| 摘要 |
<p>PURPOSE:To obtain the above vessel which has transparency and high crystallinity and to retain this transparency and heat resistance even in the heated atmosphere by melting and molding the copolymerized polyester resin having 0.7 or higher intrinsic viscosity and preparing a sheet and thereafter aging the sheet at the specified temp. and treating this sheet and then aging and molding it. CONSTITUTION:A sheet having low crystallinity, transparency and nonorientation properties is obtained by drying copolymerized polyester resin having 0.7 or higher intrinsic viscosity preferably for five hours or more and thereafter extruding it into a sheet shape by an extruder equipped with a T-die and quenching this sheet on a casting drum. At this time, a range of the preferable thickness of the sheet is regulated to 0.05-2.00mm more preferably to 0.10-1.00mm. After the sheet is extruded, it is aged at the temp. selected so that a formula I is obtained. Furthermore aging is performed so that the sheet after aging satisfies the conditions of a formula II to eliminate unevenness of wall thickness. At this time, the aging temp. is preferably regulated to >=30 deg.C. After aging, furthermore the sheet is molded into a vessel having a required shape by aging and forming such as vacuum forming and pressure forming, etc. The temp. range of a mold in a time of molding is regulated to a range shown in a formula III. The relative crystallinity(CR) of a transparent and high crystalline vessel after aging and molding is preferably regulated to >=50% or higher as CR. Further even when the obtained vessel is heat-treated at 120 deg.C, the haze value of this vessel holds 20% or below of the preferable specified value.</p> |
