WO2010018878A1 - Reflective film for illuminating device - Google Patents

Abstract

A reflective film for illuminating devices, which is characterized in that the reflective film is composed of a white film and transparent projections each formed on the surface of the white film and having a height of 3-50 μm, and in that the coverage of the white film surface by the transparent projections is 50-100%.  High luminance can be achieved when the reflective film for illuminating devices is used as a reflective film in a backlight unit of a backlight-type liquid crystal display device.

Description

Reflective film for lighting equipment

The present invention relates to a reflective film used in an illuminating device, and more particularly to a reflective film for an illuminating device used as a reflective film of a backlight unit of a liquid crystal display device.

Liquid crystal display devices include a backlight system in which a light source is placed on the back of a backlight unit and a sidelight system in which a light source is placed on a side surface. In either method, a reflective film is installed on the back surface of the backlight unit in order to prevent light from the light source from escaping to the back surface of the screen. This reflective film is required to have a thin and high reflectance.
Conventionally, as this reflective film, a white film in which a white pigment is added to polyester (Japanese Patent Laid-Open Nos. 2004-0050479 and 2004-330727), and a white film containing fine bubbles inside (Japanese Patent Laid-Open No. No. 322153 and JP-A-7-118433 have been used.
In a backlight type liquid crystal display device, improvement in luminance can be achieved to some extent by improving the reflectance of the reflective film, but there is a limit only by improving the reflectance.
In addition to improving the reflectance of the film itself, as a measure to improve the brightness, it has been studied to add a fluorescent whitening agent to the reflective film, and coating the surface of the reflective film with the fluorescent whitening agent It has been proposed (Japanese Patent Laid-Open No. 2002-40214). However, since a cold cathode tube is generally used as a light source in the backlight unit, when a fluorescent whitening agent is coated on the surface of a white film, the fluorescent whitening agent is absorbed by ultraviolet rays emitted from the cold cathode ray tube. The effect of improving the reflectivity is lost over time. In order to prevent the deterioration of the fluorescent whitening agent due to ultraviolet rays, the fluorescent whitening agent is excited by ultraviolet rays and emits blue light in the first place. The effect of improving the reflectance by the white agent cannot be obtained.

When the specular reflection of the reflective film is strong, the present inventor returns reflected light to the light source installed in front of the reflective film in the backlight unit, that is, between the reflective film and the display surface, and the light is displayed. We paid attention to the fact that the loss of light was caused because it did not reach the surface, causing the brightness to decrease.
When the present invention is used as a reflective film in a backlight unit of a backlight type liquid crystal display device by suppressing specular reflection by a reflective film and providing reflected light with directivity that avoids a light source in front of the reflected light. Another object of the present invention is to provide a reflection film for a lighting device that can obtain high brightness.
The second object of the present invention is to provide a reflective film for an illuminating device that can obtain high luminance when used as a reflective film in a backlight unit of a backlight type liquid crystal display device and is excellent in workability. There is.
The third object of the present invention is to obtain high luminance when used as a reflective film in a backlight unit of a backlight type liquid crystal display device, and to suppress yellowing over time with little color shift. Another object of the present invention is to provide a reflective film for a lighting device.

That is, the present invention comprises a white film and a transparent protrusion having a height of 3 to 50 μm provided on the surface of the white film, and the coverage by the transparent protrusion on the surface of the white film is 50 to 100%. It is a reflection film for lighting devices.
In a preferred embodiment of the present invention, the transparent protrusion is made of transparent particles, and the transparent film having an exposure rate of 5 to 100% covers the surface of the white film at a coverage of 50 to 100% on the surface of the reflective film. including. That is, the present invention comprises a white film and transparent protrusions having a height of 3 to 50 μm by transparent particles covering the surface of the white film, and 50 to 100 transparent particles having an exposure rate of 5 to 100% on the surface of the white film. The reflective film for lighting devices which coat | covers the white film surface with the coverage of 100% is included as a preferable aspect.

ADVANTAGE OF THE INVENTION According to this invention, the reflection film for illuminating devices which can obtain high brightness | luminance when it uses as a reflection film for the backlight unit of a liquid crystal display device of a backlight system can be provided.
Secondly, according to the present invention, there is provided a reflection film for a lighting device that can obtain high luminance when used as a reflection film in a backlight unit of a backlight type liquid crystal display device and is excellent in workability. be able to.
Third, according to the present invention, when used as a reflective film in a backlight unit of a backlight type liquid crystal display device, high luminance can be obtained, and there is little color shift, and yellowing with time is suppressed. It is possible to provide a reflective film for a lighting device.

It is a schematic diagram of the square thrust part of the metal mold | die used for formation of the square thrust type protrusion in Example 1-6. It is the shape of the prism-shaped unevenness | corrugation formed in an application layer, when forming an unevenness | corrugation in an application layer using the nip roller which provided the prism-shaped unevenness | corrugation in Example 1-7. It is a schematic diagram of the square thrust part of the metal mold | die used for formation of the square thrust type protrusion in Comparative Example 1-6. It is the shape of the prism-shaped unevenness | corrugation formed in an application layer, when forming an unevenness | corrugation in an application layer using the nip roller which provided the prism-shaped unevenness | corrugation in Comparative Example 1-7. It is a schematic diagram of the film cut surface cut | disconnected using the microtome in the measurement of the coverage of the film by a transparent protrusion. It is a schematic diagram of the cut surface of the film cut | disconnected using the microtome in the measurement of the coverage of the film by the transparent protrusion formed with the transparent particle. It is a schematic diagram of the cut surface of the film cut | disconnected using the microtome in the measurement of the coverage of the film by the transparent protrusion formed with the transparent particle.

