KR20110044730A - Reflective film for illuminating device - Google Patents

Abstract

It consists of a white film and the transparent protrusion of the height of 3-50 micrometers formed in the surface of this white film, The coverage by the transparent protrusion of the white film surface is 50 to 100%, With the reflecting film for lighting devices characterized by the above-mentioned When used as a reflecting film in the backlight unit of a backlight liquid crystal display device, the reflective film for illuminating devices which can obtain a high brightness | luminance is provided.

Description

Reflective film for lighting device {REFLECTIVE FILM FOR ILLUMINATING DEVICE}

TECHNICAL FIELD The present invention relates to a reflective film used for a lighting device, and more particularly, to a reflective film for a lighting device used as a reflective film of a backlight unit of a liquid crystal display device.

The liquid crystal display device has a backlight method for placing a light source on the back of the backlight unit and a side light method for placing a light source on the side surface. In any of these systems, a reflective film is provided on the back of the backlight unit in order to prevent light from the light source from escaping to the back of the screen. Such a reflective film is required to have a thin and high reflectance.

Conventionally, a white film (Japanese Laid-Open Patent Publication No. 2004-050479, Japanese Laid-Open Patent Publication No. 2004-330727) in which a white pigment is added to polyester as such a reflective film, or a white film containing fine bubbles therein (Japanese Laid Open Patent) Japanese Patent Laid-Open No. Hei 6-322153 and Japanese Laid-Open Patent Publication No. Hei 7-118433) have been used.

In the backlight type liquid crystal display device, the improvement of the luminance can be achieved to some extent by improving the reflectance of the reflective film, but there is a limit only by the improvement of the reflectance.

In addition to improving the reflectance of the film itself, as a measure of improving the brightness, incorporating a fluorescent brightener into the reflective film has been studied, and coating of the fluorescent brightener on the surface of the reflective film has been proposed. Patent Publication No. 2002-40214). However, since a cold cathode tube is generally used as a light source for the backlight unit, when the fluorescent brightener is coated on the surface of the white film, the fluorescent brightener is deteriorated by ultraviolet rays emitted from the cold cathode tube, and the effect of improving the reflectance is It is lost over time. Even if it is intended to prevent the degradation of the fluorescent brightener by ultraviolet rays by the ultraviolet absorber, since the fluorescent brightener is originally excited by the ultraviolet rays and exhibits blue light emission, reflectance by the fluorescent brightener is improved by blending the ultraviolet absorber. Can not get the effect.

When the mirror surface reflection of a reflective film is strong, this inventor returns reflected light to the light source itself provided in front of a reflective film, ie, between a reflective film and a display surface among a backlight unit, and the light does not reach a display surface. In this case, attention was paid to the loss of light, which caused a decrease in luminance.

The present invention suppresses specular reflection by a reflecting film and gives a reflected light to reflect the directivity of avoiding the front light source, thereby obtaining high luminance when used as a reflecting film in a backlight unit of a backlight type liquid crystal display device. It is an object of the present invention to provide a reflective film for a lighting device.

A second object of the present invention is to provide a reflective film for an illuminating device excellent in workability while being able to obtain high luminance when used as a reflective film in a backlight unit of a backlight liquid crystal display device.

The third object of the present invention is a lighting device in which high luminance can be obtained when the backlight unit of a backlight liquid crystal display device is used as a reflective film, the color variation is small, and yellowing over time is suppressed. It is to provide the reflective film for.

That is, this invention consists of a white film and the transparent protrusion of 3-50 micrometers in height formed in the surface of this white film, The illumination rate characterized by the coverage of 50-100% by the transparent protrusion of the white film surface. It is a reflective film for devices.

This invention is an aspect in which a transparent processus | protrusion consists of transparent particle as a preferable aspect, and the transparent particle of 5-100% of exposure rate coat | covers the white film surface at 50-100% of coverage on the surface of a reflective film. Include. That is, this invention consists of a transparent film of 3-50 micrometers in height by the white film and the transparent particle which coat | covers the surface of this white film, The transparent particle of the exposure rate of 5 to 100% in the white film surface is The reflective film for illuminating devices which coat | covers the white film surface at 50 to 100% of coverage is included as a preferable aspect.

According to the present invention, it is possible to provide a reflecting film for a lighting device that can obtain high luminance when used as a reflecting film in a backlight unit of a backlight type liquid crystal display device.

Secondly, according to the present invention, a high brightness can be obtained when used as a reflecting film in a backlight unit of a backlight type liquid crystal display device, and it is possible to provide a reflecting film for a lighting device excellent in processability.

Thirdly, according to the present invention, when used as a reflective film in the backlight unit of the backlight type liquid crystal display device, a high luminance can be obtained, the color variation is small, and the yellowing device with time suppressed yellowing It is possible to provide a reflective film.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the square pyramid part of the metal mold | die used for square pyramidal processus formation in Example 1-6.
FIG. 2 is a prism-shaped concave-convex shape formed in the coating layer when forming the concave-convex in the coating layer using the nip roller in which the prism-shaped concave-convex concave-convex shape was formed in Example 1-7.
It is a schematic diagram of the square pyramid part of the metal mold | die used for the formation of a square pyramidal protrusion in Comparative Example 1-6.
4 is a prism-shaped concave-convex shape formed in the coating layer when forming the concave-convex in the coating layer by using a nip roller in which prism-shaped concavo-convex is formed 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 projection.
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 the transparent protrusion formed by the transparent particle | grains.
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 the transparent protrusion formed by the transparent particle | grains.

Carrying out the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

White film

The white film of this invention is a film which consists of a thermoplastic resin and made it white by containing a white coloring agent or a void formation material in a film.

As a thermoplastic resin which comprises a film, polyester, polyolefin, polystyrene is mentioned, for example, Polyester is preferable from a viewpoint of making mechanical property and thermal stability compatible.

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. As this dicarboxylic acid component, terephthalic acid, isophthalic acid, 2, 6- naphthalenedicarboxylic acid, 4,4'- diphenyl dicarboxylic acid, adipic acid, sebacic acid are mentioned, for example. As a diol component, ethylene glycol, 1, 4- butane diol, 1, 4- cyclohexane dimethanol, 1, 6- hexane diol is mentioned, for example.

Among these polyesters, aromatic polyesters are preferable, and polyethylene terephthalate is particularly preferable. The polyethylene terephthalate may be a homopolymer, but a copolymer polymer is preferable.

A white film may consist of a single layer and may consist of multiple layers. When a white film consists of multiple layers, it is preferable that it is a laminated film which consists of a white reflective layer which reflects light, and the support layer which supports this. In such a laminated film, the white reflective layer is a layer containing relatively many voids, and the support layer is preferably a layer containing relatively few voids or no voids. It is preferable that the polyester used for a white reflective layer is a copolyester, The ratio of a copolymerization component is 3-20 mol% based on all the dicarboxylic acid components, Preferably it is 4-15 mol%. More preferably, it is 5-13 mol%. By making the ratio of a copolymerization component into this range, the film forming property excellent also in the white reflective layer containing a comparatively large void can be obtained, and the white film excellent in thermal dimensional stability can be obtained.

When a white film consists of multiple layers, it is preferable that a white reflective layer contains fluorescent substance. In this case, the content of the phosphor is preferably 0.1 to 7% by weight based on the weight of the white reflective layer. By including in this range, the luminance can be improved without coloring the white reflective layer by a fluorescent substance, and when using it as a reflective film of an illuminating device, the reflective film which can reproduce accurate color can be obtained.

As the phosphor, both inorganic phosphors and organic phosphors can be used. In order to maintain a stable fluorescent function over a long period of time, inorganic phosphors are preferable. As a fluorescent substance, what is demonstrated below can be used, for example.

As the white colorant or void forming material used for the white film, inorganic particles and organic particles can be used, for example.

As a white coloring agent, it is preferable to use white inorganic particle. When inorganic particles are used as the void forming material, it is preferable to use white inorganic particles. As the white inorganic particles, particles of barium sulfate, titanium dioxide, silicon dioxide and calcium carbonate can be exemplified. The average particle diameter of an inorganic particle is 0.2-3.0 micrometers, Preferably it is 0.3-2.5 micrometers, More preferably, it is 0.4-2.0 micrometers. By using inorganic particles having an average particle diameter in this range, the particles can be suitably dispersed in polyester, and the particles do not easily aggregate, whereby a film without coarse protrusions can be obtained, and at the same time, the surface of the film is too rough. Therefore, glossiness can be controlled to an appropriate range. Moreover, what kind of particle shape may be sufficient as an inorganic particle, for example, plate shape and spherical shape may be sufficient as it. The inorganic particles may be subjected to surface treatment for improving dispersibility.

