JP2013007782A - Polyarylate light diffusion film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusion film which has high light diffusibility and high light transmittance with respect to LED light sources, while having antifouling properties and excellent scratch resistance, the light diffusion film being suitable for use in an LED light or an LED display device.SOLUTION: A polyarylate light diffusion multilayer film comprises: a photocatalyst layer 2; a film layer 1 in which light diffusion materials, which are composed of fine silicone particles, are dispersed in a polyarylate resin; and an adhesive layer 3. The photocatalyst layer 2 serves as the outermost layer on one surface of the film, and the adhesive layer 3 serves as the outermost layer on the other surface of the film. The polyarylate light diffusion multilayer film may also comprise a hard coat layer 4.

Description

  The present invention relates to a light diffusing film, and more particularly to a light diffusing film that can be suitably used for various illumination devices, various display devices and the like having an LED light source.

  In recent years, various types of displays and lighting devices using LEDs (light emitting diodes) as light sources have been provided. Of these, white LEDs used as light sources for illumination are expected to use near ultraviolet LEDs as excitation sources as light sources for next-generation lighting devices and image display devices because of their high color rendering properties. The LED has low power consumption and excellent long-term reliability, but has a characteristic that the directivity of light is strong and the irradiation light is difficult to spread. That is, the illumination device of the LED light source irradiates light with high luminance in a certain direction, but the luminance is weak in other directions. For this reason, when the illuminating device is viewed directly from a specific direction, the eye irritation may be too strong, and there is an inconvenience that unevenness in illumination luminance occurs depending on the illumination location.

  Therefore, the light emitted from the LED is passed through a light diffusing member to diffuse the light in various directions, so that it is not known which LED emitted the light. By concealing the LED light source, the entire light emitted from the LED is made uniform, so that unevenness in illumination luminance does not occur.

  Conventionally, a light diffusing member used for illumination has been mainly an acrylic molded light diffusing plate kneaded with titanium oxide or the like. However, there is a problem in that the light transmittance is reduced when the concealability of the LED light source is increased. In addition, polycarbonate and polyethylene terephthalate films have been used as support films for imparting light diffusivity, but these are insufficient in wear resistance and low birefringence, and particularly for LED light sources that generate large amounts of heat from the light source. When used, the heat resistance was insufficient. When a diffusion film used for a liquid crystal display (LCD) backlight or the like is used as a light diffusion film of an LED light source, the light transmittance is high, but there is a problem that the concealability is insufficient due to low diffusion.

  Patent Document 1 proposes a light diffusion sheet in which a light diffusion layer made of a transparent resin layer, plastic beads, and a resin is provided on a plastic film. This light diffusing sheet effectively uses the light diffusibility by the plastic beads, but the illumination device using the LED as the light source can maintain the light transmittance, but the LED light source is sufficiently concealed. I can't say that. Depending on the application, post-processing such as covering the surface of the light diffusing sheet with other functional parts may be applied, so that the surface is easily scratched, which may cause uneven brightness. . Further, when the water-based transparent resin layer is continuously applied for production, the transparent resin layer is likely to be scratched and uneven brightness may occur. On the other hand, by increasing the coating temperature of the transparent resin layer, it is possible to accelerate the curing of the coating film and improve the scratch resistance. In the case of forming on the opposite side, if an aqueous coating solution is used for forming the hard coat layer, the hard coat layer may be cracked by increasing the coating temperature.

  Patent Document 2 proposes a light diffusion sheet in which a two-layer light diffusion layer is formed on a polyester film and has an aqueous hard coat layer. In particular, when used in an illumination device using LEDs as a light source, the light transmittance can be improved, but the light diffusibility is not sufficient, and there is a risk of uneven brightness.

  Furthermore, since the outermost surface layer of the light diffusion sheets of Patent Document 1 and Patent Document 2 is a hard coat layer, dirt may adhere over time and the appearance may deteriorate.

Japanese Patent No. 3485613 JP 2011-065139 A

  The present invention was made in order to solve the problems of conventional light diffusion sheets. The LED light source has high light diffusibility and light transmittance, is provided with antifouling properties, and has excellent scratch resistance. Alternatively, it is an object to provide a light diffusion film suitable for use in an LED display device.

