TWI500883B - Reflective film for lighting fixtures - Google Patents

Description

Reflective film for lighting devices

The present invention relates to a reflective film used in an illumination device, and more particularly to a reflective film for an illumination 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 in which a light source is placed on the back surface of the backlight unit, and a backlight method in which a light source is placed on the side surface. In either manner, in order to prevent light from the light source from escaping to the back side of the screen, a reflective film is disposed on the back surface of the backlight unit. The reflective film is required to have a thin and high reflectance.

Conventionally, a white film in which a white pigment is added to a polyester is used as the reflective film (Japanese Laid-Open Patent Publication No. 2004-050479, JP-A-2004-330727), or a white film containing fine bubbles inside (Specially Opened 6) Japanese Unexamined Patent Publication No. Hei No. No. 322-153, No. Hei-7-118433.

In the liquid crystal display device of the backlight type, the improvement of the brightness can be achieved by increasing the reflectance of the reflective film to a certain extent, but there is a certain critical value when only the reflectance is increased.

In addition to improving the reflectance of the film itself, the method of improving the brightness is to review the fluorescent whitening agent in the reaction film, and it is proposed to apply a fluorescent whitening agent on the surface of the reflective film (JP-A-2002-40214) . However, in general, since the backlight unit uses a cold cathode tube as a light source, when the fluorescent whitening agent is coated on the surface of the white film, the purple light emitted from the self-cooling cathode line tube The outer line causes the fluorescent whitening agent to deteriorate and loses the effect of improving the temporal reflectance. When the ultraviolet light absorber is used to prevent deterioration of the fluorescent whitening agent caused by ultraviolet rays, since the fluorescent whitening agent originally exhibits blue light rays excited by ultraviolet rays, it cannot be obtained by blending the ultraviolet light absorber. Fluorescent whitening agent to improve the effect of reflectivity.

The present inventors have focused on that when the specular reflection of the reflective film is strong, the light source itself disposed in the backlight unit and in front of the reflective film, that is, between the reflective film and the display surface, returns to form reflected light, and the light cannot reach the display surface. Light loss is generated, which causes a decrease in brightness.

The present invention provides a method for suppressing specular reflection by a reflective film, and reflecting the reflected light to avoid directivity of the front light source, and is used as a reflective film in a backlight unit of a backlight type liquid crystal display device. A reflective film for a luminance illumination device is a problem.

A second object of the present invention is to provide a reflective film for an illumination device which is excellent in processability when used as a reflective film in a backlight unit of a liquid crystal display device of a backlight type.

According to a third aspect of the present invention, in a backlight unit of a liquid crystal display device of a backlight type, when a reflective film is used, it is possible to obtain high brightness and a small color mismatch, and to suppress reflection of a yellowing device. film.

In other words, the reflective film for a lighting device of the present invention is characterized in that a white film and a height set on the surface of the white film are 3 to 50 μm. The transparent protrusion is formed, and the coverage of the surface of the white film by the transparent protrusion is 50 to 100%.

In a preferred embodiment of the present invention, the transparent protrusion is formed of transparent particles, and the transparent particles having an exposure ratio of 5 to 100% on the surface of the reflective film are coated on the surface of the white film at a coverage of 50 to 100%. In other words, it is formed by a transparent protrusion having a height of 3 to 50 μm by a white film and transparent particles covering the surface of the white film, and the transparent particles having an exposure rate of 5 to 100% on the surface of the white film are 50 to 100%. A reflective film for an illumination device coated with a white film surface is preferably a preferred embodiment.

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

Secondly, according to the present invention, it is possible to provide a reflective film for an illumination device which is excellent in processability when used as a reflective film in a backlight unit of a liquid crystal display device of a backlight type.

Thirdly, according to the present invention, when a reflective film is used as a reflective film in a backlight unit of a liquid crystal display device of a backlight type, it is possible to obtain a high-brightness color and a color mismatch, and it is possible to suppress the reflection of the illuminating device over time. film.

[In order to implement the best form of the invention]

The invention will be described in detail below.

White film

The white film of the present invention is formed of a thermoplastic resin and exhibits a white film by containing a white coloring agent or void forming material in the film.

The thermoplastic resin constituting the film, such as polyester, polyolefin, and polystyrene, is preferably a polyester in terms of both mechanical properties and thermal stability.

When polyester is used as the thermoplastic resin of the white film, the polyester is a polyester formed of a dicarboxylic acid component and a diol component. The dicarboxylic acid component is, for example, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, adipic acid or sebacic acid. The diol component is, for example, ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, or 1,6-hexanediol.

Among these polyesters, aromatic polyesters are preferred, and polyethylene terephthalate is more preferred. Polyethylene terephthalate may also be a homopolymer, but a copolymerized polymer is preferred.

The white film may be formed of a single layer or may be formed of a plurality of layers. When the white film is formed of a plurality of layers, it is preferable to form a laminated film formed of a white reflective layer that reflects light and a support layer that carries the layer. In the laminated film, the white reflective layer is a layer containing a large number of voids, and the support layer is preferably a layer containing less or no voids. The polyester used in the white reflective layer is preferably a copolymerized polyester, and the ratio of the copolymerized component is based on the total dicarboxylic acid component, for example, 3 to 20 mol%, preferably 4 to 15 mol. %, the better is 5~13 mole%. When the ratio of the copolymerization component is within this range, the white reflective layer containing a large number of voids can also have excellent film forming properties, and a white film excellent in thermal dimensional stability can be obtained.

When the white film is formed of a plurality of layers, the white reflective layer preferably contains a fluorescent material. In this case, the content of the phosphor is preferably from 0.1 to 7% by weight based on the white reflective layer. By including the amount in the range, the white reflective layer is not colored by the phosphor, and the brightness can be improved. When a reflective film as an illumination device is used, a reflective film which can be reproduced in a correct color can be obtained.

As the phosphor, any of inorganic phosphors and organic phosphors can be used. In order to maintain a stable fluorescent function after a long period of time, it is preferred to use an inorganic fluorescent material. For the fluorescent substance, for example, the following description can be used.

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

The white colorant is preferably a white inorganic particle. When inorganic particles are used as the void-forming material, it is preferred to use white inorganic particles. White inorganic particles such as barium sulfate, titanium dioxide, cerium oxide, calcium carbonate particles. The average particle diameter of the inorganic particles is, for example, 0.2 to 3.0 μm, preferably 0.3 to 2.5 μm, and more preferably 0.4 to 2.0 μm. By using inorganic particles having an average particle diameter within the range, it can be appropriately dispersed in the polyester without causing aggregation of the particles, and a film having no coarse protrusions can be obtained, and the surface of the film is not too rough. The gloss is controlled within an appropriate range. Further, the inorganic particles may have any particle shape such as a plate shape or a spherical shape. The inorganic particles may also be subjected to a surface treatment for improving the dispersibility.

When organic particles are used as the void-forming material, incompatible resin particles are used as the organic particles in the polyester. The organic particles are preferably polyaluminoxane resin particles or polytetrafluoroethylene particles. The average particle diameter of the organic particles is, for example, 0.2 to 10 μm, preferably 0.3 to 8.0 μm, and more preferably 0.4 to 6.0 μm. By using the organic particles in this range, it can be suitably dispersed in the polyester without causing aggregation of the particles, and a film having no coarse protrusions can be obtained.

In terms of high luminance, the reflectance of the light reflectance of the white film at a wavelength of 550 nm is preferably 95% or more, more preferably 96% or more, and most preferably 97% or more.

Transparent protrusion

The reflective film for an illumination device of the present invention is formed of a white film and a transparent protrusion having a height of 3 to 50 μm provided on the surface of the film. The transparent protrusions may be provided continuously or discontinuously.

In the present invention, the coverage of the surface of the white film by the transparent protrusions is 50 to 100%, preferably 60 to 100%, most preferably 70 to 100%, and more preferably 80 to 100%. When the coverage rate is less than 50%, the directivity of the light that avoids the front light source is impaired, and the brightness cannot be expected to be improved.

In the present invention, the coverage ratio is defined as a measurement range in which the total length of the measurement range of 3 mm in each of the two perpendicular directions in the plane of the film is 6 mm, and the ratio of the surface of the white film to the transparent protrusion is defined in the measurement range.

Specifically, a sheet slicing device was used, and a sliced surface was cut into a sliced surface in the thickness direction of the film, and an S-4700-shaped electric field discharge scanning electron microscope manufactured by Hitachi, Ltd. was used, and the sample and the sliced sample were observed at a magnification of 3000 times. The measurement range in which the total length of the measurement range of 3 mm in each of the two perpendicular directions in the plane of the film was 6 mm was observed, and the length of the portion which was not covered by the transparent protrusion in the cumulative measurement field was obtained by the following formula.

Coverage ratio = (6 mm - (accumulated length (mm) of the portion without the transparent protrusion)) / 6 mm × 100 (%)

Further, when the maximum diameter portion of the transparent projection is exposed to the outside from the surface of the coating film, the portion covered with the largest diameter of the transparent particles is covered with the transparent projection.