When using organic particle | grains as a void formation substance, the particle | grains of resin incompatible for polyester are used as organic particle | grains. As such organic particles, silicone resin particles and polytetrafluoroethylene particles are preferable. The average particle diameter of organic particle | grains is 0.2-10 micrometers, Preferably it is 0.3-8.0 micrometers, More preferably, it is 0.4-6.0 micrometers. By using the organic particle | grains of this range, it can disperse | distribute moderately in polyester, and agglomeration of particle | grains does not occur easily, and the film without a coarse protrusion can be obtained.

From the viewpoint of obtaining a high luminance, the light reflectance of the white film is preferably 95% or more, more preferably 96% or more, particularly preferably 97% or more as the reflectance at a wavelength of 550 nm.

Transparent projection

The reflective film for illuminating devices of this invention consists of a white film and the transparent protrusion of 3-50 micrometers in height formed in the surface of this film. The transparent protrusions may be formed continuously or may be formed discontinuously.

In this invention, the coverage by the transparent processus | protrusion of the white film surface is 50 to 100%, Preferably it is 60 to 100%, More preferably, it is 70 to 100%, Especially preferably, it is 80 to 100%. If the coverage is less than 50%, the directivity of the light avoiding the front light source is impaired and brightness improvement cannot be expected.

In the present invention, the coverage is observed for a measurement area having a total length of 6 mm in each of the measurement areas of length 3 mm in two orthogonal directions in the film plane, and transparent projections cover the white film surface in the measurement area. It is defined as the ratio.

Specifically, a slice was cut out using a microtome so that the thickness direction of the film became a cut surface, and the sample was observed at a magnification of 3000 times using a S-4700 type field emission scanning electron microscope manufactured by Hitachi, Ltd. Observation is carried out about the measurement area | region of the total length of 6 mm of the measurement area | region of length 3mm in 2 orthogonal directions inside each other, the length of the part which is not coat | covered with the transparent protrusion in a measurement area is integrated, and is computed by the following formula. .

Coverage ratio = (6 mm-(integrated length (mm) of the part which is not covered by the transparent projection)) / 6 mm x 100 (%)

In addition, when the largest diameter part of a transparent processus | protrude outward from the coating film surface, the part covered with the largest diameter of a transparent particle | grain is considered to be coat | covered with the transparent processus | protrusion.

The transparent protrusions may be formed of a transparent substance, and may be formed of any of an organic substance and an inorganic substance. Moreover, you may form from the mixture of an organic substance and an inorganic substance, and may form from the composite substance of an organic substance and an inorganic substance. The light transmittance of the material forming the transparent projections is, for example, 50% or more, preferably 60% or more, and more preferably 70% or more. In order to prevent coloring, it is preferable that a transparent protrusion does not have absorption of light in a visible region.

The shape of the transparent projection is, for example, a dome shape or a pyramid shape, a pyramidal shape other than the pyramid shape, for example, a triangular pyramid shape, a hexagonal pyramidal shape, an octagonal pyramidal shape, preferably a dome shape or a pyramid shape, in particular Preferably it is a dome shape. The dome-shaped projection may be a projection having a smooth convex surface, preferably a hemispherical surface, a part of a spherical surface or an ellipsoidal surface, and particularly preferably a hemispherical surface. The hemispherical surface is not necessarily half of the sphere, and if a part of the sphere protrudes into the surface in a convex shape, it corresponds to a dome-shaped protrusion.

Although pyramid shape means square pyramid shape, when a transparent protrusion is pyramidal shape, it is preferable that the length of one side of each pyramid bottom is 5-50 micrometers. By setting it as the length of one side of this range, since the fall | off of protrusion can be prevented without inhibiting the effect which gives directivity to reflected light, it is preferable. The shape of the pyramid is preferably a perfect square pyramid, but may be a shape in which a part of the square pyramid is cut off, for example.

The height of the transparent protrusion in this invention is 3-50 micrometers. If the height is less than 3 µm, the directivity of the light is not obtained. If the height is greater than 50 µm, the projections are dropped or the effect of providing the directivity to the reflected light may be greatly changed depending on the design of the backlight, that is, the position of the light source.

When a transparent protrusion is a dome shape, the average diameter of each dome bottom face becomes like this. Preferably it is 5-50 micrometers. By setting it as the average diameter of this range, since the fall | off of protrusion can be prevented without inhibiting the effect which gives directivity to reflected light, it is preferable. In the case of the dome shape, the most preferable shape is hemispherical shape.

As an organic substance which forms a transparent protrusion, UV curable resin, a thermosetting resin, an acrylic resin, a silicone resin, a styrene resin, a urethane resin can be used, for example. Acrylic resin and styrene resin are preferable because there is little absorption of light in the visible light region. As an inorganic substance which forms a transparent protrusion, glass is preferable.

The transparent protrusions can be formed by, for example, arranging a thermosetting resin or a UV curable resin filled in a mold in accordance with the shape of the protrusions on a film and thermally curing or UV curing. It can form by supporting on the surface of. 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, as will be described in detail later.

In the case of using a UV curable resin as the curable resin, an active species such as a radical or a cation capable of reacting the reactive group-containing compound such as a (meth) acryloyl group, a vinyl group or an epoxy group with UV irradiation. What mixed the compound which generate | occur | produces can be used.

In view of the curing rate, 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 radicals by UV light is preferable. As the (meth) acryloyl group compound, for example, 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 of p-cumylphenol which meth) acrylate and ethylene oxide reacted, ethylene oxide addition bisphenol A (meth) acrylic acid ester, propylene oxide addition bisphenol A (meth) acrylic acid ester, bisphenol A diglycidyl ether Bisphenol A epoxy (meth) acrylate obtained by epoxy ring opening of and (meth) acrylic acid, Bisphenol F epoxy (meth) acryl obtained by epoxy ring-opening reaction of bisphenol F diglycidyl ether and (meth) acrylic acid The rate is mentioned.

Projection by transparent particles

The transparent protrusion in the reflective film for illuminating device of the present invention is preferably made of transparent particles supported on the surface of the white film and covering the surface of the white film. That is, the reflective film for illuminating devices of the present invention preferably consists of a white film and transparent particles covering the surface of the white film.

In order to collect light, transparent particle | grains are used by the thing comprised in the curved surface, or the shape comprised in the curved surface and a plane. As this shape, a spherical shape, a rugby ball shape, and a convex lens shape can be used, for example. In order to effectively improve brightness, it is preferable that an aspect ratio is three or less, and also it is preferable that an aspect ratio is 1.2 or less. Particularly preferred shapes are spherical particles. In addition, the aspect ratio is long diameter / short diameter. And the particle diameter of a transparent particle is the value which took the average of the long diameter and the short diameter, when a transparent particle is not spherical.

The size of the transparent particles forming the transparent projections is, for example, from 3 to 50 µm, preferably from 5 to 50 µm, more preferably from 7 to 45 µm, particularly preferably as the average particle diameter according to the measurement by an electron microscope. It is 8-40 micrometers, Most preferably, it is 10-30 micrometers. By using the transparent particle of the average particle diameter of this range, the transparent protrusion of 3-50 micrometers in height can be formed, it is easy to control the directivity of light, and also the particle | grains do not fall easily and apply | coating of stripe shape at the time of coating It is possible to obtain a reflective film in which defects hardly occur.

As for this transparent particle, D10 / D90 which is the ratio of the volume 50% particle diameter D50 of 3-50 micrometers by the measurement by a particle size distribution meter, the volume 10% particle diameter D10, and the volume 90% particle diameter D90 is 0.30-0.98, Furthermore, It is preferable that they are 0.30-0.70. When ratio D10 / D90 is this range, the particle | grains with a small particle size are not buried in a binder, the contribution to a brightness | luminance increase can be acquired, and the fall of the particle | grains with a large particle diameter can be prevented. The larger the ratio D10 / D90 becomes, the sharper the particle size distribution becomes, but since it is difficult to obtain particles of 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 projection in the case of forming the transparent projections into the transparent particles and the particle size of the transparent particles, for example, when the transparent projections are formed by using the transparent particles having an average particle diameter of 20 µm, the transparent particles are halved in the binder. If it is supported on a white film in the buried state, the height of a transparent protrusion will be 10 micrometers. If it is supported on a white film hardly buried in a binder, the height of a transparent projection will be 20 µm.

