The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 31, 1989
Filed:
Dec. 19, 1985
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
The invention relates to a variable light transmittance glass board which is an electrochromic cell in principle and is comprised of oppositely arranged two transparent glass substrates each of which is laid with a transparent electrode film, first and second electrochromic layers formed on the two electrode films, respectively, by using tungsten trioxide for the first layer and Prussian blue for the second layer and an electrolyte liquid which fills up the space remaining between the two electrode films. The electrolyte liquid is a solution of a conventional supporting electrolyte such as lithium perchlorate in an organic polar solvent such as propylene carbonate. Durability of both electrochromic layers at elevated temperatures is greatly improved by adding 0.2-3.0 wt % of water to the organic polar solvent. By using one or two auxiliary electrode(s) comprising an electrochemically oxidizable and reducible material and being disposed in a marginal region of the space between the two glass substrates, it is possible to prevent the appearance of the glass board from being marred by partial decomposition of the electrolyte liquid at the initial reduction of one electrochromic layer. A polymer of a conjugated compound, e.g. polytriphenylamine, is very advantageous as the electrochemically active material in each auxiliary electrode.