| 摘要 |
<PICT:0780289/IV (a)/1> Compositions comprise polyethylene and a drawing aid of the formula: <FORM:0780289/IV (a)/1> where X is a thio, dithio, alkylene dithio or sulphinyl radical and R1 and R2 are alkyl groups, the two R1 and two R2 substituents being the same or different, e.g. bis-(2-methyl-4 - hydroxy - 5 - tert. - butyl phenyl) sulphide, bis - (2 - ethyl - 4 - hydroxy - 5 - tert. - butyl phenyl) sulphide and (2-methyl-4-hydroxy-5-tert. - butyl phenyl)(2 - ethyl - 4 - hydroxy - 5-tert.-butyl phenyl) sulphide. The bis (hydroxyaryl) sulphur compounds may be added before or during extrusion of the polymer to form filaments, films, threads, sheets and bands. Films may be prepared by extrusion in the apparatus shown. The molten composition is forced through a slit 1 adjustable by means of screws 2 and the film is drawn down to the desired thickness, e.g. 1/2 to 1/100 of the slit setting, before entering a quench tank 3 containing a nonsolvent cooling liquid, e.g. water. Preferably an atmosphere of an inert gas, which may be heated above 100 DEG C., is maintained about the film, between the slit and the quench tank, in a chamber 4, which may be provided with baffles to avoid direct impingement of the gas stream on the film.
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