TW201803946A - Light guide plate composition and light guide plate - Google Patents

Abstract

The invention provides a light guide plate composition and a light guide plate, and the light guide plate composition can be used to produce a light guide plate capable of uniformly emitting light to a light exit surface with a higher luminance, and the storage stability is excellent. The composition for a light guide plate contains light diffusion particles (A) and a dispersion medium (B). The reflectivity of a hardened film with thickness of 10 [mu]m made of the compositionlight is is 0% to 50% for light whose wavelength is bleow 300 nm to 380 nm, and reflectivity of light whose wavelength is bleow 400 nm to 800 nm is 30% to 99%.

Description

Composition for light guide plate and light guide plate

The present invention relates to a composition for a light guide plate, and a light guide plate which is particularly suitable for an edge light-emitting type surface light-emitting device.

As the surface light-emitting device used in a liquid crystal display panel, a billboard, or the like, there are known a straight-down type in which light sources are arranged in a planar shape and a uniform light emission is formed by a diffusion plate or the like, and an edge-emitting type in which a light source is arranged on an end surface of a light guide plate .

The edge-emitting surface-emitting device includes a light source and a light guide plate. The light guide plate includes a light guide substrate and a light diffusion portion, and light from a light source propagates inside the light guide plate, and is emitted in a planar shape by a light diffusion portion disposed on a surface of the light guide substrate. Such a light guide plate is manufactured by applying a composition for a light guide plate containing light diffusion particles to a light guide substrate as described in Patent Documents 1 to 4 to produce a light diffusion portion. [Prior Art Literature]

[Patent Literature] [Patent Literature 1] Japanese Patent Laid-Open No. 09-145937 [Patent Literature 2] Japanese Patent Laid-Open No. 2010-146771 [Patent Literature 3] Japanese Patent Laid-Open No. 2012-216528 [Patent Literature 4] ] Japanese Patent Laid-Open No. 2012-178345

[Problems to be Solved by the Invention] For such a surface light-emitting device, further improvement in energy efficiency is required, and a technology is required in which light supplied from a light source to a light guide substrate is further efficiently and sufficiently extracted to a light exit surface side of the light guide substrate.

Therefore, several aspects of the present invention provide a composition for a light guide plate by solving at least a part of the problem, and the composition for a light guide plate can be manufactured to be capable of uniformly emitting light to light emission with higher brightness. The light guide plate on the surface side is also excellent in storage stability.

[Means for Solving the Problems] The present invention has been made to solve at least a part of the problems, and can be implemented as the following aspects or application examples.

[Application Example 1] One aspect of the composition for a light guide plate of the present invention contains light diffusing particles (A) and a dispersion medium (B), and the composition for a light guide plate is characterized by being produced using the composition: The formed film with a thickness of 10 μm has a reflectance of 0% to 50% at a wavelength of 300 nm to 380 nm, and a reflectance of 30% to 99% at a wavelength of 400 nm to 800 nm.

[Application Example 2] In the composition for a light guide plate of Application Example 1, the value obtained by dividing the standard deviation of the particle size distribution of the light diffusion particles (A) by the number average particle diameter (coefficient of particle variation) may be 0.01 to 0.2.

[Application Example 3] In the composition for a light guide plate of Application Example 1 or Application Example 2, the ratio (Rmax / Rmin) of the major axis (Rmax) to the minor axis (Rmin) of the light diffusion particles (A) may be 1.01. The range of ~ 1.2.

[Application Example 4] The composition for a light guide plate according to any one of Application Examples 1 to 3 may include a photopolymerizable component as the dispersion medium (B).

[Application Example 5] The composition for a light guide plate of any one of Application Examples 1 to 4 may further contain a radical scavenger (C).

[Application Example 6] The composition for a light guide plate of any one of Application Examples 1 to 5 may further contain an isothiazoline compound.

[Application Example 7] One aspect of the light guide plate of the present invention is characterized in that it is produced using the composition for a light guide plate of any one of Application Examples 1 to 6.

[Effects of the Invention] According to the composition for a light guide plate of the present invention, a light diffusion portion is formed by applying the composition to a light guide substrate, so that light can be uniformly emitted to the light exit surface side with higher brightness. Light guide. In addition, the composition for a light guide plate of the present invention is also excellent in storage stability.

Hereinafter, preferred embodiments of the present invention will be described in detail. In addition, it should be understood that the present invention is not limited to only the following embodiments, and various modifications that are implemented without changing the gist of the present invention are also included. The "(meth) acrylic acid" in the present specification is a concept including both "acrylic acid" and "methacrylic acid". The "~ (meth) acrylate" is a concept including both "~ acrylate" and "~ methacrylate". The "(meth) acrylfluorenyl group" is a concept including both "acrylfluorenyl" and "methacrylfluorenyl".

In addition, in this specification, the light diffusing particle (A) may be simply used as "(A) component", the dispersion medium (B) may be simply used as "(B) component", and a radical scavenger ( C) It is used briefly as "(component C)".

1. Composition for Light Guide Plate The composition for a light guide plate (hereinafter, also simply referred to as a "composition") of the present embodiment is a composition used to form a light diffusion portion of a light guide plate. The composition for a light guide plate according to this embodiment contains light diffusion particles (A) and a dispersion medium (B).

A 10 μm-thick cured film made using the composition for a light guide plate according to this embodiment has a reflectance of 0% to 50% at a wavelength of 300 nm to 380 nm, and a reflectance of 30 at a wavelength of 400 nm to 800 nm. % To 99%. That is, it is clear that by including the light-diffusing particles (A) described later in the cured film, ultraviolet light is easily absorbed and visible light is easily reflected.

If the reflectance of the cured film at the wavelength of 300 nm to 380 nm is in the above range, when the photopolymerizable component is contained in the dispersion medium (B), ultraviolet light is easily absorbed, and thus the cured film is cured. Sex tends to be good. On the other hand, if the reflectance of the cured film at a wavelength of 400 nm to 800 nm is within the above range, visible light is easily reflected homogeneously, and uneven brightness or chromaticity caused by reflected light can be effectively suppressed. Both. Therefore, according to the composition for a light guide plate according to this embodiment, a light guide plate having excellent surface light emission homogeneity and exhibiting good light emitting characteristics can be produced.

The hardened film having a thickness of 10 μm can be produced according to a method described in Examples described later. In addition, the reflectance at a wavelength of 300 nm to 380 nm and the reflectance at a wavelength of 400 nm to 800 nm are as described in the examples described later, and the obtained cured film having a thickness of 10 μm can be measured by using a spectrophotometer. The obtained reflection spectrum is obtained.

Hereinafter, the components which can be contained in the composition for light-guide plates of this embodiment are demonstrated in detail.

1.1. Light diffusing particles (A) As the light diffusing particles (A), inorganic particles or organic particles can be used. As the inorganic particles, calcium carbonate particles, barium sulfate particles, titanium dioxide particles, and the like can be preferably used. As the organic particles, core-shell type organic particles, hollow organic particles, and irregularly shaped organic particles having a non-spherical shape can be preferably used. The light-diffusing particles (A) used in the present invention may be used alone or in combination of two or more.

When the number average particle diameter (Dn) of such light diffusion particles (A) is an organic particle, it is preferably 0.3 μm to 2 μm, and more preferably 0.4 μm to 1.8 μm. On the other hand, when the light diffusion particle (A) is an inorganic particle, it is preferably 0.5 μm to 3 μm, and more preferably 0.8 μm to 2.8 μm. The number-average particle diameter (Dn) of the light-diffusing particles (A) can be measured by using a particle size distribution measuring device using a dynamic light scattering method as a measuring principle.

The so-called "number average particle diameter measured by dynamic light scattering method" refers to the observation of fluctuations in the intensity of scattered light by using a particle size distribution measuring device based on the measurement principle of dynamic light scattering method, and obtained by the photon correlation method The auto-correlation function is a number average particle size obtained by analysis using a cumulant method and a histogram method.

Examples of the particle size distribution measurement device based on the dynamic light scattering method include: Nano particle analyzer "Delsa Nano" manufactured by Beckman-coulter, and Malvern "Zetasizer nano zs" manufactured by (Malvern) company, "ELSZ-1000ZS" manufactured by Otsuka Electronics Co., Ltd., etc.

The inorganic particles whose number average particle diameter (Dn) is within the above range can be obtained by appropriately selecting from commercially available products based on the particle size distribution. In addition, core-shell particles, hollow particles, irregular particles, and the like can be produced by a method described in International Publication No. 2005/071014 or Japanese Patent Laid-Open No. 2013-93205.

The particle variation coefficient (coefficient of variation (CV) value) of the light diffusion particles (A) contained in the composition for a light guide plate according to this embodiment is preferably in a range of 0.01 to 0.2, and more preferably in a range of 0.02 to 0.15. range. It is clear that light must be uniformly diffused to the light exit surface side in the light guide plate, and if the particle variation coefficient of the light diffusion particles (A) is within the above range, the degree of distribution of the particle diameter can be formed to make the light homogeneous. Ground diffusion and reduce diffuse reflection of light. As a result, the light extraction efficiency of the light guide plate is dramatically improved.

The particle variation coefficient (CV value) can be obtained by the following formula (1). CV value = standard deviation (σ) of particle size distribution / number average particle size (Dn) ... (1)

The ratio (Rmax / Rmin) of the major axis (Rmax) to the minor axis (Rmin) of the light diffusion particle (A) is preferably in the range of 1.01 to 1.2, and more preferably in the range of 1.02 to 1.15. If the ratio (Rmax / Rmin) is within the above range, the surface area of the light diffusing particles (A) increases and the surface of the light diffusing particles (A) becomes a non-spherical curved surface. Therefore, the light scattering efficiency becomes large, and the light guide plate The average brightness becomes larger.

The long diameter (Rmax) of the light-diffusing particles (A) refers to the distance between the longest straight line of the end of the image and the straight line connecting the ends of the image in an independent light-diffusing particle image taken with a transmission electron microscope. The short diameter (Rmin) of the light diffusion particle (A) refers to the distance between the end of the image and the shortest straight line in the end of the image in an independent light diffusion particle image taken with a transmission electron microscope.

For example, when an image of an independent light diffusion particle 40a taken by a transmission electron microscope as shown in FIG. 3 has an elliptical shape, the major axis a of the elliptical shape is determined as the long diameter of the light diffusion particle. (Rmax), and the short axis b is determined as the short diameter (Rmin) of the light diffusion particle. As shown in FIG. 4, when the image of one independent light diffusing particle 40 b taken by a transmission electron microscope is an aggregate of two primary particles, the longest of the straight lines connecting the end of the image and the end is The distance c is determined as the long diameter (Rmax) of the light diffusion particle, and the shortest diameter d of the straight line connecting the end portion of the image and the end portion is determined as the short diameter (Rmin) of the light diffusion particle. As shown in FIG. 5, when an image of an independent light diffusing particle 40 c taken by a transmission electron microscope is an aggregate of three or more primary particles, an end portion of the image is connected to a straight line of the end portion. The longest distance e is determined as the long diameter (Rmax) of the light diffusion particle, and the shortest diameter f of the straight line connecting the end portion of the image and the end portion is determined as the short diameter (Rmin) of the light diffusion particle.

