| abstract |
In preparing an electrolyte comprising a mixture of poly[2-acrylamido-2-methyl-propanesulfphonic acid] and water in which a pigment is distributed substantially homogeneously, monomer of the formula CH 2 ═CH--CO--NH--C(CH 3 ) 2 --CH 2 --SO 3 H is first dissolved in water with a pigment suspended in it. A polymerization initiator, such as 2,2'-azo-bisisobutyronitrile, is added to the mixture and the polymerization reaction is carried out with agitation, at a temperature in the range from room temperature to 60° C. Finally, part of the water is evaporated from the viscous mass obtained, to give the desired mix. The pigmented electrolyte may be used in electro-optical devices such as electrochromic display cells. |