WO2015183822A1

WO2015183822A1 - Lighting devices

Info

Publication number: WO2015183822A1
Application number: PCT/US2015/032460
Authority: WO
Inventors: Jeffrey J. Krueger; SR. James R. MORGAN; Iii Roger B. Quincy
Original assignee: Kimberly-Clark Worldwide, Inc.
Priority date: 2014-05-30
Filing date: 2015-05-26
Publication date: 2015-12-03

Abstract

A durable reflective film laminate is provided including a highly reflective layer of filled thermoplastic polymer, an antistatic layer, a pressure sensitive adhesive layer and a release sheet. The reflective film laminate provides greater than 92% reflectance of visible light and is capable is capable of withstanding the conditions associated with the maintenance and use of luminaires as well as the manufacturing conditions associated with the fabrication of luminaires and components thereof. Luminaires incorporating the durable reflective films and methods of making the same are also provided.

Description

LIGHTING DEVICES

This application claims the benefit of priority from U.S. Provisional Application No. 62/005,489 filed on May 30, 2014, the contents of which are incorporated herein by reference in their entirety for all purposes.

Field of Invention

The present invention relates to diffuse reflective films and illuminating devices utilizing the same.

Background

Diffuse reflectors are commonly employed in a wide variety of lighting devices such as, for example, direct and indirect lamps, recessed fixtures, down lights, as well as portable lighting devices including lamps, lanterns, flashlights, and so forth. One of the functions of the diffuse reflector is to provide a light scattering effect and increase the effective coverage area of the lighting device. In addition, in order to limit the extent to which the diffuse reflector reduces the overall light emission and efficiency, the reflector desirable provides a high degree of reflectivity in combination with the light scattering effect. In this regard, various films and/or coatings are known in the art for use as a diffuse reflector.

However, many films and coatings are susceptible to yellowing, cracking or otherwise deteriorating as a result of extended exposure to the conditions associated with the lighting device. Such defects can reduce the amount and/or quality of the light reflected. Similarly, many production processes associated with the manufacture of the lighting device require that the reflector be incorporated into the device, or a component thereof, early within the process such that the reflector must be capable of withstanding the thermal and/or mechanical stresses experienced in manufacturing without significant loss of the desired reflectance.

Accordingly, there remains a need for a reflector that is highly reflective and that is capable of withstanding various physical and/or environmental conditions without a significant loss of reflectance properties and including capable of withstanding (i) conditions associated with the long term use and maintenance of lighting devices and also (ii) thermo-mechanical stresses applied in association with the manufacture of lighting devices and/or components thereof.

Summary of the Invention

According to the present invention there is provided a luminaire having a housing, a light generator coupled to the housing, and an exit port through which light from the light generator exits the luminaire. The luminaire further includes a reflector panel comprising a support member and a reflective film laminate adhered thereto. The reflector panel is positioned within the luminaire with the reflective film laminate proximate to and/or facing the light generator. In certain aspects, the reflective film laminate can be adhered to a surface of the reflector support member proximate the light generator such that light from the light generator strikes the reflective film laminate and is at least partly redirected through the exit port. The reflector support member can be substantially rigid and, in certain aspects, can comprise metal and/or durable plastic material.

The reflective film laminate within the luminaire comprises (i) a white reflective film layer, (ii) a pressure sensitive adhesive layer and (iii) an antistatic film layer disposed between said white reflective film and said pressure sensitive adhesive layer. As applied in the luminaire, the pressure sensitive adhesive layer is adhered to the reflector support member. In certain aspects, the white reflective film can comprises between about 40% and about 70% thermoplastic polymer, such as a polyolefin, and also between about 30% and about 55% filler particles. In certain aspects, the filler particles can have a mean particle size of between about 150 and about 1000 nm. The white reflective film layer, in certain aspects, can comprise a film that is substantially non-porous or non-porous. In certain embodiments, the white reflective film layer may further include one or more anti-static agents. At a minimum, the reflective film laminate should provide a light reflectance of at least 92% at 550 nm and, desirably, provides an average light reflectance of at least 92% for all visible light.

In a further aspect, and in association with the manufacture of the reflective film laminate and/or luminaire, the reflective film laminate as described herein may further include a release sheet releasably attached to said pressure sensitive adhesive layer, wherein upon removal of said release sheet the pressure sensitive adhesive layer has a triboelectric static charge of less than about +/- 200V. In this regard, in association with the manufacture of a luminaire, the release sheet is removed from the reflective film laminate after which the pressure sensitive adhesive layer of the reflective film laminate is applied to the support member by the application of pressure. The reflective film laminate becomes fixedly adhered to the support member, having a peel strength in excess of 10 ounces /inch, thereby forming a reflector panel. The housing, light generator and reflector panel are assembled to form the luminaire. In this regard, the reflector panel is incorporated into and/or coupled to the housing such that light from said light generator strikes the reflective film laminate and is at least partly redirected through said exit port. In certain aspects, the panel member is substantially rigid and the reflector panel is shaped by the application of heat and/or pressure.

