Abstract: A biaxially oriented polypropylene film is described. The n-heptane-insoluble content of the film has a chain isotactic index, measured by .sup.13 C-NMR spectroscopy, of at least 97%. In addition, a process for the production of the polypropylene film and the use of the film are described.

Abstract: A biaxially oriented polypropylene film is described. The base ply of the film essentially consists of a polypropylene prepared by means of a metallocene catalyst. This polypropylene is distinguished by a mean isotactic block length of greater than 40, an n-heptane soluble fraction of less than 1% and a ratio of the weight average molecular weight M.sub.w to the number average molecular weight M.sub.n of less than 4.

Abstract: A polyolefin film which includes at least one layer containing polyolefin and cycloolefin polymer (COP), where the cycloolefin polymer is amorphous and has a mean molecular weight M.sub.w in the range from 200 to 100,000, and this mean molecular weight M.sub.w of the cycloolefin polymer is at most 50% of the mean molecular weight M.sub.w of the polyolefin, and the cycloolefin polymer is a homopolymer or a copolymer containing at most 20% by weight of comonomer.

Abstract: A biaxially oriented polypropylene film is described. The base ply of the film essentially consists of a polypropylene prepared by means of a metallocene catalyst. This polypropylene is distinguished by a mean isotactic block length of greater than 40, an n-heptane soluble fraction of less than 1% and a ratio of the weight average molecular weight M.sub.w to the number average molecular weight M.sub.n of less than 4.

Abstract: A biaxially oriented polypropylene film is described. The base ply of the film contains at least 90% by weight of a polypropylene prepared by means of a metallocene catalyst. This polypropylene is distinguished by a mean isotactic block length of greater than 40, an n-heptane soluble fraction of less than 1% and a ratio of the weight average molecular weight M.sub.w to the number average molecular weight M.sub.n of less than 4.

Abstract: A process for the production of biaxially oriented polypropylene films which include at least one layer is described, in which a propylene polymer B is heated in an extruder and the melt of the propylene polymer B is extruded through a flat sheet die and the melt emerging from the flat sheet die is taken off on one or more rolls and is solidified to give a prefilm and this prefilm is stretched in the longitudinal and transverse direction. A propylene polymer or a propylene polymer mixture A is heated and melted in a second extruder and the melt of the propylene polymer or of the propylene polymer mixture A is fed to the two sides of the propylene polymer melt B so that both melts are extruded together and simultaneously through the flat sheet die.

Abstract: Disclosed are a novel photosensitive recording material and a method for using the recording material in the production of planographic printing plates. The recording material comprises a support and a negative-working photosensitive layer that contains a diazonium salt polycondensation product as the photosensitive compound and, in addition, a colorless inorganic pigment which is insoluble in water and organic solvents and which has an average particle diameter from 1 to 20 .mu.m. The pigment is present in a quantity from 0.01 to 2% by weight, relative to the non-volatile constituents of the layer, and is evenly distributed in the layer. Due to the pigment content, a rough layer surface is formed, which has the effect of reducing the time required for creating a vacuum in a vacuum frame into which the recording material is mounted. The presence of the pigment in the layer also produces an improved tonal rendering in the print obtained.

Abstract: SO.sub.2 is extracted from air or other gas mixtures to obtain a water solution, and oxidation is induced in the liquid phase to obtain chemi-luminescence which is photoelectrically detected. The going into solution of SO.sub.2 is enhanced by using e.g. Na.sub.2 HgCl.sub.4. KMnO.sub.4, Cerium (IV) sulfate or other oxidizers are used to produce chemiluminescence. The oxidizer is presented in a water solution which may, for example, be atomized into a gas containing SO.sub.2.