| 摘要 |
<p>A first layer raw material (21a) including a polymerizable compound and a polymerization initiator is supplied in a cylindrical first member (12). The first member is then rotated around the center of its circular cross section to polymerize the polymerizable compound, and a first layer (21) is formed. A reaction temperature TE1 (°C) in this polymerization step is determined to satisfy a formula expressed as TE2 - 20 = TE1 = TE2 + 25, wherein TE2 (°C) represents a 10-hour half-life temperature of the polymerization initiator. Thereafter, a second layer raw material (22a) is supplied in a hollow section of the first layer. The first member is then rotated to polymerize the polymerizable compound at the reaction temperature TE1, and a second layer (22) is formed. The supplying step and polymerization step are repeated alternately several times, and a second member (16) composed of plural layers is formed in the first member.</p> |
