JP2013072885A - Resin composition for formation of light diffusion film and method for manufacturing the same, light diffusion film, light diffusing and reflecting member, light diffusing and transmitting member and optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for formation of a light diffusion film capable of forming a light diffusion film which can impart high light diffusion even to light having high directivity such as LED.SOLUTION: A resin composition for formation of a light diffusion film of the present invention has an average long diameter of 1 μm or more and 5 μm or less and an average short diameter of 0.5 μm or more and 3 μm or less, and comprises aggregated particle pieces having at least one acute end and a resin, wherein the aggregated particle pieces are contained in the amount of 15 mass% or more and 45 mass% or less based on the total mass of the aggregated particle pieces and the resin.

Description

  The present invention relates to a resin composition for forming a light diffusion film and a method for producing the same, a light diffusion film, a light diffusion reflection member, a light diffusion transmission member, and an optical element. In particular, a light diffusing film forming resin composition suitable for use in imparting light diffusibility to an optical component using LED light, a manufacturing method thereof, and a light diffusing film forming resin composition are used. The present invention relates to a light diffusion film.

Conventionally, as a structure that imparts light diffusibility to glass products, sand blasting is performed on the glass surface or hydrofluoric acid treatment is performed on the glass surface to provide light diffusibility by providing irregularities on the surface. The structure is known.
However, such a structure has a problem that a thin glass may be cracked and it is difficult to uniformly treat the surface.

  In view of this, a light scattering film (Patent Document 1) is proposed in which a composition for a light scattering film containing an organic transparent resin and fine particles having a refractive index different from that of the transparent resin is applied on a substrate by a die coating method.

JP 2007-187824 A

  By the way, in the light-scattering film which applied the composition for light-scattering films containing the organic type transparent resin and microparticles | fine-particles of patent document 1, only the interface effect by the refractive index of resin and microparticles differing is utilized. Therefore, there is a problem that it is insufficient to diffuse light having high directivity such as an LED.

  This invention is made | formed in view of the said situation, Comprising: The light-diffusion film | membrane which can provide high light diffusibility also to light with high directivity like LED can be formed. It aims at providing the resin composition for light-diffusion film formation, its manufacturing method, and a light-diffusion film.

  As a result of earnest studies to solve the above problems, the present inventors have made the aggregated particle pieces in a shape having a major axis and a minor axis of a desired size and having one or more acute end portions, and a resin. It was found that a resin composition having high light diffusibility can be obtained by mixing.

  That is, the resin composition for forming a light diffusion film of the present invention has an average major axis of 1 μm or more and 5 μm or less, an average minor axis of 0.5 μm or more and 3 μm or less, and an aggregate having at least one sharp edge. A particle piece and a resin are contained, and the aggregated particle piece is contained in an amount of 15% by mass or more and 45% by mass or less with respect to a total mass of the aggregated particle piece and the resin. .

  The aggregated particle pieces are preferably made of crushed pieces or crushed pieces obtained by crushing or pulverizing the aggregated particle bodies.

  The method for producing a resin composition for forming a light diffusing film of the present invention comprises crushing or aggregating aggregated particles into aggregated particle pieces having an average major axis of 1 μm to 5 μm and an average minor axis of 0.5 μm to 3 μm. It has a dispersion | distribution process disperse | distributed to a solvent, grind | pulverizing, and a process which mixes the dispersion liquid obtained by the said dispersion | distribution process, and resin.

  The light diffusion film of the present invention is formed by the resin composition for forming a light diffusion film of the present invention.

  The light diffusing and reflecting member of the present invention is characterized in that the light diffusing film of the present invention is formed on the surface of a substrate having a visible light reflectance of 95% or more.

  The light diffusing and transmitting member of the present invention is characterized in that the light diffusing film of the present invention is formed on the surface of a substrate having a visible light transmittance of 90% or more.

  The optical member of the present invention is characterized by comprising at least one of the light diffusion film, the light diffusion reflection member, and the light diffusion transmission member.

  According to the resin composition for forming a light diffusing film of the present invention, the average major axis is 1 μm or more and 5 μm or less, the average minor axis is 0.5 μm or more and 3 μm or less, and has at least one sharp end. Since the aggregated particle pieces and the resin component are contained, a resin composition for forming a light diffusing film having excellent light diffusibility can be obtained.

  According to the method for producing a resin composition for forming a light diffusing film of the present invention, the aggregated particle pieces can have many sharp edges by crushing or pulverizing the aggregated particle bodies, and thus excellent in light diffusibility. In addition, a resin composition for forming a light diffusing film can be produced.

  According to the light diffusion film of the present invention, since the resin composition for forming a light diffusion film of the present invention is formed, excellent light diffusibility can be obtained.

  According to the light diffusing and reflecting member of the present invention, the light diffusing film made of the resin composition for forming a light diffusing film of the present invention is formed on the surface of a base material having a visible light reflectance of 95% or more. The light diffusibility and light reflectivity can be obtained.

  According to the light diffusing and transmitting member of the present invention, the light diffusing film made of the resin composition for forming a light diffusing film of the present invention is formed on the surface of a base material having a visible light transmittance of 90% or more. The light diffusibility and light transmittance can be obtained.

  According to the optical member of the present invention, excellent characteristics can be obtained with respect to at least one of light diffusibility, light diffusivity, and light diffusivity.

