The embodiments relate to a polyester film, which comprises a copolymerized polyester resin comprising a diol component and a dicarboxylic acid component and has a heat shrinkage rate of 30% or more in the main shrinkage direction upon thermal treatment at a temperature of 80° C. for 10 seconds and a melting point of 170° C. or higher as measured by differential scanning calorimetry, which not only solve the environmental problems by improving the recyclability of the polyester container, but also are capable of enhancing the yield and productivity, and a process for regenerating a polyester container using the same.

The polyester film according to the embodiment prepared while the crystallinity of a copolymerized polyester film is controlled can be improved in thermal properties and chemical properties. Specifically, the polyester film has not only an excellent shrinkage rate with respect to temperature, but also excellent adhesive strength by a solvent even when applied to gravure printing, UV curing printing, and VSOP printing, making it suitable for a heat shrinkage process and a seaming process. In addition, the polyester film can be applied to a recycling process since it has an appropriate change in crystals during washing with an aqueous solution of NaOH, and the generation of fusion is suppressed even upon prolonged high-temperature drying.

An opacified polymeric composition including a first polymer having a first refractive index; a second polymer having a second refractive index, wherein the second refractive index of the second polymer is lower than the first refractive index of the first polymer; a light scattering inorganic additive; a light absorbing additive; and a light reflecting additive.

Provided is a method for manufacturing an LCP film for a circuit substrate capable of achieving an LCP film for a circuit substrate having a low coefficient of linear thermal expansion and excellent dimensional stability, without excessively impairing excellent basic performance possessed by the liquid crystal polyester, such as mechanical characteristics, electrical characteristics, and heat resistance. The method for manufacturing an LCP film for a circuit substrate at least comprising: a composition provision step of providing an LCP resin composition at least containing 100 parts by mass of a liquid crystal polyester and 1 to 20 parts by mass of a polyarylate; a film forming step of T-die melt-extruding the LCP resin composition to form a T-die melt-extruded LCP film having a coefficient of linear thermal expansion (α2) in a TD direction of 50 ppm/K or more; and a pressurizing and heating step of subjecting the T-die melt-extruded LCP film to pressure and heat treatment to obtain an LCP film for a circuit substrate having a coefficient of linear thermal expansion (α2) in the TD direction of 16.8±12 ppm/K.

The present invention is directed to biodegradable sheets and straws formed from a composition comprising a first biodegradable polymer selected from the group consisting of PBAT, PBS, PLA and combinations thereof; and a second biodegradable polymer selected from the group consisting of PBS, PLA, PCL, PBSA, PBAT and combinations thereof, wherein the first biodegradable polymer is different from the second biodegradable polymer and wherein the straws or sheets have a thickness of 100-250 microns.

A gas barrier film that includes at least a film base material including a polyester resin having a butylene terephthalate unit as a main constituent unit, and one or more metal oxide layers wherein the gas barrier film has a heat shrinkage rate in the machine direction (MD direction) after heating for 30 minutes at 150° C. of 0.6% or more but less than 3.0%, the heat shrinkage rate being represented by the following formula: Heat shrinkage rate={(Length before heating−Length after heating)/Length before heating}×100(%).

An amorphous polyester or copolyester composition comprises the reaction product of a crystalline or semicrystalline polyester or copolyester, optionally derived from a recycled waste stream, at least one diol or aromatic diacid or an ester of a diacid or a hydroxycarboxylic acid or a lactone or a dianhydride, and a catalyst, wherein the amorphous composition has a weight average molecular weight of at least 10,000 g/mol (polystyrene equivalent molecular weight) as measured by gel permeation chromatography.

Perovskite-polymer composites including perovskite nanocrystals dispersed in a polymer matrix, wherein the perovskite nanocrystals have an average size of from about nm to about 20 nm. Methods for producing a perovskite-polymer composites that may include contacting a solid material comprising a polymer matrix with a solution comprising a perovskite precursor; allowing the solution to penetrate the solid material to yield a swollen solid material comprising the perovskite precursor dispersed within the polymer matrix; optionally contacting the swollen solid material with an antisolvent; and annealing the swollen solid material to crystallize the perovskite precursor and to yield the perovskite-polymer composite comprising perovskite nanocrystals dispersed in the polymer matrix.

The invention provides a resin molded article containing a wholly aromatic liquid crystalline polyester resin and formed by being subjected to heat treatment, in which the enthalpy change Δ H.sub.1 at the melting point of the first cycle and the enthalpy change Δ H.sub.2 at the melting point of the second cycle of the temperature elevation process measured by a differential scanning calorimeter satisfy Δ H.sub.1/Δ H.sub.2≥2.0, and the dielectric loss tangent measured by the split-post dielectric resonator (SPDR) method at a measurement frequency of 10 GHz is 0.85×10.sup.−3 or less.

A sheet formed from a carbon fiber reinforced thermoplastic resin with a simplified production process and excellent mechanical characteristics, and a production method of said sheet is provided. This sheet is formed from a carbon fiber reinforced thermoplastic resin that contains carbon fibers, dichloromethane, and a thermoplastic resin containing at least one of a polycarbonate resin and a polyarylate resin, and the content of the dichloromethane contained in the sheet is 10-10,000 ppm by mass.