Patent ID: 7662329

Claim:
A method for manufacturing a centrifugal casting die comprising the steps of: supplying a first liquid agent for forming a backup layer to be releasably bonded to an inner surface of a cylindrical die with a die body; rotating the die body so that the first liquid agent is uniformly spread over the entirety of the inner surface of the die body; curing the first liquid agent spread over the entirety of the inner surface of the die body to form the backup layer, the backup layer being formed of a thermosetting resin, which does not exhibit a rubber-like elasticity in a temperature range from room temperature to 150° C. and which has a heat-resistant temperature equal to a curable temperature or higher; supplying a second liquid agent for forming a top layer to be bonded with an inner surface of the backup layer; rotating the die body so that the second liquid agent is uniformly spread over the entirety of the inner surface of the backup layer; curing the second liquid agent spread over the entirety of the inner surface of the backup layer to form the top layer, the top layer holding a centrifugally cast material supplied to the inner surface thereof the centrifugally cast material being released from the inner surface of the top layer; and forming piled top layers by forming at least one fresh top layer on the inner surface of an existing top layer after repeating the step of releasing the centrifugally cast material from the inner surface of the fresh top layer, wherein the step of supplying a second liquid agent and forming the top layer comprises the step of further spraying a liquid containing a surface-roughing agent on the inner surface of the top layer which is still uncured at the time and before the second liquid agent spread over the entirety of the inner surface of the backup layer has completely cured to roughen the inner surface of the top layer, to easily release the cured cylindrical centrifugally cast material from the inner surface of the top layer.