JP5405917B2 - Thermoplastic resin film used as a reflective film for LED lighting - Google Patents

Description

  The present invention relates to a thermoplastic resin film used as a reflection film for illumination using an LED as a light source (hereinafter referred to as a unit “LED illumination”).

  A light emitting diode, that is, an LED (Light Emitting Diode), is a semiconductor element that emits light when a voltage is applied in the forward direction, and is a semiconductor element that emits light using electroluminescence as a light emission principle. With the development of technology for extending the life of LEDs and improving light emission efficiency, illumination using LEDs as a light source has been positioned as a next-generation energy-saving illumination and has attracted attention.

  The lifetime of the LED is longer than that of a conventional incandescent bulb, and the element itself can be used semipermanently. Most of the cases where the LED becomes unusable are due to the metal oxidation or deterioration of the LED electrode portion, the internal metal member being damaged or the wiring being disconnected due to overheating or impact. For this reason, LED is very promising as an energy-saving light source. Further, the light emission color of the LED varies depending on the material used, and the light emission from the infrared region to the visible light region and the ultraviolet region is possible, and can correspond to illumination of various colors.

  However, for the reflective member corresponding to LED lighting, a reflective plate in which a white pigment or the like is applied on a metal plate, a mirror-finished metal reflective plate, and a white plastic reflective member by integral molding have been used so far. R & D has not been done enough. For this reason, the performance (illuminance) as a whole of LED lighting has room to improve further by improvement of a reflecting member.

Japanese Patent No. 3498290 Japanese Patent No. 4096927

  This invention makes it a subject to provide the thermoplastic resin film used as a reflective film of LED lighting which can fully utilize the performance of an LED light source, and can improve the illumination intensity as the whole LED lighting containing a reflection member. .

That is, the present invention is a thermoplastic resin film containing fine voids and the phosphor, the thermoplastic resin film is made of one or more layers, the composition of the thermoplastic resin containing fine voids A light reflection layer made of a material, the light reflection layer contains 4 to 40% by weight of a phosphor based on the weight of the light reflection layer, and the void volume ratio of the light reflection layer is 35 to 75%. It is a thermoplastic resin film characterized by being used as a reflection film for illumination using an LED as a light source.

ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic resin film used as a reflective film of LED lighting which can fully utilize the performance of an LED light source and can improve the illumination intensity as the whole LED lighting containing a reflection member can be provided. .
The thermoplastic resin film of the present invention is suppressed in discoloration over time, and is particularly suitable as a reflection film for lighting for indoor or outdoor lighting in buildings.

  Hereinafter, the present invention will be described in detail.

[Thermoplastic resin film]
The thermoplastic resin film used as the reflective film of the LED lighting of the present invention is a single layer film made of a thermoplastic resin or a laminated film made of two or more layers.
In the case of a single layer film, the fine voids and the phosphor are contained in the same layer.
In the case of two or more layers, the fine void and the phosphor are preferably contained in different layers, but may be contained in the same layer.

  In any case, in the thermoplastic resin film, the void volume ratio of the layer containing fine voids is preferably 30 to 80%, more preferably 35 to 75%, and particularly preferably 38 to 70%. When the void volume ratio is within this range, high light reflectance can be obtained. The light reflectance of the thermoplastic resin film is preferably 96% or more, and more preferably 97% or more.

  Is the thermoplastic resin film formed by stretching an unstretched film made of a composition of a thermoplastic resin and a material incompatible with the thermoplastic resin and peeling the two at the interface to form fine voids? It is preferable that a void is formed by forming a composition in which a foamable substance is blended with a thermoplastic resin into a sheet shape and foaming.

[Thermoplastic resin]
As the thermoplastic resin used for the thermoplastic resin film, for example, polyester, polycarbonate, and polyolefin can be used. Of these, polyesters, particularly thermoplastic aromatic polyesters, are preferable from the viewpoints of shape stability under high heat and high humidity and ease of film formation.

