초록 ▼

The invention described herein provides a process for recycling a mixed polymer recycle stream containing polyester polymers, particularly polyethylene terephthalate (PET) typically in the form of carbonated soft drink or other containers. This novel process includes the steps of: (1) contacting the

The invention described herein provides a process for recycling a mixed polymer recycle stream containing polyester polymers, particularly polyethylene terephthalate (PET) typically in the form of carbonated soft drink or other containers. This novel process includes the steps of: (1) contacting the mixed polymer recycle stream with a solvent which selectively dissolves the PET. (2) separating the selective solvent containing PET from the residual mixed polymer, (3) cooling the selective solvent to precipitate the PET, and (4) removing the selective solvent from the precipitated PET. It is preferable that the mixed polymer recycle stream be prepared for recycling by conventional steps, such as water washing. In a preferred embodiment, the mixed polymer recycle stream is chemically washed subsequent to water washing and prior to contact with the selective solvent. The PET recovered is preferably combined with “virgin”PET and further processed to increase its molecular weight.

대표청구항 ▼

A process for recovering a polyester polymer from a mixed polymer recycle stream, while maintaining the polyester polymer in polymer form, comprising: contacting a mixed polymer recycle stream comprising at least 50 weight percent polyester polymer, lesser portions of other polymers, including one o

A process for recovering a polyester polymer from a mixed polymer recycle stream, while maintaining the polyester polymer in polymer form, comprising: contacting a mixed polymer recycle stream comprising at least 50 weight percent polyester polymer, lesser portions of other polymers, including one or more polyolefins, and impurities, with a chemical wash solvent that dissolves at least a portion of the impurities present in the mixed polymer recycle stream and substantially rejects dissolution of the polyester polymer present in the mixed polymer recycle stream, to form a chemical wash solution containing impurities dissolved in the chemical wash solvent, and a residual mixed polymer recycle stream; separating the chemical wash solution from the residual mixed polymer recycle stream; contacting, at an elevated temperature, the residual mixed polymer recycle stream with a selective solvent that selectively dissolves the polyester polymer and substantially rejects dissolution of any other polymer present in the mixed polymer recycle stream, to form a residual waste stream, a separate polyolefin phase, and a selective solvent solution comprising the polyester polymer dissolved in the selective solvent; separating the selective solvent solution from the separate polyolefin phase, and from the residual waste stream; and precipitating the polyester polymer from the selective solvent solution, to form a precipitated polyester polymer and a spent selective solvent solution; and separating the spent selective solvent from the precipitated polyester polymer, to obtain a recovered polyester polymer product having an intrinsic viscosity of from about 0.2 dl/g to about 0.8 dl/g.