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Publication numberUSRE31780 E
Publication typeGrant
Application numberUS 06/521,127
Publication dateDec 25, 1984
Filing dateAug 8, 1983
Priority dateDec 26, 1979
Publication number06521127, 521127, US RE31780 E, US RE31780E, US-E-RE31780, USRE31780 E, USRE31780E
InventorsScott A. Cooper, Ramakrishna Shetty, Jules Pinsky
Original AssigneeThe Mearl Corporation
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Containing terephthalate thermoplastic (co-) polyester
US RE31780 E
Abstract
Improvements in multilayer light-reflecting film are effected by the use of thermoplastic polyester as the high refractive index component of a system in which two or more resinous materials form a plurality of layers.
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Claims(11)
What is claimed is:
1. A transparent thermoplastic resinous laminate film of at least 10 very thin layers of substantially uniform thickness, said layers being generally parallel, the contiguous adjacent layers being of different transparent thermoplastic resinous materials one of which is a .Iadd.terephthalate .Iaddend.thermoplastic polyester or copolyester resin having a refractive index of 1.55-1.61 and the adjacent resinous material having a refractive index which is lower by at least about 0.03, the contiguous adjacent layers differing in refractive index by at least about 0.03.
2. The transparent thermoplastic resinous laminate film of claim 1, wherein said polyester or copolyester is selected from the group consisting of poly(ethylene terephthalate), and a copolyester of cyclohexanedimethanol and an acid comprising terephthalate acid.
3. The transparent thermoplastic resinous laminate film of claim 1 having at least 35 layers.
4. The transparent thermoplastic resinous laminate film of claim 3 having at least about 70 layers.
5. The transparent thermoplastic resinous laminate film of claim 4 wherein said adjacent resinous material has a refractive index which is lower by at least about 0.06.
6. The transparent thermoplastic resinous laminate film of claim 1, wherein said polyester is polybutylene terephthalate.
7. The transparent thermoplastic resinous laminate film of claim 6, wherein said other resinous material is polymethyl methacrylate.
8. The transparent thermoplastic resinous laminate film of claim 1 wherein the outermost layers of said film comprise an impact modified acrylic resin and the thickness of each of the outermost layers is at least 5% of the total thickness of the film.
9. The transparent thermoplastic resinous laminate film of claim 8 wherein said impact modified acrylic resin is a terpolymer of methyl methacrylate, butadiene and acrylonitrile, or methyl methacrylate combined with an elastomer.
10. The transparent thermoplastic resinous laminate film of claim 9 wherein said polyester or copolyester resin is polybutylene terephthlate and adjacent other resin is polymethyl methacrylate.
11. The transparent thermoplastic resinous laminate film of claim 10 of at least 70 substantially uniformly thick layers.
Description
BACKGROUND OF THE INVENTION

The present invention relates to multilayer coextruded light-reflecting films which have a narrow reflection band because of light interference. When the reflection band occurs within the range of visible wavelength, the film is iridescent. Similarly, when the reflection band falls outside the range of visible wavelength, the film is either ultraviolet or infrared reflecting.

The multilayer films and methods by which they can be produced are known in the art. In this connection, the reader's attention is directed to the following U.S. patents which are hereby incorporated by reference: U.S. Pat. Nos. 3,328,003; 3,442,755; 3,448,183; 3,479,425; 3,480,502; 3,487,505; 3,511,903; 3,549,405; 3,555,128; 3,565,985; 3,576,707; 3,642,612; 3,711,176; 3,759,647; 3,773,882; and 3,801,429.

The multilayer films are composed of a plurality of generally parallel layers of transparent thermoplastic resinous material in which the contiguous adjacent layers are of diverse resinous material whose index of refraction differs by at least about 0.03. The film contains at least 10 layers and more usually at least 35 layers and, preferably, at least about 70 layers.