  The polyarylate-based light diffusing laminated film according to claim 1 of the present invention, which has been made to achieve the above object, comprises a photocatalyst layer and a light diffusing layer comprising silicone fine particles in a polyarylate-based resin. It has a film layer in which the material is dispersed and an adhesive layer, wherein the photocatalyst layer is an outermost layer on one surface, and the adhesive layer is an outermost layer on the other surface.

  Similarly, the polyarylate-based light diffusion laminate film of the invention according to claim 2 is the polyarylate-based light diffusion laminate film according to claim 1, wherein the film layer and the photocatalyst layer, and the film layer, It has a hard-coat layer between at least one between the said adhesion layers.

  The polyarylate-based light diffusion laminated film of the invention according to claim 3 is the polyarylate-based light diffusion laminated film according to claim 2, wherein the hard coat layer is made of a silicone-based hard coat material. To do.

  The polyarylate-based light diffusing laminated film of the invention according to claim 4 is the polyarylate-based light diffusing laminated film according to claim 3, wherein the silicone-based hard coat material is a photo-curable silicone-based hard coat material. It is characterized by being.

  The polyarylate-based light diffusing laminated film of the invention according to claim 5 is the polyarylate-based light diffusing laminated film according to claim 1, wherein the light diffusing material comprising the silicone-based fine particles has an average particle size of 0.05 μm. It is 10 μm or less.

  The polyarylate-based light diffusing laminated film of the invention according to claim 6 is the polyarylate-based light diffusing laminated film according to claim 5, wherein the refractive index difference between the polyarylate-based resin and the silicone-based fine particles is It is 0.01 or more and 0.3 or less.

  The polyarylate-based light diffusion laminated film of the invention according to claim 7 is the polyarylate-based light diffusion laminated film according to claim 1 or 2, wherein the adhesive layer is made of a silicone-based adhesive material. To do.

  The polyarylate-based light diffusing laminated film of the invention according to claim 8 is the polyarylate-based light diffusing laminated film according to claim 1 or 2, wherein the photocatalyst layer comprises photocatalyst particles and a water-soluble binder. It is formed by applying a liquid.

  A polyarylate-based light diffusing laminated film according to claim 9 is the polyarylate-based light diffusing laminated film according to claim 8, wherein the photocatalyst particles are crystal fine particles of a metal oxide having n-type semiconductor properties. A metal selected from the group consisting of vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, rhodium, silver, tin, tungsten, platinum, gold, a metal oxide, or / And photocatalyst particles carrying a metal compound.

  The polyarylate-based light diffusion laminate film of the invention according to claim 10 is the polyarylate-based light diffusion laminate film according to claim 8, wherein the water-soluble binder contains hydrolyzable silicon compound, water, basic It contains a compound hydrolyzed in a mixed solvent of a compound and a polar solvent.

  The polyarylate-based light diffusion laminate film of the invention according to claim 11 is characterized in that the total light transmittance of the polyarylate-based light diffusion laminate film according to any one of claims 1 to 10 is 60% or more. To do.

  Furthermore, the polyarylate-based light diffusing laminated film of the invention according to claim 12 made to achieve the above object is the polyarylate-based light diffusing laminated film according to any one of claims 1 to 11. And is used for LED lighting.

  Similarly, the polyarylate-based light diffusion laminated film of the invention according to claim 13 is the polyarylate-based light diffusion laminated film according to any one of claims 1 to 11, and is used for an LED display device. And

  Since the polyarylate-based light diffusion laminated film of the present invention has high light diffusibility of the LED light source, it has excellent light source concealing property despite its high light transmittance. The total light transmittance is over 80%. Moreover, since the outermost layer is provided with a photocatalyst layer, the antifouling property is also excellent. Since the adhesive layer is provided in the other outermost layer, it can be easily attached to the LED light source. Furthermore, a polyarylate-based light diffusion laminated film that is hard to be scratched on the surface can be obtained with a configuration provided with a hard coat layer.

It is a schematic cross section of an example of a polyarylate-based light diffusion laminated film to which the present invention is applied. It is a schematic cross section of another example of the polyarylate-type light diffusion laminated film to which the present invention is applied. It is a schematic cross section of another example of the polyarylate-based light diffusion laminated film to which the present invention is applied. It is a schematic cross section of another example of the polyarylate-based light diffusion laminated film to which the present invention is applied.

