| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to stabilize the degree of a pressure reduction with lapse of time, to shorten a molding time and to prevent contamination by a raw material by reducing the pressure over the entire part of a vacuum chamber in a centrifugal molding apparatus and pouring the raw material consisting of a varnish polymer into a hollow forming tube. SOLUTION: A rotating device is rotated in a reduced pressure atmosphere and is subjected to internal deposition under heating at the time of producing the preform for a GI-POF to be manufactured by internal deposition by using the varnish polymer 14 and keeping the polymer rotated within a rotating body consisting of a hollow tube 15. A chuck 6 holds the hollow tube 15 by coming into contact therewith at plural points. A draw part 17 for splashing the solvent of the varnish polymer 14 from the inside of the hollow tube is disposed at the center on the cap of the hollow tube 15. The vanish polymer 14 is one or >=2 kinds of a monomer having a polymerizable unsatd. bond, ring opening polymerizable monomer or a monomer having the group having atoms of silicon, fluorine, nitrogen, sulfur, etc., in the monomer, among which a fluorine-contained (meth)acrylic acid monomer is more preferable. |
