| 摘要 |
<p>1372811 Polyethylene terephthalate films CELANESE CORP 2 Jan 1973 [3 Jan 1972] 201/73 Heading B5B [Also in Division C3] Abrasion resistant biaxially oriented polyethylene terephthalate film is characterized by an intrinsic viscosity in excess of 0À3 dl/g.; 0À01-0À5% of inert additive particles having an average particle size of 10-1000 mÁ and from 0À02-1% by weight of calcium carbonate particles having an average particle size of 0À5- 30 Á, the inert additive and CaCO 3 being substantially completely homogeneously dispersed throughout the film. The film may be made by dispensing the additives therein, extruding, biaxially stretching and heating at 190-240‹ C. to crystallize. Specified additives are SiO 2 talc and calcined and hydrated aluminium silicate. Examples 1-5 describe the dispersal of additives in the film and its preparative detail. Examples 6-10 describe the biaxial orientation on a revolving polished drum at 75-130‹ C., followed by heat setting at 190-240‹ C., cooling and winding on a mandrel.</p> |