Brief Description of Drawings

Figure 1 is a cross-sectional view of a luminaire of the present invention incorporating a reflective film laminate. Figure 2 is a cross-sectional view of a reflective film laminate of the present invention.

Detailed Description

In reference to FIG. 1 , the present invention provides a luminaire 100 comprising a housing 102, a lamp 104 coupled to said housing 102, an exit port 104 through which light 106 from said lamp 104 exits the luminaire 100. A reflector 108 coupled to said housing 102 and positioned such that a substantial portion of light 106 from the lamp 104 strikes the reflector 108 and is redirected through the exit port 104. The reflector panel 108 can include a support member or panel member 1 10 and a reflective film laminate 150 adhered to the first side of the support member 110A proximate to the light generator 104.

A reflective film laminate 150 suitable for use in the manufacture of the luminaire of the present invention, as may be seen in reference to FIG. 2, can comprise (i) a white reflective film layer 152, (ii) an optional antistatic film layer 154, (iii) a pressure sensitive adhesive layer 156, and (iv) a release sheet 158. In one aspect, the antistatic film layer 154 can be disposed between the white reflective film layer 152 and said pressure sensitive adhesive layer 156. The pressure sensitive adhesive layer 156 of the reflective laminate 150 is adhered to the first side of the support member 110A after removal of the release sheet 158.

The light generator or lamp can comprise any one of numerous light producing elements as is commonly used in home and/or commercial settings. By way of example, suitable light generators or lamps include incandescent lamps (e.g. filament, halogen, etc.), gaseous discharge lamps (e.g. fluorescent, mercury vapor, metal halide, high and low pressure sodium, etc.), and electronic lamps (e.g. light emitting diodes). However, it is noted that for certain lamps that produce significant heat, e.g. certain halogen lamps, suitable polymers will need to be selected for use in the reflective laminate and/or a heat shielding element would need to be employed in the luminaire.

Numerous designs and structures for luminaires are known in the art and suitable for use with the present invention. Common components of a luminaire housing include various combinations of one or of the following: lamp holders, electrical coupling elements, ballast, lens, shade, mounting fixtures (e.g. wall or ceiling), trim and so forth. Examples of suitable luminaires include, but are not limited to, those described in US2364992 to Maurette; US4181930 to Mewissen et al.; US4285034 to Sullivan; US4660131 to Herst et al.; US4849867 to Glass et al.; US5097401 to Eppler et al.;

US2008/0278943 to Van Der Poel; US2013/0105832 to Peters et al., US2013/0286637 to Lay et al. and US2013/0294053 to Marquardt et al. In one aspect, the luminaire may optionally further include a lens or other light scattering cover 112 spanning the exit port 104 in order to further improve the coverage area of the luminaire and/or help limit the build-up of dust and other contaminants over the reflector and lamp. In addition, the housing provides support panels and/or extensions that can function as the support member for the reflective film laminate and/or that can hold and maintain the reflector in its desired position. In one aspect, the reflector can comprise, at least in part, support members or panels that also function as part of the electrical housing, mounting fixtures, or other elements of the luminaire. In certain aspects, the reflector(s) will be positioned within or about the luminaire in a spaced relationship to the lamp so as to redirect light outwardly from the lighting device through the exit port. The luminaire can contain one or more support members or panels for mounting and supporting the reflective film laminate. The support members for the reflector, in order to provide support to the reflective laminate, desirably comprise a firm material and in certain embodiments may comprise a substantially rigid or rigid material. The support member for the reflector may vary in shape and size in accordance with the overall shape and dimensions of the luminaire; in this regard the reflector support member or panel may be semi-circular, oval, parabolic, bell, rectangular, square, trapezoidal, or other shape as desired. In one aspect the reflector support members can comprise louvers positioned below the lamp proximate the exit port. In a further aspect, the reflector support members can comprise the outer walls of the luminaire or other portions of the housing. In still a further aspect, the reflector support members can comprise distinct support elements within the exterior walls of the luminaire positioned above and/or about the lamp. Desirably, the reflector, including the reflector support member and reflective film laminate, surrounds a substantial portion of the lamp and the exit port so as to maximize the light emitting efficiency of the device.

The support member for the reflector may comprise materials commonly employed in such lighting devices such as, for example, metal, particularly sheet metal (e.g. polished aluminum, steel, etc.), durable plastics (e.g. polycarbonates), composite fabrics and so forth. Often it will be desirable for the support member to comprise a rigid material that is non-planar. For example, the support member may comprise a shaped metal and/or thermoplastic member. In one aspect, the reflector panels may be made by a conventional process for making shaped aluminum alloy in which the aluminum alloy sheet is subjected to bright rolling to improve its reflectivity. Desirably the support member for the reflector is selected to comprise a reflective surface such as for example comprising polished aluminum or steel, white painted metal or white plastic. The bright rolled sheet may be non- planar and/or shaped by bending, embossing, or other deformation processes to help increase diffuse reflection. Further, shaped metal support members are typically buffed, chemically brightened, and/or anodized to improve their resistance to corrosion.

