The present invention relates to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby and, particularly, to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby, wherein the polyimide-based film is useful as a cover substrate for a flexible electronic device since flexure characteristics thereof, represented by yield elongation, are excellent.

The present invention relates to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby and, particularly, to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby, wherein the polyimide-based film is useful as a cover substrate for a flexible electronic device since flexure characteristics thereof, represented by yield elongation, are excellent.

A thermoformable biaxially oriented coextruded polyester film comprising a copolyester base layer B, a first polyester outer layer A1 and a second polyester outer layer A2, wherein said outer layers are disposed on opposite surfaces of said base layer, and wherein: (i) said base layer B comprises a copolyester derived from terephthalic acid (TA) and a second aromatic dicarboxylic acid and one or more diol(s), wherein said second aromatic dicarboxylic acid is present in the copolyester in an amount of from about to 5 about 20 mol % of the acid fraction of the copolyester; (ii) the polyester of each of said outer layers A1 and A2 is selected from polyethylene terephthalate (PET); and (iii) the thickness of the base layer constitutes at least 90% of the total thickness of the coextruded multi-layer polyester film.

Provided is a biaxially oriented polypropylene film that has high stiffness, has excellent heat resistance at a high temperature of 150° C., easily maintains a bag shape when being made into a packaging bag, and has less pitch shift during printing or fewer wrinkles in a sealed portion when being heat-sealed. A biaxially oriented polypropylene film, wherein a stress at 5% elongation (F5) at 23° C. of the biaxially oriented polypropylene film is not lower than 40 MPa in a longitudinal direction and not lower than 160 MPa in a width direction, and a heat shrinkage rate at 150° C. of the biaxially oriented polypropylene film is not higher than 7% in the longitudinal direction and not higher than 16% in the width direction.

A Biaxially Oriented Polyethylene (BOPE) process uses a selected polyethylene having a medium density and a very broad molecular weight distribution. The use of this selected polyethylene facilitates stretching in the BOPE process in comparison to previously used polyethylene resins having a higher density and/or a narrower molecular weight distribution.

The present invention relates to thermoforming food packaging methods and to dual ovenable thermoformed food packages suitable for cooking food products directly in the package in microwave, conventional and convection ovens. These packages are characterized by good hermeticity, clean peelability, self-venting, very good optics and, if shrunk, a very appealing appearance.

It is provided that a method for producing a biaxially oriented polyester film that can be used for industrial and packaging applications. A method for producing a biaxially oriented polyester film, comprising: a step of feeding a polyester resin into an extruder, a step of extruding the molten polyester resin from an extruder to obtain a molten resin sheet at 250 to 310° C., a step of attaching the molten resin sheet closely to a cooling roll by an electrostatic application method to obtain an unstretched sheet, and a step of biaxially stretching the unstretched sheet, wherein the polyester resin fulfills the following (A) to (C): (A) the polyester resin comprises a polyethylene furandicarboxylate resin composed of a furandicarboxylic acid and ethylene glycol; (B) an intrinsic viscosity of the polyester resin is 0.50 dL/g or more; (C) a melt specific resistance value at 250° C. of the polyester resin is 3.0×10.sup.7 Ω.Math.cm or less.

Manufacturing a pre-molded stack of one or more lenses to be installable on a curved substrate such as a vehicle windshield includes placing a moldable stack of one or more lenses and adhesive layer(s) on a mold, applying heat and pressure to the moldable stack to produce a pre-molded stack of one or more lenses from the moldable stack, and removing the pre-molded stack from the mold. The pre-molded stack may have a compound curvature, which may match a curvature of the curved substrate. The mold may be formed using three-dimensional shape data derived from the curved substrate, such as by optically scanning the curved substrate.

A biaxially oriented polyester reflection film according to an embodiment of the present invention includes: a core layer having a plurality of voids, and containing homo-polyester, copolymer polyester, a resin incompatible with polyester, and inorganic particles; and a skin layer formed at least one surface of the core layer, and containing homo-polyester, copolymer polyester, and inorganic particles, wherein the biaxially oriented polyester reflection film is formed to have a plurality of light focusing structures, each of which has a concave center portion, and which are arranged in a grid pattern.

An object of the present invention is to provide a stitched fiber-reinforced substrate material capable of suppressing the formation of microcracks in a fiber reinforced composite material. The stitched fiber-reinforced substrate material of the present invention is a stitched fiber-reinforced substrate material formed by stitching reinforcement fiber sheets made of reinforcement fibers using stitching yarns that exhibit an in-plane shear strength transition rate of 5% or more. The stitching yarn is preferably adhered by an organic compound having a polar group.