Hereinafter, the present invention will be described in detail.
White film
The white film in the present invention is a film made of a thermoplastic resin and having a white colorant or a void-forming substance contained in the film so as to exhibit a white color.
Examples of the thermoplastic resin constituting the film include polyester, polyolefin, and polystyrene. Polyester is preferred from the viewpoint of achieving both mechanical properties and thermal stability.
When using polyester as a thermoplastic resin of a white film, polyester which consists of a dicarboxylic acid component and a diol component is used as polyester. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, adipic acid, and sebacic acid. Examples of the diol component include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and 1,6-hexanediol.
Among these polyesters, aromatic polyesters are preferable, and polyethylene terephthalate is particularly preferable. Polyethylene terephthalate may be a homopolymer, but a copolymer is preferred.
The white film may consist of a single layer or a plurality of layers. When a white film consists of a several layer, it is preferable that it is a laminated | multilayer film which consists of a white reflective layer which reflects light, and a support layer which supports this. In this laminated film, the white reflective layer is preferably a layer containing a relatively large amount of voids, and the support layer is preferably a layer containing relatively few voids or no voids. The polyester used for the white reflective layer is preferably a copolymer polyester, and the proportion of the copolymer component is, for example, 3 to 20 mol%, preferably 4 to 15 mol%, more preferably based on the total dicarboxylic acid component. 5 to 13 mol%. By setting the proportion of the copolymer component within this range, it is possible to obtain an excellent film forming property even for a white reflective layer containing a relatively large amount of voids, and a white film excellent in thermal dimensional stability can be obtained.
When the white film is composed of a plurality of layers, the white reflective layer preferably contains a phosphor. In this case, the phosphor content is preferably 0.1 to 7% by weight based on the weight of the white reflective layer. By containing in this range, the luminance can be improved without coloring the white reflective layer by the phosphor, and a reflective film capable of accurate color reproduction when used as a reflective film of an illumination device can be obtained.
As the phosphor, either an inorganic phosphor or an organic phosphor can be used. In order to maintain a stable fluorescence function over a long period of time, an inorganic phosphor is preferable. As the phosphor, for example, those described later can be used.
As the white colorant or void forming substance used for the white film, for example, inorganic particles and organic particles can be used.
As the white colorant, it is preferable to use white inorganic particles. When inorganic particles are used as the void-forming substance, it is preferable to use white inorganic particles. Examples of the white inorganic particles include barium sulfate, titanium dioxide, silicon dioxide, and calcium carbonate particles. The average particle size of the inorganic particles is, for example, 0.2 to 3.0 μm, preferably 0.3 to 2.5 μm, and more preferably 0.4 to 2.0 μm. By using inorganic particles having an average particle diameter in this range, it is possible to appropriately disperse in the polyester, and it is possible to obtain a film that does not easily aggregate particles and that does not have coarse protrusions. Glossiness can be controlled within an appropriate range without being too rough. The inorganic particles may have any particle shape, for example, a plate shape or a spherical shape. The inorganic particles may be subjected to a surface treatment for improving dispersibility.
When organic particles are used as the void-forming substance, resin particles that are incompatible with polyester are used as the organic particles. As the organic particles, silicone resin particles and polytetrafluoroethylene particles are preferable. The average particle diameter of the organic particles is, for example, 0.2 to 10 μm, preferably 0.3 to 8.0 μm, and more preferably 0.4 to 6.0 μm. By using the organic particles in this range, it is possible to obtain a film that can be appropriately dispersed in the polyester, is less likely to aggregate, and has no coarse protrusions.
From the viewpoint of obtaining high brightness, the light reflectance of the white film is preferably 95% or more, more preferably 96% or more, and particularly preferably 97% or more as the reflectance at a wavelength of 550 nm.
Transparent protrusion
The reflective film for lighting device of the present invention comprises a white film and a transparent protrusion having a height of 3 to 50 μm provided on the surface of the film. Transparent protrusions may be provided continuously or discontinuously.
In the present invention, the coverage by the transparent protrusions on the white film surface is 50 to 100%, preferably 60 to 100%, more preferably 70 to 100%, and particularly preferably 80 to 100%. If the coverage is less than 50%, the directivity of light that avoids the front light source is impaired, and improvement in luminance cannot be expected.
In the present invention, the coverage is measured with respect to a measurement area having a total length of 6 mm in a measurement area having a length of 3 mm in each of two orthogonal directions in the film plane, and the white film surface is covered with a transparent protrusion in the measurement area. Is defined as the percentage that is.
Specifically, using a microtome, a section is cut out so that the thickness direction of the film becomes a cut surface, and this section sample is made 3000 times using a Hitachi S-4700 field emission scanning electron microscope. And observe the measurement area with a total length of 6 mm in the measurement area with a length of 3 mm in each of the two orthogonal directions in the film plane, and add up the length of the part not covered with transparent protrusions in the measurement area And calculated by the following formula.
Coverage
= (6 mm- (integrated length of the portion not covered with the transparent protrusion (mm)))
/ 6mm x 100 (%)
In addition, when the largest diameter part of a transparent protrusion has come out outside the coating-film surface, it is considered that the part covered with the maximum diameter of a transparent particle is coat | covered with the transparent protrusion.
The transparent protrusion only needs to be formed of a transparent substance, and may be formed of any substance of an organic substance and an inorganic substance. Moreover, you may form with the mixture of organic substance and inorganic substance, and may form with the composite material of organic substance and inorganic substance. The light transmittance of the substance forming the transparent protrusions is, for example, 50% or more, preferably 60% or more, and more preferably 70% or more. The transparent protrusions are preferably those that do not absorb light in the visible region in order to prevent coloring.
The shape of the transparent protrusion is, for example, a dome shape or a pyramid shape, or a pyramid shape other than the pyramid shape, for example, a triangular pyramid shape, a hexagonal pyramid shape, an octagonal pyramid shape, and preferably a dome shape or a pyramid shape. Particularly preferred is a dome shape. The dome-shaped protrusion may be a protrusion having a smooth convex surface, and is preferably a hemispherical surface, a spherical surface or a part of a spheroid surface, and particularly preferably a hemispherical surface. The hemispherical surface does not necessarily have to be half of a sphere, and corresponds to a dome-shaped protrusion if a part of the spherical surface protrudes to the surface in a convex shape.
The pyramid shape means a square shape, but when the transparent protrusion is a pyramid shape, the length of one side of the bottom surface of each pyramid is preferably 5 to 50 μm. By setting the length of one side in this range, it is preferable to prevent the protrusions from dropping without impairing the effect of imparting directivity to the reflected light. The shape of the pyramid is preferably perfect quadrature, but may be a shape in which a part of the pyramid, for example, a vertex is cut off.
The height of the transparent protrusion in the present invention is 3 to 50 μm. If the height is less than 3 μm, the directivity of light cannot be obtained, and if it exceeds 50 μm, the projections may drop off or the effect of imparting directivity to reflected light may vary greatly depending on the backlight design, that is, the position of the light source. Will arise.
When the transparent protrusion has a dome shape, the average diameter of the bottom surface of each dome is preferably 5 to 50 μm. By setting the average diameter in this range, it is preferable that the protrusions can be prevented from dropping without impairing the effect of imparting directivity to the reflected light. In the case of a dome shape, the most preferable shape is a hemisphere.
Examples of organic substances that form transparent protrusions include UV curable resins, thermosetting resins, acrylic resins, silicone resins, styrene resins, and urethane resins. Acrylic resins and styrene resins are preferred because they hardly absorb light in the visible light region. As the inorganic substance forming the transparent protrusions, glass is preferable.
The transparent protrusions can be formed, for example, by placing a thermosetting resin or UV curable resin filled in a mold in accordance with the shape of the protrusions on the film, and thermosetting or UV curing, for example, It can be formed by supporting transparent particles on the surface of a white film with a binder. The former method is a preferable method when forming a pyramidal protrusion, and the latter method is a preferable method when forming a dome-shaped protrusion, which will be described in detail later.
When a UV curable resin is used as the curable resin, a radical capable of reacting a reactive group-containing compound such as a (meth) acryloyl group, a vinyl group, or an epoxy group with this reactive group-containing compound by UV irradiation, A mixture of a compound that generates an active species such as a cation can be used.
From the viewpoint of curing speed, a combination of a reactive group-containing compound (monomer) containing an unsaturated group such as a (meth) acryloyl group or a vinyl group and a radical photopolymerization initiator that generates a radical by UV light is preferable. Examples of the (meth) acryloyl group compound include phenoxyethyl (meth) acrylate, phenoxy-2-methylethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) acrylate, 2-phenylphenoxyethyl (meth) acrylate, 4-phenylphenoxyethyl (meth) acrylate, 3- (2-phenylphenyl) -2-hydroxypropyl (meth) acrylate, and p-cumylphenol reacted with ethylene oxide ( (Meth) acrylate, ethylene oxide-added bisphenol A (meth) acrylate, propylene oxide-added bisphenol A (meth) acrylate, bisphenol A diglycidyl ether and (meth) acrylate Bisphenol A epoxy (meth) acrylate obtained by epoxy ring opening with acid, bisphenol F epoxy (meth) acrylate obtained by epoxy ring opening reaction of bisphenol F diglycidyl ether and (meth) acrylic acid can be mentioned. .
Protrusion by transparent particles
The transparent protrusions in the reflective film for an illuminating device of the present invention are preferably supported by the surface of the white film and are made of transparent particles covering the surface of the white film. That is, the reflective film for an illumination device of the present invention is preferably composed of a white film and transparent particles covering the surface of the white film.
The transparent particles are composed of a curved surface or a shape composed of a curved surface and a plane in order to collect light. As this shape, for example, a spherical shape, a rugby ball shape, or a convex lens shape can be used. In order to effectively improve the luminance, an aspect ratio of 3 or less is preferable, and an aspect ratio of 1.2 or less is more preferable. A particularly preferred shape is a spherical particle. The aspect ratio is major axis / minor axis. The particle diameter of the transparent particles is a value obtained by taking the average of the major axis and the minor axis when the transparent particles are not spherical.
The size of the transparent particles forming the transparent protrusions is, for example, 3 to 50 μm, preferably 5 to 50 μm, more preferably 7 to 45 μm, particularly preferably 8 to 40 μm, as an average particle diameter measured with an electron microscope. The thickness is preferably 10 to 30 μm. By using transparent particles with an average particle diameter in this range, it is possible to form transparent protrusions with a height of 3 to 50 μm, and it is easy to control the directivity of light, and it is difficult for particles to fall off. In this case, it is possible to obtain a reflective film in which streak-like coating defects hardly occur.
The transparent particles have a volume 50% particle diameter D50 of 3 to 50 μm as measured by a particle size distribution meter, and a ratio of the volume 10% particle diameter D10 to the volume 90% particle diameter D90 of D10 / D90 is 0.00. It is preferably 30 to 0.98, more preferably 0.30 to 0.70. When the ratio D10 / D90 is within this range, it is possible to obtain a contribution to increasing the luminance without burying particles having a small particle size in the binder, and to prevent the particles having a large particle size from falling off. Can do. The larger the ratio D10 / D90, the sharper the particle size distribution. However, since it is difficult to obtain particles having a single particle size, the upper limit of the ratio D10 / D90 is, for example, 0.98.
Regarding the relationship between the height of the protrusion and the particle size of the transparent particle when the transparent protrusion is formed of transparent particles, for example, when the transparent protrusion is formed using transparent particles having an average particle diameter of 20 μm, the transparent particle is used as the binder. If it is supported on a white film in a half-buried state, the height of the transparent protrusion is 10 μm. If it is supported on the white film without being buried in the binder, the height of the transparent protrusion is 20 μm.
When the transparent protrusions are formed of transparent particles, the transparent protrusions formed by the transparent particles are 50 to 100%, preferably 60 to 100%, more preferably 70 to 100%, and particularly preferably 80 to 100%. The surface of the white film is coated at a coverage rate. That is, the reflective film of the present invention is a reflective film composed of a white film and transparent particles covering the surface of the white film, and 50 to 100 transparent particles having an exposure rate of 5 to 100% on the surface of the reflective film. The white film surface is coated with a coverage of%. If the coverage by the transparent particles is less than 50%, the directivity of light is impaired and an increase in luminance cannot be expected.
In the present invention, the coverage of the white film with transparent particles is observed for a measurement area of 6 mm in total in a measurement area of 3 mm in length in each of two orthogonal directions in the film plane. Defined as the percentage covered by transparent particles.
Specifically, using a microtome, the section sample 1 is cut out so that one direction randomly selected in the film plane and the thickness direction of the film become the cutting plane, and one random direction selected in the section sample 1 is selected. The slice sample 2 is cut out so that the direction perpendicular to the thickness direction and the thickness direction are cut surfaces, the region of the coating film surface of the binder of the slice sample 1 is 3 mm in length, and the length of the coating film surface of the binder of the slice sample 2 is 3 mm. The measurement region having a total length of 6 mm with respect to the above region was observed at a magnification of 3000 times using a S-4700 field emission scanning electron microscope manufactured by Hitachi, Ltd. The lengths of the portions of the film surface that are not covered with are integrated to obtain the following formula (see FIG. 7).