The transparent protrusions can be formed of a transparent substance or any substance of an organic substance and an inorganic substance. Further, it may be formed of a mixture of an organic substance and an inorganic substance, or may be formed of a composite of an organic substance and an inorganic substance. The light transmittance of the substance forming the transparent protrusion is, for example, 50% or more, preferably 60% or more, and more preferably 70% or more. The transparent protrusions can absorb light in the visible light range in order to prevent coloration.

The shape of the transparent protrusion, such as a dome shape or a pyramid shape, a pyramid shape other than the pyramid shape, such as a triangular pyramid shape, a hexagonal pyramid shape, an octagonal hammer shape, preferably a dome shape or a pyramid shape, preferably The shape is a dome. The protrusion of the dome shape may be a protrusion having an inclined convex surface, and it is preferable to have a hemispherical surface, a partial spherical surface or a spheroidal ellipsoidal surface, and a hemispherical surface is more preferable. The hemispherical surface does not necessarily have to be half of the ball, as long as a part of the spherical surface protrudes convexly on the surface, which corresponds to a dome-shaped protrusion.

The pyramid shape refers to a quadrangular pyramid shape, and when the transparent protrusions have a pyramid shape, the length of one side of each pyramid bottom surface is preferably 5 to 50 μm. By forming the length of one side of the range, it is possible to prevent the protrusion from falling off, without impairing the effect of imparting directivity to the reflected light. The shape of the pyramid is preferably a full quadrangular pyramid, but one of the quadrangular pyramids may also have a shape in which the apex is cut off, for example.

In the present invention, the height of the transparent protrusions is 3 to 50 μm. When the height is less than 3 μm, the directivity of light cannot be obtained. When the height exceeds 50 μm, the protrusions are detached, and the effect of imparting directivity to the reflected light is significantly changed by the design of the backlight (that is, the position of the light source).

When the transparent protrusion has a dome shape, the average diameter of each of the dome-shaped bottom surfaces is preferably 5 to 50 μm. By forming the average diameter of the range, it is preferable to prevent the protrusion from falling off without impairing the directivity imparted to the reflected light. When it is in the shape of a dome, the optimum shape is hemispherical.

As the organic substance forming the transparent protrusion, for example, a UV curable resin, a thermosetting resin, an acrylic resin, a polyoxyalkylene resin, a styrene resin, or a urethane resin can be used. Acrylic resin and styrene resin are preferred because there is almost no absorption of light in the visible light range. The inorganic material forming the transparent protrusion is preferably glass.

The transparent protrusions may be formed, for example, by placing a thermosetting resin or a UV curable resin in a mold conforming to the shape of the protrusions on the film, and forming them by heat hardening or UV curing, for example, by using transparent particles as a binder. It is formed on the surface of a white film. The former method is a preferred method for forming pyramid-shaped protrusions; the latter method is described in detail as a preferred method for forming dome-shaped protrusions as follows.

When a UV curable resin is used as the curable resin, a compound containing a reactive group such as a (meth)acryl fluorenyl group, a vinyl group or an epoxy group may be used, and the reactive group may be produced by UV irradiation. A mixture of compounds of the free radical or cationic active species obtained by the reaction of the compound.

In terms of the rate of hardening, a compound (monomer) which combines a reactive group containing an unsaturated group such as a (meth) acrylonitrile group or a vinyl group, and a photo radical polymerization which generates a radical by UV light are used. The agent is preferred. (Meth)acrylonitrile compound, such as 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, (A) 3-(2-phenylphenyl)-2-hydroxypropyl acrylate, (meth) acrylate of p- cumenylphenol reacted with ethylene oxide, bisphenol A (methyl) Bisphenol A (meth) acrylate obtained by acrylate, propylene oxide addition bisphenol A (meth) acrylate, bisphenol A diglycidyl ether and (meth)acrylic acid ring-opened by epoxy group An epoxy ester of bisphenol F (meth)acrylate obtained by ring-opening reaction of epoxy ester, bisphenol F diglycidyl ether and (meth)acrylic acid.

Protrusion made of transparent particles

The transparent protrusion in the reflective film for an illumination device of the present invention is preferably formed by being coated on a surface of a white film and coated with transparent particles on the surface of the white film. In other words, the reflective film for an illumination device of the present invention is preferably formed of a white film and transparent particles covering the surface of the white film.

When the transparent particles are used to collect light, a shape formed by a curved surface or a curved surface and a flat surface is used. For the shape, for example, a spherical shape, a football shape, or a convex lens shape can be used. In order to effectively increase the brightness, it is preferable that the aspect ratio is 3 or less, and it is more preferable that the aspect ratio is 1.2 or less. A more preferred shape is a spherical particle. Moreover, the aspect ratio is a long diameter/short diameter. Next, the particle diameter of the transparent particles is an average value of the long diameter and the short diameter when the transparent particles are not spherical.

The size of the transparent particles forming the transparent protrusions is, for example, 3 to 50 μm, preferably 5 to 50 μm, more preferably 7 to 45 μm, and particularly preferably 8 to 40 μm, most preferably measured by an electron microscope. The best is 10 to 30 μm. By using transparent particles having an average particle diameter in this range, transparent protrusions having a height of 3 to 50 μm can be formed, and directivity of light can be easily controlled, and particles are less likely to fall off, and strip coating is less likely to occur during coating. Defect, a reflective film is produced.

The transparent particles are measured by a particle size distribution meter, and the volume 50% particle diameter D50 is 3 to 50 μm, and the ratio of the volume 10% particle diameter D10 to the volume 90% particle diameter D90 is D10/D90 is 0.30 to 0.98, preferably 0.30 to 0.70. When the ratio D10/D90 is within this range, particles having a small particle diameter are not embedded in the binder, and brightness enhancement property can be imparted, and particles having a large particle diameter can be prevented from falling off. The larger the ratio of D10/D90, the more pronounced the particle size distribution is. Since the particles having a single particle diameter are not easily obtained, the upper limit of the ratio D10/D90 is, for example, 0.98.

When the transparent protrusions are formed into transparent protrusions, the relationship between the height of the protrusions and the particle diameter of the transparent particles, for example, when transparent protrusions are formed using transparent particles having an average particle diameter of 20 μm, the transparent particles are carried in a white film in a state in which half of the particles are buried in the binder. On the upper side, the height of the transparent protrusions was 10 μm. The height of the transparent protrusions was 20 μm when carried on a white film almost completely without being buried in the adhesive.

When the transparent protrusion is formed of transparent particles, the transparent protrusion formed by the transparent particles is 50 to 100%, preferably 60 to 100%, more preferably 70 to 100%, and most preferably 80 to 100%. The coverage rate is coated on the surface of the white film. In other words, the reflective film of the present invention is a reflective film formed of a white film and transparent particles coated on the surface of the white film, and a transparent particle having an exposure ratio of 5 to 100% on the surface of the reflective film is 50 to 100%. The coverage rate is coated on the surface of the white film. When the coverage ratio by the transparent particles is less than 50%, the directivity of light is impaired, and improvement in luminance cannot be expected.

In the present invention, the coverage of the white film by the transparent particles is such that the total length of the measurement range of 3 mm in each of the two perpendicular directions in the plane of the film is 6 mm, and white is measured within the measurement range. The ratio of the film-coated transparent particles is defined.

Specifically, in the slice slicer, the sliced sample 1 is cut out by arbitrarily selecting one direction and the thickness direction of the film as the cut surface, and the slice sample 1 is arbitrarily selected in a direction perpendicular to one direction, and The thickness direction of the film was used as the cut surface, and the sliced sample 2 was cut out, and the length of the coated surface of the adhesive of the sliced sample 1 was 3 mm, and the length of the coated surface of the adhesive of the sliced sample 2 was 3 mm. The measurement range of the total length of 6 mm was observed by using an S-4700 electric field discharge scanning electron microscope manufactured by Hitachi, Ltd., and observed at a magnification of 3000 times. In the measurement range in the cut surface of the sliced sample, the accumulation was not covered by the transparent particles. The length of the portion of the film surface is obtained by the following formula (see Fig. 7). The coverage ratio by the transparent particles = (6 mm - (accumulated length (mm) of the portion not covered by the transparent particles)) / 6 mm × 100 (%)

Further, when the maximum diameter portion of the transparent particles on the cut surface is exposed to the outside from the surface of the coating film, the portion covered with the largest diameter of the transparent particles is regarded as a portion covered by the transparent particles, and the largest diameter portion of the transparent particles is self-coated. When the surface is exposed to the inside, that is, when it sinks in the coating film, the maximum diameter of the dome-shaped projection in the portion where the self-coating film is exposed to the outside in the transparent particles is considered to be the portion covered by the particles.

When the coverage is obtained from the transparent particles, the transparent particles used to cover the surface of the white film are transparent particles partially or entirely exposed on the surface of the reflective film. The exposure means that the exposure ratio defined by the present invention is 5 to 100%, preferably 10 to 100%, and more preferably 20 to 100%. In this way, the transparent particles treated with the exposure rate of less than 5% are not coated, and when the exposure rate is less than 5%, the light collecting effect by the exposed particles of the object of the present invention cannot be obtained.

