Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/20—Filters
  • G02B5/28—Interference filters
  • G02B5/285—Interference filters comprising deposited thin solid films
  • G02B5/287—Interference filters comprising deposited thin solid films comprising at least one layer of organic material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44F—SPECIAL DESIGNS OR PICTURES
  • B44F1/00—Designs or pictures characterised by special or unusual light effects
  • B44F1/08—Designs or pictures characterised by special or unusual light effects characterised by colour effects
  • B44F1/14—Iridescent effects

Definitions

• the present invention is directed to iridescent films with multiple reflection peaks having unique color and effects.
• this invention is directed to multilayer coextruded light- reflecting films which have a narrow reflection band due to light interference.
• the film 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.
• Such multilayer films and methods by which they can be produced are known in the art. They are described, for instance, in U.S. Patents 3,565,985; 3,759,657; 3,773,882; and 3,801 ,429 and other patents.
• 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.
• 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 thickness of a pair of layers.
• the quantity of the reflected light (reflectance) and the color intensity depend on the difference between the two refractive indices, on the ratio of optical thicknesses of the layers, on the number of layers and on the uniformity of the thickness. If the refractive indices are the same, there is no reflection at all from the interfaces between the layers.
• the refractive indices 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. Distinct color reflections are obtained with as few as 10 layers.
• color intensity it is desired to have between 35 and 1 ,000 or even more layers.
• High color intensity is associated with a reflection band which is relatively 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.
• the number of layers and their thickness distribution can be changed by inserting a different feedblock module.
• 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.
• U.S. Patents Nos. Re. 31 ,780; 4,937,134; and 5,089,318 Some recent developments in the iridescent film are described in U.S. Patents Nos. Re. 31 ,780; 4,937,134; and 5,089,318.
• U.S. Patent Re. 31 ,780 describes using a thermoplastic terephthalate polyester or copolyester resin as the high refractive index component of the system. Formation of elastomeric interference films is described in U.S. Patent No. 4,937,134 in which all of the resinous materials are certain thermoplastic polyurethanes, polyester block amides or flexible copolyesters.
• 5,089,318 discloses improved multilayer light-reflecting 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 an engineering thermoplastic elastomer resin.
• Conventional multi-nanolayered films designed for optical and decorative purposes possess uninterrupted layering of the color-generating polymer pairs. This design maximizes the transparency of the structure to facilitate constructive interference of incident light throughout the optical core.
• Prior art laminated films has also exaggerated poor color uniformity across the web and as a result poorly conceived colors have been produced.
• Other prior art used higher order films to create multiple refection peaks that are generally weaker than the first order peaks and are very difficult to control.
• the present invention is directed to laminated films that generate unique color via two distinct reflection peaks.
• These multiple peak iridescent films travel through the L*a*b* color space in unique ways, generating new and interesting colors.
• combination colors such as magenta, gold, turquoise, etc. can now be generated with a single standard feed ring.
• the iridescent film is, as there described, a transparent thermoplastic resinous coextruded laminated film of at least 10 very thin layers, preferably at least about 35 layers and more preferably at least about 70 layers, each of which is usually in the range of about 30-500 nm and more preferably about 50-400 nm, with the layers being generally parallel and the contiguous adjacent layers being of different transparent thermoplastic resinous materials differing in refractive index by at least about 0.03, and more preferably, at least about 0.06.
• the outermost layers of the film constituting a skin are each at least about 5% of the total thickness of the film.
• thermoplastic resinous material used to prepare iridescent film heretofore can be used in the present invention as long as the individual materials have the characteristics set forth above and likewise, the combination of selected resinous materials has the characteristics detailed above.
• Useful polymers for the film layers include polyesters, polyacrylates, polyethylene vinyl acetate, polyolefins, and polystryenes.
• polyesters include polyethylene terephthalate, polybutylene terephthalate, glycol modified polyethylene terephthalate made from ethylene glycol, and cyclohexamedimethanol characterized by a refractive index of about 1.55 to 1.61 , and polyethylene naphthalate as disclosed in commonly assigned US Patent 6,475,608, incorporated herein by reference.
• a useful polyacrylate includes polymethyl methacrylate.
• useful films include alternating layers of polybutylene terephthalate (hereinafter "PBT") and polymethyl methacrylate (hereinafter “PMMA”); alternating layers of polyethylene terephthalate (PET) and polymethyl methacrylate; alternating layers of polystyrene and ethylene vinyl acetate (hereinafter “EVA”); alternating layers of polyethylene naphthalate and polymethyl methacrylate; alternating layers of polyethylene terephthalate and ethylene methyl acrylate (hereinafter "EMA”); and alternating layers of polyethylene naphthalate and polymethyl methacrylate.