The individual layers of the film are very thin, usually in the range of about 30 to 500 nm, preferably about 50-400 nm, which causes constructive interference in light waves reflected from the many interfaces. Depending on the layer thickness and the refractive index of the polymers, one dominant wavelength band is reflected and the remaining light is transmitted through the film. The reflected wavelength is proportional to the sum of the optical thicknesses of a pair of layers. The reflected wavelength can be calculated by the formula ##EQU1## In this formula, λ is the reflected wavelength, M is the order of reflection, t is the layer thickness, n is the refractive index, and 1 and 2 indicate the polymer of the first layer and the polymer of the second layer, respectively. The quantity nt is the optical thickness of a layer. For first order reflection, i.e. when M is 1, visible light is reflected when the sum of optical thicknesses falls between about 200 and 350 nm. When the sum is lower than about 200, the reflection is in the ultraviolet region of spectrum and when the sum is greater than about 350 nm, the reflection is in the infrared region.

The quantity of the reflected light (reflectance) and the color intensity depend on the difference between the two refractive indexes, on the ratio of optical thicknesses of the layers, on the number of layers and on the uniformity of the thicknesses. If the refractive indexes are the same, there is no reflection at all from the interfaces between the layers. In the multilayer films, the refractive indexes of contiguous adjacent layers differ by at least 0.03 and preferably by at least 0.06 or more. For first order reflections, reflectance is highest when the optical thicknesses of the layers are equal although suitably high reflectances can be achieved when the ratio of the two optical thicknesses falls between 5:95 and 95:5. Distinctly colored reflections are obtained with as few as 10 layers; however, for maximum color intensity it is desired to have between 35 and 1000 or even more layers. High color intensity is associated with a reflection band which is reltively narrow and which has high reflectance at its peak. It should be recognized that although the term "color intensity" has been used here for convenience, the same considerations apply to the invisible reflection in the ultraviolet and infrared ranges.

The multilayer films can be made by a chill roll casting technique using a conventional single manifold flat film die in combination with a feedblock which collects the melts from each of two or more extruders and arranges them into the desired layer pattern. Feedblocks are described in the aforementioned U.S. Pat. Nos. 3,565,985 and 3,773,882. The feedblocks can be used to form alternating layers of either two components (i.e. ABAB . . . ); three components (e.g. ABCABCA . . . or ACBCACBC . . . ); or more. The very narrow multilayer stream flows through a single manifold flat film die where the layers are simultaneously spread to the width of the die and thinned to the final die exit thickness. The number of layers and their thickness distribution can be changed in inserting a different feedport module. Usually, the outermost layer or layers on each side of the sheet are thicker than the other layers. This thicker skin may consist of one of the components which makes up the optical core; may be a different polymer which is utilized to impart desirable mechanical, heat sealing, or other properties; or may be a combination of these.

The high refractive index component used heretofore in commercial production has been polystyrene (refractive index 1.60). Other high index resins which are optically suitable but which have disadvantages in terms of cost or difficulty of extrusion in the multilayer process are polycarbonate (1.59), vinylidene chloride (85%)-vinyl chloride (15%) copolymer (1.61), and polydichlorostyrene (1.62). Polystyrene in combination with such lower refractive index polymers as poly(methyl methacrylate), polypropylene, and ethylene vinyl acetate, all of which are close to 1.50 in refractive index, produces iridescent films of desirable optical properties which, however, reveal deficiencies in certain mechanical properties. For example, the adhesion between individual layers of the multilayer structure may be insufficient, and the film may suffer from internal delamination or separation of layers during use. The iridescent film is often adhered to paper or board for its decorative effect, and is then used for greeting cards, cartons, and the like. Delamination of the film is unsightly and may even lead to separation of the glued joints of carton. In addition, the solvent resistance and heat stability of such films are not as great as desired for widespread utilization.

Accordingly, it is the object of this invention to provide new and improved multilayer light-reflecting films which exhibit increased resistance to delamination, improved solvent resistance and/or improved heat stability. This and other objects of the invention will become apparent to those skilled in this art from the following detailed description.

