Nitto-denko Corporation

Eiji Hamamoto

Seiichi Kusumoto

Youichirou Sugino

Senri Kondou

Kazuki Tsuchimoto

Hisashi Mihara

Atsushi Kitagawa

Takashi Shouda

Yuji Saiki

The invention relates to a method for producing a polarizer and to a polarizer produced by the production method. The invention also relates to a polarizing plate and an optical film each using the polarizer and to an image display such as a liquid crystal display, an organic electroluminescent display and a plasma display panel, each using the polarizing plate or the optical film. The invention further relates to a cleaning apparatus having a cleaning vessel for use in a cleaning process of a polarizer production method and to a cleaning system into which the cleaning apparatus is assembled.

Method for producing polarizer

A polarizing plate excellent in polarization performance in all wavebands from a short wavelength region to a long wavelength region and a liquid crystal display using such a polarizing plate. The polarizing plate including a polarizer has a portion having a polarization degree of 99% or more at each wavelength of light for wavelengths of 420 to 550 nm and a portion having a polarization degree of 99% or more at each wavelength of light for wavelengths of 550 to 700 nm.

Polarizing plate and liquid crystal display using the same

A polarizer comprising polyvinyl alcohol based films stretched at high stretching ratios stably manufactured: a method for manufacturing including a stretching processing process, a dyeing treatment process, and a boron compounds treatment process to a polyvinyl alcohol film, wherein the stretching processing is performed at least twice so that a total stretching ratio may become 5.5 times or more, and in a second stretching processing or later, wet stretching processing having stretching ratios of 1.2 times or more is performed applying a peripheral velocity difference between a first pinch roll and a second pinch roll, and in the wet stretching processing, a film conveyed out from the first pinch roll is passed on a first guide roll so as to make a holding angle (A) of 120 through 175&#xb0; on a first guide roll to which the film first contacts.

Method for manufacturing polarizer, polarizer, polarizer plate, and image display

A polarizing plate produced according to the present invention includes a polarizing film and a protective layer bonded to a surface of the polarizing film, where the protective layer has no irregularities like record grooves caused by stretching of the polarizing film, so that the polarizing plate with an improved appearance provides clear images even when reflected light is applied. Such a polarizing plate is produced by laminating a protective layer on at least one surface of a polarizer while limiting moisture content of the polarizer to a range from 5% to 30%. A value for the moisture content is obtained by a calculation based on an equation of moisture content (%)=[(A&#x2212;B)/B]&#xd7;100, when A denotes weight of the polarizer before bonding and B denotes weight of the polarizer after being kept in a dryer of 120&#xb0; C. for seven hours.

Method of producing polarizing plate, and liquid crystal display comprising the polarizing plate

A polarizing plate having excellent moisture durability and a liquid crystal display using the same are disclosed. The polarizing plate is produced by covering all surfaces and sides of a polarizer with low moisture-permeable layers having moisture permeability of 310 g/m&#xb7;24 h or less. The rate of change in dimension of the polarizer in the uniaxially stretched direction is &#xb1;0.1% or less after left at a temperature of 60&#xb0; C. and humidity of 95% for 100 hours.

Polarizing plate having polarizer sides covered with low moisture permeable layers with permeability different than protective films covering the polarizer surfaces

A polyvinyl alcohol-based polarizing film is provided, and the polarizing film has excellent surface smoothness while the light transmittance and the polarization degree are improved due to the high stretch ratio. The polarizing film is obtained from a polyvinyl alcohol film having a thickness ranging from 85 &#x3bc;m to 150 &#x3bc;m by dyeing the film with a dichroic substance and stretching it to 4-7 times its original length. The polarizing film has a light transmittance ranging from 35% to 50% and a polarization degree of at least 80%, and the surface roughness in a direction perpendicular to the stretching axis is at most 0.04 &#x3bc;m based on a centerline average roughness. A transparent protective layer or a transparent protective plate comprising the transparent protective layer is formed on at least one surface of the polarizing film in order to provide a polarizing plate. The transparent protective layer can be subject to a pre-treatment selected from a hard-coat treatment and an anti-glare treatment. Additional optical layers are laminated on the polarizing plate in order to provide an optical element. A polarizing plate or an optical element comprising the above-mentioned polarizing film has an excellent light transmittance and polarization degree, so that stripe-shaped streaks inhibiting visibility will not be observed substantially even in a reflection mode.

Polarizing plate, optical element, and liquid crystal display

A polarizing plate and a liquid crystal display using the same are disclosed. The polarizing plate includes a polarizer made of a synthetic resin and protective films. The same protective films are attached to both sides of the polarizer. When a FTIR-ATR method is carried out with respect to the both sides of the protective film and a peak intensity (A) in the wavelength range around 1488 cmof one side, a peak intensity (B) in the wavelength range around 1365 cmof one side, a peak intensity (A') in the wavelength range around 1488 cmof another side and a peak intensity (B&#x2032;) in the wavelength range around 1365 cmof another side are measured, and (C) and (C&#x2032;) are represented by the relationships: (A)/(B)=(C) and (A&#x2032;)/(B&#x2032;)=(C&#x2032;), (C)/(C&#x2032;)&#x2267;1.2 is satisfied. The same sides of the protective films having the (C) and (C&#x2032;) are adhered to both sides of the polarizer. In the polarizing plates, in accordance with the invention, even at the exposure to heat and humidity, advantageously occurrence of curling (warping) is reproduced.

Polarizing plate having protective films with plasticizer, liquid crystal display using the same, and methods of making the same

A polarizing plate having excellent moisture durability and a liquid crystal display using the same are disclosed. The polarizing plate is produced by covering all surfaces and sides of a polarizer with low moisture-permeable layers having moisture permeability of 310 g/m &middot;24 h or less. The rate of change in dimension of the polarizer in the uniaxially stretched direction is &plusmn;0.1% or less after left at a temperature of 60&deg; C. and humidity of 95% for 100 hours.

Growing community of inventors

Ibaraki, Japan

Eiji Hamamoto