In order to further improve reflectance and efficiency of the luminaire, the support memebrs or panel members have applied thereto a highly reflective film laminate. In this regard, the luminaire of the present invention includes a support member 110 having thereon a reflective film laminate 150 comprising a white reflective film layer 152, an adhesive layer 156 and a charge dissipative layer or antistatic layer 154. The adhesive layer 156 is applied to and permanently adhered to the first side 11 OA of the reflector panel 110 proximate the lamp. The reflective film laminate 150 may be applied to the support member 110 either before or after the panel is shaped and/or cut to form the final desired dimensions. In addition, the reflective film laminate may likewise be cut to the desired dimensions so as to substantially correspond with the support member either prior to or after application of the laminate to the support member. In one aspect, the reflective laminate may be die cut so as to correspond to the dimensions of the support member and/or to have discrete apertures therein that substantially align with and corresponding to individual lamps, lamp holders or other elements of the luminaire. However, in order to aid processing and manufacture, it will often be desirable to have the reflective laminate cut to the desired shape and size prior to adhering the reflective laminate to the support member. In certain embodiments it will be desirable for the reflective film laminate 150 to be coextensive with the reflector support member 110 and in particular for the reflector support member 110 and the reflective film laminate 150 to be coterminous, or substantially coterminous as shown in Figure 1. Further, in certain embodiments, the support member may extend outwardly beyond the peripheral edges of the reflective film laminate such that the reflective film laminate overlaps only a portion of the support member. Additional details regarding the reflective laminate are provided herein below.

The reflective film laminate of the present invention includes at least one highly reflective film layer. In reference to Figure 2, the reflective film laminate 150 and white reflective film 152 desirably have a reflectance greater than about 92% for light at 550 nm wavelength and more desirably an average reflectance greater than about 92% for all visible light. The term "visible light", as used herein, is intended to mean electromagnetic radiation in the visible light portion of the spectrum having a wavelength between 400 nm to 700 nm. In a further aspect, the reflective film laminate and white reflective film layer desirably have a reflectance greater of at least about 94% for light at 550 nm wavelength and more desirably has an average reflectance of at least about 94% for all visible light.

In still a further aspect, the reflective film laminate and white reflective film layer desirably have a Total Reflectance greater than about 92% and still more desirably greater than about 94% or 95%. As used herein "Total Reflectance" means the % of light reflected as measured by a Baumgartner sphere reflectometer. The Baumgartner sphere reflectometer consists of an integrating 4 inch diameter sphere, light source, and a photodiode. The sample is placed at the sample port of the integrating sphere. A 5/16 inch diameter collimated beam of light that is directed onto the sample; the reflectometer has an integrating, collimated beam with a 45 degree angle of incidence, a CIE illuminant A incandescent source and a magnesium carbonate working standard (for calibration). The total reflected light, integrated by the sphere, is measured by the photodiode mounted in the sphere wall. The collimated light source is then rotated so that the light is incident on the sphere wall, and a second reading is taken. The sample is in place during both measurements, so that the effect on both readings of the small area of the sphere surface it occupies is the same. The ratio of the first reading to the second is the reflectance of the sample for the conditions of the test. Six reflectance measurements were recorded for the sample. The high and low values were discarded and the remaining four readings were then averaged.

The gloss of the exposed portion of the reflective film laminate and/or the side of the white reflective film layer facing the lamp, desirably has a gloss less than 10% and still more desirably a gloss less than 5% and even more desirably less than 3%. As used herein "gloss" means the degree of specular gloss measured at 60° in accordance with ASTM D523 (2014).

In addition, desirably the composition of the reflective film laminate and white reflective film is selected such that it can withstand common cleaning techniques and, in particular, that the reflective film laminate and white reflective film layer is resistant to cleaning chemicals such as aqueous cleaners containing surfactants, ammonia, bleach, and alcohol. In addition, the reflective film laminate and white reflective film of the present invention desirably has good UV stability and, in this regard, loses less than about 2% of Total Reflectance after 1000 hours (at 85 C and 85% humidity) exposure to a Xeon Arc as set forth in ASTM G155-13.