  Hereinafter, the polyarylate-based light diffusion laminated film according to the present invention will be described in detail with reference to embodiments. However, these embodiments are suitable application examples according to the present invention and do not limit the present invention. In this specification, “resin” means a polymer compound exclusively.

  FIG. 1, which is the first embodiment of the present invention, shows a polyarylate-based light diffusion laminated film having a photocatalyst layer 2 on one side of a light diffusion film layer 1 and an adhesive layer 3 on the other side. Has been. The light diffusing film layer 1 is obtained by dispersing a light diffusing material in a polyarylate resin.

  In FIG. 2, which is the second embodiment of the present invention, the light diffusing film layer 1 has hard coat layers 4 and 4 on both sides, and further has a photocatalyst layer 2 on one side of the outermost surface. A polyarylate-based light diffusion laminated film having an adhesive layer 3 on the outermost surface is shown.

  In FIG. 3, which is the third embodiment of the present invention, the light diffusing film layer 1 has a hard coat layer 4 on one side, and further has an adhesive layer 3 on its outermost surface. A polyarylate-based light diffusion laminate film having a photocatalyst layer 2 on one side is shown.

  In FIG. 4, which is the fourth embodiment of the present invention, the light diffusing film layer 1 has a hard coat layer 4 on one side and further has a photocatalyst layer 2 on its outermost surface. A polyarylate-based light diffusion laminated film having an adhesive layer 3 on one surface is shown.

(1: Light diffusion film layer)
The polyarylate-based resin constituting the light diffusion film layer of the present invention is not particularly limited, and those known as polyarylate that can be used for optical applications can be used. Polyarylate-based resins are superior to polycarbonate and polyethylene terephthalate films, which are frequently used as the base of the light diffusion film layer, and are superior in wear resistance and low birefringence. Especially, they are used for LED light sources that generate a large amount of heat from the light source. Has sufficient heat resistance.

  The polyarylate resin is an aromatic polyester resin made of a polymer of dihydric phenol and aromatic dicarboxylic acid. Examples of such polyarylate resins include U-100, P-1001, and P- 1001A exists.

  The light diffusing material that is added to and dispersed in the polyarylate resin as the light diffusing film layer is preferably silicone fine particles. For example, silicone powder X-52-7077, KSP-300, KMP-597, X-52-1621, etc. manufactured by Shin-Etsu Chemical Co., Ltd. can be used. These may be used individually by 1 type and may use 2 or more types together.

  The average particle diameter of the light diffusing material comprising silicone fine particles is preferably 0.05 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 8 μm or less. By setting the average particle size to 0.1 μm or more and 5 μm or less, sufficient light transmittance, sufficient scratch resistance in the production process, and sufficient light diffusing ability can be expressed, and more uniform formation can be achieved.

  The addition amount of the light diffusing material composed of silicone fine particles is preferably 1 part by mass or more and 300 parts by mass or less, more preferably 5 parts by mass or more with respect to 100 parts by mass of the polyarylate resin (solid content). 200 parts by mass or less. By making the addition amount of the fine particles within this range, it is possible to achieve both the light diffusibility and the light transmittance of the LED light source. If the addition amount is 1 part by mass or less, the light diffusibility of the LED light source cannot be sufficiently obtained, and if it is 300 parts by mass or less, the light transmittance of the LED light source cannot be obtained sufficiently, and the film becomes very brittle. There is a disagreement.

  The refractive index difference between the polyarylate resin of the light diffusion film layer and the silicone fine particles as the light diffusion material is preferably 0.01 or more and 0.3 or less. When the refractive index difference is 0.01 or more and 0.3 or less, the light diffusibility and light transmittance of the LED light source can be improved.

  The light diffusing film layer is obtained by forming a film obtained by adding and kneading a light diffusing material to a polyarylate resin and dispersing it. For film formation, a melt extrusion molding method is preferable from the viewpoint of economy. In the case of carrying out by the melt extrusion molding method, the molding method and the like are not particularly limited. For example, either the T-die method or the inflation method may be used. Although it may be an unstretched film, it is preferably stretched in at least one direction within a temperature range of 120 to 160 ° C. during or after melt extrusion molding. This stretching operation can improve the heat resistance and optical properties of the film.

