| 摘要 |
<p>1473847 Low friction polyester films IMPERIAL CHEMICAL INDUSTRIES Ltd 5 July 1974 [25 July 1973] 35364/73 Heading B5B [Also in Division C3] A biaxially oriented and heat set film is prepared from a composition comprising a linear polyester and 0À01 to 10% by weight, based on the composition, of an inert particulate additive comprising two pyrogenic particulate materials each having a mean primary particle size of up to 100 mÁ, one of the particulate materials possessing a positive electrical charge and the other possessing a negative electrical charge. The example describes preparing a film possessing good "slip" and optical properties from a polyethylene terephthalate composition containing a mixture of pyrogenic silica and pyrogenic alumina.</p> |
