GB464808A - Improvements in the manufacture and production of shaped articles from polymerised vinyl carbazole - Google Patents

Abstract

Articles are produced from polymerized vinyl carbazole or mixtures thereof by subjecting the material to a treatment by which the molecules are orientated in a definite direction, comminuting the resulting material and pressing it at a temperature at which no complete fusion takes place. The mixtures may comprise vinyl carbazole and styrene, butadiene, or vinyl ethers. In order to produce the desired orientation the material may be extruded at temperatures above 200 DEG C. in the form of bands, foils, rods, or tubes, or rolled between hot rollers and subjected to a tensile stress by a second pair of rollers running at a higher speed but at a lower temperature, or formed into thin plates or rods in an injection moulding machine at temperatures above 200 DEG C. the receiving mould being at a temperature between 50 and 200 DEG C. The substances thus produced are comminuted in cross-beater mills, crushers, &c., and the resultant fibrous mass is moulded at temperatures from 180 to 250 DEG C. Softening agents and fillers may be added or insertions of fabric, metal wires, mica leaves or asbestos masses. The fibrous mass may be tableted and preheated to about 225 DEG C. before the final moulding. According to the Provisional Specification the preliminarily formed sheets, instead of being comminuted, may be laid on one another with their molecules orientated in different directions and pressed at temperatures from 200 to 250 DEG C.