Nitto-denko Corporation

Miyuki Kurogi

Yutaka Ohmori

Toshiyuki Iida

Tomoyuki Hirayama

Hisae Shimizu

Junichi Nagase

Takahisa Konishi

Satoru Suzuki

Hisae Sugihara

Sadahiro Nakanishi

The present invention provides a polarizing film having a high dichroic ratio. The polarizing film contains a disazo compound represented by the following general formula (1). In the general formula (1), Qrepresents a phenyl group having at least one &#x2014;SOM group; Qrepresents a naphthylene group having at least one &#x2014;SOM group; X represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a thioalkyl group having 1 to 4 carbon atoms, a halogeno group, or a polar group; subscript k denotes the number of substitutions of X and represents an integer of 0 to 5; and M represents a counter ion, where when k is an integer of 2 or more, Xs are the same or different. 

Polarizing film, image display device, and method for producing polarizing film

The retardation film of the present invention contains a thermoplastic polymer having at least a side chain component (A) oriented in a direction substantially orthogonal to a slow axis, and the absorption edge wavelength (&#x3bb;) of the side chain component (A) is 330 nm or more, and an in-plane retardation value (Re[450]) at a wavelength of 450 nm is smaller than that (Re[650]) at a wavelength of 650 nm. In the above-mentioned retardation film, the difference (&#x394;Re=Re[650]&#x2212;Re[450]) between the in-plane retardation value (Re[650]) at a wavelength of 650 nm and the in-plane retardation value (Re[450]) at a wavelength of 450 nm is preferably 10 nm or more. The retardation film of the present invention exhibits optical characteristics in which the in-plane birefringence is large and the difference between a retardation value on the short wavelength side and a retardation value on the long wavelength side is large.

Retardation film, optical laminated body, liquid crystal panel, and liquid crystal display

The birefringent film of the present invention contains an aromatic polyester having a repeating unit represented by the following general formula (1). In the general formula (1), A(s), B(s), C(s), and D(s) are each independently represent a group selected from a halogeno group, an alkyl group which has 1 to 6 carbon atoms, and an aryl group. Also, a and b each represent an integer of 0 to 4, and c and d each represent an integer of 0 to 3. R1 represents a hydrogen atom, or an alkyl group which has 1 to 10 carbon atoms. R2 represents an alkyl group which has 2 to 10 carbon atoms. R3 to R6 each independently represent a group or atom selected from a hydrogen atom, a halogeno group, an alkyl group which has 1 to 6 carbon atoms, and an aryl group. Furthermore, l and m each represent an integer of 2 or more. 

Birefringent film, polarizing plate, image display, and aromatic polyester

The present invention provides an optical film exhibiting wavelength dispersion such that a retardation value is smaller on the shorter wavelength side, and capable of being also formed comparatively thinly. The optical film of the present invention is an optical film including a polyimide-based polymer represented by the following general formula (I). In the formula (I), m is 40% by mol or more and 100% by mol or less. Rand Reach independently denote a substituent having a carbon-carbon double bond or a triple bond. A, A', B, B&#x2032;, E, G, and H each denote a substituent, and small letters corresponding to these alphabets denote substitution number thereof. X and Y each independently denote bond part such as a covalent bond. The substituents having a carbon-carbon double bond or a triple bond represented by Rand Rare a substituted or unsubstituted aryl group, a substituted or unsubstituted vinyl group, and a substituted or unsubstituted ethynyl group. 

Optical film and image display device

[Object] The present invention provides a liquid crystal panel with which a display with extremely small change in color depending on a viewing direction can be realized, and a liquid crystal display including the same. [Solution to Problem] The liquid crystal panel includes: a first polarizer; a second polarizer; a first optical compensation layer; a second optical compensation layer; and a liquid crystal cell. The first polarizeris arranged on one surface of the liquid crystal cell. The second polarizeris arranged on the other surface of the liquid crystal cell. The first optical compensation layeris arranged between the liquid crystal celland the first polarizer. The second optical compensation layeris arranged between the liquid crystal celland the second polarizer. The first optical compensation layersatisfies the following mathematical formulae (1) and (2). The second optical compensation layer satisfies the following mathematical formulae (3) and (4).&#x2003;&#x2003;(1)([450]/[550])&#x3c;1.00&#x2003;&#x2003;(2)&#x2003;&#x2003;(3)([450]/[550])&#x2267;1.10&#x2003;&#x2003;(4)

Liquid crystal panel and liquid crystal display

An ester-based polymer to be used in the present invention has at least a repeating unit represented with the general formula (I). A and B are substituents substituted on a stilbene group. Ris a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group. Ris a linear or branched alkyl group having 2 to 10 carbon atoms. Rto Reach independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group. n is an integer of 2 or more. 

Birefringent film and polarizer

The invention relates to an optical film containing polymers having different repeating units, and methods for production thereof. Further, the invention also relates to an optical laminate, a polarizing plate, and an image display device each using the optical film. The optical film of the invention advantageously has not only high solubility in solvents but also a high level of transparency since the polymers used in the optical film are compatible with each other. Further, wavelength dispersion of the birefringence of the optical film can be controlled by merely changing a ratio of polymers.

Optical film and method for production thereof

An object of the present invention is to provide an optical film exhibiting a preferable wavelength dispersion and capable of being formed comparatively thinly. The present invention is an optical film containing the repeating unit represented by the following general formula (II). In the formula (II), A, A', B, and B&#x2032; each denote a substituent, a, a&#x2032;, b, and b&#x2032; denote the number of substituents of the corresponding A, A&#x2032;, B, and B&#x2032;. A, A&#x2032;, B and B&#x2032; each independently denote a halogen or an alkyl group having 1 to 4 carbon atoms. Rand Rdenote a halogen, an alkyl group having 1 to 10 carbon atoms, and the like. X denotes &#x2014;CO&#x2014;, &#x2014;SO&#x2014;, and the like. 

Optical film, image display device, diethynylfluorene, and polymer thereof

An optical film of the present invention comprises a polyimide-based polymer represented by the following general formula (V).  The optical film of the present invention exhibits an optical property such that wavelength dispersion of retardation scarcely changes ranging from the short wavelength side to the long wavelength side. Typically, the optical film of the present invention may be used as a retardation film of a liquid crystal display device.

The invention relates to an optical film containing aromatic polymer which shows high solubility to solvents, and methods for production thereof. Further, the invention also relates to an optical laminate, a polarizing plate, and an image display device each using the optical film. The optical film may be attained by using polyester with a specific structure. The polyester with a specific structure may be obtained by condensation polymerization of bisphenol compound(s) and dicarboxylic acid compound(s) with biphenyl structure, and preferably has no halogen atom in its chemical structure. The optical film of the invention advantageously has not only high solubility in solvents but also a high level of heat resistance and birefringence producing capability. When the content of the biphenyl structure is high, the optical film of the invention can also have large wavelength dispersion of birefringence.

An optical film containing a polymer having at least a repeating unit represented by following general formula (I): The optical film is excellent in heat resistance, transparency and processability because it contains a polymer having a naphthyl group in a molecular structure. In addition, when a retardation film is produced by drawing the optical film, a composition ratio of the polymer can be adjusted in a specific range so that the retardation film exhibits inverse wavelength dispersion properties such that higher retardation value is offered in measuring by light with longer wavelength. The retardation film having such properties is extremely useful for improving display properties of a liquid crystal display device. The optical film is also used in the production of a polarizing plate.

Growing community of inventors

Ibaraki, Japan

Miyuki Kurogi