JP5564808B2 - White reflective film - Google Patents

Description

  The present invention relates to a white reflective film that improves the luminance of a backlight for a liquid crystal display and suppresses a change in chromaticity. More specifically, an edge light type backlight lamp reflector for liquid crystal displays, an edge light type and / or direct type type backlight for a liquid crystal display, a white reflective film, a solar cell module sealing film, The present invention relates to a white reflective film for a back sheet.

  In a liquid crystal display, a backlight that illuminates a liquid crystal cell is used. Depending on the type of liquid crystal display, the LCD monitor employs an edge light type backlight, and the liquid crystal television employs a direct type backlight. As a reflective film used for these backlights, a porous white film formed of bubbles is generally used (Patent Document 1). Furthermore, in order to prevent yellow discoloration of the film due to ultraviolet rays emitted from a lamp such as a cold cathode tube, a white film in which an ultraviolet absorbing layer is laminated has also been proposed (Patent Documents 2 and 3).

  In a rapidly growing reflective film for liquid crystal televisions, cost reduction is strongly demanded, while improvement of the reflective properties of the reflective film is also demanded at the same time. This is because if the luminance as a backlight is improved by improving the reflection characteristics of the reflective film, the expensive sheet used on the upper part of the light source can be reduced. Therefore, various methods for improving various reflection characteristics in these reflective films have been disclosed. For example, a white film containing a very small amount of various fluorescent brighteners for the purpose of adjusting the color in the ultraviolet absorbing layer laminated on the white film has been proposed (Patent Documents 3, 4, 5, 6). . In addition, a method of controlling light diffusibility by selecting a difference in refractive index between spherical particles and a binder and improving front luminance by a light diffusion sheet is disclosed (Patent Document 7).

JP-A-8-262208 JP 2001-166295 A JP 2002-90515 A JP 2006-48039 A JP 2005-173546 A Japanese Patent Laid-Open No. 2006-343864 JP 2001-324608 A

  However, although the reflection characteristics of the reflective film often depend on the void structure inside the white film, there is a limit to improving the reflection characteristics by devising the void structure as in Patent Document 1. Further, in the method in which an ultraviolet absorbing layer is provided as in Patent Documents 2 and 3, or in a method in which a small amount of fluorescent brightener is contained in the ultraviolet absorbing layer as in Patent Documents 3 to 6, the absorbed ultraviolet energy is converted into heat. It can only be converted into a small amount of light that either converts or contributes to the color adjustment of the reflective film. Furthermore, in the case of Patent Document 7, since the effect on ultraviolet rays emitted from a lamp such as a cold cathode tube is small, the use efficiency of light energy as a substantial backlight does not increase with these methods, and eventually Not only does it not lead to a dramatic improvement in brightness, but it also causes yellowing depending on the amount of fluorescent whitening agent added together, so the chromaticity of the backlight light changes significantly, and consequently the color reproducibility of the screen decreases. The actual situation is that the image quality is degraded.

  In view of the background of such prior art, the present invention intends to provide a white reflective film capable of improving the luminance of a liquid crystal backlight and suppressing chromaticity change.

In order to solve this problem, the present invention employs the following configuration. That is, in the white reflective film of the present invention, at least one resin layer containing a compound corresponding to the following (i) and a compound corresponding to the following (ii) is laminated on at least one surface of the white film,
The content of the compound corresponding to (i) is 0.05% by mass or more and 5% by mass or less with respect to the entire resin layer,
The content of the compound corresponding to (ii) is 4 % by mass or more and 13 % by mass or less with respect to the entire resin layer.
(I) A compound having the following structure (1) and / or (2) in the molecule and not having the following structures (3), (4) and (5) in the molecule.
(Ii) A compound having the following structures (2) and (3) in the same molecule .

(R ₁ = aryl group having 6 to 12 carbon atoms, hydrogen. R ₂ = carbon having 1 to 7 elements other than carbon and hydrogen, and heterocycle having 1 to 7 elements other than carbon and hydrogen. A substituted heterocyclic ring to which an aryl group of 6 to 12 is bonded, an amino group, a substituted amino group to which an ester group having 2 to 5 carbon atoms is bonded, and a substituent having any element of oxygen, nitrogen, halogen, and sulfur A substituted amino group bonded to a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, and the heterocyclic ring bonded thereto, hydrogen R ₃ = a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, structure ( 3) Carbon and hydrogen to which R ₆ is bonded R ₄ = C 1-6 linear / branched / cyclic alkyl group, hydrogen R ₅ and R ₇ = sulfonic acid group, hydrogen R ₆ = amino Group, oxygen, nitrogen, halogen, or sulfur Carbon substituents wherein the carbon and substituted amino groups in which the heterocycle is bonded to the heterocyclic ring is bonded with an element number 1-7 other than hydrogen, the R ₃ structure (2) are attached, hydrogen.)
In a preferred embodiment of the white reflective film of the present invention, the compound corresponding to the above (ii) has the structures of the above structures (2) and (3) in the same molecule separately from the compound corresponding to the above (i). It is characterized by being. Further, the backlight lamp reflector and the direct type backlight of the present invention are configured such that the white reflective film of the present invention is provided with the surface on which the resin layer is laminated facing the light source side. It is a feature. Further, the edge light type backlight of the present invention is characterized in that the white reflective film of the present invention is provided with the surface on which the resin layer is laminated facing the light guide plate side. It is. Moreover, the sealing film for solar cells of the present invention uses the white reflective film of the present invention for sealing a solar cell module.

  According to the present invention, by providing a specific resin layer on at least one side of a white film, it is possible to provide a white reflective film that improves the luminance of the backlight when used in a backlight and suppresses chromaticity changes. .

It is an example of the cross-sectional schematic diagram of the white reflective film of this invention. It is an example of the cross-sectional schematic diagram of the white reflective film of this invention which contained particle | grains in the resin layer.

  The white reflective film of the present invention is one in which at least one resin layer containing a compound corresponding to the above (i) and a compound corresponding to the above (ii) is provided on at least one surface of the white film. When such a resin layer contains a compound corresponding to the above (i) and a compound corresponding to the above (ii), it is not clear why the change in chromaticity can be suppressed while improving the luminance of the backlight. It is estimated that this is the reason.

  That is, for example, cold cathode tubes used for liquid crystal backlights generally have emission peaks in the ultraviolet region near 310 to 315 nm, the ultraviolet region near 360 to 370 nm, and the near ultraviolet region near 400 to 410 nm, and longer wavelengths than that. Since there are a plurality of emission peaks in the visible light region on the side, white light is reproduced by mixing each light. Here, by selecting a compound corresponding to the above (ii) as an additive to the resin layer, among the light emitted from the cold-cathode tube, the light in the ultraviolet region that hardly contributes to the luminance, the conventional ultraviolet absorber In the near-ultraviolet region light that cannot be absorbed in the above, and in the visible light region higher than that, the light is appropriately absorbed, and the wavelength is different from the region having the effect of adjusting the color, that is, the wavelength in the visible light region contributing to the luminance. It is estimated that the brightness is improved by selectively converting and releasing.

  On the other hand, the compound corresponding to the above (i) converts and emits light emitted from the cold cathode tube in the same manner as the compound corresponding to the above (ii), but the emission wavelength region corresponds to the above (ii). Unlike the compound to be added, the effect of improving the brightness is added by being contained in the resin layer together with the compound corresponding to the above (ii) that exists in a shorter wavelength region, and corresponds to the above (ii) It is estimated that the compound compensates for the light in the region that was lacking, and as a result, the change in chromaticity is suppressed. Furthermore, this effect is not limited to cold cathode fluorescent lamps, and the above-described effects can be exhibited if the light source or lamp has light emission in the near ultraviolet region or lower.