The white reflective film layer can comprise any one of various materials so long as the film layer provides the resulting laminate with the desired degree of durable reflectivity. In one aspect the film can comprise a thermoplastic polymer and a filler. Suitable thermoplastic polymers for use in the reflective film include melt-extrudable polyolefins, polyesters, polyamides, polyurethanes and polyphenylene sulfides. More specifically suitable melt-extrudable polymers include polyethylenes, polypropylenes, polybutylenes, ethylene-cyclic olefin copolymers, nylon-6, nylon-6,6, nylon-6,10, nylon-6, 12, polyethylene terephthalate, poly lactic acid, polycarbonate, polystyrene, and so forth. Of those, preferred are olefin-based resins. Suitable propylene-based polymers include propylene homopolymer, isotactic or syndiotactic polypropylene or polypropylene of other stereospecificity; and propylene-based copolymer with any other alpha-olefins such as ethylene, butene-1 , hexene-1 , heptene-1 ,4-methylpentene-1. Suitable polyethylenes include high-density polyethylenes, low-density polyethylenes, linear low-density polyethylenes; inclusive within such polymers are copolymers of ethylenes and alpha-olefins, polypropylenes, and other monomers.

Suitable fillers include both organic and inorganic particles. By way of non-limiting example suitable inorganic filler particles include metal salts, metal hydroxides and metal oxides, the latter often being preferred. Specific examples include, but are not limited to, barium sulfate, calcium sulfate, magnesium sulfate, aluminum sulfate, barium carbonate, calcium carbonate, magnesium chloride, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, zinc oxide, magnesium oxide, titanium oxide, alumina and silica. Of the aforesaid inorganic fillers, titanium dioxide, calcium carbonate, barium sulfate, and magnesium hydroxide are often preferable for ease of dispersion and ability to more highly load the polymer. In addition, organic filler particles such as those derived from clays such as calcium silicate, cements, zeolites and talc are also usable. In certain embodiments the filler particles may optionally be coated with a fatty acid, such as stearic acid or behenic acid, and/or other material in order to facilitate the free flow of the particles (in bulk) and their ease of dispersion into the polymer.

The filler particles can have a mean particle size of between about 100 and 2000 nm and desirably have a mean particle size between about 150 - 1000 nm and still more desirably a mean particle size between about 150 - 500 nm. In a particular embodiment, the mean particle size can be about 200 nm. In certain aspects, it is also desirable that 90% of the particles have a particle size less than 8000 nm and still more desirably less than 5000nm, 3000nm and even less than 2000 nm.

Particle sizes can be measured on a Beckman-Coulter LS 13 320 laser-diffraction particle size analyzer or other equivalent device. The amount of thermoplastic polymer utilized in the white reflective film layer can comprise, by weight of the white reflective film layer, between about 30% and about 80% and desirably comprises between about 40% and about 75% and still more desirably between about 50% and 65%. The filler particles utilized in the white reflective film layer can comprise, by weight of the white reflective film layer, between about 70% and about 20% and desirably comprises between about 30% and about 55% and still more desirably between about 30% and 45%.

In addition, the white reflective film may optionally include other additives such as, for example, fluorescent brighteners, light (UV) stabilizers, antistatic agents, dispersants, lubricants, desiccants, antioxidants, heat aging stabilizers, anti-blocking agents, bonding agents, and so forth. Typically such additives will be present in amounts less than about 10% by weight of the white reflective film and desirably are present in amounts between about 0.01% and about 5% by weight of the white reflective film.

Internal antistatic additives are commonly employed to improve handling and converting of the film. With respect to antistatic agents, suitable additives include monomeric, oligomeric, or polymeric materials that can be processed into polymer resins in order to aid in the dissipation of electrical charges on or within the film. Examples of monomeric antistatic agents include glycerol monostearate, glycerol distearate, glycerol tristearate, ethoxylated amines, primary, secondary and tertiary amines, ethoxylated alcohols, alkyl sulfates, a Ikyla rylsu Ifates, alkylphosphates, alkylaminesulfates, alkyl sulfonate salts such as sodium stearyl sulfonate, sodium dodecylbenzenesulfonate or the like, quaternary ammonium salts, quaternary ammonium resins, imidazoline derivatives, sorbitan esters, ethanolamides, betaines, or the like, or combinations comprising at least one of the foregoing monomeric antistatic agents. Polymeric antistatic agents include certain polyesteramides polyether- polyamide (polyetheramide) block copolymers, polyetheresteramide block copolymers,

polyetheresters, or polyurethanes, each containing polyalkylene glycol moieties polyalkylene oxide units such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

Numerous polymeric antistatic agents are commercially available including, for example, Sanyo PELESTAT NC 6321 , Arkema PEBAX MV1074 or MH1657, and BASF IRGASTAT P18.