SUMMARY OF THE INVENTION

This invention relates to an improved multilayer light-reflecting film and more particularly to a transparent thermoplastic resinous film of at least 10 generally parallel layers in which the contiguous adjacent layers are of diverse transparent thermoplastic resinous material differing in refractive index by at least about 0.03 and at least one of the resinous materials being a thermoplastic polyester or copolyester resin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

It has now been found that the objectives of this invention are realized by employing as the high refractive index component a transparent thermoplastic polyester or copolyester resin which is characterized by a refractive index of about 1.55 to about 1.61. Examples of usable thermoplastic polyester resins include poly(ethylene terephthalate) (PET) which is made by reacting either terephthalic acid or dimethyl terephthalate with ethylene glycol; polybutylene terephthalate (PBT) which is made by the catalyzed condensation of 1,4-butanediol with either terephthalic acid or dimethyl terephthalate; and the various thermoplastic copolyesters which are synthesized using more than one glycol and/or more than one dibasic acid. PETG copolyester, for example, is a glycol modified PET made from ethylene glycol and cyclohexanedimethanol (CHDM) and terephthalic acid; PCTA copolyester is an acid modified copolyester of CHDM with terephthalic and isophthalic acids. Iridescent films of high color intensity and greatly improved properties are obtained by using the thermoplastic polyester resins as the high refractive index resins in conjunction with thermoplastic resins of a lower refractive index. A list of typical resins falling in the latter category is given in Table 1 and it will be appreciated that in making suitable combinations, a refractive index difference of at least about 0.03, preferably at least about 0.06, is maintained.

              TABLE 1______________________________________                  ApproximatePolymer name:          Refractive Index______________________________________FEP (fluorinated ethylene-propylene                  1.34copolymerPolytetrafluoroethylene                  1.35Polyvinylidenefluoride 1.42Polychlorotrifluoroethylene                  1.42Polybutyl acrylate     1.46Polyvinyl acetate      1.47Ethyl cellulose        1.47Polyformaldehyde       1.48Polyisobutyl methacrylate                  1.48Polybutyl methacrylate 1.48Polymethyl acrylate    1.48Polypropyl methacrylate                  1.48Polyethyl methacrylate 1.48Polymethyl methacrylate                  1.49Cellulose acetate      1.49Cellulose propionate   1.49Cellulose acetate-butyrate                  1.49Cellulose nitrate      1.49Polyvinyl butyral      1.49Polypropylene          1.49Ethylene vinyl acetate 1.50Low density polyethylene (branched)                  1.51Polyisobutylene        1.51Ionomer                1.51Natural rubber         1.52Perbunan               1.52Polybutadiene          1.52Nylon (condensation copolymer of hexa-                  1.53methylene-diamine and adipic acidPolyvinyl chloroacetate                  1.54Polyethylene (high density linear)                  1.54Polyvinylchloride      1.54A copolymer of 85 parts by weight methyl                  1.54methacrylate and 33 parts by weightstyrene______________________________________

A preferred combination in accordance with this invention involves the use of polybutylene terephthalate (PBT) as the thermoplastic polyester and poly(methyl methacrylate) (PMMA) as the low refractive index material. To prepare the film, the polyester was fed to the feedblock from one extruder and the PMMA was fed from a second extruder to form a 0.8 mil (20 μm) thick film consisting of 115 optical layers and two polyester skin layers. Each skin layer was about 10% of the thickness of the total film. The polyester optical layers were each about 0.2 μm in optical thickness, the PMMA optical layers each about 0.1 μm. A 112-centimeter die was used to produce a 90-centimeter wide film of uniform overall thickness. The film was brightly iridescent, and was prevailing green and red when seen by reflection at perpendicular incidence.