The determination method can be used, for example, measuring the major axis (Rmax) and minor axis (Rmin) of 20 light diffusing particles (A), calculating the average value of major axis (Rmax) and minor axis (Rmin), and then calculating The ratio (Rmax / Rmin) of the average value of the long axis and the average value of the short axis was obtained.

The light-diffusing particles (A) may be, for example, a “shaped particle” having a structure in which the first light-diffusing particles and the second light-diffusing particles are in close contact. In this case, the light-diffusing particles (A) may have a structure in which at least a part of the surface of any one type of light-diffusing particles (A) is provided with another type of light-diffusing particles (A). Herein, the term "heteromorphic" as used herein means that two particles are arranged asymmetrically with respect to the center point of the entire particle.

6 to 11 are explanatory diagrams schematically showing the concept of the irregular particles. Examples of the “heteromorphic particles” include structures as shown in FIGS. 6 to 11.

The special-shaped particle 50 a shown in FIG. 6 has a structure in which the second light diffusion particle 54 a is in close contact with a part of the surface of the first light diffusion particle 52 a, and the second light diffusion particle 54 a projects from the surface of the first light diffusion particle 52 a.

The special-shaped particle 50b shown in FIG. 7 includes that the second light diffusion particle 54b is completely contained inside the first light diffusion particle 52b, and the second light diffusion particle 54b is in contact with one point on the surface of the first light diffusion particle 52b and is integrated. A roughly spherical structure.

The special-shaped particle 50c shown in FIG. 8 has a structure in which the first light diffusion particle 52c and the second light diffusion particle 54c are in close contact and have a substantially spherical shape as a whole. In the deformed particles 50c shown in FIG. 8, the first light diffusion particles 52c and the second light diffusion particles 54c have the same surface area, and there is no particular limitation in this regard.

The special-shaped particle 50d shown in FIG. 9 has the second light-diffusion particle 54d included in the first light-diffusion particle 52d, and the curved surface of the second light-diffusion particle 54d appears on the surface of the special-shaped particle 50d and has a substantially spherical shape as a whole. structure.

The abnormal particle 50e shown in FIG. 10 has a structure in which the abnormal particle 50c shown in FIG. 8 has a rugby-like elliptical shape as a whole. In the deformed particles 50e shown in FIG. 10, the first light diffusion particles 52e and the second light diffusion particles 54e have the same surface area, and there is no particular limitation in this regard.

The special-shaped particle 50f shown in FIG. 11 has a structure in which the first spherical light diffusion particle 52f and the second spherical light diffusion particle 54f in a substantially spherical shape are in close contact with each other and have a twin spherical shape as a whole.

When the shaped particle is an organic particle, it is not particularly limited, and it is preferably composed of two particles, the first light diffusion particle and the second light diffusion particle. In this case, the composition of the first light diffusing particle may be the same as or different from the composition of the second light diffusing particle, and it is preferably at least one kind of single-body unit contained in the first light diffusing particle and the second light diffusing particle. The singular body units contained in them are different. That is, in this case, at least one of the unitary body units constituting the irregular-shaped organic particles is included only in any one of the first light diffusion particles and the second light diffusion particles. Thereby, as shown in FIG. 6 to FIG. 11, the first light diffusion particles and the second light diffusion particles can be separated asymmetrically.

When the light-diffusing particle (A) is a special-shaped particle, the major and minor diameters of the special-shaped particle are measured as follows in the point that the special-shaped particle essentially constitutes one particle. For example, when the light-diffusing particles (A) are substantially spherical particles 50a having spherical protrusions as shown in FIG. 6, the major axis (Rmax) ranges from the end of the first light-diffusing particles 52a to the second The distance to the end of the light diffusion particle 54a is shown. The short diameter (Rmin) is represented by the diameter of a larger particle (the first light diffusion particle 52 a in FIG. 6).

When the light diffusion particle (A) is a special-shaped particle and the special-shaped particle is an organic particle, it can be produced, for example, by a method described in Japanese Patent Laid-Open No. 2013-098123. When the irregular particles are inorganic particles, they can be produced by a known method such as a pulverization method and a classification operation after pulverization.

The absolute value | Δn | of the refractive index difference between the light-diffusing particles (A) and a photopolymerizable component described later after polymerization is preferably 0.02 ≦ | Δn | ≦ 1.3. For example, when using a photopolymerizable monomer or a photopolymerizable oligomer as the photopolymerizable component, if calcium carbonate particles (refractive index: n = 1.59), barium sulfate particles (refractive index: n = 1.64), and titanium dioxide particles are used At least one of (refractive index: n = 2.7) is satisfied as the light diffusion particle (A).

The composition for a light guide plate according to the present embodiment is in a state where the above-described light-diffusing particles (A) are dispersed in a dispersion medium (B). Content of the light-diffusion particle (A) in the composition for light-guide plates of this embodiment, when the light-diffusion particle (A) is an inorganic particle, when the total mass of a composition is 100 mass%, 0.5 is preferable Mass% to 20% by mass, more preferably 1% to 15% by mass, and particularly preferably 3% to 12% by mass. When the light diffusing particles (A) are organic particles, when the total mass of the composition is 100% by mass, it is preferably 0.5% to 40% by mass, and more preferably 5% to 35% by mass. It is particularly preferably 10% by mass to 30% by mass. When the content of the light diffusing particles (A) is within the above range, the storage stability of the composition becomes good and the coatability of the composition becomes good. Therefore, it is easy to form a homogeneous light diffusing portion on the surface of the light guide substrate. .

1.2. Dispersion medium (B) The composition for a light guide plate of this embodiment contains a dispersion medium (B). When a light-diffusion part is produced using the composition for light-hardening-type light-guide plates, it is preferable to use a photopolymerizable component as a dispersion medium (B). By using a photopolymerizable component, generation of voids in a light diffusion portion described later can be suppressed, and diffuse reflection due to generation of voids can be further suppressed. Such a photopolymerizable component preferably has a photopolymerizable functional group such as a vinyl group, and preferably uses a photopolymerizable monomer or a photosensitive polymer. As such a component, for example, a compound described in International Publication No. 2005/071014 or Japanese Patent Laid-Open No. 2013-93205 can be used as appropriate.

Examples of the photopolymerizable monomer include an aromatic vinyl group, an unsaturated nitrile, an unsaturated carboxylic acid ester, and an unsaturated amidine.

Examples of the aromatic vinyl group include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, P-ethylstyrene, p-third butylstyrene, m-divinylbenzene, p-divinylbenzene, m-diisopropenylbenzene, p-diisopropenylbenzene, o-chlorostyrene, m-chlorostyrene, P-chlorostyrene, 1,1-diphenylethylene, p-methoxystyrene, N, N-dimethyl-p-aminostyrene, N, N-diethyl-p-aminostyrene, 2 -Vinylpyridine, 3-vinylpyridine, 4-vinylpyridine and the like.

Examples of unsaturated nitriles include (meth) acrylonitrile, α-chloroacrylonitrile, α-chloromethacrylonitrile, α-methoxyacrylonitrile, α-ethoxyacrylonitrile, and butyronitrile , Cinnamic acid nitrile, itaconic acid dinitrile, maleic acid dinitrile, fumaric acid dinitrile, etc.

Examples of the unsaturated carboxylic acid esters include (meth) acrylates; butyryl esters such as methyl butenoate, ethyl butenoate, propyl butyrate, and butyl butyrate; and methyl cinnamate Esters, cinnamic acid esters, cinnamic acid propyl, cinnamic acid esters and the like. Among these, a (meth) acrylate is preferable.

Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid N-butyl ester, isobutyl (meth) acrylate, second butyl (meth) acrylate, third butyl (meth) acrylate, n-amyl (meth) acrylate, n-octyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-methyl (meth) acrylate (Meth) acrylates such as ethoxyethyl ester, 2- (n-propoxy) ethyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate , 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, [4- (hydroxymethyl) cyclohexyl] methyl (meth) acrylate, 2-hydroxy (meth) acrylate Hydroxy-containing (meth) acrylates such as 3-phenoxypropyl esters; (meth) acrylic acid monoesters of polyalkylene glycols such as polyethylene glycol and polypropylene glycol;

Cyano-containing (meth) acrylates such as cyanoethyl (meth) acrylate and cyanopropyl (meth) acrylate; 2-phenoxyethyl (meth) acrylate, (meth) acrylic acid Aryloxy (meth) acrylates such as 2-phenoxypropyl, 3-phenoxypropyl (meth) acrylate; methoxy polyethylene glycol, ethoxy polyethylene glycol, methyl (Meth) acrylic acid monoesters of alkoxy polyalkylene glycols such as oxypolypropylene glycol and ethoxy polypropylene glycol; aryloxy polyalkylene glycols such as phenoxy polyethylene glycol and phenoxy polypropylene glycol (Meth) acrylic acid monoesters; (A) of alkanediols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol Group) acrylic acid diesters; (meth) acrylic acid diesters of polyalkylene glycols such as polyethylene glycol and polypropylene glycol (the number of alkanediol units is, for example, 2 to 23), two terminal hydroxyl polybutadienes, and two terminal hydroxyl groups (Meth) acrylic acid diesters of polymers having hydroxyl groups at both ends, such as polyisoprene, hydroxybutadiene-acrylonitrile copolymers at both ends, and polycaprolactone at both ends; glycerol, 1, 2, 4- Butanetriol, trimethylol alkane (carbon of alkane The number is, for example, 1 to 3), a tetramethylol alkane (the carbon number of the alkane is, for example, 1 to 3), a (meth) acrylic acid diester of a trivalent or higher polyhydric alcohol such as pentaerythritol, and a (meth) acrylic acid triester Or (meth) acrylic oligopolyesters such as (meth) acrylic acid tetraesters; (meth) acrylic acid triesters or (meth) acrylic acid tetraesters such as polyalkylene glycol adducts of polyvalent alcohols of trivalent or higher ( (Meth) acrylic oligoesters and the like.

Examples of the unsaturated fluorenamine include (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N, N-bis (2-hydroxyethyl) (meth) acrylamide, N, N'-methylenebis (meth) acrylamide, N, N'-ethylidenebis (meth) acrylamine Amines, N, N'-hexamethylenebis (meth) acrylamidoxamine, acrylamidomorpholine, butenamide, cinnamidine and the like.

As a photosensitive polymer, if a photopolymerizable group is introduce | transduced into a polymer skeleton, a well-known thing can be used without a restriction | limiting. Examples of such a polymer skeleton include a polyether skeleton, a polyurethane skeleton, a polyethylene skeleton, a polyester skeleton, a polyimide skeleton, a polyimide skeleton, a polyphenylene skeleton, and the like, and a polyphenylene skeleton is preferred. Ether skeleton, polyurethane skeleton. Examples of the photopolymerizable group include a (meth) acrylfluorenyl group, an alkenyl group, a cinnamoyl group, a phenallylethylethyl group, a phenylmethyleneacetophenone group, and a styrylpyridyl group , Α-phenylmaleimide, phenylazide, sulfoazide, carbonylazide, diazo, o-quinonediazide, furylpropenyl, coumarol Sulfonyl, pyranone, anthracenyl, benzophenone, benzoin, distyryl, dithiocarbamate, xanthate, 1,2,3-thiadiazole Group, cyclopropenyl group, azadioxabicyclo group, and the like, preferred photopolymerizable groups are (meth) acrylfluorenyl and cinnamylfluorenyl, and particularly preferably (meth) acrylfluorenyl.

