JP2010134097A - Light-diffusing structure - Google Patents
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
- G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
- G02B5/0236—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element
- G02B5/0242—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element by means of dispersed particles
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133504—Diffusing, scattering, diffracting elements
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
Abstract
Description
本発明は耐酸性および耐有機溶剤性に優れた光拡散層を備えた光拡散構造体に関する。さらに詳しくは、液晶ディスプレイ装置のバックライトユニット、照明器具用、プロジェクタのスクリーン等に好適に用いることのできる光拡散構造体に関する。 The present invention relates to a light diffusion structure provided with a light diffusion layer excellent in acid resistance and organic solvent resistance. More specifically, the present invention relates to a light diffusion structure that can be suitably used for a backlight unit of a liquid crystal display device, a lighting fixture, a projector screen, and the like.
光拡散構造体は、電球やＬＥＤ等の点光源または蛍光管等の線光源の光を拡散させて、均一で正面輝度の高い面照明を得る目的で用いられる。この光拡散構造体は、例えば携帯電話、デジタルカメラ、液晶テレビ等の液晶ディスプレイのバックライトユニット用の光拡散フィルム、液晶プロジェクタ用のスクリーン、家庭用照明器具および施設照明の光拡散板、道路標識、看板、販促用ＰＯＰや各種イルミネーション用の光拡散フィルムなどとして広く使用されている。
光拡散構造体は、透明な基材の表面に、光拡散材としてシリカ、アクリルまたはポリスチレン等の真球状透明粒子を分散させた、透明な合成樹脂（バインダ）層から構成される光拡散層が形成された構造からなるものが知られている。
光拡散構造体に対しては、その光拡散作用にもとづく隠蔽力により導光板のドットパターン、線状パターン、照明光源の輪郭、輝点を消して均一な面発光を与えるという機能が要求されている。
The light diffusing structure is used for the purpose of diffusing the light of a point light source such as a light bulb or LED or a line light source such as a fluorescent tube to obtain uniform surface illumination with high front luminance. The light diffusing structure includes, for example, a light diffusing film for a backlight unit of a liquid crystal display such as a mobile phone, a digital camera, and a liquid crystal television, a screen for a liquid crystal projector, a light diffusing plate for household lighting equipment and facility lighting, and a road sign. It is widely used as a signboard, a POP for sales promotion, and a light diffusion film for various illuminations.
The light diffusion structure has a light diffusion layer composed of a transparent synthetic resin (binder) layer in which spherical transparent particles such as silica, acrylic or polystyrene are dispersed as a light diffusion material on the surface of a transparent substrate. What consists of the formed structure is known.
The light diffusing structure is required to have a function of providing uniform surface emission by erasing the dot pattern of the light guide plate, the linear pattern, the outline of the illumination light source, and the bright spot by the hiding power based on the light diffusing action. Yes.
従って光拡散構造体には、ＪＩＳ Ｋ ７１０５に基づいて測定されるヘーズが大きいことが要求される。さらに、光拡散構造体には、光源からの発散光を収束させ高輝度を維持する機能も要求される。この機能は通常変角光度計等によって測定され、光拡散構造体の裏面側に光源を配置し、表面側において受光器を０〜１８０°の範囲で走査させ、角度に対して透過光量をプロットする。透過光が狭い方向に集中しているかどうかで光拡散構造体の集光能力を評価する。
しかし、従来は光拡散材として真球状シリコーン粒子を用いていたために、全光線透過率は高いがヘーズが小さく光拡散性が確保できなかった。また、真球状粒子は光の再帰反射性が強いために集光能力が不十分であった。また、真球状粒子を光拡散材として用いると特定方向に光を強く散乱または反射することがあり、これがぎらつき感や輝度不均一性等の不具合となって現れることがあった。さらに、真球状シリコーンは非常に高価であった。
Accordingly, the light diffusion structure is required to have a large haze measured based on JIS K 7105. Furthermore, the light diffusing structure is also required to have a function of converging diverging light from the light source and maintaining high luminance. This function is usually measured with a goniophotometer, etc., a light source is arranged on the back side of the light diffusion structure, the light receiver is scanned in the range of 0 to 180 ° on the front side, and the amount of transmitted light is plotted against the angle. To do. The light collecting ability of the light diffusion structure is evaluated based on whether or not the transmitted light is concentrated in a narrow direction.
However, since spherical silicone particles are conventionally used as the light diffusing material, the total light transmittance is high, but the haze is small and the light diffusibility cannot be ensured. Further, since spherical particles have a strong retroreflectivity of light, the light collecting ability is insufficient. In addition, when spherical particles are used as a light diffusing material, light may be strongly scattered or reflected in a specific direction, which may appear as inconveniences such as glare and uneven brightness. Furthermore, true spherical silicone was very expensive.
一般に光拡散構造体は光源の前面に配置されるため、樹脂微粒子を用いると、光拡散層表面が帯電しやすく、その結果、異物を吸着しやすい。そして付着異物を除去する工程で有機溶剤を用いると樹脂微粒子にクラックが入って輝度が低下し、生産効率を落とす要因となっていた。
また、光拡散構造体はロール状で流通することも多く、異物が付着しているとそれが原因で光拡散層表面に傷がつきやすい欠点があった。
さらに、シリカ微粒子は高価であるし、安価な樹脂製粒子を用いるとフィルム加工工程、トムソン型による構造体の打ち抜きの際やバックライトユニットの組立て工程において、光拡散面が傷つき、また樹脂粒子が脱落してしまうという問題が起きやすかった。
特許文献１の段落００４８には、光拡散材として板状、楕円体状、椀型、多角形状、円盤型、星型、表面しわ状などの異形粒子を用いたほうが、球状粒子よりも強い光拡散性を有しており、少量の添加で光拡散性に優れると共に高い全光線透過率および輝度が得られることが記載されている。
In addition, the light diffusing structure often circulates in a roll shape, and there is a defect that the surface of the light diffusing layer is easily damaged when a foreign substance is attached.
Furthermore, the silica fine particles are expensive. If inexpensive resin particles are used, the light diffusion surface is damaged in the film processing process, when the structure is punched out by the Thomson type, or in the assembly process of the backlight unit. The problem of falling out was easy to occur.
In paragraph 0048 of Patent Document 1, it is stronger light than spherical particles when using irregularly shaped particles such as plates, ellipsoids, bowls, polygons, disks, stars, and wrinkles as a light diffusing material. It describes that it has diffusibility, and is excellent in light diffusibility when added in a small amount, and high total light transmittance and brightness can be obtained.
しかし、本発明者らの知見によれば、光拡散材として板状や円盤型などの異形粒子を用いても、その粒子径のばらつきが大きい場合には、特許文献１に記載されたような光拡散効果および高い全光線透過率は得られない。 However, according to the knowledge of the present inventors, even when irregularly shaped particles such as a plate shape or a disk shape are used as the light diffusing material, when the variation in the particle diameter is large, as described in Patent Document 1 The light diffusion effect and high total light transmittance cannot be obtained.
本発明の目的は、隠蔽力が大きく、光源と組み合わせて用いると高輝度の拡散光が得られ、耐溶剤の高い光拡散構造体を提供することにある。 An object of the present invention is to provide a light diffusing structure having a high hiding power and providing diffused light with high luminance when used in combination with a light source and having high solvent resistance.
本発明者は、粒子径分布のシャープな、特定の形状の無機粒子を光拡散材として用いることにより、全光線透過率、ヘーズに優れ、隠蔽力が大きく、かつ正面輝度の高い、耐有機溶媒性の高い光拡散構造体が得られることを見出した。 The present inventor uses an inorganic particle having a specific particle shape with a sharp particle size distribution as a light diffusing material, thereby improving the total light transmittance, haze, large hiding power, and high front luminance, and is an organic solvent resistant solvent. It has been found that a highly diffusive light diffusing structure can be obtained.
即ち本発明は、
１．基材およびその上に積層された光拡散層を有する光拡散構造体であって、光拡散層は、樹脂および無機粒子を含有し、
無機粒子の形状は、碁石状、円柱板状もしくは六角柱板状であり、その粒子径分布シャープ度（Ｄ７５／Ｄ２５）は１．０≦Ｄ７５／Ｄ２５≦１．４を満足することを特徴とする光拡散構造体、
２．光拡散層内における無機粒子の平均傾き度〈θｔ〉が、０°≦〈θｔ〉≦１５°を満足する前項１に記載の光拡散構造体、
３．無機粒子が、多孔質または中空状である前項１または２に記載の光拡散構造体。
４．無機粒子が、下記式（１）で表わされるアルミニウム塩水酸化物粒子である前項１〜３のいずれか一項に記載の光拡散構造体、
That is, the present invention
1. A light diffusion structure having a base material and a light diffusion layer laminated thereon, the light diffusion layer containing a resin and inorganic particles,
The shape of the inorganic particles is a meteorite shape, a cylindrical plate shape or a hexagonal columnar plate shape, and the particle size distribution sharpness (D 75 / D 25 ) satisfies 1.0 ≦ D 75 / D 25 ≦ 1.4. A light diffusing structure characterized by
2. 2. The light diffusion structure according to item 1 above, wherein the average inclination degree <θ t > of the inorganic particles in the light diffusion layer satisfies 0 ° ≦ <θ t > ≦ 15 °,
3. 3. The light diffusing structure according to item 1 or 2, wherein the inorganic particles are porous or hollow.