It is a schematic diagram which shows an example of the aggregated particle body and aggregated particle piece which concern on embodiment. It is a schematic diagram which shows another example of the aggregated particle body and aggregated particle piece which concern on embodiment. It is a schematic diagram which shows another example of the aggregated particle piece which concerns on embodiment. It is a schematic diagram which shows another example of the aggregated particle piece which concerns on embodiment.

The form for implementing the resin composition for light-diffusion film formation of this invention, its manufacturing method, and a light-diffusion film is demonstrated.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

[Resin composition for forming light diffusing film]
The resin composition for forming a light diffusion film of this embodiment has an average major axis of 1 μm or more and 5 μm or less, an average minor axis of 0.5 μm or more and 3 μm or less, and an agglomeration having at least one sharp edge. Particle pieces and a resin are contained, and the aggregated particle pieces are contained in an amount of 15% by mass to 45% by mass with respect to the total mass of the aggregated particle pieces and the resin.
The average major axis is preferably 2 μm or more and 5 μm or less, the average minor axis is preferably 0.5 μm or more and 2 μm or less, and the average aspect ratio (major axis / minor axis) is preferably 1.5 or more.

"Agglomerated particle fragments"
The term “aggregation” in the present specification means that aggregated particle pieces having irregularities on the surface are formed by aggregation of primary particles. Concavities and convexities formed on the surface include at least concavities and convexities formed by gaps between constituent particles (primary particles or aggregates of primary particles), and are given by the shape of constituent particles (primary particles or aggregates of primary particles). It may contain irregularities.

The constituent particles constituting the aggregated particle pieces are not particularly limited as long as they are inorganic oxide particles. For example, particles such as silica, titania, zirconia, zinc oxide, and alumina can be used.
The material of the constituent particles may be determined according to the use of the light diffusion film to be formed. For example, by using primary particles having a small refractive index difference from the resin, the light transmittance of the light diffusing film can be increased, and therefore, the resin composition is suitable as a resin composition for forming the light diffusing and transmitting film.
On the other hand, by using constituent particles having a large refractive index difference from the resin, the light reflectivity of the light diffusing film can be increased, so that it is suitable as a resin composition for forming the light diffusing and reflecting film.

  The agglomerated particle pieces have at least one sharp edge. The acute-angled end referred to here is the end of the aggregated particle piece on which a pyramidal or conical protrusion having an acute apex angle is formed. In order to improve light diffusibility, the aggregated particle pieces preferably have a plurality of sharp end portions, and more preferably have a large number of sharp end portions.

Further, such a sharp end is preferable because a crushed piece or a crushed piece obtained by crushing or pulverizing the aggregated particle body has a wide variety of shapes.
The aggregated particle body is not particularly limited as long as the average major axis is an aggregate of 1 μm or more in which a plurality of constituent particles (primary particles or aggregates of primary particles) are aggregated. As the agglomerated particles, it is preferable to use spherical agglomerated particles having an average major axis of 1 μm or more and 5 μm or less. This makes it easy to adjust the major and minor diameters of the agglomerated particle pieces to a desired size.

The major and minor diameters of the agglomerated particle pieces are within a certain range and have sharp edges. The shape of the aggregated particle piece itself is indefinite, and it is preferable that various shapes are mixed. By setting it as such a shape, light with high directivity like LED light can be light-diffused. The effect is that the size of the aggregated particle pieces (primary particles or aggregates of primary particles) is large enough to cause light to diffuse, and the surface of the aggregated particle pieces formed by the aggregation of the particles is uneven. And it is presumed that the light diffusion effect of light is further enhanced by the sharp edges of the aggregated particle pieces.
In addition, even if it is a small aggregate piece with an average major axis of less than 1 μm or an average minor axis of less than 0.5 μm, it may be mixed as long as the light diffusibility of the light diffusion film is not lowered.

Examples of the aggregated particle pieces include those shown in FIGS.
FIG. 1B, FIG. 2B, FIG. 3 and FIG. 4 are diagrams showing a plurality of examples of aggregated particle pieces of the present embodiment. FIGS. 1 (a) and 2 (a) show aggregated particle bodies as starting materials for the aggregated particle pieces shown in FIGS. 1 (b) and 2 (b), respectively. 1 to 4 show measurement examples of the major axis L and minor axis S of one aggregated particle piece.

  Aggregated particle pieces 11 to 16 shown in FIG. 1B are obtained by agglomerating primary particles 2 having an average particle size of about 1 nm to 50 nm, and the gaps between the primary particles 2 are fine irregularities on the surface of the aggregated particle pieces. Is forming. Aggregated particle pieces 11 to 16 each have at least one sharp end. The average major axis of the aggregated particle pieces 11 to 16 is 1 μm to 5 μm, and the average minor axis is 0.5 μm to 3 μm.

  Aggregated particle pieces 11 to 16 shown in FIG. 1B can be produced by crushing or pulverizing the aggregated particle body 1 shown in FIG. Aggregated particle body 1 is formed by agglomerating primary particles 2 having an average particle diameter of 1 nm to 50 nm in a spherical shape having a cavity 3 therein. The average particle diameter of the aggregated particle body 1 is preferably 1 μm or more and 5 μm or less, more preferably 2 μm or more and 3 μm or less. A plurality of cavities 3 may be formed, and a part of the cavities 3 may communicate with the outside of the aggregated particle body 1.

  Aggregated particle pieces 31 to 38 shown in FIG. 2 (b) are formed by agglomerating particles having a primary particle diameter of about 1 nm to 50 nm to form fine irregularities between the primary particles, and at least one sharp edge. The aggregated particle pieces have an average major axis of 1 μm to 5 μm and an average minor axis of 0.5 μm to 3 μm.