Furthermore, by adding an aliphatic urethane (meth) acrylate as the dispersion medium (B), it is possible to easily control the viscosity or photocurability of the composition for a light guide plate.

The dispersion medium (B) used in the present invention may be used alone or in combination of two or more.

When the dispersion medium (B) contains a photopolymerizable component, when the total mass of the composition is 100% by mass, the content of the photopolymerizable component in the composition for a light guide plate of the present embodiment is preferably 50 mass % To 95% by mass, and more preferably 60% to 80% by mass. When the content of the photopolymerizable component is within the above range, the light diffusion particles (A) contained in the light diffusion portion formed on the surface of the light guide substrate can be held with sufficient strength, and the light diffusion in the manufacturing step can be effectively suppressed. The particles (A) are peeled off, etc., and foreign matter is generated.

1.3. Radical Scavenger (C) The composition for a light guide plate according to the present embodiment may contain a radical scavenger (C). By containing a radical scavenger (C), it is possible to effectively prevent the polymerization of the photopolymerizable components of the composition for a light guide plate during the storage stage, and to suppress unevenness in brightness or unevenness in the light diffusion portion and improve the light guide plate. Homogeneity of surface luminescence.

When the content of the light diffusing particles (A) in the composition is Ma parts by mass and the content of the radical scavenger (C) is Mc parts by mass, the ratio Ma / Mc of the two is preferably 20 to 500, and more It is preferably 30 to 300. It is clear that by using the radical scavenger (C) within the above range, it is possible to effectively prevent the polymerization of the photopolymerizable component of the composition for a light guide plate during the storage stage, and to suppress uneven brightness or unevenness in the light diffusion portion. The chromaticity is uneven and the surface light emission uniformity of the light guide plate is further improved.

The discovery mechanism of containing the radical scavenger (C) to suppress the uneven brightness or uneven chromaticity of the light diffusion portion and further improve the uniformity of the surface light emission of the light guide plate is not clear, but it can be considered as follows .

When the composition for a light guide plate is used, the composition for a light guide plate is always exposed to oxygen-containing external air or the like. For example, in a case where the light diffusion portion is produced by printing, a certain period of time is required from the start to the end of printing on the light guide substrate. Thereafter, a hardening step such as light irradiation is performed on the printed composition for a light guide plate to produce a light diffusion portion. At this time, the light-diffusion part precursor part (referred to as the light-guide plate composition printing part which has been hardened to become the light-diffusion part before the initial printing) is formed before the light-diffusion part precursor part at the end of printing before the curing step. Longer exposure to the atmosphere. It is considered that the difference in the amount of oxygen absorbed from the atmosphere by the light diffusing portion precursor portion due to the difference in the exposure time of the atmosphere. As a result, it is presumed that the hardened state of the composition for a light guide plate undergoes some change in the subsequent hardening step. It is estimated that the difference in the hardened state is a difference in the light diffusion state of each light diffusion portion, and promotes deterioration in the uniformity of surface light emission of the light guide plate.

However, when the composition for a light guide plate contains a radical scavenger (C), even if the amount of oxygen absorbed from the atmosphere differs during the air exposure time, as a result, the initial stage and the later stage of the production of the light diffusing section precursor section are different. The amount of oxygen contained in the precursor portion of the light diffusion portion varies, and the amount of oxygen radicals generated by the absorbed oxygen during the subsequent hardening process varies. The radical scavenger (C) can also capture these and suppress them. These actions. As a result, it is presumed that the light diffusion portion precursor portion having a more homogeneous composition can be hardened, and the surface light emission uniformity of the light guide plate can be further improved.

As a radical scavenger (C), a phenol derivative is preferable, for example. By using a phenol derivative, the whiteness of a light-diffusion part is further improved. Examples of the phenol derivative include hydroquinone, hydroquinone monomethyl ether, mono-tert-butylhydroquinone, catechol, 4-tert-butylcatechol, and hydroquinone Hydroxy aromatic compounds such as oxyphenol, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-m-cresol, catechol, β-naphthol, benzoquinone , 2,5-diphenyl-p-benzoquinone, p-methylquinone, p-xyloquinone, etc. The radical scavenger (C) used in the present invention may be used alone or in combination of two or more.

When the total mass of the composition is 100% by mass, the content of the phenol derivative as the radical trapping agent (C) in the composition for a light guide plate of the present embodiment is preferably 0.001% to 2% by mass, more It is preferably 0.01% by mass to 1% by mass, and particularly preferably 0.05% by mass to 0.5% by mass. When the content of the phenol derivative as the radical scavenger (C) is within the above range, the polymerization of the photopolymerizable component in the storage stage of the composition for a light guide plate can be effectively prevented. Moreover, the whiteness of a light-diffusion part can be improved further.

1.4. Photopolymerization Initiator The composition for a light guide plate of the present embodiment may contain a photopolymerization initiator. In particular, when the dispersion medium (B) is a photopolymerizable component, it is preferable to contain a photopolymerization initiator in order to improve photocurability.

As such a photopolymerization initiator, it can be appropriately selected by users generally in the field of radiation-curable resins, and examples thereof include compounds described in International Publication No. 2005/071014 or Japanese Patent Laid-Open No. 2013-93205. .

Specific examples of the photopolymerization initiator include α-diketone compounds such as diethylpyrene, methyl benzamate, benzoin, and acyloin such as benzoin and pivaloin; Ether ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; polynuclear quinones such as anthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1,4-naphthoquinone Class; acetophenone, 2-hydroxy-2-methyl-phenylacetone, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxyphenylacetophenone, 2,2-diethoxybenzene Acetophenones such as ethyl ketone, trichloroacetophenone; benzophenones, such as benzophenone, methyl benzophenone benzoate, Michler's ketone; xanthone, thioxanthone Xanthones such as ketones and 2-chlorothioxanthone. The photopolymerization initiator used in the present invention may be used alone or in combination of two or more.

When the total mass of the composition is 100% by mass, the content of the photopolymerization initiator in the composition for a light guide plate of the present embodiment is preferably 0.1% to 20% by mass, and more preferably 0.5% to 10% by mass. %. When the content of the photopolymerization initiator is within the above range, a tack-free light diffusion portion can be produced in order to improve the photocurability of the composition for a light guide plate.

1.5. Other Components The composition for a light guide plate according to the present embodiment may further contain components other than the above components, such as an isothiazoline-based compound, a phosphate ester, a surfactant, water, an adhesive, and the like.

<Isothiazoline-based compound> By adding an isothiazoline-based compound to the composition for a light guide plate of the present embodiment, the isothiazoline-based compound acts as a preservative, and it can be suppressed when the composition for a light guide plate is stored. Bacteria or molds multiply and produce foreign bodies. Furthermore, it became clear that unevenness in brightness or chromaticity in the light diffusion portion can be suppressed, and the uniformity of surface light emission of the light guide plate can be further improved.

The discovery mechanism of the effect of suppressing the uneven brightness or uneven chromaticity of the light diffusion portion and further improving the uniformity of the surface light emission of the light guide plate by containing the isothiazoline-based compound is not clear, but it can be considered as follows. When the composition for a light guide plate is used, the composition for a light guide plate is always exposed to oxygen-containing external air or the like. For example, in a case where the light diffusion portion is produced by printing, a certain period of time is required from the start to the end of printing on the light guide substrate. Thereafter, a hardening step such as light irradiation is performed on the printed composition for a light guide plate to produce a light diffusion portion. At this time, the light-diffusion part precursor part (referred to as the light-guide plate composition printing part which has been hardened to become the light-diffusion part before the initial printing) is formed before the light-diffusion part precursor part at the end of printing before the curing step. Longer exposure to the atmosphere. It is considered that the difference in the amount of volatile organic substances absorbed from the atmosphere by the light diffusing portion precursor portion due to the difference in the exposure time of the atmosphere. As a result, it is presumed that the hardened state of the composition for a light guide plate undergoes a certain change in the subsequent hardening step, and the difference in the hardened state becomes a difference in the light diffusion state of each light diffusing portion, which promotes homogeneity of the surface light emission of the light guide plate. Sexual degradation.

On the other hand, in the composition for a light guide plate according to this embodiment, the isothiazoline-based compound tends to be held by being adsorbed to the light diffusion particles (A) and the like. As a result, it is considered that the surface of the light diffusion particle (A) is protected by the isothiazoline-based compound, and it is considered that the adsorption of the volatile organic substance absorbed from the atmosphere on the surface of the light diffusion particle (A) is suppressed. As a result, even if there is a difference in the amount of volatile organic compounds contained in the light diffusing section precursors at the initial stage and the post-production stage of the light diffusing section precursors, these volatile organic substances are not firmly adsorbed on the surface of the light diffusing particles (A) . It is presumed that the above-mentioned action prevents the light diffusion portion from being held in the light diffusion portion in the subsequent hardening step and releases it into the atmosphere again. Therefore, the light diffusion portion precursor portion having a more homogeneous composition can be hardened, and the surface of the light guide plate can be further improved. Luminous homogeneity.

The isothiazoline-based compound is not particularly limited as long as it is a compound having an isothiazoline skeleton, and examples thereof include a compound represented by the following general formula (2) or a compound represented by the following general formula (3).

[Chemical 1]

In the general formula (2), R ¹ is a hydrogen atom or a hydrocarbon group, and R ² and R ³ each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group. When R ¹ , R ² , and R ³ are hydrocarbon groups, they may have a linear carbon skeleton such as a straight chain or a branched chain, or may have a cyclic carbon skeleton. The carbon number of the hydrocarbon group is preferably 1 to 12, more preferably 1 to 10, and particularly preferably 1 to 8. Specific examples of such a hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, hexyl, cyclohexyl, octyl, 2-ethylhexyl, and the like.

[Chemical 2]

In the general formula (3), R ⁴ is a hydrogen atom or a hydrocarbon group, and R ⁵ each independently represents a hydrogen atom or an organic group. When R ⁴ is a hydrocarbon group, the same hydrocarbon group as the hydrocarbon group described in the general formula (2) can be mentioned. When R ⁵ is an organic group, the organic group contains an aliphatic group or an aromatic group as an alkyl group or a cycloalkyl group, and is preferably an aliphatic group. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 10, and particularly preferably 1 to 8. These alkyl groups and cycloalkyl groups may have a substituent such as a halogen atom, an alkoxy group, a dialkylamino group, a fluorenyl group, and an alkoxycarbonyl group. Specific examples of the aliphatic group include methyl, ethyl, propyl, isopropyl, butyl, hexyl, cyclohexyl, octyl, and 2-ethylhexyl. In the formula (3), n represents an integer of 0 to 4.

Specific examples of the isothiazoline-based compound include 1,2-benzoisothiazolin-3-one, 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, and 2 -Methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, N-n-butyl-1,2-benzoisothiazolin-3 -Ketone, 2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, etc., one or both of these can be used More than that. Among these, 2-methyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, and 5-chloro-2-methyl-4-isothiazole are preferred. Phenolin-3-one, 1,2-benzoisothiazolin-3-one.