The white reflective film of the present invention has at least one resin layer containing, on at least one side of the white film, a compound corresponding to the following (i) and at least one kind of compounds corresponding to the following (ii): It is a laminated one.
(I) A compound having the structure (1) and / or (2) in the molecule and not having the structures (3), (4) and (5) in the molecule.
(Ii) A compound having in its molecule at least one structure selected from the group consisting of the structures (3), (4) and (5).
(R ₁ = aryl group having 6 to 12 carbon atoms, hydrogen, R ₂ = carbon having 1 to 7 elements other than carbon and hydrogen, and heterocycle having 1 to 7 elements other than carbon and hydrogen. A substituted heterocyclic ring to which an aryl group of 6 to 12 is bonded, an amino group, a substituted amino group to which an ester group having 2 to 5 carbon atoms is bonded, and a substituent having any element of oxygen, nitrogen, halogen, and sulfur A substituted amino group bonded to a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, and the heterocyclic ring bonded thereto, hydrogen R ₃ = a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, structure ( 3) Carbon and hydrogen to which R ₆ is bonded R ₄ = C 1-6 linear / branched / cyclic alkyl group, hydrogen R ₅ and R ₇ = sulfonic acid group, hydrogen R ₆ = amino Group, oxygen, nitrogen, halogen, or sulfur Carbon substituents wherein the carbon and substituted amino groups in which the heterocycle is bonded to the heterocyclic ring is bonded with an element number 1-7 other than hydrogen, the R ₃ structure (2) are attached, hydrogen.)
If such a resin layer is not provided, or if it does not contain any one of the compounds corresponding to (i) and (ii), even if the white reflective film is incorporated in the backlight, the brightness enhancement effect is not obtained, The chromaticity change is not suppressed, and a large chromaticity change is caused. The resin layer defined in the white reflective film of the present invention is a layer composed of a polymer compound containing an organic component and / or an inorganic component, and the form of the resin layer is a thin film on the white film, Although the composite layer etc. by the bonding of films are mentioned, it is not specifically limited to these.

  The resin layer according to the present invention contains both the compound corresponding to (i) and the compound corresponding to (ii), and the compound corresponding to (i) has the structure (1 ) And / or (2) and the structure (3), (4) and (5) must not be present in the molecule, and the compound corresponding to the above (ii) is The molecule must have at least one structure selected from the group consisting of the structures (3), (4) and (5) in the molecule. When one compound does not have any of the structures (1) and (2), the chromaticity change is not suppressed when the resin layer is provided, and a large chromaticity change is caused. In addition, when the other compound does not have any of the structures (3) to (5), the brightness enhancement effect cannot be obtained.

  Here, the compounds corresponding to the above (i) and (ii) may each contain a plurality of types, for example, a compound having the structure (1) (a compound corresponding to the above (i)) and a structure (3) (4) A mixture containing both (compounds corresponding to the above (ii)) may be included. However, in the same molecule, a compound having “the structure (1) and / or (2)” and “at least one selected from the group consisting of the structures (3), (4) and (5)” (for example, The compounds having the structures (1) and (3) and the compounds having the structures (2) and (3) do not correspond to the above (i) but become compounds corresponding to the above (ii). In the case where the same molecule has the structure “the structure (1) and / or (2)” and “at least one selected from the group consisting of the structures (3), (4) and (5)” This is because the luminance improvement effect of the structure (3), (4) or (5) is more easily expressed than the effect of suppressing the chromaticity change by the structure (1) or (2) described above. In the present invention, the same molecule has “the structure (1) and / or (2)” and “at least one selected from the group consisting of the structures (3), (4) and (5)”. When a compound (compound corresponding to the above (ii)) is contained, it is necessary to separately contain a compound corresponding to the above (i).

  The structures (1) to (5) may be included in any bonding mode, for example, various substituents, backbone structures, and covalent bonds and ions with components forming the resin layer such as a binder resin. It may be contained by a bond, a coordination bond, or the like. In that sense, when they are contained in the resin layer, they may be contained alone, but they may be selected according to the application and characteristics, and are not particularly limited.

R _n (n = 1 to 7) shown in the structures (1) to (5) of the compound according to the present invention is bonded to various substituents or molecules contained in a resin layer such as a backbone structure or a binder resin. Means. Basically, it only needs to have the structure shown by the structures (1) to (5) for exhibiting the brightness enhancement effect and the suppression effect of the chromaticity change, and the productivity is good within the range not hindering the use and the required characteristics. There are also two or more different substituents and bonding states that can be used by arbitrarily selecting substituents or bonding states having good compatibility such as compatibility with the solvent used and resins and additives used together. May be used, or an unsubstituted simple substance may be used, and is not particularly limited. Examples of such substituents in R ₁ include phenyl group, tolyl group, xylyl group, naphthyl group, is an aryl group or hydrogen having 6 to 12 carbon atoms such as a biphenyl group, a heterocyclic ring including the element number 1 to 7 other than carbon and hydrogen, such as R ₂ in the triazine thiophene lactone-oxazole-imidazole, before An ester group having 2 to 5 carbon atoms, such as a substituted heterocyclic ring in which an aryl group having 6 to 12 carbon atoms is bonded to a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, and the like, is bonded. A substituted amino group, a substituent having any element of oxygen, nitrogen, halogen, and sulfur is bonded to a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, and the substituted amino group to which the heterocyclic ring is bonded In R ₃ , carbons such as triazine, thiophene lactone, oxazole, imidazole and the like and heterocycles having 1 to 7 elements other than hydrogen, carbons to which R _{6 of the} structure (3) is bonded, and hydrogen In R ₄ , methyl group, ethyl group, iso-propyl group, iso-butyl group, sec-butyl, tert-butyl group, cyclopropyl group, cyclobutyl group, cyclo Examples thereof include straight-chain / branched / cyclic alkyl groups having 1 to 6 carbon atoms such as pentyl group and cyclohexyl group, and hydrogen, and R ₅ and R ₇ include sulfonic acid groups such as sodium sulfonate group and hydrogen, and R ₆ In the amino group, a substituent having any element of oxygen, nitrogen, halogen and sulfur is bonded to the heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, and the substituted amino group to which the heterocyclic ring is bonded, Examples thereof include carbon and hydrogen to which R _{3 of the} structure (2) is bonded, and these can be appropriately selected and used.

  The compound corresponding to the above (ii) according to the present invention further preferably has both the structures (2) and (3) in the same molecule separately from the compound corresponding to the above (i). . When both structures (2) and (3) are provided, a higher luminance improvement effect can be obtained as compared with the case where only one kind selected from structures (3) to (5) is provided. The compounds having the structures (2) and (3) in the same molecule here do not correspond to the above (i) as described above, and in the resin layer of the present invention, the structures (2) and (3 And a compound having both structures. The reason why the brightness enhancement effect is further obtained by having such both structures is not clear, but it is possible to more efficiently absorb ultraviolet rays emitted from a lamp such as a cold cathode tube, and to absorb in a wide wavelength region, It is presumed that light emission occurs on the longer wavelength side and light in a wide wavelength range can be emitted, so that the utilization efficiency of substantial light energy is further improved. However, when a compound having both structures (2) and (3) is selected, yellowing occurs depending on the type of additive and binder resin mixed together in the resin layer, and particularly the content in the resin layer. May cause.

  On the other hand, in the case of having only one type selected from the structures (3) to (5), the luminance improvement effect is lower than in the case of having both the structures (2) and (3), but the chromaticity change tends to be less. Therefore, it is possible to use either by selecting one of them depending on the application or important characteristics, changing the content rate, or mixing one having both structures with one having only one type. it can.

  Specific examples of the compound having in the molecule thereof at least one structure selected from the group consisting of structures (1) to (5) include, for example, Eastobrite OB-1 (manufactured by Eastman Chemical Company), Kayight Series (manufactured by Nippon Kayaku Co., Ltd.), Kayphor series (manufactured by Nippon Kayaku Co., Ltd.), Mikawhite series (manufactured by Nippon Kayaku Co., Ltd.), UVITEX OB (manufactured by Ciba Specialty Chemicals Co., Ltd.), Hostalux Series (manufactured by Clariant Japan Co., Ltd.), Shigenox series (manufactured by Hakkor Chemical Co., Ltd.), Hakkol series (manufactured by Hakkor Chemical Co., Ltd.), Lumogen (registered trademark) F Violet 570 (manufactured by BASF), Lumogen (registered) Mark) F Blue650 (manufactured by BASF), may be used Lumogen (TM) OB 433 (manufactured by BASF), etc., but it is not particularly limited thereto.

  Various particles can be further added to the resin layer according to the present invention together with the compounds corresponding to the above (i) and (2), and nonporous spherical particles and / or porous particles can be particularly preferably used.

  When non-porous spherical particles are contained, a significant improvement in luminance can be obtained, and the amount of compound having a specific structure in the molecule necessary to obtain the same luminance as compared with the case where no non-spherical particles are contained. As a result, there may be a case where a great advantage is obtained in terms of cost and productivity. The term “nonporous” as used herein refers to a state having no pores, which will be described later, and those having a plurality of pores on the particle surface are porous. The term “spherical” does not necessarily mean only a true sphere, but a particle whose cross-sectional shape is surrounded by a curved surface such as a circle, an ellipse, a substantially circle, or a substantially ellipse.

