Abstract: An optical recording medium protecting film which is a protecting film comprising a single transparent film made of a thermoplastic resin, having a retardation of no greater than 15 nm at a wavelength of 550 nm and a K value of no greater than 40 nm at 550 nm, having a glass transition temperature of 120° C. or higher and a water absorption of no greater than 1 wt %. |R(550)|?15 nm??(1) |K(550)|?40 nm??(2) (the K value being calculated by K=[nz?(nx+ny)/2]×d {where nx, ny and nz are the three-dimensional refractive indexes of the transparent film in the x-axis, y-axis and z-axis directions, respectively, and d is the thickness of the transparent film}). Also, an optical recording medium having a data recording layer and the above-mentioned protecting film on a substrate, wherein light is incident from the protecting film side.

Abstract: The present invention relates to a sheet material for forming a dielectric for a plasma display panel capable of forming a dielectric layer having a high withstand voltage, a smooth surface, and excellent transparency, and a process for producing same. Furthermore, the present invention also relates to a process for producing a dielectric layer constituting a plasma display panel. The sheet material for forming a dielectric for a plasma display panel of the present invention is a freestanding porous sheet material formed from an inorganic dielectric powder and a thermoplastic resin and having a thickness of 350 &mgr;m or less, and contains, as percentages by weight based on the total amount of the dielectric powder and the thermoplastic resin, the dielectric powder at 40% to 98% and the thermoplastic resin at 2% to 60%.

Abstract: In the present invention, a retardation film is produced by adjusting the mixing ratio of at least two kinds of mutually compatible polymers A and B and by forming the resulting mixture into the film. The polymers A and B are copolymers comprising respective two common repeating units and different in copolymerization composition. According to the present invention, the retardation film having the desired wavelength dispersion can industrially and simply be produced. Furthermore, there can be provided the high-quality retardation film capable of controlling the wavelength dispersion of the retardation at a high level.

Abstract: A retardation film that can compensate for the optical properties of the liquid crystal cells of a liquid crystal display device and thereby enhance image quality. The retardation film consists of a single polymer film, which has a wavelength range in which the retardation value is positive and a wavelength range in which it is negative in a wavelength range of 400-800 nm, and which satisfies the following inequality (1) and/or (2) and has a water absorption of no greater than 1% by mass.

Abstract: A film which is a single polymer film and has a smaller phase difference as the wavelength becomes shorter.

Abstract: A retardation film comprised of a single oriented polymer film, characterized in that the retardation at wavelengths of 450 nm and 550 nm satisfies the following formulae (1) and/or (2), and the water absorption is no greater than 1%. R(450)/R(550)<1  (1) K(450)/K(550)<1  (2) where R(450) and R(550) represent the in-plane retardation of the oriented polymer film at wavelengths of 450 nm and 550 nm, respectively, and K(450) and K(550) are the values calculated by K=[nz−(nx+ny)/2]×d (where nx, ny and nz represent the three-dimensional refractive indexes of the oriented polymer film as the refractive indexes in the direction of the x-axis, y-axis and z-axis, respectively, and d represents the thickness of the film) for the oriented polymer film at a wavelength of 450 nm and 550 nm, respectively. There are provided laminated retardation films and liquid crystal display devices employing the retardation film.

Abstract: In the present invention, a retardation film is produced by adjusting the mixing ratio of at least two kinds of mutually compatible polymers A and B and by forming the resulting mixture into the film. The polymers A and B are copolymers comprising respective two common repeating units and different in copolymerization composition. According to the present invention, the retardation film having the desired wavelength dispersion can industrially and simply be produced. Furthermore, there can be provided the high-quality retardation film capable of controlling the wavelength dispersion of the retardation at a high level.

Abstract: The present invention relates to a liquid crystal display element having improved utilization efficiency of light and a light source device constituting the liquid crystal display element, and said liquid crystal display element includes (I) a light source device comprising the following (i) to (iii): (i) a light guide body comprising a transparent medium, and having an end face through which the light emitted from a light source is introduced, a pair of opposing faces one of which works as a light emission face and a haze anisotropic layer, (ii) a light source placed at the end face of said light guide body, and (iii) a reflecting body placed at the opposite side to the light emission face side of said light guide body, and mainly emitting linearly polarized light of one vibration direction, and (II) a polarizing plate placed at the emission face side of the above-mentioned light guide body in such a manner that the polarization axis is parallel to the direction having the largest haze value in the abov

Abstract: An optical recording medium protecting film which is a protecting film comprising a single transparent film made of a thermoplastic resin, having a retardation of no greater than 15 nm at a wavelength of 550 nm and a K value of no greater than 40 nm at 550 nm, having a glass transition temperature of 120° C. or higher and a water absorption of no greater than 1 wt %.

Abstract: The waterstop used to prevent passage or leakage of water through a construction joint of concrete is shaped of a plastic or rubber in the form of a continuous-length belt-like form and provided with a water-swellable rubbery layer on at least a portion, or, for example, along the peripheries of the belt-like form, side-by-side coming into contact with the concrete bodies to serve as a water-tight filling of the joint by being swollen with water. The water-swellable rubbery layer is protected temporarily prior to use with a coating film of an alkali-soluble polymeric material which can at least partially be dissolved away by the alkalinity of the water in the concrete joint. The peripheries of the plastic- or rubber-made belt-like form are preferably in a length-wise bulged form having a bore running therethrough to serve as a stress absorber when the water-swellable rubbery layer is swollen with water.

Abstract: A fluorescent spectral analysis apparatus comprises a source of a laser beam, and first and second optical fibers to be inserted in an endoscope with forward ends extended from a distal end of the endoscope. The first optical fiber guides the laser beam emitted from the source to a subject portion to be analyzed and the second optical fiber transmits a fluorescent light generated from the subject portion due to irradiation with the laser beam. The fluorescent light is detected by a light-receiving element. The time interval between the instant of reception of the fluorescent light by the light receiver and the instant of generation of the laser beam from the source is measured.