Coverage with transparent particles
= (6 mm- (integrated length of the portion not covered with transparent particles (mm)))
/ 6mm x 100 (%)
In addition, when the maximum diameter portion of the transparent particle is outside the coating surface on the cut surface, it is considered that the portion covered with the maximum diameter of the transparent particle is covered with the transparent particle, and the maximum diameter of the transparent particle If the part is inside the coating surface, that is, if it is sinking in the coating film, the maximum diameter of the dome-shaped protrusion formed by the portion of the transparent particle that is outside the coating film is covered with the particle. It is assumed that
In the calculation of the coverage with transparent particles, the transparent particles treated as covering the surface of the white film are those in which part or all of the transparent particles are exposed on the surface of the reflective film. This exposure means exposure at an exposure rate of 5 to 100%, preferably 10 to 100%, more preferably 20 to 100% as defined in the present invention. As described above, if the exposure rate is less than 5%, it is not possible to obtain the light condensing effect by the exposed particles according to the present invention if the exposure rate is less than 5%. Because.
In a preferred embodiment, the transparent particles are supported on the surface of the white film by a coating film of a binder provided on the surface of the white film. For this reason, a part of transparent particle is in contact with the coating film of a binder, or is sinking. The exposure rate of 100% corresponds to the situation where the white film surface and the transparent particle surface are in contact with each other on the cut surface, and the surface of the white film is supported by the binder. The exposure rate of 0% is the white film surface on the cut surface. The transparent particles are completely submerged in the binder coating film provided on the surface, and the exposure rate of 50% is the transparent particles in the binder coating film provided on the white film surface at the cut surface. Is half filled and the other half protrudes out of the coating.
To define the exposure rate more precisely, the exposure rate is calculated by drawing a straight line passing through the center of the cross section of the transparent particle in the cut surface of the slice sample and perpendicular to the coating surface of the film. Of the two points that intersect the surface of the transparent particles in the plane, S is the point on the exposed surface, T is the point on the unexposed surface, and the straight line is the coating surface of the binder. When the intersecting point is B, it is expressed by (distance between S and B) / (distance between S and T).
That is, the exposure rate (%) is defined by the following formula.
Exposure rate
= (Distance between S and B) / (distance between S and T) × 100 (%)
The center of the cross section of the transparent particle in the cut surface is the center of the circle of the cross section when the particle is spherical, and the center of gravity of the cross section when the particle is non-spherical.
As the transparent particles, both inorganic transparent particles and organic transparent particles can be used. These may use a plurality of particles together. The transparent particles preferably have a light transmittance of 50% or more, preferably 60% or more, and more preferably 70% or more, and preferably have no light absorption in the visible region.
As the organic transparent particles, for example, acrylic particles, silicone particles, and styrene particles can be used. Acrylic particles and styrene particles are preferred because they hardly absorb light in the visible light region. As the inorganic transparent particles, for example, glass particles can be used.
The transparent particles that form the transparent protrusions may be supported on the white film so that the particles do not overlap in the normal direction of the film, and are supported so that many transparent particles overlap in the normal direction of the white film. May be. In the latter case, 2 to 30 transparent particles having a particle diameter of 5 to 100 μm may be included in a direction perpendicular to the film surface between the surface of the white film and the surface of the transparent particle layer. In this case, the transparent particle layer is supported on the white film by the transparent particles being bonded to each other by the binder.
In this case, the height of the transparent protrusion is determined by specifying the vertex of the transparent particle positioned on the outermost surface of the transparent particle layer and the reference surface of the binder supporting the transparent particle layer, and measuring the height of the vertex from the reference surface. Is required. In this case, the reference surface of the binder is a surface obtained by averaging the surface of the binder covering other transparent particles that support the transparent particles on the outermost surface from the lower side (that is, the side close to the white film).
binder
As the binder in the coating film of the binder that supports the transparent particles on the surface of the white film, an acrylic resin, a polyester resin, a polyurethane resin, a polyesteramide resin, a polyolefin resin, a copolymer or a blend thereof can be used. In addition to the binder described above, the binder may be crosslinked by blending an isocyanate, melamine, or epoxy crosslinking agent.
When the coating film of the binder does not contain a phosphor, the amount of the binder with respect to 100 parts by weight of the transparent particles is, for example, 5 to 200 parts by weight, preferably 10 to 100 parts by weight, and more preferably 10 to 70 parts by weight. By setting the ratio in this range, it is possible to obtain a light collecting effect by the transparent particles without dropping the particles. In addition, although a commercially available binder is sold in a mode in which a binder solid content such as an acrylic resin is dissolved in a solvent, the amount of the binder of the coating film in the present invention is the amount of the binder solid content in the coating film after drying. .
The coating film of the binder preferably contains a phosphor. That is, in the present invention, the transparent particles are preferably supported on the white film by a coating film of a binder composition containing a binder and a phosphor. When the phosphor composition is contained in the binder composition, the ratio of the transparent particles supported on the film surface and the binder composition of the coating film is used to obtain a film without dropping particles while effectively improving the luminance. The binder composition is preferably 70 to 30 parts by weight with respect to 30 to 70 parts by weight of the transparent particles. In addition, a binder composition is the weight of the solid part except a solvent.
When the binder composition contains a phosphor, the phosphor content is such that the reflection film chromaticity in the XYZ color system measured with a C light source is x = 0.290 to 0.330, y = 0.300 to A range of 0.340 is preferable. For this reason, the phosphor content in the binder composition is preferably 1 to 20%, 5 to 20% by weight, and more preferably 10 to 20% by weight, based on the weight of the binder composition. If it is less than 1% by weight, the effect of obtaining a high reflectance cannot be obtained. If it exceeds 20% by weight, the film is highly colored by the phosphor, and color shift occurs when used as a reflector of a liquid crystal display device.
Phosphor
When a coating film is formed with a binder composition containing a phosphor, a phosphor that is excited by light having a wavelength of 400 to 450 nm and emits light having a wavelength of 500 to 600 nm is used as the phosphor. This means that the excitation wavelength of the phosphor in the present invention is in the band of 400 to 450 nm and the emission wavelength is in the range of 500 to 600 nm, but the excitation wavelength is not in this range or the emission wavelength is in this range. Otherwise, it is not possible to obtain a reflective film that is not colored and has a high reflectance. When the excitation wavelength is not in the region of 400 to 450 nm, but only in the region of less than 400 nm, high reflectance cannot be obtained when used as a reflector, and coloring in the region exceeding 450 nm results from absorption of visible light. And a white reflective film cannot be obtained. When the emission wavelength is not in the region of 500 to 600 nm, but in the region of less than 500 nm or more than 600 nm, the effect of improving the reflectivity cannot be obtained when used as a reflector of a liquid crystal display device, and the luminance is improved by the phosphor. The effect cannot be obtained.
The phosphor in the present invention may be an inorganic phosphor made of an inorganic substance or an organic phosphor made of an organic substance. The phosphor in the present invention needs to emit stable fluorescence over a long period of time, and must not be altered or decomposed by ultraviolet rays. If the phosphor is altered or decomposed, the film will turn yellow, and accurate color reproduction will not be possible when used as a reflector of a liquid crystal display device. Further, when the phosphor is altered or decomposed, the phosphor does not emit light, and the luminance due to the phosphor decreases when used as a reflector of a liquid crystal display device. For this reason, as the phosphor in the present invention, an inorganic phosphor that is less susceptible to alteration and decomposition than an organic phosphor and is stable is preferable.
Examples of inorganic phosphors that satisfy the requirements for the excitation wavelength and emission wavelength include alkaline earth metal sulfides having a rock salt crystal structure, such as zinc sulfide (ZnS), strontium sulfide (SrS), and yttrium oxide (Y ₂ O ₂ ) As a base, and a phosphor containing europium (Eu) or copper (Cu) as an activator can be used. Barium-magnesium-aluminum composite oxide (Ba ₃ MgAl ₁₀ O ₁₇ ) As a matrix and a phosphor containing europium (Eu) or manganese (Mn) as an activator can be used. In addition, lanthanum phosphate (LaPO ₄ ) And a phosphor containing Ce and Tb as activators.
Commercially available inorganic phosphors include, for example, green light emitting inorganic phosphor 2210 (made by Kasei Optronics, using ZnS as a base material and Cu as an activator), red inorganic phosphor D1110 (manufactured by Nemoto Special Chemical Co., Ltd.), Y ₂ O ₃ As a matrix, Eu as an activator), blue inorganic phosphor D1230 (manufactured by Nemoto Special Chemical Co., Ltd., SrS as a matrix, Eu as an activator), green inorganic phosphor KX732A (made by Kasei Optronics, Barium / magnesium / aluminum composite oxide (Ba ₃ MgAl ₁₀ O ₁₇ ) As a base material and Eu and Mn as activators).
Examples of organic phosphors that satisfy the requirements for the excitation wavelength and emission wavelength include stilbene fluorescent agents, distilbene fluorescent agents, benzoxazole fluorescent agents, styryl / oxazole fluorescent agents, and pyrene / oxazole fluorescent agents. , A coumarin fluorescent agent, an imidazole fluorescent agent, a benzimidazole fluorescent agent, a pyrazoline fluorescent agent, an aminocoumarin fluorescent agent, a distyryl-biphenyl fluorescent agent, and a naphthalimide fluorescent agent. Among these, benzoxazole-based fluorescent agents, styryl-oxazole-based fluorescent agents, and naphthalimide-based fluorescent agents are preferred because of their high durability and high effect of improving reflectance. Specifically, yeast bright OB- 1 (benzoxazole-based fluorescent agent manufactured by Eastman), Uvitex-OB (styryl-oxazole-based fluorescent agent manufactured by Ciba Geigy), and Lumogen Green 850 (naphthalimide-based fluorescent agent manufactured by BASF) are preferably used.
Light reflectance and chromaticity
The light reflectance of the reflective film for an illuminating device of the present invention is preferably 96% or more for light having a wavelength of 550 nm, whether or not the binder composition of the coating film contains a phosphor. A high luminance can be obtained when the reflectance is 96% or more.
When the reflective film for an illumination device of the present invention contains a phosphor in the binder composition of the coating film, the chromaticity in the XYZ color system measured with a C light source is x = 0.290 to 0.330, y = It is preferably 0.300 to 0.340. When the chromaticity is within this range, it is possible to obtain a reflector for an illuminating device, particularly a reflector for a liquid crystal display, which contains a phosphor and is excellent in color reproducibility.
UV absorber
The binder composition of the coating film preferably contains an ultraviolet absorber in order to prevent deterioration due to ultraviolet rays. As the ultraviolet absorber in the present invention, a substance having ultraviolet absorbing ability is used. This may be an organic compound or an inorganic compound. In the case of an organic compound, for example, a benzophenone UV absorber, a benzotriazole UV absorber, a triazine UV absorber, a cyanoacrylate UV absorber, a salicylic acid UV absorber, a benzoate UV absorbers and oxalic anilide UV absorbers can be used. In the case of an inorganic compound, for example, a silylated modified product such as an alkoxy carbamyl adduct of alkoxysilyl or alkanoylsilyl, an epoxy of a hydroxyl group and an epoxy group-containing silane compound of an aromatic ultraviolet absorber such as 2,4-dihydroxybenzophenone A silylation-modified ultraviolet absorber obtained by reacting with a group can be used.
In the case where the binder composition of the coating film contains an ultraviolet absorber, the content may be an amount that can prevent the deterioration of the organic phosphor, and an ultraviolet absorber contained in an amount necessary for this purpose. It only has to be. This amount is preferably 1 to 15% by weight, more preferably 2 to 5% by weight, based on the weight of the binder composition, when the ultraviolet absorber is of a low molecular type. By containing in this range, it is possible to effectively prevent the organic phosphor from being deteriorated by ultraviolet rays and to obtain a coating film without coloring.
As the ultraviolet absorber, a polymer type may be used. In this case, for example, a copolymer obtained by copolymerizing a monomer component having a substituent having ultraviolet absorbing ability with another monomer component can be used. As this copolymer, for example, a polymer obtained by copolymerization of a benzotriazole-based reactive monomer and an acrylic monomer can be preferably used.
When the ultraviolet absorber is of a high molecular type, the copolymerization amount of the monomer having a substituent having an ultraviolet absorptivity is preferably 10% by weight based on the total amount of all monomers constituting the copolymer. Above, more preferably 20% by weight or more, particularly preferably 35% by weight or more. Of course, it may be a homopolymer of a monomer having a substituent having ultraviolet absorbing ability. If it is less than 10% by weight, the organic phosphor cannot be prevented from being deteriorated by ultraviolet rays. From the viewpoint of obtaining a tough coating film, the molecular weight of the copolymer is preferably 5000 or more, more preferably 10,000 or more, and particularly preferably 20000 or more. These copolymerized polymers can be used as a coating solution in a state dissolved or dispersed in an organic solvent or water. In addition to these, commercially available hybrid ultraviolet absorbing polymers such as U-double (manufactured by Nippon Shokubai Co., Ltd.) can be used as the ultraviolet absorber.
Light stabilizer
In addition to the ultraviolet absorber, it is preferable to use a light stabilizer in combination with the binder composition of the coating film from the viewpoint of obtaining excellent durability. In this case, the blending amount of the light stabilizer is, for example, 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the weight of the binder composition.
As the light stabilizer, a hindered amine light stabilizer is preferable. Specifically, for example, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl succinate · 1- (2-hydroxyethyl) ) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate can be used.

