To provide a vapor chamber in which a hydraulic fluid composed of a nonfreezable additive for controlling formation of water and crystal of ice is used.
A heat conduction element comprises the vapor chamber which has an evaporation part and a condensation part and is closed in vacuum and a hydraulic fluid which is sealed in the vapor chamber and is composed of water and the nonfreezable additive in an effective amount to kinetically control formation of nucleus of ice and growth of crystal of ice in the hydraulic fluid when a temperature is below 0°C. The heat conduction element comprises the nonfreezable additive substantially consisting of a water-soluble polymer. The heat conduction element comprises the water-soluble polymer in an amount of about 0.01 to about 1.5 wt.% based on the total of a liquid.
NODA HAJIME
NIEKAWA JUN
