| 摘要 |
PURPOSE:To obtain the titled fiber having an improved thermal resistance, a small transmission loss and a good mechanical strength by incorporating a polymer composed of methyl methacrylate and contg. more than a specific amount of a syndiotactic structure to a core component. CONSTITUTION:The polymer having a desired amount of the syndiotactic structure is prepared by carrying out the block or the solvent polymerization of the reaction components composed of a high purity methyl methacrylate, a high purity polymerization catalyst and a molecular weight modifier and also removing an impurity and a dust by a rectification. The polymerization temp. is selected to a temp. of less than 100 deg.C according to the amount of the syndiotactic structure contd. in the obtd. polymer. The core component comprises the polymer having >=50% the syndiotactic structure. While, the seath component comprises preferably a copolymer composed of 2,2,3,3,3-penta fluoropropyl methacrylate and methyl methacrylate, thereby obtaining the titled fiber having the prescribed properties. |