Various UV stabilizers are known and suitable for use in the white reflector film layer including, for example, UV stabilizers such as steric-hindered amine stabilizers, metal chelate stabilizers, benzotriazole-type, benzophenone-type light stabilizers and combinations thereof. Suitable hindered amine stabilizers are discussed in US5200443 to Hudson and examples of such amines are, BASF TINUVIN 622 which is dimethyl succinate polymer with 4-hydroxy-2,2,6,6, tetramethyl-1- piperidineethanol and CHIMASSORB 944 which is poly[[6-[(1 , 1 ,3,3, tetramethyl butyl)amino]-s- triazine-2,4-diyl][[(2,2,6,6,-tetramethyl-4-piperidyl) imino]hexamethylene [(2,2,6,6-tetrametyl-4- piperidyl) imino]] and CHIMASSORB 119 which is 1 ,3,5-Triazine-2,4,6-triamine, N,N-1 ,2- ethanediylbisN-3-4,6-bisbutyl(1 ,2,2,6,6-pentamethyl-4-pipendinyl)amino-1 ,3,5-triazin-2-ylaminopropyl- N,N-dibutyl-N,N-bis(1 ,2,2,6,6-pentamethyl-4-piperidinyl). An example of hydroxybenzoate stabilizers is 2,4-di-t-butylphenyl ester and those described in US3206431 to Doyle. Metal chelate stabilizers are also known in the art and believed suitable for use in the present invention, particularly those comprising nickel complexes. Hindered amine light stabilizers UV stabilizers are particularly well suited for use in the used in the present invention.

Antioxidants and heat stabilizers include, for example, steric-hindered phenol-type, or phosphorus-containing, amine-type stabilizer and combinations thereof. Chroman derivatives having an extended carbon chain such as, for example, tocopherols (vitamin-E), including alpha -tocopherol or 2,5J,8-tetramethyl-2-(4',8',12'-trimethyltridecyl)-6-chromanol are examples of suitable hindered phenol stabilizers. Various hindered phenols stabilizers are commercially available from BASF including IRGANOX E 217, 1076, 1010, B900, B921. Phosphite stabilizers are also commercially available from BASF including IRGAFOS(R) 168. Desiccants suitable for use in the white reflective film include zeolites and calcium oxide.

The white reflective film layer can be formed by a wide variety of processes well known to those of ordinary skill in the art. Two particularly advantageous processes are cast film extrusion processes and blown film extrusion processes. Generally speaking, a substantially homogeneous blend of the polymer and filler is melted and fed into polymer extruders and extruded into nip or chill rollers, one of which may be patterned so as to impart an embossed pattern to the newly formed film. In this regard, the film is desirably patterned to a minor extent in order to help reduce gloss. Films formed by this process can be non-porous or substantially non-porous. The white reflective film may be a monolithic film or, alternatively, may comprise a multi-layer film such as may be formed by co- extrusion. In addition, it is also possible to employ a plurality of separately formed superposed white reflective films to achieve the desired film thickness and/or reflectivity of the white reflective film layer.

In addition, micro-porous films are also suitable for use with the present invention. Filled films, such as described above, can be stretched to generate the extensive formation of pores within and throughout the film. In this regard the formed film can be directed from the extrusion film apparatus to a film-stretching unit and may be stretched mono-axially or bi-axially including through the use of simultaneous, sequential and/or incremental stretching techniques. By way of example a mono-axial stretching unit may employ a plurality of stretching rollers operating at increasing rotational speeds thereby progressively stretching the film in the machine direction of the film as it passes through successive pairs of rollers. The film may be stretched, for example, greater than about 2X to about 8X its original dimension. The film may be stretched at ambient or heated conditions and may be annealed prior to or after the stretching steps. Both microporous and substantially non-porous films are suitable for use with the present invention.

The reflective film desirable has a basis weight of between about 50 g/m² and about 600 g/m². In certain embodiments, the reflective film can have a basis weight of between about 150 - 450 g/m² and in still further embodiments can have a basis weight of between about 150 - 300 g/m². As noted above, various suitable reflective films are known and suitable for use in the present invention. By way of example only, reflective films suitable for use as part of the reflective laminate include, but are not limited to, those described in JP3784849 to Sugiyama, US5261899 to Visscher et al., US5991080 to Kohta et al., US6497946 to Kretman et al., US6914719 to Koyama et al., US7548372 Ueda et al., US2005/01 12351 to Laney et al.

The reflective laminate may also include an antistatic layer situated between the white reflective film layer and the outer adhesive layer. The antistatic coating is desirably applied to provide sufficient charge dissipative functionality to the reflective laminate such that an electrostatic charge of less than +/- 200V is generated after removal of the release liner. The electrostatic charge differential is determined, in accordance with the triboelectric charge accumulation test ESD ADV 1 1.2 (1995), on the adhesive layer of the reflective laminate immediately after removal of the release sheet. The antistatic layer typically comprises (i) a conductive material and (ii) a binder resin. The antistatic coating can negatively impact reflectivity and therefore the thickness of the antistatic layer is desirably employed only to the extent necessary to achieve the desired charge dissipative properties; as will be appreciated the particular thickness will vary with the selected conductive component(s), % composition of the conductive component(s), selected binder resin and so forth. Further, in order to reduce and/or limit the negative impact of the antistatic layer on the reflectivity of the reflective laminate, desirably the antistatic layer is substantially transparent to the naked eye.