To evaluate this polyester/PMMA film for resistance to delamination, one surface of the film was restrained either by backing with adhesive coated tape or by adhesive lamination to rigid paperboard. Pressure sensitive tape was applied to the other surface of the film. The film withstood many pulls on the tape without any sign of delamination, even when the tape was applied at the edge of the film. The test was made still more severe by wiping the exposed side with a solvent, such as toluene, which promotes delamination in other types of iridescent film, e.g. polystyrene (PS)/propylene-ethylene copolymer (PP) and PS/ethylene vinyl acetate (EVA). The polyester/PMMA film withstood the tape test without any sign of delamination.

Other prior art films similarly failed in these delamination tests. For example, the brightly iridescent film consisting of PS/PMMA was so brittle that it fractured under the conditions of the test. Iridescent films consisting of PS/PP and PS/EVA delaminated readily under the same test conditions.

A number of other properties are also superior to those of previously known films. These include excellent mar resistance, temperature resistance, and solvent resistance. The latter is most important for film which is brought in contact with adhesives, printing inks, or lacquers containing organic solvents.

To test the solvent resistance of the film, each of a number of solvents was applied to the surface of individual samples by means of a soaked cotton swab. The solvent was permitted to air dry. The PBT/PMMA iridescent film underwent no change on treatment with aliphatic or aromatic hydrocarbons or their mixtures, alcohols, aliphatic esters such as ethyl acetate and butyl acetate, or ketones such as acetone and methyl isobutyl ketone. The previously known commercial films of PS/PMMA, PS/PP, and PS/EVA, evaluated by the same technique, suffered crazing, loss of gloss, change of color, or loss of color when exposed to several of these solvents, including heptane, toluene, and various commercial mixed hydrocarbon solvents, as well as butyl acetate and methyl isobutyl ketone.

Temperature stability of the polyester film was similarly superior to that of previously known films. Samples were placed in air-circulating ovens for 30 minutes at various temperatures. The temperature of first change was noted, with the following results: Polyester film PBT/PMMA, 220 C.; prior art films PS/PMMA, 150 C.; PS/PP, 130 C.; PS/EVA, 120 C. Improved temperature stability is very important for applications in which the films is to be laminated or adhered to another surface by a technique which requires elevated temperature.

It was mentioned previously that the skin layer is thicker than the optical layers. Each skin layer should have a thickness of at least about 5% of the total thickness of the film, and may be as great as about 40% of the total film thickness. A variant of the film utilizes a third extruder to provide on each surface an outer skin of thermoplastic impact-modified acrylic resin. This skin layer may supplant the usual skin layer which consists of one of the optical components, or may be added on top of it. Each impact acrylic layer should be in thickness at least about 5% of the total thickness of the film; the sum of each impact acrylic layer and the adjacent optical resin skin layer, if any, may be as great as about 40% of the total film thickness or even greater.

Impact acrylic imparts improved winding characteristics and resistance to blocking, and provides a surface which is very receptive to adhesives, printing inks, and hot stamping foils. Such film in addition has improved resistance to ultraviolet light.

The impact-modified acrylic resin may be a copolymer, e.g. methyl methacrylate polymerized with another monomer such as methyl acrylate, ethyl acrylate, butyl acrylate, acrylonitrile, styrene, or butadiene; a terpolymer or multi-polymer made from three or more of such monomers; or a blend of methyl methacrylate with elastomer, vinyl, or other modifiers. Commercial impact acrylics are available as Lucite T-1000 (DuPont) and Plexiglas DR (Rohm & Haas).

The two-component iridescent films display excellent resistance to delamination, and good iridescent color regardless of which component serves as the skin. Other properties may be enhanced when one or the other component is the skin layer. With polyester/PMMA, for example, the film is more flexible with polyester as the skin layer, and more brittle with PMMA as the skin layer. Thus, polyester is preferred for the skin where flexibility is desirable, as in decorative wrappings; PMMA is preferred where the film is to be cut into small pieces such as flakes or "glitters". The choice depends on the particular pair of components in the optical core and the applications for which the film is intended.

