Orientated carbon nanotube composite, process for producing orientated carbon nanotube, and, produced using orientated carbon nanotube composite, pneumatic tire, wheel for vehicle, tire wheel assembly and disk brake

Abstract

A carbon nanotube orientated composite formed by orientating carbon nanotubes in a given direction in a matrix having a heat conductivity lower than that of carbon nanotube, in which at least a part of carbon nanotubes are contacted with each other to be continuous from one end to the other end between both ends in the orientated direction, is provided as a material having a heat conductivity considerably higher than that of copper, aluminum or the like or a material to be disposed in rubber material having a low heat releasing characteristic to considerably improve the heat conduction, and also there are provided a method of producing the same as well as a pneumatic tire, a wheel for a vehicle, a tire-wheel assembly and a disc brake using this material.

Description

TECHNICAL FIELD [0001] This invention relates to a carbon nanotube orientated composite formed by orientating carbon nanotubes in a matrix and a method of producing the same as well as a pneumatic tire, a wheel for a vehicle, a tire-wheel assembly and a disc brake having a heat dissipation improved by using the carbon nanotube orientated composite. BACKGROUND ART [0002] As a general-purpose heat conductive material for thermal machine accompanied with a phenomenon of heat exchange and heat conduction, or for heat dispersion have hitherto been used a cast iron, stainless steel, copper and copper alloy, aluminum and aluminum alloy, nickel and nickel alloy, titanium and titanium alloy, zirconium alloy and the like. Particularly, copper, aluminum and the like having a highest heat conductivity over a temperature range from room temperature to higher temperature are used in thermal machines requiring a high heat conductivity such as heat exchangers and the like. [0003] However, thermal m...

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Benefits of technology

[0008] The carbon nanotube is a structural body made of carbon atom having a diameter of about few nm to few hundreds nm and has an extremely fine tubular structure of an order corresponding to 10−3 times of usual carbon fiber (CF)(average diameter: not less than 5 μm, length: about 100 μm). Although the heat conductivity of the carbon nanotube itself is not clear because the measuring method is not established, it is theoretically guessed from the crystal structure that the heat conductivity is very high. In the carbon nanotube orientated composite according to the invention, the carbon nanotubes orientated in the matrix are contacted with each other and connected from one end to the other end between both the ends in the orientated direction to form a carbon nanotube continuous body, so that when the carbon nanotube orientated composite is arranged in a part to be heat-released so as to locate one end of the continuous body at a high temperature side and the other end thereof at a low temperature side, the heat releasing characteristics of this part can be improved.

[0058] According to this invention, the carbon nanotube orientated composite is extended from the sliding surface or the vicinity thereof to the surface as a heat releasing surface other than the sliding surface, so that heat generated at the sliding surface can be transmitted through the carbon nanotube orientated composite and rapidly released from the heat releasing surface and hence the disc brake having a higher heat releasing performance can be constructed. Moreover, the feature that one end of the carbon nanotube orientated composite is terminated in the vicinity of the sliding surface means that the end is terminated at a position shallowest from the sliding surface in a depth direction within a range that the end is not exposed to the sliding surface even if the sliding surface is worn.

Problems solved by technology

However, in order to obtain a satisfactory effect, it is required to fairly increase the compounding amount of the filler or the like, and as a result, there are caused problems that the dispersion of the filler becomes non-uniform and dynamic properties are lowered.

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