In the case of forming the transparent projections into transparent particles, the transparent projections formed by the transparent particles are 50 to 100%, preferably 60 to 100%, more preferably 70 to 100%, particularly preferably 80 to 100%. The white film surface is covered by the coverage. That is, the reflecting film of this invention is a reflecting film which consists of a white film and the transparent particle which coat | covers the surface of this white film, 50 to 100% of transparent particle of the exposure rate of 5 to 100% in the surface of the reflecting film. The white film surface is coat | covered at the coverage ratio of. If the coverage by the transparent particles is less than 50%, the directivity of the light is impaired and the brightness increase cannot be expected.

In this invention, the coverage by the transparent particle of a white film observes the measurement area | region whose total length is 6 mm of the measurement area | region of length 3mm, respectively in the orthogonal 2 directions in a film plane, and is white in a measurement area | region It is defined as the ratio which transparent particle coat | covers the film surface.

Specifically, using the microtome, the sample 1 is cut out so that the random direction selected in the film plane and the thickness direction of the film become the cutting plane, and the direction and thickness direction orthogonal to the random one direction selected from the sample sample 1 Sectional sample 2 is cut out so that it may be a cut surface, and about the measurement area which is a total length of 6 mm of the area | region of 3 mm of length of the coating film surface of the binder of the fragment sample 1, and the area of 3 mm of length of the coating film surface of the binder of the fragment sample 2, It was observed at a magnification of 3000 times using a Hitachi, Ltd. S-4700 type field emission scanning electron microscope, and the length of the part of the film surface which is not covered with transparent particles was integrated in the measurement area in the cut surface of the section sample. It is calculated | required by the following formula (refer FIG. 7).

Coverage by transparent particles

= (6 mm-(integrated length (mm) of the part not covered with transparent particles)) / 6 mm x 100 (%)

In addition, when the largest diameter part of a transparent particle is outward from the coating film surface in a cut surface, the part covered with the largest diameter of a transparent particle is considered to be coat | covered by the transparent particle, and the largest diameter part of a transparent particle When inside the coating film surface, ie, when it sinks in the coating film, the largest diameter of the dome-shaped protrusion which the part which goes out from the coating film among transparent particles is considered to be coat | covered with particle | grains.

In the calculation of the coverage by the transparent particles, the transparent particles treated as covering the white film surface are those in which part or all of the transparent particles are exposed on the surface of the reflective film. This exposure refers to the exposure at the exposure rate of 5 to 100%, preferably 10 to 100%, more preferably 20 to 100% at the exposure rate defined in the present invention. Thus, the reason why it is not treated as the particle | grains which coat | covers transparent particle | grains of less than 5% of exposure rates is that when the exposure rate is less than 5%, the light condensing effect by the exposed particle | grains which this invention aims at cannot be obtained.

In a preferable embodiment, the transparent particles are supported on the surface of the white film by a coating film of a binder formed on the surface of the white film. Thus, part of the transparent particles is in contact with or sinks in the coating film of the binder. In addition, 100% of exposure rates correspond to the situation supported by the binder on the surface of a white film in the form which a white film surface and a transparent particle surface contact in a cut surface, and 0% of exposure rate is white in a cut surface. In the coating film of the binder formed in the film surface, the transparent particle completely sank, and in 50% of the exposure rate, half of the transparent particle is filled in the coating film of the binder formed in the white film surface at the cut surface, and the other half is a coating film. Protruding out of.

When the exposure rate is more accurately defined, the exposure rate passes through the center of the transparent particle cross section in the cut plane of the slice sample and draws a straight line perpendicular to the coating surface of the film, whereby the straight line is in the cut plane of the film slice. The point on the surface of the exposed side is S, the point on the surface of the unexposed side is T, and the point where the preceding straight line intersects the coating film surface of the binder is B. It is represented by (distance between S and B) / (distance between S and T).

That is, an exposure rate (%) is defined by the following formula.

Exposure rate = (distance between S and B) / (distance between S and T) × 100 (%)

In addition, when the particle | grain is spherical, the center of the transparent particle cross section in a cut surface shall be the center of the circle of the cross section, and, when particle | grains are non-spherical, it shall be the center of the cross section.

As the transparent particles, both inorganic transparent particles and organic transparent particles can be used. These may use several particle together. The transparent particles preferably have a light transmittance of 50% or more, preferably 60% or more, more preferably 70% or more, and preferably no absorption of light in the visible region.

As the organic transparent particles, for example, acrylic particles, silicon particles, and styrene particles can be used. Since there is little absorption of light in the visible light region, acrylic particles and styrene particles are preferable. As the inorganic transparent particles, for example, glass particles can be used.

The transparent particles forming the transparent projections may be supported so that the particles do not overlap the vertical line direction of the film on the white film, or may be supported so that a large number of the transparent particles overlap the vertical line direction of the white film. In the latter case, 2-30 transparent particles having a particle diameter of 5 to 100 µm may be contained in a direction perpendicular to the film plane 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 adhering the transparent particles to each other with a binder.

In this case, the height of the transparent projection can be determined by specifying the vertex of the transparent particles located on the outermost surface of the transparent particle layer and the reference plane of the binder supporting the same, and measuring the height of the vertex from the reference plane. The reference surface of the binder in this case is a surface which averaged the surface of the binder which coat | covers the other transparent particle which supports the transparent particle of the outermost surface from the lower side (namely, the side near a white film).

bookbinder

As a binder in the coating film of the binder which supports a transparent particle on the surface of a white film, an acrylic resin, a polyester resin, a polyurethane resin, polyesteramide resin, a polyolefin resin, these copolymers, or blends can be used. In addition to the binder mentioned above, a binder may mix | blend and crosslink isocyanate type, melamine type, and epoxy type crosslinking agent.

When the coating film of a binder does not contain fluorescent substance, the quantity of a binder with respect to 100 weight part of transparent particles is 5-200 weight part, Preferably it is 10-100 weight part, More preferably, it is 10-70 weight part. By setting it as the ratio of this range, particle | grains do not fall out and the light condensing effect by transparent particles can be acquired. In addition, although a commercially available binder is sold in the form which the binder solid content, such as an acrylic resin, melt | dissolved in the solvent, the quantity of the binder of the coating film in this invention is the quantity of the binder solid content in the coating film after drying.

It is preferable that the coating film of a binder contains fluorescent substance. That is, in this invention, it is preferable that the transparent particle is supported on the white film by the coating film of the binder composition containing a binder and fluorescent substance. When the fluorescent substance is contained in the binder composition, the ratio of the transparent particles supported on the surface of the film to the binder composition of the coating film is preferably 30 to 70 parts by weight of transparent particles in order to obtain a film without dropping the particles while effectively improving the luminance. It is 70-30 weight part with respect to a binder composition. In addition, a binder composition is the weight of solid content except a solvent.

When a binder composition contains fluorescent substance, it is preferable that content of fluorescent substance is a range whose reflectance film chromaticity in the XYZ colorimeter measured with C light source becomes x = 0.290-0.330, y = 0.300-0.340. Therefore, content of the fluorescent substance in a binder composition becomes like this. Preferably it is 1-20 weight%, 5-20 weight%, More preferably, it is 10-20 weight% based on the weight of a binder composition. If it is less than 1 weight%, the effect of obtaining a high reflectance cannot be acquired. When it exceeds 20 weight%, coloring of the film by a fluorescent substance is large and color deviation arises when used as a reflecting plate of a liquid crystal display device.

Phosphor

When forming a coating film with the binder composition containing a fluorescent substance, as a fluorescent substance, the fluorescent substance which excites by light of 400-450 nm wavelength and emits the wavelength of 500-600 nm is used. 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 if the excitation wavelength is not in this range or the emission wavelength is not in this range There is no coloring and the reflective film which has a high reflectance cannot be obtained. If the excitation wavelength is not in the region of 400 to 450 nm, and is only in the region of less than 400 nm, high reflectance cannot be obtained when used as a reflecting plate, and if it is only in the region exceeding 450 nm, coloration due to absorption of visible light is observed and the white reflective film is observed. Can't get it. When the emission wavelength is not in the region of 500 to 600 nm and in the region of less than 500 nm or more than 600 nm, the effect of improving the reflectance cannot be obtained when used as a reflecting plate of the liquid crystal display device. Can not get

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 fluoresce stably over a long period of time, and it is necessary not to deteriorate or decompose by ultraviolet rays. When the phosphor is deteriorated or decomposed, the film is yellowed, and when used as a reflecting plate of the liquid crystal display device, accurate color reproduction cannot be performed. In addition, when the phosphor deteriorates or decomposes, the phosphor does not emit light, and when used as a reflecting plate of the liquid crystal display device, the luminance by the phosphor decreases. Therefore, as the phosphor in the present invention, an inorganic phosphor is more stable than deterioration or decomposition than an organic phosphor.