• the layers may be colored or tinted as taught by commonly assigned US Patent 5,451 ,449. Table 1 below sets forth additional polymers which can be used to form the films of this invention.
• Poly(propylene) (density 0.9075 g/cm.sup.3) 1.5030
• Poly(ethylene) ionomer 1.51 poly(oxyethylene) (high molecular weight) 1.51-1.54 Poly(ethylene) (density 0.914 g/cm.sup.3) 1.51
• Nylon 6 Nylon 6,6: Nylon 6, 10 (moulding) 1.53 (Nylon-6-fiber: 1.515 transverse,
• Poly(styrene-co-acrylonitrile) (ca, 75/25) 1.57 Poly(oxycarbonyloxy-1 ,4-phenyleleneisobutylidene- 1.5702
• Polyvinyl benzoate 1.5775 poly(oxycarbonyloxy-1 ,4-phenylenebutylidene-1 ,4- 1.5792 phenylene)
• the multilayer films are usually made by a chill-roll casting technique in which melts of the thermoplastic resinous material from two or more extruders are collected by a feedblock which arranges them into a desired layered pattern.
• the very narrow multilayer stream flows through a single manifold flat film die with the layers 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 by using a different feedblock module. Suitable feedblocks are described, for instance, in U.S. Patent Nos. 3,565,985 and 3,773,882.
• the feedblocks can be used to form alternating layers of either two components (i.e. ABAB . . .
• the outermost layer or layers on each side of the sheet is thicker than the other layers so as to form a relatively thick skin.
• the resinous material used to form the skin may be one of the components which makes up the optical core, or a different polymer which is utilized to impart a desirable mechanical, heat sealing or other property, or a combination of these.
• the present film is made by a process diclosed in US Patent 3,801 ,429, incorporated herein by reference.
• iridescent films with unique color effects are achieved by laminating together at least two multilayered optical stacks as described above, in which each of the optical stacks is characterized as having one dominant wave length band which is reflected from the film. Accordingly, the iridescent film of the present invention is characterized as having at least two reflection peaks. While two multilayered optical stacks having distinct reflection peaks can be used to form the laminate film of this invention, it is further within the scope of this invention to laminate three or more multilayered optical stacks, each of which has a distinct reflection peak. In accordance with this invention, the multilayered optical stacks each have a distinct reflection peak which differs from the reflection peak of the other multilayered stack or stacks by at least 25nm. Differences in the wavelengths of the reflection peaks of each multilayered stack which form the laminate of this invention can also be at least about 50nm, 75nm, 100nm, and up to 300nm or more.
• each of the multilayer films are laminated or otherwise attached to each other can vary and can be accomplished by methods well known in the art of lamination.
• the multilayered optical stacks may be formed continuously as previously described and the separately formed optical stacks may be combined at a common feedblock while still in a molten state.
• the multilayered optical stacks can be formed separately, cooled, and then laminated into the multilayered films of this invention by means of a transparent adhesive, placed between the individual stacks.
• Transparent adhesives are well known in the art and include urethanes, epoxies, and acrylics. The particular adhesive does not form a part of the present invention so long as the adhesive is transparent and does not adversly affect the reflection peaks of the laminated films.
• a problem with forming multilayered films with distinct colors is the color uniformity of the individual optical stacks that are used to create the combination colors.
• Iridescent combination colors are very sensitive to variation in any of the optical stacks that generate the individual reflection peaks. Slight changes can result in very different reflection colors. Color uniformity of each optical stack is important in achieving the desired combination color.
• the development of single peak iridescent reflection films with uniform color allow the realistic combination of two or more distinct reflection peaks to create new iridescent colors that could not be created before, with the resultant combination color having satisfactory color uniformity across the entire web width. Methods of achieving color uniformity across the web are known and presently in practice.
• the present invention may be used in flexible and rigid decorative packaging.
• Flexible decorative packaging includes but is not limited to wrapping paper, ribbons, and bows.
• Rigid decorative packaging includes but is not limited to cosmetic and personal care containers such as for skin care products such as facial mask, UV protective lotion, liquid soap, and antimicrobial product; hair care products such as shampoo, conditioner, hair spray or fixative, and hair colorant; makeup products such as nail polish, mascara, eye shadow, and perfume; shaving cream, deodorant, baby oil, and dental products.