In a preferred embodiment, the transparent particles are carried on the surface of the white film by a coating film of an adhesive disposed on the surface of the white film. Therefore, part of the transparent particles are attached or sunk into the coating film of the binder. Further, the exposure rate is 100%, which is attached to the cut surface to connect the surface of the white film to the surface of the transparent particle, and is carried by the adhesive on the surface of the white film; the exposure rate is 0%, and the transparent particles are cut on the cut surface. a state of being completely sunk into the coating film of the adhesive provided on the surface of the white film; the exposure rate is 50%, and half of the transparent particles on the cut surface are buried in the coating film of the adhesive provided on the surface of the white film, Half of the residual component protrudes from the outside of the coating film.

When a more accurate exposure ratio is defined, the exposure ratio is such that when a straight line perpendicular to the coating film surface of the film is drawn through the center of the cross section of the transparent particles in the cut surface of the sliced sample, the straight line is in the cut surface of the film slice Among the two points intersecting the surface of the transparent particle, the point on the surface on the exposed side is S, and the point on the surface on the unexposed side is T, and the point at which the straight line intersects the coating surface of the adhesive is B, The distance between S and B) / (the distance between S and T) is expressed.

In other words, the exposure rate (%) is defined by the following formula.

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

Further, the center of the cross section of the transparent particles in the plane is cut, and when the particles are spherical, the center of the circle is the center of the cross section; and when the particles are non-spherical, the center of gravity of the cross section.

As the transparent particles, any of inorganic transparent particles and organic transparent particles can be used. These can also be used in combination with several types of particles. The transparent particles constitute a material having a light transmittance of 50% or more, preferably 60% or more, more preferably 70% or more, and preferably no light is absorbed in the visible light range.

As the organic transparent particles, for example, acrylic particles, polyoxyalkylene particles, or styrene particles can be used. Acrylic particles and styrene particles are preferred because there is almost no absorption of light in the visible light range. Further, as the inorganic transparent particles, for example, glass particles can be used.

The transparent particles forming the transparent protrusions can be supported on the white film in the vertical direction of the film and without overlapping of the particles, and the transparent particles can be carried under the overlap of the vertical direction of the white film. In the latter case, 2 to 30 transparent particles having a particle diameter of 5 to 100 μm may be contained in a direction perpendicular to the surface of the film from the surface of the white film to the surface of the transparent particle layer. At this time, the transparent particle layer causes the transparent particles to adhere to each other by the binder, and is carried on the white film.

At this time, the height of the transparent protrusion is determined by measuring the height from the reference surface to the vertex by specifying the vertex of the transparent particle located on the outermost surface of the transparent particle layer and the reference surface of the adhesive supporting the object. The reference surface of the adhesive at this time is such that the transparent particles on the outermost surface are coated on the surface from which the surface of the adhesive carrying the other transparent particles is averaged from the lower side (i.e., the side close to the white film).

Adhesive

The adhesive for supporting the transparent particles on the adhesive coating film on the surface of the white film may be acrylic acid, a polyester resin, a polyurethane, a polyester amide resin, a polyolefin resin, or a copolymer or a mixture thereof. The binder may be crosslinked by an isocyanate-based, melamine-based or epoxy-based crosslinking agent in addition to the above-mentioned binder.

When the coating film of the binder does not contain a fluorescent material, the amount of the binder relative to 100 parts by weight of the transparent particles is, for example, 5 to 200 parts by weight, preferably 10 to 100 parts by weight, more preferably 10 to 10 parts by weight. 70 parts by weight. By the ratio of the range, the particles can be prevented from falling off, and the light collecting effect by the transparent particles can be obtained. Further, the commercially available adhesive is sold in such a manner that the binder solid component such as an acrylic resin is dissolved in a solvent, but the amount of the binder of the coating film of the present invention is the binder in the dried coating film. The amount of ingredients.

The coating film of the adhesive preferably contains a fluorescent material. In other words, in the present invention, the transparent particles are preferably supported on the white film by a coating film comprising a binder composition containing a binder and a phosphor. When the phosphor composition contains a fluorescent material, the ratio of the transparent particles carried on the surface of the film to the adhesive composition of the coating film is preferably a film which can effectively increase the brightness and obtain a film having no particles falling off. The binder composition is 70 to 30 parts by weight based on 30 to 70 parts by weight of the transparent particles. Moreover, the binder composition is a solid component weight other than the solvent.

When the binder composition contains a phosphor, the content of the phosphor is preferably in the range of x=0.290 to 0.330 and y=0.300 to 0.340 of the XYZ color system of the reflective film measured by the C light source. Therefore, the content of the phosphor in the binder composition is preferably from 1 to 20%, from 5 to 20% by weight, and more preferably from 10 to 20% by weight based on the weight of the binder composition. When it is less than 1% by weight, the effect of high reflectance cannot be obtained. When it is more than 20% by weight, the coloring of the film is large due to the phosphor, and when the reflector is used as a liquid crystal display device, color mismatch is caused.

Fluorescent

When a coating film is formed by a binder composition containing a phosphor, the phosphor is a phosphor that is excited by light having a wavelength of 400 to 450 nm to emit light at a wavelength of 500 to 600 nm. This means that the excitation wavelength of the phosphor of the present invention is in the range of 400 to 450 nm, and the emission wavelength is 500 to 600 nm. However, when the excitation wavelength is out of the range or the emission wavelength is out of the range, no coloring can be obtained. In case of reflection film with high reflectivity. When the excitation wavelength is not in the range of 400 to 450 nm, when it is less than 400 nm, a high reflectance cannot be obtained when used as a reflector, and when it is larger than 450 nm, coloration due to absorption of visible light may not be obtained. White reflective film. When the emission wavelength is not in the range of 500 to 600 nm, when the reflection plate is used as a liquid crystal display device, when the reflection plate is not used, the effect of improving the reflectance cannot be obtained, and the effect of improving the brightness of the phosphor cannot be obtained.

The phosphor of the present invention may be an inorganic phosphor formed of an inorganic substance or an organic phosphor formed of an organic substance. The phosphor of the present invention must be stably fluorescently emitted after a long period of time, and must not be deteriorated or decomposed by ultraviolet rays. When the phosphor is deteriorated or decomposed, the film may turn yellow. When the reflector is used as a liquid crystal display device, color reproduction cannot be performed accurately. Further, when the phosphor is deteriorated or decomposed, the phosphor does not emit light, and when the reflector is used as a liquid crystal display device, the luminance may be lowered due to the phosphor. Therefore, the phosphor of the present invention is preferably an inorganic phosphor which is less likely to cause deterioration or decomposition of the organic phosphor and which is stable.

An inorganic phosphor having a rock salt type crystal structure, such as zinc sulfide (ZnS), antimony sulfide (SrS), or antimony oxide (Y ₂ O), may be used as the inorganic phosphor for the above-mentioned excitation wavelength and emission wavelength. ₂ ) is a precursor and contains uranium (Eu) or copper (Cu) as an activator. Further, a phosphor containing uranium (Eu) or manganese (Mn) as an activator may be used as a matrix of 钡 镁 ‧ aluminum composite oxide (Ba ₃ MgAl ₁₀ O ₁₇ ). Further, a phosphor having lanthanum phosphate (LaPO ₄ ) as a precursor and containing Ce and Tb as an activator can be used.

For the commercially available product of the inorganic phosphor, for example, a green light-emitting inorganic phosphor 2210 (manufactured by Kasei Optonix Co., Ltd., ZnS as a parent, Cu as an active material), and a red inorganic phosphor D1110 (a fundamental special chemical ( Stock system, Y ₂ O ₃ as the parent body, Eu as the active material), blue inorganic phosphor D1230 (manufactured by the special chemical (stock), with SrS as the parent and Eu as the active material) The green inorganic phosphor KX732A (manufactured by Kasei Optonix Co., Ltd., which is formed of 钡 镁 ‧ ‧ aluminum composite oxide (Ba ₃ MgAl ₁₀ O ₁₇ ) as the precursor and Eu or Mn as the active material).

An organic phosphor that satisfies the requirements of the excitation wavelength and the emission wavelength, for example, a lanthanum-based phosphor, a dioxon-based fluorescer, a benzoxazole-based fluorescer, or a styryl- oxazolyl-based fluorescing agent can be used. Agent, pyran-oxazole-based fluorescent agent, coumarin-based fluorescent agent, imidazole-based fluorescent agent, benzimidazole-based fluorescent agent, pyrazoline-based fluorescent agent, amine-based coumarin-based fluorescent agent A stilbene-biphenyl-based fluorescent agent or a naphthylimine-based fluorescent agent. Among these, benzoxazole-based fluorescent agents, styryl-oxazolyl-based fluorescent agents, and naphthoquinone-based fluorescent agents are more excellent in durability and high improvement in reflectance. Preferably, in particular, Eastbrite OB-1 (benzoxazole-based fluorescent agent manufactured by Eastman Co., Ltd.), Uvitex-OB (styrene-based oxazolyl-based fluorescent agent manufactured by Ciba-Geigy Co., Ltd.), and Lumogen green 850 are used. (Naphthylimine-based fluorescent agent manufactured by BASF Corporation) is preferred.

