Abstract: An impeller for a water pump includes an impeller main body composed of a synthetic resin and having a vane member formed around a rotating center portion; and a metal boss in which a circular boss member positioned on the forward side of the rotating center portion and provided with a gradually narrowing portion at the axial end thereof, and a periaxial support boss member positioned on the rearward side of the rotating center portion are consecutively formed in the axial direction, and in which an axial support surface is formed between the circular boss member and periaxial support boss member, the metal boss being insert-fitted into said rotating center portion.

Abstract: A resinous hose formed by the process for producing a resinous hose, wherein the hose comprises cylindrical portions extending rectilinearly and a bent bellows portion wherein the bellows portion includes a bellows wall having continuous crests and valleys, and a non-bellows wall located on the side diametrically opposite to the bellows wall. The outside diameter of the valleys of the bellows wall is smaller than an outside diameter of the cylindrical portions, and an outside diameter of the non-bellows wall is larger than the outside diameter of the cylindrical portions.

Abstract: A material for liquid keeping containers comprising a resin composition which contains a syndiotactic polystyrene resin and a polypropylene resin and includes a compatibilized structure of the syndiotactic polystyrene resin phase and the polypropylene resin phase, the proportion of these phases being 90-10/10-90 (weight ratio).

Abstract: The present invention relates to a multi-layer hose for automobile cooling systems which comprises at least two layers of inner layer and outer layer wherein: (1) the material for inner layer is a composition which contains a polymer containing a carboxyl group and/or its derivative group in the molecule and a dynamically crosslinked olefin thermoplastic elastomer, the content of the polymer containing a carboxyl group and/or its derivative group thereof in the molecule being 5-50% by weight based on the total weight of the composition and (2) the material for outer layer comprises a polyamide thermoplastic resin.

Abstract: Bellows-shaped pleats are formed by a corrugator on bellows portions of a cylindrical hose formed by extrusion from a thermoplastic resin. The height of the pleats of the hose is uniform in a circumferential direction, and the numbers of the pleats on the bellows portions are different from one another. When water is encapsulated in the hose and the hose is heated, the pleats having different circumferential shapes from one another are stretched by the pressure of a vapor generated from the water, whereby the bellows portions of the hose are bent automatically with the portions corresponding to generating lines and free from the pleats being on an inner side. The bending angle at that time is determined depending on the numbers of the pleats. Thus, it is possible to provide a resinous hose at a low cost, which is formed, so that even if the hose is used in a high-temperature and a high-pressure environment, the bent shape of the hose can be maintained over a long period of time.

Abstract: An impeller for a water pump in which a metal boss is insert-fitted into the rotating center portion of the impeller main body, and the area of the rotating center portion facing the impeller main body is fashioned to an adequate thickness, with the metal boss securely fitting into the impeller main body.

Abstract: Bellows-shaped pleats are formed by a corrugator on bellows portions of a cylindrical hose formed by extrusion from a thermoplastic resin. The height of the pleats of the hose is uniform in a circumferential direction, and the numbers of the pleats on the bellows portions are different from one another. When water is encapsulated in the hose and the hose is heated, the pleats having different circumferential shapes from one another are stretched by the pressure of a vapor generated from the water, whereby the bellows portions of the hose are bent automatically with the portions corresponding to generating lines and free from the pleats being on an inner side. The bending angle at that time is determined depending on the numbers of the pleats. Thus, it is possible to provide a resinous hose at a low cost, which is formed, so that even if the hose is used in a high-temperature and a high-pressure environment, the bent shape of the hose can be maintained over a long period of time.

Abstract: A material for liquid keeping containers comprising a resin composition which contains a syndiotactic polystyrene resin and a polypropylene resin and includes a compatibilized structure of the syndiotactic polystyrene resin phase and the polypropylene resin phase, the proportion of these phases being 90-10/10-90 (weight ratio).

Abstract: The present invention relates to a multi-layer hose for automobile cooling systems which comprises at least two layers of inner layer and outer layer wherein: