Method of purifying bishydroxyalkyl terephthalate
AssigneesOrgano Corporation, Aies Co., Ltd.
InventorsYuji Asakawa, Shin Asano
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Abstract
A container made of, e.g., polyethylene terephthalate is pulverized and decomposed in the presence of a catalyst by the use of a solvent such as an alcohol or glycol to obtain crude bishydroxyalkyl terephthalate. This crude bishydroxyalkyl terephthalate is then purified by filtration, a treatment with activated carbon, and a treatment with ion-exchange resins. The bishydroxyalkyl terephthalate thus obtained is condensed to produce a container or the like made of polyethylene terephthalate.
Claims26
A purification method of bishydroxyalkyl terephthalate in which crude bishydroxyalkyl terephthalate is purified, by treating it with activated carbon and ion exchange resins.
A purification method of bishydroxyalkyl terephthalate, which comprises:
- a depolymerization step of subjecting polyalkylene terephthalate to ester depolymerization to produce crude bishydroxyalkyl terephthalate, and
- a purification step of filtering the obtained crude bishydroxyalkyl terephthalate to purify it, and
- returns solids separated by the filtration in the purification step to the depolymerization step.
Dependencies are inferred from the claim text.