Abstract: A zipper 3 (translator's comment: the zipper should be coded as 11 instead of 3) is stuck on the opening part 2 side of a packaging bag 1 and a heat-sealed part 12 is formed in the outer side from the zipper 3 (translator's comment: the zipper should be coded as 11 instead of 3) to seal the packaging bag 1. A band-shaped unsealing tape 3 is stuck, in parallel to the opening part 2, on one inner surface of the packaging bag 1 in an area between the zipper 3 (translator's comment: the zipper should be coded as 11 instead of 3) and the heat-sealed part 12. A cutout part 4 is formed on a surface opposite to the surface with the unsealing tape 3 stuck thereon at the end part of the unsealing tape 3. A pair of cut-in parts 5 are formed on the packaging bag 1 at the end part of the unsealing tape 3.

Abstract: A process for the production readily slidable films which are stretched films. The process comprises (a) uniaxially stretching in a machine direction a pre-molded product comprising a composition of a styrene polymer having a high degree of syndiotactic configuration compounded with 0.001 to 1% by weight of inorganic filler particles with an average particle diameter of 0.01 to 3 .mu.m, or simultaneously, biaxially stretching the premolded product in the machine direction and the transverse direction and (b) subsequently uniaxially restretching the premolded product in the traverse direction or simultaneously, biaxially restretching the premolded product in the machine direction and the transverse to produce a film having a surface roughness Ra of 0.005 to 0.03 .mu.m, and a static friction coefficient .mu.s of 0.3 to 1.0. The readily slidable films have high heat resistance, mechanical strength and electrical insulating properties and are excellent in sliding properties and smoothness.

Abstract: A magnetic recording medium having a magnetic layer on at least one side of a base film which is a stretched film of styrene polymer having a high degree of syndiotactic configuration or a composition thereof or a laminate film containing the stretched film, wherein linear expansion coefficient is not more than 5.times.10.sup.-5 /.degree. C. and static friction coefficient is not less than 0.3 and not more than 1.0 is disclosed.The magnetic recording medium has good sliding properties, smoothness, heat resistance and moisture resistance, is excellent in dimensional stability to temperature and moisture, and has good coersive force, thus can be highly densified.

Abstract: A photographic film which comprises (A) a stretched film of a styrene polymer having a syndiotactic configuration or a composition containing it, wherein thickness is 20 to 500 .mu.m, haze is not more than 3% and moisture expansion coefficient is not more than 1.times.10.sup.-6 /% RH, and (B) a photosensitive layer, which is light and excellent in mechanical properties, is disclosed.

Abstract: The invention relates to processes for producing biaxially oriented single-layered and multilayered films. The biaxially oriented single-layered film receives stresses in the range of 500 kg/cm.sup.2 to 1500 kg/cm.sup.2 each in the machine and transverse directions of the film. The multilayered film receives stresses in the range of 300 kg/cm.sup.2 to 1250 kg/cm.sup.2 each in the machine and transverse directions of the film. Thus, the molding stability in biaxial orientation of a nylon film is improved and the thickness accuracy of a resulting film is improved.

Abstract: An electrical insulating film which comprises a styrene polymer having a syndiotactic configuration and containing not more than 1,000 ppm of residual aluminum derived from the catalyst used in the production of the styrene polymer, and not more than 3,000 ppm of residual styrene monomer, and a condenser comprising metal electrodes and the above film which is 0.5 to 30 .mu.m thick and has crystallinity of not less than 25%, are disclosed.

Abstract: The present invention relates to a method of and an apparatus for manufacturing biaxially oriented film. A tubular original film which has been extruded by an extruding die is biaxially oriented by heat and air injected to the inside portion thereof being conveyed to nip rolls each having an individual circumferential speed. The temperature of heat to be applied to the film is controlled on the basis of the detected film thickness for the purpose of obtaining a uniform film thickness distribution. Furthermore, the film can be made uniform by adjusting the outer diameter of the bubble-shaped oriented film by adjusting the distance between two sets of nip rolls on the basis of the measured width of the film. In addition, when the thus-oriented film is subjected to a heat treatment, temperature of heat is arranged to be a predetermined temperature as to prevent adhesion of the films.