| 摘要 |
PURPOSE:To form continuously a preform rod which can maintain high accuracy in shaping by extruding a photocurable compsn. having a specific compsn. ratio of a noncrystalline polymer, photopolymerizable monomer and photopolymn. initiator from a nozzle then irradiating active light to the extruded compsn. thereby photocuring the same. CONSTITUTION:A photocurable compsn. is constituted of a polymer, photopolymerizable monomer and photopolymn. initiator by adding 0.02-5pts.wt. photopolymn. initiator to 100pts.wt. compsn. prepd. by mixing the polymer and the monomer in a range of 80-20pts.wt. former and 20-80pts.wt. latter. If the content of the polymer included in 100pts.wt. compsn. combined with the polymer and the monomer exceeds 80pts.wt., the viscosity increases and on the other hand, when the content falls below 20pts.wt., the viscosity decreases too much in the stage of extruding the photocurable compsn. from an orifice and the fluctuation in the outside diameter of a preform increases. If the amt. of the photopolymn. initiator is below 0.02pt.wt., the photocuring speed decreases considerably and when said amt. exceeds 5pts.wt., the preform rod is colored and the phototransmittability is decreased. |