The use of a third resin as the skin layer substantially decreases the importance of the internal sequence, since the properties are modified by the specific skin resin. Impact acrylic as a skin may be adjacent to either polyester or PMMA in the above example. In other combinations, it may be desirable to choose a particular sequence in order to assure maximum adhesion between the skin layer and the multilayer optical core.

In order to further illustrate the present invention, various examples are set forth below and it will be appreciated that these examples are not intended to limit the invention. Unless otherwise stated, all temperatures are in degrees Centigrade and all parts and percentages are by weight throughout the specification and claims.

EXAMPLE 1 Alternating Layers of Polyester and Poly(methyl methacrylate) (PMMA)

Polybutylene terephthalate thermoplastic polyester was fed to the feedblock from one extruder and PMMA from a second extruder to form a 0.75 mil (19 μm) thick film consisting of 115 optical layers and 2 polyester skin layers. Each skin layer was about 20% of the thickness of the total film. The polyester optical layers were each about 0.15 μm in optical thickness, the PMMA layers about 0.07 μm. The film was brightly iridescent, and was prevailingly blue and green when seen by reflection at perpendicular incidence. The film displayed excellent resistance to delamination as well as superior solvent resistance and temperature stability.

EXAMPLE 2 Polyester/PMMA multilayer structure with additional skin layers containing impact modified acrylic copolymer

A multilayer structure similar to that of Example 1 was prepared, except that a second skin layer was added to each surface by means of a third extruder. This outer skin layer consisted of a mixture of equal parts of two resins, (1) PMMA and (2) an impact-modified acrylic resin, namely, Lucite T-1000 (DuPont) a polymethyl methacrylate modified with elastomer. This film was superior to that of Example 1 in that its winding and antiblocking properties were superior, and it was more suitable for printing and hot stamping.

EXAMPLES 3-15

Various thermoplastic polyester polymers and copolymers were utilized in conjunction with a number of polymers of lower refractive index, sometimes in two-component structures, sometimes in structures utilizing additional components for skin layers, as shown in the following tabulation. All examples yielded intensely iridescent films with improved heat stability and, .[.expecially.]. .Iadd.especially .Iaddend.where PMMA was the low index polymer, improved resistance to delamination.

______________________________________  High Index            Low Index Skin LayerExample  Polymer   Polymer   Polymer(s)______________________________________3      PBT       EVA       PBT4      PBT       EVA       PMMA and impact modified                      polymethyl methacrylate5      PBT       PP        PBT6      PBT       PP        PP7      PBT       PP        PMMA and impact modified                      polymethyl methacrylate8      PBT       Ionomer   PBT9      PBT       Ionomer   Impact modified copolymer                      of methyl methacrylate and                      butyl acrylate10     PETG      PMMA      PETG11     PETG      PMMA      PMMA and impact modified                      polymethyl methacrylate12     PET       PMMA      PET13     PET       PMMA      Modified acrylic terpolymer                      of methyl methacrylate,                      butadiene, and acrylonitrile14     PCTA      PMMA      PCTA15     PCTA      PMMA      PMMA and impact modified                      polymethyl methacrylate______________________________________

