Nitto-denko Corporation

Akihiro Nishida

Shuuji Yano

Hiroe Maeda

Kazuki Tsuchimoto

Seiji Kondo

Takashi Kondou

Takezou Hatanaka

Takuya Matsunaga

Takayuki Shigematsu

Seiji Kondou

Ryouji Kinoshita

A polarizing plate of the present invention comprising a polarizer and a protective film provided on at least one surface thereof with an adhesive layer, wherein the protective film comprises (A) a thermoplastic resin having a substituted and/or non-substituted imide group in a side chain and (B) a thermoplastic resin having a substituted and/or non-substituted phenyl group, and nitrile group in a side chain, and the adhesive layer comprises a polyurethane adhesive containing a urethane polyol and an isocyanate crosslinking agent. The polarizing plate exhibits good resistance moisture.

Polarizing plate, adhesive for polarizing plate, optical film and image display device

A light-diffusing sheet includes a transparent film and a light-diffusing layer formed on at least one side of the transparent film. The transparent film contains a thermoplastic resin having a substituted and/or non-substituted imido group in a side chain, and a thermoplastic resin having a substituted and/or non-substituted phenyl group and nitrile group in a side chain, and the surface with the minute unevenness has an average height-depth spacing (Sm): Sm&#x2266;80 &#x3bc;m, a center-line average surface roughness (Ra): Ra&#x2266;0.25 &#x3bc;m and a ten-point average surface roughness (Rz): Rz&#x2266;9Ra.

Light-diffusing sheet, optical element and image display

A light-diffusing sheet includes a transparent film and a light-diffusing layer formed on at least one side of the transparent film. The light-diffusing layer is composed of a resin coating layer having a rough surface. The transparent film contains a thermoplastic resin having a substituted and/or unsubstituted imide group at a side chain and a thermoplastic resin having a substituted and/or unsubstituted phenyl group and a nitrile group at a side chain.

Light-diffusing sheet, optical element and image viewing display

A light diffusing sheet of a structure in which a light diffusing layer is formed on at least one surface of a transparent film, the light diffusing layer including a resin coat layer having a minute unevenness shape and a low refractive index layer having a refractive index lower than that of the resin coat layer on the surface having a minute unevenness shape thereof, whereby the sheet can retain antiglare property, shows almost no white blurring to be recognized due to surface scattering, exhibits almost no birefringence, and is excellent in adherence and durability even when applied to a high definition LCD.

Light diffusing sheet, optical element and image display unit

An optical film in which a retardation film is laminated on one side of a polarizing plate, in which a transparent protective film is laminated on both sides of a polarizer, so that an absorbing axis of the polarizing plate and a slow axis of the retardation film may be perpendicular or may be parallel to each other, wherein a value Nz represented by Nz=(nx&#x2212;nz)/(nx&#x2212;ny) satisfies a range of 0.4 through 0.6, and an in-plane retardation Re=(nx&#x2212;ny)&#xd7;dis 200 through 350 nm, where, a direction of the retardation film in which an in-plane refractive index within the film surface concerned gives a maximum is defined as X-axis, a direction perpendicular to X axis is defined as Y-axis, a thickness direction of the film is defined as Z-axis, refractive indexes in axial direction are defined as nx, ny, nz, respectively, and a thickness of the film is defined as d(nm), and the transparent protective films comprise a thermoplastic saturated norbornene resin, may realize an easily viewable display with high contrast ratio in a wide range when applied to a display system and that may provide a retardation value stabilized under conditions of high temperature or high humidity.

Optical film and display system

An optical film in which a polarizing plate and a retardation film are laminated so that an absorbing axis of the polarizing plate and a slow axis of the retardation film may be perpendicular or may be parallel to each other, wherein a value Nz represented by Nz=(nx&#x2212;nz)/(nx&#x2212;ny) satisfies a range of 0.4 through 0.6, and an in-plane retardation Re=(nx&#x2212;ny)&#xd7;dis 200 through 350 nm, where, a direction of the retardation film in which an in-plane refractive index within the film surface concerned gives a maximum is defined as X-axis, a direction perpendicular to X axis is defined as Y-axis, a thickness direction of the film is defined as Z-axis, refractive indexes in axial direction are defined as nx, ny, nz, respectively, and a thickness of the film is defined as d(nm), may realize an easily viewable display with high contrast ratio in a wide range when applied to a display system, preferably used for a liquid crystal display operating in IPS mode.

An oriented film of polyvinyl alcohol derived film with reduced stretch irregularity and uniform orientation in a wide range of a stretching ratio is obtained by a manufacturing method for an oriented film, comprising the steps of: contacting a non-stretched film, comprising polyvinyl alcohols or derivatives thereof, with moisture percentage adjusted to no more than 10%, to at least one heating roll currently driven and heating the film at no less than 70&#xb0; C.; subsequently giving a tension and stretching using a peripheral velocity difference between the heating roll concerned and a stretch roll in a position ahead of said heating roll in a running direction of the film.

Manufacturing method for oriented film, polarizing film, polarizing plate, and visual display

The present invention provides a polarizing film having a high polarization degree and high transmittance, a process for producing the polarizing film, and a polarizing plate using the polarizing film, and an optical member. In the process for producing the polarizing film, a polyvinyl alcohol-based film is dry-stretched uniaxially, relaxed in an aqueous solution containing iodine or a dichroic dyestuff, and further stretched in an aqueous solution containing a PVA crosslinking agent. It is preferable that the polyvinyl alcohol-based film has a dry-stretch ratio of at least 2, the film after relaxation has a stretch ratio of at least 1.02, and the total stretch ratio is at most 6.5. It is also preferable that the relaxation rate is at most 10% of the dry-stretch ratio.

Process for making a polarizing film

An oriented film with a high degree of orientation may be manufactured even a width of master roll film is wider width, by a manufacturing method for an oriented film, comprising steps of stretching an un-oriented polyvinyl alcohol derived film in dry and in longitudinal uniaxial direction by applying tension produced by peripheral velocity difference between rolls, wherein a value of L/W is not more than 0.6 when a distance between rolls defined as L and a width of the un-oriented polyvinyl alcohol derived film is defined as W; and further heating at 60 to 160&deg; C. after the stretching step.

A polarizer provide that has a high polarization degree and a high transmittance, which is made of a polyvinyl alcohol film, may be produced by a process of producing, comprising the steps of: subjecting a non-stretched polyvinyl alcohol film to uniaxial dry stretching treatment to give a stretch ratio of 4 times or less, dyeing the film, and then subjecting the film to uniaxial stretching treatment to give a stretch ratio of less than 1.5 times under the condition containing a boron compound.

Process of producing a polarizer, polarizer, polarizing plate, and visual display

A polarizer comprising a polyvinyl alcohol based film being dyed by iodine and treated with potassium iodide, wherein an element content ratio (K/I) of iodine (I) and potassium (K) is 0.05 through 0.24, show an effect controlling coloring and satisfying high durability under conditions of high temperature.

Growing community of inventors

Ibaraki, Japan

Akihiro Nishida