Patent ID: 9017578
Filing Date: 2015-04-28
Classification: B01F,B01J,B22F,B82Y

Abstract:
1. A method for producing a metal nanoparticle colloid having metal nanoparticles dispersed in a nonpolar hydrocarbon oil, the metal nanoparticles being coated with organic molecules, wherein all of the metal nanoparticles have a specific shape of particle and a particle size in a specific range and contain almost no foreign matter of metal particles in a shape other than the specific shape of particle, the method comprising the following steps (a) to (d): (a) selecting a specific type of non-magnetic metal material from Cu, Ag, Au, Sn, Bi, Cr, Dy, In, Mn, Nd, Pd, and Zn; (b) selecting, according to the selected specific type of non-magnetic metal material, a specific type of organic molecules having an HLB value in a specific range and having both a hydrophilic group and a lipophilic group, which is a surfactant having an HLB value of less than 9, from an aliphatic amine, a sorbitan fatty acid ester, a polyglycerol fatty acid ester, a mercaptan, a phosphate, an aliphatic phosphoric oxide, an alkylamine fatty acid salt, a polypropylene oxide fatty acid ether, a thiol, a succinic acid polyethyleneamine polypropylene oxide fatty acid ether, a polybutenylsuccinic acid polyamine imide, and polybutenylsuccinic acid ester; (c) mixing the selected specific type of organic molecules into a nonpolar hydrocarbon oil having a vapor pressure of 10 (d) placing the base liquid in a rotatable vacuum drum and charging the specific type of non-magnetic metal material in a crucible provided in the vacuum drum, and depositing the vapor of the non-magnetic metal material on the base liquid which adheres to the inner wall of the vacuum drum and rotates together with the rotating drum under conditions such that the inside of the vacuum drum is under a reduced pressure and the vacuum drum is rotated so that the running speed of the base liquid becomes 10 to 500 mm/s.