When the total mass of the composition is 100% by mass, the content of the isothiazoline compound in the composition for a light guide plate of the present embodiment is preferably 0.01% by mass to 0.5% by mass, and more preferably 0.015% by mass to 0.2. The mass% is particularly preferably 0.01 to 0.1 mass%. By using the isothiazoline-based compound within the above range, the storage stability of the composition for a light guide plate can be improved.

When the content of the light diffusing particles (A) in the composition is Ma parts by mass and the content of the isothiazoline-based compound is Md parts by mass, the ratio Ma / Md between the two is preferably 50 to 600. The ratio is more preferably 100 to 500. It is clear that by using an isothiazoline-based compound within the above range, the storage stability of the composition for a light guide plate can be improved, and unevenness in brightness or chromaticity of the light diffusion portion can be suppressed and the light guide plate can be further improved. Surface light emission homogeneity.

<Phosphate ester> By adding a phosphate ester to the composition for a light-guide plate of this embodiment, the adhesiveness of a light-guide board and a light-diffusion part can be improved. In addition, it is possible to improve the balance between hardness, scratch resistance, abrasion resistance, and low curl when the composition for a light guide plate is made into a cured coating film.

The phosphate is preferably a compound represented by the following general formula (4). In addition, even in a case where the phosphate ester corresponds to a photopolymerizable component, the phosphate ester and the dispersion medium (B) are regarded as different components in the present invention.

（式（4）中，R⁶ 表示氫原子或甲基，R⁷ 表示二價有機基，n表示1或2的整數）。[Chemical 3]

(In formula (4), R ⁶ represents a hydrogen atom or a methyl group, R ⁷ represents a divalent organic group, and n represents an integer of 1 or 2).

Examples of the phosphate include mono (2- (meth) acryloxyethyl) phosphate, bis (2- (meth) acryloxyethyl) phosphate, and mono (2- (methyl) ) Acryloxypropyl) phosphate or bis (2- (meth) acryloxypropyl) phosphate, mono (3- (meth) acryloxypropyl) phosphate or bis ( 3- (meth) acryloxypropyl) phosphate, mono (6- (meth) acryloxyhexyl) phosphate or bis (6- (meth) acryloxyhexyl) phosphate, Mono (10- (meth) acryloxydecyl) phosphate or bis (10- (meth) acryloxydecyl) phosphate, mono (1-chloromethyl-2- (methyl) Acrylic ethoxyethyl) phosphate or bis (1-chloromethyl-2- (meth) acrylic ethoxyethyl) phosphate, 2- (meth) acrylic ethoxyethylphenyl phosphate And the like, and lactone-modified products, polyoxyalkylene-modified products of these phosphate esters, and the like. Among these, mono (2- (meth) acryloxyethyl) phosphate or bis (2- (Meth) acryloxyethyl) phosphate. The phosphate used in the present invention may be used singly or in combination of two or more kinds.

Examples of commercially available phosphate esters include trade names manufactured by Kyoeisha Chemical Co., Ltd .: Light Ester P-1M, P-2M, and trade names manufactured by Nippon Kayaku Co., Ltd .: Kaya KAYAMER PM-2, PM-21, etc.

When the total mass of the composition is 100% by mass, the content of the phosphate ester in the composition for a light guide plate according to this embodiment is preferably 0.07 to 5% by mass, and more preferably 0.2 to 2% by mass.

<Surfactant> By adding a surfactant to the composition for a light guide plate of this embodiment, the surface tension of the composition for a light guide plate or the wettability of a light guide substrate can be controlled. The surfactant is not particularly limited, and a silicon-based surfactant and a fluorine-based surfactant are preferred.

When the total mass of the composition is 100% by mass, the content of the surfactant in the composition for a light guide plate of the present embodiment is preferably 0.01% by mass to 2% by mass, and more preferably 0.05% by mass to 1% by mass. .

<Water> By adding water to the composition for a light guide plate of this embodiment, the storage stability of the composition for a light guide plate may improve.

When the total mass of the composition is 100% by mass, the content of water in the composition for a light guide plate of the present embodiment is preferably 0.5% by mass or less, and more preferably 0.01% by mass to 0.4% by mass.

In addition, since the inorganic particles generally have a large surface area and a hydrophilic surface, they tend to easily absorb moisture. On the other hand, the organic particles have a smaller surface area than the inorganic particles and the surface is hydrophobic, so that moisture adsorption can be suppressed. Therefore, in order to strictly control the amount of water in the composition for a light guide plate, the light-diffusing particles (A) are preferably organic particles.

<Adhesive> By adding an adhesive to the composition for a light-guide plate of this embodiment, the adhesiveness of a light-guide board and a light-diffusion part can be improved. The binder is not particularly limited, and the binder described in International Publication No. 2005/071014 or Japanese Patent Laid-Open No. 2013-93205 can be used.

2. Light guide plate The light guide plate of this embodiment is characterized by being produced using the composition for a light guide plate. Specifically, the light guide plate composition is coated or printed on a light guide substrate having a surface roughness Ra <1 nm to produce a light diffusion portion.

FIG. 1 is a cross-sectional view showing a transmissive image display device including a light guide plate according to an embodiment of the present invention. The transmissive image display device 100 shown in FIG. 1 is mainly composed of a surface light source device 20 and a transmissive image display section 30. The surface light source device 20 is an edge-emission type surface light source device including a light guide plate 1 and a light source 3. The light guide plate 1 includes a light guide substrate 11 and a light diffusing portion 12. The light source 3 is provided on the side of the light guide plate 1 and faces the light guide plate 1. The light guide plate 1 supplies light. In addition, the light-diffusion part 12 is a several dot shape in FIG.

The light guide substrate 11 has a substantially rectangular parallelepiped shape, and has an exit surface S1, an exit surface S2 opposite to the exit surface S1, and four end faces S3 ₁ to S3 _{4 that} intersect the exit surface S1 and the exit surface S2. In this embodiment, the four end faces S3 ₁ to S3 _{4 are} substantially orthogonal to the emission surface S1 and the emission surface S2.

The light guide plate 1 includes a plurality of light diffusion portions 12 provided on the emission surface S2 side. As shown in FIG. 2, the plurality of light diffusing portions 12 are spaced apart from each other on the emission surface S2. FIG. 2 is a plan view when the light guide substrate is viewed from the emission surface S2 side. In FIG. 2, for convenience of explanation, the light source 3 is also shown together. In FIG. 2, the light diffusion portions 12 are arranged separately from each other. The number and arrangement pattern of the light diffusing portions 12 are adjusted so that uniform planar light can be efficiently emitted from the emission surface S1 or if necessary, from the emission surface S2.

The light source 3 is disposed on a side of a pair of end surfaces S3 ₁ and S3 ₂ facing each other as shown in FIGS. 1 and 2. As shown in FIG. 2, a plurality of point-shaped light sources are arranged along two opposite sides of the light guide substrate 11, for example, four sides constituting a rectangular emission surface S2.

In the above configuration, light output from the light source 3 enters the light guide substrate 11 from the end faces S3 ₁ and S3 ₂ . The light incident on the light guide substrate 11 is diffusely reflected in the light diffusing portion 12. The shape of the light diffusing portion 12 may be adjusted so that uniform planar light can be efficiently emitted from the exit surface S1 or the exit surface S2. For example, in the case of FIG. 1, the light emitted from the emission surface S1 is supplied to the transmissive image display unit 30.

Hereinafter, members constituting the light guide plate and a method of manufacturing the light guide plate will be described in detail.

2.1. Light guide substrate The light guide plate 1 includes a light guide substrate 11. Considering the light extraction efficiency from the light emitting surface S1 and the light emitting surface S2, it is sufficient if the surface roughness Ra of the light guide substrate 11 is Ra <1 nm, and preferably Ra <0.5 nm. In addition, in consideration of the adhesion between the light diffusion section and the light guide substrate described later, Ra> 0.1 nm is preferable, and Ra> 0.2 nm is more preferable.

In order to suppress the light from the light source from being scattered on the end surface of the light guide substrate, as long as the surface roughness Ra of the end surface of the light guide substrate 11 is 2 μm or less, practically applicable light can be incident from the light source into the light guide substrate 11 .

The "surface roughness Ra" of the light guide substrate 11 of the present invention refers to the "arithmetic average roughness" measured in accordance with Japanese Industrial Standards (JIS) B0601-2001.

Generally, in an edge-emission type surface light-emitting device, when light is generated from a light source, heat is generated, and the temperature of the light guide substrate also rises with this. When a resin plate is used as the light guide substrate, the thermal expansion coefficient of the resin plate is high, so the dimensional change due to heat of the light guide substrate is larger than that of the liquid crystal panel. However, since the bezel of the liquid crystal display device is narrowed, it is difficult to correct the dimensional change of the light guide substrate in the bezel portion of the liquid crystal display device. Therefore, as the material of the light guide substrate 11, a resin plate with small dimensional change due to heat may be used, but a glass substrate is preferred. When the light guide substrate 11 is a glass substrate, the glass substrate has an optical path length of 100 nm and a maximum transmittance at a wavelength range of 350 nm to 750 nm of preferably 50% or more.

The thermal expansion coefficient of the glass substrate is preferably 120 × 10 ^-7 / ° C or lower. When the thermal expansion coefficient exceeds the above range, the difference in dimensional change due to heat between the display panel and the light guide substrate tends to become large. The strain point of the glass substrate is preferably 550 ° C or higher. If the strain point is less than the above range, the heat resistance of the glass substrate is liable to decrease. For example, if a reflective film or a diffusion film is formed on the surface of the glass substrate at a high temperature, the glass substrate is likely to undergo thermal deformation. Here, the "strain point" can be measured based on JIS R3103.

2.1.1. Glass composition The glass composition constituting the glass substrate is preferably 40% to 70% by mass of SiO ₂ , 2% to 25% by mass of Al ₂ O ₃ , and 0% to 20% by mass of B. ₂ O ₃ , 0 to 25% by mass of R ₂ O (R is one or more of Li, Na, K), 0 to 10% by mass of MgO, 0 to 15% by mass of CaO 0% to 10% by mass of SrO, 0% to 15% by mass of BaO, 0% to 10% by mass of ZnO, and 0% to 10% by mass of ZrO ₂ .

SiO ₂ is a component that becomes a network-formed product of glass, and is a component that reduces the thermal expansion coefficient and reduces the dimensional change due to heat. Furthermore, it is a component which improves acid resistance and a strain point. When the content of SiO ₂ is increased, high-temperature viscosity is increased, meltability is reduced, and devitrified substances of cristobalite are easily precipitated during molding. On the other hand, when the content of SiO ₂ decreases, the thermal expansion coefficient tends to increase, and the dimensional change due to heat tends to increase. In addition, acid resistance and strain point are easily reduced.

Al ₂ O ₃ is a component that reduces the thermal expansion coefficient and reduces the dimensional change due to heat. It also has the effect of increasing the strain point and suppressing the devitrification of cristobalite during forming. When the content of Al ₂ O ₃ increases, the liquidus temperature rises, making it difficult to form a glass substrate. On the other hand, if the content of Al ₂ O ₃ decreases, the thermal expansion coefficient tends to increase, and the dimensional change due to heat tends to increase. In addition, the strain point is easily reduced.

