Process for producing flame retardant high temperature resistant shaped articles
AssigneeLenzing Aktiengesellschaft
InventorsRobert Vodiunig, Norbert Rossak, Manfred Schobesberger, Klaus Weinrotter
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Abstract
A process for producing high-temperature resistant and flame-retardant shaped articles of polyimide polymers of the general formula ##STR1## wherein A represents a four-valent group and R represents a divalent aromatic group, by heating a manipulatable sheet-like structure to a temperature in the glass transition range of between 280.degree. C. and 360.degree. and pressing it at pressures ranging between 10 bar and 500 bar. The polyimide shaped bodies obtained have densities of at least 1.30 g/cm.sup.3. Preferably, they may be completed as sheets having uniform thicknesses of between 0.1 and 6 mm.
Claims5
A process for producing flame-retardant high-temperature resistant shaped articles, comprising
- providing a manipulatable sheet-like structure based on polyimide fibers of the general formula ##STR6## wherein n is an integer greater than 1 and A represents a four-valent aromatic group selected from the group consisting of ##STR7## in which x is selected from the group consisting of CO, CH.sub.2, O, S, and CF.sub.2 and R comprises at least one of the following divalent aromatic group selected from the group consisting of ##STR8## heating said sheet-like structure to a temperature in the glass transition range of between 280.degree. C. and 360.degree. C. so as to obtain a heated sheet-like structure, and
- pressing said heated sheet-like structure at a pressure ranging between 10 bar and 500 bar by using a shaping means for a time sufficient to sinter said structure.
Dependencies are inferred from the claim text.