Abstract: A liquid silicone resin composition as a gasket material comprising a base resin, a first crosslinking agent for causing a crosslinking reaction of the base resin, a silane coupling agent, a second crosslinking agent for forming a bond to the silane coupling agent, and a silica filler is used to form a gasket in a heat exchanger. Using this liquid silicone composition, the adhesiveness of the gasket can be enhanced while ensuring the sealing reliability of the gasket compared with conventional gaskets. Even when a resin which is difficult to adhere a silicon resin is used as a material of the tank body, the adhesive force of the gasket to the tank body can be sufficiently increased.

Abstract: A refrigerant transporting hose includes a tubular gas impermeable material layer on a base layer. The gas impermeable material layer is made of a base material composed of PVOH (polyvinyl alcohol), and nano-filler particles having plate shapes. The nano-filler particles are mixed in the base material so as to enhance the barrier properties against refrigerant gas of the gas impermeable material layer. For example, a ratio of the nano-filler to the base material, contained in the gas impermeable material layer, is higher than 0% and lower than 20% by weight.

Abstract: A butyl rubber composition, which comprises 100 parts by weight of butyl rubber and 30 to 150 parts be weight of carbon black having a CTAB specific surface area of 30 to 100 m2/g and preferably further contains 10 to 100 parts by weight of a flat filler having an average particle size of 1 to 40 &mgr;m and an aspect ratio of 5 or more and 0.05 to 5 parts by weight of a coupling agent of organometallic compound is provided. The butyl rubber composition can give vulcanization molded products capable of effectively sealing a carbon dioxide refrigerant without generation of blisters, etc. therein.

Abstract: A butyl rubber composition, which comprises 100 parts by weight of butyl rubber and 30 to 150 parts by weight of carbon black having a CTAB specific surface area of 30 to 100 m2/g and preferably further contains 10 to 100 parts by weight of a flat filler having an average particle size of 1 to 40 &mgr;m and an aspect ratio of 5 or more and 0.05 to 5 parts by weight of a coupling agent of organometallic compound is provided. The butyl rubber composition can give vulcanization molded products capable of effectively sealing a carbondioxide refrigerant without generation of blisters, etc therein.

Abstract: An ethylene-propylene copolymer rubber (EP rubber) composition is usable as a molded rubber product having freon-gas barrier properties. The EP rubber composition is an organic peroxide vulcanizable (crosslinkable) type having, as a base, a rubber polymer containing an EP rubber of an amount of at least 30 wt. % in the whole rubber polymer. In addition, the EP rubber has a Mooney viscosity (ML1+4, 100° C.) of about 50 or greater.

Abstract: A leakage restriction device for a refrigeration cycle of a vehicle air conditioner in which refrigerant flows has first and second rubber gaskets. The first and second gaskets are disposed between a pipe and a pipe joint of the refrigeration cycle for restricting refrigerant from leaking into atmospheric air. The first gasket is disposed on an atmospheric-air side and the second gasket is disposed on a refrigerant side between the pipe and the pipe joint. The first gasket has a gas permeability lower than that of the second gasket, and has a blistering-resistance which is inferior to that of the second gasket. As a result, refrigerant is restricted from leaking into atmospheric air, and a blister is restricted from being formed in the first and second gaskets even when a pressure of refrigerant is rapidly changed.