US 2003/0116057 A1 · Dispersion of ultrafine metal particles and process for producing the same

Abstract

The present invention relates to a liquid dispersion of metal ultrafine particles, which can maintain a desired flow ability even at a high concentration, which is free of any aggregation between fine particles and which can be concentrated. This liquid dispersion is used in, for instance, multilayer distributing wires of, for instance, IC substrates and internal distributing wires of semiconductor devices. If using, as a dispersant, at least one member selected from the group consisting of alkylamines, which are primary amines and whose main chain contains 4 to 20 carbon atoms, carboxylic acid amides and amino-carboxylic acid salts, metal ultrafine particles having a particle size of not more than 100 nm are individually or separately dispersed in the resulting liquid dispersion. The liquid dispersion of metal ultrafine particles in which the metal ultrafine particles having a desired particle size are individually or separately dispersed can be prepared by bringing metal vapor into contact with organic solvent vapor, adding a dispersant to a liquid collected after cooling the vapor mixture, subsequently optionally subjecting the liquid to a solvent-substitution step; or by bringing metal vapor into contact with mixed vapor of an organic solvent and a dispersant, cooling the vapor mixture to collect a liquid product and then, if desired, subjecting the liquid to a solvent-substitution step.

Claims12

Dependent claims

A liquid dispersion of metal ultrafine particles comprising at least one member selected from the group consisting of alkylamines, carboxylic acid amides and amino-carboxylic acid salts as a dispersant and metal ultrafine particles having a particle size of not more than 100 nm and individually dispersed in a liquid.

A method for preparing a liquid dispersion of metal ultrafine particles comprising the steps of:

evaporating a raw metal, according to the evaporation-in-gas technique, in a vacuum in the presence of organic solvent vapor containing at least one organic solvent used for forming ultrafine particles of the metal or in the presence of mixed vapor containing the organic solvent vapor and vapor of at least one member selected from the group consisting of alkylamines, carboxylic acid amides and amino-carboxylic acid salts as a dispersant, to thus bring the organic solvent vapor or the mixed vapor into contact with the metal vapor;
and then
cooling the vapor mixture to collect a liquid containing metal ultrafine particles;
and further,
if the metal vapor is brought into contact with only the organic solvent vapor, adding at least one member selected from the group consisting of alkylamines, carboxylic acid amides and amino-carboxylic acid salts as a dispersant to the collected liquid, to thus give a desired liquid dispersion in which metal ultrafine particles having a particle size of not more than 100 nm are individually or separately dispersed.

2 more elements

Dependencies are inferred from the claim text.

Dispersion of ultrafine metal particles and process for producing the same

Life of this patent

Dispersion of ultrafine metal particles and process for producing the same

Life of this patent

Abstract

Claims12