Various organic or inorganic electroconductive substances or various types of antistatic agents can be used as the antistatic component of the reflective laminate. Examples of conductive antistatic agents include cationic antistatic agents having a cationic functional group such as a quaternary ammonium salt, pyridinium salt, primary amine group, secondary amine group and tertiary amine group; anionic antistatic agents having an anionic functional group such as a sulfonate ester, sulfate ester, phosphonate ester and phosphate ester; amphoteric antistatic agents such as alkyl betaines and derivatives thereof, imidazoline and derivatives thereof and analine and derivatives thereof; nonionic antistatic agents such as amino alcohols and derivatives thereof, glycerin and derivatives thereof and polyethylene glycol and derivatives thereof; and ionic electroconductive polymers obtained by polymerizing or copolymerizing a monomer having a cationic, anionic or amphoteric ionic

electroconductive group. In addition, various quaternary antistatic agents are described in more detail in US5187214 to Govindan, US2012/0202055 to Kataoka, and US2013/183456 to Kim.

Suitable conductive polymers include, but are not limited to, polyanilines, polypyrroles, polythiophenes polyethylene imines, polyselenophenes, allylamine-based compounds, and derivatives and mixtures thereof. Such conductive polymers may be used in a cationic form in combination with one or more polyanions. Polyanions may be selected, without limitation, from polymeric carboxylic or sulfonic acid anions (polyacids) and mixtures thereof. Suitable examples thereof include, but are not limited to, polystyrene sulfonate, polyvinyl sulfonate, polyacrylate, polymethacrylate, polymaleate anions, as well as anions of copolymers obtained by copolymerizing at least one acid monomer such as acrylic, methacrylic, maleic, styrene sulfonic, or vinyl sulfonic acid, with at least one other acid or nonacid monomer. Specific examples of such antistatic agents include, but are not limited to, those described in US5716550 to Gardner et al., US5093439 to Epstein et al., US5674654 to Zumbulyadis et al., US5575898 to Wolf et al., US5403467 Jonas et al., US5300575 to Jonas et al., US6586041 to Ibar, and US2010/003508 to Arrouy et al.

Conductive polymers may be substituted with various functional groups, especially with hydrophilic groups, preferably ionic or ionizable groups, such as COOH, SO3H, NH2, ammonium, phosphate, sulfate, imine, hydrazino, OH, SH groups or salts thereof. Such functional groups make it easier to prepare an aqueous precursor composition of the antistatic coating by making conductive polymers more compatible with water and thus more readily soluble or dispersible in the precursor composition and more uniformly distributed throughout the resulting antistatic film. Additional antistatic agents believed suitable for use in the present invention include trineoalkoxy monoamino zirconates and/or trineoalkoxy monosulfonyl zirconates such as described in US5659058 to Monte and polyampholyte polymer and ampholyte polymers such as described in US4596668 to Berbeco.

The antistatic layer also comprises at least one binder. The binder may be any material that may be suitably used to form a film and desirably comprises a polymeric material. In one aspect, the binder material may comprise a polymer such as described above in relation to the reflective film layer. In certain aspects, the binder resin can be one type or two or more types of resins. Various types of resins are believed suitable for use with the present invention including, for example, thermosetting resins, ultraviolet curable resins, electron beam curable resins and two-component mixed resins. The selection of the binder resin will vary with respect to the selected antistatic agent, the properties of the opposed reflective and adhesive layers, as well as the desired film formation method (e.g. suitable solvent systems). Of particular importance, the binder should be compatible with the antistatic agent and should not significantly degrade the desired conductive properties of the same.

Non-thermoplastic binders of the anti-static layer are desirably soluble or dispersible in water or in an aqueous composition such as a water-alcohol composition. Suitable water-soluble or water- dispersible binders include homopolymers or copolymers from the following monomers: styrene, vinylidene chloride, vinyl chloride, alkyl acrylates, alkyl methacrylates, (meth)acrylamides, homopolymers or copolymers of the polyester, poly(urethane-acrylate), poly(ester-urethane), polyether, polyvinyl acetate, polyepoxide, polybutadiene, polysilazne, polyacrylonitrile, polyamide, melamine, polyurethane, polyvinyl alcohol type, their copolymers, and mixtures thereof.