Light reflectance and chromaticity

When the light reflectance of the reflective film for an illumination device of the present invention does not contain a fluorescent material in the adhesive composition of the coating film, the light having a wavelength of 550 nm is preferably 96% or more. By having a reflectance of 96% or more, high luminance can be obtained.

In the reflective film for an illumination device of the present invention, when the fluorescent material is contained in the adhesive composition of the coating film, the chromaticity of the XYZ color system measured by the C light source is x=0.290 to 0.330, y=0.300 to 0.340. Preferably. By the chromaticity of the range, a reflector for an illuminating device containing a phosphor and having excellent color reproducibility, in particular, a reflector for a liquid crystal display device can be obtained.

UV absorber

The binder composition of the coating film is preferably a UV absorber in order to prevent deterioration by ultraviolet rays. The ultraviolet absorber of the present invention is a substance having an ultraviolet absorbing ability. The material may be an organic compound or an inorganic compound; in the case of an organic compound, for example, a benzophenone-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, a triazine-based ultraviolet absorber, and a cyanoacrylate-based ultraviolet absorber. Agent, salicylic acid-based ultraviolet absorber, benzoate-based ultraviolet absorber, oxalic acid anilide-based ultraviolet absorber. In the case of an inorganic compound, for example, a methyl hydrazide modification of an alkylamine carbaryl adduct of an alkoxycarbenyl group or an alkyl fluorenyl decyl group, or 2,4-dihydroxydiphenyl can be used. A methyl iodide-modified ultraviolet absorber containing a hydroxyl group and an epoxy group of an epoxy group-containing decane compound of an aromatic ultraviolet absorber such as a ketone.

When the binder composition of the coating film contains an ultraviolet absorber, the content thereof may be such an amount as to prevent deterioration of the organic phosphor, and therefore contains a necessary amount of the ultraviolet absorber. When the amount is such that the ultraviolet absorber is a low molecular weight, it is preferably from 1 to 15% by weight, more preferably from 2 to 5% by weight, based on the weight of the binder composition. By including this range, it is possible to effectively prevent the organic phosphor from being deteriorated by ultraviolet rays, and a coating film having no coloration can be obtained.

A polymer type can also be used as the ultraviolet absorber. At this time, for example, a copolymerized polymer in which a monomer component having a substituent having an ultraviolet absorbing ability is copolymerized with another monomer component can be used. The copolymerized polymer is preferably, for example, a polymer obtained by copolymerizing a benzotriazole-based reactive monomer with an acrylic monomer.

When the ultraviolet absorber is a polymer type, the copolymerization amount of the monomer having a substituent having an ultraviolet absorbing ability is preferably 10% by weight or more based on the total amount of all monomers constituting the copolymerized polymer. More preferably, it is 20% by weight or more, and the most preferred is 35% by weight or more. Of course, it may also be a homopolymer of a monomer having a substituent having ultraviolet absorbing ability. When it is less than 10% by weight, it is impossible to prevent deterioration of the organic fluorescent material due to ultraviolet rays. In the case of producing a strong coating film, the molecular weight of the copolymerized polymer is preferably 5,000 or more, more preferably 10,000 or more, and most preferably 20,000 or more. These copolymerized polymers can be used as a coating liquid in a state of being dissolved or dispersed in an organic solvent or water. In addition, as a commercially available hybrid ultraviolet absorbing polymer, for example, UWR (manufactured by Nippon Shokubai Co., Ltd.) can be used as the ultraviolet absorbing agent.

Light stabilizer

In the binder composition of the coating film, in addition to the ultraviolet absorber, a light stabilizer can be used in combination, and it is preferable to obtain excellent durability. In this case, the amount of the light stabilizer is, for example, 0.1 to 5% by weight, preferably 0.5 to 3% by weight based on the weight of the binder composition.

The light stabilizer is preferably a hindered amine light stabilizer. Specifically, for example, bis(2,2,6,6-tetramethyl-4-piperidyl) phthalate or dimethyl succinate ‧1-(2-hydroxyethyl)-4-hydroxy-2 can be used. 2,6,6-Tetramethylpiperidine polycondensate.

In the following, it will be explained in detail by way of examples. Further, the measurement and evaluation were carried out in the following manner.

[Examples]

(1) Relative brightness

The brightness of the display device when used as a reflector in a liquid crystal display device was evaluated. Remove the reflective film of the backlight of the 32-inch TV (Bravia KDL-32V2500) made by Sony, and set the film to replace the evaluation object. Use a luminance meter (Model MC-940 from Otsuka Electronics Co., Ltd.) to make the center of the backlight from the front. The brightness was measured at a distance of 500 mm. The relative brightness was obtained by the following formula.

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

The film used as the reference film differs depending on the table described in the evaluation results. The following film was used as the reference film.

Table 1: Film of Comparative Example 1-1 in which no transparent protrusions were provided.

Table 2: Film of Comparative Example 2-1 in which no protrusions made of transparent particles were provided.

Table 3: Film of Comparative Example 3-1 in which no protrusions made of transparent particles were provided.

Table 4: Film of Reference Example 1-1 containing no phosphor in the adhesive of the coating film.

Table 5: Film of Comparative Example 5-1 in which no protrusions made of transparent particles were provided.

(2) transparent protrusion

(2-1) Coverage ratio of film formed by transparent protrusions

Using a film slicer, a slice was cut into a cut surface in the thickness direction of the film as a sample. The sliced sample was observed at a magnification of 3000 times using an S-4700 electric field discharge scanning electron microscope manufactured by Hitachi. The measurement range in which the total length of the measurement range of 3 mm in each of the two perpendicular directions in the film surface was 6 mm was observed, and the length of the portion which was not covered by the transparent projection was accumulated in the measurement range, and was obtained by the following formula.

Coverage ratio = (6 mm - (cumulative length (mm) of the portion not covered with transparent particles)) / 6 mm × 100 (%)

(2-2) Height of transparent protrusion

With respect to the surface of the film as a reference surface, the height of the apex is measured with respect to 20 arbitrary transparent protrusions, and the average value is used as the height of the transparent protrusion. Further, the transparent protrusions are formed of transparent particles, and when the transparent particles are buried in the binder, the surface of the binder is used as a reference surface. For the measurement of the height, a sliced sample was cut out from the film using a microtome, and the sample was observed and photographed at 300 times using an optical microscope.

(3) forming transparent particles of protrusions

(3-1) Average particle size of transparent particles

The particles before the addition of the resin (raw material) were measured at a magnification of 1000 times using an S-4700 electric field discharge scanning electron microscope manufactured by Hitachi, Ltd., and the average particle diameter was determined. When the particles are not spherical, (long diameter + short diameter) / 2 is used as the average particle diameter.

(3-2) Aspect ratio of transparent particles

An arbitrary number of the exposed particles were observed at a magnification of 500 times using an S-4700 electric field discharge scanning electron microscope manufactured by Hitachi, Ltd., and the average value obtained by the following formula was calculated from the long diameter and the short diameter.

Aspect ratio = long diameter / short diameter

(3-3) D50 of transparent particles

The particle size distribution of the transparent particles of the raw material was determined by a particle size distribution meter (LA-950, manufactured by Horiba, Ltd.) to form a particle diameter of 50% by weight of the cumulative percentage of the sieves of D50.

(3-4) D10/D90 of transparent particles

The particle size distribution of the transparent particles of the raw material was determined by a particle size distribution meter (LA-950, manufactured by Horiba, Ltd.) to form a particle size of 10% by weight of the sieve, and the particle size was D10 to form a cumulative percentage of the sieve. The particle size of % is D90, and D10/D90 is obtained.

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

The average particle diameter of the inorganic particles and the organic particles of the white film was determined by the particle size distribution (LA-950, manufactured by Horiba, Ltd.), and the particle size distribution of the particles of the raw material was determined, and the particle diameter of d50 was defined as the average particle diameter.

(5) Thickness of coating film

The cross section of the film sample was observed by a digital microscope (HIROX Co. Ltd., HI-SCOPE Advanced KH-3000) at a magnification of 5 times, and the thickness of the adhesive was judged from the photograph, and an arbitrary 10 points were measured. The average of the values.

(6) Thickness of the film

(6-1) Thickness of film

The film sample was measured by an electron microscope measuring instrument (K-402B manufactured by Anritsu Co., Ltd.) at a thickness of 10 points, and the average value was used as the thickness of the film.

(6-2) Thickness of each layer of the film

The sample was cut into triangles, fixed in an embedding capsule, and embedded in epoxy resin. Then, the embedded sample was sliced in a longitudinal direction by a slicer (ULTRACUT-S) to form a parallel cross section, and then observed and photographed using an optical microscope, and the thickness ratio of each layer was measured from the photograph, and the thickness was calculated from the thickness of the entire film. , to determine the thickness of each layer.