  Examples of the thermoplastic aromatic polyester include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. These polyesters may be copolymerized with a copolymer component. The ratio of the copolymerization component is, for example, 20 mol% or less.

[Incompatible materials]
As the incompatible substance used for forming the void, for example, resins, organic particles, and inorganic particles that are incompatible with the thermoplastic resin of the film can be used.

[Incompatible resin]
The incompatible resin used for forming the void varies depending on the thermoplastic resin of the thermoplastic resin film. When polyester is used as the thermoplastic resin of the thermoplastic resin film, examples of incompatible resins include polyolefin and polystyrene, specifically, for example, poly-3-methylbutene-1, poly-4-methylpentene-1, and polyethylene. , Polypropylene, polyvinyl-t-butane, 1,4-trans-poly-2,3-dimethylbutadiene, polyvinylcyclohexane, polystyrene, polyfluorostyrene, cellulose acetate cellulose propionate, polychlorotrifluoroethylene can be used. . Particularly preferred are polypropylene and polymethylpentene. Since these polypropylenes and polymethylpentenes are highly transparent, they are optimal because they can suppress light absorption and improve reflectance.

  The incompatible resin is used, for example, 5 to 30% by weight, preferably 8 to 25% by weight, particularly preferably 10 to 20% by weight per 100% by weight of the resin composition of the thermoplastic resin layer forming the void. By using in this range, it is possible to stably form a film while forming a sufficient amount of fine voids in the film.

[Inorganic and organic particles]
As the inorganic particles, inorganic particles can be used, and white pigment or inorganic phosphor particles are used. From the viewpoint of obtaining high reflection performance, it is preferable to use a white pigment. As the white pigment, for example, titanium oxide, barium sulfate, calcium carbonate, silicon dioxide particles, preferably barium sulfate particles are used. The barium sulfate particles may take a plate shape or a spherical shape, but may be particles of any shape. By using barium sulfate particles, particularly good light reflection performance can be obtained.
As the organic particles, polymer particles can be used. For example, particles of acrylic, cross-linked polystyrene, polyolefin, particularly polymethylpentene can be used.

  When organic particles or inorganic particles are used as incompatible substances for forming voids, the average particle size is preferably 0.3 to 10 μm, more preferably 0.4 to 8 μm, and particularly preferably 0.5 to 5 μm. Use one with a diameter. Use of particles having an average particle diameter in this range is preferable because aggregation hardly occurs, fine voids are formed, and a film can be formed without breaking.

  When inorganic particles or organic particles are used, the amount is preferably 31 to 60% by weight, more preferably 35 to 55% by weight, and particularly preferably 37 to 50% by weight per 100% by weight of the resin composition of the layer forming the void. By containing in this range, a film having high reflectance and less deterioration due to ultraviolet rays can be obtained by stable film formation.

[Phosphor]
The thermoplastic resin film in the present invention contains a phosphor. The phosphor may be contained in a layer containing fine voids, or may be contained in a layer different from the layer containing fine voids. The layer may be laminated by coextrusion on a layer having fine voids, or may be applied to a layer having fine voids. Note that the layer having fine voids and the layer containing the phosphor may be laminated in direct contact with each other or may be laminated via another layer. Examples of the “other layer” include a support layer which is provided to support a layer containing fine voids and does not contain voids or has a low void volume ratio.

As the phosphor in the present invention, either an inorganic phosphor made of an inorganic substance or an organic phosphor made of an organic substance can be used. Inorganic phosphors are preferred because they are not easily decomposed by ultraviolet rays when used in the coating layer.
The phosphor preferably has an emission wavelength of 380 to 780 nm and an excitation wavelength of 350 to 650 nm. By having the emission wavelength and the excitation wavelength in this range, high illuminance can be obtained.