  Aggregated particle pieces 31 to 38 shown in FIG. 2B can be produced by pulverizing or crushing the aggregated particle body 21 shown in FIG. Aggregated particle body 21 is formed by agglomerating primary particles 2 having an average particle diameter of 1 nm to 50 nm in a solid spherical shape. The average particle diameter of the aggregated particle body 21 is preferably 1 μm or more and 5 μm or less, and more preferably 2 μm or more and 3 μm or less.

  Aggregated particle pieces 42 shown in FIG. 3 are obtained by arbitrarily laminating plate-like particles 41 to form an aggregated particle piece. Aggregated particle pieces 42 are also formed in a shape having an average major axis of 1 μm to 5 μm and an average minor axis of 0.5 μm to 3 μm. In the aggregated particle pieces 42, the gaps between the plate-like particles 41 form irregularities, and the corners of the plate-like particles 41 form sharp edges.

  The size of the plate-like particles 41 is not particularly limited as long as the aggregated particle pieces 42 satisfy the specified dimensions of the average major axis and the average minor axis, but the average length of one side of the main surface portion is 0.5 μm to 3 μm, the average thickness It is preferable to use plate-like particles having a thickness of 0.1 μm to 2 μm.

  Aggregated particle pieces 45 shown in FIG. 4 are formed by agglomerating laminated particles 44, which are a laminate of a plurality of plate-like particles 43. In the laminated particles 44, the plate-like particles 43 are laminated in an orderly manner so as to form a rectangular parallelepiped shape as a whole. Aggregated particle pieces 45 are also formed in a shape having an average major axis of 1 μm to 5 μm and an average minor axis of 0.5 μm to 3 μm. In the agglomerated particle pieces 42, the gaps between the laminated particles 44 form irregularities, and the corners of the laminated particles 44 form sharp edges.

  The size of the laminated particles 44 is not particularly limited as long as the aggregated particle pieces 45 satisfy the specified dimensions of the average major axis and the average minor axis, but the average length of one side of the main surface portion is 0.5 μm to 3 μm, and the average thickness. It is preferable to use a laminate in which about 2 to 10 plate-like particles 43 having a particle size of 0.1 to 2 μm are laminated.

  As the aggregated particle pieces, aggregated particle pieces 11 to 16 obtained by crushing or pulverizing the spherical aggregated particle body 1 shown in FIG. 1A or the aggregated particle body 21 shown in FIG. 31-38 are preferred. Aggregated particle pieces formed by crushing or pulverization are easy to obtain irregular and sharp corners, which makes it easy to obtain excellent light diffusibility. Of the aggregated particle bodies 1 and 21, the hollow aggregated particle body 1 is easier to obtain an irregularly shaped aggregated particle piece.

In any of the aggregated particle pieces 11 to 16, 31 to 38, 42 and 45 shown in FIGS. 1 to 4, the average major axis is 1 μm or more and 5 μm or less, and the average minor axis is 0.5 μm or more and 3 μm or less. is there. By setting the average major axis and the average minor axis of the aggregated particle pieces in the above range, a coating film having high light diffusibility and no coating unevenness can be formed.
Here, the average major axis means the average value of the length of the longest part of each aggregated particle piece (major axis L), and the average minor axis means the length of the shortest part of each aggregated particle piece (short axis). It means the average value of the diameter S).

"resin"
The resin is preferably a curable resin such as thermoplasticity, thermosetting, light (electromagnetic wave) curable by visible light, ultraviolet light or infrared light, electron beam curable by electron beam irradiation, or a silicon-containing inorganic-organic hybrid structure. Used. In order to suppress light loss in the light diffusion film, it is preferable to use a resin that is transparent to visible light.

  Examples of these resins include epoxy resins, acrylic resins, fluorine resins, phenol resins, polyester resins, polyvinyl chloride resins, acrylic / polysiloxane hybrid resins, epoxy / polysiloxane hybrid resins, urethane / polysiloxane hybrid resins, and the like. . Among these resins, an epoxy resin or an acrylic resin is preferable because it is excellent in light transmittance and light diffusibility, and excellent in heat resistance and mechanical properties.

  The resin composition for forming a light diffusion film of the present embodiment is obtained by dispersing the aggregated particle pieces in a liquid resin monomer or a liquid resin oligomer, or by mixing one or more of the resins in these dispersions. May be.

As the liquid resin monomer, acrylic or methacrylic monomers such as methyl acrylate and methyl methacrylate, epoxy monomers and the like are preferably used.
Moreover, as a liquid resin oligomer, a urethane acrylate oligomer, an epoxy acrylate oligomer, an acrylate oligomer, or the like is preferably used. Hereinafter, the term “resin” includes monomers and oligomers.

  The mixing ratio of the resin and the aggregated particle pieces is 15% by mass to 45% by mass with respect to the total mass of the resin and the aggregated particle pieces. By setting the mixing ratio of the resin and the aggregated particle pieces in the above range, the mechanical properties such as the mechanical strength of the film obtained by applying the resin composition, and the optical properties such as light diffusivity, transmittance, and reflectance. Good characteristics can be obtained in both cases.

