Thermoregulation articles for exteriors of buildings
WO2023203390A1 (en) 2022-04-19 2023-10-26 3M Innovative Properties Company Broadband reflectors including polymeric layers, and composite cooling systems
WO2023223114A1 (en) 2022-05-19 2023-11-23 3M Innovative Properties Company Light shielding articles and electromagnetic receivers and/or emitters including the same
WO2024061891A1 (en) 2022-09-20 2024-03-28 Behr-Hella Thermocontrol Gmbh Display device with an ir camera for a vehicle

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3711176A (en) * 1971-01-14 1973-01-16 Dow Chemical Co Highly reflective thermoplastic bodies for infrared, visible or ultraviolet light
US4187336A (en) * 1977-04-04 1980-02-05 Gordon Roy G Non-iridescent glass structures
WO1986006658A1 (en) * 1985-05-14 1986-11-20 M&T Chemicals Inc. Method of producing transparent, haze-free tin oxide coatings
EP0404463A2 (en) * 1989-06-20 1990-12-27 The Dow Chemical Company Reflective polymeric body
EP0469732A2 (en) * 1990-07-24 1992-02-05 The Dow Chemical Company Infrared reflective optical interference film
EP0520720A1 (en) * 1991-06-24 1992-12-30 Ford Motor Company Limited Anti-iridescent layer for transparent glazing article
EP0521602A1 (en) * 1991-06-24 1993-01-07 Ford Motor Company Limited Gradient-index anti-iridescent layer for transparent glazing article

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3247392A (en) * 1961-05-17 1966-04-19 Optical Coating Laboratory Inc Optical coating and assembly used as a band pass interference filter reflecting in the ultraviolet and infrared
US3432225A (en) * 1964-05-04 1969-03-11 Optical Coating Laboratory Inc Antireflection coating and assembly having synthesized layer of index of refraction
US3972590A (en) * 1973-09-17 1976-08-03 Optical Coating Laboratory, Inc. Display device which changes color and method
US4971843A (en) * 1983-07-29 1990-11-20 Ppg Industries, Inc. Non-iridescent infrared-reflecting coated glass
US5084356A (en) * 1990-04-20 1992-01-28 E. I. Du Pont De Nemours And Company Film coated with glass barrier layer with metal dopant

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3711176A (en) * 1971-01-14 1973-01-16 Dow Chemical Co Highly reflective thermoplastic bodies for infrared, visible or ultraviolet light
US4187336A (en) * 1977-04-04 1980-02-05 Gordon Roy G Non-iridescent glass structures
WO1986006658A1 (en) * 1985-05-14 1986-11-20 M&T Chemicals Inc. Method of producing transparent, haze-free tin oxide coatings
EP0404463A2 (en) * 1989-06-20 1990-12-27 The Dow Chemical Company Reflective polymeric body
EP0469732A2 (en) * 1990-07-24 1992-02-05 The Dow Chemical Company Infrared reflective optical interference film
EP0520720A1 (en) * 1991-06-24 1992-12-30 Ford Motor Company Limited Anti-iridescent layer for transparent glazing article
EP0521602A1 (en) * 1991-06-24 1993-01-07 Ford Motor Company Limited Gradient-index anti-iridescent layer for transparent glazing article

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