In inorganic phosphors, phosphors satisfying the requirements for the excitation wavelength and emission wavelength described above are alkaline earth metal sulfides having a rock salt crystal structure, such as zinc sulfide (ZnS), strontium sulfide (SrS), and yttrium oxide. A phosphor containing (Y ₂ O ₂ ) as a base and europium (Eu) or copper (Cu) as an activator can be used. Alternatively, a phosphor containing barium / magnesium / aluminum composite oxide (Ba ₃ MgAl ₁₀ O ₁₇ ) as a base and europium (Eu) or manganese (Mn) as an activator can be used. A phosphor containing Ce and Tb as activators can be used with lanthanum phosphate (LaPO ₄ ) as a base material.

  The inorganic phosphor is in the form of particles, for example, having an average particle diameter of 0.3 to 10 μm, preferably 0.4 to 8 μm, more preferably 0.5 to 5 μm. By using particles having an average particle diameter in this range, aggregation is unlikely to occur, and when used in a coating layer, a uniform coating film can be obtained, and when used in a film, fine voids are formed and fracture occurs. Therefore, it is preferable that the film can be formed without using the film.

These inorganic phosphors are commercially available. For example, green light-emitting inorganic phosphor 2210 (ZenS made by Kasei Optronics Co., and Cu as an activator), red inorganic phosphor D1110 (manufactured by Nemoto Special Chemical Co., Ltd.) , Y ₂ O ₃ as a matrix, Eu as an activator), blue inorganic phosphor D1230 (manufactured by Nemoto Special Chemical Co., Ltd., SrS as a matrix, Eu as an activator), green inorganic phosphor KX732A ( Made by Kasei Optronics, barium / magnesium / aluminum composite oxide (Ba ₃ MgAl ₁₀ O ₁₇ ) as a base material, Eu and Mn as activators), green inorganic phosphor LP-G2 (manufactured by Nemoto Special Chemical Co., Ltd.) , lanthanum phosphate (LaPO ₄₎ as a matrix, Ce, Tb become as the activator) were available on the market using Door can be.

  Among organic phosphors, stilbene-based, distilbene-based, benzoxazole-based, styryl-oxazole-based, pyrene-oxazole-based, coumarin-based, imidazole-based, and benzimidazole are phosphors that satisfy the requirements for the excitation wavelength and emission wavelength described above. , Pyrazoline, aminocoumarin, distyryl-biphenyl, naphthalimide, and the like can be used. Among them, from the viewpoint of obtaining relatively high durability and brightness, Eastbright OB-1 (manufactured by Eastman: benzoxazole), Uvitex-OB (manufactured by Ciba Geigy: styryl / oxazole), Lummogen Green 850 ( BASF (Naphthalimide type) is preferable.

  The phosphor can be blended in the coating layer or in the light reflecting layer containing voids. In any case, the content of the phosphor based on the weight of the layer containing the phosphor is 4 to 40% by weight, preferably 5 to 35% by weight. If it is less than 4% by weight, high illuminance cannot be maintained. On the other hand, if the amount exceeds 40% by weight, it is difficult to disperse particles in the layer, a uniform coating layer cannot be obtained, and the dispersibility of the phosphor is poor, so that the stretchability during film formation may be poor. .

  When the phosphor is blended in the light reflecting layer containing voids, if inorganic phosphor particles are used as the phosphor, they also function as inorganic particles used to form voids in the thermoplastic resin. That is, since the interface between the inorganic phosphor particles and the thermoplastic resin is peeled off by stretching the thermoplastic resin film, a fine void can be formed.

[Ultraviolet absorber]
You may mix | blend a ultraviolet absorber with the thermoplastic resin film in this invention. Examples of the ultraviolet absorber include inorganic ultraviolet absorbers such as benzophenone, benzotriazole, triazine, cyanoacrylate, salicylic acid, benzoate, oxalic anilide, and sol-gel. Further, it is more effective to use a hindered amine light stabilizer in combination. An ultraviolet absorber may be mix | blended with a light reflection layer, and may be mix | blended with the coating layer containing fluorescent substance.

[Production method]
Hereinafter, an example of the method of manufacturing the thermoplastic resin film used as a reflective film of LED lighting of this invention is demonstrated. Here, on a laminated film comprising a light reflecting layer containing fine voids formed by stretching a layer of a thermoplastic aromatic polyester containing barium sulfate and a supporting layer of the thermoplastic aromatic polyester in contact with the light reflecting layer. A description will be given by taking as an example a configuration in which a phosphor-containing layer is provided by coating.