In one aspect, the antistatic layer may be formed by applying the antistatic agent and binder in liquid form, together with the appropriate solvents, over the reflective film and thereafter dried and/or polymerized to form a substantially uniform coating or film layer. The antistatic layer precursor may be applied over the white reflective film by one or more methods known in the art such as, for example, extrusion coating, gravure coating, spraying, printing, wire-rod coating, etc. Desirably the liquid precursor of the antistatic coating will comprises a solution or dispersion of at least one conductive polymer, a binder, and an optional cross-linking agent, in an aqueous or organic solvent, or in a mixture of solvents. Commonly employed solvents, used with or without water, include the following alcohols: methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1 -ethyl-1 -propanol, 2-methyl-1- butanol, 1 -methoxy-2-propanol, n-hexanol, cyclohexanol, ethyl cellosolve (monoethoxy

ethyleneglycol), ethyleneglycol. Once applied to the surface of the reflective film, the precursor may be treated in the appropriate manner so as to achieve the desired polymerization such as through heating, UV irradiation, e-beam treatment or other treatments.

To further increase adhesion, the antistatic layer may optionally include one or more crosslinking agents which are likewise soluble or dispersible in the selected solvents. Suitable crosslinking agents are well known in the art and are capable of reacting with the functional groups of the binder. Examples include, but are not limited to, polyfunctional aziridines, methoxyalkylated melamine or urea resins, e.g. methoxymethylated melamine/formaldehyde resins and

urea/formaldehyde resins, epoxy resins, carbodiimides, polyisocyanates, triazines and blocked polyisocya nates.

In addition, to further promote strong adhesion between the white reflective film and the antistatic coating, prior to application of the antistatic coating precursor the surface of the reflective film may be treated or have a tie layer applied there. For example, in one aspect the inner layer of the reflective film may, prior to application of the antistatic coating precursor, be treated with corona discharge treatment, plasma treatment, ultraviolet radiation treatment, acid treatment or alkaline treatment. Alternatively, the surface of the reflective film may include a tie layer or adhesion-promoting agent layer such as, for example, a thin coating formed from acrylate or methacrylate monomers such as glycidyl acrylate, or butadiene, vinyl halide or maleic anhydride monomers, or from silanes or siloxanes such as aminosilanes.

An adhesive layer is formed over the reflective film layer and in certain aspects over the antistatic layer. The adhesive is selected to provide the appropriate adhesion and cohesion properties as between the reflective film laminate and the support member of the lighting device. Desirably the adhesive provides a permanent bond as between the reflective film laminate and the support member of the lighting device. In this regard, the selected adhesive desirably provides adequate adhesion between the support member 1 10 and reflective laminate 150B such that it has a peel strength in excess of 10 ounces /inch, and desirably a peel strength of at least about 20 ounces/inch, and still more desirably in excess of 30 ounces/inch or 40 ounces/inch. The peel strength is determined according to ASTM D3330 (2010). Pressure sensitive adhesives, which allow a permanent bond to the substrate with the application of weak to modest applied pressure, are particularly well suited for use with the present invention. Desirably a pressure sensitive adhesive is selected so as to be capable of providing a permanent attachment between the reflective laminate and luminaire and that is resistant to the loss of adhesion due to exposure to heat, humidity and light. Numerous adhesives suitable for use in the present invention are known and the art and can be used in connection herewith. Various pressure sensitive adhesives suitable for use with the present invention include, but are not limited to, those described in US5721289 to Karim et al., US5314944 to Chao, US7696278 to Kim et al., US2009/0163660, and US2011/0104488 to Mussig et al. The adhesive layer may be applied in an amount necessary to achieve the desired peel strength. In certain embodiments, the adhesive layer may have a thickness of between about 0.2 mil to about 5 mil, and in in still other embodiments may have a thickness of about 0.5 to about 2 mil. Further, in order to reduce the potential negative impact of the adhesive layer on the reflectivity of the reflective laminate, desirably the adhesive layer is substantially transparent.

The adhesive layer can be formed over the reflective film layer and/or the antistatic layer by one or methods known in the art such as, for example, extrusion coating, gravure coating, spraying, printing, wire-rod coating, etc. The adhesive may be applied as a substantially continuous coating covering the entire surface of the antistatic coating layer or, alternatively, may be applied over less than the entire surface of the antistatic layer. In certain embodiments, the adhesive may be applied in a continuous or discontinuous pattern such as, for example, in sinusoidal patterns, lattice patterns, dot patterns, etc. In addition, once applied to the antistatic layer, the adhesive can be further acted upon to achieve the desired adhesion and cohesion properties such as by drying, cross-linking, etc.

In one aspect of the present invention, the reflective laminate may include a release liner 158 protecting the adhesive surface of the laminate in order to allow for further converting and/or shipping prior to application to the luminaire or a component thereof. Optionally, the reflective laminate is provided on a roll with the adhesive surface protected by one release liner having a release surface on both of its major sides. If the reflective laminate is provided in sheet form, a release liner 158 may be provided on the adhesive surface having only one release surface in face-to-face relation with the pressure sensitive adhesive layer 156. Any one of various known release liners are believed suitable for protecting the pressure sensitive adhesive layer prior to adherence to the luminaire. Typically such release liner will be a paper or plastic film having a low surface energy polymeric film such as may be formed by a silicone or fluoropolymer release surface. Specific examples of release liners include, but are not limited to, those described in US4386135 Campbell et al., US5143570 Freedman, US5942591 Itoh et al., and US6824828 to Su et al.

