Patent ID: 6372159
Filing Date: 2002-04-16
Classification: C07C,C09K,G02F,Y10T

Abstract:
A UV-protected electrochromic solution comprising(a) an electrochromic redox component comprising a weakly colored or colorless combination of at least one oxidizable substance RED1 that releases electrons at an anode and in so doing undergoes transition into a substance OX1 and at least one reducible substance OX2 that accepts electrons at a cathode and in so doing undergoes transition into a substance RED2, wherein at least one of OX1 or RED2 is accompanied by an increase in the absorbance in the visible region of the spectrum and thereby becomes colored and the combination is restored to the weakly colored or colorless form after charge equalization, with the proviso that at least one of the substances RED1 is linked covalently to at least one of the substances OX2 by a bridge; and (b) at least one UV absorber selected from the group consisting of unsubstituted and substituted cinnamic esters and unsubstituted and substituted 2-hydroxybenzophenones.