Abstract: Thin self-supporting green compact, less than 25.mu. thick, containing an inorganic substance and as a binder a polymer with a weight average molecular weight of more than 400,000, which polymer in a suitable solvent can form a thermoreversible gel above room temperature, the volume fraction of the inorganic substance being more than 45% relative to the total amount of binder plus inorganic substance and a process to prepare such green compacts.

Abstract: A process is disclosed for producting thin stretched films having a thickness between 0.1 and 20 .mu.m from polyolefins of ultrahigh molecular weight by dissolving the polyolefin in a solvent, shaping the solution at a temperature above the solution temperature of the polyolefin to a tape, cooling the tape to a temperature below the solution temperature to obtain gelation and stretching the gelled tape. In this process the gelled tape is initially subjected to a preliminary orientation in one direction, under solvent removal, and is then stretched in a direction essentially perpendicular to the direction of preliminary orientation, at elevated temperature, followed by final stretching to obtain the finished thin films. This process makes possible the production of films which are free from pores, that is to say transparent and which posses high Young's moduli, high tensile strengths and favorable values for elongation at break.