  On the other hand, when containing porous particles, it becomes easier to suppress chromaticity change, can increase the content in the resin layer of the compound corresponding to the above (ii) contributing to the brightness improvement effect, and thus Furthermore, there are cases where a brightness improvement effect can be obtained. Here, the porous particle is a particle having a plurality of pores on the particle surface, and the pore is a portion recessed in a concave shape toward the inside of the particle, for example, a hollow shape. Or a shape that is recessed toward the center or center of the particle, such as a needle or a curve, or a shape that penetrates the particle, etc., and its size and volume may vary widely, particularly limited to these is not. Furthermore, the shape of the porous particles according to the present invention is not uniquely limited, for example, a flat shape such as a star shape, a leaf shape or a disk shape, a rhombus shape, a rectangular shape, a needle shape, a scalloped sugar shape, an indefinite shape. However, it is more preferable that the shape is spherical. When the shape of the porous particles is spherical, a brightness improvement effect can be further obtained. As compared with the non-spherical shape, the amount of the compound required to obtain the same luminance can be reduced, which is more preferable from the viewpoint of cost and productivity. Here, “spherical” does not necessarily mean only a true sphere, but a particle whose cross-sectional shape is surrounded by a curved surface such as a circle, an ellipse, a substantially circle, or a substantially ellipse.

  By including non-porous spherical particles and / or porous particles together with the compounds corresponding to the above (i) and (ii) in such a resin layer, the reason why the luminance of the backlight is greatly improved and the chromaticity change are described. The reason why it becomes easier to suppress is not clear, but it is presumed that the reason is as follows. First, nonporous spherical particles will be described. As described above, for example, cold cathode tubes used for liquid crystal backlights generally have emission peaks in the ultraviolet region near 310 to 315 nm, the ultraviolet region near 360 to 370 nm, and the near ultraviolet region near 400 to 410 nm, respectively. Since there are a plurality of emission peaks in the visible light region on the long wavelength side, white light is reproduced by mixing each light. By making the particles contained here non-porous, it is possible to prevent the binder resin forming the resin layer from entering the particles. Therefore, together with the light in the visible light region emitted from the cold cathode tube, the light in the visible light region converted and emitted by the compound having the specific structure in the molecule is reflected and diffused repeatedly at the interface between the binder resin and the particles. By reducing the amount of light that does not propagate to the front, the loss of light can be reduced to the limit. In addition, by making the contained non-porous particles spherical, light in the visible light region that has been emitted from the cold cathode tube, reflected by the white film surface and transmitted through the resin layer, and the specific structure in the molecule It is presumed that the light in the visible light region emitted from the compound having the light is condensed without losing the light due to the lens effect at the spherical portion of the particles, and contributes to the improvement of the luminance in the front direction of the backlight.

  On the other hand, in the case of porous particles, an interface is formed when the binder resin that forms the resin layer enters into the particles, contrary to the case of nonporous, and a compound having the specific structure in the molecule is formed. The converted and emitted light in the visible light region enters the porous particles when passing through the resin layer, and the chromaticity change is suppressed by repeating multiple reflection and scattering at the interface in the pores. It is estimated that there is not. Further, when the shape of the porous particles is spherical, a spherical interface is formed between the porous particles and the resin in the resin layer, or the atmosphere in contact with the resin layer, that is, air, and light emitted from the compound and It is estimated that light from a lamp such as a cold-cathode tube produces a lens-like effect by refracting and changing the angle at each formed spherical interface, which in turn increases the amount of light on the front. Yes. When the non-spherical shape has a spherical change in the frontal direction of the light in the visible light region that contributes to the luminance of the light emitted from the compound by the lens effect and the light emitted from a lamp such as a cold cathode tube Estimated to decrease compared.

  Here, the “pores” and “shape” of the particles are obtained as follows. The sample is cut in a direction perpendicular to the film plane at a knife inclination angle of 3 ° using a rotary microtome manufactured by Nippon Microtome Laboratories. Using the scanning electron microscope ABT-32 manufactured by Topcon Corporation, the obtained film cross-section is, for example, at an observation magnification of 2500 to 10000 times, so that one particle is projected over the entire visual field region. The contrast is appropriately adjusted and observed, and the presence or absence of pores and the shape of the particles are judged. If the particles cannot be cut, immerse the resin layer in an organic solvent, peel off and collect the resin layer, and then press and slide on the slide glass to drop the particles from the resin layer and collect a sufficient amount of particles. . Subsequently, the obtained particles are used, for example, at an observation magnification of 2500 to 10,000 times, and an image so that one particle is projected over the entire visual field region using a scanning electron microscope ABT-32 manufactured by Topcon Corporation. The contrast is appropriately adjusted and observed, and the presence of pores and the shape of the particles are judged. Note that the presence / absence of pores is determined based on whether or not spots or spots are present in the particles in the observed image. No pores. In addition, as a material of particle | grains, any of an inorganic substance, an inorganic compound, an organic compound, and those composites may be sufficient, and it is not limited uniquely. As such organic particles, a resin mainly composed of a crosslinked polymer component having a high melting point is preferable. For example, polyester resin, polyamide resin particles such as benzoguanamine and nylon, polyurethane resin, acrylic resin, methacrylic resin, polyethylene resin, polypropylene Examples thereof include resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, fluorine resin, and silicone resin particles. These resins may be used alone, or the refractive index can be easily changed by adjusting the copolymerization ratio or mixing ratio of two or more kinds of copolymers or mixtures. Easy to adjust the refractive index difference. Examples of the inorganic particles include calcium carbonate, magnesium carbonate, zinc carbonate, titanium oxide, zinc oxide, cerium oxide, magnesium oxide, barium sulfate, zinc sulfide, calcium phosphate, silicon oxide (silica), aluminum hydroxide, aluminum oxide, Alumina, mica, mica titanium, talc, clay, kaolin, lithium fluoride, calcium fluoride, and the like can be used.

  The particles that may be contained in the resin layer according to the present invention are improved in luminance by appropriately changing the absolute value of the refractive index difference between the binder resin forming the resin layer and the particles (hereinafter referred to as the refractive index difference). The effect or suppression of chromaticity change can be controlled. If you want to get more brightness improvement effect, while the light in the visible light region that contributes to the brightness of the light emitted from the lamp such as a cold cathode tube is reflected by the white film surface and transmitted through the resin layer, Excessive reflection or diffusion occurs at the interface between the particles and the binder resin, reducing the amount of light reaching the resin layer surface.In other words, the loss of internal diffused light increases and the reflectivity decreases without improving. In order to prevent this, the difference in the refractive index between the binder resin and the particles should be as small as possible. Preferably, the difference in the refractive index between the binder resin and the particles forming the resin layer is 0.30 or less, and more preferably 0.10. Hereinafter, it is particularly preferably 0.05 or less. On the other hand, when it is desired to further suppress the change in chromaticity, in the pores generated when the light converted / released from the compounds corresponding to the above (i) and (ii) is incident on the porous particles when passing through the resin layer In addition, the effect of suppressing chromaticity change can be further increased by increasing the amount and number of multiple reflections and scattering at the interface between the particles and the binder resin, so the difference in the refractive index between the binder resin and the particles should be as large as possible. The refractive index difference between the binder resin forming the resin layer and the particles is preferably larger than 0.03, and more preferably 0.10 or more. In other words, since it depends on the type of the binder resin that forms the resin layer, it cannot be uniquely limited, and the refractive index difference is appropriately determined in consideration of the application, purpose, performance balance of brightness improvement effect and chromaticity change suppression effect, etc. What is necessary is just to select from the said range.

  The particles that may be contained in the resin layer according to the present invention are not particularly limited because of the thickness of the resin layer and the content of the compound corresponding to the above (i) and (ii) in the present invention, but the average volume particle diameter Is preferably 0.05 μm or more, more preferably 1 μm or more, and still more preferably 3 μm or more. That is, a convex structure may be formed on the outermost surface of the resin layer using particles having an average volume particle diameter larger than the thickness of the resin layer, and particles having an average volume particle diameter smaller than the thickness of the resin layer are used. Then, the surface of the resin layer may be as smooth as possible. When the average volume particle diameter is smaller than 0.05 μm, the backlight luminance improvement effect may not be obtained. Moreover, although an upper limit is not specifically limited, Since it may be inferior to workability when it exceeds 100 micrometers, 100 micrometers or less are preferable. The particle size distribution may be narrow with respect to the average volume particle size, that is, the particle size distribution may be uniform and uniform, or the particle size distribution may be wide, that is, the particle size may vary in various sizes from the average volume particle size. There may be.

