Abstract: The stretch film for rustproof stretch packaging has an appropriate roll tack and sufficient self-tack to adhere to and package an object, such as a steel coil. This stretch film has an overall density of 0.870 to 0.935 g/cm3 and is composed of polyolefin resin, rust preventive agents, and an effective amount of a polyolefin polyol adhesive with a number average molecular weight of 500 to 5,000 g/mol. When the film has at least three layers, one surface layer has a density of 0.850 to 0.920 g/cm3, and another surface lever on the opposite side of the film and intermediate layers between them have greater densities. The polyolefin polyol adhesive and the rust preventive agents are present at least in the low density surface layer.

Abstract: A rustproof stretch film having an appropriate roll tack, and a self tack adhering to an object to be packaged without peeling when such an object is, for instance, a steel coil. The rustproof stretch film consists of a single layer film or multi-layer film composed of polyolefine resin and includes low molecular weight polyolefin polyol functioning as adhesives, and rust preventive agents, whose overall density is within a range of 0.870-0.935 g/cm3.

Abstract: The present invention relates to battery parts comprising molded pieces made of polyolefin resin, whose surface to be bonded are treated so as to have at least one functional group selected from the group consisting of hydroxyl group, carboxyl group, carbonyl group, fluorosulfuryl group, sulfonic group and its metallic bases, said molded pieces being bonded together with reactive hot-melt adhesive.

Abstract: A process for producing a porous film comprising polyolefin resin, a filler and an ester of dipentaerythritol having a ratio 3 to 70% residual OH groups.

Abstract: A process for producing a porous film or sheet, which comprises melt-molding a composition prepared by compounding 100 parts by weight of a polyolefin resin with 25 to 400 parts by weight of a filler and 1 to 100 parts by weight of a liquid or waxy hydrocarbon polymer into film or sheet, and stretching the resulting film or sheet.

Abstract: A polyester film is disclosed which comprises a polyester mainly consisting of polyethylene terephthalate and an additive amount of granular calcium terephthalate anhydride particles having a specific volume shape factor. The average particle diameter and additive amount of the granular calcium terephthalate anhydride particles may be controlled so that the film is particularly suitable as a metallized film or a condenser film.

Abstract: A polyester film is disclosed which comprises (a) a polyester mainly consisting of polyethylene terephthalate which includes first inert particles being precipitated in the polyester-forming reaction system and having an average particle diameter of 1 to 3 microns and which shows a solution haze of 25 to 75% and (b) an additive amount of second inert substance particles which are added to said polyester (a) insoluble in said polyester (a), inert to the polyester-forming reaction and have an average particle diameter of 1 to 5 microns. The film is useful as a base of a magnetic tape.