Patent ID: 8323534

Claim:
A composition consisting essentially of: (a) 10-60 wt % of a polymer selected from the group of amorphous, film-forming polymers with T g less than 100° C.; (b) 40-90 wt % of a plasticizer mixture, wherein the plasticizer mixture consists essentially of: (i) a plasticizer, wherein the plasticizer is soluble in the polymer to at least 45 wt %; (ii) an electrochromophore, wherein the electrochromophore is soluble in the plasticizer to at least 10 wt % and wherein the concentration of the electrochromophore in the composition is from 1 to 30 wt %; (iii) an electron mediator selected from the group consisting of ferrocene, butyl ferrocene, ferrocene carboxylic acid, phenazine and its derivatives, carbazole and its derivatives, phenothiazine and its derivatives, and phenanthroline and its derivatives, wherein the concentration of the electron mediator in the composition is from 0.1 to 10 wt %; and, (iv) a salt selected from the group consisting of lithium chloride, tetrabutylammonium bromide, lithium bis(trifluoromethanesulfonyl)imide, lithium triflate, and lithium hexafluorophosphate, wherein the concentration of the electron mediator in the composition is from 0.1 to 10 wt %, and wherein the melting point of the plasticizer is not above about 0° C., the boiling point of the plasticizer is above about 190° C. at a pressure of 1 atmosphere, and the solubility in the plasticizer of the electron mediator and the salt are each at least 0.5 mg per mg of plasticizer.