Abstract: A polylactic acid composition comprising (A) a polylactic acid-series resin and (B) an acrylic triblock copolymer is prepared. The composition fulfills the following requirements: (1) the acrylic triblock copolymer (B) is a triblock polymer comprising (B1) a polymer block having a glass-transition temperature of not higher than 25° C., (B2a) a polymer block which has a glass-transition temperature of not lower than 60° C. and is bound to a terminal of the polymer block (B1), and (B2b) a polymer block which has a glass-transition temperature of not lower than 60° C. and is bound to another terminal thereof; (2) the polymer block (B1) comprises a main structural unit derived from an acrylate, and the polymer block (B2a) and the polymer block (B2b) independently comprise a main structural unit derived from a methacrylate; and (3) both of the weight-average molecular weights of the polymer block (B2a) and polymer block (B2b) are smaller than the weight-average molecular weight of the polymer block (B1).

Abstract: The present invention is a waterproof sheet for a tunnel containing a base sheet containing a synthetic resin having on a surface thereof a silica-containing surface layer containing silica having a silicon dioxide content of 90% by mass or more in a ratio of from 30 to 200 mg/cm3, formed over a depth of from 5 to 30 ?m from the surface of the waterproof sheet, and having a tensile breaking strength of 10 MPa or more and a mortar adhesion strength of 15 N/cm or more, and thus provides a waterproof sheet for a tunnel that forms no gap between the sheet and the concrete structure even when a prolonged period of time is elapsed from the installation, or the installed surface suffers large deterioration in evenness or levelness, ground subsidence or earthquake, and also does not cause problems including breakage and the like upon installation and after installation in the tunnel, thereby preventing smoothly water seeping from the earth or the ground from leaking into the tunnel.

Abstract: A polylactic acid composition comprising (A) a polylactic acid-series resin and (B) an acrylic triblock copolymer is prepared. The composition fulfills the following requirements: (1) the acrylic triblock copolymer (B) is a triblock polymer comprising (B1) a polymer block having a glass-transition temperature of not higher than 25° C., (B2a) a polymer block which has a glass-transition temperature of not lower than 60° C. and is bound to a terminal of the polymer block (B1), and (B2b) a polymer block which has a glass-transition temperature of not lower than 60° C. and is bound to another terminal thereof; (2) the polymer block (B1) comprises a main structural unit derived from an acrylate, and the polymer block (B2a) and the polymer block (B2b) independently comprise a main structural unit derived from a methacrylate; and (3) both of the weight-average molecular weights of the polymer block (B2a) and polymer block (B2b) are smaller than the weight-average molecular weight of the polymer block (B1).

Abstract: A blanket substrate comprising spun yarn of polyvinyl alcohol based fibers, in which the fibers have primary ridged streaks which are formed on their surfaces in the direction of the fiber axis with finer secondary ridged steaks formed in the primary ridged streaks, the fibers having a cross-section circularity of at least 80%.

Abstract: A blanket substrate comprising spun yarn of polyvinyl alcohol based fibers, in which the fibers have primary ridged streaks which are formed on their surfaces in the direction of the fiber axis with finer secondary ridged steaks formed in the primary ridged streaks, the fibers having a cross-section circularity of at least 80%.

Abstract: Polyvinyl alcohol based fibers having good fatigue resistance, dipped cords comprising the polyvinyl alcohol based fibers and having good fatigue resistance, and a method for producing the dipped cords. The polyvinyl alcohol based fibers have a tan&dgr; at 90° C. of at least 0.12, substantially one peak of tan&dgr; within a temperature range of from 60 to 120° C., and an elongation at break of at least 12%.

Abstract: A flat panel display device comprises an anode electrode, a fluorescent layer formed on the anode electrode, a cathode electrode having a plurality of cold cathodes, a gate electrode spaced from and electrically insulated from the cathode electrode for triggering emission of electrons by the cold cathodes, and a light-reflecting layer formed on or above the gate electrode face to face with the fluorescent layer.

Abstract: An electron tube is constructed to seal in vacuum a substrate for supporting an electron collect electrode, a substrate for supporting a cold cathode array, and a part of an electrode structure. Electrons, emitted from an electron discharge area composed of the cold cathode array and the electrode for picking up an electron beam, pass through a vacuum area and reach an electron collect electrode. The vacuum area is formed by anode jointing the outer peripheral portion of the substrate 1 for supporting the electron collect electrode with the part of the electrode for picking up an electron beam in a vacuum bath. After sealing them in vacuum, the vacuum level of the vacuum area can be kept unchanged when the electron tube is taken out of the vacuum vessel.

Abstract: A magneto-optic memory medium of an exchange-coupled ferrimagnetic double-layered structure having a recording film of a specific amorphous GdTbFe alloy and a reading film of a specific amorphous GdNdFe alloy.

Abstract: An opto-magnetic recording medium having a perpendicularly magnetized film of a dual layer structure comprising a first layer composed of a rare earth-transition metal amorphous thin alloy film and a second layer composed of a rare earth-transition metal amorphous thin alloy film of a composition different from that of the first layer and having a lower curie point and a larger coercive force as compared with that of said first layer, and being capable of transferring bits recorded at a curie point in said second layer to the first layer by exchange-coupling force, said first layer being composed of a GdDyFeCo film in which the sublattice magnetization for transition metal is predominant at a room temperature, the second layer being composed of TbFeCo series film in which sublattice magnetization for rare earth is predominant at a room temperature, and the directions of predominant magnetization between the first layer and the second layer being opposed to each other.