  The content of the particles that may be contained in the resin layer according to the present invention is unambiguous because it also depends on the content of the compounds corresponding to the above (i) and (ii), the particle type, processability, etc. Is not particularly limited as long as the effect of improving luminance and the effect of suppressing chromaticity change can be obtained, but the entire resin layer containing the compound and particles corresponding to the above (i) and (ii) It is preferable that it is 3 mass% or more with respect to it, More preferably, it is 5 mass% or more, More preferably, it is 10 mass% or more, Most preferably, it is 15 mass% or more. When the amount is less than 3% by mass, the backlight luminance improving effect may not be added, or the chromaticity change suppressing effect may not be added. Moreover, although an upper limit is not specifically limited, If it exceeds 300 mass parts with respect to 100 mass parts of components other than the particle | grains in a resin layer, ie, 75 mass% of the whole resin layer, a light-resistant fall or drop-off | omission of a particle will be carried out. Since it may be inferior or inferior in productivity, 300 parts by mass, that is, 75% by mass or less of the entire resin layer is preferable with respect to 100 parts by mass of components other than particles in the resin layer.

  Various additives can be added to the particles in the present invention as long as the effects of the present invention are not impaired. Additives include, for example, UV absorbers, light stabilizers, crosslinking agents, flame retardants, flame retardant aids, heat stabilizers, oxidation stabilizers, organic lubricants, antistatic agents, nucleating agents, dyes, filling An agent, a dispersant, a coupling agent, and the like can be used.

  In the compounds and various particles corresponding to the above (i) and (ii) according to the present invention, from the viewpoint of improving dispersibility in the resin layer, maintaining stability, productivity, etc., the range does not impair the effects of the invention. Surface treatment may be performed.

  The compounds corresponding to the above (i) and (ii) according to the present invention preferably have a maximum absorption wavelength between wavelengths of 300 to 450 nm. In addition, the maximum absorption wavelength here is a wavelength at the maximum value of the absorption spectrum obtained by ultraviolet-visible spectrophotometry (UV-Vis) of a compound dissolved in a soluble solvent, and there are a plurality of maximum values. In some cases, any maximum absorption wavelength may exist between wavelengths of 300 to 450 nm. When the maximum absorption wavelength exists between wavelengths of 300 to 450 nm, even if the wavelength of light below the near ultraviolet region emitted from a lamp such as a cold cathode tube does not necessarily match the maximum absorption wavelength, the wavelength around the maximum absorption wavelength Since it has absorption in the region, it can be sufficiently converted into light in the visible light region. When the maximum absorption wavelength is on the shorter wavelength side than 300 nm, short wavelength light in the near ultraviolet region or less emitted from a lamp such as a cold cathode tube cannot be absorbed. Further, when the maximum absorption wavelength is on the longer wavelength side than 450 nm, not only the short-wavelength light below the near ultraviolet region emitted from the lamp such as a cold cathode tube can be absorbed, but also the lamp of the cold cathode tube or the like. Even light in the visible light region is absorbed, and conversely, there is a risk of causing a decrease in luminance and a significant change in chromaticity of backlight light.

  The compounds corresponding to (i) and (ii) according to the present invention preferably emit light between wavelengths of 350 to 600 nm. The light emission referred to here may be either fluorescence or phosphorescence, and is light generated when the absorbed light energy is emitted, and means that the entire emission spectrum exists between wavelengths of 350 to 600 nm. When light emission exists between wavelengths of 350 to 600 nm, the sensitivity of the perception is relatively high in the wavelength range of light that can be perceived by the general human eye, and the chromaticity change of the backlight light is not so large. As a result, the brightness of the backlight is improved, the chromaticity change of the screen is small, and a bright display can be achieved. This is because the lower limit of the emission wavelength is in the region of 350 nm or more, and it is recognized that the brightness is not changed by light emission in a wavelength region shorter than 350 nm, which is generally less sensitive to human eyes and difficult to perceive. In addition, when two or more kinds of compounds having a high concentration or different absorption wavelengths are mixed, the region of the absorption wavelength and the region of the emission wavelength are easily overlapped, and the emitted light is absorbed again, thereby increasing the luminance. This is because the case where the improvement effect is low can be avoided. Moreover, it is because the remarkable chromaticity change of backlight light can be prevented because the upper limit of light emission wavelength exists in the area | region of 600 nm or less. The emission wavelength is more preferably 380 to 550 nm.

  The white reflective film of the present invention contains a UV absorber and / or a light stabilizer within the range that does not impair the effects of the present invention in the binder resin that forms the resin layer provided on the white film, thereby providing a backlight. Because it can prevent the deterioration of white films (for example, optical deterioration such as yellowing or degradation deterioration that lowers the molecular weight) caused by light emitted from lamps such as cold-cathode tubes, especially ultraviolet rays, when used as preferable. In addition, if an ultraviolet absorber having a UV absorption band in a region that does not overlap with an absorption band in the UV region of the compound corresponding to the above (i) and (ii) is selected, a luminance improving effect is obtained. It is possible to impart both the white film and the effect of preventing the deterioration of the compound corresponding to the above (i) and (ii) by ultraviolet rays while exhibiting the effect of suppressing the change in chromaticity. .

The resin layer according to the present invention is not particularly limited, but a binder resin mainly composed of an organic component is preferable. For example, polyester resin, polyurethane resin, acrylic resin, methacrylic resin, polyamide resin, polyethylene resin, polypropylene resin, polyvinyl chloride Examples of the resin include polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, and fluorine resin.
These resins may be used alone, or two or more copolymers or a mixture thereof may be used. Among these, polyester resins, polyurethane resins, acrylic or methacrylic resins are preferably used in terms of heat resistance, additive dispersibility, productivity, and gloss. In terms of the light resistance of the resin layer, it is more preferable that the binder resin contains an ultraviolet absorber and a light stabilizer.

  Such ultraviolet absorbers and light stabilizers are roughly classified into inorganic and organic types, but the form to be contained is not particularly limited, and a method such as mixing with a binder resin that forms such a resin layer. However, when it is desired to prevent bleed out from the resin layer, a method such as copolymerization with a binder resin forming the resin layer may be used.

  As such inorganic ultraviolet absorbers, titanium oxide, zinc oxide, cerium oxide, etc. are generally known, and at least one selected from the group consisting of zinc oxide, titanium oxide and cerium oxide is bleed out. It is preferably used from the viewpoints of economy, light resistance, ultraviolet absorption, and photocatalytic activity. Several kinds of such ultraviolet absorbers may be used in combination as required, and these inorganic ultraviolet absorbers may exist in the form of porous particles. Of these, zinc oxide is most preferable from the viewpoints of economy, ultraviolet absorption, and photocatalytic activity. As such zinc oxide, FINEX-25LP, FINEX-50LP (manufactured by Sakai Chemical Industry Co., Ltd.) or the like can be used.

Examples of such organic ultraviolet absorbers include benzotriazole and benzophenone. Since these ultraviolet absorbers only absorb ultraviolet rays and cannot capture organic radicals generated by ultraviolet irradiation, the white films may be chain-degraded by these radicals.
In order to capture these radicals and the like, a light stabilizer is preferably used in combination, and a hindered amine (HALS) compound is preferably used as the light stabilizer.

  Here, as the copolymerization monomer for fixing the organic ultraviolet absorber and / or the light stabilizer, vinyl monomers such as acrylic and styrene are highly versatile and economically preferable. Among these copolymerizable monomers, since the styrene vinyl monomer has an aromatic ring and is easily yellowed, copolymerization with an acrylic vinyl monomer is most preferably used in terms of light resistance.

  As the benzotriazole substituted with a reactive vinyl monomer, 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole (trade name: RUVA-93); Otsuka Chemical ( In addition, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine (“Adeka Stab LA-82”) can be used in which a hindered amine compound is substituted with a reactive vinyl monomer. "; Manufactured by ADEKA Co., Ltd.) can be used.

  In the present invention, the organic ultraviolet absorber includes a resin containing an organic ultraviolet absorber such as benzotriazole or benzophenone, a resin copolymerized with a benzotriazole-based or benzophenone-based reactive monomer, or a hindered amine. A resin containing and / or copolymerizing a light stabilizer such as a (HALS) -based reactive monomer can be used within a range that does not impair the effects of the present invention.

  Organic UV-absorbing resins containing a resin obtained by copolymerizing such benzotriazole-based and benzophenone-based reactive monomers, and further a resin copolymerized with a hindered amine (HALS) -based reactive monomer are thin and have a high UV-absorbing effect. More preferred.

