Osaka Gas Chemicals Co., Ltd.

Yoshiya Ota

Shinichi Kamei

Shinsuke Miyauchi

Yasuhiro Suda

Shogo Suga

Nagayoshi Masuda

A retardation film includes a polyester-series resin exhibiting a negative orientation birefringence and a forward wavelength dispersibility in retardation in combination with a polyamide-series resin exhibiting a positive orientation birefringence and a flat dispersibility in retardation. The polyester-series resin may contain a constitutional unit having a fluorene-9,9-diyl group, and the polyamide-series resin may contain a constitutional unit having an alicyclic skeleton. The polyester-series resin may contain at least one constitutional unit selected from a fluorenedicarboxylic acid unit (A1) containing a unit of the formula (1) and a fluorenediol unit (B1) containing a unit of the formula (2): wherein Rand Reach represent a substituent; k and m each denote an integer of 0 to 8; X, X, X, and Xeach represent a hydrocarbon group; Aand Aeach represent an alkylene group; n1 and n2 each denote an integer of not less than 0. The retardation film has both a high retardation expression and a reciprocal wavelength dispersibility.

Retardation film and applications thereof

A retardation film comprising: a first resin layer comprising resin A having negative intrinsic birefringence, wherein in-plane phase difference Ro(450) at an angle of incidence of 0° for light at a wavelength of 450 nm, in-plane phase difference Ro(550) at an angle of incidence of 0° for light at a wavelength of 550 nm, and in-plane phase difference Ro(650) at an angle of incidence of 0° for light at a wavelength of 650 nm meet Ro(450)>Ro(550)>Ro(650); and a second resin layer comprising resin B having positive intrinsic birefringence, wherein in-plane phase difference Ro(450) at an angle of incidence of 0° for light at a wavelength of 450 nm, in-plane phase difference Ro(550) at an angle of incidence of 0° for light at a wavelength of 550 nm, and in-plane phase difference Ro(650) at an angle of incidence of 0° for light at a wavelength of 650 nm meet Ro(450)>Ro(550)>Ro(650), the retardation film having a Nz coefficient of −1.0 to 1.0, wherein in-plane phase difference Ro(450) at an angle of incidence of 0° for light at a wavelength of 450 nm, in-plane phase difference Ro(550) at an angle of incidence of 0° for light at a wavelength of 550 nm, and in-plane phase difference Ro(650) at an angle of incidence of 0° for light at a wavelength of 650 nm meet Ro(450)<Ro(550)<Ro(650).

Retardation film and method for producing same

Provided are a retardation film that has a high heat resistance, has excellent formability and handleability even in a single-layer structure, has a negative thickness-direction retardation Rth value, and is suitable as a negative A-plate or a positive C-plate and a method for producing the film. The retardation film is formed of a stretched film of a polyester resin, contains a unit (A1) represented by the formula (1) as a diol unit (A) and a unit (B1) represented by the formula (2a) or (2b) as a dicarboxylic acid unit (B), and is a negative A-plate or a positive C-plate. In the formulae, Zand Zrepresent an aromatic hydrocarbon ring, R, R, R, Rand Rrepresent a substituent, k, p1 and p2 denotes an integer of 0 to 8, q denotes an integer of 0 to 4, m1, m2, n1 and n2 denotes an integer of not less than 0, Aand Arepresents an alkylene group, and A, Aand Arepresents a divalent hydrocarbon group.

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Osaka, Japan

Yoshiya Ota