  Although the thickness of a light-diffusion film layer can be chosen arbitrarily according to the objective, it is preferable that it is 150 micrometers or more as a LED illumination use. More preferably, it is 200 μm or more. Furthermore, in applications where the rigidity of the polyarylate-based light diffusion laminated film is required, the thickness is preferably 250 μm or more. The light diffusion film layer is thicker than any of the other layers (hard coat layer, photocatalyst layer, adhesive layer).

(2: Photocatalyst layer)
As the photocatalyst layer in the polyarylate-based light diffusing laminated film of the present invention, a photocatalyst film obtained by applying a photocatalyst coating solution comprising photocatalyst particles and a water-soluble binder and drying and curing it is suitable. Provides antifouling effect to polyarylate-based light diffusion laminated film.

As the photocatalyst particles, crystal oxide fine particles of metal oxides that are n-type semiconductors such as titanium oxide-based, tungsten oxide-based, zinc oxide-based, and niobium oxide-based on the market can be used. For example, anatase type titanium dioxide (TiO ₂ ), rutile type titanium dioxide (TiO ₂ ), tungsten trioxide (WO ₃ ), zinc oxide (ZnO), Ga-doped zinc oxide (GZO), niobium oxide (Nb ₂ O) ₅ ) etc. can be used. Among them, those having high visible light activity, those doped with nitrogen, sulfur, phosphorus, carbon, etc. in the crystal of these metal oxides, or copper, iron, nickel, gold, silver, platinum, carbon, etc. supported on the surface A thing can use it conveniently. More specifically, rutile-type titanium oxide carrying platinum, rutile-type titanium oxide carrying iron, rutile-type titanium oxide carrying copper, rutile-type titanium oxide carrying copper hydroxide, anatase-type titanium oxide carrying gold And tungsten trioxide carrying platinum. Further, those having a fine primary particle diameter, that is, a primary particle diameter in the range of 1 to 100 nm, preferably in the range of 1 to 50 nm, are preferably used. When the primary particle size is larger than 100 nm, the transparency of the coating film is lowered and the appearance may be impaired.

  As such photocatalyst fine particles having high visible light activity, MPT-623 (visible light responsive photocatalyst, powder, rutile titanium dioxide carrying platinum; manufactured by Ishihara Sangyo Co., Ltd.), MPT-625 (visible light) Responsive photocatalyst, powder, rutile type titanium dioxide carrying iron; manufactured by Ishihara Sangyo Co., Ltd.) and the like.

The water-soluble binder of the photocatalyst coating liquid can be suitably obtained by a method of hydrolyzing a silicon alkoxide represented by the following formula (1) or a condensate thereof in water, a basic compound, and a polar solvent.
Si (OR) _X (OH) _4-X (1)

In formula (1), R is independently a hydrogen atom or a functional group. R may be the same or different from each other. Specific examples of the functional group R include a hydrogen atom (H), a methyl group (CH ₃ ), an ethyl group (CH ₂ CH ₃ ), a propyl group (CH ₂ CH ₂ CH ₃ ), and an isopropyl group (CH ₂ ( CH ₃ ) CH ₃ ), a butyl group (CH ₂ CH ₂ CH ₂ CH ₃ ), an alkoxysilyl group (Si (OCH ₂ CH ₂ ) ₃ ) and the like.

  Of these, tetramethoxysilane (wherein R is all methyl) and tetraethoxysilane (wherein R is all ethyl) are particularly preferable.

As a basic compound contained in the water-soluble binder of the photocatalyst coating solution and used for hydrolysis of silicon alkoxide, R _X —NH _{4 -X} (2) represented by the following formula (2)

In formula (2), R is independently a hydrogen atom or a functional group. R may be the same or different from each other. Specific examples of the functional group R include a hydrogen atom (H), a methyl group (CH ₃ ), an ethyl group (CH ₂ CH ₃ ), a propyl group (CH ₂ CH ₂ CH ₃ ), and an isopropyl group (CH ₂ ( CH ₃ ) CH ₃ ), butyl group (CH ₂ CH ₂ CH ₂ CH ₃ ), methylol group (CH ₂ OH), and ethylol group (CH ₂ CH ₂ OH). In addition, it substitutes with functional groups other than a hydrogen atom, and takes the form of the quaternary amine shown by following formula (3).
^{_{R 4 N + X - ··· (}} 3)

It may be a salt with a counter anion represented by X ⁻ in formula (3). Specific examples of X include a hydroxy group (OH), halogen (F, Cl, Br, I) and the like. Of these, tetramethylammonium hydroxide can be suitably used.