(7) Exposure rate of transparent particles

The sliced sample 1 and the sliced sample 2 were cut out from the film using a sheet slicer. The sliced sample 1 is arbitrarily selected in one direction on the inner surface of the film, and a sliced sample cut out under the cut surface in the thickness direction of the film; the sliced sample 2 is arbitrarily selected and one direction in the sliced sample 1. The vertical direction and the sliced sample cut out under the cut surface in the thickness direction of the film.

The measurement range of the range of 3 mm in length of the coating film surface of the adhesive of the sliced sample 1 and the total length of the coating film surface of the sliced sample 2 in the range of 3 mm was 6 mm, and the S-made by Hitachi, Ltd. was used. The 4700-shaped electric field emission scanning electron microscope was observed at a magnification of 3000 times.

The exposure rate is obtained by passing the line perpendicular to the coating film surface of the film through the center of the cross section of the transparent particle in the cut surface of the sliced sample, and the straight line intersects the surface of the transparent particle in the cut surface of the film slice. In the two points, the point on the surface on the exposed side is S, and the point on the surface on the unexposed side is T. When the point where the straight line intersects the coating surface of the adhesive is B, (between S and B) The distance) / (distance between S and T) is expressed.

In other words, the exposure rate (%) is defined by the following formula.

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

Further, when the center of the cross section of the transparent particles in the plane is cut, when the particles are spherical, the center of the circle is the cross section; and when the particles are non-spherical, the center of gravity of the cross section.

(8) Coverage ratio of transparent particles on the surface of the film

The evaluation was carried out on the sliced samples 1 and 2 obtained in the above (7).

The measurement range of the length of the coating film surface of the adhesive sample of the sliced sample 1 of 3 mm and the total length of the coating film surface of the sliced sample 2 of 3 mm was 6 mm, and the S-made by Hitachi, Ltd. was used. A 4700-shaped electric field emission scanning electron microscope was observed at a magnification of 3000 times.

The coverage ratio is obtained within the measurement range of the cut surface of the sliced sample, and the length of the portion of the surface of the film which is not covered with the transparent particles is obtained by the following formula (see Fig. 1).

Coverage ratio = (6 mm - (cumulative length of the portion not covered by the transparent particles (mm))) / 6 mm × 100 (%)

(9) Extensibility

When the film was produced by stretching 2.5 to 3.4 times in the longitudinal direction and 3.5 to 3.7 times in the longitudinal direction, it was observed whether or not the film formation was stable, and the evaluation was performed based on the following criteria.

○: Film formation can be carried out stably for more than 1 hour

×: The cutting occurred within 1 hour, and the film could not be stably formed.

(10) Yellowing over time

A high-pressure mercury lamp ("Toscure 401" by Harrison Toshiba Lighting: glass filter) was irradiated on the sample of the film to evaluate the color change of the sample. The irradiation time for this evaluation was 50 hours, and the color change before and after the irradiation was evaluated. The illuminance of the irradiation was 18 mW/cm ² . Further, when the film is formed such that a reflective layer is provided on one side of the support layer, the measurement is performed from the side of the reflective layer.

The initial film hue (L ₁ *, a ₁ *, b ₁ *) and the film hue after irradiation (L ₂ *, a ₂ *) were measured by a color difference meter (SZS-Σ90 COLOR MEAEURING SYSTEM, manufactured by Nippon Denshoku Industries Co., Ltd.). , b ₂ *), and the hue change dE* shown by the following formula was calculated and evaluated on the basis of the following criteria.

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

◎: dE*≦5

○: 5<dE*≦10

△: 10<dE*≦15

×: 15<dE*

(11) Is there excitation excitation and luminescence peak wavelength by light of 400 to 500 nm?

Light was incident on the surface on which the phosphor was applied, and the fluorescence spectrum was measured. In the measurement, a fluorescence photometer F-4500 (manufactured by Hitachi Ltd.) was used, and the excitation wavelength was 400 to 450 nm, and the emission wavelength was 380 to 780 nm. When there was a fluorescent light emission by excitation, when there was a fluorescent light emission, The wavelength of the luminescence peak from the luminescence spectrum is obtained.

(12) Is there any particle shedding?

An acrylic plate having a right-angled side having a thickness of 2 mm and a width of 20 mm was vertically attached to the reflecting surface of the film sample at a load of 300 g, and was fed back and forth 10 times at a distance of 30 mm. It was visually confirmed whether or not powder adhered to the acrylic plate at this time, and it was evaluated based on the following criteria.

○: Confirm that almost no powder is produced

×: It can be confirmed that powder is produced.

(13) Brightness improvement rate and brightness maintenance rate

(13-1) Brightness improvement rate as a reflection plate

The film is assembled in the backlight for measurement and evaluation. The backlight used is a direct-type backlight (diagonal 20 吋) unit used for evaluation of a liquid crystal television (AQUOS-20V manufactured by SHARP), and a film to be measured is assembled in place of the originally assembled light-reflecting sheet. The measurement was performed by dividing the backlight surface into four regions of 2 × 2, and performing the front luminance after one hour of lighting.

The brightness was measured using BM-7 manufactured by Topcon Corporation. The measurement angle is 1°, and the distance between the luminance meter and the backlight is 50 cm. The backlight surface is divided into four lines passing through a center of the backlight surface and parallel to the width direction of the backlight surface, and a line passing through the center of the backlight surface and parallel to the longitudinal direction of the backlight surface, and the center of each divided range is Measuring point.

The brightness of the four measurement points was measured for each and a simple average value was obtained as the average brightness. The brightness improvement rate is calculated by the following formula using the average brightness obtained by the film before and after coating with the fluorescent material.

Brightness improvement rate = (average brightness after coating of fluorescent material) / (average brightness before coating of fluorescent material) × 100 (%)

(13-2) Brightness maintenance rate by durability test

In the state in which the film to be evaluated was assembled, a durability test in which the above-described backlight was subjected to lighting for 3,000 hours was performed. The brightness maintenance ratio was obtained by the following formula.

Brightness maintenance rate = (average brightness after durability test) / (brightness before durability test) × 100 (%)

(14) Chroma

(14-1) Difference in chromaticity as a reflector

The backlight assembled with the film was measured and evaluated. The backlight used is a direct-type backlight (diagonal 20 吋) unit used for evaluation of a liquid crystal television (AQUOS-20V manufactured by SHARP), and the measurement object is assembled instead of the originally assembled light-reflecting sheet. film. The measurement was performed by dividing the backlight surface into four regions of 2 × 2, and performing the front luminance after one hour of lighting.

The chromaticity was measured using BM-7 manufactured by Topcon Corporation. The measurement angle is 1°, and the distance between the luminance meter and the backlight is 50 cm. The backlight surface is divided into four lines passing through a center of the backlight surface and parallel to the width direction of the backlight surface, and a line passing through the center of the backlight surface and parallel to the longitudinal direction of the backlight surface, and the center of each divided range is Measuring point.

The chromaticity (x, y) of each of the four measurement points was measured, and a simple average value was obtained as the average chromaticity (x, y). The distance between the average chromaticity (x, y) and the reference color (x = 0.300, y = 0.310) is obtained, and the chromaticity difference Δxy is obtained.

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

△ y = reference coordinate (y = 0.310) - measured coordinates (y)

^{△ xy = (△ x 2 +} △ y 2) 1/2

The obtained Δxy was evaluated on the basis of the following criteria.

◎: △xy<0.005

○: 0.005 ≦ Δxy <0.010

×: 0.010 ≦ Δxy

(14-2) Chromaticity difference by durability test

In the state in which the film to be evaluated was assembled, a durability test of the above-described backlight lighting for 3,000 hours was performed. The distance between the average chromaticity (x, y) before the durability test and the average chromaticity (x, y) after the durability test was determined by the following formula and evaluated.

△x=pre-durability test front coordinate (x)-posteriority test (x)

△ y = durability test front coordinate (y) - durability test post coordinate (y)

^{△ xy = (△ x 2 +} △ y 2) 1/2

The obtained Δxy was evaluated on the basis of the following criteria.

:△xy<0.005

○: 0.005 ≦ Δxy <0.010

×: 0.010 ≦ Δxy

(14-3) Chroma by C source

The measurement was performed using a C light source using a color difference meter (SZS-Σ90 COLOR MEAEURING SYSTEM, manufactured by Nippon Electric Co., Ltd.).

(15) Light reflectance

An integrating sphere was placed in a spectrophotometer (UV-3101PC manufactured by Shimadzu Corporation), and the light reflectance at a wavelength of 550 nm when the BaSO ₄ whiteboard was 100% was measured.

(16) Coating composition and white film

The composition of the coating film is as follows. In the table, "% by weight" is described as "wt%".

<Transparent particles ‧ Protrusion forming substances>

MBX-50SS: Transparent acrylic particles with an average particle size of 50 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-30SS: Transparent acrylic acid particles with an average particle size of 30 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-20SS: Transparent acrylic acid particles with an average particle size of 20 μm made by Sekisui Chemicals Co., Ltd.