[Production of film containing fine voids]
The compounding of the barium sulfate particles into the polyester composition may be performed at the time of polymerization of the polyester or may be performed after the polymerization. When performing at the time of superposition | polymerization, you may mix | blend before transesterification reaction or esterification reaction completion, and may mix | blend before polycondensation reaction start. When it is performed after polymerization, it may be added to the polyester after polymerization and melt-kneaded. In this case, a master pellet containing barium sulfate particles at a relatively high concentration is produced, and a polyester composition containing barium sulfate particles at a desired content is prepared by blending this into a polyester pellet containing no barium sulfate particles. Can be obtained.

  It is preferable to filter the polyester composition by using a nonwoven fabric type filter having an average opening of 10 to 100 μm, preferably an average opening of 20 to 50 μm made of stainless steel fine wire having a wire diameter of 15 μm or less as a filter for film formation. . By performing this filtration, it is possible to obtain a film with few coarse foreign matters by suppressing aggregation of particles that generally tend to aggregate into coarse aggregate particles.

  An unstretched sheet is produced from the polyester composition melted from the die by a simultaneous multilayer extrusion method using a feed block. That is, the polyester composition melt constituting the light reflection layer and the polyester composition melt constituting the support layer are laminated to form the light reflection layer / support layer using a feed block, and developed on a die. And extruding. At this time, the polyester composition laminated by the feed block maintains the laminated form.

  The unstretched sheet extruded from the die is cooled and solidified with a casting drum to obtain an unstretched film. The coating liquid used for coating the coating layer is preferably applied to the unstretched film or to a longitudinally stretched film that has been subjected to subsequent longitudinal stretching.

  An unstretched film is heated by roll heating, infrared heating, or the like, and stretched in the longitudinal direction to obtain a longitudinally stretched film. This stretching is preferably performed by utilizing the difference in peripheral speed between two or more rolls. The stretching temperature is preferably a temperature equal to or higher than the glass transition point (Tg) of the polyester, and more preferably a temperature higher by Tg to 70 ° C. The draw ratio is preferably 2.2 to 4.0 times, more preferably 2.3 to both the longitudinal direction and the direction orthogonal to the longitudinal direction (hereinafter referred to as the transverse direction), although it depends on the required characteristics of the application. 3.9 times. If it is less than 2.2 times, the thickness unevenness of the film is deteriorated and a good film cannot be obtained, and if it exceeds 4.0 times, breakage tends to occur during film formation, which is not preferable.

  The longitudinally stretched film is subsequently subjected to lateral stretching, heat setting, and thermal relaxation to form a biaxially oriented film, which is performed while the film is running. The transverse stretching process starts from a temperature higher than the glass transition point (Tg) of the polyester. And it is performed while raising the temperature to (5 to 70) ° C. higher than Tg. Although the temperature rise in the transverse stretching process may be continuous or stepwise (sequential), the temperature is usually raised sequentially. For example, the transverse stretching zone of the tenter is divided into a plurality along the film running direction, and the temperature is raised by flowing a heating medium having a predetermined temperature for each zone. The transverse stretching ratio is preferably 2.5 to 4.5 times, more preferably 2.8 to 3.9 times, although it depends on the required characteristics of this application. If it is less than 2.5 times, the thickness unevenness of the film is deteriorated and a good film cannot be obtained, and if it exceeds 4.5 times, breakage tends to occur during film formation.

  The film after transverse stretching is heat-fixed with a constant width or a decrease in width of 10% or less from (Tm-20 ° C.) to (Tm-80 ° C.) while holding both ends to reduce the heat shrinkage rate. Good. When the heat setting temperature is higher than this, the flatness of the film is deteriorated, and the thickness unevenness is unfavorable. If it is lower than this, the heat shrinkage rate may increase, which is not preferable. In the process of returning the film temperature to room temperature after heat setting, both ends of the film being held can be cut off, the take-up speed in the film vertical direction can be adjusted, and the film can be relaxed in the vertical direction.

