Nano-talc with hydrophobic coating
AssigneeNGX, Inc.
InventorsMei Li, Qiping Zhong
Life of this patent
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Abstract
In one embodiment the invention is a hydrophobic nano-talc composition that is the reaction product of nano-talc with an ammonium, pyridinium or phosponium salt. The composition is characterized by a carbon content of about 5 to about 25 wt %. The compositions are useful in preparing nano-talc/polymer composites. In another embodiment, the invention is a process for preparing a nano-talc composition of the invention.
Claims17
A hydrophobic nano-talc composition comprising the aqueous reaction product derived from reaction of a plurality of nano-talc particles having an specific surface area of about 70 to 500 m2/g, a number average particle size of 50 to about 200 nm and an isoelectric point of about 2.5 to about 3.5;
- and an alkylammonium salt, alkylpyridinium salt, or alkylphosphonium salt, wherein the alkyl group is selected from the group C12-C22 straight-chain or branched-chain alkyl group interrupted or uninterrupted by one or two oxygen atoms.
A method of providing a hydrophobic nano-talc composition comprising:
- combining (a) an aqueous solution comprising about 0.5 to 10 wt % of an alkylammonium salt, alkylpyridinium salt or alky phosphonium salt wherein the alkyl group is selected from the group C12-C22 straight-chain or branched-chain alkyl group interrupted or uninterrupted by one or two oxygen atoms;
- with (b) an aqueous nano-talc slurry comprising a plurality of nano-talc particles having a specific surface area of about 70 to 500 m2/g, a number average particle size of 50 to about 200 nm and an isoelectric point of about 2.5 to about 3.5;
- with mixing at a reaction temperature sufficient to maintain the alkylammonium salt, alkylpyridinium salt or alkyl phosphonium salt in solution, to provide a hydrophobic nano-talc precipitate,
- washing sufficiently the hydrophobic nano-talc precipitate with wash water, to provide a wash water effluent with a measured conductivity below about 400 μs/cm, followed by,
- optionally, dewatering the hydrophobic nano-talc precipitate to provide a hydrophobic nano-talc cake, and
- drying the hydrophobic nano-talc precipitate or hydrophobic nano-talc cake to provide the hydrophobic nano-talc composition.
Dependencies are inferred from the claim text.