A retardation film includes a polyester-series resin exhibiting a negative orientation birefringence and a forward wavelength dispersibility in retardation in combination with a polyamide-series resin exhibiting a positive orientation birefringence and a flat dispersibility in retardation. The polyester-series resin may contain a constitutional unit having a fluorene-9,9-diyl group, and the polyamide-series resin may contain a constitutional unit having an alicyclic skeleton. The polyester-series resin may contain at least one constitutional unit selected from a fluorenedicarboxylic acid unit (A1) containing a unit of the formula (1) and a fluorenediol unit (B1) containing a unit of the formula (2):

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wherein R.sup.1 and R.sup.2 each represent a substituent; k and m each denote an integer of 0 to 8; X.sup.1a, X.sup.1b, X.sup.2a, and X.sup.2b each represent a hydrocarbon group; A.sup.1a and A.sup.1b each represent an alkylene group; n1 and n2 each denote an integer of not less than 0. The retardation film has both a high retardation expression and a reciprocal wavelength dispersibility.

The present invention is directed to bifuran copolyesters comprising 2,2′-bifuran-5,5′-dicarboxylic monomer residues. The present invention is further directed to films, coatings or articles comprising said bifuran copolyesters. Also production methods for said bifuran copolyesters are provided. The invention is also directed to a use of a 2,2′-bifuran-5,5′-dicarboxylic monomers in preparing copolyesters having ultraviolet light (UV) blocking properties.

The present invention is directed to bifuran copolyesters comprising 2,2′-bifuran-5,5′-dicarboxylic monomer residues. The present invention is further directed to films, coatings or articles comprising said bifuran copolyesters. Also production methods for said bifuran copolyesters are provided. The invention is also directed to a use of a 2,2′-bifuran-5,5′-dicarboxylic monomers in preparing copolyesters having ultraviolet light (UV) blocking properties.

A polyarylate resin includes repeating units represented by formulas (1), (2), (3), and (4).

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A third percentage is greater than 0% and less than 50%. The third percentage is a percentage of the number of repeats of the repeating unit represented by formula (3) relative to the total of the number of repeats of the repeating unit represented by formula (1) and the number of repeats of the repeating unit represented by formula (3). A fourth percentage is at least 35% and less than 70%. The fourth percentage is a percentage of the number of repeats of the repeating unit represented by formula (4) relative to the total of the number of repeats of the repeating unit represented by formula (2) and the number of repeats of the repeating unit represented by formula (4).

A bio-based polycarbonate ester resin is environment friendly by not containing a bisphenol, and exhibits excellent heat resistance, transparency, strength, hardness, dimensional stability and chemical resistance. Thus, the bio-based polycarbonate ester resin is suitable for use in an eyeglass frame. In addition, various colors may be painted and coated on during post-processing, a separate additive is not required during a molding process, and processing is undergone at a temperature lower than that for conventional plastic materials for an eyeglass frame, and thus manufacturing costs may be reduced.

A bio-based polycarbonate ester resin is environment friendly by not containing a bisphenol, and exhibits excellent heat resistance, transparency, strength, hardness, dimensional stability and chemical resistance. Thus, the bio-based polycarbonate ester resin is suitable for use in an eyeglass frame. In addition, various colors may be painted and coated on during post-processing, a separate additive is not required during a molding process, and processing is undergone at a temperature lower than that for conventional plastic materials for an eyeglass frame, and thus manufacturing costs may be reduced.

Disclosed are biodegradable polyester polymers comprising lignin-containing segments and vegetable-oil based segments. Also disclosed herein are methods of making biodegradable polyester polymers and the articles made from these polymers.

Disclosed are biodegradable polyester polymers comprising lignin-containing segments and vegetable-oil based segments. Also disclosed herein are methods of making biodegradable polyester polymers and the articles made from these polymers.

A resin composition contains: a resin containing a constituent unit (A) represented by general formula (1); and a resin containing a constituent unit (B) represented by formula (2) and/or a constituent unit (C) represented by formula (3). (R.sub.1 represents a methyl group or an ethyl group, R.sub.2 and R.sub.3 represent a hydrogen atom or a methyl group, and n represents 0 or 1.) (R.sub.a and R.sub.b represent a hydrogen atom, etc., R.sub.h represents an aryl group of 6-20 carbons, X represents a single bond or a fluorene group, A and B represent an alkylene group of 1-4 carbons, m and n represent integers 0-6, and a and b represent integers 0-10.) (R.sub.c and R.sub.d represent a hydrogen atom, etc., Y represents a fluorene group, A and B represent an alkylene group of 1-4 carbons, p and q represent integers 0-4, and a and b represent integers 0-10.)

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The polyester sheet in accordance with an aspect of the present invention contains crystals of polyester which is a polycondensate of polyvalent carboxylic acid and polyalcohol. The polyester sheet contains nano-oriented crystals which contain crystals of polyester in each of which a polymer chain is highly oriented and each of which has a crystal size of 50 nm or less. A heatproof temperature of the polyester sheet is higher than a temperature that is lower than an equilibrium melting point of the polyester by 80° C., and a melting point of the polyester sheet is higher than a temperature that is lower than the equilibrium melting point of the polyester by 40° C.