B ₂ O ₃ is a component that functions as a flux to reduce high-temperature viscosity and improve meltability. Moreover, it is a component which reduces a thermal expansion coefficient and reduces the dimensional change by heat. When the content of B ₂ O ₃ is within the above range, dimensional change due to heat can be suppressed, and meltability can be improved to improve workability.

R ₂ O is a component that lowers the high-temperature viscosity and improves the meltability. When the content of R ₂ O is within the above range, the strain point can be increased, and the maximum transmittance around the wavelength of 550 nm can be increased.

MgO is a component that does not reduce the strain point but only lowers the high-temperature viscosity and improves the meltability. When the content of MgO is within the above range, it is possible to suppress precipitation of devitrified matter during molding.

CaO is a component that does not reduce the strain point but only lowers the high-temperature viscosity and improves the meltability. When the content of CaO is within the above range, it is possible to suppress precipitation of devitrified matter during molding.

SrO is a component that improves chemical resistance and devitrification resistance. When the content of SrO is within the above range, the thermal expansion coefficient can be reduced, and dimensional changes due to heat can be suppressed.

BaO, like SrO, is a component that improves chemical resistance and devitrification resistance. When the content of BaO is within the above range, the thermal expansion coefficient can be reduced, and dimensional changes due to heat can be suppressed.

ZnO is a component that improves the meltability. When the content of ZnO is within the above range, devitrification resistance can be improved.

ZrO ₂ is a component that increases the strain point. When the content of ZrO ₂ is within the above range, it is possible to suppress precipitation of devitrified matter during molding.

The content of transition metal oxides such as Fe ₂ O ₃ , Cr ₂ O ₃ , V ₂ O ₅ , NiO, MnO ₂ , Nd ₂ O ₃ , CeO ₂ , and Er ₂ O ₃ is preferably 0.1% by mass or less. When the content of the transition metal oxide is too large, the light extraction efficiency may decrease.

In addition to the components described above, other components may be introduced. For example, in order to lower the liquidus temperature, Y ₂ O ₃ , La ₂ O ₃ , Nb ₂ O ₅ , and P ₂ O _{5 can} be introduced up to 3% by mass each. As a clarifying agent, it can be introduced up to 2 in total. Mass% of As ₂ O ₃ , Sb ₂ O ₃ , SnO ₂ , SO ₃ , F, Cl, and the like.

2.1.2. Manufacturing method of glass substrate A glass substrate can be produced by an overflow down-draw method, a slit down-draw method, a float method, a roll out method, a redraw method, and the like. Furthermore, in the float process, temperature difference and composition difference between the front and back surfaces of the glass ribbon are easily generated during molding, but if the temperature during molding is strictly controlled, the temperature difference and composition difference can be reduced. In the overflow down-draw method, temperature difference and composition difference between the front and back surfaces of the glass ribbon are hardly generated during molding, and a glass substrate having a good surface quality is easily formed without polishing.

Furthermore, the glass substrate is applied to a glass substrate used in a display panel, and may also have the function of a light guide substrate at the same time. In this way, the component configuration of the display device can be simplified.

2.2. Light Diffusion Section The light guide plate 1 according to this embodiment includes a light diffusion section 12 containing light diffusion particles (A). The number average particle diameter Dn (nm) of the light diffusing particles (A) is preferably in a relationship of 200 <Dn / Ra <5000, and more preferably 300 <Dn / Ra with respect to the surface roughness Ra (nm) of the light guide substrate 11. <4000. It is considered that if the value of Dn / Ra is within the above range, the interface between the light guide substrate 11 and the light diffusion portion 12 can be prevented from being mixed into the void, and the light extraction efficiency can be improved to achieve uniform surface light emission.

In FIG. 2 described previously, the light diffusing portion 12 has a plurality of substantially circular dot shapes and is arranged separately from each other, but may be adjusted in consideration of the required light extraction efficiency from the exit surface S1 and the exit surface S2 at an appropriate time. Shape etc. The shape of the light diffusing section 12 shown in FIG. 2 is for convenience of explanation, and can be adjusted in consideration of the required light extraction efficiency from the emission surface S1 and the emission surface S2.

The light-diffusion part 12 is manufactured using the said composition for light-guide plates. As a method for forming the light diffusion portion 12 on the light guide substrate 11, a screen printing method, an offset printing method, a spray method of spraying the composition for a light guide plate from a nozzle, or the like can be used for production. For example, a method described in International Publication No. 2005/071014, Japanese Patent Laid-Open No. 2013-93205, Japanese Patent Laid-Open No. 2012-178345, and the like can be used to fabricate the light diffusion portion.

As such a composition for light-guide plates, it is preferable that it is a composition for thermosetting type or a light-hardening type light-guide plate. In order to effectively suppress the deformation of the light guide substrate due to the heat treatment, it is more preferable to use a composition for a light-curable light guide plate to produce a light diffusion portion. It is preferable that the composition for light-guide plates for forming the light-diffusion part 12 is a composition for light-hardening light-guide plates containing a photopolymerizable component and a photoinitiator in the composition for photocurable light-guide plates.

The area of the light diffusion portion 12 is preferably 5% or more and 95% or less with respect to 100% of the area of the light guide substrate 11. As the distance from the light source, the ratio of the planar area occupied by the light diffusing portion 12 on the coating surface of the light guide substrate 11 to the coating area of the composition for a light guide plate or the composition for a light guide plate is preferred. The coating area ratio of the coating area to the coating surface area of the light guide substrate 11 becomes higher. Accordingly, the brightness of the light guide plate can be made substantially uniform.

2.3. Light source The light source 3 is disposed on the side of the end surface S3 ₁ or S3 ₂ as shown in FIGS. 1 and 2. The light source 3 may be a linear light source such as a cold cathode fluorescent lamp (CCFL), but is preferably a point light source such as a light emitting diode (Light Emitting Diode, LED). In this case, as shown in FIG. 2, it is preferable that the light diffusing portions 12 and The light sources 3 are combined.

The configuration, incident light from the light guide 11 from the substrate end face or the end face 3 S3 ₁ outputted from the light source S3 _2. The light incident on the light guide substrate 11 is diffusely reflected or diffused in the light diffusing section 12, and thus is emitted from the exit surface S1 or the exit surface S2. The light emitted from the emission surface S1 or the emission surface S2 is supplied to the transmissive image display unit 30 and the like. In order to efficiently emit uniform planar light from the emitting surface, the number and arrangement pattern of the light diffusion portions 12 can be adjusted in a timely manner.

2.4. Transmissive image display section As shown in FIG. 1, the transmissive image display section 30 is disposed opposite to the light guide plate 1 on the exit surface S1 side of the light guide plate 1, and the light emitted from the exit surface S1 illuminates the transmission type diagram.像 display section 30. As the transmissive image display section 30, for example, a liquid crystal display section having a liquid crystal cell or the like can be used.

3. Examples The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. "Parts" and "%" in Examples and Comparative Examples are based on quality unless otherwise specified.

3.1. Production of light diffusing particles (A) 3.1.1. Production of hollow particles 1 Into a 2 liter reaction vessel, 194 parts of water, 9 parts of methyl methacrylate, and 1 part of methacrylic acid were charged for molecular weight adjustment. 0.92 parts of octyl thioglycolate and 0.04 parts of sodium dodecylbenzenesulfonate as emulsifiers. On the other hand, 71 parts of methyl methacrylate, 19 parts of methacrylic acid, 0.5 parts of octyl thioglycolate, 0.5 parts of sodium dodecylbenzenesulfonate, and 45 parts of water were mixed and stirred to prepare an aqueous monomer mixture. Dispersions.

While stirring the reaction vessel, the temperature was heated to 85 ° C., and 6 parts of a 5% sodium persulfate aqueous solution as a polymerization initiator was charged. Immediately after that, the reaction vessel was stirred while maintaining the temperature at 90 ° C., and the aqueous dispersion of the monomer mixture was charged continuously for 4 hours. The mixture was further aged for 2 hours to obtain an aqueous dispersion of seed particles A having a particle size of 0.200 μm (solid content: 29.3%).

143 parts of water, 10 parts by solid content (34 parts by aqueous dispersion) of the aqueous dispersion of the seed particles A, and 1.2 parts of an 80% acrylic acid aqueous solution were charged into a reaction vessel having a capacity of 2 liters. On the other hand, 77.2 parts of styrene, 0.8 parts of divinylbenzene (m, p-mixture, purity 81%), 1.3 parts of 80% acrylic acid aqueous solution, 0.5 parts of sodium dodecylbenzenesulfonate, and 46.7 parts of water were mixed. Stir to prepare an aqueous dispersion of the monomer mixture.

While stirring the reaction vessel, the temperature was heated to 80 ° C., and 8 parts of a 5% sodium persulfate aqueous solution as a polymerization initiator was charged. While stirring the reaction vessel, the temperature was maintained at 80 ° C., and the aqueous dispersion of the monomer mixture was charged for 2 hours continuously. Further, after the entire aqueous dispersion of the monomer was charged into the reaction container, 19.6 parts of styrene, 0.4 parts of divinylbenzene (m, p-mixture, 81% purity), and 6% ammonium hydroxide were charged at once. 20 servings. Thereafter, the temperature was raised to 85 ° C., and the mixture was further aged for 2 hours under stirring to obtain the water content of a spherical hollow seed particle B having a single pore with a particle diameter of 0.487 μm, an inner diameter of 0.312 μm, and a volume porosity of 26%. Dispersion (30.9% solids).

Into a reaction vessel with a capacity of 2 liters, 569 parts of water, 100 parts of solid content (324 parts of aqueous dispersion) of the hollow seed particle B aqueous dispersion, 20 parts of styrene, and diethylene glycol were charged. 80 parts of m-benzene (m, p-mixture, purity 81%), 4 parts of sodium dodecylbenzenesulfonate. While stirring the reaction vessel, the reaction vessel was kept at 40 ° C. for 3 hours, and then heated to 65 ° C., and 6 parts of a 5% aqueous solution of sodium persulfate as a polymerization initiator was charged. The reaction vessel was further heated and maintained at 80 ° C. with continuous stirring. Two hours later, 2 parts of a 5% aqueous solution of sodium persulfate was added to the reaction container at 80 ° C., and the stirring was continued for 1 hour. Thereafter, the temperature was raised to 85 ° C., 2 parts of a 5% aqueous solution of sodium persulfate was added after 1 hour, and the mixture was further aged for 1 hour with stirring. Thereafter, the reaction vessel was cooled to 40 ° C., and the contents were filtered using a nylon mesh with a mesh size of 50 μm, and further subjected to pressure filtration using a polypropylene cartridge filter with a filtration accuracy of 10 μm to obtain hollow particles 1 Aqueous dispersion (solid content of 20.5%). A mini spray dryer B-290 manufactured by Buchi, Japan was used and the obtained aqueous dispersion was dried by a spray drying method (temperature 110 ° C to 220 ° C) to obtain a particle size of Spherical hollow particle 1 with a single pore of 0.609 μm, an inner diameter of 0.381 μm, and a volume void ratio of 24%.

