abstract |
1489635 Heat treating polymers TOYO SEIKAN KAISHA Ltd 3 March 1975 8809/75 Heading C3P [Also in Division B5] An ethylene-vinyl alcohol copolymer having a vinyl alcohol content (X) of 50-75 mole per cent is heated at a temperature (Y 3 ) given by the relationship: for a time in minutes (t) given by: The resulting polymer has a main endothermic peak (in differential thermal analysis) at a temperature (Y 1 ) substantially of and a subsidiary endothermic peak at a temperature (Y 2 ) given by: The polymer can contain units of a comonomer such as propylene. The polymers have improved gas permeation resistance and can be used as packaging material. |