• the present film may also be used in printed and laminated board for use in packaging.
• the present invention may also be used in graphic applications such as book covers.
• the present film may also be used in vertical form and fill packaging which is a type of packaging equipment which feed the packaging film into a shaped area where it can be heat sealed in any of several ways and the package is then filled with something and sealed shut.
• the dimensions of the finished package are determined by the width of the film fed into the machine and the length of the bag is controlled by the speed and frequency settings at the sealing head. Numerous items may be packaged into a finished iridescent film pouch or bag in this way.
• the present film may also be used in fashion accessories such as sequins and threads.
• the present film may also be used in picture frame profile wrapping.
• the present invention may be sized reduced in some manner to form glitter particles. These particles are of various size and shape depending on the application. The size ranges from very small, approximately .004", to larger particles.
• the present film may also be used as a label for various containers.
• containers include but are not limited to cosmetic and personal care containers such as for skin care products such as facial mask, UV protective lotion, liquid soap, and antimicrobial product; hair care products such as shampoo, conditioner, hair spray or fixative, and hair colorant; makeup products such as nail polish, mascara, eye shadow, and perfume; shaving cream, deodorant, and baby oil.
• the containers may contain effect pigments such as titanium dioxide coated mica; iron oxide coated mica; iron oxide coated titanium dioxide coated mica as disclosed in commonly assigned US Patent 4,146,403 to Louis Armanini et al.; iron oxide or titanium dioxide coated glass as disclosed in commonly assigned US Patent 5,753,371 to William J.
• FIREMIST® pearlescent pigments (comprise calcium sodium borosilicate and titanium dioxide) commercially available from BASF Catalysts LLC; MAGNAPEARL® 1000 pearlescent pigment (comprises 70-80 weight percent mica and 20-30 weight percent titanium dioxide,) commercially available from BASF Catalysts LLC; MAGNAPEARL® 1100 pearlescent pigment (comprises 67-75 weight percent mica, 0.2-2.0 weight percent tin oxide, and 25-31 weight percent titanium dioxide) commercially available from BASF Catalysts LLC; MAGNAPEARL® 2100 pearlescent pigment (comprises 56.5-64.5 weight percent mica, 0.2-2.0 weight percent tin oxide, and 35.5-41.5 weight percent titanium dioxide) commercially available from BASF Catalysts LLC
• the present film may also be used in heat lamination to paperboard and other substrates.
• the film may be fed as a complete web into a nip, where under heat and pressure the film may be permanently adhered to a second substrate such as paperboard.
• This method offers a cost effective substitute for lamination processes requiring the use of adhesives to form the interlayer bond.
• Example 2 The combination of a multilayer coextruded light-reflecting film with a red interference color having a peak wavelength at 610nm and a multilayer coextruded light-reflecting film with a green interference color having a peak wavelength at 540nm were laminated together with a water-based urethane adhesive to generate an iridescent gold.
• Example 4 This model is optically equivalent to taking a multilayer coextruded light- reflecting film with a red interference color having a peak wavelength of 610nm and combining it with an iridescent film with a peak wavelength of 650nm.
• the generated shade is also red, but the combined film has a higher chroma than the single peak film.
• This model is optically equivalent to taking a multilayer coextruded light- reflecting film with a green interference color having a peak wavelength of 540nm and combining it with an iridescent film with a peak wavelength of 750nm.
• the generated shade is also green at normal incidence because the second peak is off in the IR region.
• the combined films have extended color travel that goes closer to red.
• This model is optically equivalent to taking a multilayer coextruded light- reflecting film with a violet interference color having a peak wavelength of 440nm and combining it with an iridescent film with a peak wavelength of 700nm.
• the generated shade is also violet at normal incidence because the second peak is off the IR region.
• the combined film color travels through red, orange and yellow.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Laminated Bodies (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

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• 2007
  • 2007-11-06 KR KR1020097011606A patent/KR20090083447A/ko not_active Application Discontinuation
  • 2007-11-06 CA CA002669808A patent/CA2669808A1/en not_active Abandoned
  • 2007-11-06 WO PCT/US2007/083749 patent/WO2008058115A2/en active Application Filing
  • 2007-11-06 JP JP2009536437A patent/JP2010509646A/ja active Pending
  • 2007-11-06 CN CNA2007800449964A patent/CN101553371A/zh active Pending
  • 2007-11-06 MX MX2009004924A patent/MX2009004924A/es not_active Application Discontinuation
  • 2007-11-06 EP EP07844900A patent/EP2084020A2/en not_active Withdrawn

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