4). The light diffusion structure according to any one of items 1 to 3, wherein the inorganic particles are aluminum salt hydroxide particles represented by the following formula (1):
（ただし、式中ＭはＮａ＋、Ｋ＋、ＮＨ４＋、Ｈ３Ｏ＋およびＣａ２＋からなる群より選ばれる少なくとも１種の陽イオン、Ｍ’はＺｎ２＋、Ｃｕ２＋、Ｎｉ２＋、Ｓｎ４＋、Ｚｒ４＋およびＴｉ４＋からなる群から選ばれる少なくとも１種の金属陽イオン、Ａは少なくとも１種の有機酸アニオン、Ｂは少なくとも１種の無機酸アニオンを表わし、式中ａ、ｂ、ｍ、ｎ、ｘ、ｙおよびｚは、０．７≦ａ≦１．３５、２．７≦ｂ≦３．３、０≦ｍ≦５、４≦ｎ≦７、０≦ｘ≦０．６、１．７≦ｙ≦２．４、０≦ｚ≦０．５である。）
５．樹脂が、アクリル樹脂である前項１〜４のいずれか一項に記載の光拡散構造体、
６．基材のＪＩＳ Ｋ ７１３６にもとづく全光線透過率が８０〜１００％、かつヘーズが０〜５％である前項１〜５のいずれか一項に記載の光拡散構造体、
である。
(Wherein, M is at least one cation selected from the group consisting of Na + , K + , NH 4+ , H 3 O + and Ca 2+ , and M ′ is Zn 2+ , Cu 2+ , Ni 2+ , Sn 4+. At least one metal cation selected from the group consisting of Zr 4+ and Ti 4+ , A represents at least one organic acid anion, B represents at least one inorganic acid anion, and a, b, m, n, x, y and z are 0.7 ≦ a ≦ 1.35, 2.7 ≦ b ≦ 3.3, 0 ≦ m ≦ 5, 4 ≦ n ≦ 7, 0 ≦ x ≦ 0.6, 0.7 ≦ y ≦ 2.4 and 0 ≦ z ≦ 0.5.)
5). The light diffusing structure according to any one of items 1 to 4, wherein the resin is an acrylic resin,
6). The light diffusing structure according to any one of the preceding items 1 to 5, wherein the total light transmittance based on JIS K 7136 of the substrate is 80 to 100% and the haze is 0 to 5%,
It is.
本発明の光拡散構造体は、優れた全光線透過率およびヘーズを有する。また本発明の光拡散構造体は、拡散透過光を正面に集めることができる。また、本発明の光拡散構造体は、耐溶剤性に優れ、有機溶剤によっても無機粒子にクラックが入らず輝度低下が発生しないので、生産性に優れている。本発明の光拡散構造体は、隠蔽性に優れる。本発明の光拡散構造体は、フィルム加工、トムソン型によるフィルムの打ち抜き、バックライトユニットの組立の各製造工程においても、無機粒子が脱落しにくい。
また、光拡散構造体は、帯電し難いので異物が付着しにくい上、付着異物を除去する工程で用いる有機溶剤によっても無機粒子にクラックが入らず輝度低下が発生しないので、生産性に優れている。
さらに、本発明の光拡散構造体は高価なシリカ微粒子を使用しないので経済性にも優れている。
本発明の光拡散構造体は、平行光を拡散させる用途、発散光を収束させる用途、光源や発光パターンを隠蔽する用途に用いることができる。具体的には輝度均斉度および正面輝度が高い照明を得るのに適している。
The light diffusing structure of the present invention has excellent total light transmittance and haze. Moreover, the light diffusing structure of the present invention can collect diffuse transmitted light in the front. In addition, the light diffusion structure of the present invention is excellent in solvent resistance, and is excellent in productivity since the inorganic particles are not cracked and the luminance is not lowered even by the organic solvent. The light diffusion structure of the present invention is excellent in concealment. In the light diffusing structure of the present invention, inorganic particles are unlikely to fall off in each manufacturing process of film processing, film punching by a Thomson type, and assembly of a backlight unit.
In addition, since the light diffusion structure is difficult to be charged, foreign matter is difficult to adhere to, and the organic solvent used in the process of removing the attached foreign matter does not crack the inorganic particles and does not cause a decrease in luminance. Yes.
Furthermore, since the light diffusion structure of the present invention does not use expensive silica fine particles, it is excellent in economic efficiency.
The light diffusing structure of the present invention can be used for the purpose of diffusing parallel light, the purpose of converging diverging light, and the purpose of concealing a light source or a light emission pattern. Specifically, it is suitable for obtaining illumination with high luminance uniformity and front luminance.
（無機粒子）
本発明に用いる無機粒子は、その形状が碁石状、円柱板状もしくは六角柱板状であることを特徴とする。
粒子の形状を特定する尺度の一つに、粉体工業分野において従来から用いられてきたＷａｄｅｌｌの円形度および球形度がある。Ｗａｄｅｌｌの球形度ｓは、下記式で定義される。ｓが１に近い程真球に近い。
ｓ＝（粒子と等体積の球の表面積）／（粒子の表面積）
また、Ｗａｄｅｌｌの円形度ｃは、下記式で定義される。ｃが１に近い程、真円に近い。
ｃ＝（粒子の投影面積と等面積円の周長）／（粒子の投影面の周長）
(Inorganic particles)
The inorganic particles used in the present invention are characterized in that the shape is a meteorite shape, a columnar plate shape, or a hexagonal columnar plate shape.
One of the measures for specifying the particle shape is Wadell's circularity and sphericity, which have been used in the powder industry. Wadell's sphericity s is defined by the following equation. The closer s is to 1, the closer it is to a true sphere.
s = (surface area of a sphere having the same volume as the particle) / (surface area of the particle)
Wadell's circularity c is defined by the following equation. The closer c is to 1, the closer it is to a perfect circle.
c = (peripheral length of a circle equal to the projected area of the particle) / (perimeter of the projected surface of the particle)
本発明において粒子の形状が碁石状（または円盤状とも呼ぶことがある）であるとは、図４のＳＥＭ写真像に示すように短径を回転軸とした回転楕円形状の形状である。具体的には、回転軸の方向から見た粒子の投影像に関して、Ｗａｄｅｌｌの円形度ｃが、０．９５≦ｃ≦１であって、断面である楕円の（短径／長径）の比率ａが０．０５≦ａ≦０．５であることが好ましい。 In the present invention, the shape of the particles is a meteorite shape (or may be referred to as a disk shape) is a spheroid shape having a minor axis as a rotation axis as shown in the SEM photographic image of FIG. Specifically, with respect to the projected image of the particle viewed from the direction of the rotation axis, Wadell's circularity c is 0.95 ≦ c ≦ 1, and the ratio of the ellipse (minor axis / major axis) ratio a Is preferably 0.05 ≦ a ≦ 0.5.
本発明において粒子の形状が六角柱板状であるとは、図５のＳＥＭ写真像のように、扁平な正六角柱様の形状で、上面または下面方向から見た粒子の投影像に関して、Ｗａｄｅｌｌの円形度Ｃが、０．８８≦ｃ＜０．９５の六角形であって、厚さ／（正六角形の対角線長さ）の比率ｂが０．０５≦ｂ≦０．６であることが好ましい。 In the present invention, the shape of the particles is a hexagonal columnar plate shape, which is a flat regular hexagonal column-like shape as in the SEM photographic image of FIG. It is preferable that the circularity C is a hexagon with 0.88 ≦ c <0.95, and the ratio b of thickness / (diagonal length of regular hexagon) is 0.05 ≦ b ≦ 0.6. .
本発明において粒子の形状が円柱板状であるとは、図６のＳＥＭ写真のように、扁平な円柱様の形状で、上面または下面方向から見た粒子の投影像に関して、Ｗａｄｅｌｌの円形度ｃが、０．９５≦ｃ≦１の円形であって、厚さ／（円の直径）の比率ｄが０．０５≦ｄ≦０．６であることが好ましい。 In the present invention, the shape of the particles is a cylindrical plate shape, as shown in the SEM photograph of FIG. 6, a flat cylindrical shape, and Wadell's circularity c with respect to the projected image of the particles viewed from the upper surface or the lower surface direction. However, it is preferable that 0.95 ≦ c ≦ 1 and the thickness / (circle diameter) ratio d is 0.05 ≦ d ≦ 0.6.
本発明に用いる無機粒子のもうひとつの特徴は、その粒子径分布のシャープ度（Ｄ７５／Ｄ２５）が１．０≦Ｄ７５／Ｄ２５≦１．４を満足することである。
ここで、粒子径分布のシャープ度（Ｄ７５／Ｄ２５）とは、粉体工業分野でしばしば用いられる粒子径均一性の評価方法である。これは、横軸に粒子径、縦軸に累積度数をとり、全粒子個数に対し、粒子径の小さいものから累積度数が２５％になる粒子径をＤ２５、７５％になる粒子径をＤ７５としたとき、これらの比の値Ｄ７５／Ｄ２５によって定義される。
Another feature of the inorganic particles used in the present invention is that the sharpness (D75 / D25) of the particle size distribution satisfies 1.0 ≦ D75 / D25 ≦ 1.4.
Here, the sharpness (D75 / D25) of the particle size distribution is an evaluation method of particle size uniformity often used in the powder industry. The horizontal axis is the particle diameter, the vertical axis is the cumulative frequency, and the total particle number is D25, the particle diameter from which the cumulative frequency is 25% to the total particle number is D25, and the particle diameter at 75% is D75. Is defined by these ratio values D75 / D25.