Various changes and modifications can be made in the present invention without departing from the spirit and scope thereof. For example, while the invention has been described with reference to cast film, flat film type of film production, iridescent films can also be made by the tubular process (blown film). Accordingly, the various embodiments disclosed herein were for the purpose of illustration only and where not intended to limit the invention.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3479425 *Jul 22, 1965Nov 18, 1969Dow Chemical CoExtrusion method
US3511903 *May 5, 1967May 12, 1970Dow Chemical CoMethod for extruding thermally degradable polymers
US3565985 *Apr 10, 1969Feb 23, 1971Dow Chemical CoMethod of preparing multilayer plastic articles
US3759647 *Mar 15, 1972Sep 18, 1973Turner Alfrey UsApparatus for the preparation of multilayer plastic articles
US3773882 *Oct 1, 1971Nov 20, 1973Dow Chemical CoMethod for multilayer coextrusion
US3801429 *Oct 4, 1971Apr 2, 1974Dow Chemical CoMultilayer plastic articles
US4218510 *Jan 2, 1979Aug 19, 1980Minnesota Mining And Manufacturing CompanySelf unified, heat sealable, multilayer film
GB1141981A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5077129 *Feb 22, 1991Dec 31, 1991Wolff Walsrode AgStretched polypropylene films having good surface slip
US5103337 *Jul 24, 1990Apr 7, 1992The Dow Chemical CompanyInfrared reflective optical interference film
US5353154 *Nov 2, 1992Oct 4, 1994The Dow Chemical CompanyPolymeric reflective materials utilizing a back light source
US5448404 *May 13, 1994Sep 5, 1995The Dow Chemical CompanyPolymer body with optical layers
US5568316 *Apr 13, 1995Oct 22, 1996The Dow Chemical CompanyFormable reflective multilayer body
US5576089 *Jan 7, 1994Nov 19, 1996Southpac Trust International, Inc.Optical effect material and methods
US5634318 *May 30, 1995Jun 3, 1997Southpac Trust International, Inc.Wrapping method
US5701720 *May 30, 1995Dec 30, 1997Southpac Trust International, Inc.Optical effect material and methods
US5727362 *Sep 20, 1996Mar 17, 1998Southpac Trust International, Inc.For forming a decorative cover about a flower pot
US5775057 *Sep 20, 1996Jul 7, 1998Southpac Trust International, Inc.Optical effect material and methods
US5861199 *Sep 20, 1996Jan 19, 1999Southpac Trust International, Inc.Optical effect material and methods
US5891286 *Feb 7, 1997Apr 6, 1999Southpac Trust International Inc.Method of forming curled or crimped decorative elements having an optical effect
US5921061 *Sep 20, 1996Jul 13, 1999Southpac Trust International, Inc.Optical effect material and methods
US5985380 *Jun 15, 1998Nov 16, 1999Southpac Trust International, Inc.Decorative grass made from optical effect material
US6269590May 11, 2000Aug 7, 2001Southpac Trust International, Inc.Floral wrapper having printed design with shaded and highlighted areas
US6291056Jul 1, 1998Sep 18, 2001Engelhard CorporationFlakes from multilayer iridescent films for use in paints and coatings
US6295761May 8, 2000Oct 2, 2001Southpac Trust International, Inc.Floral wrapper having printing design with shaded and highlighted areas
US6381924Jun 30, 2000May 7, 2002Southpac Trust International, Inc.Floral wrapper having printed design with shaded and highlighted areas
US6442894Aug 6, 2001Sep 3, 2002Southpac Trust International, Inc.Floral wrapper having printed design with shaded and highlighted areas
US6455140Jan 13, 1999Sep 24, 20023M Innovative Properties CompanyVisible mirror film glitter
US6475609Jan 13, 1999Nov 5, 20023M Innovative Properties CompanyGlitter
US6498683 *Nov 22, 1999Dec 24, 20023M Innovative Properties CompanyMultilayer optical bodies
US6574918Jun 25, 2001Jun 10, 2003Southpac Trust International, Inc.Floral wrapper having printed design with shaded and highlighted areas
US6588309Jan 18, 2002Jul 8, 2003Donald E. WederDecorative grass having a three-dimensional pattern and methods for producing same
