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US 2021/0189138 A1Published application
Nanoparticle dispersions
AssigneeSun Chemical Corporation
InventorIan Michael Whitehead
Life of this patent
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Abstract
A method for preparing a dispersion of nanoparticles of a solid organic dye or pigment in a liquid carrier, the method comprising continuously mixing: at least one solution or slurry containing a reactant precursor for the solid organic dye or pigment in an organic or other solvent with the liquid carrier in a counter current mixing reactor whereby to obtain reaction of the reactant precursor and formation of the solid organic dye or pigment as a dispersion of nanoparticles in the liquid carrier and solvent mixture; optionally, removing unreacted reactant precursor and/or by-product from the dispersion when present; and optionally, concentrating the dispersion.
Claims20
1:
- A method for preparing a dispersion of nanoparticles of a solid organic dye or pigment in a liquid carrier, the method comprising continuously mixing:
- at least one solution or slurry containing a reactant precursor for the solid organic dye or pigment in an organic or other solvent with the liquid carrier in a counter current or concurrent mixing reactor whereby to obtain reaction of the reactant precursor and formation of the solid organic dye or pigment as a dispersion of nanoparticles in the liquid carrier and solvent mixture;
- optionally, removing unreacted reactant precursor and/or by-product from the dispersion when present;
- and
- optionally, concentrating the dispersion.
2 more elements
2:
- A method according to claim 1, wherein the at least one solution or slurry and/or the liquid carrier contains a wetting agent and/or a dispersant.
3:
- A method according to claim 1, further comprising adding a wetting agent and/or a dispersant to the dispersion.
4:
- A method according to claim 1, wherein the method provides a dispersion of nanoparticles of median (Z) diameter between 100 nm to 300 nm, for example, between 100 nm and 150 nm.
5:
- A method according to claim 1, wherein the method provides a dispersion having unimodal polydispersity.
6:
- A method according to claim 1, wherein the method provides a solid content of the dispersion of solid organic dye or pigment greater than 5.0 wt/wt % and less than 15 wt/wt % of the dispersion.
7:
- A method according to claim 1, wherein the method provides a dispersion having a dynamic light scattering (DLS) polydispersity index between 0.1 and 3.0.
8:
- A method according to claim 1, wherein the method comprises controlling one or more of nanoparticle size, and polydispersity by selection in the or each organic or other solvent, the liquid carrier, the concentration of reactant precursors in the or each solution or slurry and/or in the liquid carrier, the temperature and pressure of the or each solution or slurry and/or liquid carrier, the residence times of the or each solution or slurry and/or the liquid carrier, and the ratio of the flow rates of the or each solution or slurry and the liquid carrier in the reactor.
9:
- A method according to claim 1, wherein the liquid carrier comprises water.
10:
- A method according to claim 9, wherein the organic solvent is one or more of ethyl acetate, ethanol, methanol, diethyl ether, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetone, ethylene glycol, propylene glycol and isopropyl alcohol.
11:
- A dispersion of nanoparticles of a solid organic dye or pigment in a liquid carrier, obtained or obtainable by the method of claim 1.
12:
- A dispersion of nanoparticles of a solid organic dye or pigment in a liquid carrier, wherein the nanoparticles consist essentially of the solid organic dye or pigment.
13:
- A dispersion of nanoparticles of a solid organic dye or pigment in a liquid carrier, wherein the nanoparticles consist essentially of the solid organic dye or pigment and a wetting agent for the nanoparticles.
14:
- A dispersion according to claim 11, comprising less than 5 wt/wt % of a dispersant.
15:
- A dispersion according to claim 11, having a solid content of nanoparticles greater than 3 wt/wt % and less than 20 wt/wt %.
16:
- A dispersion according to claim 11, which has unimodal polydispersity.
17:
- A dispersion according to claim 11, wherein the nanoparticles have median (Z) diameter between 100 nm and 300 nm, for example, between 100 nm and 150 nm.
18:
- A dispersion according to claim 11, wherein the liquid carrier comprises water.
19:
- An ink concentrate for digital inkjet printing, comprising the dispersion of claim 11.
20:
- A cosmetic paste, comprising the dispersion of claim 11.