| 摘要 |
PURPOSE: To improve the melting stability and heat stability by using L- And/or D-lactide as a polymerization feedstock and compounding a crystallinzation nucleator therewith to effect melt polymerization and then cooling and solidifying the melt to effect solid-phase polymerization. CONSTITUTION: Component (A) comprisincy L-and/or D-lactide in an amount sufficient to provide a molar ratio of (0.1-0.01):1, 1% crystallization nucleator (B) which comprises fine inorganic particles of at least one compound selected from, e.g. an oxide, a carbonate, a sulfate, a hydroxide and a halide, having a primary particle size of at most 0.1μm and/or an organic component comprising a thermoplastic synthetic polymer having a softening point of at least 50 deg.C and disoersed to 0.1μm or smaller in a melt, component (C) comprising at least one compound selected from a polyalkylene glycol, a polyhydric alcohol and a cyclic lactone, and a lactide polymerization catalyst (D) comprising a tin compound are melted and kneaded at 180-220 deg.C in an inert atmosphere by using a twin-screw extruder to effect melt polymerization, and the melt is then cooled and solidified to effect solid-phase polymerization at 70-160 deg.C.
|
