Anti-glare sheet for image display device
An anti-glare sheet that exhibits excellent glossy black textures, blackness in dark locations, and anti-glare properties for dynamic images, and that is suited to the implementation of high quality images. The anti-glare sheet has, on at least one surface of a transparent substrate, an anti-glare layer comprising binder resin, diffusion particles, and binder particulates. The transmission intensities of the anti-glare sheet satisfy specific relational equations.
1. An antiglare sheet having an antiglare layer comprising a binder resin, diffusion particles and binder fine particles on at least one side of a transparent base material, the antiglare layer having irregularities on the side opposite the transparent base material, the irregularities being formed by raised sections constituted by the diffusion particles and/or aggregates of the diffusion particles, the diffusion particles being surrounded by a localization layer with high density of the binder fine particles, and the binder fine particles being hydrophobic-treated fumed silica and/or a laminar inorganic compound, wherein the following inequalities (1) and (2) are satisfied to improve blackness in dark surroundings, to improve vivid complexion and blackness, and to prevent an increase of reflection thereby preventing the generation of stray light,
10< Q/U< 36 (1)
Log 10 ( Q 30 /Q )<−6 (2)
wherein Q is a transmission intensity in the direction of regular transmission, when visible light rays have been irradiated on the antiglare sheet perpendicular to the transparent base material side,
wherein Q 30 is the transmission intensity in a direction 30 degrees from the direction of regular transmission, and
wherein U is the mean value of the transmission intensity determined by extrapolation of a straight line connecting the transmission intensity in the direction +2 degrees from the direction of regular transmission with the transmission intensity in the direction +1 degree from the direction of regular transmission, and a straight line connecting the transmission intensity in the direction −2 degrees from the direction of regular transmission with the transmission intensity in the direction −1 degree from the direction of regular transmission, to regular transmission respectively.
2. The antiglare sheet according to claim 1 , wherein the specific gravity of the binder fine particles is greater than the specific gravity of the binder resin.
3. The antiglare sheet according to claim 1 , where the following inequality (3) is satisfied,
3< T< 10 (3)
wherein T (μm) is the thickness of the antiglare layer.
4. The antiglare sheet according to claim 1 , where the following inequality (4) is satisfied,
Log 10 ( Q 20 /Q )<−5.5 (4)
wherein Q is the transmission intensity in the direction of regular transmission, when visible light rays are irradiated perpendicular to the antiglare sheet from the transparent base material side, and
wherein Q 20 is the transmission intensity in the direction 20 degrees from the direction of regular transmission, when visible light rays are irradiated perpendicular to the antiglare sheet from the transparent base material side.
5. The antiglare sheet according to claim 1 , where the following inequality (5) is satisfied,
0≦ Ha−Hi≦ 1.3 (5)
wherein Ha (%) is the total haze value of the antiglare sheet and Hi (%) is the internal haze value of the antiglare sheet.
6. The antiglare sheet according to claim 1 , having a low refractive index layer formed on the uppermost surface layer.
7. A polarizing plate employing the antiglare sheet according to claim 1 .
8. An image display device employing the polarizing plate according to claim 7 .
9. An image display device employing the antiglare sheet according to claim 1 .
10. A method for producing an antiglare sheet comprising a step of providing an antiglare layer comprising a binder resin, diffusion particles and binder fine particles on at least one side of a transparent base material,
wherein the antiglare layer has irregularities on the side opposite the transparent base material, the irregularities are formed by raised sections constituted by the diffusion particles and/or aggregates of the diffusion particles, the diffusion particles are surrounded by a localization layer with high density of the binder fine particles, and the binder fine particles are hydrophobic-treated fumed silica and/or a laminar inorganic compound,
wherein the antiglare sheet is adjusted so as to satisfy the following inequalities (1) and (2) to improve blackness in dark surroundings, to improve vivid complexion and blackness, and to prevent an increase of reflection thereby preventing the generation of stray light,
10< Q/U< 36 (1)
Log 10 ( Q 30 /Q )<−6 (2)
wherein Q is the transmission intensity in the direction of regular transmission, when visible light rays have been irradiated on the antiglare sheet perpendicular to the transparent base material side,
wherein Q 30 is the transmission intensity in a direction 30 degrees from regular transmission, and
wherein U is the mean value of the transmission intensity determined by extrapolation of a straight line connecting the transmission intensity in the direction +2 degrees from the direction of regular transmission with the transmission intensity in the direction +1 degree from the direction of regular transmission, and a straight line connecting the transmission intensity in the direction −2 degrees from the direction of regular transmission with the transmission intensity in the direction −1 degree from the direction of regular transmission, to regular transmission.
11. A method for improving the vivid complexion and blackness, blackness in dark surroundings, antiglare property for dynamic images, glazed black feel and black tightness of an image device,
wherein the image device has on the viewing side of the image display device an antiglare sheet having an antiglare layer comprising a binder resin, diffusion particles and binder fine particles on at least one side of a transparent base material, the antiglare layer having irregularities on the side opposite the transparent base material, the irregularities being formed by raised sections based on the diffusion particles and/or aggregates of the diffusion particles, the diffusion particles being surrounded by a localization layer with high density of the binder fine particles, and the binder fine particles being hydrophobic-treated fumed silica and/or a laminar inorganic compound,
wherein the method comprises a step of controlling the transmission intensities of the antiglare sheet so as to satisfy the following inequalities (1) and (2) to improve blackness in dark surroundings, to improve vivid complexion and blackness, and to prevent an increase of reflection thereby preventing the generation of stray light,
10< Q/U< 36 (1)
Log 10 ( Q 30 /Q )<−6 (2)
wherein Q is the transmission intensity in the direction of regular transmission, when visible light rays have been irradiated on the antiglare sheet perpendicular to the transparent base material side,
wherein Q 30 is the transmission intensity in a direction 30 degrees from the direction of regular transmission, and
wherein U is the mean value of the transmission intensity determined by extrapolation of a straight line connecting the transmission intensity in the direction +2 degrees from the direction of regular transmission with the transmission intensity in the direction +1 degree from the direction of regular transmission, and a straight line connecting the transmission intensity in the direction −2 degrees from the direction of regular transmission with the transmission intensity in the direction −1 degree from the direction of regular transmission, to regular transmission.
12. The method according to claim 11 , wherein the specific gravity of the binder fine particles is greater than the specific gravity of the binder resin.
13. The method according to claim 11 , where the following inequality (3) is satisfied,
3< T< 10 (3)
wherein T (μm) is the thickness of the antiglare layer.
14. The method according to claim 11 , wherein the transmission intensities of the antiglare sheet is controlled so as to satisfy the following inequality (4),
Log 10 ( Q 20 /Q )<−5.5 (4)
wherein Q is the transmission intensity in the direction of regular transmission, when visible light rays are irradiated perpendicular to the antiglare sheet from the transparent base material side, and
wherein Q 20 is the transmission intensity in the direction 20 degrees from the direction of regular transmission, when visible light rays are irradiated perpendicular to the antiglare sheet from the transparent base material side.
15. The method according to claim 11 , where the following inequality (5) is satisfied,
0≦ Ha−Hi≦ 1.3 (5)
wherein Ha (%) is the total haze value of the antiglare sheet and Hi (%) is the internal haze value of the antiglare sheet.
16. The method according to claim 11 , wherein a low refractive index layer is formed on the uppermost surface layer of the antiglare sheet.