| 摘要 |
PROBLEM TO BE SOLVED: To polymerize the core part of a preform while preventing the occurrence of air bubbles. SOLUTION: A clad pipe 12 with a length L of 60 cm is used and a polymerizable composition 58 for the core part is injected in the clad pipe 12. The clad pipe 12 is inserted in an autoclavce 41 and the atmosphere in the autoclave 41 is replaced with argon. Heaters 50-53 are used to adjust the temperatures of heights H1-H6 in an X-direction to 100, 98, 95, 93, 90 and 85°C. Since the advance of polymerization becomes faster in the lower part of the clad pipe 12 than that in the upper part thereof, the gas generated in the lower part is easily vented from the upper part held to a liquid state end air bubbles are not generated in the preform to which the core part is formed. COPYRIGHT: (C)2005,JPO&NCIPI |
