1. Field of the Invention
The present invention relates to an anti-reflection film which is arranged for the purpose that external light is prevented from the reflection on the surface of a window, a display, and the like. Particularly, the present invention relates to an anti-reflection film which is arranged on the surface of a display such as a liquid crystal display (LCD), a CRT display, an organic electroluminescence display (ELD), a plasma display (PDP), a surface-conduction electron-emitter display (SED), and a field-emission display (FED).
Particularly, the present invention relates to an anti-reflection film which is arranged on the surface of a liquid crystal display (LCD). Further, the present invention relates to an anti-reflection film which is arranged on the surface of a transmission type liquid crystal display (LCD).
2. Description of the Related Art
In general, displays are used in the environment into which external light and the like enter regardless of whether displays are used in indoor or outdoor. The incident light such as the external light causes regular reflection on the display surface and the like so that the reflected image is mixed with the displayed image and the quality of display screen is reduced. Therefore, it is essential to provide a display surface and the like with an anti-reflection function, and further, improvements of the anti-reflection function as well as a complex of functions other than the anti-reflection function are being demanded.
In general, an anti-reflection function is obtained as a result of the formation of an anti-reflection layer with a multilayer structure which repeatedly has high refractive index layers and low refractive index layers that are made of a transparent material such as metal oxide on a transparent substrate. The anti-reflection layer composed of the multilayer structure can be formed by a dry film-forming method such as chemical vapor deposition (CVD) and physical vapor deposition (PVD).
In the case where an anti-reflection layer is formed by a dry film-forming method, while there is an advantage of finely controlling the thickness of a low refractive index layer and a high refractive index layer, there is a problem of low productivity since the film is formed in a vacuum, which is thus unsuitable for mass production. On the other hand, as a method of forming an anti-reflection layer, the production of anti-reflection film by a wet film-forming method with the use of a coating liquid in which a large area, continuous production, and cost reduction are possible, has been attracting attention.
In addition, in an anti-reflection film in which such anti-reflection layer is arranged on a transparent substrate, the surface is relatively flexible, therefore, in order to give hardness to the surface, a technique in which a hard coat layer that is obtained by curing of an acrylic-based material is arranged and an anti-reflection layer is formed on the hard coat layer is generally used. This hard coat layer is provided with a high level of surface hardness, luster, transparency, and excoriation resistance by the acrylic-based material.
In the case where an anti-reflection layer is formed by a wet film-forming method, the anti-reflection layer is produced with the application of at least a low refractive index layer on a hard coat layer that is obtained by curing of the ionizing radiation curable materials, and the wet film-forming method has a merit of inexpensive production in comparison with a dry film-forming method, and thus, anti-reflection layers produced by such a wet film-forming method are widely distributed in the market.
<Patent document 1>: JP-A-2005-202389.
<Patent document 2>: JP-A-2005-199707.
<Patent document 3>: JP-A-H11-92750.
<Patent document 4>: JP-A-2007-121993.
<Patent document 5>: JP-A-2005-144849.
<Patent document 6>: JP-A-2006-159415.
<Patent document 7>: JP-A-2007-332181.
With the arrangement of an anti-reflection film onto a display surface, by the anti-reflection function of the anti-reflection film, the reflection of external light can be suppressed to improve the contrast of the display in a bright place. Further, the transmittance can be improved at the same time, therefore, an image can be displayed brighter than usual. In addition, the anti-reflection film is also expected to have an energy-saving effect that can suppress the power consumption of the backlight, and the like.
As for an anti-reflection film, an anti-reflection film with low production costs is demanded. Further, an anti-reflection film having excellent anti-reflection performance or excellent optical properties free from interference irregularity is demanded. In addition, an anti-reflection film with high excoriation resistance is demanded since the anti-reflection film is arranged on a display surface. In addition, an anti-reflection film having antistatic function for the prevention of dust adhesion is demanded. In the present invention, the problem to be solved is to provide an anti-reflection film with low production costs, having excellent optical properties and excellent excoriation resistance and antistatic function.