  Part of water-soluble binders, polar solvents used for the reaction with silicon alkoxide and basic compounds include water, alcohols (eg, methanol, ethanol, isopropanol), glycols (eg, glycerin, methyl cellosolve, ethyl cellosolve) , Propyl cellosolve, or acetic acid esters thereof) and ketones (for example, acetone, diacetone alcohol, acetylacetone, methyl ethyl ketone). The polar solvent may be used alone or in combination of two or more. Of these, acetone can be preferably used.

  Silicon alkoxide, basic compound, polar solvent and water are mixed and stirred, and the resulting product is dissolved in water or alcohol and adjusted to pH = 5 to 8 by acid addition or ion exchange. As a result, the silicon alkoxide is hydrolyzed.

  In the photocatalyst coating liquid, the photocatalyst particles are dispersed, and the hydrolyzed silicate prepared under the above conditions is dissolved or dispersed. It is prepared by preparing a photocatalyst dispersion in which photocatalyst particles are dispersed in a solvent in advance, and mixing and stirring. Specific examples of such a photocatalyst coating liquid include TA-801-G, TA-802-G, and TA-803-G manufactured by Shin-Etsu Chemical Co., Ltd.

  The photocatalyst solid content concentration in the photocatalyst coating liquid is 0.01 to 10% by mass, preferably 0.1 to 5% by mass. If the photocatalyst solid content concentration is less than 0.01% by mass, the antifouling activity due to the photocatalyst may be reduced. If the photocatalyst solid content concentration is more than 10% by mass, the transparency may be deteriorated and the appearance may be impaired. Moreover, the solid content concentration of the photocatalyst and the hydrolyzed silicate in the coating liquid is 0.05: 99.5 to 99.5: 0.05 as a photocatalyst solid content mass: silicate solid content mass ratio, preferably 5: 95-95: 5. When the photocatalyst mass ratio is less than 5, sufficient hydrophilicity and antifouling activity due to oxidative decomposition cannot be obtained, and when it is more than 95, the strength of the film is low and peeling or cracking may occur.

  The base material to which the photocatalyst coating solution is applied is not particularly limited as long as a thin film can be formed. Any conventionally known method can be used to apply the photocatalyst coating liquid to the substrate. Specifically, the dip coating method, spin coating method, spray coating method, mark coating method, impregnation method, roll method, wire bar method, die coating method, gravure printing method, inkjet method, etc. It can be formed on a substrate.

  The film thickness of the coating film to be formed is preferably in the range of 1 to 500 nm, particularly 50 to 300 nm. If the film thickness is too thin, the strength may be low, and if it is too thick, cracks may occur.

  In order to apply the photocatalyst coating solution and dry and cure the coating film, it is preferable to perform the treatment for 1 to 120 minutes in a temperature range of 50 to 200 ° C, particularly 5 to 60 in a temperature range of 60 to 110 ° C. It is preferable to process for a minute.

(3: Adhesive layer)
A silicone adhesive material is suitable as a material for the adhesive layer for attaching the polyarylate-based light diffusion laminated film to the LED light source.

  As the silicone pressure-sensitive adhesive material, it is possible to use a commonly used pressure-sensitive adhesive material composed of a thermosetting chain organopolysiloxane and a solid silicone resin. There are two types of thermosetting silicone adhesives: organic peroxide curing type and platinum addition curing type. When stretchable polyethylene film or polypropylene film is used as the base material, it may be deformed by heat. It is particularly preferable to use a platinum addition-curing silicone adhesive that can be cured at a low temperature. The curing condition for the silicone adhesive is usually 80 to 150 ° C.

