METHOD FOR PRODUCING RECYCLED POLYESTER CHIPS FROM RECYCLED POLYESTER FABRIC

• Main Authors: TSENG YU-TI, CHUANG JUNG-JEN, LIAO TEAO, HUANG ZHANG-JIAN
• Format: Patent
• Language: English; Japanese
• Published: 24.03.2023
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

To solve the problem in which: the conventional chemical recycling method involves a very low recovery rate of the BHET and complicated purification procedures, causing a high material recovery cost.SOLUTION: A method for producing recycled polyester chips from a recycled polyester fabric is provided. The method includes the steps of: providing a polyester fabric attached with a dye and/or coating glue; performing a color removal process to at least partially remove the dye and/or coating glue attached to the polyester fabric; and performing a de-polymerization process including: using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing bis(2-hydroxyethyl) terephthalate (BHET) and oligomers; performing a purification process so as to enhance a purity of the BHET in the de-polymerization product; and performing a granulation process so as to re-polymerize the purified BHET and form the recycled polyester chips (r-PET).SELECTED DRAWING: Figure 1 【課題】従来のケミカルリサイクル法では、ＢＨＥＴの回収率が非常に低く、精製方法が複雑であるため、材料の回収コストが高い。【解決手段】ポリエステル織物から再生ポリエステルチップを製造する方法は、染料および／またはコーティンググルーが付着したポリエステル織物を提供するステップと、ポリエステル織物に付着した染料および／またはコーティンググルーを少なくとも部分的に除去する脱色操作を行うステップと、以下を含む解重合操作を行うステップとを含む。化学的解重合液を用いてポリエステル織物を化学的に解重合し、ビス（２－ヒドロキシエチル）テレフタレート（ＢＨＥＴ）とオリゴマーを含む解重合物を形成するステップと、解重合物におけるＢＨＥＴの純度を向上させる精製操作と、精製されたＢＨＥＴを再重合させて再生ポリエステルチップ（ｒ－ＰＥＴ）を形成する造粒操作とを含む。【選択図】図１