As a means for relaxing, the speed of the roll group on the tenter exit side is adjusted. As the rate of relaxation, the speed of the roll group is reduced with respect to the film line speed of the tenter, preferably 0.1 to 1.5%, more preferably 0.2 to 1.2%, particularly preferably 0.3. The film is relaxed by performing a speed reduction of ˜1.0% (this value is referred to as “relaxation rate”), and the longitudinal heat shrinkage rate is adjusted by controlling the relaxation rate. Further, the width of the film in the horizontal direction can be reduced in the process until both ends are cut off, so that a desired heat shrinkage rate can be obtained.
Here, the case of stretching by the sequential biaxial stretching method has been described in detail as an example, but the laminated film of the present invention may be stretched by either the sequential biaxial stretching method or the simultaneous biaxial stretching method.

[Coating of coating layer containing phosphor]
The coating layer containing the phosphor may be applied directly to the film containing fine voids. However, if the adhesiveness is insufficient, the surface containing the fine voids is subjected to corona discharge treatment. It is preferable to perform a subbing treatment or a coating on it. The undercoating treatment may be a method (inline coating method) provided in the white film manufacturing process, or may be applied separately after the film is manufactured. A material to be applied to the subbing treatment may be selected as appropriate, and as a suitable material, copolymerized polyester, polyurethane, acrylic, various coupling agents, and the like can be applied.

  The coating layer containing the phosphor can be applied by any method. For example, methods such as gravure, roll, spin, reverse, bar, screen, and dipping can be used. A known method can be used as a method for curing the coated film after coating. For example, a method using actinic rays such as thermosetting, ultraviolet rays, electron beams, and radiation, and a combination of these methods can be applied. The coating may be applied to a film that has not been stretched (in-line coating), or may be applied to a film after completion of crystal orientation (off-line coating).

Hereinafter, the present invention will be described in detail by way of examples. Each characteristic value was measured by the following method.
(1) Film thickness 10-point thickness was measured for the film sample with an electric micrometer (K-402B manufactured by Anritsu), and the average value was defined as the film thickness.

(2) Thickness of each layer A film sample was cut into a triangle, fixed in an embedded capsule, and then embedded in an epoxy resin. And after making the cross section parallel to the vertical direction into a thin film slice with a microtome (ULTRACUT-S), the embedded sample was observed and photographed using an optical microscope, and the thickness ratio of each layer was measured from the photograph. The thickness of each layer was calculated from the thickness.

(3) Reflectance An integrating sphere is attached to a spectrophotometer (Shimadzu Corporation UV-3101PC), and the reflectance when BaSO ₄ white plate is 100% is measured over 400 to 700 nm. From the obtained chart, the interval is 2 nm. The reflectance was read. In this measurement, measurement was performed from the side of the layer containing the phosphor.

(4) Stretchability It was observed whether the film could be stably formed when the stretch ratio was 2.8 times in the longitudinal direction and 3.3 times in the transverse direction. Evaluation was made according to the following criteria.
○: A film can be stably formed for 1 hour or more.
X: Cutting occurred before 1 hour passed, and stable film formation was not possible.

(5) Yellowing with time The color change before and after the irradiation time of 50 hours was observed by irradiation with a high-pressure mercury lamp ("Toscure 401" manufactured by Harrison Toshiba Lighting). The irradiance at this time was about 18 mW / cm ² . Irradiation to the film was measured by irradiating from the layer containing the phosphor.
The initial film hue (L ₁ ^* , a ₁ ^* , b ₁ ^* ) and the film hue after irradiation (L ₂ ^* , a ₂ ^* , b ₂ ^* ) were compared with a color difference meter (Nippon Denshoku Industries SZS- (Σ90 COLOR MEASURING SYSTEM), a hue change dE * represented by the following formula was calculated, and evaluated according to the following criteria.
dE ^* = {(L ₁ ^* −L ₂ ^* ) ² + (a ₁ ^* −a ₂ ^* ) ² + (b ₁ ^* −b ₂ ^* ) ² } ^1/2
A: dE ^* ≦ 5
○: 5 <dE ^* ≦ 10
Δ: 10 <dE ^* ≦ 15
×: 15 <dE ^*