As an inorganic phosphor satisfying the requirements for the excitation wavelength and the emission wavelength, an alkaline earth metal sulfide having a rock salt crystal structure, for example, zinc sulfide (ZnS), strontium sulfide (SrS), and yttrium oxide (Y ₂ O ₂ ) As the activator, a phosphor containing europium (Eu) or copper (Cu) can be used. In addition, a phosphor containing barium magnesium aluminum composite oxide (Ba ₃ MgAl ₁₀ O ₁₇ ) as a matrix and containing europium (Eu) or manganese (Mn) as an activator can be used. In addition, a phosphor containing lanthanum phosphate (LaPO ₄ ) as a mother and containing Ce and Tb as an activator can be used.

As what is marketed as an inorganic fluorescent substance, For example, green light-emitting inorganic fluorescent substance 2210 (made by Kasei Optonics Co., Ltd. ZnS as a base material and Cu as a activating material), red inorganic fluorescent substance D1110 (Nemoto specialty chemical company make) , Y ₂ O ₃ as a parent and Eu as the activator, blue inorganic phosphor D1230 (manufactured by Nemoto Special Chemical Co., Ltd., SrS as a parent and Eu as the activator), green inorganic phosphor KX732A a it can be used (by Kasei Optonix Co., Ltd., barium and magnesium-aluminum complex oxide (Ba ₃ MgAl ₁₀ O _17), and the matrix is achieved by a Eu and Mn to a revival material).

Examples of the organic phosphor that satisfies the requirements for the excitation wavelength and the emission wavelength include, for example, a stilbene-based fluorescent agent, a distilbene-based fluorescent agent, a benzoxazole-based fluorescent agent, a styryl-oxazole-based fluorescent agent, and a pyrene-oxazole-based fluorescent agent. Coumarin-based fluorescent agent, imidazole-based fluorescent agent, benzoimidazole-based fluorescent agent, pyrazoline-based fluorescent agent, aminocoumarin-based fluorescent agent, distyryl-biphenyl-based fluorescent agent, naphthalimide-based fluorescent agent can be used. Can be. Among these, since the durability is high and the effect of improving the reflectance is high, a benzoxazole-based fluorescent agent, a styryl-oxazole-based fluorescent agent, and a naphthalimide-based fluorescent agent are preferable, and specifically, East Bright OB-1 ( It is preferable to use the benzoxazole type fluorescent substance manufactured by Eastman company, Uvitex-OB (styryl oxazole type fluorescent substance manufactured by Chiba-Geigi Co., Ltd.), and Lumogen green 850 (naphthalimide type fluorescent substance manufactured by BASF Corporation).

Ray reflectance and chromaticity

The light reflectance of the reflective film for illuminating device of the present invention is preferably 96% or more with respect to light having a wavelength of 550 nm even when the binder composition of the coating film contains neither a phosphor nor a phosphor. When the reflectance is 96% or more, high luminance can be obtained.

When the reflective film for illuminating devices of this invention contains fluorescent substance in the binder composition of a coating film, it is preferable that chromaticity in the XYZ colorimeter measured with C light source is x = 0.290-0.330, y = 0.300-0.340. By being chromaticity of this range, the reflecting plate for lighting devices, especially the reflecting plate for liquid crystal display devices which contain fluorescent substance and are excellent in color reproducibility can be obtained.

UV absorbers

It is preferable that the binder composition of a coating film contains a ultraviolet absorber in order to prevent deterioration by an ultraviolet-ray. As the ultraviolet absorbent 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 ultraviolet absorber, a benzotriazole ultraviolet absorber, a triazine ultraviolet absorber, a cyanoacrylate ultraviolet absorber, a salicylic acid ultraviolet absorber, and benzo Eate type ultraviolet absorbers and oxalate anhydride type ultraviolet absorbers can be used. In the case of an inorganic compound, for example, a silylated modified product such as an alkylcarbamyl adduct of alkoxysilyl or alkanoylsilyl or a hydroxyl group and an epoxy group-containing silane of an aromatic ultraviolet absorber such as 2,4-dihydroxybenzophenone The silylated modified ultraviolet absorber to which the epoxy group of the compound was reacted can be used.

When the binder composition of a coating film contains a ultraviolet absorber, the content should just be an amount which can prevent deterioration of an organic fluorescent substance, and for this reason, what is necessary is just to contain the required amount of ultraviolet absorbers. 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, while preventing an organic fluorescent substance from deteriorating by an ultraviolet-ray effectively, the coating film without coloring can be obtained.

As a ultraviolet absorber, you may use a polymer type thing. In this case, the copolymer polymer which copolymerized the monomer component which has a substituent which has an ultraviolet absorbing power with another monomer component can be used, for example. As this copolymerized polymer, 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 a polymer type, the copolymerization amount of the monomer having a substituent having ultraviolet absorbing capacity is preferably 10% by weight or more, more preferably 20% based on the total amount of all monomers constituting the copolymerized polymer. % Or more, Especially preferably, it is 35 weight% or more. Of course, the homopolymer of the monomer which has a substituent which has an ultraviolet absorbing power may be sufficient. It is less than 10 weight%, and it cannot prevent deterioration by the ultraviolet-ray of an organic fluorescent substance. From the viewpoint of obtaining a tough coating film, the molecular weight of the copolymerized polymer is preferably 5000 or more, more preferably 10000 or more, particularly preferably 20000 or more. These copolymerized polymers can be used as a coating liquid in the state dissolved or dispersed in the organic solvent or water. In addition to these, commercially available hybrid ultraviolet absorbing polymers such as Judable (manufactured by Nippon Catalyst Co., Ltd.) can be used as the ultraviolet absorber.

Light stabilizer

In addition to a ultraviolet absorber, it is preferable to use a light stabilizer together in the binder composition of a coating film from a viewpoint of obtaining the outstanding durability. In this case, the compounding quantity of an optical stabilizer is 0.1-5 weight% based on the weight of a binder composition, for example, Preferably it is 0.5-3 weight%.

As the light stabilizer, a hindered amine light stabilizer is preferable, and specific examples thereof include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and dimethyl succinate.1- (2 -Hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate can be used.

Example

Hereinafter, an Example demonstrates this invention in detail. In addition, the measurement and evaluation were performed with the following method.

(1) relative brightness

The brightness | luminance of the display apparatus at the time of using as a reflecting plate for the liquid crystal display device was evaluated. The 32-inch television (Bravia KDL-32V2500) manufactured by Sony Corporation was removed from the backlight, and the film to be evaluated was installed instead, using a luminance meter (Model Otsuka Electronics Model MC-940). The luminance was measured at a measurement distance of 500 mm from the front of the center of the back light. Relative brightness was calculated by the following formula.

Relative luminance = (luminance of film to be evaluated) / (luminance of reference film) x 100 (%)

The film used as a reference film differs according to the table in which an evaluation result is described. The following films were used as reference films.

Table 1: The film of Comparative Example 1-1 in which no transparent protrusions were formed.

Table 2: The film of the comparative example 2-1 which did not form the processus | protrusion by transparent particle.

Table 3: The film of the comparative example 3-1 which did not form the processus | protrusion by transparent particle.

Table 4: The film of Reference Example 1-1 in which the binder of the coating film did not contain a phosphor.

Table 5: The film of Comparative Example 5-1 in which no projection was formed by transparent particles.

(2) transparent projection

(2-1) Coverage rate of film by transparent protrusion

Using a microtome, the slice was cut out so that the thickness direction of a film might be a cut surface, and it was set as the sample. This fragment sample was observed at a magnification of 3000 times using Hitachi, Ltd. S-4700 type field emission scanning electron microscope. Observation was carried out about the measurement area | region of the total length of 6 mm of the measurement area | region of length 3mm in 2 directions orthogonal in a film surface, and the length of the part which is not coat | covered with the transparent protrusion in a measurement area is integrated, and is represented by the following formula. Obtained.

Coverage ratio = (6 mm-(integrated length (mm) of the part which is not covered by the transparent projection)) / 6 mm x 100 (%)

(2-2) height of transparent projection

The height of the apex was measured about 20 of arbitrary transparent protrusions with the film surface as a reference surface, and these average values were made into the height of transparent protrusions. In addition, when the transparent protrusion was formed of transparent particles and the transparent particles were buried in the binder, the surface of the binder was used as the reference plane. The measurement of the height was performed by cutting out a slice sample from the film using a microtome, and observing and photographing 300 times using this optical microscope with respect to this sample.