Hereinafter, the present invention will be described in detail by way of examples. Measurement and evaluation were performed by the following methods.
(1) Relative brightness
The brightness of the display device when used as a reflector in a liquid crystal display device was evaluated. Remove the reflective film of the backlight of the 32-inch television (BRAVIA KDL-32V2500) manufactured by Sony Corporation, install the film to be evaluated, and use a luminance meter (Model MC-940, manufactured by Otsuka Electronics) The luminance was measured at a measurement distance of 500 mm from the center in front. The relative luminance was calculated by the following formula.
Relative brightness
== (Brightness of film to be evaluated) / (Brightness of reference film) × 100 (%)
The film used as the reference film differs depending on the table on which the evaluation results are described. The following films were used as reference films.
Table 1: Film of Comparative Example 1-1 having no transparent protrusions.
Table 2: Film of Comparative Example 2-1 without projections made of transparent particles.
Table 3: Film of Comparative Example 3-1, which is not provided with protrusions made of transparent particles.
Table 4: Film of Reference Example 1-1 in which the binder of the coating film does not contain a phosphor.
Table 5: Film of Comparative Example 5-1, which is not provided with protrusions made of transparent particles.
(2) Transparent protrusion
(2-1) Film coverage by transparent protrusions
A sample was cut out using a microtome so that the thickness direction of the film was a cut surface. This slice sample was observed at a magnification of 3000 times using a Hitachi S-4700 field emission scanning electron microscope. The measurement area of the total length of 6 mm of the measurement area of 3 mm length in each of the two orthogonal directions in the film plane is observed, and the lengths of the portions not covered with the transparent protrusions in the measurement area are integrated. Obtained by the formula.
Coverage
== (6 mm- (integrated length of the portion not covered with the transparent protrusion (mm)))
/ 6mm x 100 (%)
(2-2) Transparent protrusion height
Using the film surface as a reference surface, the heights of the vertices of 20 arbitrary transparent protrusions were measured, and the average value of these was taken as the height of the transparent protrusions. In addition, when the transparent protrusion was formed with transparent particles and the transparent particles were buried in the binder, the surface of the binder was used as the reference surface. The height was measured by cutting a section sample from the film using a microtome, and observing and photographing the sample at 300 times using an optical microscope.
(3) Transparent particles that form protrusions
(3-1) Average particle size of transparent particles
Using an S-4700 field emission scanning electron microscope manufactured by Hitachi, Ltd., an average particle size was determined by arbitrarily measuring 100 particles (raw material) before being added to the resin at a magnification of 1000 times. When the particles were not spherical, (major axis + minor axis) / 2 was defined as the average particle size.
(3-2) Aspect ratio of transparent particles
Using an S-4700 field emission scanning electron microscope manufactured by Hitachi, Ltd., 30 exposed particles were arbitrarily observed at a magnification of 500 times, and the average value was calculated from the values of the major axis and minor axis according to the following formula.
Aspect ratio = major axis / minor axis
(3-3) D50 of transparent particles
Using a particle size distribution meter (LA-950, manufactured by Horiba, Ltd.), the particle size distribution of the transparent particles of the raw material was obtained, and the particle size at which the passing percentage was 50% by weight was defined as D50.
(3-4) D10 / D90 of transparent particles
Using a particle size distribution meter (LA-950, manufactured by HORIBA, Ltd.), the particle size distribution of the transparent particles of the raw material is obtained, and the particle diameter at which the passing percentage is 10 wt% is D10, and the passing percentage is 90 wt%. The particle diameter was set to D90, and D10 / D90 was calculated.
(4) Average particle size of inorganic and organic particles of white film
The average particle size of the inorganic and organic particles of the white film was determined by obtaining the particle size distribution of the raw material particles with a particle size distribution meter (LA-950, manufactured by HORIBA, Ltd.), and the particle size at d50 was defined as the average particle size.
(5) Coating thickness
The cross section of the film sample was observed and photographed with a digital microscope (HIROX Co. Ltd., HI-SCOPE Advanced KH-3000) at a magnification of 5 times, the thickness of the binder was judged from the photograph, and 10 points were arbitrarily measured. Their average value was determined.
(6) Film thickness
(6-1) Film thickness
The film sample was measured for 10-point thickness using an electric micrometer (K-402B, manufactured by Anritsu), and the average value was defined as the film thickness.
(6-2) Thickness of each layer of film
The sample was cut into a triangle, fixed in an embedding capsule, and then embedded in an epoxy resin. And after making the cross section parallel to a vertical direction into a thin film section with a microtome (ULTRACUT-S), the embedded sample was observed and photographed using an optical microscope, and the thickness ratio of each layer was measured from the photograph, and the entire film The thickness of each layer was determined by calculating from the thickness.
(7) Exposure rate of transparent particles
Section sample 1 and section sample 2 were cut out from the film using a microtome. The section sample 1 is a section sample cut so that one direction randomly selected in the film plane and the thickness direction of the film are cut surfaces, and the section sample 2 is a random sample selected in the section sample 1. It is the section | slice sample cut out so that the direction orthogonal to a direction and the thickness direction may become a cut surface.
S-4700 manufactured by Hitachi, Ltd., for a measurement area of 6 mm in total including an area of 3 mm in the length of the coating film surface of the binder of the section sample 1 and an area of 3 mm in length of the coating film surface of the binder of the section sample 2 Observation was performed at a magnification of 3000 times using a field emission scanning electron microscope.
As for the exposure rate, when a straight line passing through the center of the cross section of the transparent particle in the cut surface of the slice sample and perpendicular to the coating surface of the film is drawn, this straight line intersects the surface of the transparent particle in the cut surface of the film slice. Of the two points, S is the point on the exposed surface, T is the point on the unexposed surface, and B is the point where the straight line intersects the coating surface of the binder. (Distance between S and B) / (Distance between S and T)
That is, the exposure rate (%) is defined by the following formula.
Exposure rate
== (Distance between S and B) / (Distance between S and T) × 100 (%)
The center of the cross section of the transparent particle in the cut surface is the center of the circle of the cross section when the particle is spherical, and the center of gravity of the cross section when the particle is non-spherical.
(8) Film surface coverage with transparent particles
Evaluation was made on the section samples 1 and 2 obtained in (7) above.
S-4700 manufactured by Hitachi, Ltd., for a measurement area of 6 mm in total including an area of 3 mm in the length of the coating film surface of the binder of the section sample 1 and an area of 3 mm in length of the coating film surface of the binder of the section sample 2 Observation was performed at a magnification of 3000 times using a field emission scanning electron microscope.
The coverage was calculated by the following formula by integrating the lengths of the film surface portions not covered with the transparent particles in the measurement region within the cut surface of the section sample (see FIG. 1).
Coverage
= (6 mm- (integrated length of the portion not covered with transparent particles (mm)))
/ 6mm x 100 (%)
(9) Stretchability
Whether the film could be stably formed when stretched 2.5 to 3.4 times in the vertical direction and 3.5 to 3.7 times in the horizontal direction to form a film was evaluated and evaluated according to the following criteria.
○: Stable film formation for 1 hour or more
×: Cutting occurs within 1 hour, and stable film formation is not possible
(10) Yellowing over time
The film sample was irradiated with a high-pressure mercury lamp (“Toscure 401” manufactured by Harrison Toshiba Lighting, with a glass filter), and the color change of the sample was evaluated. The irradiation time in this evaluation was 50 hours, and the color change before and after the irradiation was evaluated. Irradiance by irradiation is 18mW / cm²Met. In addition, when the structure of the film provided the reflective layer on one side of the support layer, measurement was performed from the reflective layer side.
Initial film hue (L₁ ^*, A₁ ^*, B₁ ^*) And film color after irradiation (L₂ ^*, A₂ ^*, B₂ ^*) Were measured with a color difference meter (Nippon Denshoku Industries SZS-Σ90 COLOR MEASURING SYSTEM), and a hue change dE * represented by the following formula was calculated and evaluated according to the following criteria.
DE^*
= {(L₁ ^*-L₂ ^*)²+ (A₁ ^*-A₂ ^*)²+ (B₁ ^*-B₂ ^*)²}^1/2
◎: dE^*≤ 5
○: 5 <dE^*≦ 10
△: 10 <dE^*≦ 15
X: 15 <dE^*
(11) Existence of excitation light emission by light of 400 to 450 nm and emission peak wavelength
Fluorescence spectrum was measured by making light incident on the surface coated with the phosphor. Measurement is performed using a fluorescence spectrophotometer F-4500 (manufactured by Hitachi) in the region of excitation wavelength of 400 to 450 nm and emission wavelength of 380 to 780 nm, and the presence or absence of fluorescence emission due to excitation is observed. The emission peak wavelength was determined from the spectrum.
(12) Presence or absence of particles falling
An acrylic plate having a right side with a thickness of 2 mm and a width of 20 mm was pressed vertically against the reflective surface of the film sample with a load of 300 g, and the distance of 30 mm was reciprocated 10 times. The adhesion state of the powder to the acrylic board at this time was confirmed visually and evaluated according to the following criteria.
○: Almost no generation of powder can be confirmed.
X: Generation of powder can be confirmed.
(13) Luminance improvement rate and luminance maintenance rate
(13-1) Brightness improvement rate as a reflector
Measured and evaluated by incorporating a film into the backlight. The backlight used was a direct type backlight (diagonal 20 inches) unit used for a liquid crystal television set (AQUAS-20V manufactured by SHARP) prepared for evaluation. Instead of the light reflection sheet originally incorporated, A film to be measured was incorporated. The measurement was performed by dividing the backlight surface into 4 × 2 × 2 sections and determining the front luminance after 1 hour of lighting.
Luminance was measured using BM-7 manufactured by Topcon Corporation. The measurement angle is 1 °, and the distance between the luminance meter and the backlight is 50 cm. The backlight surface was divided into four parts, a straight line passing through the center of the backlight surface and parallel to the width direction of the backlight surface, and a straight line passing through the center of the backlight surface and parallel to the vertical direction of the backlight surface. The center of each region was taken as the measurement point.
The luminance at each of the four measurement points was measured, and a simple average was obtained to obtain the average luminance. The luminance improvement rate was calculated by the following formula using the average luminance obtained with the film before and after the application of the fluorescent material.
Brightness improvement rate
= (Average luminance after fluorescent material coating) / (Average luminance before fluorescent material coating) x 100 (%)
(13-2) Luminance maintenance rate by durability test
A durability test was performed for 3000 hours with the above backlight turned on with the film to be evaluated incorporated. The luminance maintenance rate was calculated by the following formula.
Luminance maintenance rate
= (Average brightness after durability test) / (Luminance before durability test) x 100 (%)
(14) Chromaticity
(14-1) Chromaticity difference as a reflector
Measured and evaluated by incorporating a film into the backlight. The backlight used was a direct type backlight (diagonal 20 inches) unit used for a liquid crystal television set (AQUAS-20V manufactured by SHARP) prepared for evaluation. Instead of the light reflection sheet originally incorporated, A film to be measured was incorporated. The measurement was performed by dividing the backlight surface into 4 × 2 × 2 sections and determining the front luminance after 1 hour of lighting.
The chromaticity was measured using Topcon BM-7. The measurement angle is 1 °, and the distance between the luminance meter and the backlight is 50 cm. The backlight surface was divided into four parts, a straight line passing through the center of the backlight surface and parallel to the width direction of the backlight surface, and a straight line passing through the center of the backlight surface and parallel to the vertical direction of the backlight surface. The center of each region was taken as the measurement point.
Measure chromaticity (x, y) at four measurement points, and calculate a simple average to obtain average chromaticity (x, y). The distance between the average chromaticity (x, y) and the reference color (x = 0.300, y = 0.310) was calculated to calculate the chromaticity difference Δxy.
Δx = reference coordinate (x = 0.300) −measurement coordinate (x)
Δy = reference coordinate (y = 0.310) −measurement coordinate (y)
Δxy = (Δx²+ Δy²)^1/2
The calculated Δxy was evaluated according to the following criteria.
◎ :: Δxy <0.005
○: 0.005 ≦ Δxy <0.010
×: 0.010 ≦ Δxy
(14-2) Chromaticity difference by durability test
A durability test was performed for 3000 hours with the above backlight turned on with the film to be evaluated incorporated. The distance between the average chromaticity (x, y) before the durability test and the average chromaticity (x, y) after the durability test was calculated and evaluated by the following formula.
Δx = coordinates before durability test (x)-coordinates after durability test (x)
Δy = coordinates before durability test (y)-coordinates after durability test (y)
Δxy = (Δx²+ Δy²)^1/2
The calculated Δxy was evaluated according to the following criteria.
◎ :: Δxy <0.005
○: 0.005 ≦ Δxy <0.010
×: 0.010 ≦ Δxy
(14-3) Chromaticity by C light source
Measured using a C light source with a color difference meter (SZS-Σ90 COLOR MEASURING SYSTEM manufactured by Nippon Denshoku).
(15) Light reflectance
An integrating sphere was attached to a spectrophotometer (Shimadzu UV-3101PC), and BaSO₄The light reflectance when the white plate was 100% was measured at a wavelength of 550 nm.
(16) Coating film components and white film
The components of the coating film are as follows. In the table, “wt%” may be expressed as “wt%”.
<Transparent particles / protrusions>
MBX-50SS:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 50 μm
MBX-30SS:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 30 μm
MBX-20SS:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 20 μm
MBX-15SS:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 15 μm
MBX-12SS:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 12 μm
MBX-10SS:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 10 μm
MBX-50:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 50 μm
MBX-30:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 30 μm
MBX-20:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 20 μm
MBX-15:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 15 μm
MBX-12:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 12 μm
MBX-8:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 8 μm
MBX-5:
Made by Sekisui Plastics Co., Ltd. Transparent acrylic particles with an average particle size of 5 μm
J-120:
Transparent glass particles with an average particle size of 105 μm manufactured by Potters-Ballottini
MX-1000:
Made by Soken Chemical Co., Ltd. Transparent acrylic particles with an average particle size of 10 μm
MX-150:
Made by Soken Chemical Co., Ltd. Transparent acrylic particles with an average particle size of 2 μm
MR-20G:
Made by Soken Chemical Co., Ltd. Transparent cross-linked acrylic particles with an average particle size of 20 μm
MR-10G:
Made by Soken Chemical Co., Ltd. Transparent cross-linked acrylic particles with an average particle size of 10 μm
<Binder>
S2740: Nihon Shokubai Co., Ltd. U-Double S2740
Acrylic binder consisting of 50 wt% solid acrylic resin and 50 wt% volatile organic solvent
A807BA: DIC Corporation Acridic A807BA
Acrylic binder consisting of 50 wt% solid acrylic resin and 50 wt% volatile organic solvent
<Crosslinking agent>
HL: Nippon Polyurethane Industry Coronate HL
Crosslinking agent consisting of 75% by weight of solid content crosslinking agent and 25% by weight of volatile organic solvent
<Phosphor>
OB-1: East Bright OB-1 manufactured by Eastman
Green 850: BASF Rumogen Green 850
Uvitex-OB: Uvitex-OB manufactured by Ciba Geigy
<Solvent>
MEK: Methyl ethyl ketone
Unless otherwise specified in the Examples and Comparative Examples, the total film composed of a total of two layers, a white film, a reflective layer made of a polyester composition containing barium sulfate particles as a void forming agent, and a support layer made of polyester. A white film with a thickness of 225 μm (Teijin Tetron UX02-225, manufactured by Teijin DuPont Films, reflectivity of reflection layer: 98.5%) was used.
Example 1-1
On the reflective layer of the white film, a coating solution having the composition shown in the following preparation recipe is applied with a die coating apparatus to a wet thickness of 20 g / m.²After coating with the coating amount, a reflective film was obtained by drying in an oven.
Preparation recipe 1-1)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-20SS (38% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (20% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Example 1-2
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 10 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-2)
-Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-10SS (30% by weight)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (28% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
・ Organic solvent: ethyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Example 1-3
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 25 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-3)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-30SS (32% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
・ Organic solvent: methyl ethyl ketone (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Example 1-4
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 30 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-4)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-50SS (25% by weight)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (38% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: ethyl acetate (34% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Example 1-5
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 15 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-5)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-15SS (19% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (37% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (4% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Example 1-6
A quadrangular pyramid-shaped protrusion was formed on the entire surface of the white film with no gap. That is, a coating liquid having the composition shown in the following preparation recipe is poured into a SUS mold so as to form a quadrangular pyramid, and a white film is adhered to the SUS mold, and UV is applied with a high-pressure mercury lamp (Toscurer manufactured by Harrison Toshiba Lighting). The coating liquid was cured by irradiating light and dried in an oven at 100 ° C. to form a quadrangular pyramid on the entire reflective surface of the white film to obtain a reflective film. The size of the reflective film was adjusted to the size of the reflective film of the backlight of 32-inch television (BRAVIA KDL-32V2500) manufactured by Sony Corporation used for evaluation of relative luminance. FIG. 1 shows a schematic diagram of the square thrust portion of the mold used for forming the square thrust projection.
Preparation recipe 1-6) UV curable resin
・ Daicel UC EB3700
(Bisphenol A type epoxy acrylate) (25% by weight)
・ Shin Nakamura Chemical Co., Ltd. BPE200
(Ethylene oxide-added bisphenol A methacrylic ester) (8% by weight)
・ Daiichi Pharmaceutical Co., Ltd. BR-31
(Tribromophenoxyethyl acrylate) (42% by weight)
・ Toa Gosei Co., Ltd. M-110
((Meth) acrylate of p-cumylphenol reacted with ethylene oxide
E)) Service (8% by weight)
LR8883 (radical generator) manufactured by BASF (1% by weight)
-Methyl ethyl ketone (16% by weight)
Evaluation results are shown in Table 1-3.
Example 1-7
On a white film, a wet coating amount of 15 g / m is applied to the coating solution having the composition of the preparation recipe 6 in Example 1-6 using a die coating apparatus.²After coating at the coating amount, a high-pressure mercury lamp (Toscurer manufactured by Harrison Toshiba Lighting) with the coating layer formed with irregularities on the coated surface using the nip roller provided with prismatic irregularities as shown in FIG. Curing was performed by irradiating with UV light and drying in an oven at 100 ° C. to prepare a prism shape.
In the measurement of relative luminance in this example, a reflective film was installed so that the flow direction of the prism was parallel to the cold cathode tube of the light source of the backlight.
Evaluation results are shown in Table 1-3.
Example 1-8
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 15 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-8)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-20SS (38% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (20% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
-Phosphor: Eastman East Bright OB-1 (3.4% by weight)
・ Organic solvent: butyl acetate (36.6% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Example 1-9
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 15 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-9)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-20SS (38% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (20% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
-Phosphor: BASF Rumogen Green 850 (2.3% by weight)
・ Organic solvent: butyl acetate (37.7% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Example 1-10
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 15 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-10)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-20SS (38% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (20% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
-Phosphor: Ciba Geigy Uvitex-OB (2.3 wt%)
・ Organic solvent: butyl acetate (37.7% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Comparative Example 1-1
The film was evaluated without applying the coating solution on the white film. The evaluation results are shown in Table 1-3.
Comparative Example 1-2
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and wet thickness 40 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-7)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (57 wt%)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Comparative Example 1-3
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 2 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-8)
Protrusion forming material: Soken Chemical Co., Ltd. MX-150 (30% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (27% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Comparative Example 1-4
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, wet thickness 80g / m²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-8)
Protrusion forming material: Potters-Ballottini J-120
,,,,,,,,,,,,,, And,,,,,,,,,, 2015, 2015, 2015 will be: ······························· 50% (30% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (27% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
・ Organic solvent: Butyl acetate, Inc. (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Comparative Example 1-5
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and wet thickness 40 g / m.²A reflective film was obtained in the same manner as in Example 1-1, except that the coating amount was as follows.
Preparation recipe 1-9)
Protrusion forming material: Sekisui Plastics Co., Ltd. MBX-50 (3% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (50% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (44% by weight)
The composition of the obtained reflective film coating film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.
Comparative Example 1-6
A reflective film provided with a prism in the reflective layer was obtained in the same manner as in Example 1-6, except that the shape of the prism provided on the reflective layer of the white film was changed to the shape shown in FIG. The evaluation results are shown in Table 1-3.
Comparative Example 1-7
A film was obtained by processing the surface in the same manner as in Example 1-7 except that the shape of the prism provided on the reflective layer of the white film was changed to the shape shown in FIG. The evaluation results are shown in Table 1-3.