The organic peroxide curable silicone pressure-sensitive adhesive material comprises a chain-like organopolysiloxane, (R ₃ SiO _1/2 ) units, and (SiO ₂ ) units (R is a substituted or unsubstituted monovalent hydrocarbon group). Organopolysiloxane copolymer resin (organopolysiloxane mixture with (R ₃ SiO _1/2 ) molar ratio of (R ₃ SiO _1/2 ) units to (SiO ₂ ) units of 0.5 to 1.5), and benzoylpar as a cross-linking curing agent It contains an organic peroxide such as oxide, bis (4-methylbenzoyl) peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane. The platinum addition-curing silicone adhesive is composed of a chain-like vinyl group-containing organopolysiloxane, the organopolysiloxane copolymer resin, an organohydrogenpolysiloxane containing silicon-bonded hydrogen atoms as a crosslinking curing agent, and a chlorination as a catalyst. It contains a platinum group metal catalyst such as platinum acid, alcohol-modified chloroplatinic acid, platinum olefin complex, platinum complex with vinylsiloxane.

  Examples of such silicone-based pressure-sensitive adhesives include X-40-3270 / CAT-PL-50T = 100 / 0.5, X-40-3229 / CAT-PL-50T = 100/0. 5, X-40-3323 / CAT-PL-50T = 100 / 0.25.

  The thickness of the silicone adhesive layer is preferably 5 to 100 μm, more preferably 10 to 50 μm.

(4: Hard coat layer)
The hard coat layer provided on the polyarylate-based light diffusion laminate film of the present invention is preferably a silicone-based hard coat material. From the viewpoint of the workability of the formation, a photo-curable silicone hard coat material is more preferable. It is formed from a photoreactive group-containing siloxane compound, a (meth) acrylic group-containing compound, and a radical photopolymerization initiator. Specifically, there are Shin-Etsu Chemical Co., Ltd. KP-1001, X-12-2437 and the like. A coating film made of this coating solution is coated on the light diffusion film layer and cured by UV lamp irradiation to obtain a hard coat layer.

  The method for forming the hard coat layer is not particularly limited, and a known coater may be appropriately selected and applied according to the purpose. For example, the application | coating by a reverse roll coater, a wire bar, and a curtain coater is mentioned. The film thickness of the formed film is preferably in the range of 0.1 to 50 μm, particularly 0.5 to 30 μm. If the film thickness is too thin, the wear resistance may decrease, and if it is too thick, the crack resistance may decrease.

As a light source for curing the hard coat layer, a light source containing light having a wavelength in the range of 200 to 450 nm, for example, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a carbon arc lamp, or the like may be used. it can. Although the amount of irradiation is not particularly limited, it is preferably 10 to 5,000 mJ / cm ² , particularly preferably ²⁰ to 2,000 mJ / cm ² . The curing time is usually 0.5 second to 2 minutes, preferably 1 second to 1 minute.

  When the scratch resistance is not required, the polyarylate-based light diffusing laminated film of the present invention does not necessarily include a hard coat layer, and is optional such as being provided only on one side of the light diffusing film layer.

  Each layer of the polyarylate-based light diffusion laminated film may further contain an additive. Furthermore, another layer may be provided and an additive may be included in the provided layer. Further, it may be included in a plurality of layers. Especially, it is preferable to make it contain in the polyarylate-type resin of a light-diffusion film layer. This is because a sufficient inclusion effect can be obtained even when the additive concentration is low by containing the polyarylate resin thicker than the other layers. For example, when an ultraviolet absorber is used as an additive as described later, a sufficient ultraviolet absorption effect can be obtained even if the concentration of the ultraviolet absorber is low by including it in the polyarylate resin.

  The first additive is an ultraviolet absorber, and the second additive is an antioxidant for preventing oxidation caused by light or heat, and HALS (Hindered Amine Light Stabilizer). is there. The first additive and the second additive may be included in different layers, or may be included in the same layer.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by these examples. The present invention can be implemented with appropriate modifications within a range that can meet the gist of the present invention, and both are included in the technical scope of the present invention.

  The measurement / evaluation methods employed in the examples are as follows. In the examples, “parts” means “parts by mass” unless otherwise specified, and “%” means “% by mass” unless otherwise specified.

1. Measurement of diffuseness of transmitted light Measurement is performed using an automatic variable angle photometer (GP-200: manufactured by Murakami Color Research Co., Ltd.).
Transmission measurement mode, light incident angle: 60 °, light receiving angle: −90 ° to 90 °, SENSITIVITY: 150, HIGH VOLTON: 500, filter: use ND10, luminous flux stop: 10.5 mm (VS-1 3.0), Light receiving stop: 9.1 mm (VS-3 4.0) and angular width (degrees) from the rising start angle to the ending angle of the transmission peak, which can be measured under the condition of a variable angle interval of 0.1 degree, and Find the peak height. The angular width is the diffusivity, and the peak height is the transmittance.

