Composition comprising a comb copolymer
The invention relates to a composition comprising a) a polymer a) comprising polymerized units of a N-vinyl lactam, b) a comb copolymer b) having a polymer backbone based on a vinyl aromatic compound and an ethylenically unsaturated polymerizable carboxylic anhydride, and having at least two polyalkylene oxide side chains, and c) a carbon-based material.
1 . A composition comprising
a) a polymer a) comprising polymerized units of N-vinylpyrrolidone,
b) a comb copolymer b) having a polymer backbone based on a vinyl aromatic compound comprising one or more of styrene, vinyl toluene, vinyl xylene, or vinyl ethylbenzene and an ethylenically unsaturated polymerizable carboxylic anhydride or acid comprising one or more of maleic anhydride, itaconic anhydride, citraconic anhydride, or fumaric acid, or esters of the foregoing anhydrides, and having at least two polyalkylene oxide side chains,
c) an electrically conductive carbon-based material comprising at least one of carbon black, carbon nano tubes, graphite, carbon fibers, graphene, and fullerenes, and
d) at least one organic solvent comprising N-methyl pyrrolidone,
wherein the weight ratio of polymer a) to copolymer b) is in a range of 25:75 to 75:25.
2 . The composition according to claim 1 , wherein the weight average molecular weight of polymer a) is in the range of 2,000 to 500,000 g/mol.
3 . The composition according to claim 1 , wherein the polyalkylene oxide side chains of comb polymer b) are linked to the polymer backbone via an amide group or an imide group.
4 . The composition according to claim 1 , wherein the comb copolymer b) comprises further functional groups comprising at least one of hydroxyl, carboxylic acid, salt of carboxylic acid, tertiary amine, salt of tertiary amine, and quaternary ammonium.
5 . The composition according to claim 1 , wherein the weight average molecular weight of comb polymer b) is in the range of 4,000 to 100,000 g/mol.
6 . The composition according to claim 1 , wherein the water content of the composition is in the range of 0.0 to 5.0% by weight, calculated on the total weight of the composition.
7 . The composition according to claim 1 , wherein the carbon-based material comprises at least one of carbon black and carbon nano tubes.
8 . A process of preparing a carbon-based material dispersion comprising the steps of
i) providing a composition comprising
a) a polymer a) comprising polymerized units of a N-vinylpyrrolidone, and
b) a comb copolymer b) having a polymer backbone based on a vinyl aromatic compound comprising one or more of styrene, vinyl toluene, vinyl xylene, or vinyl ethylbenzene and an ethylenically unsaturated polymerizable carboxylic anhydride or acid comprising one or more of maleic anhydride, itaconic anhydride, citraconic anhydride, or fumaric acid, or esters of the foregoing anhydrides, and having at least two polyalkylene oxide side chains; wherein the weight ratio of polymer a) to copolymer b) is in a range of 25:75 to 75:25
ii) providing an electrically conductive carbon-based material comprising at least one of carbon black, carbon nano tubes, graphite, carbon fibers, graphene, and fullerenes,
iii) mixing the components provided in steps i) and ii) with at least one organic solvent comprising N-methyl pyrrolidone and exerting shear force to prepare a carbon-based material dispersion.
9 . A rechargeable electrical battery having an electrode comprising the composition according to claim 1 .
10 . The rechargeable electrical battery according to claim 9 , wherein the comb copolymer b) comprises further functional groups comprising at least one of hydroxyl, carboxylic acid, salt of carboxylic acid, tertiary amine, salt of tertiary amine, and quaternary ammonium.
11 . The composition according to claim 1 , wherein polymer a) comprises polymerized units of N-vinylpyrrolidone, and wherein the comb copolymer b) comprises further functional groups comprising at least one of hydroxyl, carboxylic acid, salt of carboxylic acid, tertiary amine, salt of tertiary amine, and quaternary ammonium.
12 . The composition according to claim 1 , wherein the combined amount of polymer a) and comb copolymer b) is 1 to 40% of the weight of the electrically conductive carbon-based material.