本発明において無機粒子は、粒子径分布のシャープ度（Ｄ７５／Ｄ２５）が粒子形状にかかわらず１≦Ｄ７５／Ｄ２５≦１．４の範囲の値を示すことが好ましい。さらに好ましくは１．０２≦Ｄ７５／Ｄ２５≦１．３であり、最も好ましくは１．０５≦Ｄ７５／Ｄ２５≦１．２である。
粒子径の均一性の他の評価方法としては、半値幅、標準偏差および変動係数等で評価することも可能であり、これら評価方法には、互いに相関関係があり、Ｄ７５／Ｄ２５、半値幅および標準偏差のうちどれを評価基準にしても差し支えない。
In the present invention, the inorganic particles preferably have a sharpness of particle size distribution (D75 / D25) in the range of 1 ≦ D75 / D25 ≦ 1.4 regardless of the particle shape. More preferably, 1.02 ≦ D75 / D25 ≦ 1.3, and most preferably 1.05 ≦ D75 / D25 ≦ 1.2.
As other evaluation methods for the uniformity of the particle diameter, it is also possible to evaluate by half width, standard deviation, coefficient of variation, etc., and these evaluation methods are correlated with each other, and D75 / D25, half width and Any standard deviation can be used as the evaluation standard.
本発明者らは、粒子径分布のシャープ度と、光拡散効果および全光線透過率の関係を以下のように考えている。粒子径分布のシャープ度が上記範囲内であれば、光拡散層内で粒子が均一に分散し、各粒子が一定方向、即ち板状粒子が光拡散層の上面あるいは下面に平行に配向するため、高い光拡散効果および全光線透過率が得られる。一方、粒子径分布のシャープ度が上記範囲外である場合には、粒子形状が碁石状、円柱板状もしくは六角柱板状であっても、拡散層内において粒子が均一に分散せず、粒子配列方向が一定にならないため、上記の様な効果は得られない。
その形状が碁石状、円柱板状もしくは六角柱板状を呈し、かつ粒子径分布のシャープ度（Ｄ７５／Ｄ２５）が１≦Ｄ７５／Ｄ２５≦１．４の範囲の無機粒子としては、例えば下記式（１）で表わされるアルミニウム塩水酸化物粒子が例示できる。
The present inventors consider the relationship between the sharpness of the particle size distribution, the light diffusion effect, and the total light transmittance as follows. If the sharpness of the particle size distribution is within the above range, the particles are uniformly dispersed in the light diffusion layer, and each particle is oriented in a certain direction, that is, the plate-like particles are parallel to the upper surface or the lower surface of the light diffusion layer. High light diffusion effect and total light transmittance can be obtained. On the other hand, when the sharpness of the particle size distribution is outside the above range, even if the particle shape is a meteorite shape, a cylindrical plate shape, or a hexagonal column shape, the particles are not uniformly dispersed in the diffusion layer. Since the arrangement direction is not constant, the above effects cannot be obtained.
Examples of inorganic particles having a meteorite shape, a cylindrical plate shape, or a hexagonal columnar plate shape, and a sharpness of particle size distribution (D75 / D25) in the range of 1 ≦ D75 / D25 ≦ 1.4 include, for example, The aluminum salt hydroxide particles represented by (1) can be exemplified.
（式中Ｍは、Ｎａ＋、Ｋ＋、ＮＨ４＋、Ｈ３Ｏ＋およびＣａ２＋からなる群より選ばれる少なくとも１種を含む陽イオンであり、含有重量においてＮａ＋＞＞Ｋ＋、ＮＨ４＋、Ｈ３Ｏ＋、Ｃａ２＋である。Ｍ′はＺｎ２＋、Ｃｕ２＋、Ｎｉ２＋、Ｓｎ４＋、Ｚｒ４＋およびＴｉ４＋からなる群から選ばれる少なくとも１種の金属陽イオン、Ａは少なくとも１種の有機酸アニオン、Ｂは少なくとも１種の無機酸アニオンを表わし、式中ａ、ｂ、ｍ、ｎ、ｘ、ｙおよびｚは、０．７≦ａ≦１．３５、２．７≦ｂ≦３．３、０≦ｍ≦５、４≦ｎ≦７、０≦ｘ≦０．６、１．７≦ｙ≦２．４、０≦ｚ≦０．５である）
上記式（１）においてＡで表される有機酸アニオンは、有機カルボン酸または有機オキシカルボン酸にもとづくアニオンから選ばれる少なくとも１種であることが好ましい。より好ましくは、炭素数１〜１５の有機カルボン酸または炭素数１〜１５の有機オキシカルボン酸にもとづくアニオンから選ばれる少なくとも１種であることが好ましい。さらに好ましくは、炭素数が２〜１０でありカルボキシル基を１〜４個有する有機カルボン酸または炭素数が２〜１０でありオキシカルボキシル基を１〜４個有する有機オキシカルボン酸にもとづくアニオンから選ばれる少なくとも１種である。最も好ましくは、シュウ酸、クエン酸、酒石酸、林檎酸、没食子酸、グリセリン酸および乳酸から選ばれる少なくとも１種にもとづくアニオンである。
(In the formula, M is a cation containing at least one selected from the group consisting of Na + , K + , NH 4+ , H 3 O + and Ca 2+ , and Na + >> K + , NH 4+ in content weight) H 3 O + , Ca 2+ , M ′ is at least one metal cation selected from the group consisting of Zn 2+ , Cu 2+ , Ni 2+ , Sn 4+ , Zr 4+ and Ti 4+ , and A is at least one In which B represents at least one inorganic acid anion, and a, b, m, n, x, y and z are 0.7 ≦ a ≦ 1.35, 2.7 ≦ b ≦. 3.3, 0 ≦ m ≦ 5, 4 ≦ n ≦ 7, 0 ≦ x ≦ 0.6, 1.7 ≦ y ≦ 2.4, 0 ≦ z ≦ 0.5)
The organic acid anion represented by A in the above formula (1) is preferably at least one selected from anions based on organic carboxylic acids or organic oxycarboxylic acids. More preferably, it is preferably at least one selected from an anion based on an organic carboxylic acid having 1 to 15 carbon atoms or an organic oxycarboxylic acid having 1 to 15 carbon atoms. More preferably, it is selected from an organic carboxylic acid having 2 to 10 carbon atoms and 1 to 4 carboxyl groups or an anion based on an organic oxycarboxylic acid having 2 to 10 carbon atoms and 1 to 4 oxycarboxyl groups. At least one kind. Most preferred is an anion based on at least one selected from oxalic acid, citric acid, tartaric acid, apple acid, gallic acid, glyceric acid and lactic acid.
上記式（１）においてＢで表される無機酸アニオンは、具体的には、硫酸イオン、硝酸イオン、燐酸イオンおよびケイ酸イオンから選ばれる少なくとも１種であることが好ましい。さらに好ましくは、硫酸イオンおよび硝酸イオンから選ばれる少なくとも１種である。
上記式（１）においてＭは、Ｎａ＋、Ｋ＋、ＮＨ４＋およびＨ３Ｏ＋およびＣａ２＋なる群から選ばれた少なくとも１種を含む陽イオンであり、好ましい態様ではＮａ＋である。Ｍ’は、Ｚｎ２＋、Ｃｕ２＋、Ｎｉ２＋、Ｓｎ４＋、Ｚｒ４＋およびＴｉ４＋からなる群から選ばれる少なくとも１種の金属陽イオンである。
無機粒子は国際公開第０５／０８５１６８号パンフレットまたは国際公開第０６／１０９８４７号パンフレットに記載された方法によって製造することができる。
Specifically, the inorganic acid anion represented by B in the above formula (1) is preferably at least one selected from sulfate ion, nitrate ion, phosphate ion and silicate ion. More preferably, it is at least one selected from sulfate ions and nitrate ions.
In the above formula (1), M is a cation containing at least one selected from the group consisting of Na + , K + , NH 4+ and H 3 O + and Ca 2+ , and is Na + in a preferred embodiment. M ′ is at least one metal cation selected from the group consisting of Zn 2+ , Cu 2+ , Ni 2+ , Sn 4+ , Zr 4+ and Ti 4+ .
The inorganic particles can be produced by the method described in International Publication No. 05/085168 or International Publication No. 06/109847.
碁石状（円盤状）粒子は、国際公開第０５／０８５１６８号パンフレットの第２１ページ第１９〜２６行に記載の方法により製造することができる。即ち、碁石状（円盤状）粒子は、式（１）におけるＢの無機酸イオンが硫酸イオンの場合、硫酸アルミニウムと（１）式におけるＭ’の硫酸塩と、Ｍの硫酸塩および有機酸および／または有機酸塩、例えば蓚酸（Ｈ２Ｃ２Ｏ４）の混合溶液に、当該Ｍを含む水酸化アルカリ水溶液を添加して加熱反応させることによって生成させることができる。具体的には、国際公開第０５／０８５１６８号パンフレットの第１８ページ実施例１−Ｂ、第１９ページ実施例１−Ｇ、第２０ページ実施例１−Ｈおよび第２１ページ実施例１−Ｔ等に記載された方法によって製造することができる。
同号パンフレットの実施例１−Ｂによれば、０．２ｍｏｌの硫酸アルミニウム、０．２ｍｏｌの硫酸ナトリウムを６００ｍｌの純水に溶解させ、０．０１５ｍｏｌの蓚酸を入れる。次に攪拌しながら、混合液に０．８ｍｏｌの水酸化ナトリウムを添加し、１７０℃で８時間水熱処理を行う。冷却した液を濾過水洗し、９５℃で１５時間乾燥処理することにより、円盤状を呈するＮａ１．０２Ａｌ３（ＳＯ４）２．０３（Ｃ２Ｏ４）０．０６（ＯＨ）５．８４・０．２Ｈ２Ｏを合成することができる。
Meteorite-like (disk-like) particles can be produced by the method described on page 21, lines 19 to 26 of WO05 / 085168. That is, when the inorganic acid ion of B in Formula (1) is a sulfate ion, meteorite-like (disk-like) particles are composed of aluminum sulfate, M ′ sulfate in Formula (1), M sulfate and organic acid, and It can be produced by adding an alkali hydroxide aqueous solution containing M to a mixed solution of an organic acid salt, for example, oxalic acid (H 2 C 2 O 4 ), and heating the mixture. Specifically, 18th page Example 1-B, 19th page Example 1-G, 20th page Example 1-H, 21st page Example 1-T of International Publication No. 05/085168 pamphlet, etc. It can be produced by the method described in 1.