2. Total light transmittance It measured based on JISK7105-1981 using the Nippon Denshoku Industries Co., Ltd. haze measuring device "NDH-2000".

3. Film appearance The surface of the film was visually observed and judged by the presence or absence of appearance defects such as the presence or absence of a wavy pattern. A product having no appearance defect was judged good and a product having a bad appearance was judged defective.

4). Confirmation of antifouling property Antifouling property is applied by spreading 1 mL of a methylene blue aqueous solution adjusted to 10 μmol / L on a diffusion film cut out to 5 cm × 5 cm, and illuminating white LED light so that the amount of light on the sample surface becomes 10,000 Lux. After irradiation for 3 hours, the blue color disappeared and the change was not observed as x.

Example 1
100 parts by mass of polyarylate resin (manufactured by Unitika, U-100) and 10 parts by mass of silicone powder (manufactured by Shin-Etsu Chemical Co., Ltd., X-52-7077; average particle size 5 μm) are melt-extruded in advance with a biaxial extruder. The kneaded polyarylate-based resin composition thus obtained was melt-mixed in a 60 mmφ single screw extruder (L / D; 22) at a resin temperature of 350 ° C. and extruded with a T die, and then cast at 130 ° C. An unstretched sheet was obtained by cooling with a roll. Next, this unstretched sheet was stretched 4 times at a stretching temperature of 120 ° C. using a roll peripheral speed difference of a longitudinal stretching machine to obtain a polyarylate-based light diffusion film having a thickness of 250 μm. A photocatalyst coating solution (TA-801-G, manufactured by Shin-Etsu Chemical Co., Ltd.) containing photocatalyst particles dispersed in a solvent by a wire bar method and containing a water-soluble silicate binder on one side of the polyarylate-based light diffusion film This was applied and heat-treated in an oven at 100 ° C. for 30 minutes to obtain a photocatalyst layer having a thickness of 200 nm. On the other surface of the polyarylate-based light diffusing film, a silicone-based adhesive (X-40-3270 / CAT-PL-50T = 100 / 0.5, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied by the wire bar method, It heat-processed for 2 minutes in 130 degreeC oven, and obtained the 30-micrometer-thick adhesion layer.

  The polyarylate-based light diffusing laminated film of Example 1 obtained in this way has the cross section shown in FIG. 1 and the measured values and characteristics are shown in Table 1. This polyarylate-based light diffusing laminated film has good concealability of the LED light source, excellent transparency, diffusivity, and total light transmittance, and has a good appearance and high quality. .

(Example 2)
A polyarylate-based light diffusion laminated film was obtained in the same process as in Example 1 except that the uniaxially stretched film prepared in Example 1 was further stretched 3 times in the transverse direction. The polyarylate-based light diffusion laminated film of Example 2 obtained in this way has the cross section shown in FIG. 1 and the measured values and characteristics are shown in Table 1. This polyarylate-based light diffusing laminated film had good concealability of the LED light source, excellent transparency, diffusivity, and total light transmittance, and had a good appearance and high quality.

(Example 3)
A photocurable silicone hard coat material (Shin-Etsu Chemical Co., Ltd., KP-1001) was applied to both surfaces of the uniaxially stretched film prepared in Example 1 by a wire bar method, and light having a wavelength of 375 nm was 1200 mJ / mm with a high-pressure mercury lamp. Irradiation with cm ² for 1 minute gave a hard coat layer with a thickness of 3 μm. Further, a photocatalyst coating liquid (TA-801-G, manufactured by Shin-Etsu Chemical Co., Ltd.) containing photocatalyst particles dispersed in a solvent by a wire bar method on one side of the polyarylate-based light diffusion film and containing a water-soluble silicate binder. And heat-treated in an oven at 100 ° C. for 30 minutes to obtain a photocatalyst layer having a thickness of 200 nm. On the other surface of the polyarylate-based light diffusing film, a silicone-based adhesive (X-40-3270 / CAT-PL-50T = 100 / 0.5, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied by the wire bar method, It heat-processed for 2 minutes in 130 degreeC oven, and obtained the 30-micrometer-thick adhesion layer. The polyarylate-based light diffusing laminated film of Example 3 obtained in this way has the cross section shown in FIG. 2 and the measured values and characteristics are shown in Table 1. This polyarylate-based light diffusing laminated film had good concealability of the LED light source, excellent transparency, diffusivity, and total light transmittance, and had a good appearance and high quality.