(3) transparent particles to form projections

(3-1) Average particle size of transparent particles

Using the Hitachi, Ltd. S-4700 type field emission scanning electron microscope, 100 particles of (raw material) were arbitrarily measured before adding to a resin at 1000 times magnification, and the average particle diameter was calculated | required. When particle | grains are not spherical, (long diameter + short diameter) / 2 was made into the average particle diameter.

(3-2) Aspect Ratio of Transparent Particles

Thirty particles exposed at a magnification of 500 times were randomly observed using a S-4700 type field emission scanning electron microscope manufactured by Hitachi, Ltd., and the average value was calculated from the following values from the values of the long and short diameters.

Aspect ratio = long diameter / short diameter

(3-3) D50 of transparent particles

The particle size distribution of the transparent particle | grains of a raw material was calculated | required with the particle size distribution analyzer (LA-950 by Horiba Corporation), and the particle diameter which 50% of the passing part integration percentage becomes 50 weight% was set to D50.

(3-4) D10 / D90 of the transparent particles

The particle size distribution of the transparent particle | grains of a raw material is calculated | required by a particle size distribution meter (LA-950 by Horiba, Ltd.), the particle diameter which becomes 10 weight% of the pass-through integration percentage is made into D10, and the particle diameter which becomes 90 weight% of the pass-through integration percentage becomes It was set as D90 and D10 / D90 was computed.

(4) Average particle diameter of inorganic particles and organic particles of white film

The average particle diameter of the inorganic particle and organic particle | grains of a white film calculated | required the particle size distribution of raw material particle with a particle size distribution meter (LA-950 by Horiba Corporation), and made the particle diameter in d50 an average particle diameter.

(5) thickness of coating film

The cross section of the film sample was observed and photographed at 5 times magnification with a digital microscope (HIROX Co. Ltd., HI-SCOPE Advanced KH-3000), and the thickness of the binder was determined from the photograph, and ten points were measured at random to obtain their average value. .

(6) film thickness

(6-1) film thickness

The film sample was measured with an electric micrometer (Anritsu K-402B) and the thickness of ten points was made into the average value of the film thickness.

(6-2) thickness of each layer of film

The sample was cut out into triangles, fixed in an embedded capsule, and embedded in an epoxy resin. Then, the embedded sample was microfilm (ULTRACUT-S), the cross section parallel to the longitudinal direction as a thin film slice, then observed and photographed using an optical microscope to measure the thickness ratio of each layer from the photograph, the thickness of the entire film The thickness of each layer was calculated from the calculations.

(7) exposure rate of transparent particles

Using a microtome, the slice sample 1 and the slice sample 2 were cut out from the film. Sectional sample 1 is a sliced sample cut out so that the one direction and thickness direction of the film which are randomly selected in the film surface become a cutting surface, and the sliced sample 2 is a direction which orthogonal to the random one direction selected from the sliced sample 1 is a cutting surface. It is a cut section sample.

S-4700 type field emission type manufactured by Hitachi, Ltd. for the measurement area which is 6 mm in total of the area | region of 3 mm in length of the coating film surface of the binder of the cut sample 1, and the area of 3 mm in length of the coating film surface of the binder of the cutting sample 2 Observation was made at a magnification of 3000 times using a scanning electron microscope.

The exposure rate passes through the center of the transparent particle cross section in the cut surface of the section sample and draws a straight line perpendicular to the coating film surface of the film, where the two points intersect the surface of the transparent particle in the cut surface of the film section. When the point on the surface of the exposed side is S, the point on the surface of the unexposed side is T, and the point where the preceding straight line intersects the coating film surface of the binder is B (S and B Distance between) / (distance between S and T).

That is, an exposure rate (%) is defined by the following formula.

Exposure rate = (distance between S and B) / (distance between S and T) × 100 (%)

In addition, when the particle | grain is spherical, the center of the transparent particle cross section in a cut surface shall be the center of the circle of the cross section, and, when particle | grains are non-spherical, it shall be the center of the cross section.

(8) Coverage rate of film surface by transparent particles

Evaluation was performed about the fragment samples 1 and 2 obtained in the above (7).

S-4700 type field emission type manufactured by Hitachi, Ltd. for the measurement area which is 6 mm in total of the area | region of 3 mm in length of the coating film surface of the binder of the cut sample 1, and the area of 3 mm in length of the coating film surface of the binder of the cutting sample 2 Observation was made at a magnification of 3000 times using a scanning electron microscope.

The coverage was calculated | required by the following formula by integrating the length of the film surface part which is not coat | covered with the transparent particle in the measurement area in the cut surface of a slice sample (refer FIG. 1).

Coverage ratio = (6 mm-(integrated length (mm) of the part which is not covered by transparent particle)) / 6 mm x 100 (%)

(9) extensibility

When extending | stretching by 2.5-3.4 times of longitudinal direction and 3.5-3.7 times of lateral direction, and forming into a film, it observed whether it can form into a film stably and evaluated by the following reference | standard.

○: The film can be stably formed for over 1 hour.

×: Cutting occurred within 1 hour, and stable film formation was not possible.

(10) yellowing over time

The sample of the film was irradiated with a high pressure mercury lamp (Harrison Toshiba Lighting Co., Ltd. "Toscure 401": with a glass filter), and the color change of the sample was evaluated. The irradiation time in this evaluation was made into 50 hours, and the color change before and behind irradiation was evaluated. The irradiance in the irradiation was 18 mW / cm 2. In addition, when the structure of a film formed the reflective layer in the one side of a support layer, it measured from the reflective layer side.

The initial film color (L ₁ ^* , a ₁ ^* , b ₁ ^* ) and the film color (L ₂ ^* , a ₂ ^* , b ₂ ^* ) after irradiation are measured by a color difference meter (SZS-Σ90 COLOR MEASURING, manufactured by Nippon Denshoku Industrial Co., Ltd.). SYSTEM), respectively, the color change dE ^* shown by the following formula was computed, and the following reference | standard evaluated.

dE ^* = {(L ₁ ^* -L ₂ ^* ) ² + (a ₁ ^* -a ₂ ^* ) ² + (b ₁ ^* -b ₂ ^* ) ² } ^1/2

◎: dE ^* ≤ 5

○: 5 <dE ^* ≤ 10

Δ: 10 <dE ^* ≤ 15

×: 15 <dE ^*

(11) Excitation light emission by light of 400-450 nm and emission peak wavelength

Light was incident on the surface on which the phosphor was coated, and the fluorescence spectrum was measured. The measurement was carried out using a fluorescence spectrophotometer F-4500 (manufactured by Hitachi) for an area having an excitation wavelength of 400 to 450 nm and an emission wavelength of 380 to 780 nm. In the case, the emission peak wavelength was calculated | required from the emission spectrum.

(12) Dropping of Particles

An acrylic plate having a side having a right angle of 2 mm in thickness and 20 mm in width was pressed vertically with a load of 300 g on the reflective surface of the film sample, and reciprocated a distance of 30 mm by 10 rounds. The adhesion state of the powder to the acryl plate at this time was visually confirmed, and the following reference | standard evaluated.

(Circle): It is hard to confirm generation | occurrence | production of powder.

X: Generation | occurrence | production of powder can be confirmed.

(13) luminance improvement rate and luminance maintenance rate

(13-1) Brightness Enhancement Rate as Reflector

The film was mounted on the backlight, measured and evaluated. Backlight used is a direct type backlight (20-inch diagonal) unit used for the liquid crystal television (AQUOS-20V made by SHARP company) prepared for evaluation, and it uses the film made into measurement instead of the light reflection sheet originally attached. Mounted. The measurement was carried out by dividing the backlight surface into four sections of 2 × 2 and determining the front luminance after one hour of lighting.

Luminance was measured using BM-7 manufactured by Topcon Corporation. The measuring angle is 1 ° and the distance between the luminance meter and the backlight is 50 cm. The backlight surface is divided into four straight lines 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 longitudinal direction of the backlight surface. The center of each area was made into the measuring point.

The brightness | luminance in four measuring points was measured, and average was just calculated | required and it was set as average luminance. The luminance improvement rate was computed by the following formula using the average luminance calculated | required with the film before and behind coating of fluorescent material.

Luminance improvement ratio = (average luminance after fluorescent material coating) / (average luminance before fluorescent material coating) x 100 (%)

(13-2) Luminance retention rate by durability test

The durability test which made 3000 hours pass with the said backlight lighting in the state which mounted the film of evaluation object was implemented. The luminance retention was calculated by the following formula.