US6596352Jan 25, 2002Jul 22, 2003Southpac Trust International, Inc.Decorative grass having a three-dimensional pattern and methods for producing same
US6613421Sep 25, 2001Sep 2, 20033M Innovative Properties CompanyOptical film
US6635337Aug 10, 2001Oct 21, 20033M Innovative Properties CompanyOptical film
US6708447Jan 8, 2003Mar 23, 2004Southpac Trust International, Inc.Floral wrapper having printed design with shaded and highlighted areas
US6744561Aug 9, 2002Jun 1, 20043M Innovative Properties CompanyMultilayer optical bodies
US6749427 *Jul 31, 1998Jun 15, 20043M Innovative Properties CompanyDental articles including post-formable multilayer optical films
US6788463Apr 3, 2002Sep 7, 20043M Innovative Properties CompanyPost-formable multilayer optical films and methods of forming
US6888677Oct 17, 2003May 3, 20053M Innovative Properties CompanyMultilayer optical bodies
US6986223Apr 16, 2004Jan 17, 2006Wanda M. Weder and William F. Straeter, not individually but solely as Trustees of The Family Trust U/T/A dated December 8, 1995Floral wrapper having printed design with shaded and highlighted areas
US7000349May 9, 2003Feb 21, 2006William M.Weder And William F. StraeterFloral wrapper having printed design with shaded and highlighted areas
US7017300Feb 8, 2005Mar 28, 2006Wanda M. Weder And William F. StraeterMethod for providing a decorative cover for a floral grouping
US7077649Jun 15, 2004Jul 18, 20063M Innovative Properties CompanyDental articles including post-formable multilayer optical films
US7083847Sep 2, 2003Aug 1, 20063M Innovative Properties CompanyOptical film
US7141297Mar 24, 2005Nov 28, 20063M Innovative Properties CompanyMultilayer optical bodies
US7297393Jul 31, 2006Nov 20, 20073M Innovative Properties CompanyOptical film
US7524770 *Nov 28, 2005Apr 28, 2009Samsung Electronics Co., Ltd.Methods of forming image sensor microlens structures
US7608330Feb 27, 2006Oct 27, 2009Jds Uniphase CorporationHigh chroma optically variable color-shifting glitter comprising particles having interference structure coating
US7729026Dec 12, 2006Jun 1, 2010Jds Uniphase CorporationSecurity device with metameric features using diffractive pigment flakes
US7767123Oct 11, 2005Aug 3, 2010Jds Uniphase CorporationProducing two distinct flake products using a single substrate
US7842980Mar 12, 2009Nov 30, 2010Samsung Electronics Co., Ltd.Image sensor microlens structures and methods of forming the same
US7867621Sep 19, 2005Jan 11, 2011The Boeing CompanyWide area lightning diverter overlay
US7973998May 19, 2008Jul 5, 2011Serious Materials, Inc.Temperature activated optical films
US8182924May 14, 2010May 22, 20123M Innovative Properties CompanyOptical body having polyacrylate skin layer
US8409720May 14, 2010Apr 2, 20133M Innovative Properties CompanyOptical body having polyacrylate skin layer
US8715824Sep 15, 2004May 6, 2014The Boeing CompanyApplique
USRE34605 *Dec 11, 1992May 10, 1994The Dow Chemical CompanyInfrared reflective optical interference film
EP0298603A2 *Jun 7, 1988Jan 11, 1989The Mearl CorporationSimulated mother-of-pearl
EP1710604A1Mar 1, 2006Oct 11, 2006JDS Uniphase CorporationHigh chroma optically variable color-shifting glitter
EP2067825A2Dec 4, 2008Jun 10, 2009JDS Uniphase CorporationReinforced glitter
WO1993016878A1 *Nov 25, 1992Sep 2, 1993Dow Chemical CoAll-polymeric ultraviolet reflecting film
WO2000001526A1 *Apr 29, 1999Jan 13, 2000Engelhard CorpFlakes from multilayer iridescent films for use in paints and coatings
WO2008137620A1 *May 2, 2008Nov 13, 2008Basf CorpNon-specular iridescent films
Classifications
U.S. Classification428/212, 264/173.16, 264/173.12, 428/480, 428/213, 359/588, 264/1.31, 428/483
International ClassificationB32B7/02, G02B5/28
Cooperative ClassificationB32B7/02, G02B5/287
European ClassificationG02B5/28F2, B32B7/02