In addition, a transmission electron microscope (manufactured by Hitachi High-technologies Co., Ltd., model "H-7650") was used to measure the major axis (Rmax) and minor axis (Rmin) of any 20 hollow particles 1 ) The measurement was performed and the average value was calculated. As a result, the major axis was 0.615 μm, the minor axis was 0.604 μm, and the ratio of major axis to minor axis (Rmax / Rmin) was 1.02.

In addition, using the obtained aqueous dispersion of hollow particles 1 as a sample, a particle size distribution measuring device (manufactured by Otsuka Electronics Co., Ltd., model "ELSZ-1000ZS" based on dynamic light scattering method) was used as a sample. "), The number average particle diameter (Dn) and the standard deviation (σ) of the particle size distribution of the hollow particles 1 were obtained. As a result, the number average particle diameter (Dn) was 0.609 μm, and the standard deviation (σ) was 0.034 μm. From these values, the particle variation coefficient (CV value) was calculated by the following formula (1). As a result, the CV value was 0.056. CV value = standard deviation (σ) of particle size distribution / number average particle size (Dn) ... (1)

3.1.2. Production of hollow particles 2 An aqueous dispersion of the above-mentioned hollow seed particles B was charged with 569 parts of water and 100 parts by solid content (324 parts by aqueous dispersion) into a reaction vessel having a capacity of 2 liters. 20 parts of styrene, 80 parts of divinylbenzene (m, p-mixture, purity 81%), 4 parts of sodium dodecylbenzenesulfonate. While stirring the reaction vessel, the reaction vessel was kept at 40 ° C. for 3 hours, and then heated to 70 ° C., and 6 parts of a 5% aqueous solution of sodium persulfate as a polymerization initiator was charged. The temperature was kept at 70 ° C. and stirring was continued. Two hours after the temperature reached 70 ° C., 2 parts of a 5% aqueous solution of sodium persulfate was added, and the mixture was further aged for 1 hour with stirring. Thereafter, the reaction vessel was cooled to 40 ° C., and the contents were filtered using a nylon mesh with a mesh size of 50 μm, and further subjected to pressure filtration using a polypropylene cartridge filter with a filtration accuracy of 10 μm to obtain hollow particles 2 Aqueous dispersion (solid content of 20.5%). A small spray dryer type B-290 manufactured by Buchi, Japan was used and the obtained aqueous dispersion was dried by a spray drying method (temperature 110 ° C to 220 ° C) to obtain a particle diameter of 0.560 μm and an inner diameter. A spherical hollow particle 2 having a single void of 0.260 μm and a volume porosity of 10%.

The long diameter (Rmax) and short diameter (Rmin) of the hollow particle 2 were measured in the same manner as the hollow particle 1. As a result, the long diameter was 0.587 μm, the short diameter was 0.534 μm, and the ratio of the long diameter to the short diameter (Rmax / Rmin) was 1.10. . In addition, the number average particle diameter, standard deviation, and particle variation coefficient of the hollow particles 2 were determined in the same manner as the hollow particle 1. As a result, the number average particle diameter was 0.560 μm, the standard deviation was 0.099 μm, and the particle variation coefficient was 0.177.

3.1.3. Preparation of hollow particles 3 An aqueous dispersion of the seed particles A was charged with 143 parts of water and 10 parts by solid content (34 parts by aqueous dispersion) into a reaction vessel with a capacity of 2 liters. 1.2 parts of 80% acrylic acid aqueous solution. On the other hand, 78 parts of styrene, 1.3 parts of an 80% acrylic acid aqueous solution, 0.5 parts of sodium dodecylbenzenesulfonate, and 46.7 parts of water were mixed and stirred to prepare an aqueous dispersion of a monomer mixture.

While stirring the reaction vessel, the temperature was heated to 80 ° C., and 8 parts of a 5% sodium persulfate aqueous solution as a polymerization initiator was charged. While stirring the reaction vessel, the temperature was maintained at 80 ° C., and the aqueous dispersion of the monomer mixture was charged for 2 hours continuously. Further, after the entire aqueous dispersion of the monomer was charged into the reaction container, 20 parts of divinylbenzene (m, p-mixture, purity 81%) and 20 parts of 6% ammonium hydroxide were charged at once. Thereafter, the temperature was raised to 85 ° C., and the mixture was aged with stirring for 2 hours. Thereafter, the reaction vessel was cooled to 40 ° C, and the contents were filtered using a nylon mesh with a mesh size of 50 μm, and further filtered under pressure using a polypropylene cartridge filter with a filtration accuracy of 10 μm to obtain hollow particles 3 Aqueous dispersion (solid content of 20.5%). A small spray dryer type B-290 manufactured by Buchi, Japan was used and the obtained aqueous dispersion was dried by a spray drying method (temperature 110 ° C to 220 ° C) to obtain a particle diameter of 0.541 μm and an inner diameter. Spherical hollow particles 3 having a single void of 0.427 μm and a volume void ratio of 49%.

The long diameter (Rmax) and short diameter (Rmin) of the hollow particle 3 were measured in the same manner as the hollow particle 1. As a result, the long diameter was 0.614 μm, the short diameter was 0.469 μm, and the ratio of the long diameter to the short diameter (Rmax / Rmin) was 1.31. . In addition, the number average particle diameter, standard deviation, and particle variation coefficient of the hollow particles 3 were determined in the same manner as the hollow particle 1. As a result, the number average particle diameter was 0.541 μm, the standard deviation was 0.162 μm, and the particle variation coefficient was 0.299.

3.1.4. Preparation of dense particles 1 An aqueous dispersion of the seed particles A was charged with 947 parts of water and 1.6 parts by solid content (5.5 parts by water dispersion) into a reaction vessel having a capacity of 2 liters. With 0.5 part of sodium dodecylbenzenesulfonate, the temperature was heated to 85 ° C. while stirring, and 10 parts of a 3% potassium persulfate aqueous solution as a polymerization initiator was charged. The temperature was maintained at 85 ° C., and a monomer mixture containing 80 parts of styrene and 20 parts of divinylbenzene (m, p-mixture, purity 81%) was charged for 3 hours. Then, after 2 hours of aging, the reaction vessel was cooled to 40 ° C, and the contents were filtered using a nylon mesh with a mesh size of 50 μm, and then pressed with a polypropylene cartridge filter with a filtration accuracy of 10 μm. Filtration was performed to obtain an aqueous dispersion of solid particles 1 (solid content: 10.0%). A small spray dryer type B-290 manufactured by Buchi, Japan was used and the obtained aqueous dispersion was dried by a spray drying method (temperature 110 ° C to 220 ° C) to obtain dense particles having a particle size of 0.813 μm 1.

The long diameter (Rmax) and short diameter (Rmin) of the dense particle 1 were measured in the same manner as the hollow particle 1. As a result, the long diameter was 0.871 μm, the short diameter was 0.755 μm, and the ratio of the long diameter to the short diameter (Rmax / Rmin) was 1.15. . In addition, the number average particle diameter, standard deviation, and particle variation coefficient of the dense particles 1 were obtained in the same manner as the hollow particles 1. As a result, the number average particle diameter was 0.813 μm, the standard deviation was 0.109 μm, and the particle variation coefficient was 0.134.

3.1.5. Production of core-shell particles For bis (3,5,5-trimethylhexamidine) peroxide (trade name "Peroyl (registered trademark) 355", manufactured by Nippon Oil Corporation) , Water solubility: 0.01%) 2 parts, 0.1 parts of sodium dodecylbenzenesulfonate and 17.9 parts of water after stirring and emulsification, further homogenization with an ultrasonic homogenizer (manufactured by SMT (stock)) to obtain polymerization Aqueous dispersion of initiator. To the prepared aqueous dispersion of the polymerization initiator, 15 parts of the solid content (150 parts of the aqueous dispersion) as the core particles of the aqueous dispersion of the dense particles 1 were added and stirred for 16 hours. Thereafter, 680 parts of water, 90 parts of methyl methacrylate, 10 parts of ethylene glycol dimethacrylate, and 50 parts of 10% aqueous solution of Joncryl (registered trademark) 62 manufactured by BASF were added. Then, the temperature was maintained at 40 ° C. and stirred for 3 hours, and the temperature was further maintained at 80 ° C. and stirred for 3 hours, thereby synthesizing the polymer-coated core-shell particles on the surface of the dense particles 1. Thereafter, the reaction vessel was cooled to 40 ° C, and the contents were filtered using a nylon mesh with a mesh size of 50 μm, and further subjected to pressure filtration using a polypropylene cartridge filter with a filtration accuracy of 10 μm to obtain core-shell particles. Aqueous dispersion (solid content: 12.2%). A small spray dryer type B-290 manufactured by Buchi, Japan was used and the obtained aqueous dispersion was dried by a spray drying method (temperature 110 ° C to 220 ° C) to obtain a core-shell having a particle diameter of 1.54 μm particle.

The long diameter (Rmax) and short diameter (Rmin) of the core-shell particles were measured in the same manner as in the hollow particle 1, and the average values were calculated. As a result, the long diameter was 1.56 μm, the short diameter was 1.51 μm, and the ratio of the long diameter to the short diameter (Rmax) / Rmin) was 1.03. In addition, the number-average particle diameter, standard deviation, and particle variation coefficient of the core-shell particles were obtained in the same manner as the hollow particle 1. As a result, the number-average particle diameter was 1.540 μm, the standard deviation was 0.154 μm, and the particle variation coefficient was 0.100.

3.1.6. Preparation of special-shaped particles Into a reaction vessel having a capacity of 2 liters, 947 parts of water, 1.6 parts by solid content (5.5 parts by aqueous dispersion) of the aqueous dispersion of the seed particles A, 80 parts of styrene, 15 parts of divinylbenzene (m, p-mixture, purity 81%), 5 parts of 2-hydroxyethyl methacrylate, 0.5 parts of sodium dodecylbenzenesulfonate, while stirring The temperature was heated to 85 ° C, and 10 parts of a 3% potassium persulfate aqueous solution as a polymerization initiator was charged. The temperature was maintained at 85 ° C. for 6 hours, and an aqueous dispersion (solid content: 10.0%) of the first polymer particles having a particle diameter of 0.809 μm was obtained.

2 parts of bis (3,5,5-trimethylhexamidine) peroxide (trade name "Peroyl (registered trademark) 355", manufactured by Nippon Oil & Gas Co., Ltd., water solubility: 0.01%) After stirring and emulsifying 0.1 parts of sodium dodecylbenzenesulfonate and 17.9 parts of water, the particles were further micronized using an ultrasonic homogenizer (manufactured by SMT) to obtain an aqueous dispersion of a polymerization initiator. To the produced aqueous dispersion of the polymerization initiator, 15 parts by weight of the solid content (150 parts by weight of the aqueous dispersion) of the first polymer particle aqueous dispersion was added and stirred for 16 hours. Thereafter, 680 parts of water, 90 parts of methyl methacrylate, 10 parts of ethylene glycol dimethacrylate, and 50 parts of 10% aqueous solution of Joncryl (registered trademark) 62 manufactured by BASF were added. Then, the temperature was maintained at 40 ° C. and stirred for 3 hours, and then the temperature was maintained at 80 ° C. and stirred for 3 hours, thereby synthesizing irregular particles. Thereafter, the reaction vessel was cooled to 40 ° C., and the contents were filtered using a nylon mesh with a mesh size of 50 μm, and further subjected to pressure filtration using a polypropylene cartridge filter with a filtration accuracy of 10 μm to obtain the water of the shaped particles. Dispersion (solid content: 12.2%). A small spray dryer type B-290 manufactured by Buchi, Japan was used and the obtained aqueous dispersion was dried by a spray drying method (temperature 110 ° C to 220 ° C) to obtain shaped particles having a particle diameter of 1.67 μm .

