In a gas-barrier aluminum deposition film according to one embodiment of the present invention, a seed coating layer containing functional groups of at least one type selected from among a hydroxyl group (—OH), an amine group (—NH), and a carboxylic acid group (—COOH) is formed on a thermoplastic plastic base film to form a seed molecular layer that enables uniform deposition of aluminum, such as AlOx or AlNx, through chemical reaction, on a surface of the coating layer, with aluminum atoms vaporized at the initial stage of aluminum deposition, thereby inducing uniform deposition of an aluminum layer to be subsequently deposited. Therefore, it is possible to provide a deposited film having superior oxygen and water vapor barrier properties compared to existing aluminum deposition films.

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.

A principal film comprising a first polymeric component wherein the principal film has: (1) first and second major faces; (2) a land portion wherein the principal film is capable of thermally-induced self- forming; and (3) one or more modification zones, each comprising a central portion and a rim portion surrounding the central portion and being surrounded by land portion, wherein the average thickness of each rim portion is greater than the average thickness of the land portion surrounding the modification zone, the average thickness of each central portion is less than the average thickness of the land portion surrounding the modification zone and is greater than zero. Also methods for making such films and articles comprising such films.

Provided are a white polyester film including a polyester and white particles having an average primary particle diameter of 0.20 to 0.40 μm, in which a content of the white particles is 1.0% to 5.0% by mass with respect to the total mass of the film, a ratio of agglomerated particles having particle diameters of 0.40 to 0.80 μm in a direction parallel to a surface direction of the film on the cross-section of the film to the total number of primary particles and agglomerated particles of the white particles dispersed in the film is 10% to 20% by number, and a concentration of terminal carboxyl groups is 6 to 30 equivalents/ton, a method for manufacturing the same, a solar cell back sheet, and a solar cell module.

A multilayer film includes an inner layer system having a first surface and a second surface; a first skin layer bound to the inner layer system at the first surface of the inner layer system; and a second skin layer bound to the inner layer system at the second surface of the inner layer system. The inner layer system contains ≥50.0 wt % of a first ethylene-based polymer being a high-density polyethylene having a density of ≥940 and ≤970 kg/m.sup.3; and one or both of the first or the second skin layer(s) is a sealing layer including a second ethylene-based polymer being a linear low-density polyethylene comprising polymeric moieties derived from ethylene and from 1-hexene or 1-octene, having a density of ≥890 and ≤915 kg/m.sup.3. The multilayer film is a bi-directionally oriented film, wherein the orientation in both directions is introduced in the solid state.

A method for manufacturing a crosslinked polyolefin separator and the crosslinked polyolefin separator obtained therefrom are provided. The method includes non-grafted polyolefin having a weight average molecular weight of 300,000 or more and silane-grafted polyolefin having a weight average molecular weight of 300,000 or more. The method minimizes gel formation, a side reaction occurring in an extruder during the manufacture of the separator, and provides the separator having a uniform surface.

A method for producing a polyolefin-based porous film includes an (A) step: a raw fabric forming step for forming a non-porous raw fabric from a polyolefin-based resin composition, a (B) step: an MD cold stretching step for cold stretching the non-porous raw fabric obtained in the (A) step at a temperature of −20° C. to (Tm−30)° C. (Tm is a melting point (° C.) of the non-porous raw fabric) in an extruding direction (MD) of the raw fabric to make the raw fabric porous; a (D) step: a TD cold stretching step for cold stretching a film processed in the (B) step in a direction (TD) perpendicular to the MD, and an (H) step: a thermal fixing step, in the above order.

A biaxially orientated polyester film has a P.sub.L/V.sub.L ratio of 0.3 to 1.2, P.sub.L and V.sub.L representing the average diameter of the convex portions and the average diameter of the concave portions, respectively, that are defined on the basis of a slice level with a height of 0 nm (reference plane) in a roughness curve determined for at least one surface using a three dimensional surface roughness meter, and the convex portions accounting for an area ratio of 30% to 51% of the reference plane. The biaxially oriented polyester film is excellent in travelling property, slitting property, and dimensional stability, and serves, when used for magnetic recording medium production, to provide a high density magnetic recording medium having a smooth magnetic layer, suffering little dimensional change due to variations in environmental parameters such as temperature and humidity or due to storage, and having good electromagnetic conversion characteristics with little dropout.

A biaxially stretched polypropylene film for capacitors which has protrusions on both sides and has a thickness (t1[μm]) of 1 μm to 3 μm, wherein Formulae (1) to (4) are satisfied by an A-side as one film surface and a B-side as another film surface:
|Pa−Pb|≧200;  (1)
0.350≦Pa/SRzA≦0.700;  (2)
500 nm≦SRzA≦1,200 nm;  (3)
50 nm≦SRzB≦500 nm;  (4)
wherein, in Formulae (1) to (4), Pa is a number per 0.1 mm.sup.2 of protrusions on the A-side, Pb is a number per 0.1 mm.sup.2 of protrusions on the B-side, SRzA is a ten-point average roughness of the A-side, and SRzB is a ten-point average roughness of the B-side.

To provide a biaxially oriented polyester film that has extremely low content of antimony, excellent hygiene, few foreign substances, excellent transparency and heat resistance, and is excellent in printability, workability, and productivity. A biaxially oriented polyester film characterized by a content of antimony in the film of 10 ppm or less, a content of phosphorus in the film of 25 ppm or more and 75 ppm or less, an intrinsic viscosity of the film of 0.51 dl/g or more and 0.70 dl/g or less, and a number of defects with a size of 1 mm or more is 1.0 or less per 1000 square meters of the film.