US 12,448,486 B2
Formulation of CNT-containing siloxanes containing silicic acid
Torsten Gottschalk-Gaudig, Mehring (DE); and Claudia Kirschner, Stubenberg (DE)
Appl. No. 17/773,181
Filed by WACKER CHEMIE AG, Munich (DE)
PCT Filed Oct. 30, 2019, PCT No. PCT/EP2019/079695
§ 371(c)(1), (2) Date Apr. 29, 2022,
PCT Pub. No. WO2021/083514, PCT Pub. Date May 6, 2021.
Prior Publication US 2022/0380551 A1, Dec. 1, 2022
Int. Cl. C08G 77/20 (2006.01); B33Y 70/10 (2020.01); C08K 3/04 (2006.01); C08K 3/36 (2006.01)
CPC C08G 77/20 (2013.01) [B33Y 70/10 (2020.01); C08K 3/041 (2017.05); C08K 3/36 (2013.01); C08K 2201/001 (2013.01); C08K 2201/005 (2013.01); C08K 2201/006 (2013.01); C08K 2201/011 (2013.01)] 20 Claims
 
1. An electrically conductive, CNT-containing siloxane composition, comprising:
a) 0.1-5% by weight of carbon nanotubes (CNTs);
b) 70-97.9% by weight of at least one siloxane selected from compounds of general formula (I)
(SiO4/2)a(RxSiO3/2)b(Rx2SiO2/2)c(Rx3SiO1/2)d  (I),
wherein the radicals Rx are independently of one another selected from the group consisting of (i) hydrogen, (ii) —CH═CH2, (iii) unsubstituted or fluorinated C1-C20-hydrocarbon radical, (iv) phenyl radical and (v) —OH and wherein the indices a, b, c and d indicate the number of the respective siloxane unit in the compound and independently of one another represent an integer in the range from 0 to 100 000, wherein a+b+c+d≥2;
c) 1-20% by weight of at least one hydrophobic silica which is surface-silylated with at least one organosilicon compound selected from organosilanes of formula (IV) and organosilazanes of formula (V)
R1R2R3Si—Y  (IV),
R1R2R3Si—NH—SiR1R2R3  (V),
wherein the radicals R1,R2,R3 are each independently selected from halogenated or unsubstituted C1-C24-hydrocarbon radicals;
wherein the radical Y is selected from the group consisting of (i) halogen atom, (ii) —ORx and (iii) —OC(═O)ORx, wherein Rx is in each case selected from the group consisting of (i) hydrogen and (ii) substituted or unsubstituted C1-C24-hydrocarbon radical, wherein substituted is to be understood as meaning that at least one CH2 group, but not the one bonded to silicon, may be replaced by —O—; and
d) 0-5% by weight of other fillers;
wherein the proportions are based on the total weight of the composition and the components a) to d) sum to 100% by weight; and
wherein the composition has a specific resistance of <20 Ω*cm based on 1% by weight of CNT.