(6) Relative illuminance LED lighting AKLD1000WN manufactured by Mitsubishi Electric Corporation is turned on in a room adjusted to 25 ° C. and 50% RH, and the illuminance directly in front of the light source at a position 50 cm away from the light source is measured by the illuminometer LX2 manufactured by Sanwa It was measured. The illuminance at this time was 75 lx. This is hereinafter referred to as “original illuminance”. Next, the main body, the frame (aluminum plate + white coating), and the plastic reflector were all replaced with the film sample, and the illuminance was measured by the same measurement.
Relative illuminance = 100 x (illuminance at film sample) / (original illuminance)

(7) Chromaticity difference The chromaticity (x, y) was measured using a luminance meter (Topcon BM-7) in the same manner as the relative illuminance. Using the measured chromaticity, the difference from the reference color (chromaticity difference) was calculated using the following formula.
Δx = reference coordinate (x = 0.300) −measurement coordinate (x)
Δy = reference coordinate (y = 0.310) −measurement coordinate (y)
Δxy = (Δx ² + Δy ² ) ^1/2

(8) Void volume ratio After isolating only the film layer containing fine voids, the density was determined using an anton pearl vibration digital density meter DMA4500, and then the film of the reflective layer A was melted to determine the density. The following formula was used.
Void volume ratio (%) = 100-100 × (density before melting) / (density after melting)

[ Reference Example 1]
132 parts by weight of dimethyl terephthalate, 18 parts by weight of dimethyl isophthalate (12 mol% based on the acid component of the polyester), 96 parts by weight of ethylene glycol, 3.0 parts by weight of diethylene glycol, 0.05 part by weight of manganese acetate, 0 parts of lithium acetate .012 parts by weight were charged into a rectifying column and a flask equipped with a distillation condenser, and heated to 150 to 235 ° C. with stirring to distill methanol to conduct a transesterification reaction. After the methanol was distilled off, 0.03 part by weight of trimethyl phosphate and 0.04 part by weight of germanium dioxide were added, and the reaction product was transferred to the reactor. Subsequently, while stirring, the pressure in the reactor was gradually reduced to 0.5 mmHg and the temperature was raised to 290 ° C. to carry out a polycondensation reaction. The obtained copolymer polyester had a diethylene glycol component amount of 2.5% by weight, a germanium element amount of 50 ppm, and a lithium element amount of 5 ppm. A master batch was prepared by using this polymer for layer A and adding 48% by weight of barium sulfate having an average particle size of 1.0 μm as inorganic particles.

  Further, the masterbatch containing 48% by weight of barium sulfate described above and the polymer before addition of barium sulfate were diluted to 5% by weight of barium sulfate and used for layer B. Each was supplied to two extruders heated to 275 ° C., and layer A polymer (barium sulfate concentration 48 wt%) and layer B polymer (barium sulfate concentration 5 wt%) were divided into layers A and B as A / B. The two-layer feed block device was used to join, and the sheet was formed into a sheet from a die while maintaining the laminated state. Further, an unstretched film obtained by cooling and solidifying this sheet with a cooling drum having a surface temperature of 25 ° C. was heated at 83 ° C., stretched 2.8 times in the longitudinal direction (longitudinal direction), and cooled with a roll group at 25 ° C. Subsequently, while holding both ends of the longitudinally stretched film with clips, the film was stretched 3.3 times in a direction (lateral direction) perpendicular to the longitudinal direction in an atmosphere guided to a tenter and heated to 115 ° C. Thereafter, heat setting was performed at 195 ° C. in a tenter, and the mixture was cooled to room temperature to obtain a biaxially stretched film. This biaxially stretched film contains fine voids.