The light diffusing film forming resin composition of the present embodiment may be mixed with a solvent as needed. As the solvent, at least one of water and an organic solvent is preferably used.
Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol, butanol, octanol, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, γ-butyrolactone, and the like. Esters, diethyl ether, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol monobutyl ether (butyl cellosolve), ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetone, methyl ethyl ketone , Methyl isobutyl ketone, acetylacetone, cyclohexanone, etc. S, benzene, toluene, xylene, ethylbenzene, etc., dimethylformamide, N, N- dimethylacetamide, amides such as N- methyl pyrrolidone is preferably used. These organic solvents may be used alone or in combination of two or more.

  When the aggregated particle pieces are dispersed in the solvent, the content of the aggregated particle pieces is preferably 1% by mass or more and 70% by mass or less, more preferably 1% by mass with respect to the total mass of the solvent and the aggregated particle pieces. It is more than 50 mass%, More preferably, it is 5 mass% or more and 30 mass% or less.

  Here, if the content rate of an aggregated particle piece is the said range, an aggregated particle piece will be in a favorable dispersion state with respect to a solvent. However, when the content is less than 1% by mass, the amount of the solvent is excessive when mixed with the resin, and the handling property for obtaining a coating film is deteriorated. Moreover, when it exceeds 70 mass%, since the uniformity as a coating material may fall, it is unpreferable.

  In the composition of the present embodiment, generally used additives such as a dispersant, an antifoaming agent, a leveling agent, a lubricant, an antioxidant, a light stabilizer, a polymerization inhibitor, etc., as long as the characteristics are not lost. May be added as appropriate.

[Method for producing resin composition for forming light diffusion film]
The method for producing a resin composition for forming a light diffusing film according to this embodiment is such that the aggregated particles are crushed into aggregated particle pieces having an average major axis of 1 μm to 5 μm and an average minor axis of 0.5 μm to 3 μm. Or it is a manufacturing method which has a dispersion | distribution process disperse | distributed to a solvent, grind | pulverizing, and the process of mixing the dispersion liquid obtained by the said dispersion | distribution process, and resin.

"Dispersion process"
In the dispersion step, the agglomerated particles are dispersed in a solvent, a resin monomer, or a resin oligomer while being crushed or pulverized into aggregated particle pieces having an average major axis of 1 μm to 5 μm and an average minor axis of 0.5 μm to 3 μm. This is a step of obtaining a dispersion. These agglomerated particles, solvent, resin monomer, and resin oligomer are those described above.

Agglomerated particles having a desired shape (a shape having an average major axis of 1 μm to 5 μm, an average minor axis of 0.5 μm to 3 μm, and having sharp edges) by crushing or pulverizing the aggregated particles In order to uniformly disperse the formed agglomerated particle pieces in a solvent or the like while forming the pieces, a method using a dispersing device can be mentioned. Examples of such a dispersing device include a bead mill, a ball mill, and a jet mill. Among these, a bead mill is preferable.
In addition, you may disperse | distribute an agglomerated particle body to a solvent etc. using what was previously crushed with the crusher etc. FIG.

"Mixing process"
The mixing step refers to a step of mixing the dispersion obtained in the dispersing step and the resin.
The mixing method is not particularly limited as long as the dispersion and the resin are uniformly mixed, and a known mixing method can be used.
As described above, the resin composition for forming a light diffusion film of the present embodiment can be obtained.

[Light diffusion film]
The light diffusing film of this embodiment is formed by the light diffusing film forming composition of this embodiment.
The film thickness of the light diffusion film is not particularly limited, and may be adjusted as appropriate according to the application. In the case of a light diffusion film that diffuses highly directional light such as LED light, it is preferably 1 μm or more and 30 μm or less. A film thickness of less than 1 μm is not preferable because the light diffusion performance of the film is poor. On the other hand, if the film thickness exceeds 30 μm, cracks or cracks may occur on the surface, which is not preferable.

The method for producing a light diffusing film of the present embodiment includes a step of forming the light diffusing film forming resin composition into a film shape and a step of curing the formed film.
The method for forming the light diffusing film-forming resin composition into a film is not particularly limited, and a method of forming a coating film by applying the resin composition to a substrate, or a method of flowing into a molding die of any shape Can be used.

The base material to which the resin composition for forming a light diffusion film is applied is not particularly limited, and a glass base material or a plastic base material can be used.
Also, the application method is not particularly limited, and examples thereof include a spin coating method, a dip coating method, a gravure coating method, a spray method, a roller method, a bar coating method, and a brush coating method.

  As a curing method in the step of curing the coating film, a heat curing method or a photocuring method may be used according to the resin to be used. The energy rays used for photocuring are not particularly limited as long as the coating is cured, and for example, energy rays such as ultraviolet rays, far infrared rays, near ultraviolet rays, infrared rays, X rays, γ rays, electron beams, proton rays, neutron rays are used. be able to. Among these energy rays, curing by ultraviolet irradiation, which has a high curing rate and is easily available, is preferable.

[Light diffuse reflection member]
In the light diffusing and reflecting member of this embodiment, a light diffusing film made of the composition for forming a light diffusing film of the previous embodiment is formed on at least one surface of a substrate having a visible light reflectance of 95% or more. It will be.
Here, the reflectance of visible light of 95% or more means that the average reflectance of 380 nm to 800 nm is 95% or more with reference to a MgO standard white plate.

  The film thickness of the light diffusion film may be adjusted as appropriate, but when light having high directivity such as LED light is diffused and reflected, it is 1 μm or more and 30 μm or less, preferably 5 μm or more and 20 μm or less. A film thickness of less than 1 μm is not preferable because a desired light diffusion reflection performance may not be obtained in the light diffusion film. On the other hand, if the film thickness exceeds 30 μm, cracks or cracks occur on the surface of the light diffusion film, which is not preferable.