According to Example 1-B of the same pamphlet, 0.2 mol of aluminum sulfate and 0.2 mol of sodium sulfate are dissolved in 600 ml of pure water, and 0.015 mol of oxalic acid is added. Next, 0.8 mol of sodium hydroxide is added to the mixed solution while stirring, and hydrothermal treatment is performed at 170 ° C. for 8 hours. 4. The cooled liquid is washed with filtered water, and dried at 95 ° C. for 15 hours to give a disk-like Na 1.02 Al 3 (SO 4 ) 2.03 (C 2 O 4 ) 0.06 (OH) . 84 · 0.2H 2 O can be synthesized.
六角柱板状粒子は、国際公開第０５／０８５１６８号パンフレットの第１９ページ実施例１−Ｆに記載された方法によって製造することができる。同パンフレットの実施例１−Ｆによれば、０．２ｍｏｌの硫酸アルミニウム、０．２ｍｏｌ硫酸ナトリウムを６００ｍｌの純水に溶解させ、０．０２５ｍｏｌの蓚酸を入れる。次に攪拌しながら、前記混合液に水酸化ナトリウム水溶液１８０ｍｌ（０．９ｍｏｌ）を添加し、室温で３０分攪拌したのち、１８０℃で２０時間の水熱処理を行う。冷却した液を濾過水洗し、９５℃で１５時間乾燥処理することにより六角板状のＮａ０．９３Ａｌ３（ＳＯ４）２．０１（Ｃ２Ｏ４）０．０９２（ＯＨ）５．７３・０．２Ｈ２Ｏを合成することができる。
円柱板状粒子は、国際公開第０６／１０９８４７号パンフレットの第３３ページ実施例１−Ｆ、第３４ページ実施例１−Ｋ、第３６ページ実施例１−Ｏおよび１−Ｐ等に記載された方法によって製造することができる。
例えば、同号パンフレットの実施例１−Ｆによれば、１Ｌ容器に１．０３モル／Ｌの硫酸アルミニウム水溶液８７ｍｌと硫酸ナトリウム１２．７８ｇ（０．０９ｍｏｌ）を入れ脱イオン水で５００ｍｌにし、室温においてホモミキサーで攪拌しつつＺｎＯ（市販品）粉末５．５３ｇを加え、２０分間攪拌後、３．３８５Ｎの水酸化ナトリウム水溶液４７ｍｌを注加する。更に、２０分間攪拌後、オートクレーブ装置に移して、１７０℃で２時間水反応さる。その後、冷却後、炉別、水洗し、１０５℃で１８時間乾燥させ、円柱板状を呈するＮａ１．０９（Ａｌ２．８０，Ｚｎ０．２０）（ＳＯ４）２．２７（ＯＨ）５．３５・１．３３Ｈ２Ｏを合成することができる。
Hexagonal columnar particles can be produced by the method described in Example 1-F on page 19 of WO 05/085168. According to Example 1-F of the pamphlet, 0.2 mol of aluminum sulfate and 0.2 mol of sodium sulfate are dissolved in 600 ml of pure water, and 0.025 mol of oxalic acid is added. Next, 180 ml (0.9 mol) of an aqueous sodium hydroxide solution is added to the mixed solution while stirring, and after 30 minutes of stirring at room temperature, hydrothermal treatment is performed at 180 ° C. for 20 hours. The cooled liquid was washed with filtered water and dried at 95 ° C. for 15 hours to give hexagonal plate-like Na 0.93 Al 3 (SO 4 ) 2.01 (C 2 O 4 ) 0.092 (OH) 5.73 · 0.2 H 2 O can be a synthesized.
Cylindrical plate-like particles were described in, eg, International Publication No. 06/109847, page 33, Example 1-F, page 34, Example 1-K, page 36, Examples 1-O and 1-P. It can be manufactured by a method.
For example, according to Example 1-F of the same pamphlet, 87 ml of 1.03 mol / L aluminum sulfate aqueous solution and 12.78 g (0.09 mol) of sodium sulfate are placed in a 1 L container to 500 ml with deionized water, While stirring with a homomixer, 5.53 g of ZnO (commercially available) powder was added, and after stirring for 20 minutes, 47 ml of a 3.385N aqueous sodium hydroxide solution was poured. Further, after stirring for 20 minutes, the mixture is transferred to an autoclave apparatus and subjected to water reaction at 170 ° C. for 2 hours. Then, after cooling, washed by furnace, washed with water, dried at 105 ° C. for 18 hours, and Na 1.09 (Al 2.80, Zn 0.20 ) (SO 4 ) 2.27 (OH) 5 exhibiting a cylindrical plate shape. .35 · 1.33H 2 O can be synthesized.
以上例示した碁石状、円柱板状もしくは六角柱板状を呈する無機粒子は、中空または多孔質にすることによって上記粒子と同等またはそれ以上の効果を示す。該中空または多孔質の碁石状、円柱板状もしくは六角柱板状を呈する無機粒子は、例えば特開２００７−２０４２９３号公報の段落００２１に記載されたように、式（１）で表されるアルミニウム塩水酸化物粒子の懸濁液に酸またはアルカリ水溶液を滴下し、加熱反応させたのち、冷却、濾別、水洗および乾燥することに得ることができる。具体的には、同号公報の段落００６４に実施例１として記載された方法により製造することができる。 The inorganic particles having a meteorite shape, a cylindrical plate shape, or a hexagonal columnar shape exemplified above exhibit an effect equal to or greater than that of the above particles by making them hollow or porous. The inorganic particles exhibiting the hollow or porous meteorite shape, columnar plate shape or hexagonal columnar shape are, for example, aluminum represented by the formula (1) as described in paragraph 0021 of JP-A-2007-204293. It can be obtained by dropping an acid or alkali aqueous solution into a suspension of salt hydroxide particles, causing a reaction by heating, cooling, filtering, washing with water and drying. Specifically, it can be produced by the method described as Example 1 in paragraph 0064 of the publication.
本発明に使用する無機粒子の平均二次粒子径は、０．１〜５μｍの範囲であることが好ましく、より好ましい範囲は１〜５μｍである。
光拡散層中の無機粒子の含有量は、樹脂バインダ１００重量部に対し、好ましくは０．１〜２００重量部、さらに好ましくは１０〜２００重量部、より好ましくは１００〜２００重量部である。
The average secondary particle diameter of the inorganic particles used in the present invention is preferably in the range of 0.1 to 5 μm, more preferably 1 to 5 μm.
The content of the inorganic particles in the light diffusion layer is preferably 0.1 to 200 parts by weight, more preferably 10 to 200 parts by weight, and more preferably 100 to 200 parts by weight with respect to 100 parts by weight of the resin binder.
（樹脂）
樹脂は、アクリル樹脂であることが好ましく、熱硬化性または光硬化性アクリル樹脂を用いることもできる。アクリル樹脂を例示すると、ポリアクリル酸およびそのエステル、ポリメタクリル酸およびそのエステル等である。
′（平均傾き度〈θｔ〉）
本発明において、光拡散層内における無機粒子の平均傾き度〈θｔ〉は、０°≦〈θｔ〉≦１５°を満足することが好ましい。無機粒子の平均傾き度〈θｔ〉は、各粒子が光拡散層内において光拡散層の上面あるいは下面に平行に配向しているかどうかを表す尺度である。これは、板状粒子の上面または下面と光拡散層の上面あるいは下面のなす角度の平均で表される。円盤状粒子の場合は、図１２の正面図の基準面Ａ−Ａ’を含む紙面に垂直な面（基準面と呼ぶ）と光拡散層の上面あるいは下面のなす角度で表される。
具体的には、光拡散層を視野に含む１００００倍のＳＥＭ写真において、任意の２０個の無機粒子につき、それぞれ傾き度θｔを測定して平均した値である。
高い光拡散効果および全光線透過率が得るためには、〈θｔ〉は、０°≦〈θｔ〉≦１５°であることがより好ましく、最も好ましくは０°≦〈θｔ〉≦１２°である。〈θｔ〉が１５°を超えると全光線透過率が低下するので好ましくない。
(resin)
The resin is preferably an acrylic resin, and a thermosetting or photocurable acrylic resin can also be used. Examples of the acrylic resin include polyacrylic acid and its ester, polymethacrylic acid and its ester, and the like.
′ (Average inclination degree <θ t >)
In the present invention, the average inclination <θ t > of the inorganic particles in the light diffusion layer preferably satisfies 0 ° ≦ <θ t > ≦ 15 °. The average inclination degree <θ t > of the inorganic particles is a scale representing whether each particle is oriented in parallel with the upper surface or the lower surface of the light diffusion layer in the light diffusion layer. This is expressed as an average of the angle formed by the upper or lower surface of the plate-like particle and the upper or lower surface of the light diffusion layer. In the case of disk-shaped particles, it is represented by an angle formed by a plane (referred to as a reference plane) perpendicular to the paper plane including the reference plane AA ′ in the front view of FIG. 12 and the upper or lower surface of the light diffusion layer.