Luminance retention ratio = (average luminance after durability test) / (luminance before durability test) x 100 (%)

(14) chromaticity

(14-1) Chromaticity Difference as a Reflecting Plate

The film was mounted on the backlight, measured and evaluated. Backlight used is a direct type backlight (20-inch diagonal) unit used for the liquid crystal television (AQUOS-20V made by SHARP company) prepared for evaluation, and it uses the film made into measurement instead of the light reflection sheet originally attached. Mounted. The measurement was carried out by dividing the backlight surface into four sections of 2 × 2 and determining the front luminance after one hour of lighting.

Chromaticity was measured using BM-7 manufactured by Topcon Corporation. The measuring angle is 1 ° and the distance between the luminance meter and the backlight is 50 cm. The backlight surface is divided into four straight lines 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 longitudinal direction of the backlight surface. The center of each area was made into the measuring point.

Chromaticity (x, y) in four measuring points was measured, and average was calculated | required simply as average chromaticity (x, y). The distance of average chromaticity (x, y) and a reference color (x = 0.300, y = 0.310) was computed, and chromaticity difference (DELTA) xy was computed.

Δx = reference coordinate (x = 0.300)-measurement coordinate (x)

Δy = reference coordinate (y = 0.310)-measurement coordinate (y)

Δxy = (Δx ² + Δy ² ) ^1/2

The calculated Δxy was evaluated based on the following criteria.

◎: Δxy <0.005

○: 0.005 ≤ Δxy <0.010

×: 0.010 ≤ Δxy

(14-2) Chromaticity Difference by Durability Test

The durability test which made 3000 hours pass with the said backlight lighting in the state which mounted the film of evaluation object was implemented. 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 = coordinate before endurance test (x) —coordinate after endurance test (x)

Δy = coordinate before durability test (y)-coordinate after durability test (y)

Δxy = (Δx ² + Δy ² ) ^1/2

The calculated Δxy was evaluated based on the following criteria.

◎: Δxy <0.005

○: 0.005 ≤ Δxy <0.010

×: 0.010 ≤ Δxy

(14-3) Chromaticity by C Light Source

It measured using the C light source with the color-difference meter (SZS-Σ90 COLOR MEASURING SYSTEM by Nippon Denshoku).

(15) light reflectance

The integrating sphere was attached to the spectrophotometer (UV-3101PC manufactured by Shimadzu Corporation), and the light reflectance when the BaSO ₄ white plate was 100% was measured at a wavelength of 550 nm.

(16) Component and White Film of Coating Film

The component of a coating film is as follows. In a table, "weight%" may be described as "wt%."

<Transparent Particles / Protrusion Formation Material>

MBX-50SS:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 50 μm

MBX-30SS:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 30 μm

MBX-20SS:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 20 μm

MBX-15SS:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 15 μm

MBX-12SS:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 12 μm

MBX-10SS:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 10 μm

MBX-50:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 50 μm

MBX-30:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 30 μm

MBX-20:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 20 μm

MBX-15:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 15 μm

MBX-12:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 12 μm

MBX-8:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 8 μm

MBX-5:

Sekisui Chemicals Co., Ltd. transparent acrylic particles with an average particle diameter of 5 μm

J-120:

Transparent glass particles with an average particle diameter of 105 μm manufactured by Potters-Ballotini

MX-1000:

Soken Chemical Co., Ltd. transparent acrylic particles having an average particle diameter of 10 μm

MX-150:

Soken Chemical Co., Ltd. transparent acrylic particles having an average particle diameter of 2 μm

MR-20G:

Soken Chemical Co., Ltd. transparent crosslinked acrylic particles having an average particle diameter of 20 μm

MR-10G:

Soken Chemical Co., Ltd. transparent crosslinked acrylic particles having an average particle diameter of 10 μm

<Binder>

S2740: Yuda S2740 manufactured by Nippon Catalyst Co., Ltd.

Acrylic binder which consists of 50 weight% of solid resin and 50 weight% of volatile organic solvents

A807BA: Acridique A807BA manufactured by DIC Corporation

Acrylic binder which consists of 50 weight% of solid content acrylic resin and 50 weight% of volatile organic solvents

<Bridge school>

HL: Nippon Polyurethane Industries Colonate HL

Crosslinking agent consisting of 75 weight% of solid content crosslinking agents, and 25 weight% of volatile organic solvents

<Phosphor>

OB-1: East Bright OB-1

Green 850: Lumogen Green 850 manufactured by BASF

Uvitex-OB: Uvitex-OB manufactured by Chiba Electric

<Solvent>

MEK: methyl ethyl ketone

As long as there is no description in an Example and a comparative example as a white film, the film total thickness of 225 micrometers which consists of a total of 2 layers of the reflection layer which consists of a polyester composition containing barium sulfate particle as a void forming agent, and the support layer which consists of polyester A white film (998.5% reflectance of Teijin Tetron UX02-225 reflective layer manufactured by Teijin Dupont Film) was used.

Example 1-1

On the reflective layer of a white film, after apply | coating the coating liquid which consists of a composition shown to the following crude liquid recipe with the die-coating apparatus by the application amount of wet thickness 20g / m <2>, it dried in oven and obtained the reflective film.

Crude recipe 1-1)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-20SS (38 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (20% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Example 1-2

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 10g / m <2>.

Crude recipe 1-2)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-10SS (30 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (28 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: ethyl acetate (40% by weight)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Example 1-3

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 25g / m <2>.

Crude recipe 1-3)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-30SS (32 wt%)

ㆍ Acrylic Binder: DIC Acridick A807BA (25 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvent: methyl ethyl ketone (40 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Example 1-4

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 30g / m <2>.

Crude recipe 1-4)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-50SS (25% by weight)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (38 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: ethyl acetate (34% by weight)

 Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Examples 1-5

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of 15 g / m <2> of wet thickness.

Crude recipe 1-5)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-15SS (19% by weight)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (37% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (4% by weight)

Organic solvents: butyl acetate (40 wt%)

 Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Example 1-6

Square pyramidal protrusions were formed on the entire surface on the reflective layer of the white film without gaps. That is, the coating liquid which consists of a composition shown to the following crude liquid recipe is poured to the metal mold | die made from SUS so that it may become square pyramid, and a white film is stuck on it, and UV light is irradiated with a high pressure mercury lamp (Harrison Toshiba Lighting Co., Ltd. toscure). The coating liquid was cured, dried in an oven at 100 ° C, square pyramids were formed on the entire surface of the reflective surface of the white film to obtain a reflective film. The size of the reflecting film was matched with the size of the reflecting film of the backlight of the Sony Corporation make 32-inch television (Bravia KDL-32V2500) used for evaluation of relative brightness. The schematic diagram of the square pyramid part of the metal mold | die used for square pyramidal protrusion formation is shown in FIG.

Liquid Recipe 1-6) UV Curing Resin

ㆍ DIESEL UC Corporation EB3700

(Bisphenol A type epoxy acrylate) (25% by weight)

ㆍ Shin Nakamura Chemical Company BPE200

(Ethylene Oxide Addition Bisphenol A Methacrylate Ester) (8% by weight)

ㆍ Daiichi Pharmaceutical Industry Co., Ltd. BR-31

(Tribromo phenoxyethyl acrylate) (42 wt%)

ㆍ Toa Synthetic Fiber M-110

((Meth) acrylate of p-cumylphenol reacted with ethylene oxide)

(8% by weight)

BASF LR8893 (radical generator) (1% by weight)

Methyl ethyl ketone (16% by weight)

The evaluation results are shown in Table 1-3.

Example 1-7

On the white film, after coating the coating liquid which has the composition of the crude liquid recipe 6 in Example 1-6 by the application amount of 15 g / m <2> of wet application amounts with a die-coating apparatus, the prism shape shown in FIG. 2 to the coating surface of a film. In the state where the irregularities were formed in the coating layer by using the nip roller having irregularities, the UV light was irradiated and cured by a high-pressure mercury lamp (Harrison Toshiba Lighting Co., Ltd. toscure), and dried in an oven at 100 ° C. to remove the prism shape. Prepared.

In the measurement of the relative luminance in this example, a reflective film was provided so that the flow direction of the prism was parallel to the cold cathode tube of the light source of the backlight.

The evaluation results are shown in Table 1-3.

Example 1-8

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of 15 g / m <2> of wet thickness.

Crude recipe 1-8)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-20SS (38 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (20% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

ㆍ Phosphor: Eastman's East Bright OB-1 (3.4 wt%)

Organic solvents: butyl acetate (36.6 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Example 1-9

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of 15 g / m <2> of wet thickness.