"Base material"
The base material used for the light diffusion reflection member is not particularly limited as long as the visible light reflectance is 95% or more.
For example, a film with a metal reflective layer such as a silver-deposited PET film, a white film such as a white PET film, a white polypropylene film, a white polycarbonate film, aluminum, aluminum with a mirror finish or anodized, and white paint Examples thereof include an aluminum substrate such as aluminum and a foamed white polyester film. These substrates may be bonded to a support such as metal.

  As the white film, commercially available products such as Lumirror 60L, Lumirror 60V, Lumirror 60SL, Lumirror 60SV, PP reflector manufactured by Mitsui Chemical Co., Ltd., and Mpetpet manufactured by Furukawa Electric Co., Ltd. are also used as the white film. be able to.

  The light diffusing and reflecting member of the present embodiment uses the above-mentioned base material having a visible light reflectance of 95% or more, and the same coating method and curing method as those for the light diffusing film described above are performed. Can be manufactured.

[Light diffusion and transmission member]
In the light diffusing and transmitting member of this embodiment, a light diffusing film made of the light diffusing film forming composition of the previous embodiment is formed on at least one surface of a base material having a visible light transmittance of 90% or more. It will be.
Here, the transmittance of visible light of 90% or more means that the average transmittance in a wavelength region of 380 nm to 800 nm with reference to air is 90% or more.

"Base material"
The base material used for the light diffusing and transmitting member is not particularly limited as long as the visible light transmittance is 90% or more. For example, a glass substrate or a plastic substrate can be used.

  The light diffusing and transmitting member of the present embodiment is manufactured by using a base material having a visible light transmittance of 90% or more and performing the same coating method and curing method as the method for manufacturing a light diffusing film described above. be able to.

"Optical element"
The optical member of this embodiment includes at least one of the light diffusion film, the light diffusion reflection member, and the light diffusion transmission member of the previous embodiment.
The optical element is not limited as long as it is an optical element used for light diffusion. For example, as an optical element provided with a light diffusive reflecting member, a light diffusing plate used for illumination light path control in a lighting fixture or a backlight unit for a liquid crystal display can be cited.

The method for forming the light diffusing film on the optical element is not particularly limited. For example, the light diffusing film may be mounted on the optical member by using the light diffusing film forming method described above or a known method.
The method for mounting the light diffusing and reflecting member and the light diffusing and transmitting member of the previous embodiment on the optical element is not particularly limited, and may be mounted on the optical element by a known method.

  As described above, according to the resin composition for forming a light diffusion film of the present embodiment, the average major axis is 1 μm to 5 μm, the average minor axis is 0.5 μm to 3 μm, and at least one By containing the aggregated particle pieces having sharp edges and the resin component, it is possible to form a light diffusion film having excellent light diffusibility.

  In the case where a crushed piece or a crushed piece obtained by crushing or pulverizing an aggregated particle body is used as the aggregated particle piece, the aggregated particle piece forms a large number of sharp end portions, and the aggregated particle piece Since there are a wide variety of shapes, a resin composition capable of forming a light diffusing film with more excellent light diffusibility can be obtained.

  Further, according to the method for producing a resin composition for forming a light diffusion film of the present embodiment, the aggregated particle pieces are formed by crushing or pulverizing the aggregated particle bodies. Therefore, the aggregated particle pieces having many sharp edges are included. A resin composition can be produced, and a resin composition capable of forming a light diffusion film excellent in light diffusibility can be produced.

  Moreover, according to the light diffusing film of the present embodiment, excellent light diffusibility can be obtained by using the light diffusing film forming resin composition of the present embodiment. Moreover, it is excellent in in-plane uniformity of the film surface, and there is no risk of cracking in the film or the substrate. And the light-diffusion film | membrane of this embodiment can also be formed in a curved part.

  The light diffusing and reflecting member of the present embodiment is excellent in light diffusion because the light diffusing film made of the resin composition for forming a light diffusing film of the present embodiment is formed on the surface of a substrate having a reflectance of 95% or more. And light reflectivity can be obtained. Further, light can be reflected almost uniformly in the visible light region with a wavelength of 380 nm to 800 nm without wavelength dependency. In addition, there is no risk of cracking in the film or the substrate, and the in-plane uniformity of the film surface is excellent.

  The light diffusing and transmitting member of this embodiment is excellent because the light diffusing film made of the resin composition for forming a light diffusing film of this embodiment is formed on the surface of a base material having a visible light transmittance of 90% or more. Light diffusibility and light transmittance can be obtained. In addition, light can be transmitted substantially uniformly in the visible light region with a wavelength of 380 nm to 800 nm without wavelength dependency. In addition, there is no risk of cracking in the film or substrate, and the in-plane uniformity of the film surface is excellent.

  According to the optical element of the present embodiment, since it comprises at least one of the light diffusing film, the light diffusing reflection member, and the light diffusing and transmitting member of the present embodiment, the light diffusing property, the light diffusing and reflecting property, and the light diffusing and transmitting property are provided. An optical element excellent in at least one performance can be obtained.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.

"Resin composition for forming light diffusion film and light diffusion reflection film"
[Example 1]
Hollow spherical silica aggregate A having an average major axis of 2.3 μm (Suzuki Yushi Kogyo Co., Ltd., God Ball B-6C, primary particle diameter of aggregated particles 20 nm to 30 nm) (aggregated particle aggregate), pure water containing a dispersant and beads The mixture was pulverized and dispersed using a bead mill, and then the beads were separated to prepare a dispersion containing 20% by mass of aggregated particle pieces and 2% by mass of a dispersant.

