Abstract: Provided are a tape substrate having excellent oil resistance as well as balanced properties of flexibility, a hand cutting property and heat resistance, and an adhesive tape using the tape substrate. The tape substrate contains an ethylene-aromatic vinyl compound copolymer with an isotactic stereoregularity. Furthermore, the ethylene-aromatic vinyl compound copolymer is one having an alternating structure of ethylene and the aromatic vinyl compound represented by the formula (1) below, and an isotactic diad index m of Ph (an aromatic group) in the structure of the copolymer being more than 0.75: where Ph is an aromatic group and xa is the number of repeating units and an integer of at least 2.

Abstract: In consideration of that burning a PVC-based tape causes occurrence of dioxine, a nonhalogenated tape having physical properties and electric properties, which are comparable to a PVC-based tacking tape, and replaceable to the PVC-based tacking tape is desired. Simple replacement of PVC to a polyethylene-based synthetic resin causes a bad hand cutting performance. Hence, the composition of the synthetic resin composition is improved to have 100 weight parts of a polypropylene-based resin, 1 to 70 weight parts of a polyethylene-based resin, 1 to 200 weight parts of an inorganic filler with a range from 0.5 ?m to 10 ?m of an average grain size, and 0.1 to 50 weight parts of an compatibilizer to form a film. In addition, the film is drawn 1.05 to 3 times in an MD and thickness of the film is kept to 0.03 to 0.5 mm.

Abstract: In consideration of that burning a PVC-based tape causes occurrence of dioxine, a nonhalogenated tape having physical properties and electric properties, which are comparable to a PVC-based tacking tape, and replaceable to the PVC-based tacking tape is desired. Simple replacement of PVC to a polyethylene-based synthetic resin causes a bad hand cutting performance. Hence, the composition of the synthetic resin composition is improved to have 100 weight parts of a polypropylene based resin, 1 to 70 weight parts of a polyethylene-based resin, 1 to 200 weight parts of an inorganic filler with a range from 0.5 &mgr;m to 10 &mgr;m of an average grain size, and 0.1 to 50 weight parts of an compatibilizer to form a film. In addition, the film is drawn 1.05 to 3 times in an MD and thickness of the film is kept to 0.03 to 0.5 mm.

Abstract: A reciprocating actuator is axially connected to drive a reciprocating pump. An exhaust tube, open to the outside, passes through a piston of the reciprocating actuator and into an inner hole axially disposed in a working rod that connects an actuator piston of the reciprocating actuator to the reciprocating pump. A valve mechanism communicates a chamber above the actuator piston with the inner hole during upward motion of the piston, whereby actuator fluid above the piston is exhausted to the outside through the exhaust tube. The resulting axial exhausting of the actuating fluid permits inserting a large portion of the device into a drum for pumping of liquid. The invention permits use of a two-stage rod system, which is capable of obtaining high pumping pressure. The inner hole is communicated with a space whose volume changes when the working rod makes a vertical movement.

Abstract: An actuator is driven in a first direction by equal working fluid pressures acting on different piston areas acting in opposite directions, and is driven in a second direction by applying equal pressures on both sides of one of the piston areas. Working fluid from an inlet port, acting in a working fluid chamber, pushes up a valve plate, closes ventilation holes and opens working fluid discharge holes, thereby permitting the working fluid to push the piston upward. Working fluid contained in the working fluid chamber is exhausted from working fluid discharge holes to the outside of the system through a working fluid discharge pipe. When the upward movement of piston reaches its limit, a valve plate is pushed by a spring, thereby causing simultaneous closing of the working fluid discharge holes and the opening of the ventilation holes. As a result of the opened ventilation holes, working fluid pressures in a lower working fluid chamber and an upper working fluid chamber become equal.