Polarizing film
AssigneeAgfa-Gevaert
InventorKarl-Heinz Aleksander Ostoja Starzewski
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Abstract
A polarizing film of improved blocking position based on polyvinyl alcohol which comprises polyacetylene as the light-polarizing substance is obtained if such a film is heated for at least 10 s at a temperature of between 100.degree. C. and 300.degree. C.
Claims10
A polarizing film of improved blocking position based on polyvinyl alcohol containing polyacetylene as the light-polarizing substance, obtainable by stretching a polarizable film 4- to 13-fold to obtain a polarizing film and thereafter treating the film for from 10 seconds up to 60 days at a temperature of between 100.degree. C. and 300.degree. C. with the exclusion of oxygen wherein the time and temperature of treatment are sufficient to raise the degree of polarization at 400 nm by at least 4%.
A process for the production of a polarizing film of improved blocking position based on polyvinyl alcohol which comprises polyacetylene as the light-polarizing substance, which comprises stretching a polarizable film 4- to 13- fold to obtain a polarizing film and thereafter treating the film for from 10 seconds up to 60 days at a temperature of between 100.degree. C. and 300.degree. C. with the exclusion of oxygen wherein the time and temperature of treatment are sufficient to raise the degree of polarization at 400 nm by at least 4%.
Dependencies are inferred from the claim text.