Abstract:
POLYACETALS. I.E. HOMOPOLYMERS OF FORMALDEHYDE OR OF TRIOXANE OR COPOLYMERS OF TRIOXANE WITH MONOFUNCTIONALLY REACTING COMPOUNDS SUCH AS CYCLIC ETHERS OR CYCLIC ACETALS AND POSSIBLY POLYFUNCTIONALLY REACTING COMPOUNDS CAN BE PROTECTED BY ADDITION OF STABILIZERS AGAINST THE ACTION OF HEAT AND OXYGEN. THEY CAN, HOWEVER, BE DEGRADED BY THE ACTION OF ULTRA-VIOLET LIGHT IF THEY CONTAIN LIGHT SENSITIZERS, FOR EXAMPLE ANTHRONE. THE POLYACETALS ARE SUITABLE FOR THE MANUFACTURE OF SHAPED ARTICLES, ESPECIALLY SHEETS.
Abstract:
1410641 Light sensitized oxymethylene polymer composition HOECHST AG 14 Sept 1972 [16 Sept 1971] 42709/72 Heading C3P A composition comprises (a) an oxymethylene polymer, (b) a heat stabilizer and (c) a light sensitizer which is anthrone. Oxidation stabilizers, e.g. bisphenols, may also be present. The compositions are degradable in ultra-violet light and may thus be useful for bags, sheets and sacks. They may be prepared by homogenizing the components in granular or powder form at 150‹ to 250‹ C. In examples, polyformaldehyde and trioxan-ethylene oxide, trioxan-dioxolan and trioxan-ethylene oxide-butanedioldiglycidyl ether copolymers are stabilized with calcium ricinoleate or dicyanodiamide and sensitized with anthrone or (for comparison) with benzophenone or fluorenone.