Specifically, it is a value obtained by measuring and averaging the inclination degree θ t for each of 20 arbitrary inorganic particles in a 10,000 times SEM photograph including the light diffusion layer in the field of view.
In order to obtain a high light diffusion effect and a total light transmittance, <θ t > is more preferably 0 ° ≦ <θ t > ≦ 15 °, and most preferably 0 ° ≦ <θ t > ≦ 12. °. If <θ t > exceeds 15 °, the total light transmittance decreases, which is not preferable.
（基材）
本発明に用いる基材は、ＪＩＳ Ｋ ７１３６にもとづく方法で測定した全光線透過率が８０〜１００％、かつヘーズが０〜５％であることが好ましく、全光線透過率が９０〜１００％、かつヘーズが０〜１％であればより好ましい。
ただし、用途によってはさらにヘーズの大きな基材を用いてもよい。
好適に用いることができる基材としては、ガラス、ポリカーボネート、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリプロピレン、ポリエチレン、アセチルセルロース、塩化ビニル系樹脂等が挙げられる。
また、バインダとフィルムの接着強度を考慮すると、基材表面にはコロナ処理や他の親水化処理が施されていることが好ましい。
基材の厚みは１０〜２０００μｍの範囲であることが好ましい。より好ましくは３０〜１０００μｍの範囲である。１０μｍより薄いと取り扱いが非常に困難となり、２０００μｍより厚いと剛性が大きい上、吸湿や温度変化による経時的変形に起因する干渉縞や明暗が発生しやすく好ましくない。
(Base material)
The substrate used in the present invention preferably has a total light transmittance of 80 to 100% and a haze of 0 to 5% as measured by a method based on JIS K 7136, and a total light transmittance of 90 to 100%. And it is more preferable if haze is 0 to 1%.
However, a substrate having a larger haze may be used depending on the application.
Examples of the substrate that can be suitably used include glass, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polypropylene, polyethylene, acetylcellulose, and vinyl chloride resin.
In consideration of the adhesive strength between the binder and the film, the surface of the base material is preferably subjected to corona treatment or other hydrophilic treatment.
The thickness of the substrate is preferably in the range of 10 to 2000 μm. More preferably, it is the range of 30-1000 micrometers. If it is thinner than 10 μm, handling becomes very difficult, and if it is thicker than 2000 μm, the rigidity is high, and interference fringes and light / dark due to time-dependent deformation due to moisture absorption and temperature change are likely to occur.
（光拡散構造体の製造）
本発明の光拡散構造体は、無機粒子を樹脂バインダに分散させた光拡散剤を、基材の少なくとも表（オモテ）面に光拡散層として積層して得られる。ここでいう表（オモテ）面とは、基材の、光源と反対側の面である。さらに、表（オモテ）面に加えて、基材の裏面にも光拡散層を積層することによりヘーズを増大させることができる。光拡散剤は溶媒を含有することが好ましい。
光拡散剤は、樹脂バインダ１００重量部に対し無機粒子を好ましくは０．１〜２００重量部配合してなる。さらに好ましい配合量は１０〜２００重量部、最も好ましい配合量は１００〜２００重量部である。
(Manufacture of light diffusion structure)
The light diffusing structure of the present invention is obtained by laminating a light diffusing agent in which inorganic particles are dispersed in a resin binder as a light diffusing layer on at least the front (front) surface of a substrate. The front (front) surface here is the surface of the substrate opposite to the light source. Furthermore, in addition to the front (front) surface, haze can be increased by laminating a light diffusion layer on the back surface of the substrate. The light diffusing agent preferably contains a solvent.
The light diffusing agent is preferably formed by blending 0.1 to 200 parts by weight of inorganic particles with respect to 100 parts by weight of the resin binder. A more preferable amount is 10 to 200 parts by weight, and a most preferable amount is 100 to 200 parts by weight.
ただし、表（オモテ）面のみに光拡散層を積層する場合は、無機粒子の好ましい配合量は１００〜２００重量部である。図１から明らかなように、無機粒子の配合量が２００重量部を超えると全光線透過率が７５％未満、またはヘーズが８０％未満になるため好ましくない。一方、無機粒子の配合量が１００重量部未満であると隠蔽性が低下するため好ましくない。
樹脂バインダとして熱硬化性または光硬化性アクリル樹脂を用いる場合は、塗布後に光または熱でバインダを硬化して製造することができる。光拡散剤は塗布前に脱泡しておくことが好ましい。
However, when laminating | stacking a light-diffusion layer only on a surface (front) surface, the preferable compounding quantity of an inorganic particle is 100-200 weight part. As apparent from FIG. 1, when the amount of the inorganic particles exceeds 200 parts by weight, the total light transmittance is less than 75% or the haze is less than 80%, which is not preferable. On the other hand, if the blending amount of the inorganic particles is less than 100 parts by weight, the concealability is lowered, which is not preferable.
When a thermosetting or photocurable acrylic resin is used as the resin binder, it can be manufactured by curing the binder with light or heat after coating. The light diffusing agent is preferably defoamed before application.
光拡散層の基材上への積層は、ハケ塗り、ローラー塗り、吹付塗装、エアレススプレー、ロールコート、浸漬塗り、電着塗装、静電塗装、紫外線硬化塗装等の従来公知の塗装方法、もしくはグラビアコート、エアナイフコート、キスコート、スプレーコート、ホイラーコートもしくはグラビア印刷、グラビアオフセット印刷、平版オフセット印刷、ダイリソ印刷、凸版印刷、凹版印刷、シルクスクリーン印刷、静電印刷、インクジェット方式等従来公知のコートまたは印刷方法によって行うことができる。 Lamination of the light diffusing layer on the substrate may be performed by a conventionally known coating method such as brush coating, roller coating, spray coating, airless spray, roll coating, dip coating, electrodeposition coating, electrostatic coating, ultraviolet curable coating, or the like. Gravure coating, air knife coating, kiss coating, spray coating, wheeler coating or gravure printing, gravure offset printing, planographic offset printing, dilithographic printing, letterpress printing, intaglio printing, silk screen printing, electrostatic printing, inkjet printing, etc. This can be done by a printing method.
さらに、前記したような各粒子が一定方向に配向することによる効果を得るためには、グラビアコート、エアナイフコートおよびキスコートによる塗布が好ましい。
光拡散剤の塗布厚は１〜５０μｍの範囲内であることが好ましい。１μｍ未満だとヘーズが低下し、５０μｍを超えると全光線透過率が低下するので好ましくない。塗布方式により塗布量が足りない場合は、２回〜３回コート程度の重ね刷りを行う場合もある。
さらに、光拡散層の硬化または安定化のために、光拡散構造体を、室温または３０〜６０℃程度の温度環境下に１日から２週間程度おき、キュアを行ってもよい。
さらに、必要に応じ基材の片面または両面に、スティッキング防止機能、帯電防止機能、傷つき防止機能または第二の光拡散層機能、反射防止機能等のうち一つ以上を有する層が積層されていてもよい。
Furthermore, in order to obtain the effect obtained by orienting each particle in a certain direction, application by gravure coating, air knife coating, and kiss coating is preferable.
The coating thickness of the light diffusing agent is preferably in the range of 1 to 50 μm. If it is less than 1 μm, the haze decreases, and if it exceeds 50 μm, the total light transmittance decreases, which is not preferable. If the coating amount is insufficient depending on the coating method, overprinting may be performed about 2 to 3 times.
Further, in order to cure or stabilize the light diffusing layer, the light diffusing structure may be cured at room temperature or in a temperature environment of about 30 to 60 ° C. for about 1 day to 2 weeks.
Furthermore, a layer having one or more of an anti-sticking function, an anti-static function, an anti-scratch function, a second light diffusion layer function, an anti-reflection function, or the like is laminated on one side or both sides of the substrate as necessary. Also good.
以下、本発明を実施例により、さらに詳細に説明する。本発明における各種特性の測定は以下の方法で行なった。各測定は常温（２０〜３０℃）、常湿下（６０％ＲＨ以下）で行なった。 Hereinafter, the present invention will be described in more detail with reference to examples. Various characteristics in the present invention were measured by the following methods. Each measurement was performed at normal temperature (20 to 30 ° C.) and normal humidity (60% RH or less).
１．測定方法・装置及び評価方法
（１）透過光度測定
装置：変角光度計ＧＰ−２００（（株）村上色彩技術研究所）
方法：光拡散構造体の裏面側に光源を配置し、表面側において受光器を０〜１８０°の範囲で走査させ、０．１°ごとに透過光量を測定する。ただし、光拡散構造体に関して、光源と受光器が対称の位置に来たときの角度を９０°とする。測定の際は、透過光の強度は最大でも８５以下となるように光電子増倍管の感度を調整する。
1. Measurement method / apparatus and evaluation method (1) Transmittance photometer: Variable angle photometer GP-200 (Murakami Color Research Laboratory)
Method: A light source is disposed on the back side of the light diffusion structure, and the light receiver is scanned in the range of 0 to 180 ° on the front side, and the amount of transmitted light is measured every 0.1 °. However, regarding the light diffusing structure, the angle when the light source and the light receiver are in symmetrical positions is 90 °. At the time of measurement, the sensitivity of the photomultiplier tube is adjusted so that the intensity of transmitted light is 85 or less at the maximum.
