| 摘要 |
<p>The invention relates to a method for increasing the molecular weight of polyesters by heating 100 parts of polyester with i) 0.01 to 5 parts of a tetracarbolic acid dianhydride, and ii) 0.01 to 5 parts of a copolymer comprising an epoxy group and based on styrene, acrylic acid ester, and/or methacrylic acid ester in an extruder to 160 to 350°C.</p> |