(Comparative Example 1)
In the method of Example 1, a light diffusing film was obtained in the same manner as in Example 1 except that the silicone powder was changed to 10 parts by mass of acrylic powder (Chemisnow MX-500; average particle size 5 μm, manufactured by Soken Chemical Co., Ltd.). It was. Table 1 shows the characteristics of the resulting polyarylate-based light diffusion laminated film of Comparative Example 1. This polyarylate-based light diffusing laminated film has excellent diffusivity, but the total light transmittance was not good.

(Comparative Example 2)
A light diffusion film was obtained by laminating a diffusion layer made of acrylic resin beads on one side of a 250 μm thick polyarylate film by a coating method. The properties of the obtained light diffusing film of Comparative Example 2 are shown in Table 1. All of these light diffusion films had a low diffusivity ratio, and the balance between transmittance and diffusivity was not good.

(Comparative Example 3)
A light diffusion film was obtained by laminating a diffusion layer made of polystyrene polymer beads on one side of a 250 μm thick polyarylate film by a coating method. The properties of the obtained light diffusing film of Comparative Example 3 are shown in Table 1. All of these light diffusion films had a low diffusivity ratio, and the balance between transmittance and diffusivity was not good. Moreover, the defect of the wavy pattern was observed on the surface.

1: Light diffusion film layer 2: Photocatalyst layer 3: Adhesive layer 4: Hard coat layer

Claims (13)

  A photocatalyst layer, a film layer in which a light diffusing material made of silicone fine particles is dispersed in a polyarylate-based resin, and an adhesive layer. The photocatalyst layer is an outermost layer on one side, and the adhesive layer is A polyarylate-based light diffusion laminated film, which is the outermost layer on the other surface.   2. The polyarylate-based light diffusion according to claim 1, further comprising a hard coat layer between at least one of the film layer and the photocatalyst layer and between the film layer and the adhesive layer. Laminated film.   The polyarylate-based light diffusion laminated film according to claim 2, wherein the hard coat layer is made of a silicone-based hard coat material.   The polyarylate-based light diffusion laminated film according to claim 3, wherein the silicone-based hard coat material is a photo-curable silicone-based hard coat material.   2. The polyarylate-based light diffusion laminated film according to claim 1, wherein the light diffusion material comprising the silicone-based fine particles has an average particle diameter of 0.05 μm or more and 10 μm or less.   6. The polyarylate-based light diffusion laminated film according to claim 5, wherein a difference in refractive index between the polyarylate-based resin and the silicone-based fine particles is 0.01 or more and 0.3 or less.   The polyarylate-based light diffusion laminated film according to claim 1, wherein the adhesive layer is made of a silicone-based adhesive material.   The polyarylate-based light diffusion laminated film according to claim 1 or 2, wherein the photocatalyst layer is formed by applying a coating liquid containing photocatalyst particles and a water-soluble binder.   The photocatalyst particles are vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, rhodium, silver, tin, tungsten, platinum on crystal fine particles of metal oxide having n-type semiconductivity. The polyarylate-based light diffusion laminated film according to claim 8, which is a photocatalyst particle supporting a metal selected from the group consisting of gold, a metal oxide, and / or a metal compound.   9. The polyarylate-based light diffusion laminate according to claim 8, wherein the water-soluble binder contains a hydrolyzable silicon compound hydrolyzed in a mixed solvent of water, a basic compound and a polar solvent. the film.   The polyarylate-based light diffusion laminate film according to any one of claims 1 to 10, wherein the total light transmittance of the polyarylate-based light diffusion laminate film is 60% or more.   It is used for LED illumination, The polyarylate type | system | group light-diffusion laminated | multilayer film in any one of Claims 1-11 characterized by the above-mentioned.   The polyarylate-based light diffusion laminated film according to any one of claims 1 to 11, wherein the polyarylate-based light diffusion laminated film is used in an LED display device.

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