Example 2-1
On the reflective layer of the white film, a coating solution having the composition shown in the following preparation recipe is applied with a die coating apparatus to a wet thickness of 25 g / m.²After coating with the coating amount, a reflective film was obtained by drying in an oven.
Preparation recipe 2-1)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-30SS (35% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (23% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Example 2-2
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 12 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-2)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15SS (35% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (23% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Example 2-3
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and wet thickness 40 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-3)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-50SS (32% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Example 2-4
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 10 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-4)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-12SS (38% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: ethyl acetate (34% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Example 2-5
Change the coating liquid to a coating liquid with the composition shown in the following preparation recipe, wet thickness 7g / m²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-5)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-10SS (19% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (37% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (4% by weight)
・ Organic solvent: ethyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Example 2-6
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 8 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-6)
-Transparent particles: Soken Chemical Co., Ltd. MX-1000 (40% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
・ Organic solvent: methyl ethyl ketone (33% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Comparative Example 2-1
The film was evaluated without applying the coating solution on the white film. The evaluation results are shown in Table 2-3.
Comparative Example 2-2
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and wet thickness 40 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-7)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (57 wt%)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Comparative Example 2-3
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 2 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-8)
-Particles: Soken Chemical Co., Ltd. MX-150 (30% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (27% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Comparative Example 2-4
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, wet thickness 80g / m²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-9)
・ Particles: Potters-Ballottini J-120
,,,,,,,,,,,,,, And,,,,,,,,,, 2015, 2015, 2015 will be: ······························· 50% (30% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (27% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Comparative Example 2-5
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and wet thickness 40 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-10)
・ Particle: Sekisui Plastics Co., Ltd. MBX-50 (3% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (50% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (44% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.
Comparative Example 2-6
Change the coating liquid to a coating liquid having the composition shown in the following preparation recipe, and a wet thickness of 8 g / m.²A reflective film was obtained in the same manner as in Example 2-1, except that the coating amount was applied in the same manner as in Example 2-1.
Preparation recipe 2-11)
・ Particle: Sekisui Plastics Co., Ltd. MBX-8 (1% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (56% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Example 3-1
132 parts by weight of dimethyl terephthalate, 18 parts by weight of dimethyl isophthalate (12 mol% based on the total dicarboxylic acid component of the polyester), 98 parts by weight of ethylene glycol, 1.0 part by weight of diethylene glycol, 0.05 part by weight of manganese acetate, acetic acid 0.012 parts by weight of lithium was charged into a rectification column and a flask equipped with a distillation condenser, and heated to 150 to 235 ° C. with stirring to distill methanol to conduct a transesterification reaction. After the methanol was distilled off, 0.03 part by weight of trimethyl phosphate and 0.04 part by weight of germanium dioxide were added, and the reaction product was transferred to the reactor. Next, while stirring, the pressure in the reactor was gradually reduced to 0.5 mmHg and the temperature was raised to 290 ° C. to carry out a polycondensation reaction to obtain polyester. Barium sulfate particles having an average particle diameter of 1.2 μm were added to this polyester to obtain a polyester composition for a support layer containing 4% by weight of barium sulfate particles. Barium sulfate particles having an average particle diameter of 1.2 μm and phosphors are added to the same polyester, and 47% by weight of barium sulfate particles and 5.5% by weight of green light emitting inorganic phosphor KX732A (made by Kasei Optonix) are contained. A polyester composition for a white reflective layer was obtained.
Using these polyester compositions, each was supplied to two extruders heated to 270 ° C., and the polyester composition for the support layer and the polyester composition for the white reflective layer were combined into the reflective layer / support layer layer. The two-layer feed block device was used to form the structure, and the sheet was formed into a sheet from a die while maintaining the laminated state. Furthermore, the unstretched film obtained by cooling and solidifying the sheet with a cooling drum having a surface temperature of 25 ° C. is stretched 2.9 times in the longitudinal direction (longitudinal direction) in an atmosphere heated to 95 ° C., and cooled by a roll group at 25 ° C. did. Subsequently, while holding both ends of the longitudinally stretched film with clips, the film was stretched 3.6 times in a direction perpendicular to the longitudinal direction (lateral direction) in an atmosphere heated to 120 ° C. while being guided to a tenter. Thereafter, heat setting is carried out at a temperature of 215 ° C. in a tenter, and thereafter, 0.5% in the vertical direction and 2.0% in the horizontal direction are relaxed, cooled to room temperature, and a white base material that is a biaxially stretched laminated film A film was obtained. The white substrate film had a thickness of 225 μm, and the reflective layer had a reflectance of 98.7%.
After this, the coating liquid blended according to the following recipe in the barting apparatus is applied to the white reflective layer side at a wet coating amount of 25 g / m.²It was applied and then dried in an oven to obtain a reflective film. The particle size and aspect ratio of the transparent particles are summarized in Table 3-1.
Preparation recipe 3-1)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-30 (35% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (23% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate H (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3.
Example 3-2
A reflective film was obtained in the same manner as in Example 3-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe.
Preparation recipe 3-2)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15 (35% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (23% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3.
Example 3-3
A reflective film was obtained in the same manner as in Example 3-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe.
Preparation recipe 3-3)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-50 (32% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3.
Example 3-4
A reflective film was obtained in the same manner as in Example 3-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe.
Preparation recipe 3-4)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-12 (38% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: ethyl acetate (34% by weight)
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3.
Example 3-5
A reflective film was obtained in the same manner as in Example 3-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe.
Preparation recipe 3-5)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-5 (19% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (37% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (4% by weight)
・ Organic solvent: ethyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3.
Example 3-6
A reflective film was prepared in the same manner as in Example 3-2 except that the phosphor added to the white reflective layer of the white base film was changed to 2.5% by weight of the green light emitting inorganic phosphor 2210 (made by Kasei Optonix). Obtained.
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3.
Example 3-7
A reflective film was prepared in the same manner as in Example 3-2 except that the phosphor added to the white reflective layer of the white base film was changed to 0.1% by weight of organic fluorescent brightener OB-1 (Eastman). Obtained.
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3.
Comparative Example 3-1
A white base film was obtained in the same manner as in Example 3-1, except that no phosphor was added to the white reflective layer of the white base film, and the white base film was not coated with the coating liquid. Evaluated. The evaluation results are shown in Table 3-3.
Comparative Example 3-3
A reflective film is obtained in the same manner as in Example 3-2 except that no phosphor is added to the white reflective layer of the white base film and the coating liquid is changed to a coating liquid having the composition shown in the following preparation recipe. It was.
Preparation recipe 3-6)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15 (10% by weight)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (48% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3. Although the color shift due to coloring was small, the increase in luminance was small.
Comparative Example 3-4
A reflective film is obtained in the same manner as in Example 3-2 except that no phosphor is added to the white reflective layer of the white base film and the coating solution is changed to a coating solution having the composition shown in the following preparation recipe. It was.
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15 (2% by weight)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (56% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3. Although the color shift due to coloring was small, the increase in luminance was small.
Comparative Example 3-5
The white base film of Example 3-2 was evaluated without applying the coating liquid to the white base film. The evaluation results are shown in Table 3-3. Although the color shift due to coloring was small, the increase in luminance was small.
Comparative Example 3-6
The white base film of Example 3-6 was evaluated in a state where no coating liquid was applied to the white base film. The evaluation results are shown in Table 3-3. Although the color shift due to coloring was small, the increase in luminance was small.
Comparative Example 3-7
The white base film of Example 3-7 was evaluated without applying the coating liquid to the white base film. The evaluation results are shown in Table 3-3. Although the color shift due to coloring was small, the increase in luminance was small.
Comparative Example 3-8
A reflective film was obtained in the same manner as in Comparative Example 3-5 except that the amount of the green light emitting inorganic phosphor KX732A added to the reflective layer of the white base film was changed to 17% by weight. The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3. Although the increase in luminance was large, color misregistration due to coloring was large, making it difficult to use practically.
Comparative Example 3-9
A reflective film was obtained in the same manner as in Comparative Example 3-5 except that the amount of the green light emitting inorganic phosphor 2210 added to the reflective layer of the white base film was changed to 8% by weight. The composition of the obtained reflective film coating film is shown in Table 3-2 and the evaluation results are shown in Table 3-3. Although the increase in luminance was large, color misregistration due to coloring was large, making it difficult to use practically.

