Fine silver particle dispersion

Patent metadata

Field	Value
Publication number	US-11441010-B2
Application number	US-201715724378-A
Country	US
Kind code	B2
Filing date	Oct 4, 2017
Priority date	Oct 4, 2017
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

This disclosure relates to a fine silver particle dispersion comprising: (i) 60 to 95 wt. % of fine silver particles, wherein particle diameter (D50) of the fine silver particles is 50 to 300 nm, (ii) 4.5 to 39 wt. % of a solvent; and (iii) 0.1 to 3 wt. % of a resin, wherein the glass transition temperature (Tg) of the resin is 70 to 300° C., wherein the weight percentages are based on the weight of the fine silver particle dispersion.

First claim

What is claimed is:

1. A fine silver particle dispersion comprising:
(i) 60 to 95 wt. % of fine silver particles, wherein particle diameter (D50) of the fine silver particles after being dispersed in solvent is 50 to 300 nm, (ii) 4.5 to 39 wt. % of a solvent; and
(iii) ethyl cellulose resin,
wherein the total amount of ethyl cellulose resin in the dispersion is 0.1 to 0.9 wt. %, and includes an ethyl cellulose resin having a weight-average molecular weight in the range of from 23,000 to 180,000,
the weight percentages are based on the weight of the fine silver particle dispersion,
the fine silver particle dispersion comprises no glass frit, and
the fine silver particle dispersion does not contain terpene and does not contain silver microparticles having an average primary particle diameter of 1μm or more.

2. The fine silver particle dispersion of claim 1 , wherein primary particle diameter of the fine silver particles is 1 to 180 nm, the primary particle diameter being measured by image analysis of an image taken with a scanning electron microscope.

3. The fine silver particle dispersion of claim 1 , wherein the fine silver particles are coated with an organic protective material.

4. The fine silver particle dispersion of claim 3 , wherein the organic protective material is amine with carbon number from 8 to 12.

5. The fine silver particle dispersion of claim 1 , wherein boiling point of the solvent is 150 to 350° C.

6. The fine silver particle dispersion of claim 1 , wherein the solvent is selected from the group consisting of diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol monobutyl ether acetate, and a mixture thereof.

7. The fine silver particle dispersion of claim 1 , wherein the ethyl cellulose resin and the solvent are such that a viscosity of a mixture of the ethyl cellulose resin and the solvent at a weight ratio (resin:solvent) of 1:9 is 0.1 to 30 Pa·s.

8. The fine silver particle dispersion of claim 1 , wherein viscosity of the fine silver particle dispersion is 30 to 350 Pa·s.

9. The fine silver particle dispersion of claim 1 , wherein the ethyl cellulose resin has a weight-average molecular weight in the range of from 44,046 to 180,000.

10. The fine silver particle dispersion of claim 1 , wherein the ethyl cellulose resin has a weight-average molecular weight in the range of from 50,000 to 77,180.

11. The fine silver particle dispersion of claim 1 , wherein the total amount of ethyl cellulose resin consists of the ethyl cellulose resin having the weight-average molecular weight in the range of from 23,000 to 180,000.

12. The fine silver particle dispersion of claim 10 , wherein the total amount of ethyl cellulose resin consists of the ethyl cellulose resin having the weight-average molecular weight in the range of from 50,000 to 77,180.

13. A fine silver particle dispersion consisting of:
(i) 60 to 95 wt. % of fine silver particles, wherein particle diameter (D50) of the fine silver particles after being dispersed in solvent is 50 to 300 nm, (ii) 4.5 to 39 wt. % of solvent selected from the group consisting of diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol monobutyl ether acetate; and
(iii) ethyl cellulose resin,
wherein the total amount of ethyl cellulose resin in the dispersion is 0.1 to 0.9 wt. %, and includes an ethyl cellulose resin having a weight-average molecular weight in the range of from 23,000 to 180,000,
the weight percentages are based on the weight of the fine silver particle dispersion,
the fine silver particle dispersion does not contain glass frit and does not contain silver microparticles having an average primary particle diameter of 1μm or more.

Assignees

• Dowa Electronics Materials Co Ltd

Inventors

• Teragawa Shingo
• Hinotsu Takashi
• Hui Dave
• Wolfe Michael Stephen
• Glicksman Howard David
• Yang Haixin

Classifications

• B22F1/0545

  Dispersions or suspensions of nanosized particles · CPC title

• C08K2201/005

  Additives being defined by their particle size in general · CPC title

• C08L1/284

  with hydroxylated hydrocarbon radicals · CPC title

• C08K2003/0806

  Silver · CPC title

• B22F9/24 Primary

  starting from liquid metal compounds, e.g. solutions · CPC title