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.

Novel or improved microporous single or multilayer battery separator membranes, separators, batteries including such membranes or separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are provided. In accordance with at least certain embodiments, a multilayer dry process polyethylene/polypropylene/polyethylene microporous separator which is manufactured using the inventive process which includes machine direction stretching followed by transverse direction stretching and a subsequent calendaring step as a means to reduce the thickness of the multilayer microporous membrane, to reduce the percent porosity of the multilayer microporous membrane in a controlled manner and/or to improve transverse direction tensile strength. In a very particular embodiment, the inventive process produces a thin multilayer microporous membrane that is easily coated with polymeric-ceramic coatings, has excellent mechanical strength properties due to its polypropylene layer or layers and a thermal shutdown function due to its polyethylene layer or layers. The ratio of the thickness of the polypropylene and polyethylene layers in the inventive multilayer microporous membrane can be tailored to balance mechanical strength and thermal shutdown properties.

Novel or improved microporous single or multilayer battery separator membranes, separators, batteries including such membranes or separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are provided. In accordance with at least certain embodiments, a multilayer dry process polyethylene/polypropylene/polyethylene microporous separator which is manufactured using the inventive process which includes machine direction stretching followed by transverse direction stretching and a subsequent calendering step as a means to reduce the thickness of the multilayer microporous membrane, to reduce the percent porosity of the multilayer microporous membrane in a controlled manner and/or to improve transverse direction tensile strength. In a very particular embodiment, the inventive process produces a thin multilayer microporous membrane that is easily coated with polymeric-ceramic coatings, has excellent mechanical strength properties due to its polypropylene layer or layers and a thermal shutdown function due to its polyethylene layer or layers. The ratio of the thickness of the polypropylene and polyethylene layers in the inventive multilayer microporous membrane can be tailored to balance mechanical strength and thermal shutdown properties.

Disclosed are compositions and methods for multilayer films, which, in one embodiment may comprise a core layer comprising at least 50 wt. % of high-density polyethylene. Further, the multilayer film may include a first skin layer comprising at least 80 wt. % of high-density polyethylene, and a second skin layer comprising either: (i) one or more low-density polyethylenes; or (ii) one or more polypropylene-based copolymers. The multilayer film may be oriented in at least one direction.

A microporous membrane wipe and a method of using such microporous membrane wipe are disclosed. The microporous membrane wipe may be uniaxially or biaxially oriented microporous membrane. The uniaxially or biaxially oriented microporous membrane may be made from one or more block and/or impact copolymers of polyethylene and/or polypropylene. A method of using such a microporous membrane wipe for skin oil blotting is also disclosed. Further disclosed is a method of using such a microporous membrane wipe for cleaning a surface for the removal of fingerprints, smudges and the like, where such surfaces may include, for example, eyeglasses, electronics, cell phones, displays, optical devices, camera lenses, microscope lenses and other precision optics, and/or the like.

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 porous polytetrafluoroethylene membrane in which an absolute value of a difference in lightness between one principal surface and the other principal surface is 1.0 or more, where the lightness is lightness L* of CIE 1976 (L*, a*, b*) color space specified in JIS Z8781-4: 2013. The porous polytetrafluoroethylene membrane may be colored black or gray. The porous polytetrafluoroethylene membrane provided can have properties with a reduced coloring-induced deterioration.

An improved nozzle box is disclosed having side walls spaced apart from each other, a base and a ventilation wall spaced apart from it, thereby forming an interior space. A plurality of ventilation openings arranged offset to each other is provided in the ventilation wall, the nozzle box is provided on its ventilation wall with a plurality of protrusions that are raised by at least a height (H) in relation to the sections of ventilation wall or the top side or surface of the ventilation wall the sections being located adjacent to the protrusions, the ventilation openings are configured raised in the region of the protrusions in relation to the top side or surface of the ventilation wall and/or the ventilation wall includes in the transverse direction (Q) of the nozzle box opposing side flanges that overlap the side walls of the nozzle box outside the interior space of the nozzle box.

A method is for producing a coextruded and biaxially stretched composite film using a novel combination of stretching and relaxation steps. A corresponding composite film has little or no shrinkage.