MBX-15SS: Transparent acrylic acid particles with an average particle size of 15 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-12SS: Transparent acrylic acid particles with an average particle size of 12 μm made by Sekisui Chemicals Co., Ltd.

MBX-10SS: Transparent acrylic acid particles with an average particle size of 10 μm made by Sekisui Chemicals Co., Ltd.

MBX-50: Transparent acrylic particles with an average particle size of 50 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-30: Transparent acrylic acid particles with an average particle size of 30 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-20: Transparent acrylic acid particles with an average particle size of 20 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-15: Transparent acrylic acid particles with an average particle size of 15 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-12: Transparent acrylic acid particles with an average particle size of 12 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-8: Transparent acrylic acid particles with an average particle size of 8 μm manufactured by Sekisui Chemicals Co., Ltd.

MBX-5: Transparent acrylic acid particles with an average particle size of 5 μm manufactured by Sekisui Chemicals Co., Ltd.

J-120: Transparent glass particles with an average particle size of 105 μm manufactured by Potters-Ballotini

MX-1000: Transparent acrylic particles with an average particle size of 10 μm made by Xiayan Chemical Co., Ltd.

MX-150: Transparent acrylic particles with an average particle size of 2 μm made by Xiayan Chemical Co., Ltd.

MR-20G: Transparent crosslinked acrylic particles with an average particle size of 20 μm made by Xiayan Chemical Co., Ltd.

MR-10G: Transparent crosslinked acrylic particles with an average particle size of 10 μm made by Xiayan Chemical Co., Ltd.

<Binder>

S2740: UWR S2740 made by Nippon Shokubai Co., Ltd.

Acrylic adhesive formed by 50% by weight of solid component acrylic resin and 50% by weight of volatile organic solvent

A807BA: Acrydic A807BA made by DIC

Acrylic adhesive formed by 50% by weight of solid component acrylic resin and 50% by weight of volatile organic solvent

<crosslinker>

HL: Japanese Polyurethane Industry Company Coronate HL

a crosslinking agent formed by a solid component crosslinking agent of 75% by weight and a volatile organic solvent of 25% by weight

<fluorescent matter>

OB-1: Eastbrite OB-1 by Eastman

Green850: Lumogen Green 850 made by BASF

Uvitex-OB: Uvitex-OB, manufactured by Ciba-Geigy

<solvent>

MEK: methyl ethyl ketone

In the examples and the comparative examples, a total of a total of two layers of a reflective layer formed of a polyester composition containing barium sulfate particles containing a void-forming agent and a support layer formed of a polyester is used. A white film having a thickness of 225 μm (reflectance of 98.5% of the reflection layer of Teijintex UX02-225 made by Teijin Dupont film) was used as a white film.

Example 1-1

On the reflective layer of the white film, the coating liquid formed by the composition shown in the following liquid preparation formula was applied in a coating application apparatus at a coating thickness of 20 g/m ² in a mold coating apparatus, and then carried out in an oven. Drying to produce a reflective film.

Liquid adjustment formula 1-1)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-20SS (38% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (20% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Example 1-2

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 10 g/m ² of wet thickness. A reflective film is obtained.

Liquid adjustment formula 1-2)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-10SS (30% by weight)

‧Acrylic adhesive: U.S. catalyst company UWRS2740 (28% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: ethyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Examples 1-3

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 25 g/m ² of wet thickness. A reflective film is obtained.

Liquid adjustment formula 1-3)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-30SS (32% by weight)

‧Acrylic adhesive: DIC company Acrydic A807BA (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: methyl ethyl ketone (40% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Examples 1-4

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 30 g/m ² of wet thickness. A reflective film is obtained.

Liquid adjustment formula 1-4)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-50SS (25% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (38% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: ethyl acetate (34% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Examples 1-5

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 15 g/m ² of wet thickness. A reflective film is obtained.

Liquid adjustment formula 1-5)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-15SS (19% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (37% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (4% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Example 1-6

A quadrangular pyramid-shaped projection is formed on the entire reflective layer of the white film without any void at all. In other words, the coating liquid formed by the composition shown in the liquid preparation formulation described below was poured into a SUS mold having a quadrangular pyramid shape, and a white film was adhered thereto, and UV was irradiated with a high pressure mercury lamp (Toscure manufactured by Harrsion Toshiba Lighting). Light, the coating liquid was hardened, dried in an oven at 100 ° C, and a quadrangular pyramid was formed on the reflective surface of the white film to obtain a reflective film. The size of the reflective film is in accordance with the size of the reflective film of the backlight of the 32-inch TV (Bravia KDL-32V2500) made by Sony. A typical view of the quadrangular pyramid portion of the mold used to form the quadrangular pyramid type projection is shown in Fig. 1.

Liquid conditioning formula 1-6) UV curing resin

‧Daicel UC EB3700

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

‧Xinzhongcun Chemical Company BPE200

(ethylene oxide addition bisphenol A methacrylate) (8% by weight)

‧The first pharmaceutical industry company BR-31

(Phenoxyethyl tribromide acrylate) (42% by weight) ‧ East Asia Synthesis Company M-110

((meth)acrylate of p- cumenylphenol reacted with ethylene oxide) (8% by weight)

‧BASF made LR8893 (free 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, the coating liquid of the composition of the liquid preparation formula 6 of Example 1-6 was applied to the mold coating apparatus at a coating amount of wet 15 g/m ² , and then applied to the coated surface of the film. The roll having the ridge-like unevenness as shown in Fig. 2 is cured by a high-pressure mercury lamp (Toscure manufactured by Harrsion Toshiba Lighting) in a state where irregularities are formed on the coating layer, and is carried out in an oven at 100 ° C. Dry and make a crucible shape.

Further, in the measurement of the relative luminance of this embodiment, a reflective film was provided in parallel with the flow direction of the crucible in parallel with the cold cathode tube of the light source of the backlight.

The evaluation results are shown in Table 1-3.

Example 1-8

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 15 g/m ² of wet thickness. A reflective film is obtained.

Liquid adjustment formula 1-8)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-20SS (38% by weight)

‧Acrylic adhesive: Japanese catalyst company UWRS2740 (20% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Fluorescent material: Eastman company Eastbrit OB-1 (3.4% by weight)

‧Organic solvent: butyl acetate (36.6 wt%)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Example 1-9

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 15 g/m ² of wet thickness. A reflective film is obtained.

Liquid adjustment formula 1-9)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-20SS (38% by weight)

‧Acrylic adhesive: Japanese catalyst company UWRS2740 (20% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Fluorescent material: BASF Lumogen Green 850 (2.3% by weight)

‧Organic solvent: butyl acetate (37.7 wt%)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Examples 1-10

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 15 g/m ² of wet thickness. A reflective film is obtained.

Liquid adjustment formula 1-10)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-20SS (38% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (20% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Fluorescent material: Ciba-Geigy Uvitex-OB (2.3% by weight)

‧Organic solvent: butyl acetate (37.7 wt%)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Comparative Example 1-1

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

Comparative Example 1-2

Except that the coating liquid to the coating liquid by a liquid having the composition shown in the following formula is formed, and with wet thickness of 40g / m ² coating amount of the outer coating, in the same manner as in Example 1-1, was prepared Reflective film.

Liquid adjustment formula 1-7)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (57% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Comparative Example 1-3

The same procedure as in Example 1-1 was carried out except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 2 g/m ² of wet thickness. Reflective film.

Liquid adjustment formula 1-8)

‧ Protrusion forming substance: Comprehensive research chemical company MX-150 (30% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (27% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Comparative Example 1-4

It was produced in the same manner as in Example 1-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of wet thickness of 80 g/m ² . Reflective film.

Liquid adjustment formula 1-8)

‧ Prominent material: Potters-Ballotini J-120 (30% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (27% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Comparative Example 1-5

It was produced in the same manner as in Example 1-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 40 g/m ² of wet thickness. Reflective film.

Liquid adjustment formula 1-9)

‧ Protrusion forming material: Sekisui Chemicals Industrial Co., Ltd. MBX-50 (3 wt%)

‧Acrylic adhesive: DIC company Acrydic A807BA (50% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (44% by weight)

The composition of the obtained reflective film is shown in Table 1-2, and the evaluation results are shown in Table 1-3.

Comparative Example 1-6

A reflective film provided with a crucible on the reflective layer was produced in the same manner as in Example 1-6, except that the shape of the crucible provided on the reflective layer of the white film was changed to the shape shown in Fig. 3. The evaluation results are shown in Table 1-3.

Comparative Example 1-7

A surface-processed film was produced in the same manner as in Example 1-7 except that the shape of the crucible provided on the reflective layer of the white film was changed to the shape shown in Fig. 4. The evaluation results are shown in Table 1-3.

Example 2-1

The coating liquid formed of the composition shown in the following liquid preparation formula was applied to a white film on a white coating film at a coating thickness of 25 g/m ² in a mold coating apparatus, and then dried in an oven. A reflective film is obtained.