  When 100 aggregated particle pieces in the dispersion were observed using a scanning electron microscope S-4000 (manufactured by Hitachi High-Tech), the average major axis was 2 μm and the average minor axis was 1 μm.

  Next, an acrylic resin is added to this dispersion so that the aggregated particle pieces are 20% by mass with respect to the total mass of the acrylic resin and the aggregated particle pieces, and mixed uniformly to form the light diffusion film of Example 1. A resin composition was prepared.

  Next, this light diffusion film forming resin composition was applied on a white reflective film (Lumirror E60L, manufactured by Toray Industries, Inc.) by a bar coating method so that the film thickness was 1.5 μm, and the obtained coating film was applied. Then, the film was dried in air at 90 ° C. for 5 minutes while air blowing to obtain a light diffusion reflection film (light diffusion reflection member) of Example 1.

[Example 2]
In the same manner as in Example 1, except that the content of the aggregated particle pieces in the resin composition for forming a light diffusing film was 30% by mass, the resin composition for forming a light diffusing film and the light of Example 2 were used. A diffuse reflection film was obtained.

[Example 3]
In the same manner as in Example 1, except that the content of the aggregated particle pieces in the resin composition for forming a light diffusion film was 40% by mass, the resin composition for forming a light diffusion film and the light of Example 3 were used. A diffuse reflection film was obtained.

[Example 4]
In Example 1, instead of the spherical silica aggregate A, a solid spherical silica aggregate B having an average major axis of 3 μm (manufactured by Tosoh Silica Co., Ltd., nip gel SS-170X primary particle diameter of 1 nm to 10 nm) ( The resin composition for forming a light diffusing film and the light diffusing reflective film of Example 4 were obtained in the same manner except that the agglomerated particles were changed.
When the aggregated particle pieces in the dispersion were observed in the same manner as in Example 1, the average major axis was 2 μm and the average minor axis was 1 μm.

[Example 5]
In Example 4, the resin composition for forming a light diffusing film and light of Example 5 were used in the same manner except that the content of the aggregated particle pieces in the light diffusing film forming resin composition was 30% by mass. A diffuse reflection film was obtained.

[Example 6]
In Example 4, the resin composition for forming a light diffusing film and light of Example 6 were used in the same manner except that the content of the aggregated particle pieces in the resin composition for forming a light diffusing film was 40% by mass. A diffuse reflection film was obtained.

[Example 7]
The light of Example 7 was obtained in the same manner as in Example 1 except that instead of the spherical silica aggregate A, a plate-like silica aggregate C having an average major axis of 5 μm (Sun Lovely manufactured by AGC S-Tech Co., Ltd.) was used. A resin composition for forming a diffusion film and a light diffusion reflection film were obtained.
When the aggregated particle pieces in the dispersion were observed in the same manner as in Example 1, the average major axis was 5 μm and the average minor axis was 3 μm.

[Example 8]
The resin composition for forming a light diffusing film and the light of Example 8 were prepared in the same manner as in Example 7, except that the content of the aggregated particle pieces in the light diffusing film forming resin composition was 30% by mass. A diffuse reflection film was obtained.

[Example 9]
The resin composition for forming a light diffusing film and the light of Example 9 were prepared in the same manner as in Example 7, except that the content of the aggregated particle pieces in the resin composition for forming a light diffusing film was 40% by mass. A diffuse reflection film was obtained.

[Example 10]
In Example 1, a resin composition for forming a light diffusion film and a light diffusion reflection film of Example 10 were obtained in the same manner except that a polyester resin was used instead of the acrylic resin.

[Example 11]
In Example 1, a resin composition for forming a light diffusion film and a light diffusion reflection film of Example 10 were obtained in the same manner except that a fluororesin was used instead of the acrylic resin.

[Comparative Example 1]
In Example 1, the resin composition for forming a light diffusing film and the light of Comparative Example 1 were similarly used except that the content of the aggregated particle pieces in the resin composition for forming a light diffusing film was 10% by mass. A diffuse reflection film was obtained.

[Comparative Example 2]
In the same manner as in Example 1, except that the content of the aggregated particle pieces in the resin composition for forming a light diffusion film was 50% by mass, the resin composition for forming a light diffusion film and the light of Comparative Example 2 were used. A diffuse reflection film was obtained.

[Comparative Example 3]
In Example 4, the resin composition for forming a light diffusion film and the light of Comparative Example 3 were similarly used except that the content of the aggregated particle pieces in the resin composition for forming a light diffusion film was 10% by mass. A diffuse reflection film was obtained.

[Comparative Example 4]
In Example 4, the resin composition for forming a light diffusing film and the light of Comparative Example 4 were similarly used except that the content of the aggregated particle pieces in the resin composition for forming a light diffusing film was 50% by mass. A diffuse reflection film was obtained.

[Comparative Example 5]
In Example 7, the resin composition for forming a light diffusion film and the light of Comparative Example 5 were similarly used except that the content of the aggregated particle pieces in the resin composition for forming a light diffusion film was 10% by mass. A diffuse reflection film was obtained.

[Comparative Example 6]
The resin composition for forming a light diffusing film and the light of Comparative Example 6 were prepared in the same manner as in Example 7 except that the content of the aggregated particle pieces in the resin composition for forming a light diffusing film was 50% by mass. A diffuse reflection film was obtained.