（２）光拡散構造体の厚み
光拡散構造体の厚みは、試験片測厚器 ＳＤＡ−２５型（高分子計器（株））を用いて測定した。
(2) Thickness of light diffusing structure The thickness of the light diffusing structure was measured using a test piece thickness measuring instrument SDA-25 type (Polymer Meter Co., Ltd.).
（３）平均二次粒子径の測定
装置：粒度分布計 マイクロトラックＭＴ３３００（Ｌｅｅｄ＆Ｎｏｒｔｒｕｐ Ｉｎｓｔｒｕｍｅｎｔｓ Ｃｏｍｐａｎｙ社製
方法：試料粉末７００ｍｇを０．２ｗｔ％ヘキサメタリン酸ソーダ水溶液７０ｍｌに加えて、超音波で３分間分散処理した後、スターラーで攪拌しながら粒度分布を測定する。
(3) Measuring apparatus of average secondary particle diameter: Particle size distribution analyzer Microtrac MT3300 (Method of Leed & Norrup Instruments Company: 700 mg of sample powder was added to 70 ml of 0.2 wt% sodium hexametaphosphate aqueous solution, and dispersion treatment was performed with ultrasound for 3 minutes. Then, the particle size distribution is measured while stirring with a stirrer.
（４）粒子形状の観察
ＳＥＭ写真により観察した。
装置：走査型電子顕微鏡 Ｓ−３０００Ｎ（日立）
方法：加速電圧１５ｋＶ、作動距離１０ｍｍ、倍率２千倍、１万倍、２万倍
(4) Observation of particle shape It observed with the SEM photograph.
Apparatus: Scanning electron microscope S-3000N (Hitachi)
Method: Acceleration voltage 15kV, working distance 10mm, magnification 2,000 times, 10,000 times, 20,000 times
（５）屈折率の測定
装置：アッべ屈折計１Ｔ（ＡＴＡＧＯ）
方法：適当な有機溶媒５ｍＬに試料粉末５ｍｇを添加して超音波で１０分間分散させ、透明な部分を主プリズム面に薄膜状に広げて、屈折率を求めた。
(5) Refractive index measuring device: Abbe refractometer 1T (ATAGO)
Method: 5 mg of the sample powder was added to 5 mL of an appropriate organic solvent and dispersed with ultrasound for 10 minutes, and the transparent portion was spread out in a thin film on the main prism surface to obtain the refractive index.
（６）Ｘ線回折の分析
装置：ＲＩＮＴ２２００ＶＸ線回折システム（理学電機（株）製）
方法：ＣＵ−Ｋα、角度（２θ）：５〜６５°、ステップ：０．０２°、スキャンスピ−ド：４°／分、管電圧：４０ｋＶ、管電流：２０ｍＶ。
(6) X-ray diffraction analyzer: RINT2200V X-ray diffraction system (manufactured by Rigaku Corporation)
Method: CU-Kα, angle (2θ): 5 to 65 °, step: 0.02 °, scan speed: 4 ° / min, tube voltage: 40 kV, tube current: 20 mV.
（７）全光線透過率およびヘーズの測定
装置：オートマチックヘーズメーター ＴＣ−Ｈ３ＤＰ （東京電色）
方法：ＪＩＳ−Ｋ７１３６（ＩＳＯ１４７８２）に基づく
(7) Total light transmittance and haze measuring device: automatic haze meter TC-H3DP (Tokyo Denshoku)
Method: Based on JIS-K7136 (ISO14782)
（８）平均傾き度〈θｔ〉
光拡散層を視野に含む１００００倍のＳＥＭ写真において、任意の２０個の無機粒子につき、粒子の上面または下面と光拡散層の上面あるいは下面のなす傾き度を測定して平均した。
(8) Average slope <θ t >
In a 10,000 times SEM photograph including the light diffusion layer in the field of view, the degree of inclination formed by the upper or lower surface of the particle and the upper or lower surface of the light diffusion layer was measured and averaged for any 20 inorganic particles.
＜無機粒子の調製＞
無機粒子は以下に記す方法で合成し、または市販の無機粒子を用いた。
<Preparation of inorganic particles>
The inorganic particles were synthesized by the method described below, or commercially available inorganic particles were used.
（合成例１：無機粒子Ａ）
１６０ｍｏＬの硫酸アルミニウムおよび０．２ｍｏＬの硫酸ナトリウムを７００Ｌのイオン交換水に溶解させ、これにシュウ酸（Ｈ２Ｃ２Ｏ４）０．１ｍｏＬを加え１ｍ３の反応槽で攪拌した。さらに攪拌羽根の回転速度８９ｒｐｍで攪拌しながら前記混合溶液に水酸化ナトリウム６３３ｍｏＬを添加して１７０℃で３時間水熱処理をおこなった。冷却した反応液をろ過・水洗したのち１２０℃で２４時間乾燥処理および粉砕した結果、図４のＳＥＭ写真に示す円盤状（碁石状）のアルミニウム塩水酸化物粒子（無機粒子Ａ）を得た。無機粒子Ａの諸特性を表１に示す。
(Synthesis Example 1: Inorganic particles A)
160 mol of aluminum sulfate and 0.2 mol of sodium sulfate were dissolved in 700 L of ion-exchanged water, 0.1 mol of oxalic acid (H 2 C 2 O 4) was added thereto, and the mixture was stirred in a 1 m 3 reaction vessel. Further, 633 moL of sodium hydroxide was added to the mixed solution while stirring at a rotational speed of 89 rpm, and hydrothermal treatment was performed at 170 ° C. for 3 hours. The cooled reaction liquid was filtered and washed with water, followed by drying at 120 ° C. for 24 hours and pulverization. As a result, disk-shaped (meteorite) aluminum salt hydroxide particles (inorganic particles A) shown in the SEM photograph of FIG. 4 were obtained. Various characteristics of the inorganic particles A are shown in Table 1.
（合成例２：無機粒子Ｂ）
イオン交換水の量を１０００Ｌ、攪拌羽根の回転速度を７６ｒｐｍにした以外は合成例１と同様の方法により、無機粒子Ｂを得た。
(Synthesis Example 2: Inorganic particles B)
Inorganic particles B were obtained by the same method as in Synthesis Example 1 except that the amount of ion-exchanged water was 1000 L and the rotation speed of the stirring blade was 76 rpm.
（合成例３：無機粒子Ｃ）
イオン交換水の量を１０００Ｌ、攪拌羽根の回転速度を４９ｒｐｍにした以外は無機粒子合成例１と同様の方法により、無機粒子Ｃを得た。
(Synthesis Example 3: Inorganic Particle C)
Inorganic particles C were obtained in the same manner as in the inorganic particle synthesis example 1 except that the amount of ion-exchanged water was 1000 L and the rotation speed of the stirring blade was 49 rpm.
（合成例４：無機粒子Ｄ、ＨおよびＥ）
また、国際公開第０５／０８５１６８号パンフレットの実施例１−Ｆ、１−Ａおよび国際公開第０６／１０９８４７の実施例１−Ｆに記載された方法にもとづいてそれぞれ六角柱板状、球状および円柱板状の無機粒子Ｄ、ＨおよびＥを合成した。これらのうち無機粒子Ｈは比較例として用いた。無機粒子ＤのＳＥＭ写真を図６に示す。無機粒子ＥのＳＥＭ写真を図５に示す。無機粒子ＨのＳＥＭ写真を図７に示す。
(Synthesis Example 4: Inorganic particles D, H and E)
Also, hexagonal columnar plates, spheres, and cylinders were used based on the methods described in Examples 1-F and 1-A of WO05 / 085168 and Example 1-F of WO06 / 109847, respectively. Plate-like inorganic particles D, H and E were synthesized. Of these, inorganic particles H were used as comparative examples. An SEM photograph of the inorganic particles D is shown in FIG. An SEM photograph of the inorganic particles E is shown in FIG. A SEM photograph of the inorganic particles H is shown in FIG.
（合成例５：無機粒子Ｆ）
特開２００７−２０４２９３号公報の段落００６４の実施例１に記載された方法にもとづき、無機粒子Ａを「ブランクＡ」として用いて、無機粒子Ｆを得た。得られた粒子は、ＢＥＴ比表面積が１０２ｍ２／ｇ、全細孔容積が０．２４４ｍｌ／ｇの多孔質中空粒子であった。無機粒子Ｆの諸特性を表２に示す。
(Synthesis Example 5: Inorganic particle F)
Based on the method described in Example 1 of paragraph 0064 of JP 2007-204293 A, inorganic particles F were obtained using inorganic particles A as “blank A”. The obtained particles were porous hollow particles having a BET specific surface area of 102 m 2 / g and a total pore volume of 0.244 ml / g. Various characteristics of the inorganic particles F are shown in Table 2.
（市販品の無機粒子Ｇ、Ｉ、ＪおよびＫ）
さらに、比較例としてそれぞれ無機粒子Ｇ（交差円盤状炭酸カルシウム／（株）ニューライム）、無機粒子Ｉ（シリコーンパウダー商品名：ＫＭＰ−７０１／信越化学工業）、無機粒子Ｊ（シリコーンパウダー商品名：ＫＳＰ−３００／信越化学工業）および無機粒子Ｋ（メチルシリコーンパウダーＭＳＰ−１５００Ｍ／日興リカ）を用いた。各無機粒子の特性を表１および表２に示す。拡散性微粒子ＧのＳＥＭ写真を図８に示す。拡散性微粒子ＩのＳＥＭ写真を図９に示す。
(Commercially available inorganic particles G, I, J and K)
Further, as comparative examples, inorganic particles G (crossed disc-like calcium carbonate / New Lime Co., Ltd.), inorganic particles I (silicone powder trade name: KMP-701 / Shin-Etsu Chemical Co., Ltd.), inorganic particles J (silicone powder trade name: KSP-300 / Shin-Etsu Chemical) and inorganic particles K (methyl silicone powder MSP-1500M / Nikko Rica) were used. The characteristics of each inorganic particle are shown in Table 1 and Table 2. An SEM photograph of the diffusible fine particles G is shown in FIG. An SEM photograph of diffusible fine particles I is shown in FIG.