Liquid adjustment formula 2-1)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-30SS (35 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (23% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Example 2-2

The coating liquid was changed to the coating liquid having the composition shown by the following liquid preparation formula, and coated with a coating thickness of 12 g/m ² of wet thickness, and the same as in Example 2-1. Reflective film.

Liquid adjustment formula 2-2)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15SS (35 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (23% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Example 2-3

The coating liquid was changed to the coating liquid having the composition shown by the following liquid preparation formula, and coated with a coating thickness of 40 g/m ² of wet thickness, and the same manner as in Example 2-1 was carried out. Reflective film.

Liquid adjustment formula 2-3)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-50SS (32% by weight)

‧Acrylic adhesive: DIC company Acrydic A807BA (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Example 2-4

The coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 10 g/m ² of wet thickness, and the same as in Example 2-1. Reflective film.

Liquid adjustment formula 2-4)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-12SS (38% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: ethyl acetate (34% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Example 2-5

The coating liquid was changed to the coating liquid having the composition shown by the following liquid preparation formula, and coated with a coating thickness of 7 g/m ² of wet thickness, and the same manner as in Example 2-1 was carried out. Reflective film.

Liquid adjustment formula 2-5)

‧Transparent particles: Sekisui finished product company MBX-10SS (19% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (37% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (4% by weight)

‧Organic solvent: ethyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Example 2-6

The coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 8 g/m ² of wet thickness, and the same manner as in Example 2-1 was carried out. Reflective film.

Liquid adjustment formula 2-6)

‧Transparent Particles: Comprehensive Research Chemical Company MX-1000 (40% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: methyl ethyl ketone (33% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Comparative Example 2-1

The evaluation film was carried out without applying a coating liquid on a white film. The evaluation results are shown in Table 2-3.

Comparative Example 2-2

The coating liquid was changed to the coating liquid having the composition shown by the following liquid preparation formula, and coated with a coating thickness of 40 g/m ² of wet thickness, and the same manner as in Example 2-1 was carried out. Reflective film.

Liquid adjustment formula 2-7)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (57% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Comparative Example 2-3

The coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 2 g/m ² of wet thickness, and the same as in Example 2-1. Reflective film.

Liquid adjustment formula 2-8)

‧Particles: Comprehensive Research Chemical Company MX-150 (30% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (27% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Comparative Example 2-4

The coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 80 g/m ² of wet thickness, and the same as in Example 2-1. Reflective film.

Liquid adjustment formula 2-9)

‧Particles: Potters-Ballotini J-120 (30% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (27% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Comparative Example 2-5

The coating liquid was changed to the coating liquid having the composition shown by the following liquid preparation formula, and coated with a coating thickness of 40 g/m ² of wet thickness, and the same manner as in Example 2-1 was carried out. Reflective film.

Liquid adjustment formula 2-10)

‧Particles: Sekisui Chemicals Industrial Co., Ltd. MBX-50 (3 wt%)

‧Acrylic adhesive: DIC company Acrydic A807BA (50% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (44% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Comparative Example 2-6

The coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formula, and coated with a coating thickness of 8 g/m ² of wet thickness, and the same manner as in Example 2-1 was carried out. Reflective film.

Liquid adjustment formula 2-11)

‧Particles: Sekisui Chemicals Industrial Co., Ltd. MBX-8 (1% by weight)

‧Acrylic adhesive: DIC company Acrydic A807BA (56% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 2-2, and the evaluation results are shown in Table 2-3.

Example 3-1

132 parts by weight of dimethyl terephthalate, 18 parts by weight of dimethyl isophthalate (12 mol% based on the entire dicarboxylic acid component of the polyester), 98 parts by weight of ethylene glycol, and 2 1.0 part by weight of diethanol, 0.05 parts by weight of manganese acetate, and 0.012 parts by weight of lithium acetate were placed in a flask equipped with a rectification column and a distillation condenser, and heated at 150 to 235 ° C while stirring to distill off methanol for transesterification. reaction. After distilling off methanol, 0.03 part by weight of trimethyl phosphate and 0.04 parts by weight of cerium oxide were added, and the reactant was transferred to a reactor. Then, the inside of the reactor was gradually reduced to 0.5 mmHg while stirring, and the temperature was raised to 290 ° C to carry out a polycondensation reaction to obtain a polyester. To the polyester, barium sulfate particles having an average particle diameter of 1.2 μm were added to obtain a polyester composition for a support layer containing 4% by weight of barium sulfate particles. Barium sulfate particles and phosphors having an average particle diameter of 1.2 μm were added to the same polyester to obtain a white reflection containing 47% by weight of barium sulfate particles and 5.5% by weight of green light-emitting inorganic phosphor KX732A (Kasei Optonix) The layer is composed of a polyester composition.

Using these polyester compositions, they were supplied to two extruders heated at 270 ° C, and the polyester composition for the support layer and the polyester composition for the white reflective layer were composed of a layer of a reflective layer/support layer. The two-layer packing zone device is joined to form a sheet-like shape while being maintained in the laminated state. Further, the unstretched film in which the sheet was cooled and hardened by a cooling barrel having a surface temperature of 25 ° C was extended 2.9 times in the longitudinal direction (longitudinal direction) in an environment of heating at 95 ° C, and was cooled at a roll group of 25 ° C. Then, both ends of the longitudinally stretched film were held by a clip and introduced into a tenter, and extended 3.6 times in a direction perpendicular to the longitudinal direction (width direction) in an environment of heating at 120 °C. Thereafter, the film was heat-fixed in a tenter at a temperature of 215 ° C, and then relaxed by 0.5% in the longitudinal direction, relaxed by 2.0% in the transverse direction, and cooled to room temperature to obtain a film having a biaxially stretched laminate. White substrate film. The thickness of the white base film was 225 μm, and the reflectance of the reflective layer was 98.7%.

Next, the coating liquid manipulation bar coating apparatus consists of the following formulation was adjusted as shown is formed in the wet coating amount of 25g / m ² was coated on a white reflective layer side, then dried in an oven , a reflective film is produced. The particle size and aspect of the transparent particles are shown in Table 3-1.

Liquid adjustment formula 3-1)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-30 (35 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (23% by weight)

‧ Crosslinking agent: Coronate H (2% by weight) of Japan Polyurethane Industry Co., Ltd.

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are shown in Table 3-3.

Example 3-2

A reflective film was obtained in the same manner as in Example 3-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation.

Liquid adjustment formula 3-2)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15 (35 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (23% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are shown in Table 3-3.

Example 3-3

A reflective film was obtained in the same manner as in Example 3-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation.

Liquid adjustment formula 3-3)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-50 (32% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are shown in Table 3-3.

Example 3-4

A reflective film was obtained in the same manner as in Example 3-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation.

Liquid adjustment formula 3-4)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-12 (38% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: ethyl acetate (34% by weight)

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are shown in Table 3-3.

Example 3-5

A reflective film was obtained in the same manner as in Example 3-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation.

Liquid adjustment formula 3-5)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-5 (19% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (37% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (4% by weight)

‧Organic solvent: ethyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are 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% by weight of the green light-emitting inorganic phosphor 2210 (manufactured by Kasei Optonix Co., Ltd.).

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are 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% by weight of the organic fluorescent whitening agent OB-1 (manufactured by Eastman Co., Ltd.). .

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are shown in Table 3-3.

Comparative Example 3-1

A white base film was obtained in the same manner as in Example 3-1 except that the fluorescent material was not added to the white reflective layer of the white base film, and the evaluation was white without applying the coating liquid on the white base film. Substrate film. The evaluation results are shown in Table 3-3.

Comparative Example 3-3

The same procedure as in Example 3-2 was carried out except that the fluorescent material was not added to the white reflective layer of the white base film and the coating liquid was changed to the composition shown by the composition shown in the following liquid preparation formula. A reflective film is obtained.

Liquid adjustment formula 3-6)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15 (10% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (48% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are shown in Table 3-3. The case where the color does not match due to coloring is small, but the increase in brightness is small.

Comparative Example 3-4

The same procedure as in Example 3-2 was carried out except that the fluorescent material was not added to the white reflective layer of the white base film and the coating liquid was changed to the composition shown by the composition shown in the following liquid preparation formula. A reflective film is obtained.

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15 (2% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (56% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 3-2, and the evaluation results are shown in Table 3-3. The case where the color does not match due to coloring is small, but the increase in brightness is small.

Comparative Example 3-5

The white base film of Example 3-2 was evaluated in the state where the coating liquid was not applied to the white base film. The evaluation results are shown in Table 3-3. The case where the color does not match due to coloring is small, but the increase in brightness is small.

Comparative Example 3-6

The white base film of Example 3-6 was evaluated without coating the coating liquid on the white base film. The evaluation results are shown in Table 3-3. The case where the color does not match due to coloring is small, but the increase in brightness is small.

Comparative Example 3-7

The white base film of Evaluation Example 3-7 was evaluated in the state where the coating liquid was not applied to the white base film. The evaluation results are shown in Table 3-3. The case where the color does not match due to coloring is small, but the increase in brightness is small.