On the layer A side of the obtained biaxially stretched film, “Utable” S2740 (manufactured by Nippon Shokubai) as a binder, “Coronate HL” (manufactured by Nippon Polyurethane) as an isocyanate-based crosslinking agent, and a fluorescent material in a butyl acetate solution A coating material to which a fluorescent material “2210” (manufactured by Mitsubishi Chemical Corporation) was added so that the solid content ratio was 4% by weight was applied so that the thickness after drying was 5 μm. In addition, the solid content weight ratio after drying is binder / isocyanate crosslinking agent / phosphor = 85/11/4, and the coating liquid solid content concentration is 45% by weight. The drying conditions were hot air drying at 120 ° C. for 2 minutes.
The relative illuminance measured for the resulting film was 108%.

[ Reference Examples 2 to 8]
Reference Example 1 except that the solid content weight ratio of the binder and the isocyanate cross-linking agent was changed as shown in Table 1 while changing the type and content of the phosphor in the coating layer while maintaining the ratio (85/11) of Reference Example 1. Similarly, a coated film was obtained. The evaluation results of the obtained films are as shown in Table 1, and it was confirmed that the illuminance was improved.

[Examples 9 and 10]
As shown in Table 1, the phosphor was added from the feed port of the extruder of layer A so that the content of barium sulfate particles in layer A was 48% by weight and the content of phosphor was 10% by weight. A two-layer film consisting of A / layer B was prepared. The evaluation results of the obtained films are as shown in Table 1, and it was confirmed that the illuminance was improved.

[Example 11]
As shown in Table 1, the phosphor is added to the extruder feed port of the layer A, to create a two-layer film comprising a layer A / layer B, and the same coating agent as in Reference Example 1 on the surface of the layer A reference Application was the same as in Example 1.
The evaluation results of the obtained film are as shown in Table 1.

[Example 12]
As shown in Table 1, an organic phosphor was added from the feed port of the extruder of layer A to form a two-layer film consisting of layer A / layer B. The evaluation results of the obtained film are as shown in the table.

[ Reference Example 9 ]
As shown in Table 1 to prepare a coating by following the surface layer in an organic phosphor layer A of the two-layer film of the layer A / the layer B obtained in Reference Example 1 to Reference Example 1 film. The evaluation results of the obtained film are as shown in the table.

[Comparative Examples 1 to 10]
A film was prepared in the same manner as in Reference Example 1 except that the types and contents of the phosphors in the coating layer and layer A were adjusted as shown in Table 1. Comparative Example 10 was poor in stretchability and could not be sampled. All the films from which the samples could be collected were inferior in illuminance.

  The thermoplastic resin film used as a reflection film for LED lighting of the present invention can be particularly suitably used as a lighting reflection film for indoor or outdoor lighting in buildings.

Claims (7)

A thermoplastic resin film containing fine voids and phosphors,
The thermoplastic resin film is composed of one or more layers, comprising a light reflecting layer composed of the composition of a thermoplastic resin containing fine voids, the light reflective layer based on the weight of the light-reflecting layer Containing 4-40% by weight of phosphor,
The void volume ratio of the light reflecting layer is 35 to 75%,
A thermoplastic resin film characterized by being used as a reflection film for illumination using an LED as a light source. Thermoplastic resin film, the light-reflecting layer, and a phosphor-containing coating layer formed by coating on top of the light reflecting layer, a thermoplastic resin film of claim 1, wherein. The thermoplastic resin film according to claim 1 or 2 , wherein the light reflecting layer contains a thermoplastic resin and a substance incompatible with the resin . The thermoplastic resin film according to claim 3 , wherein the incompatible substance is inorganic particles. The thermoplastic resin film according to claim 3, wherein the incompatible substance is an incompatible resin. The thermoplastic resin film according to any one of claims 1 to 5, wherein the phosphor is an inorganic phosphor. The thermoplastic resin film according to claim 1, wherein the illumination using an LED as a light source is illumination for indoor or outdoor illumination of a building.