Example 4-1
On the reflective layer of the white film, with a die coating device, a coating solution having the composition shown in the following preparation recipe is applied so that the binder thickness after drying is 4 μm, and then dried in an oven. A reflective film was obtained.
Preparation recipe 4-1)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15SS (35% by weight)
・ Phosphor: Kasei Optonix KX-732A (10% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (23% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (30% by weight)
The composition of the obtained reflective film coating film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.
Example 4-2
A reflective film was obtained in the same manner as in Example 4-1, except that the coating liquid was changed to the coating liquid having the composition shown in the following preparation recipe and the binder thickness after drying was 8 μm.
Preparation recipe 4-2)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-50SS (32% by weight)
・ Phosphor: Kasei Optonix KX-732A (10% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (30% by weight)
The composition of the obtained reflective film coating film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.
Example 4-3
A reflective film was obtained in the same manner as in Example 4-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe and applied.
Preparation recipe 4-3)
-Transparent particles: Soken Chemical Co., Ltd. MX-1000 (40% by weight)
・ Phosphor: Kasei Optonics 2210 (5% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (25% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
・ Organic solvent: methyl ethyl ketone (28% by weight)
The composition of the obtained reflective film coating film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.
Reference example 4-1
A reflective film was obtained in the same manner as in Example 4-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe and applied.
Preparation recipe 4-4)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15SS (35% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (23% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (2% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.
Comparative Example 4-4
A reflective film was obtained in the same manner as in Example 4-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe and applied.
Preparation recipe 4-5)
・ Phosphor: Kasei Optonix KX-732A (10% by weight)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (57 wt%)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (30% by weight)
The composition of the obtained reflective film coating film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.
Comparative Example 4-5
A reflective film was obtained in the same manner as in Example 4-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following preparation recipe and applied.
Preparation recipe 4-6)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15SS (3% by weight)
・ Phosphor: Kasei Optonics 2210 (5% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (50% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (3% by weight)
Organic solvent: butyl acetate (39% by weight)
The composition of the obtained reflective film coating film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.
Comparative Example 4-6
The film was evaluated without applying the coating solution on the white film. The evaluation results are shown in Table 4-3.

