A recycled poly(ethylene terephthalate) (rPET) blend processing method includes steps: adding a compatibilizer having a porous carbon structure to an rPET blend, wherein the rPET blend includes at least one of PET/PE blend plastic materials and PET/PP blend plastic materials; the porous carbon structure has a diameter ranging from 300 nm to 10 μm and a specific surface area of 300-1500 square meters per gram; mixing the compatibilizer and the rPET blend homogeneously to form a mixture; granulating the mixture to obtain mixture granules; and performing a pre-crystallization process and a solid-state polymerization process of the mixture granules, whereby to recycle and reuse the rPET hard to separate originally and reused, increase the crystallinity of the rPET, and raise the IV value to 0.6 and above.

The present disclosure provides a polyester and a molded article. The polyester includes residues of formula (i), formula (ii), formula (iii), and formula (iv):

##STR00001##

##STR00002##

##STR00003##

##STR00004##

in which R.sub.1 is an aromatic group, R.sub.2 is a C.sub.2-C.sub.6 straight-chain hydrocarbon group, * represents a linking bond. Based on 100 mol% of a sum of the residues of the formula (ii), the formula (iii) and the formula (iv), a content of the residue of the formula (iii) ranges from 50 mol% to 85 mol%, and the residue of the formula (iv) ranges from 12 mol% to 40 mol%.

The present disclosure provides a polyester and a molded article. The polyester includes residues of formula (i), formula (ii), formula (iii), and formula (iv):

##STR00001##

##STR00002##

##STR00003##

##STR00004##

in which R.sub.1 is an aromatic group, R.sub.2 is a C.sub.2-C.sub.6 straight-chain hydrocarbon group, * represents a linking bond. Based on 100 mol% of a sum of the residues of the formula (ii), the formula (iii) and the formula (iv), a content of the residue of the formula (iii) ranges from 50 mol% to 85 mol%, and the residue of the formula (iv) ranges from 12 mol% to 40 mol%.

The present invention relates to a polyester molded body and a method for manufacturing the same, the polyester molded body including polyester obtained by polymerization in the presence of an inorganic tin compound catalyst, wherein the polyester molded body containing an inorganic tin compound of the present invention may overcome problems caused by a residual antimony-based catalyst, and may be used as an eco-friendly container which does not affect taste and aroma when used as a food storage container due to reduced amounts of acetaldehyde and formaldehyde and which is not toxic to the human body.

The invention provides a liquid crystal polyester resin which not only has a low-dielectric tangent, but also is excellent in balance between heat resistance and processing stability. The liquid crystal polyester resin comprises: a structural unit (I) derived from an aromatic hydroxycarboxylic acid; a structural unit (II) derived from an aromatic diol compound; and a structural unit (III) derived from an aromatic dicarboxylic acid, wherein the structural unit (I) is a structural unit (IA) derived from 6-hydroxy-2-naphthoic acid, the structural unit (III) contains a structural unit (IIIA) derived from terephthalic acid, a structural unit (IIIB) derived from isophthalic acid, and a structural unit (IIIC) derived from 2,6-naphthalenedicarboxylic acid, the dielectric tangent at a measurement frequency of 10 GHz is 1.50×10.sup.−3 or less, the melting point is 290° C. or more, and the difference in temperature between the melting point and the crystallization point is 30° C. or more.

The present invention provides a polyester resin and a hollow molded body containing reduced amounts of cyclic trimer and aluminum-based foreign matter, with maintained catalytic activity and a reduced catalyst cost. A polyester resin, comprising an aluminum compound and a phosphorus compound, and satisfying the following (1) to (3): (1) a content of aluminum element in the polyester resin is 9 to 19 ppm by mass, (2) a content of phosphorus element in the polyester resin is 22 to 40 ppm by mass. and (3) a mole ratio of phosphorus element to aluminum element in the polyester resin is 1.55 or more and 1.85 or less.

The present invention provides a polyester resin and a hollow molded body containing reduced amounts of cyclic trimer and aluminum-based foreign matter, with maintained catalytic activity and a reduced catalyst cost. A polyester resin, comprising an aluminum compound and a phosphorus compound, and satisfying the following (1) to (3): (1) a content of aluminum element in the polyester resin is 9 to 19 ppm by mass, (2) a content of phosphorus element in the polyester resin is 22 to 40 ppm by mass. and (3) a mole ratio of phosphorus element to aluminum element in the polyester resin is 1.55 or more and 1.85 or less.

A process for producing a polyester having 2,5-furandicarboxylate units includes: a) providing or producing a starting composition including 2,5-furandicarboxylic acid, an aliphatic diol and a suppressant for suppressing ether formation between the aliphatic diol molecules, b) subjecting the starting composition to esterification conditions to produce an ester composition, and c) contacting the ester composition with a germanium containing catalyst at polycondensation conditions to produce a polyester including 2,5-furandicarboxylate units, where the suppressant includes amines and lithium hydroxide.

A process for producing a polyester having 2,5-furandicarboxylate units includes: a) providing or producing a starting composition including 2,5-furandicarboxylic acid, an aliphatic diol and a suppressant for suppressing ether formation between the aliphatic diol molecules, b) subjecting the starting composition to esterification conditions to produce an ester composition, and c) contacting the ester composition with a germanium containing catalyst at polycondensation conditions to produce a polyester including 2,5-furandicarboxylate units, where the suppressant includes amines and lithium hydroxide.

The present invention relates to a polyester container. The polyester container is formed from a polyester resin containing a particular content of diol moieties derived from isosorbide and diethylene glycol, and thus can show high transparency in spite of a great wall thickness thereof.