Patent ID: 8048193
Filing Date: 2011-11-01
Classification: B01J,B22F,B82Y,Y10S

Abstract:
1. A method for producing gold colloid comprising: a nucleation step of forming nuclear colloidal particles having a particle size of 12 nm to 17 nm, by adding a first reducing agent to a first gold salt solution; and a growth step of growing nuclear colloidal particles by adding a second gold salt and a second reducing agent to the solution of the nuclear colloidal particles, wherein the growth step is performed at least once; a citrate is used as the first reducing agent and an ascorbate is used as the second reducing agent; in a single growth step, the second gold salt and the ascorbate are added in amounts represented by the following formulas, respectively: where N N C is the number of colloidal particles in a nuclear colloidal solution (1L); V is the total volume (L) of a nuclear colloidal solution; N Ma is the molecular weight of the second gold salt; Mb is the molecular weight of the second reducing agent; and α and β are constants satisfying 1.0≦α≦2.5, 2.0≦β≦5.7 and in said growth step, the ascorbate and the second gold salt are added simultaneously dropwise.