Example 5-1
On the reflective layer of the white film, a coating solution having the composition shown in the following preparation recipe is applied with a die coating apparatus so that the binder thickness after drying is 8 μm, and then dried in an oven. A reflective film was obtained.
Preparation recipe 5-1)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-12 (35% by weight)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (21% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (4% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.
Example 5-2
A reflective film was obtained in the same manner as in Example 5-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following liquid preparation recipe and the binder thickness after drying was 10 μm.
Preparation recipe 5-2)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-15 (35% by weight)
-Acrylic binder: DIC Corporation Acridic A807BA (21% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (4% by weight)
・ Organic solvent: methyl ethyl ketone (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.
Example 5-3
A reflective film was obtained in the same manner as in Example 5-1, except that the coating liquid was changed to the coating liquid having the composition shown in the following preparation recipe and the coating was dried so that the binder thickness after drying was 14 μm.
Preparation recipe 5-3)
・ Transparent particles: Sekisui Plastics Co., Ltd. MBX-20 (35% by weight)
-Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (21% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (4% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.
Comparative Example 5-1
The film was evaluated without applying the coating solution on the white film. The evaluation results are shown in Table 5-3.
Comparative Example 5-3
A reflective film was obtained in the same manner as in Example 5-1, except that the coating liquid was changed to a coating liquid having the composition shown in the following liquid preparation recipe and the binder thickness after drying was 6 μm.
Preparation recipe 5-4)
・ Transparent particles: Soken Chemical Co., Ltd. MR-10G (15% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (37% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (8% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.
Comparative Example 5-5
A reflective film was obtained in the same manner as in Example 5-1, except that the coating solution was changed to a coating solution having the composition shown in the following preparation recipe and the coating was applied so that the binder thickness after drying was 14 μm.
Preparation recipe 5-5)
-Transparent particles: Soken Chemical Co., Ltd. MR-20G (15% by weight)
Acrylic binder: Nippon Shokubai Co., Ltd. Udouble S2740 (37% by weight)
・ Crosslinking agent: Nippon Polyurethane Industry Co., Ltd. Coronate HL (8% by weight)
Organic solvent: butyl acetate (40% by weight)
The composition of the obtained reflective film coating film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.