[Comparative Example 7]
In Example 1, instead of the spherical silica aggregate A, a hollow spherical silica aggregate D having an average major axis of 9 μm (Suzuki Yushi Kogyo Co., Ltd. God Ball B-25C Aggregated particle primary particle diameter 20 nm to 30 nm) (aggregated particle) The resin composition for forming a light diffusing film and the light diffusing and reflecting film of Comparative Example 7 were obtained in the same manner except that the body) was used.
When the aggregated particle pieces in the dispersion were observed in the same manner as in Example 1, the average major axis was 7 μm and the average minor axis was 4 μm.

[Comparative Example 8]
In Example 1, in place of the spherical silica aggregate A, a hollow spherical silica E (Silinax SP-PN (b) manufactured by Nittetsu Mining Co., Ltd.) having an average major axis of 0.1 μm that is not an aggregated particle was used. In the same manner, a resin composition for forming a light diffusion film and a light diffusion reflection film of Comparative Example 8 were obtained.
When particles in the dispersion were observed in the same manner as in Example 1, the average major axis was 0.1 μm and the average minor axis was 0.1 μm.

[Comparative Example 9]
In Example 1, instead of the spherical silica aggregate A, an amorphous fused silica pulverized product F (Suzuki Yushi Kogyo Godball G-6C) having an average major axis of 4 μm and not an aggregated particle is used. The resin composition for forming a light diffusion film and the light diffusion reflection film of Comparative Example 9 were obtained in the same manner.
When the particles in the dispersion were observed in the same manner as in Example 1, the average major axis was 4 μm and the average minor axis was 4 μm.

[Comparative Example 10]
In Example 1, in place of the spherical silica aggregate A, a comparative example is used except that spherical alumina G having an average major axis of 3 μm (advanced alumina AA-3 manufactured by Sumitomo Chemical Co., Ltd.), which is not an aggregated particle, is used. Ten resin compositions for forming a light diffusion film and a light diffusion reflection film were obtained.
When particles in the dispersion were observed in the same manner as in Example 1, the average major axis was 3 μm and the average minor axis was 3 μm.

[Comparative Example 11]
In Example 1, instead of the spherical silica aggregate A, a comparative example is used except that spherical titania H (A-100 manufactured by Ishihara Sangyo Co., Ltd.) having an average major axis of 0.1 μm, which is not an aggregated particle, is used. 11 resin compositions for forming a light diffusion film and a light diffusion reflection film were obtained.
When particles in the dispersion were observed in the same manner as in Example 1, the average major axis was 0.1 μm and the average minor axis was 0.1 μm.

[Comparative Example 12]
In Example 1, instead of the hollow spherical silica aggregate A having an average major axis of 2 μm, solid spherical silica I (SS-50F manufactured by Tosoh Silica Corp.) having an average major axis of 1 μm which is not an aggregated particle was used. Similarly, the resin composition for forming a light diffusion film and the light diffusion reflection film of Comparative Example 12 were obtained.
When the particles in the dispersion were observed in the same manner as in Example 1, the average major axis was 1 μm and the average minor axis was 1 μm.

  Each characteristic of the integrated reflectance of the light diffusive reflection film obtained in each of Examples 1 to 11 and Comparative Examples 1 to 12, the wavelength variation of the reflectance, the light diffusibility of the LED light, and the coating unevenness is evaluated by the following methods. did. The evaluation results are shown in Table 1.

(1) Integral reflectance at 550 nm White reflectance is measured using a spectrophotometer V-570 (manufactured by JASCO Corporation) with an integral reflectance (R (%)) of the light diffusive reflective film in a wavelength range of 380 nm to 800 nm. It measured on the basis of the reflectance of a film (Lumirror E60L by Toray Industries, Inc.).
The reflection characteristics were evaluated based on the following criteria according to the value of the integrated reflectance (%) when the wavelength was 550 nm. In addition, all reflectivity (%) is the value measured in the state which interposed the film used as a base material in formation of a light-diffusion reflection film.
◎: Reflectance is 98% or more ○: Reflectance is 95% or more and less than 98% △: Reflectance is 90% or more and less than 95% ×: Reflectance is less than 90%

(2) Wavelength variation of reflected light The difference between the maximum value and the minimum value of the integrated reflectance was calculated in the wavelength range of 380 nm to 800 nm measured in (1). And according to the difference of the obtained reflectance (%), the wavelength variation characteristic of reflected light was evaluated based on the following reference | standard.
◎: Difference is less than 3% ○: Difference is 3% or more and less than 6% △: Difference is 6% or more and less than 9% ×: Difference is 9% or more

(3) Light diffusibility of LED light The LED element emits light with the light diffusing cover of the LED white light bulb (DL-L601N manufactured by Sharp Corporation) having six LED elements removed, and white light is emitted to the light diffusion reflection film. Was directly irradiated. In this case, depending on whether the shape of the element of the LED light source is reflected as it is, the light diffusibility characteristics of the LED light were evaluated based on the following criteria.
◎: LED light source diffuses and element shape does not appear ×: LED light source does not diffuse light and element shape reflects as it is

(4) Coating unevenness The light diffusive reflection film was visually observed, and the characteristics of coating unevenness were evaluated based on the following criteria.
A: No coating unevenness is observed at all.
X: Coating unevenness is observed.

"Light diffusing and permeable membrane"
[Example 12]
In Example 1, the light diffusion transmission of Example 12 was similarly performed except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film (manufactured by Toray Industries Inc., Lumirror E60L). A film (light diffusing and transmitting member) was obtained.