The long diameter (Rmax) and short diameter (Rmin) of the shaped particles were measured in the same manner as in the hollow particle 1, and the average values were calculated. As a result, the long diameter was 1.81 μm, the short diameter was 1.53 μm, and the ratio of the long diameter to the short diameter (Rmax / Rmin) was 1.18. In addition, the number-average particle diameter, standard deviation, and particle variation coefficient of the irregular particles were calculated in the same manner as the hollow particles 1. As a result, the number-average particle diameter was 1.670 μm, the standard deviation was 0.147 μm, and the particle variation coefficient was 0.088.

3.1.7. Production of calcium carbonate particles A The calcium carbonate purchased from Wako Pure Chemical Industries, Ltd. was crushed by an agate mortar, and further classified by a water sieve, and then a small spray manufactured by Buchi, Japan was used. The dryer B-290 was dried by a spray-drying method (temperature: 110 ° C to 220 ° C), thereby producing light-diffusing particles having a particle length-to-length ratio described in Table 1. An aqueous dispersion obtained by dispersing the obtained calcium carbonate particles A in water using a ultrasonic disperser was used as a sample, and the number average particle diameter, standard deviation, and Particle variation coefficient. As a result, the number average particle diameter was 2.23 μm, the standard deviation was 0.443 μm, and the particle variation coefficient was 0.199. In addition, the long diameter (Rmax) and short diameter (Rmin) of the calcium carbonate particle A were measured in the same manner as in the hollow particle 1, and the average values were calculated. As a result, the long diameter was 2.32 μm and the short diameter was 2.13 μm. The ratio (Rmax / Rmin) is 1.09.

3.1.8. Production of barium sulfate particles A The barium sulfate purchased from Wako Pure Chemical Industries Co., Ltd. was crushed by an agate mortar, and further classified by a water sieve, and then a small spray manufactured by Buchi, Japan was used. The dryer B-290 was dried by a spray-drying method (temperature: 110 ° C to 220 ° C), thereby producing light-diffusing particles having a particle length-to-length ratio described in Table 1. An aqueous dispersion obtained by dispersing the obtained barium sulfate particles A in water using an ultrasonic disperser was used as a sample, and the number average particle diameter, standard deviation, and Particle variation coefficient. As a result, the number average particle diameter was 1.970 μm, the standard deviation was 0.355 μm, and the particle variation coefficient was 0.180. In addition, the long diameter (Rmax) and short diameter (Rmin) of the barium sulfate particle A were measured in the same manner as the hollow particles 1. The average values were calculated. As a result, the long diameter was 2.14 μm, the short diameter was 1.80 μm, The ratio (Rmax / Rmin) is 1.19.

3.1.9. Production of barium sulfate particles B The barium sulfate purchased from Wako Pure Chemical Industries Co., Ltd. was pulverized in a porcelain mortar, and then classified with a water sieve. A small spray manufactured by Buchi, Japan was used. The dryer B-290 was dried by a spray-drying method (temperature: 110 ° C to 220 ° C), thereby producing light-diffusing particles having a particle length-to-length ratio described in Table 1. An aqueous dispersion obtained by dispersing the obtained barium sulfate particles B in water using an ultrasonic disperser was used as a sample, and the number average particle diameter, standard deviation, and Particle variation coefficient. As a result, the number average particle diameter was 3.97 μm, the standard deviation was 0.881 μm, and the particle variation coefficient was 0.222. In addition, the long diameter (Rmax) and short diameter (Rmin) of the barium sulfate particle B were measured in the same manner as the hollow particles 1. The average values were calculated. As a result, the long diameter was 4.99 μm, the short diameter was 2.95 μm, The ratio (Rmax / Rmin) is 1.69.

3.1.10. Production of titanium dioxide particles A The titanium dioxide purchased from Wako Pure Chemical Industries, Ltd. was crushed by an agate mortar, and then classified by a water sieve. A small spray dryer manufactured by Buchi, Japan was used. Type B-290 was dried by a spray-drying method (temperature: 110 ° C to 220 ° C), thereby producing light-diffusing particles having a particle length / length ratio described in Table 1. An aqueous dispersion obtained by dispersing the obtained titanium dioxide particles A in water using an ultrasonic disperser was used as a sample, and the number average particle diameter, standard deviation, and particle variation of the titanium dioxide particles A were determined in the same manner as the hollow particles 1. As a result, the number average particle diameter was 2.67 μm, the standard deviation was 0.400 μm, and the particle variation coefficient was 0.150. In addition, the long diameter (Rmax) and short diameter (Rmin) of the titanium dioxide particles A were measured in the same manner as the hollow particles 1. The average values were calculated. As a result, the long diameter was 2.73 μm, the short diameter was 2.60 μm, and the ratio of the long diameter to the short diameter was calculated. (Rmax / Rmin) is 1.05.

3.2. Example 1 20 parts by mass of the hollow particles prepared as described above, 33.1 parts by mass of bisphenol A epoxy diacrylate (manufactured by Arkema Co., Ltd., trade name "CN104"), 2- 40.1 parts by mass of hydroxy-3-phenoxypropyl acrylate (trade name "New Frontier PGA", manufactured by Daiichi Kogyo Co., Ltd.), bis (2- (meth) acrylic acid) 0.4 parts by mass of 1-hydroxycyclohexylphenyl ketone (trade name "Yanjiagu (" Kayamer) PM-2 ", manufactured by Nippon Kayaku Co., Ltd.) Irgacure) 184 ", 6.3 parts by mass of BASF Japan (stock), 0.08 parts by mass of hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), 2-methyl-4-isothiazole Porphyrin-3-one (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed in an amount of 0.04 parts by mass, and was further prepared so that the moisture in the constituents became 0.4 parts by mass. Furthermore, they were kneaded using a planetary agitator (manufactured by Kurabo Industries Co., Ltd., model number "KK-50S") to prepare a composition for a light guide plate containing hollow particles 1 as light diffusion particles (A).

Next, a glass light guide substrate (a glass substrate manufactured by Nippon Electric Glass Co., Ltd., product name "OA-10G", and surface roughness Ra = 0.5 nm manufactured by the overflow method) was placed on a work table. The obtained composition for a light guide plate was screen-printed into a dot shape from above, and thereafter was cured by ultraviolet irradiation to produce a light guide plate having a light diffusion portion formed thereon.

In addition, the coating conditions, the ultraviolet irradiation conditions, and the evaluation method of the composition for light-guide plates are as follows.

<Coating conditions> Screen printing was performed with dots under the following conditions. The dot diameter is set to 300 μm, the dot film thickness is set to 15 μm, and the dot pattern is set to a pitch gradient design with a pitch of 500 μm to 2000 μm. · Dimensions of the light guide substrate: length (length in the light guide direction) is 718 mm, width is 413 mm, and thickness is 2 mm · coating surface: exit surface (the surface of the light guide substrate) · Mesh: 420 mesh / inch · Ink scraping angle: 50 ° · Ink scraping speed: 65 mm / s · Ink scraping pressure: 0.198 kgf / cm ² · Interval: 1.1 mm

<Ultraviolet irradiation conditions> · Lamp: Ultra-high pressure mercury lamp (irradiation wavelength is 280 nm to 500 nm) · Irradiance: 550 mJ / cm ² (365 nm)

<Evaluation method> (1) Evaluation of hardenability As described above, after curing the composition for a light guide plate by ultraviolet irradiation, the formed light diffusion portion was subjected to contact diagnosis, and it was judged that the adhesiveness was recognized as poor hardening, and It is expressed as "×" in the table, and when the tackiness is not recognized, it is judged that the hardenability is good and it is expressed as "○" in the table.

(2) Evaluation of uneven brightness and uneven chromaticity of the light guide plate A light source in which linear white LEDs are arranged at both ends of the produced light guide plate, and a white diffuse reflection film is laminated on the back side of the light guide plate. A light-diffusion film was laminated | stacked on the coating surface which becomes a front side, and the edge-light type back light source was produced. Observe by visual observation at a position 2 m away from the edge-lit back-side light source from the front. The entire surface is uniformly bright, and no uneven brightness is recognized. Therefore, it can be judged as very good. It is stated in the table as "◎ ", The case where a slight uneven brightness is confirmed but it can be judged that it can be used for applications that do not strictly require homogeneous brightness is expressed as" ○ "in the table, and the case where it is clearly confirmed that the uneven brightness is difficult to use is judged to be defective and It is expressed as "×" in the table.

Furthermore, when visually observed at a position 2 m away from the edge-lit back-side light source from the front, the case where the chromaticity unevenness cannot be recognized, the light emission is white, and it can be judged to be very good is expressed in the table as "◎" In the table, the case where the chromaticity unevenness is slightly recognized but can be judged to be used for white light emission that is not strictly required is expressed as "○" in the table, and the chromaticity unevenness in the plane is large and difficult to use. It is bad and is expressed as "×" in the table.

(3) Storage stability The prepared light guide plate composition is stored at room temperature and in a light-shielded environment, and the light guide plate is produced by the method every month, and the brightness unevenness and chromaticity unevenness are evaluated. Evaluation was performed to evaluate the storage stability of the composition for a light guide plate. The brightness unevenness and chromaticity unevenness of the light guide plate are equal to those in the case of using the composition for a light guide plate immediately after the preparation, which is expressed as "◎" in the table. The change will be slightly observed without affecting the judgment. A case where it can be used as a light guide plate is expressed as “○” in the table, and a case where the judgment as to whether it can be used is different is expressed as “×” in the table.

<Measurement of Reflectivity of Hardened Film> A glass light guide substrate (a glass substrate manufactured by Nippon Electric Glass Co., Ltd., trade name "OA-10G", surface roughness Ra = 0.5 nm manufactured by the overflow method) was placed on It was placed on a workbench, and the composition for a light guide plate was applied from above under the coating conditions, and then it was hardened by ultraviolet irradiation under the ultraviolet irradiation conditions to produce a composition for a light guide plate having a thickness of 10 μm. Hardened film. About the hardened film produced in the above-mentioned manner, the maximum reflectance at a wavelength of 300 nm to 380 nm was obtained from a reflection spectrum measured using a spectrophotometer (manufactured by Japan Spectroscopy Corporation, model "V-670"). (% Rmax) and minimum reflectance (% Rmin), and maximum reflectance (% Rmax) and minimum reflectance (% Rmin) at a wavelength of 400 nm to 800 nm. The results are shown in Table 1 together.

3.3. Example 2 to Example 3 A light guide plate combination was produced in the same manner as in Example 1 except that the type of the light diffusing particles (A) was set to the particles described in Table 1 and the amounts of each component were changed. And evaluated.