  These production methods and the like are disclosed in detail in JP-A-2002-90515 [0019] to [0039]. Among them, HALS HYBRID (registered trademark) (manufactured by Nippon Shokubai Co., Ltd.) containing an acrylic monomer and UV absorber copolymer as an active ingredient can be used.

  The content of the compound corresponding to the above (i) in the resin layer according to the present invention is not particularly limited as long as the effect of chromaticity change is obtained, and also the type, dispersibility, productivity, etc. of this compound However, it is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, more preferably 0%, based on the entire resin layer containing this compound. .5% by mass or more. What is necessary is just to select the content rate of the compound applicable to said (i) the quantity with a favorable balance with the brightness improvement effect and the chromaticity change of backlight light. When the content of the compound is less than 0.05% by mass, the effect of improving chromaticity may not be obtained. Moreover, although an upper limit is not specifically limited, If it exceeds 5 mass%, since the inhibitory effect of the chromaticity change of a backlight light may become small, it is preferable to control to 5 mass% or less.

  The content of the compound corresponding to the above (ii) in the resin layer according to the present invention is not particularly limited as long as luminance improvement is obtained, and also depends on the type, dispersibility, productivity, etc. of this compound. However, it is preferably 0.2% by mass or more, more preferably 1% by mass or more, more preferably 3% by mass, particularly preferably, based on the entire resin layer containing this compound. Is 10% by mass or more, and most preferably 30% by mass or more. The content of the compound may be selected so that the balance between the brightness enhancement effect and the change in chromaticity of the backlight light is good. When the content of the compound is less than 0.2% by mass, the brightness enhancement effect may not be obtained. The upper limit is not particularly limited, but if it exceeds 75% by mass, the productivity may be inferior or the chromaticity change of the backlight light may become extremely large. Therefore, the upper limit is controlled to 75% by mass or less. Is preferred.

  Although the thickness of the resin layer containing the compound corresponding to the above (i) and (ii) according to the present invention depends on the type and content of the compound, it cannot be uniquely limited. The thickness is preferably 50 μm or more, more preferably 1 to 15 μm, and particularly preferably 1 to 5 μm. When the thickness of the resin layer is less than 0.05 μm, the brightness enhancement effect may not be obtained or the light resistance may be insufficient. On the other hand, if the thickness exceeds 50 μm, the luminance may decrease or the chromaticity change of the backlight light may become extremely large, which is not preferable from the viewpoint of economy. In addition, the thickness of the resin layer here means the total thickness of the resin layer containing the compound corresponding to the above (i) and (ii), and when having one or more layers, the total thickness of each resin layer It is a value. However, when particles are included in the resin layer, the thickness of each layer is determined by selecting a location where no particles exist in the thickness direction.

  The white film according to the present invention should have a high visible light reflectance, and for this purpose, a white film containing bubbles inside is preferably used. Examples of these white films include, but are not limited to, porous unstretched or biaxially stretched polypropylene films and porous unstretched or stretched polyethylene terephthalate films. Regarding these production methods and the like, JP-A-8-262208 [0034] to [0057], JP-A 2002-90515 [0007] to [0018], JP-A 2002-138150 [0008] to [0034]. And the like. Among them, a porous white biaxially stretched polyethylene terephthalate film disclosed in JP-A-2002-90515, and a porous white biaxially stretched mixture and / or copolymerized with polyethylene naphthalate from the viewpoint of heat resistance and reflectance. A polyethylene terephthalate film is particularly preferred as the white film according to the present invention for the reasons described above.

  The configuration of the white film according to the present invention may be appropriately selected depending on the intended use and required characteristics, and is not particularly limited. However, the white film has a configuration of at least one layer and / or two or more layers. A composite film is preferable, and it is preferable that at least one layer thereof contains at least one of bubbles, inorganic particles, and organic particles.

  An example of a single layer configuration (= 1 layer) is, for example, a white film having only a single layer, and includes a configuration in which one or more of bubbles, inorganic particles, and organic particles are contained in the single layer. . In addition, as an example of a two-layer structure, a white film having a two-layer structure of A layer / B layer in which a B layer is laminated on an A layer. In at least one of these A layer and B layer, bubbles, inorganic The thing of the structure containing any 1 or more types of particle | grains and organic particle | grains is mentioned. Further, as an example of the three-layer structure, there is a white film having a three-layer structure in which three layers of A layer / B layer / A layer and A layer / B layer / C layer are laminated, and at least one of each layer A layer having one or more of bubbles, inorganic particles, and organic particles is included in the layer. In the case of a three-layer configuration, the B layer is most preferably a layer containing bubbles from the viewpoint of productivity.

  The number average particle diameter of the inorganic fine particles and / or organic particles contained in the white film is preferably 0.3 to 2.0 μm. As such organic particles, resins mainly composed of a high-melting cross-linked polymer component are preferable. For example, polyester resin, polyamide resin particles such as benzoguanamine, polyurethane resin, acrylic resin, methacrylic resin, polyamide resin, polyethylene resin, polypropylene Examples thereof include resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl acetate resins, fluorine-based resins, silicone resin particles, and hollow particles thereof. These resins may be used alone, or two or more copolymers or a mixture thereof may be used. Examples of the inorganic particles include calcium carbonate, magnesium carbonate, zinc carbonate, titanium oxide, zinc oxide, cerium oxide, magnesium oxide, barium sulfate, zinc sulfide, calcium phosphate, silica, alumina, mica, titanium mica, talc, clay, Kaolin, lithium fluoride, calcium fluoride, or the like can be used.

  As an example of such a white film, as a white film having a single layer structure, Lumirror (registered trademark) E20 (manufactured by Toray Industries, Inc.), SY64, SY70 (manufactured by SKC), White Lefster (registered trademark) WS- 220 (manufactured by Mitsui Chemicals, Inc.) and the like, and as a two-layer white film, Tetron (registered trademark) film UXZ1, UXSP (manufactured by Teijin DuPont Films Co., Ltd.), PLP230 (manufactured by Mitsubishi Plastics Co., Ltd.) Examples of white films having a three-layer structure include Lumirror (registered trademark) E60L, E6SL, E6SR, E6SQ, E6Z (manufactured by Toray Industries, Inc.), Tetron (registered trademark) film UX (Teijin DuPont Films, Inc.) ))). Moreover, as an example of a white sheet having a configuration other than these, Optilon ACR3000, ACR3020 (manufactured by DuPont), MCPET (registered trademark) (manufactured by Furukawa Electric Co., Ltd.) can be mentioned.

  Various additives can be added to the white film and / or the binder resin of the resin layer according to the present invention as long as the effects of the present invention are not impaired. Examples of additives include cross-linking agents, flame retardants, flame retardant aids, heat stabilizers, oxidation stabilizers, organic lubricants, antistatic agents, nucleating agents, dyes, fillers, dispersants, and coupling agents. Can be used.

  In the white reflective film of the present invention, the average reflectance at a wavelength of 400 to 700 nm measured from the surface provided with the resin layer is preferably 85% or more, more preferably 87% or more, and further preferably 90% or more. Most preferably, it is 95% or more. When the average reflectance is less than 85%, the luminance may be insufficient depending on the applied liquid crystal display. In addition, when the resin layer is provided in both surfaces, the average reflectance measured from any resin layer should just be 85% or more. As a method for setting the average reflectance at a wavelength of 400 to 700 nm to 85% or more, for example, there is a method of increasing the absolute amount of the light reflecting interface in the white film or the resin surface. In particular, methods such as forming more void structures in the above-described white film or increasing the thickness of the portion having the void structure can be mentioned.

  In the present invention, the surface on which the resin layer is provided is not particularly limited, and the white film has a two-layer structure of A layer / B layer, A layer / B layer / A layer or A layer / B layer / C layer 3 In the case of a layer structure, it may be provided on either side.

  In the present invention, the resin layer containing the compounds corresponding to the above (i) and (ii) can be formed by any method when forming on at least one side of the white film. ) And (ii) using various coating methods such as gravure coating, roll coating, spin coating, reverse coating, bar coating, screen coating, blade coating, air knife coating and dipping. Applicable at the time of white film production (in-line coating), formed by a method of providing a coating layer by applying on the white film after completion of crystal orientation (off-line coating), or corresponding to the above (i) and (ii) Examples of methods include laminating films and sheets containing compounds by lamination, etc. The present invention is not limited to.

  The white reflective film of the present invention thus obtained can improve the luminance of the liquid crystal backlight. Further, according to a preferred embodiment, the reflectance is little lowered even when used for a long time. Therefore, the white reflective film of the present invention can be suitably used as a reflector for an edge light type backlight for liquid crystal displays and a reflector for an edge light type or direct type backlight. In addition, it can be suitably used as a reflection plate for various surface light sources and a sealing film for solar cell modules that require reflection characteristics.

