Abstract: For simply and surely manufacturing a double wall corrugated pipe having a socked part of a predetermined shape without any deformation, in a method for manufacturing a double wall corrugated pipe 1 having a slot part 3 on one end and a socket part 2a on the other hand, an external wall 11 (21, 31) of a continuous irregular circular shape, and an inner wall 12 (22) of a cylindrical shape by subjecting a thermoplastic resin to extrusion molding, before the double wall corrugated pipe 1 to be extrusion-molded is cooled off, a pore is formed in an external wall 21 portion of the socket part 2a by piercing with a needle 5 to allow a hollow chamber 23 of the socket part 2a to communicate with the air, so as to be designed to surely prevent shrinkage or deformation of an external wall 21 of the socket part 2b accompanied by a decrease in temperature.

Abstract: For simply and surely manufacturing a double wall corrugated pipe, there is provided a method for manufacturing a double wall corrugated pipe having a slot part 3 on one end, a socket part 2b on the other end, an external wall 6 of a continuous irregular shape, and an inner wall 7 of a tubular shape by subjecting a thermoplastic resin to extrusion molding, comprising at least: a first cutting step in which a double-wall continuous tubular body 1a to be extrusion molded in a state of which the socket part 2b (2a) and the slot part are being coupled together is cut off at an external wall part X corresponding to the end portion of the socket part 2b and at an external wall part Y corresponding to the end of the slot part 3; and a second cutting step in which a cutting unit is inserted to a predetermined position from a socket part 2a side opening to an internal cavity portion 9 of the double wall single tubular body 1b obtained in the first cutting step, and the inner wall 7 is cut off in a circumferential dire

Abstract: An acrylic rubber composition comprising (A) 100 parts by weight of an acrylic rubber comprising (a) 90 to 99.9% by weight of acrylic acid ester monomer units, (b) 0.1 to 10% by weight of carboxyl group-containing ethylenically unsaturated monomer units, and (c) 0 to 20% by weight of other copolymerizable monomer units, (B) 0.05 to 2.5 parts by weight of a primary monoamine compound, and (C) 0.05 to 5 parts by weight of a polyamine vulcanizer. The rubber composition gives a vulcanizate which is used as sealing material, hose material, vibration insulator material, tube material, belt material and boot material.

Abstract: An acrylic rubber composition comprising 100 parts by weight of (a) an acrylic rubber having carboxyl groups, 0.3 to 8 parts by weight of (b) an aromatic secondary amine compound, and 0.3 to 8 parts by weight of (c) nickel dialkyldithiocarbamate. A crosslinkable acrylic rubber composition further comprising 0.1 to 10 parts by weight of a crosslinking agent in addition the ingredients (a), (b) and (c). By crosslinking the crosslinkable acrylic rubber composition, a crosslinked article having high heat resistance and exhibiting especially a reduced variation in elongation by heat load can be obtained.

Abstract: An acrylic rubber composition comprising 100 parts by weight of (a) an acrylic rubber having carboxyl groups, 0.3 to 8 parts by weight of (b) an aromatic secondary amine compound, and 0.3 to 8 parts by weight of (c) nickel dialkyldithiocarbamate. A crosslinkable acrylic rubber composition further comprising 0.1 to 10 parts by weight of a crosslinking agent in addition the ingredients (a), (b) and (c). By crosslinking the crosslinkable acrylic rubber composition, a crosslinked article having high heat resistance and exhibiting especially a reduced variation in elongation by heat load can be obtained.