＜調製例＞
アクリル樹脂２０ｇを（商標名：スミペックスＭＧＳＳ／住友化学（株）製）をトルエン５０ｍＬ、２−ブタノン２０ｍＬおよび酢酸ブチル２０ｍＬの混合溶媒に入れ常温で１昼夜攪拌してポリメタクリル酸溶液を調製した。ポリメタクリル酸溶液に無機粒子Ａ〜Ｋをポリメタクリル酸に加えて光拡散剤を調製した。
<Preparation example>
20 g of acrylic resin (trade name: Sumipex MGSS / manufactured by Sumitomo Chemical Co., Ltd.) was placed in a mixed solvent of 50 mL of toluene, 20 mL of 2-butanone and 20 mL of butyl acetate and stirred at room temperature for one day to prepare a polymethacrylic acid solution. A light diffusing agent was prepared by adding inorganic particles A to K to polymethacrylic acid in a polymethacrylic acid solution.
＜実施例１〜１０、比較例１〜５＞
（光拡散構造体の製造）
定盤の上に大きさ７０ｍｍ×７０ｍｍ×ｔ１００μｍの二軸延伸ポリエステルフィルム（商標名：ダイアホイルＴ６８０Ｅ／三菱化学ポリエステルフィルム）を置いて基材とし、調製例で得られた各光拡散剤を１ｍＬ滴下してアプリケータＹＢＡ−４（ヨシミツ精機）で塗布したのち１０５℃で２時間乾燥して光光拡散構造体を製造した。このとき乾燥後の拡散層厚さが５μｍまたは２５μｍになるように設定した（乾燥後は厚みが塗布時の約１／５になる）。拡散層の厚みは、乾燥後に試験片測厚計で試験片の厚みを計測して基材厚みをもとに算出し、５μｍまたは２５μｍになっていることを確認した。光拡散構造体の製造条件を表３に示す。
<Examples 1 to 10, Comparative Examples 1 to 5>
(Manufacture of light diffusion structure)
A biaxially stretched polyester film (trade name: Diafoil T680E / Mitsubishi Chemical Polyester Film) having a size of 70 mm × 70 mm × t100 μm is placed on a surface plate, and 1 mL of each light diffusing agent obtained in the preparation example is used. It was dropped and applied with an applicator YBA-4 (Yoshimi Seiki), and then dried at 105 ° C. for 2 hours to produce a light-light diffusing structure. At this time, the thickness of the diffusion layer after drying was set to 5 μm or 25 μm (after drying, the thickness was about 1/5 of the coating). The thickness of the diffusion layer was calculated based on the substrate thickness by measuring the thickness of the test piece with a test piece thickness meter after drying, and confirmed that the thickness was 5 μm or 25 μm. Table 3 shows the manufacturing conditions of the light diffusion structure.
（光拡散構造体の特性）
製造した試験片をオートマチックヘーズメーターにセットしてＪＩＳ Ｋ ７１３６にもとづく測定による全光線透過率と散乱透過率を測定してヘーズを算出した。これら各フィルム試験片の諸特性を表３に示す。次に、光拡散構造体の裏面側に光源を配置し、変角光度計を用いて透過光量を測定した。結果を図２および図３に示す。
(Characteristics of light diffusion structure)
The manufactured test piece was set in an automatic haze meter, and the total light transmittance and the scattering transmittance measured by JIS K 7136 were measured to calculate haze. Table 3 shows various characteristics of each film test piece. Next, a light source was disposed on the back side of the light diffusion structure, and the amount of transmitted light was measured using a variable angle photometer. The results are shown in FIG. 2 and FIG.
表３に光拡散構造体Ｎｏ．１〜１０の評価結果として示されているように、本発明の光拡散構造体は、拡散層厚さが５〜２５μｍの範囲であればいずれも全光線透過率が７５％以上、ヘーズも８０％以上である。 Table 3 shows the light diffusion structure no. As shown in the evaluation results of 1 to 10, the light diffusion structure of the present invention has a total light transmittance of 75% or more and a haze of 80 as long as the diffusion layer thickness is in the range of 5 to 25 μm. % Or more.
一方、球状のアルミニウム塩水酸化物粒子を塗布したフィルムＮｏ．１２は全光線透過率が大きいがヘーズが小さく、光拡散構造体としては不適である。
真球状シリコーンパウダーを塗布したフィルムＮｏ．１３〜１５はいずれも全光線透過率が７５％以上、ヘーズも８０％以上である。
光拡散構造体Ｎｏ．６とＮｏ．１４を比較すると、拡散層厚さを２５μｍに増大させた場合、本発明の光拡散構造体Ｎｏ．６についてはヘーズが９５％以上に上昇しているが、真球状シリコーンパウダーを塗布したフィルムＮｏ．１４についてはヘーズが８２％程度に留まり、かつ全光線透過率が７５％未満にまで低下している。
変角光度計を用いて測定した透過光量を示す図２から、本発明の円盤状無機粒子を用いた光拡散構造体Ｎｏ．５〜７（実施例５〜７）では正面を０°として、半値幅が３°（９０°方向の透過光量を１として０．５の透過光量になる角度の幅）以内であることから、拡散透過光を正面に集める効果があることがわかる。また、９０°方向以外の特定の方向への強い光の散乱が見られないので均一な照明が得られる。
On the other hand, film No. 1 coated with spherical aluminum salt hydroxide particles. No. 12 has a large total light transmittance but a small haze and is not suitable as a light diffusion structure.
Film No. coated with true spherical silicone powder 13 to 15 all have a total light transmittance of 75% or more and a haze of 80% or more.
Light diffusion structure No. 6 and no. 14 is compared, when the diffusion layer thickness is increased to 25 μm, the light diffusion structure No. 1 of the present invention. For No. 6, the haze increased to 95% or more. For No. 14, the haze remains at about 82%, and the total light transmittance is reduced to less than 75%.
From FIG. 2 which shows the transmitted light amount measured using the goniophotometer, the light diffusing structure No. 1 using the disc-shaped inorganic particles of the present invention is used. In 5 to 7 (Examples 5 to 7), the front face is 0 °, and the half-value width is within 3 ° (the width of the angle where the transmitted light amount in the 90 ° direction is 1 and the transmitted light amount is 0.5). It can be seen that there is an effect of collecting diffuse transmitted light in front. Further, since no strong light scattering in a specific direction other than the 90 ° direction is observed, uniform illumination can be obtained.
一方、球状のアルミニウム塩水酸化物粒子を用いた光拡散構造体Ｎｏ．１２（比較例２）の場合には、図２から明らかなように半値が１０°であるが正面方向に異常な強いピークを持っている。これは正面から見ると不均一で「ぎらつき」を感じるような照明となる。
また、図３に示すように、無機粒子として真球状シリコーンパウダーを用いた光光拡散構造体Ｎｏ．１３（比較例３）およびＮｏ．１５（比較例５）では、半値幅がそれぞれ１０°以上および５°以上であり透過光を正面に集める効果は本発明の無機粒子に比べて小さく、光拡散構造体Ｎｏ．１４（比較例４）については、上記光光拡散構造体Ｎｏ．１２（比較例２）と同様にぎらつきの問題がある。
On the other hand, light diffusion structure No. 1 using spherical aluminum salt hydroxide particles. In the case of 12 (Comparative Example 2), as is clear from FIG. 2, the half value is 10 °, but has an abnormally strong peak in the front direction. This is a non-uniform illumination when seen from the front and feels “glaring”.
Further, as shown in FIG. 3, a light-light diffusing structure No. 1 using a spherical silicone powder as inorganic particles. 13 (Comparative Example 3) and 15 (Comparative Example 5), the half-value widths are 10 ° or more and 5 ° or more, respectively, and the effect of collecting transmitted light in front is small compared to the inorganic particles of the present invention. 14 (Comparative Example 4), the above light diffusion structure No. As with 12 (Comparative Example 2), there is a problem of glare.
本発明の光拡散構造体において、塗布するバインダの量に対する無機粒子Ｃの配合量（重量部）と、全光線透過率、散乱透過率およびヘーズの値は図１に示すようなグラフになった。図１によれば、無機粒子Ｃの配合量が増加するとともに全光線透過率は低下し、逆にヘーズは増大する。本発明の光拡散構造体は、無機粒子Ｃを最大２００重量部配合しても８０％以上の全光線透過率を維持しているが、２００重量部以上配合してもヘーズ値は大きく上昇しない。
また、配合量が１００重量部未満になるとヘーズが８０％未満になるので好ましくない。
In the light diffusing structure of the present invention, the blending amount (parts by weight) of the inorganic particles C with respect to the amount of the binder to be applied, the total light transmittance, the scattering transmittance, and the haze values are shown in a graph as shown in FIG. . According to FIG. 1, the total light transmittance decreases as the blending amount of the inorganic particles C increases, and conversely, the haze increases. The light diffusing structure of the present invention maintains a total light transmittance of 80% or more even when blending up to 200 parts by weight of the inorganic particles C, but the haze value does not increase significantly even when blended over 200 parts by weight. .