Crude recipe 1-9)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-20SS (38 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (20% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Phosphor: BASF Lumogen Green 850 (2.3 wt%)

Organic Solvent: Butyl Acetate (37.7 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Example 1-10

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of 15 g / m <2> of wet thickness.

Crude recipe 1-10)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-20SS (38 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (20% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

ㆍ Fluorescent substance: Uibatex-OB (2.3% by weight)

Organic Solvent: Butyl Acetate (37.7 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Comparative Example 1-1

The film was evaluated without applying the coating liquid on the white film. The evaluation results are shown in Table 1-3.

Comparative Example 1-2

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 40g / m <2>.

Crude recipe 1-7)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (57% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Comparative Example 1-3

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 2g / m <2>.

Crude recipe 1-8)

ㆍ Protrusion Formation Material: Soken Chemical Co., Ltd. MX-150 (30 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (27% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Comparative Example 1-4

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of wet thickness 80g / m <2>.

Crude recipe 1-8)

ㆍ Protrusion Formation Material: Potters-Ballotini company J-120 (30 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (27% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Comparative Example 1-5

The reflecting film was obtained like Example 1-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 40g / m <2>.

Crude recipe 1-9)

ㆍ Protrusion Formation Material: Sekisui Chemicals, Inc. MBX-50 (3 wt%)

ㆍ Acrylic Binder: DIC Acridique A807BA (50 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic Solvent: Butyl Acetate (44 wt%)

Table 1-2 shows the composition of the obtained reflective film coating film and Table 1-3 shows the evaluation results.

Comparative Example 1-6

Except having changed the shape of the prism formed on the reflective layer of a white film into the shape shown in FIG. 3, it carried out similarly to Example 1-6, and obtained the reflective film in which the prism was formed in the reflective layer. The evaluation results are shown in Table 1-3.

Comparative Example 1-7

Except having changed the shape of the prism formed on the reflection layer of a white film into the shape shown in FIG. 4, it processed to the surface like Example 1-7 and obtained the film. The evaluation results are shown in Table 1-3.

Table 1-1

TABLE 1-2

[Table 1-3]

Example 2-1

On the reflective layer of a white film, after apply | coating the coating liquid which consists of a composition shown to the following crude liquid recipe by the die-coating apparatus by the application amount of wet thickness 25g / m <2>, it dried in oven and obtained the reflective film.

Crude recipe 2-1)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-30SS (35 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (23% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Example 2-2

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of wet thickness 12g / m <2>.

Crude recipe 2-2)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15SS (35 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (23% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Example 2-3

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of wet thickness 40g / m <2>.

Crude recipe 2-3)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-50SS (32% by weight)

ㆍ Acrylic Binder: DIC Acridick A807BA (25 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Examples 2-4

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 10g / m <2>.

Crude recipe 2-4)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-12SS (38 wt%)

ㆍ Acrylic binder: Nippon Catalyst Co., Ltd. Yuda S2740 (25% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: ethyl acetate (34% by weight)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Example 2-5

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of wet thickness 7g / m <2>.

Crude recipe 2-5)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-10SS (19% by weight)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (37% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (4% by weight)

Organic solvents: ethyl acetate (40% by weight)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Example 2-6

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 8g / m <2>.

Crude recipe 2-6)

ㆍ Transparent particle: Soken Chemical Co., Ltd. MX-1000 (40 wt%)

ㆍ Acrylic binder: Nippon Catalyst Co., Ltd. Yuda S2740 (25% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: methyl ethyl ketone (33% by weight)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Comparative Example 2-1

The film was evaluated without applying the coating liquid on the white film. The evaluation results are shown in Table 2-3.

Comparative Example 2-2

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of wet thickness 40g / m <2>.

Crude recipe 2-7)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (57% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Comparative Example 2-3

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 2g / m <2>.

Crude recipe 2-8)

ㆍ Particle: Soken Chemicals MX-150 (30% by weight)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (27% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Comparative Example 2-4

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 80g / m <2>.

Crude recipe 2-9)

ㆍ Particle: Potters-Ballotini company J-120 (30 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (27% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Comparative Example 2-5

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with a coating amount of wet thickness 40g / m <2>.

Crude recipe 2-10)

ㆍ Particle: Sekisui Chemicals, Inc. MBX-50 (3% by weight)

ㆍ Acrylic Binder: DIC Acridique A807BA (50 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic Solvent: Butyl Acetate (44 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

Comparative Example 2-6

The reflecting film was obtained like Example 2-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating with the coating amount of wet thickness 8g / m <2>.

Crude recipe 2-11)

ㆍ Particle: Sekisui Chemicals, Inc. MBX-8 (1% by weight)

ㆍ Acrylic Binder: DIC Acridique A807BA (56% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 2-2 shows the composition of the obtained reflective film coating film, and an evaluation result is shown to Table 2-3.

TABLE 2-1

Table 2-2

[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 parts by weight of diethylene glycol, 0.05 parts by weight of manganese acetate, acetic acid 0.012 parts by weight of lithium was placed in a flask equipped with a rectifying column and an outlet condenser, heated to 150 to 235 ° C. while stirring to distill methanol, and transesterification was carried out. After methanol was distilled off, 0.03 parts by weight of trimethyl phosphate and 0.04 parts by weight of germanium dioxide were added and the reaction was transferred to the reactor. Subsequently, the inside of the reactor was gradually reduced to 0.5 mmHg while stirring, the temperature was raised to 290 ° C, and a polycondensation reaction was carried out to obtain polyester. Barium sulfate particles with 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. A barium sulfate particle and a phosphor having an average particle diameter of 1.2 μm were added to the same polyester, and the polyester composition for a white reflective layer containing 47% by weight of barium sulfate particles and 5.5% by weight of the green light emitting inorganic phosphor KX732A (manufactured by Kasei Optonics). Got.

Using these polyester compositions, the two extruders heated at 270 degreeC were respectively supplied, and the polyester composition for support layers and the polyester composition for white reflection layers were used for the 2-layer feed block apparatus which becomes a laminated structure of a reflection layer / support layer. It joined together, and shape | molded from the dice into the sheet form, maintaining the lamination | stacking state. And the unstretched film which cooled and solidified this sheet | seat by the cooling drum of 25 degreeC of surface temperature was extended | stretched 2.9 times in the longitudinal direction (vertical direction) in the atmosphere heated at 95 degreeC, and cooled in the 25 degreeC roll group. Subsequently, it extended | stretched 3.6 times in the direction (horizontal direction) perpendicular | vertical to the longitudinal direction in the atmosphere heated to 120 degreeC in the atmosphere heated to 120 degreeC, holding both ends of the longitudinally stretched film by the clip. Thereafter, heat setting was performed at a temperature of 215 ° C in a tenter, and then 0.5% in the longitudinal direction and 2.0% in the transverse direction were relaxed, and cooled to room temperature to obtain a white base film that is a biaxially stretched laminated film. The thickness of this white base film was 225 micrometers, and the reflectance of the reflective layer was 98.7%.

Then, 25 g / m <2> was apply | coated to the white reflective layer side by the coating amount which was mix | blended with the following recipe by the butting apparatus, and it dried in oven after that, and obtained the reflective film. The particle diameter and aspect ratio of a transparent particle are put together in Table 3-1, and are shown.

Crude recipe 3-1)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-30 (35 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (23% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3.

Example 3-2

The reflective film was obtained like Example 3-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe.

Crude recipe 3-2)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15 (35 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (23% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3.

Example 3-3

The reflective film was obtained like Example 3-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe.

Crude recipe 3-3)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-50 (32 wt%)

ㆍ Acrylic binder: Nippon Catalyst Co., Ltd. Yuda S2740 (25% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3.

Example 3-4

The reflective film was obtained like Example 3-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe.

Crude recipe 3-4)

ㆍ Transparent particles: Sekisui Chemicals, Inc. MBX-12 (38% by weight)

ㆍ Acrylic binder: Nippon Catalyst Co., Ltd. Yuda S2740 (25% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: ethyl acetate (34% by weight)

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3.

Example 3-5

The reflective film was obtained like Example 3-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe.

Crude recipe 3-5)

ㆍ Transparent particles: Sekisui Chemicals, Inc. MBX-5 (19% by weight)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (37% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (4% by weight)

Organic solvents: ethyl acetate (40% by weight)

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3.

Example 3-6

A reflective film was obtained 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 wt% of the green luminescent inorganic phosphor 2210 (manufactured by Kasei Optonix).

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3.

Example 3-7

A reflective film was obtained 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 wt% of the organic fluorescent whitening agent OB-1 (manufactured by Eastman).

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3.