The reflective film for an illuminating device of the present invention can be used as a reflective plate for an illuminating device, and is also used as a reflective film for a backlight unit of a liquid crystal display device. It can be suitably used as a reflective film used in a backlight unit of a light-type liquid crystal display device.

Claims (8)

1. For a lighting device, comprising a white film and a transparent protrusion having a height of 3 to 50 μm provided on the surface of the white film, and the coverage by the transparent protrusion on the surface of the white film is 50 to 100% Reflective film.
2. The reflective film according to claim 1, wherein the transparent protrusions are made of transparent particles, and the transparent film having an exposure rate of 5 to 100% covers the surface of the white film with a coverage of 50 to 100% on the surface of the reflective film.
3. The reflective film according to claim 2, wherein the transparent particles are supported on the surface of the white film by a coating film of a binder.
4. The reflective film according to claim 2, wherein the average particle diameter of the transparent particles is 3 to 50 μm.
5. Claim 4 wherein the volume 50% particle diameter D50 of the transparent particles is 3 to 50 μm, and the ratio D10 / D90 of the volume 10% particle diameter D10 and the volume 90% particle diameter D90 of the transparent particles is 0.30 to 0.98. The reflective film as described.
6. The reflection according to claim 3, wherein the coating film of the binder comprises a binder composition containing a phosphor, and the phosphor content in the binder composition is 1 to 20% by weight based on the total weight of the binder composition. the film.
7. The reflective film according to claim 7, wherein the phosphor is an organic phosphor that is excited by light having a wavelength of 400 to 450 nm and emits light having a wavelength of 500 to 600 nm.
8. The reflecting film according to any one of claims 1 to 7, wherein the lighting device is a backlight unit of a liquid crystal display device.

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