  The measurement method and evaluation method are shown below.

(1) Structural identification of compound of resin layer First, the resin layer of the sample is immersed in an organic solvent, and the resin layer is peeled and collected. Thereafter, the organic solvent after the resin layer is immersed is filtered. If there is filter cake, select a solvent having high solubility in the filter cake and dissolve it again. Next, a separable method is selected from general chromatography represented by silica gel column chromatography, gel permeation chromatography, liquid high-performance chromatography, gas chromatography, etc., and the filtrate and the redissolved filtrate solution are each simply used. Separate and purify into one substance. If it is difficult to separate by combining with other components in the resin layer, it is used as it is. Thereafter, each substance is appropriately concentrated and diluted, and nuclear magnetic resonance spectroscopy ( ¹ H-NMR, ¹³ C-NMR), two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR), infrared spectrophotometry (IR), Mass spectrometry (Mass), X-ray diffraction (XRD), Neutron diffraction (ND), Low-energy electron diffraction (LEED), High-speed reflection electron diffraction (RHEED), Atomic absorption spectrometry (AAS), Ultraviolet Photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence elemental analysis (XRF), inductively coupled plasma emission spectroscopy (ICP-AES), electron beam microanalyzer (EPMA), other elemental analysis, Thus, the structure was identified by appropriately selecting and combining the methods.

(2) Particle pore shape and particle shape in the resin layer The sample was cut in a direction perpendicular to the film plane at a knife inclination angle of 3 ° using a rotary microtome manufactured by Nippon Microtome Laboratories. Using the scanning electron microscope ABT-32 manufactured by Topcon Corporation, the obtained film cross section is, for example, at an observation magnification of 2500 to 10,000 times so that one particle is projected over the entire visual field region, and The image contrast was appropriately adjusted and observed, and the presence of pores and the shape of the particles were judged.

If the particles cannot be cut, the resin layer is immersed in an organic solvent, the coating layer is peeled and collected, and then the particles are removed from the resin layer by crimping and sliding on a slide glass to collect a sufficient amount of particles. . Subsequently, the obtained particles are used, for example, at an observation magnification of 2500 to 10,000 times so that one particle is projected over the entire visual field region using a scanning electron microscope ABT-32 manufactured by Topcon Corporation. Moreover, the contrast of the image was appropriately adjusted and observed, and the presence or absence of pores and the shape of the particles were judged.
Note that the presence / absence of pores is determined based on whether or not spots or spots are present in the particles in the observed image. There were no pores.

(3) Absorption wavelength of the compound in the resin layer The compound was separated and purified by one of the same methods as in (1) and then dissolved in various soluble solvents. Next, this solution was put in a quartz cell, and an absorption spectrum at a wavelength of 200 to 900 nm was measured using an ultraviolet-visible spectrophotometer (UV-Bis Spectrophotometer, model V-660 manufactured by JASCO Corporation). The concentration is adjusted as appropriate within the range in which each maximum absorption wavelength can be observed. If the maximum absorption wavelength is between 300 and 450 nm, the concentration is acceptable, and if it is on the short wavelength side less than 300 nm, it is unacceptable and longer than 450 nm The case where it exists in the wavelength side was set as the rejection 2.

(4) Emission wavelength of the compound in the resin layer The compound was separated and purified by any method similar to (1) and then dissolved in various soluble solvents. Next, this solution was put in a quartz cell, and using a spectrofluorometer (FP-6500 manufactured by JASCO Corporation), the maximum absorption wavelength obtained from (3) was irradiated as an excitation wavelength, An emission spectrum at a wavelength of 250 to 750 nm was measured. Concentration is adjusted so that the absorbance at the excitation wavelength is 1 when the optical path length is 1 cm. If the entire emission spectrum is between wavelengths 350-600 nm, pass 1; if it is between wavelengths 380-550 nm, pass 2. 2 is more preferable, when there is no light emission, or when a part of the emission spectrum is in the short wavelength region of less than 350 nm, fail A, and when part of the emission spectrum is in the longer wavelength region than wavelength 600 nm, reject B It was.

(5) Compound and particle content in resin layer The following method is selected according to the form of the resin layer.

(I) Resin layer not having a film such as a coating layer First, a sample is cut into a 30 cm square and its mass is measured. Next, the resin layer is immersed in an organic solvent, the mass of the sample after the resin layer is peeled and sampled is measured, the difference in the sample mass before and after the resin layer is peeled is calculated, and the value is the mass of the entire resin layer resin layer. And Further, each of the filtrate and the redissolved filtrate solution is separated and purified into a single substance by the same method as in (i) of (1). The isolates corresponding to the compounds and particles were concentrated and the total mass of each was measured. A value obtained by dividing the value of each total mass by the mass of the entire resin layer was obtained. Measurements were made at five locations in the same manner, and the average values at the five locations were defined as “compound content” and “particle content”.

(6) Thickness of resin layer First, the layer containing the compound of the sample is specified by the same method as in any one of (1). Next, the sample is cut in a direction perpendicular to the film plane at a knife inclination angle of 3 ° using a rotary microtome manufactured by Nippon Microtome Laboratory. The cross section of the obtained film was observed using a scanning electron microscope ABT-32 manufactured by Topcon Corporation, and the binder resin part containing only the binder resin or the compound containing only the compound in the resin layer laminated on the white film The total thickness of each layer is measured at five points on each side, and the average value is defined as “the thickness of the resin layer”.

(7) Refractive index difference between binder resin and particles in resin layer When the refractive index values of the binder resin and spherical particles were unknown, the difference was determined by the following procedure.
(I) After extracting the binder resin from the resin layer using an organic solvent, each filtrate and re-dissolved filtrate solution is separated and purified into a single substance by the same method as in (1), and the binder resin is obtained. After the corresponding purified product is appropriately distilled off, measurement is performed with respect to light having a wavelength of 589.3 nm at 25 ° C. by ellipsometry. This is carried out at five different places, and the average value of the five places is taken as the “refractive index of the binder resin” in this example.
(Ii) The resin layer of the white reflective film is immersed in an organic solvent, the resin layer is peeled off from the white film, and then the particles are dropped from the resin layer by pressing and sliding on a slide glass. The Becke line detection method is used to confirm that the particle outline is not visible at a temperature where the refractive index of each liquid organic compound is known, and the refractive index of the liquid organic compound used at this time is obtained. . This is carried out at five different locations, and the average value at the five locations is taken as the “particle refractive index” in this example.
(Iii) The difference between the refractive index value of the binder resin obtained from (i) and the refractive index value of the particles obtained from (ii) was obtained, and the value was defined as “the refractive index difference between the binder resin and the particles”. .

(8) Light resistance (yellowishness change Δb value)
A forced ultraviolet irradiation test was conducted under the following conditions using an ultraviolet deterioration accelerating tester iSuper UV Tester SUV-W131 (manufactured by Iwasaki Electric Co., Ltd.), and then the b value was determined. Three samples were subjected to an acceleration test, the b values before and after the test were measured, and the average value of the differences was defined as light resistance (yellowishness change Δb value).
"UV irradiation conditions"
Illuminance: 100 mW / cm ² , Temperature: 60 ° C., Relative humidity: 50% RH, Irradiation time: 48 hours Light resistance evaluation results are determined as follows. .
Class A: Yellowness change Δb value is less than 5
Class B: Yellowness change Δb value is 5 or more and less than 15
Class C: Yellowishness change Δb value is 15 or more.

(9) Average luminance, chromaticity change (Δx value, Δy value)
21 inch direct type backlight (using cold cathode tube, maximum emission wavelength of cold cathode tube at wavelength of 450 nm or less: 313 nm 365 nm 405 nm 436 nm, lamp tube diameter: 3 mmΦ, number of lamps: 12, distance between lamps: 25 mm, white reflective film And the distance between the lamp centers: 4.5 mm, and the distance between the diffusion plate and the lamp center: 13.5 mm), and the brightness and chromaticity were measured with the optical sheet configuration of the following two models.
Model 1: Diffusion plate RM803 (Sumitomo Chemical Co., Ltd., thickness 2 mm) / Diffusion sheet GM3 (Kimoto Co., Ltd., thickness 100 μm) 2 sheets Model 2: Diffusion plate RM803 (Sumitomo Chemical Co., Ltd., thickness 2 mm) / Diffusion sheet GM3 (manufactured by Kimoto Co., Ltd., thickness 100 μm) / prism sheet BEF-II (manufactured by 3M, thickness 130 μm) / polarized light separation sheet DBEF (manufactured by 3M, thickness 400 μm).