Moreover, since a haze will be less than 80% when a compounding quantity will be less than 100 weight part, it is unpreferable.
光拡散構造体Ｎｏ．６（実施例６）の断面のＳＥＭ写真を図１０に示す。図１０は、光拡散構造体Ｎｏ．６の拡散層部分を１００００倍に拡大したものである。ただし、光拡散層表面は水平に対して反時計周りに４５°傾いて撮影された写真である。図１０の視野内の２０個の粒子（切断時に粒子の脱落した空孔も含む）の平均傾き度は１１．３°であった。
同様の観察を光拡散フィルムＮｏ．１１（比較例１）についても行なった結果を図１２に示す。このときの平均傾き度は３０°以上であった。即ち、粒度分布シャープ度が１．１１である無機粒子Ｂは拡散層内で拡散層上面または下面に平行に近い向きに配向しているが、粒度分布シャープ度が１．７６である無機粒子Ｇは一定の方向に配向しない。
Light diffusion structure No. The SEM photograph of the cross section of No. 6 (Example 6) is shown in FIG. FIG. 10 shows a light diffusion structure no. 6 is obtained by enlarging the diffusion layer portion of 6 times 10,000 times. However, the surface of the light diffusion layer is a photograph taken at an angle of 45 ° counterclockwise with respect to the horizontal. The average inclination degree of 20 particles (including vacancies from which particles were dropped during cutting) in the field of view of FIG. 10 was 11.3 °.
The same observation was made with the light diffusion film No. FIG. 12 shows the result of the measurement for No. 11 (Comparative Example 1). The average inclination at this time was 30 ° or more. That is, the inorganic particles B having a particle size distribution sharpness of 1.11 are oriented in a direction almost parallel to the upper or lower surface of the diffusion layer in the diffusion layer, but the inorganic particles G having a particle size distribution sharpness of 1.76. Are not oriented in a certain direction.
（光拡散構造体の隠蔽性の評価）
外形寸法５０×１００ｍｍ、厚さ１．６ｍｍのアクリル樹脂からなり、表面と対向する裏面が、１００ｍｍの１辺から遠ざかるにつれて肉薄になっており、かつ前記１辺に平行な１０ｍｍ間隔のヘアライン加工でグラデーションパターンの粗面化が施された楔型の導光板の裏面側に反射フィルム（ＲＦ１８８／ツジデン）を両面テープで貼り付け、表面上に作製した各フィルム試験片をのせた。導光板の肉厚側エッジに冷陰極管をセットして管電圧１２００Ｖ，管電流５ｍＡで点灯させた。
(Evaluation of concealment of light diffusion structure)
It is made of acrylic resin with outer dimensions of 50 x 100 mm and thickness of 1.6 mm, and the back surface facing the front surface becomes thinner as it goes away from one side of 100 mm, and the hairline is processed at intervals of 10 mm parallel to the one side. A reflective film (RF188 / Tsujiden) was attached to the back side of a wedge-shaped light guide plate having a roughened gradation pattern, and each film specimen prepared on the surface was placed. A cold cathode tube was set on the thick side edge of the light guide plate and lighted at a tube voltage of 1200 V and a tube current of 5 mA.
続いて、導光板表面から３０ｃｍの距離でグラデーションパターンが明暗の縞として視認されるかどうかを観察することにより光拡散構造体のパターン隠蔽性を評価した。評価は、以下の４段階で評価した。結果を表３に示す。
◎：パターンが全く視認できない。
○：パターンがほぼ視認できない。
△：パターンが少し視認できる。
×：パターンが明確に視認できる。
Subsequently, the pattern hiding property of the light diffusing structure was evaluated by observing whether or not the gradation pattern was visually recognized as bright and dark stripes at a distance of 30 cm from the surface of the light guide plate. Evaluation was performed in the following four stages. The results are shown in Table 3.
A: The pattern is not visible at all.
○: The pattern is almost invisible.
Δ: The pattern is slightly visible.
X: A pattern can be visually recognized clearly.
（耐溶剤性試験）
光拡散構造体表面にイソプロピルアルコールを１滴落とし、室温で５分間放置して蒸発させたのち、隠蔽性の評価と同じ構成のユニットで、導光板表面から３０ｃｍの位置でイソプロピルアルコール滴下跡が視認されるかどうかを観察することにより光拡散構造体の耐溶剤性を評価した。評価は、以下の３段階で評価した。結果を表３に示す。
○：滴下跡がほとんど視認できない。
△：滴下跡が暗くなっているのが少し視認できる。
×：滴下跡が暗くなっているのが明確に視認できる。
(Solvent resistance test)
After dropping 1 drop of isopropyl alcohol on the surface of the light diffusion structure and allowing it to evaporate by leaving it at room temperature for 5 minutes, the isopropyl alcohol dripping trace is visually recognized at a position 30 cm from the light guide plate surface with the same configuration as the evaluation of the concealment property. The solvent resistance of the light diffusing structure was evaluated by observing whether or not it was observed. Evaluation was performed in the following three stages. The results are shown in Table 3.
○: Almost no trace of dripping is visible.
(Triangle | delta): It can visually recognize that the dripping trace is dark a little.
X: It can be visually recognized clearly that the dropping mark is dark.
本発明の光拡散構造体は、液晶パネルのバックライト用光拡散層や液晶プロジェクタ用のスクリーンのような屋内用照明器具のみならず、内照式道路標識および販促用ＰＯＰの光拡散層など屋外用照明器具にも広く使用することができる。 The light diffusing structure of the present invention is used not only for indoor lighting fixtures such as a light diffusing layer for a backlight of a liquid crystal panel and a screen for a liquid crystal projector, but also for outdoor lighting such as a light diffusing layer for internally illuminated road signs and sales promotion POPs. It can also be used widely for lighting equipment.
Claims (6)
無機粒子の形状は、碁石状、円柱板状もしくは六角柱板状であり、その粒子径分布シャープ度（Ｄ７５／Ｄ２５）は１．０≦Ｄ７５／Ｄ２５≦１．４を満足することを特徴とする光拡散構造体。 A light diffusion structure having a base material and a light diffusion layer laminated thereon, the light diffusion layer containing a resin and inorganic particles,
The shape of the inorganic particles is a meteorite shape, a cylindrical plate shape or a hexagonal columnar plate shape, and the particle size distribution sharpness (D 75 / D 25 ) satisfies 1.0 ≦ D 75 / D 25 ≦ 1.4. A light diffusing structure characterized by that.
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| KR101272980B1 (en) | 2010-07-08 | 2013-06-10 | 주식회사 엘지화학 | Light guide plate for led using gravure-offset method, and the process of manufacturing the same |
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| KR102083861B1 (en) * | 2013-12-16 | 2020-03-03 | 동우 화인켐 주식회사 | Light diffusion film |
| CN110927847A (en) * | 2019-12-23 | 2020-03-27 | 宁波长阳科技股份有限公司 | Reflective film and method for producing same |
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| JP2003195015A (en) * | 2001-12-27 | 2003-07-09 | Fuji Photo Film Co Ltd | Optical diffusion film, method for manufacturing the same, polarizing plate and liquid crystal display device |
| WO2005085168A1 (en) * | 2004-03-05 | 2005-09-15 | Kyowa Chemical Industry Co., Ltd. | Particles of aluminum salt hydroxide containing organic acid anion, method for production thereof and use thereof |
| JP2006276839A (en) * | 2005-03-03 | 2006-10-12 | Fuji Photo Film Co Ltd | Optically functional film, its manufacturing method, and polarizing plate using same and image display device |
| JP2007204293A (en) * | 2006-01-31 | 2007-08-16 | Kyowa Chem Ind Co Ltd | Porous particle and method for producing the same |
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| JP4351456B2 (en) * | 2002-03-26 | 2009-10-28 | 恵和株式会社 | Light diffusion sheet and backlight unit using the same |
| WO2006109847A1 (en) * | 2005-04-08 | 2006-10-19 | Kyowa Chemical Industry Co., Ltd. | Alunite compound particle, process for producing the same and use thereof |
| JP2007133173A (en) * | 2005-11-10 | 2007-05-31 | Nippon Shokubai Co Ltd | Light diffusing sheet, complex light diffusing plate, and back light unit using those |
| JP5270171B2 (en) * | 2006-01-24 | 2013-08-21 | 株式会社きもと | Light diffusing sheet |
| CN101118291B (en) * | 2006-08-04 | 2010-04-14 | 鸿富锦精密工业（深圳）有限公司 | Pervasion piece |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2003195015A (en) * | 2001-12-27 | 2003-07-09 | Fuji Photo Film Co Ltd | Optical diffusion film, method for manufacturing the same, polarizing plate and liquid crystal display device |
| WO2005085168A1 (en) * | 2004-03-05 | 2005-09-15 | Kyowa Chemical Industry Co., Ltd. | Particles of aluminum salt hydroxide containing organic acid anion, method for production thereof and use thereof |
| JP2006276839A (en) * | 2005-03-03 | 2006-10-12 | Fuji Photo Film Co Ltd | Optically functional film, its manufacturing method, and polarizing plate using same and image display device |
| JP2007204293A (en) * | 2006-01-31 | 2007-08-16 | Kyowa Chem Ind Co Ltd | Porous particle and method for producing the same |
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| KR101272980B1 (en) | 2010-07-08 | 2013-06-10 | 주식회사 엘지화학 | Light guide plate for led using gravure-offset method, and the process of manufacturing the same |
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| KR20100063668A (en) | 2010-06-11 |
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