Compositions useful for the formation of an antistatic layer or an electromagnetic radiation shield
A liquid composition. The liquid composition comprises (i) particles comprising a complex of a polythiophene and a polyanion, (ii) at least one tetraalkyl orthosilicate, (iii) at least one solvent, and (iv) gallic acid, at least one derivative of gallic acid or a mixture thereof. Also provided are a process for the preparation of a liquid composition, a liquid composition obtainable by such a process, a process for the preparation of a layered body, the layered body obtainable by such a process, a layered body and the use of a liquid composition.
1. A liquid composition comprising:
i) particles comprising a complex of poly(3,4-ethylenedioxythiophene) and an anion of polystyrene sulfonic acid (PEDOT/PSS),
ii) tetraethyl orthosilicate (TEOS),
iii) water or a mixture of water and an alcohol selected from the group consisting of methanol, ethanol, n-propanol and isopropanol, and
iv) a gallotannine, wherein the liquid comprises a dispersion,
wherein the liquid further comprises
v) at least one inorganic acid selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, silicic acid and a mixture of at least two of these inorganic acids, or at least one organic acid selected from the group consisting of acetic acid, formic acid, benzoic acid, p-toluenesulfonic acid, PSS and a mixture of at least two of these organic acids, or a mixture of at least one of these inorganic acids and at least one of these organic acids, or the at least partially deprotonated base form of any of the above mentioned inorganic or organic acids, and
wherein the pH of the liquid composition is in the range from 2.5 to 4, the pH being determined at a temperature of 25° C.
2. The liquid composition according to claim 1 , wherein a conductive layer prepared from the composition has at least one of the following properties (α1) to (α3):
(α1) a sheet resistance in a range from 1×10 2 to 1×10 10 Ω/sq;
(α2) a transmission of at least 98%; and
(α3) a pencil hardness of at least 6H.
3. The liquid composition according to claim 2 , wherein the conductive layer is characterized by all of the properties (α1) to (α3).
4. The liquid composition according to claim 1 , wherein the gallotannine is tannic acid.