The measurement is performed by lighting the cold cathode ray tube for 60 minutes to stabilize the light source, and then using a color luminance meter BM-7fast (manufactured by Topcon Co., Ltd.) for luminance (cd / m ² ) and chromaticity (x value, y value). Was measured. For each value, an average value was calculated for three samples, and this was defined as average luminance and average chromaticity (x value, y value). Next, the difference between the obtained average chromaticity and the average chromaticity of the white film without the resin layer was taken, and this was defined as the chromaticity change (Δx value, Δy value).

Binder resins and compounds used in each example are shown below.
-Binder resin A: Acrylic resin (manufactured by Soken Chemical Co., Ltd. Foret GS-1000, 30% by mass solution)
-Binder resin B: Benzotriazole-containing acrylic copolymer resin (manufactured by Nippon Shokubai Co., Ltd. Hals Hybrid (registered trademark) UV-G720T concentration 40% by mass solution)
Compound A: Shigenox 103 (manufactured by Hackol Chemical Co., Ltd., structural formula: Structural formula (6) (Structural formula (1) Compound containing structure, R ₁ = phenyl group, R ₂ = heterocyclic substituted amino group) ))
Compound B: Hakkol PSR (manufactured by Hakkol Chemical Co., Ltd., structural formula: structural formula (7) below (compound containing the structural formula (1) structure, R ₁ = phenyl group, R ₂ = substituted heterocycle))
Compound C: Shigenox CL (manufactured by Hackol Chemical Co., Ltd., structural formula: Structural formula (8) (Structural formula (1) Compound containing structure, R ₁ = substituted heterocycle, R ₂ = carboethoxyamino group) ))
Compound D: UVITEX OB (manufactured by Ciba Specialty Chemicals Co., Ltd., structural formula: Structural formula (9) (compound containing structural formula (2), R ₃ = aryl group, R ₄ = tert-butyl group) )
Compound E: Kyaphor SN (manufactured by Nippon Kayaku Co., Ltd., structural formula: structural formula (10) below (compound containing structural formula (3), R ₅ = sodium sulfonate group, R ₆ = heterocyclic substituted amino) Group, R ₇ = hydrogen))
Compound F: 1,8-naphthalimide (manufactured by Tokyo Chemical Industry Co., Ltd., structural formula: structural formula (11) (compound containing structural formula (4)))
Compound G: Anthracene (manufactured by Tokyo Chemical Industry Co., Ltd., structural formula: structural formula (12) below (compound containing structural formula (5)))
Compound H: Eastobrite OB-1 (manufactured by Eastman Chemical Company, structural formula: Structural formula (13) below (compound containing structural formula (2) and structural formula (3), R ₃ = structure (3), R ₄ = Hydrogen, R ₅ = hydrogen, R ₆ = structure (2), R ₇ = hydrogen))
Compound I: Hostalux KS (manufactured by Clariant Japan Co., Ltd., structural formula: structural formula (14) below (compounds including structural formula (2) and structural formula (3), R ₃ = structure (3), R ₄ = Methyl group or hydrogen, R ₅ = hydrogen, R ₆ = structure (2), R ₇ = hydrogen))
Compound J: Naphthalene (manufactured by Tokyo Chemical Industry Co., Ltd., structural formula: Structural formula (15) below (compounds not including any of the structural formulas (1) to (5)))
Compound K: Quinacridone (manufactured by Tokyo Chemical Industry Co., Ltd., structural formula: Structural formula (16) below (compound not including any structure of structural formula (1) to structural formula (5)))
Particle A: Nonporous spherical acrylic particles (“TECHPOLYMER” (registered trademark) SSX series, SSX-105, refractive index 1.49, average volume particle diameter 5.0 μm, manufactured by Sekisui Plastics Co., Ltd.)
Particle B: Porous amorphous silicon oxide (silica) particles (Silo Hovic 100, refractive index 1.45, average volume particle diameter 2.5 μm, manufactured by Fuji Silysia Chemical Ltd.)
-Particle C: Porous amorphous calcium phosphate particles (HAP manufactured by Maruo Calcium Co., Ltd., refractive index 1.63, average volume particle diameter 1.2 μm)
Particle D: Porous spherical acrylic particles (“TECHPOLYMER” MBP series, MBP-8, refractive index 1.49, average volume particle diameter 8.0 μm, manufactured by Sekisui Plastics Co., Ltd.)
Particle E: Porous spherical silicon oxide (silica) particles (Fuji Silysia Chemical Co., Ltd., Pyrospher C-1504, refractive index 1.45, average volume particle diameter 4.5 μm)

( Reference Example 1)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: “Compound A” 0.17 g
Compound 2: 4.51 g of “Compound E”
・ Particle: None ・ Solvent: “Toluene” 68.73 g
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

( Reference Example 2)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: “Compound A” 0.22 g
Compound 2: “Compound E” 13.58 g
・ Particle: None ・ Solvent: 105.18 g of “Toluene”
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 44, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 13. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

( Reference Example 3)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: 0.07 g of “Compound A”
Compound 2: “Compound E” 4.49 g
・ Particle: None ・ Solvent: “Toluene” 68.25 g
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

( Reference Example 4)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: 0.02 g of “Compound A”
Compound 2: “Compound E” 4.49 g
・ Particles: None ・ Solvent: “Toluene” 68.03 g
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

( Reference Example 5)
Except that the compound 2 to be used was changed to the compound F, it was prepared in the same manner as in Example 1, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain a white reflective film of the present invention. .

( Reference Example 6)
Except that the compound 2 to be used was changed to the compound G, it was prepared in the same manner as in Example 1, and a resin layer having an application amount after drying of 4.0 g / m ² was provided to obtain the white reflective film of the present invention. .

(Example 7)
Except that the compound 2 to be used was changed to the compound H, it was prepared in the same manner as in Example 1, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain a white reflective film of the present invention. .

(Example 8)
Except that the compound 2 to be used was changed to the compound I, it was prepared in the same manner as in Example 1, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain the white reflective film of the present invention. .

( Reference Example 9)
Except that the compound 1 to be used was changed to the compound D, it was prepared in the same manner as in Example 1, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain the white reflective film of the present invention. .

(Example 10)
Except that the compound 2 to be used was changed to the compound H, it was prepared in the same manner as in Example 9, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain a white reflective film of the present invention. .

(Example 11)
Except that the compound 1 to be used was changed to the compound B, it was prepared in the same manner as in Example 7, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain a white reflective film of the present invention. .

(Example 12)
Except that the compound 1 to be used was changed to the compound C, it was prepared in the same manner as in Example 7, and a resin layer having a coating amount of 4.0 g / m ² after drying was provided to obtain the white reflective film of the present invention. .

(Example 13)
・ Binder resin: "Binder resin B" 100.00g
Compound 1: “Compound A” 0.29 g
Compound 2: 7.48 g of “Compound H”
・ Particles: 9.78 g of “Particle A”
・ Solvent: 170.22 g of “Toluene”
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Example 14)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: “Compound A” 0.22 g
Compound 2: “Compound H” (5.61 g)
・ Particles: 7.34 g of “Particle B”
・ Solvent: "Toluene" 102.66g
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Example 15)
A white reflective film of the present invention was obtained by preparing in the same manner as in Example 14 except that the particles to be used were changed to particles C, and providing a resin layer having a coating amount after drying of 4.0 g / m ² .

(Example 16)
A white reflective film of the present invention was obtained by preparing in the same manner as in Example 14 except that the particles to be used were particles D, and providing a resin layer having a coating amount of 4.0 g / m ² after drying.

(Example 17)
A white reflective film of the present invention was obtained by preparing in the same manner as in Example 14 except that the particles to be used were changed to particles E, and providing a resin layer having a coating amount of 4.0 g / m ² after drying.

(Example 18)
・ Binder resin: "Binder resin B" 100.00g
Compound 1: “Compound A” 0.23 g
Compound 2: 3.20 g of “Compound H”
・ Particles: “Particle E” 2.29 g
・ Solvent: "Toluene" 122.86g
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 20, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 6. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Example 19)
・ Binder resin: "Binder resin B" 100.00g
Compound 1: “Compound A” 0.23 g
Compound 2: "Compound H" 1.87 g
・ Particles: 4.68g “Particle E”
・ Solvent: 127.13 g of “Toluene”
A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Comparative Example 1)
A three-layer thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was used as a white reflective film without providing a resin layer.