3.4. Example 4 10 parts by mass of the core-shell particles prepared as described above, 36.6 parts by mass of bisphenol A epoxy diacrylate (manufactured by Arkema Co., Ltd., trade name "CN104"), 2- 44.4 parts by mass of hydroxy-3-phenoxypropyl acrylate (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd. under the trade name "New Frontier PGA"), bis (2- (meth) acrylic acid) 0.44 parts by mass of 1-hydroxycyclohexylphenyl ketone (BASF JAPAN) (manufactured by Nippon Kayaku Co., Ltd., trade name "KAYAMER PM-2") Stock), 7.0 parts by mass of "Irgacure 184"), 0.05 parts by mass of hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), 2-methyl-4-isothiazole Porphyrin-3-one (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed in an amount of 0.1 parts by mass, and was further prepared so that the moisture in the constituents became 1.5 parts by mass. Furthermore, a planetary stirring device (model "KK-50S" manufactured by Kurashiki Textile Co., Ltd.) was used for kneading to prepare a composition for a light guide plate containing core-shell particles as light diffusion particles (A), and Examples 1 Evaluation was performed in the same manner.

3.5. Example 5 30 mass parts of the shaped particles produced as described above, 28.8 parts by mass of bisphenol A epoxy diacrylate (manufactured by Arkema Co., Ltd., trade name “CN104”), 2-hydroxyl -3-phenoxypropyl acrylate (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., trade name "New Frontier PGA") 34.8 parts by mass, bis (2- (meth) acrylic acid) Methyl ethyl) phosphate (manufactured by Nippon Kayaku Co., Ltd., trade name "KAYAMER PM-2") 0.35 parts by mass, 1-hydroxycyclohexylphenyl ketone (BASF JAPAN, Japan ) Manufactured, trade name "Irgacure 184") 5.45 parts by mass, hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 parts by mass, 2-methyl-4-isothiazoline -3-one (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed in an amount of 0.1 parts by mass, and was further prepared so that the moisture in the constituents became 0.4 parts by mass. Furthermore, a planetary stirring device (model "KK-50S" manufactured by Kurashiki Textile Co., Ltd.) was used for kneading to prepare a composition for a light guide plate containing irregular particles as light diffusion particles (A), and Example 1 Evaluation was performed in the same manner.

3.6. Example 6 9 parts by mass of the calcium carbonate particles A prepared as described above, bisphenol A epoxy diacrylate (manufactured by Arkema Co., Ltd., trade name “CN104”), 37.6 parts by mass, 2 -45.6 parts by mass of bis (2- (meth) propylene) -hydroxy-3-phenoxypropyl acrylate (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., trade name "New Frontier PGA") 0.45 parts by mass of 1-hydroxycyclohexylphenyl ketone (BASF JAPAN), manufactured by Nippon Kayaku Co., Ltd., under the trade name "KAYAMER PM-2". (Stock) manufacturing, trade name "Irgacure 184") 7.17 parts by mass, hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 0.06 parts by mass, 2-methyl-4-iso Thiazolin-3-one (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed in an amount of 0.02 parts by mass, and was further prepared so that the moisture in the constituents became 0.02 parts by mass. Furthermore, they were kneaded using a planetary agitator (manufactured by Kurashiki Textile Co., Ltd., model "KK-50S") to prepare a composition for a light guide plate containing calcium carbonate particles A as light diffusion particles (A). Example 1 was evaluated in the same manner.

3.7. Example 7 97.6 parts by mass of the barium sulfate particles A produced as described above, bisphenol A epoxy diacrylate (manufactured by Arkema Co., Ltd., trade name “CN104”), 37.6 parts by mass, 2 -45.6 parts by mass of bis (2- (meth) propylene) -hydroxy-3-phenoxypropyl acrylate (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., trade name "New Frontier PGA") 0.45 parts by mass of 1-hydroxycyclohexylphenyl ketone (BASF JAPAN), manufactured by Nippon Kayaku Co., Ltd., under the trade name "KAYAMER PM-2". (Stock) manufacturing, trade name "Irgacure 184") 7.17 parts by mass, hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 0.05 parts by mass, 2-methyl-4-iso The thiazolin-3-one (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed in an amount of 0.03 parts by mass, and was further prepared so that the moisture in the constituents became 0.03 parts by mass. Furthermore, they were kneaded using a planetary agitator (manufactured by Kurashiki Textile Co., Ltd., model number "KK-50S") to prepare a composition for a light guide plate containing barium sulfate particles A as light diffusion particles (A), and implemented Example 1 was evaluated in the same manner.

3.8. Example 8 9 parts by mass of the prepared titanium dioxide particles A, 37.6 parts by mass of bisphenol A epoxy diacrylate (manufactured by Arkema Co., Ltd., trade name "CN104"), 2- 45.6 parts by mass of hydroxy-3-phenoxypropyl acrylate (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., "New Frontier PGA"), bis (2- (meth) acrylic acid) 0.45 parts by mass of 1-hydroxycyclohexylphenyl ketone (BASF JAPAN) (manufactured by Nippon Kayaku Co., Ltd., trade name "KAYAMER PM-2") Manufactured under the trade name "Irgacure 184") 7.17 parts by mass, 0.3 parts by mass of hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), 2-methyl-4-isothiazole Porphyrin-3-one (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed in an amount of 0.03 parts by mass, and was further prepared so that the moisture in the constituents became 0.04 parts by mass. Furthermore, a planetary stirring device (model "KK-50S" manufactured by Kurashiki Textile Co., Ltd.) was used for kneading to prepare a composition for a light guide plate containing titanium dioxide particles A as light diffusion particles (A), and Examples 1 Evaluation was performed in the same manner.

3.9. Comparative Example 1 to Comparative Example 2 A light guide plate combination was produced in the same manner as in Example 1 except that the light diffusing particles (A) were changed to the particles and contents described in Table 1, and the amount of each component was changed. And evaluated.

3.10. Evaluation results The following Table 1 shows the composition, physical properties, and evaluation results of the composition for a light guide plate used in each of Examples and Comparative Examples.

[Table 1]

In addition, as the materials described in Table 1, the products or compounds described below were used. Dispersion medium (B): · B1: Bisphenol A epoxy diacrylate, manufactured by Arkema (stock), trade name "CN104" · B2: 2-hydroxy-3-phenoxypropyl acrylic acid Ester, Daiichi Kogyo Pharmaceutical Co., Ltd., trade name "New Frontier PGA" radical scavenger (C): hydroquinone monomethyl ether, Wako Pure Chemical Industries, Ltd. Polymerization initiator: 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF JAPAN (Japan), trade name "Irgacure 184" Phosphate ester: bis (2- (meth) acryl fluorenyloxy) Ethyl) phosphate, manufactured by Nippon Kayaku Co., Ltd., trade name "KAYAMER PM-2" Isothiazoline compounds: 2-methyl-4-isothiazolin-3-one, Wako Pure Chemicals Pharmaceutical industry (stock) manufacturing water: ion exchange water

It is understood that the compositions for light guide plates of Examples 1 to 8 have good curability and excellent storage stability. In addition, it was found that the light guide plate produced by using the composition for a light guide plate of Examples 1 to 8 can effectively suppress uneven brightness or uneven chromaticity, and therefore, the surface light emission of the light guide plate is excellent in homogeneity and exhibits good performance. Luminous characteristics.

The present invention is not limited to the embodiments described above, and various modifications are possible. The present invention includes a configuration substantially the same as the configuration described in the embodiment (for example, a configuration having the same function, method, and result, or a configuration having the same object and effect). In addition, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced with another configuration. Furthermore, the present invention includes a configuration that exhibits the same functions and effects as the configuration described in the above-mentioned embodiment or a configuration that can achieve the same purpose. Furthermore, the present invention also includes a configuration in which a known technique is added to the configuration described in the embodiment.

1‧‧‧light guide
3‧‧‧ light source
11‧‧‧light guide substrate
12‧‧‧Light Diffusion Department
20‧‧‧ surface light source device
30‧‧‧Transmissive image display section
40a, 40b, 40c ‧‧‧ light diffusion particles
50a, 50b, 50c, 50d, 50e, 50f
52a, 52b, 52c, 52d, 52e, 52f‧‧‧ 1st light diffusion particle
54a, 54b, 54c, 54d, 54e, 54f‧‧‧ 2nd light diffusion particle
100‧‧‧Transmissive image display device (liquid crystal display device)
a‧‧‧long axis
b‧‧‧ short axis
c, e‧‧‧ longest distance
d, f‧‧‧ shortest diameter
Rmax‧‧‧length
Rmin‧‧‧Short Path
S1, S2 ‧‧‧ (light guide substrate) exit surface
S3 ₁ , S3 ₂ , S3 ₃ , S3 ₄ ‧‧‧ (of the light guide substrate)

FIG. 1 is a cross-sectional conceptual view showing an example of an edge-emission type surface light-emitting device. FIG. 2 is a plan view of a side of a light guide plate where a light diffusion portion is formed. FIG. FIG. 3 is an explanatory diagram schematically showing the concepts of the major and minor diameters of the light diffusion particles (A). FIG. 4 is an explanatory diagram schematically showing the concepts of the major and minor diameters of the light diffusion particles (A). FIG. 5 is an explanatory diagram schematically showing the concepts of the major and minor diameters of the light diffusion particles (A). FIG. 6 is an explanatory diagram schematically showing the concept of an irregular particle. FIG. 7 is an explanatory diagram schematically showing the concept of a shaped particle. FIG. 8 is an explanatory diagram schematically showing the concept of a shaped particle. FIG. 9 is an explanatory diagram schematically showing the concept of a shaped particle. FIG. 10 is an explanatory diagram schematically showing the concept of a shaped particle. FIG. 11 is an explanatory diagram schematically showing the concept of a shaped particle.

1‧‧‧light guide

3‧‧‧ light source

11‧‧‧light guide substrate

12‧‧‧Light Diffusion Department

20‧‧‧ surface light source device

30‧‧‧Transmissive image display section

100‧‧‧Transmissive image display device (liquid crystal display device)

S1, S2‧‧‧‧ (outside of light guide substrate)

S3 ₁ , S3 ₂ ‧‧‧ (of the light guide substrate)

Claims (7)

A composition for a light guide plate containing light diffusing particles (A) and a dispersion medium (B), wherein a cured film having a thickness of 10 μm and a wavelength of 300 μm to 380 nm is prepared by using the composition for a light guide plate. The reflectivity is 0% to 50%, and the reflectance at a wavelength of 400 nm to 800 nm is 30% to 99%. The composition for a light guide plate according to item 1 of the scope of patent application, wherein the standard deviation of the particle size distribution of the light diffusion particles (A) divided by the number average particle size is 0.01 to 0.2, wherein The value is the coefficient of particle variation. The composition for a light guide plate according to item 1 or item 2 of the scope of patent application, wherein the ratio Rmax / Rmin of the major axis Rmax to the minor axis Rmin of the light diffusion particle (A) is in a range of 1.01 to 1.2. The composition for a light guide plate according to claim 1 or claim 2, comprising a photopolymerizable component as the dispersion medium (B). The composition for a light guide plate according to item 1 or 2 of the scope of patent application, further comprising a radical scavenger (C). The composition for a light guide plate according to claim 1 or claim 2, further comprising an isothiazoline compound. A light guide plate is manufactured by using the composition for a light guide plate according to any one of claims 1 to 6 of the scope of patent application.