GB839584A - A process for solidifying epoxy or phenolaldehyde resins - Google Patents

Abstract

<PICT:0839584/IV (a)/1> <PICT:0839584/IV (a)/2> <PICT:0839584/IV (a)/3> <PICT:0839584/IV (a)/4> <PICT:0839584/IV (a)/5> <PICT:0839584/IV (a)/6> Liquid epoxy or phenolaldehyde resins of melting points 30-180 DEG C. are solidified by a continuous process in which the resin is cooled under pressure between two internally-cooled rotating smooth rolls of a roller mill, the speed and temperature of the surface of the rolls and the clearance between the rolls being correlated in such a way that a transportable film, solidified at least on the surface, emerges from between the rolls, whereupon the resinous film is subsequently cooled and broken up into smaller pieces. An epoxy resin derived from bisphenol A may be so treated. The clearance between the rolls is preferably not greater than 1 mm. and usually lies between 0.25-0.6 mm., while the roller surface speed may be between 2-50 m./min., especially between 5-20 m./min. A distributing device may be used to spread the liquid resin over the width of the rolls, and the resin may be cooled, preferably on a conveyer belt, only to such a degree that the film is flexible. As shown, liquid resin is discharged from a vessel 1 via cock 2 between the cooled rolls 3, 4 of a roller mill. A distributing device may consist of a unilaterally serrated trough (Fig. 2a), or heated distributing rolls 11, 12. The film emerging from the nip of the rolls may be cooled on a conveyer belt 8, or by passing downward along a guide roll 16, with the use of forced air cooling if desired, or on one of the rolls 4 (Fig. 3a). The film may then be broken up with a pin mill 9, 17, or with a scraper 15, 151.