(Comparative Example 2)
・ Binder resin: "Binder resin B" 100.00g
・ Compound 1: None ・ Compound 2: None ・ Particles: None ・ Solvent: “Toluene” 100.00 g
Was added with stirring to make a coating solution.

A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The coating solution was applied to both sides of the white substrate film using a bar coater count 13 manufactured by Matsuo Sangyo Co., Ltd., and dried by heating at 120 ° C. for 1 minute. A resin layer of only 0 g / m ² binder resin was provided to obtain a white reflective film of the present invention.

(Comparative Example 3)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: 4.48 g of “Compound H”
・ Compound 2: None ・ Particles: None ・ Solvent: “Toluene” 67.93 g
A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Comparative Example 4)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: “Compound A” 0.15 g
・ Compound 2: None ・ Particles: None ・ Solvent: “Toluene” 50.60 g
A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Comparative Example 5)
Except that the compound 1 to be used was changed to the compound D, it was prepared in the same manner as in Comparative Example 4, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain the white reflective film of the present invention. .

(Comparative Example 6)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: “Compound A” 0.15 g
Compound 2: “Compound D” 0.15 g
・ Particle: None ・ Solvent: 51.21 g of “Toluene”
A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Comparative Example 7)
Except that the compound 1 to be used is compound E and the compound 2 to be used is compound H, a resin layer having a coating amount of 4.0 g / m ² after drying was prepared in the same manner as in Example 1. An inventive white reflective film was obtained.

(Comparative Example 8)
・ Binder resin: "Binder resin A" 100.00g
Compound 1: “Compound E” 0.22 g
Compound 2: “Compound H” (5.61 g)
・ Particles: 7.34 g of “Particle A”
・ Solvent: "Toluene" 102.66g
A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Comparative Example 9)
Except that the compound 1 to be used was changed to the compound E, it was prepared in the same manner as in Example 17, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain a white reflective film of the present invention. .

(Comparative Example 10)
・ Binder resin: "Binder resin A" 100.00g
-Compound 1: "Compound J" 5.57g
-Compound 2: None-Particles: 7.29 g of "Particle E"
・ Solvent: 101.43 g of “toluene”
A three-layered thermoplastic resin film (Lumirror (registered trademark) E6SR, manufactured by Toray Industries, Inc., thickness 225 μm) composed of porous biaxially stretched polyethylene terephthalate was prepared as a white film. The said coating liquid is apply | coated to the single side | surface of this base material white film using the Matsuo Sangyo Co., Ltd. bar coater count 13, and it heat-drys at 120 degreeC for 1 minute, and the coating amount after drying is 4. A white reflective film of the present invention was obtained by providing a resin layer of 0 g / m ² .

(Comparative Example 11)
Except that the compound 1 to be used was changed to the compound K, it was prepared in the same manner as in Comparative Example 10, and a resin layer having a coating amount after drying of 4.0 g / m ² was provided to obtain a white reflective film of the present invention. .

  In any of Examples 1 to 19, it was possible to suppress a change in chromaticity while having a luminance improvement effect. In particular, when the compound corresponding to (ii) has the structures of structural formula (2) and structural formula (3) in its structure, the compound corresponding to (i) has the structural formula (1) or (2 ) (Examples 7, 8, and 10), and even if a substituent is bonded to the structure (Examples 11 and 12), both can provide a high brightness enhancement effect. It was.

When the compound corresponding to (i) and the compound corresponding to (ii) are both contained (Examples 1 to 6)
9), any combination of compounds corresponding to (i) and (ii), when containing only one or more compounds corresponding to (i) or (ii) (Comparative Example) Compared with 3-7), a brightness improvement effect and a suppression effect of chromaticity change were obtained. Moreover, when the content rate of the compound in a resin layer was high and the resin layer was thick, although the chromaticity change increased proportionally, the brightness improvement effect became higher (Example 2). Furthermore, various particles are added to the resin layer together with the compounds corresponding to (i) and (2), and the brightness of the particles is changed by changing the pore mode, shape, refractive index difference from binder resin, and content rate. The improvement effect and the suppression effect of the chromaticity change can be easily changed and adjusted (Examples 13 to 19). In addition, when the binder resin in the resin layer contained an ultraviolet absorber and a light stabilizer (Examples 13, 18, and 19), the light resistance was also good.

  When the resin layer was not provided (Comparative Example 1) or even when the resin layer was provided, the brightness enhancement effect was not obtained when the compound was not contained (Comparative Example 2). When only one compound corresponding to (i) is contained (Comparative Examples 4 and 5) and when two compounds are contained (Comparative Example 6), the brightness enhancement effect is poor, and conversely, only compounds corresponding to (ii) are contained. When 1 type was contained (Comparative Example 3) or 2 types (Comparative Examples 7 to 9), even if particles were contained, the luminance improvement effect was obtained, but the chromaticity change was large.

  When the compound contained in the resin layer does not have any of the structures of the structural formulas (1), (2), (3), (4), and (5) in its structure, the maximum absorption wavelength is extreme. In the case where the light is not in the short wavelength region and does not emit light, the luminance enhancement effect is not obtained (Comparative Example 10), and when the maximum absorption wavelength and the light emitting region are in the extremely long wavelength region (Comparative Example 11), In addition to absorbing the light in the visible region, the luminance is lowered and the chromaticity change is extremely increased.

  The present invention relates to a white reflective film for a backlight member for a liquid crystal display. More specifically, an edge light type backlight lamp reflector for liquid crystal displays, an edge light type and / or direct type type backlight for a liquid crystal display, a white reflective film, a solar cell module sealing film, The present invention relates to a white reflective film for a back sheet. Besides, white film for solar cell module sealing film and back sheet, paper replacement, ie card, label, sticker, home delivery slip, video printer image paper, inkjet, barcode printer image paper, poster, map, Dust-free paper, display board, white board, thermal transfer, offset printing, telephone card, IC card, etc. receiving sheet base material, wallpaper and other building materials, indoor and outdoor lighting and indirect lighting equipment, It is a white film for use in electronic parts such as components mounted on automobiles, railways, aircraft, etc. and circuit materials.

1: White reflective film 2: Substrate white film having a three-layer structure 3: Resin layer containing compound 4: Coating layer containing compound 5: Adhesive layer containing compound 6: Resin film containing compound 8: Compound Particles larger than the coating layer thickness containing 9: Particles smaller than the coating layer thickness containing the compound 10: Particles smaller than the adhesive layer thickness containing the compound 11: Particles larger than the adhesive layer thickness containing the compound 12: Containing the compound Particles smaller than thickness of resin film 13: Particles larger than thickness of resin film containing compound

Claims (4)

At least one resin layer containing a compound corresponding to the following (i) and a compound corresponding to the following (ii) is laminated on at least one surface of the white film,
The content of the compound corresponding to (i) is 0.05% by mass or more and 5% by mass or less with respect to the entire resin layer,
Content of the compound applicable to (ii) is 4 mass% or more and 13 mass% or less with respect to the whole resin layer, The white reflective film characterized by the above-mentioned.
(I) A compound having the following structure (1) and / or (2) in the molecule and not having the following structures (3), (4) and (5) in the molecule.
(Ii) A compound having the following structures (2) and (3) in the same molecule .

(R ₁ = aryl group having 6 to 12 carbon atoms, hydrogen. R ₂ = carbon having 1 to 7 elements other than carbon and hydrogen, and heterocycle having 1 to 7 elements other than carbon and hydrogen. A substituted heterocyclic ring to which an aryl group of 6 to 12 is bonded, an amino group, a substituted amino group to which an ester group having 2 to 5 carbon atoms is bonded, and a substituent having any element of oxygen, nitrogen, halogen, and sulfur A substituted amino group bonded to a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, and the heterocyclic ring bonded thereto, hydrogen R ₃ = a heterocyclic ring having 1 to 7 elements other than carbon and hydrogen, structure ( 3) Carbon and hydrogen to which R ₆ is bonded R ₄ = C 1-6 linear / branched / cyclic alkyl group, hydrogen R ₅ and R ₇ = sulfonic acid group, hydrogen R ₆ = amino Group, oxygen, nitrogen, halogen, or sulfur Carbon substituents wherein the carbon and substituted amino groups in which the heterocycle is bonded to the heterocyclic ring is bonded with an element number 1-7 other than hydrogen, the R ₃ structure (2) are attached, hydrogen.) Backlight lamp reflector which is configured using a white reflective film according to claim 1. Backlight is configured using a white reflective film according to claim 1. The film for solar cell sealing which used the white reflective film of Claim 1 in order to seal a solar cell module.

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