Still further additional features, layers and various constructions known in the art are suitable for use in connection with the present invention. Thus, while the invention has been described in detail with respect to specific embodiments and/or examples thereof, it will be apparent to those skilled in the art that various alterations, modifications and other changes may be made to the invention without departing from the spirit and scope of the same. It is therefore intended that the claims cover or encompass all such modifications, alterations and/or changes. In addition, as used herein the term "comprising" or "including" are inclusive or open-ended and do not exclude additional unrecited elements, compositional components, or method steps. Accordingly, the terms "comprising" or "including" encompass the more restrictive terms "consisting essentially of" and "consisting of."

Claims

What is claimed is:

1. A luminaire comprising:

a housing having a reflector support member and a reflective film laminate adhered to said reflector support member;

a light generator coupled to said housing;

an exit port through which light from said light generator exits the luminaire;

wherein said reflective film laminate comprises (i) a white reflective film layer, (ii) a pressure sensitive adhesive layer and (iii) an antistatic film layer disposed between said white reflective film and said pressure sensitive adhesive layer, and further wherein said pressure sensitive adhesive layer is adhered to said reflector support member.

2. The luminaire of claim 1 wherein said reflective film laminate is adhered to a surface of said reflector support member proximate the light generator and whereby light from said light generator strikes said reflective film laminate and is at least partly redirected through said exit port.

3. The luminaire of claim 1 wherein said reflector support member is substantially rigid and is selected from the group consisting of metal and plastic.

4. The luminaire of claim 1 wherein the adhesion between the reflector support member and reflective film laminate has a peel strength in excess of 10 ounces /inch.

5. The luminaire of claim 1 wherein said white reflective film comprises between about 40% and about 70% thermoplastic polymer and also between about 30% and about 55% filler particles having a mean particle size of between about 150 and about 1000 nm.

6. The luminaire of claim 5 wherein said white reflective film comprises filler particles having a mean particle size of between about 150 and about 500 nm.

7. The luminaire of claim 5 wherein said white reflective film is selected from the group consisting of substantially non-porous films and non-porous films.

8. The luminaire of claim 5 wherein said white reflective film layer further comprises an antistatic agent.

9. The luminaire of claim 5 wherein the reflective film laminate has a reflectance greater than about 94% for light at 550 nm wavelength.

10. The luminaire of claim 6 wherein the reflective film laminate has a Total reflectance greater than 94%.

11. A method of making a luminaire comprising the steps of:

(i) providing a support member;

(ii) providing a reflective film laminate including (a) a white reflective film layer comprising a thermoplastic polymer and selected from the group consisting of microporous films and particle filled films; (b) an antistatic film layer adjacent to said white reflective film layer; (c) a pressure sensitive adhesive layer adjacent said antistatic film layer wherein said antistatic film layer is positioned between said white reflective film layer and said pressure sensitive adhesive layer; and (d) a release sheet releasably attached to said pressure sensitive adhesive layer,

(iii) removing said release sheet from said reflective laminate wherein upon removal of said release sheet the pressure sensitive adhesive layer has a triboelectric static charge of less than about +/- 200V;

(iv) applying the pressure sensitive adhesive layer of the reflective film laminate to said support member thereby forming a reflector panel; and

(v) assembling the luminaire together with said reflector panel whereby said luminaire comprises a housing incorporating said reflector panel, a light generator coupled to said housing and an exit port, and wherein the reflector panel is positioned such that light from said light generator strikes said reflective laminate and is at least partly redirected through said exit port.

12. The method of claim 11 wherein said support member is substantially rigid and selected from the group consisting of metal and thermoplastic polymer and further wherein said reflector panel is shaped by the application of heat and/or pressure.

13. The luminaire of claim 1 1 wherein the support member and reflective laminate have a peel strength in excess of 10 ounces /inch.

14. The method of claim 11 wherein said white reflective film comprises between about 30% and about 80% thermoplastic polymer and also between about 20% and about 70% filler particles having a mean particle size of between about 100 and 2000 nm.

15. The method of claim 11 wherein said white reflective film comprises between about 40% and about 70% thermoplastic polymer and also between about 30% and about 55% filler particles having a mean particle size of between about 150 and about 1000 nm.

16. The method of claim 11 wherein said white reflective film comprises filler particles having a mean particle size of between about 150 and about 500 nm.

17. The method of claim 11 wherein said white reflective film is selected from the group consisting of substantially non-porous films and non-porous films.

18. The method of claim 11 reflective film laminate has an average reflectance for all visible light greater than 92%.