Comparative Example 3-8

A reflective film was obtained in the same manner as in Comparative Example 3-5 except that the amount of the green light-emitting inorganic phosphor KX732A added to the reflective layer of the white base film was changed to 17% by weight. The composition of the obtained reflective film coating film is shown in Table 3-2, and the evaluation results are shown in Table 3-3. Although the brightness rises greatly, the color does not match due to coloring, and it cannot be practical.

Comparative Example 3-9

A reflective film was obtained in the same manner as in Comparative Example 3-5 except that the amount of the green light-emitting inorganic phosphor 2210 added to the reflective layer of the white base film was changed to 8% by weight. The composition of the obtained reflective film coating film is shown in Table 3-2, and the evaluation results are shown in Table 3-3. Although the brightness rises greatly, the color does not match due to coloring, and it cannot be practical.

Example 4-1

In the mold coating apparatus, the coating liquid formed by the composition shown in the following liquid preparation formula is coated on the reflective layer of the white film with a thickness of 4 μm after drying, and then dried in an oven. , a reflective film is produced.

Liquid adjustment formula 4-1)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15SS (35 wt%)

‧Fluorescent material: Kasei Optonix KX-732A (10% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (23% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (30% by weight)

The composition of the obtained reflective film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.

Example 4-2

A reflective film was prepared in the same manner as in Example 4-1 except that the coating liquid was changed to a coating liquid composed of the composition shown in the following liquid preparation formulation, and the coating was applied to a thickness of 8 μm after drying.

Liquid adjustment formula 4-2)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-50SS (32% by weight)

‧Fluorescent material: Kasei Optonix RX-732A (10% by weight)

‧Acrylic adhesive: DIC company Acrydic A807BA (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (30% by weight)

The composition of the obtained reflective film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.

Example 4-3

A reflective film was obtained in the same manner as in Example 4-1 except that the coating liquid was changed to the coating liquid formed by the composition shown in the following formulation.

Liquid adjustment formula 4-3)

‧Transparent Particles: Comprehensive Research Chemical Company MX-1000 (40% by weight)

‧Fluorescent material: Kasei Optonix 2210 (5 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (25% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: methyl ethyl ketone (28% by weight)

The composition of the obtained reflective film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.

Reference example 4-1

A reflective film was obtained in the same manner as in Example 4-1 except that the coating liquid was changed to the coating liquid formed by the composition shown in the following formulation.

Liquid adjustment formula 4-4)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15SS (35 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (23% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (2% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.

Comparative Example 4-4

A reflective film was obtained in the same manner as in Example 4-1 except that the coating liquid was changed to the coating liquid formed by the composition shown in the following formulation.

Liquid adjustment formula 4-5)

‧Fluorescent material: Kasei Optonix KX-732A (10% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (57% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (30% by weight)

The composition of the obtained reflective film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.

Comparative Example 4-5

A reflective film was obtained in the same manner as in Example 4-1 except that the coating liquid was changed to the coating liquid formed by the composition shown in the following formulation.

Liquid adjustment formula 4-6)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15SS (3 wt%)

‧Fluorescent material: Kasei Optonix 2210 (5 wt%)

‧Acrylic adhesive: DIC company Acrydic A807BA (50% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (3 wt%)

‧Organic solvent: butyl acetate (39% by weight)

The composition of the obtained reflective film is shown in Table 4-2, and the evaluation results are shown in Table 4-3.

Comparative Example 4-6

The evaluation film was carried out without applying a coating liquid on a white film. The evaluation results are shown in Table 4-3.

Example 5-1

In the mold coating apparatus, on the reflective layer of the white film, the coating liquid formed by the composition shown in the following liquid preparation formula is applied to the thickness of the adhesive after drying to a thickness of 8 μm, and then dried in an oven. , a reflective film is produced.

Liquid adjustment formula 5-1)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-12 (35 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (21% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (4% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.

Example 5-2

A reflective film was prepared in the same manner as in Example 5-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation, and the thickness of the adhesive after drying was 10 μm.

Liquid adjustment formula 5-2)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-15 (35 wt%)

‧Acrylic adhesive: DIC company Acrydic A807BA (21% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (4% by weight)

‧Organic solvent: methyl ethyl ketone (40% by weight)

The composition of the obtained reflective film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.

Example 5-3

A reflective film was prepared in the same manner as in Example 5-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation, and the thickness of the adhesive after drying was 14 μm.

Liquid adjustment formula 5-3)

‧Transparent particles: Sekisui Chemicals Industrial Co., Ltd. MBX-20 (35 wt%)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (21% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (4% by weight)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.

Comparative Example 5-1

The evaluation film was not evaluated after the coating liquid was applied on the white film. The evaluation results are shown in Table 5-3.

Comparative Example 5-3

A reflective film was prepared in the same manner as in Example 5-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation, and the thickness of the binder after drying was 6 μm.

Liquid adjustment formula 5-4)

‧Transparent Particles: Comprehensive Research Chemical Company MR-10G (15% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (37% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (8 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.

Comparative Example 5-5

A reflective film was prepared in the same manner as in Example 5-1 except that the coating liquid was changed to the coating liquid formed of the composition shown in the following liquid preparation formulation, and the thickness of the adhesive after drying was 14 μm.

Liquid adjustment formula 5-5)

‧Transparent particles: Comprehensive research chemical company MR-20G (15% by weight)

‧Acrylic adhesive: U.S. catalyst company UWR S2740 (37% by weight)

‧ Crosslinking agent: Japan Polyurethane Industry Co. Coronate HL (8 wt%)

‧Organic solvent: butyl acetate (40% by weight)

The composition of the obtained reflective film is shown in Table 5-2, and the evaluation results are shown in Table 5-3.

[Industry use value]

In the reflective film for a lighting device of the present invention, a reflecting plate as a lighting device can be used, and a reflective film as a backlight unit of a liquid crystal display device can be suitably used, and in particular, a backlight of a light source such as a liquid crystal television is provided with a backlight. A reflective film used in a backlight unit of a liquid crystal display device.

Fig. 1 is a schematic view showing a quadrangular pyramid portion of a mold used in the formation of a quadrangular pyramid projection in Examples 1-6.

Fig. 2 is a plan view showing a ridge-like uneven shape formed on the coating layer when the unevenness is formed on the coating layer by using a roll having a meandering unevenness in the first embodiment.

Fig. 3 is a schematic view showing a quadrangular pyramid portion of a mold used in forming a quadrangular pyramid projection in Comparative Example 1-6.

Fig. 4 is a view showing a ridge-like uneven shape formed on the coating layer when the unevenness is formed on the coating layer by using a roll having a meandering unevenness in Comparative Example 1-7.

Fig. 5 is a schematic view showing a cross section of a film cut by a sheet slicing device when measuring the coverage of a film formed by a transparent projection. Further, the symbol a in Fig. 5 means "no transparent protrusion". The part marked "", the symbol b means "measured length in each direction: 3 mm".

Fig. 6 is a schematic view showing a cross section of a film cut by a sheet slicing device when measuring the coverage of a film formed by a transparent protrusion formed of transparent particles. Further, the symbol c in Fig. 6 means "no. The portion covered by the transparent protrusions, the symbol d means "measured length in each direction: 3 mm".

Fig. 7 is a schematic view showing a cross section of a film cut by a sheet slicing device when measuring the coverage of a film formed by a transparent protrusion formed of transparent particles. Further, the symbol e in Fig. 7 means " The portion which is not covered by the transparent particles", the symbol f means "the measured length in each direction is 3 mm".

Claims (6)

A reflective film for a lighting device comprising a white film and a reflective film having a transparent protrusion having a height of 3 to 50 μm provided on a surface of the white film, wherein the white film is composed of a thermoplastic resin. And a film which exhibits a white color by a void-forming substance in the film, wherein the transparent protrusion is composed of transparent particles, and the transparent particles having an exposure rate of 5 to 100% on the surface of the reflective film are 50 to 100%. The coverage is coated on the surface of the white film, and the transparent particles are carried on the surface of the white film by a coating film of a binder. The reflective film of claim 1, wherein the transparent particles have an average particle diameter of 3 to 50 μm. For example, in the reflective film of claim 2, wherein the transparent particle has a volume 50% particle diameter D50 of 3 to 50 μm, and the ratio of the transparent particle volume 10% particle diameter D10 to the volume 90% particle diameter D90 is D10/D90 is 0.30. ~0.98. The reflective film of claim 1, wherein the coating film of the adhesive is composed of a binder composition containing a phosphor, and the content of the phosphor in the binder composition is the total of the binder composition. When the weight is based on, it is 1 to 20% by weight. For example, in the reflective film of claim 4, wherein the fluorescent system is excited by light of a wavelength of 400 to 450 nm, and a wave of 500 to 600 nm is obtained. Long-glow-emitting organic phosphor. The reflective film according to any one of claims 1 to 5, wherein the illumination device is a backlight unit of the liquid crystal display device.