Comparative Example 3-1

Except not adding a fluorescent substance to the white reflective layer of a white base film, it carried out similarly to Example 3-1, the white base film was obtained, and the white base film was evaluated, without apply | coating a coating liquid to a white base film. The evaluation results are shown in Table 3-3.

Comparative Example 3-3

A reflective film was obtained in the same manner as in Example 3-2 except that the phosphor was not added to the white reflective layer of the white base film and the coating liquid was changed to a coating liquid having a composition shown in the following crude liquid recipe.

Crude recipe 3-6)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15 (10 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (48% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3. Although the color deviation by coloring was small, the rise of brightness was small.

Comparative Example 3-4

A reflective film was obtained in the same manner as in Example 3-2 except that the phosphor was not added to the white reflective layer of the white base film and the coating liquid was changed to a coating liquid having a composition shown in the following crude liquid recipe.

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15 (2 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (56% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3. Although the color deviation by coloring was small, the rise of brightness was small.

Comparative Example 3-5

The white base film of Example 3-2 was evaluated in the state in which the coating liquid was not apply | coated to the white base film. The evaluation results are shown in Table 3-3. Although the color deviation by coloring was small, the rise of brightness was small.

Comparative Example 3-6

The white base film of Example 3-6 was evaluated in the state in which the coating liquid was not apply | coated to the white base film. The evaluation results are shown in Table 3-3. Although the color deviation by coloring was small, the rise of brightness was small.

Comparative Example 3-7

The white base film of Example 3-7 was evaluated in the state in which the coating liquid was not apply | coated to the white base film. The evaluation results are shown in Table 3-3. Although the color deviation by coloring was small, the rise of brightness was small.

Comparative Example 3-8

A reflective film was obtained in the same manner as Comparative Example 3-5 except for changing the addition amount of the green light-emitting inorganic phosphor KX732A added to the reflective layer of the white base film to 17 wt%. Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3. Although the brightness | luminance rise was large, the color deviation by coloring was large and it was difficult to use practically.

Comparative Example 3-9

A reflective film was obtained in the same manner as Comparative Example 3-5 except for changing the addition amount of the green light-emitting inorganic phosphor 2210 added to the reflective layer of the white base film to 8 wt%. Table 3-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 3-3. Although the brightness | luminance rise was large, the color deviation by coloring was large and it was difficult to use practically.

Table 3-1

Table 3-2

Table 3-3

Example 4-1

On the reflective layer of a white film, after apply | coating the coating liquid which consists of a composition shown to the following crude liquid recipe by the die coating apparatus so that the binder thickness after drying might be set to 4 micrometers, it dried in the oven and obtained the reflective film.

Crude recipe 4-1)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15SS (35 wt%)

ㆍ Phosphor: Kasei Optonix KX-732A (10 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (23% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (30% by weight)

Table 4-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown to Table 4-3.

Example 4-2

The reflective film was obtained like Example 4-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating so that the binder thickness after drying might be set to 8 micrometers.

Crude recipe 4-2)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-50SS (32% by weight)

ㆍ Phosphor: Kasei Optonix KX-732A (10 wt%)

ㆍ Acrylic Binder: DIC Acridick A807BA (25 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (30% by weight)

Table 4-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown to 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 a composition shown in the following crude liquid recipe and applied.

Crude recipe 4-3)

ㆍ Transparent particle: Soken Chemical Co., Ltd. MX-1000 (40 wt%)

ㆍ Phosphor: Kasei Optonix Corporation 2210 (5% by weight)

ㆍ Acrylic binder: Nippon Catalyst Co., Ltd. Yuda S2740 (25% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvent: methyl ethyl ketone (28 wt%)

Table 4-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown to 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 a composition shown in the following crude liquid recipe and applied.

Crude recipe 4-4)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15SS (35 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (23% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (2% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 4-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown to 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 a composition shown in the following crude liquid recipe and applied.

Crude recipe 4-5)

ㆍ Phosphor: Kasei Optonix KX-732A (10 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (57% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic solvents: butyl acetate (30% by weight)

Table 4-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown to 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 a composition shown in the following crude liquid recipe and applied.

Crude recipe 4-6)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15SS (3 wt%)

ㆍ Phosphor: Kasei Optonix Corporation 2210 (5% by weight)

ㆍ Acrylic Binder: DIC Acridique A807BA (50 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (3% by weight)

Organic Solvent: Butyl Acetate (39% by weight)

Table 4-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown to Table 4-3.

Comparative Example 4-6

The film was evaluated without applying the coating liquid on the white film. The evaluation results are shown in Table 4-3.

Table 4-1

Table 4-2

Table 4-3

Example 5-1

On the reflective layer of a white film, after apply | coating the coating liquid which consists of a composition shown to the following crude liquid recipe with the die-coating apparatus so that the binder thickness after drying might be set to 8 micrometers, it dried in the oven and obtained the reflective film.

Crude recipe 5-1)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-12 (35 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (21 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (4% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 5-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 5-3.

Example 5-2

The reflecting film was obtained like Example 5-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating so that the binder thickness after drying might be set to 10 micrometers.

Crude recipe 5-2)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-15 (35 wt%)

ㆍ Acrylic Binder: DIC Acridick A807BA (21 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (4% by weight)

Organic solvent: methyl ethyl ketone (40 wt%)

Table 5-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 5-3.

Example 5-3

The reflecting film was obtained like Example 5-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating so that the binder thickness after drying might be set to 14 micrometers.

Crude recipe 5-3)

ㆍ Transparent particle: Sekisui Chemicals, Inc. MBX-20 (35 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (21 wt%)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (4% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 5-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 5-3.

Comparative Example 5-1

The film was evaluated without applying the coating liquid on the white film. The evaluation results are shown in Table 5-3.

Comparative Example 5-3

The reflective film was obtained like Example 5-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating so that the binder thickness after drying might be set to 6 micrometers.

Crude recipe 5-4)

ㆍ Transparent particle: Soken Chemicals MR-10G (15 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (37% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (8% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 5-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 5-3.

Comparative Example 5-5

The reflecting film was obtained like Example 5-1 except having changed the coating liquid into the coating liquid which consists of a composition shown to the following crude liquid recipe, and apply | coating so that the binder thickness after drying might be set to 14 micrometers.

Crude recipe 5-5)

ㆍ Transparent particle: Soken Chemical Co., Ltd. MR-20G (15 wt%)

ㆍ Acrylic Binder: Nippon Catalyst Co., Ltd. Yuda S2740 (37% by weight)

ㆍ Crosslinking agent: Nippon Polyurethane Industry Colonate HL (8% by weight)

Organic solvents: butyl acetate (40 wt%)

Table 5-2 shows the composition of the obtained reflective film coating film, and the evaluation result is shown in Table 5-3.

Table 5-1

Table 5-2

Table 5-3

Industrial availability

The reflecting film for illuminating device of this invention can be used as a reflecting plate of an illuminating device, and also as a reflecting film of the backlight unit of a liquid crystal display device of the backlight system which places a light source on the back surface of display apparatuses, such as a liquid crystal television especially. It can use suitably as a reflective film used for the backlight unit of a liquid crystal display device.

Claims (8)

A reflective film for a lighting device, comprising a white film and a transparent projection having a height of 3 to 50 µm formed on the surface of the white film, and the coverage by the transparent projection on the surface of the white film is 50 to 100%. The method of claim 1,
The reflective film for illuminating devices in which a transparent protrusion consists of transparent particle | grains, and the transparent particle of 5-100% of exposure rate coat | covers the surface of a white film at 50-100% of coverage on the surface of a reflective film. The method of claim 2,
The reflective film for illuminating devices in which transparent particle is supported by the coating film of a binder on the surface of a white film. The method of claim 2,
The reflective film for illuminating devices whose average particle diameter of a transparent particle is 3-50 micrometers. The method of claim 4, wherein
The reflecting film for illumination devices whose ratio D10 / D90 of the volume 50% particle size D50 of a transparent particle is 3-50 micrometers, and the volume 10% particle size D10 of a transparent particle, and the volume 90% particle size D90 is 0.30-0.98. The method of claim 3, wherein
The coating film of a binder consists of a binder composition containing fluorescent substance, The content of fluorescent substance in this binder composition is 1-20 weight% based on the total weight of a binder composition, The reflecting film for illuminating devices. The method according to claim 6,
The reflective film for illuminating devices whose fluorescent substance is an organic fluorescent substance which excites by light of the wavelength of 400-450 nm, and emits light of the wavelength of 500-600 nm. The method according to any one of claims 1 to 7,
Reflective film for illuminating devices whose illuminating device is a backlight unit of a liquid crystal display device.

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