[Example 13]
In Example 2, a light diffusing / transmitting film of Example 13 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 14]
In Example 3, a light diffusing and permeable film of Example 14 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 15]
In Example 4, a light diffusing / transmitting film of Example 15 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 16]
In Example 5, a light diffusing / transmitting film of Example 15 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 17]
In Example 6, a light diffusing / transmitting film of Example 17 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 18]
In Example 7, a light diffusing and transmitting film of Example 18 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 19]
In Example 8, a light diffusing / transmitting film of Example 19 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 20]
In Example 9, a light diffusing and transmitting film of Example 20 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 21]
In Example 10, a light diffusing / transmitting film of Example 21 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Example 22]
In Example 11, a light diffusing / transmitting film of Example 22 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 13]
In Comparative Example 1, a light diffusing / transmitting film of Comparative Example 13 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 14]
In Comparative Example 2, a light diffusing and transmitting film of Comparative Example 14 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 15]
In Comparative Example 3, a light diffusing / transmitting film of Comparative Example 15 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 16]
In Comparative Example 4, a light diffusing and transmitting film of Comparative Example 16 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 17]
In Comparative Example 5, a light diffusing / transmitting film of Comparative Example 17 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 18]
In Comparative Example 6, a light diffusing / transmitting film of Comparative Example 18 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 19]
In Comparative Example 7, a light diffusing / transmitting film of Comparative Example 19 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 20]
In Comparative Example 8, a light diffusing / transmitting film of Comparative Example 20 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 21]
In Comparative Example 9, a light diffusing / transmitting film of Comparative Example 21 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 22]
In Comparative Example 10, a light diffusing / transmitting film of Comparative Example 22 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 23]
In Comparative Example 11, a light diffusing and transmitting film of Comparative Example 23 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

[Comparative Example 24]
In Comparative Example 12, a light diffusing / transmitting film of Comparative Example 24 was obtained in the same manner except that a glass substrate (20 mm × 50 mm × 2 mmt) made of borosilicate glass was used instead of the white reflective film.

  Each characteristic of the haze value, total light transmittance, wavelength variation of transmittance, and film formability of the light diffusing and transmitting films obtained in Examples 12 to 22 and Comparative Examples 13 to 24 was evaluated by the following methods. The evaluation results are shown in Table 2.

(5) Haze value and total light transmittance The haze value and total light transmittance of the light diffusion transmission film were measured using a haze meter NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).
The haze value was evaluated based on the following criteria.
◎: Haze value is 60% or more ○: Haze value is 40% or more and less than 60% △: Haze value is 20% or more and less than 40% ×: Haze value is less than 20%

The total light transmittance (%) was evaluated based on the following criteria.
◎: Total light transmittance is 90% or more ○: Total light transmittance is 85% or more and less than 89% Δ: Total light transmittance is 80% or more and less than 85% ×: Haze value is less than 80%

(6) Wavelength variation of transmitted light Glass substrate made of borosilicate glass using a spectrophotometer V-570 (manufactured by JASCO Corporation) with an integrated transmittance (T (%)) in the wavelength range of 380 nm to 800 nm. It measured on the basis of the transmittance | permeability (20 mm x 50 mm x 2 mmt).
The difference between the maximum value and the minimum value of the obtained integral transmittance was calculated, and the wavelength variation characteristics of the transmitted light were evaluated based on the following criteria according to the difference.
◎: Difference is less than 6% ○: Difference is 6% or more and less than 10% △: Difference is 10% or more and less than 20% ×: Difference is 20% or more

(7) Coating unevenness The coating unevenness was performed in exactly the same manner as the evaluation method (4) and evaluation criteria.

1,21 Aggregated particle body 2 Primary particle 3 Cavity 11-16, 31-38, 42, 45 Aggregated particle piece 41, 43 Plate-like particle 44 Laminated particle

Claims (7)

  The average major axis is 1 μm or more and 5 μm or less, the average minor axis is 0.5 μm or more and 3 μm or less, and contains aggregated particle pieces having at least one acute end, and the resin, A resin composition for forming a light diffusing film, wherein the particle pieces are contained in an amount of 15% by mass to 45% by mass with respect to the total mass of the aggregated particle pieces and the resin.   2. The light diffusion film formation according to claim 1, wherein the aggregated particle pieces are formed of crushed pieces or crushed pieces obtained by crushing or pulverizing aggregated particle bodies having an average major axis of 1 μm or more and 5 μm or less. Resin composition.   Dispersion in which agglomerated particles are dispersed in a solvent, a liquid resin monomer, or a liquid resin oligomer while being crushed or pulverized into aggregated particle pieces having an average major axis of 1 μm to 5 μm and an average minor axis of 0.5 μm to 3 μm The method for producing a resin composition for forming a light diffusing film according to claim 1, comprising a step of mixing a resin obtained by the step and the dispersion obtained in the dispersion step.   A light diffusing film, which is formed from the resin composition for forming a light diffusing film according to claim 1.   5. A light diffusing and reflecting member, wherein the light diffusing film according to claim 4 is formed on the surface of a substrate having a visible light reflectance of 95% or more.   A light diffusing and transmitting member, wherein the light diffusing film according to claim 4 is formed on the surface of a substrate having a visible light transmittance of 90% or more.   An optical element comprising at least one of the light diffusion film according to claim 4, the light diffusion reflection member according to claim 5, and the light diffusion transmission member according to claim 6.

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