Thick-film conductor paste for automotive glass

1. A thick-film composition comprising:

(a) conductive metal;

(b) crystallized glass;

(c) amorphous glass; and

(d) organic medium, and fine particles of cobalt oxide.

2. The composition as in claim 1 wherein said conductive metal is selected from the group consisting of silver, gold, platinum, palladium, and mixtures thereof.

3. The thick-film composition as in any one of claims 1 wherein said amorphous glass is present in the amount of 0.1 to 10.0 wt %, based on the weight of the total composition, including the organic medium.

4. The thick-film composition as in any one of claims 1 wherein said conductive metal is present in the amount of 50 to 90 wt %, based on the weight of the total composition, including the organic medium.

5. The thick-film composition as in any one of claims 1 wherein said crystallized glass comprises at least 3 wt % based on the weight of the total composition, including the organic medium.

6. The thick-film composition as in claim 2 wherein the conductive metal is silver and wherein the particle size of said silver is between 0.1 to 15 microns.

7. The thick-film composition of claim 1 wherein the composition of said amorphous glass comprises, based on total composition; SiO 2 36.9%, ZrO 2 3.0%, B 2 O 3 3.0%. Na 2 O 1.3%, Li 2 O 3.0%, Bi 2 O 3 46.8%, TiO 2 3.0%, K 2 O 3.0% in weight % based on the weight of the total composition.

8. The thick-film composition of claim 1 wherein said fine particles of cobalt oxide are present in the amount of at least 3 wt %, based on the total composition, including the organic medIum.

9. The method of using the thick-film composition of claim 1 , to form conductive patterns on a rigid substrate, comprising the following steps:

(a) screen printing said thick-film composition through a mesh screen onto a rigid substrate;

(b) drying said composition;

(c) firing said substrate and composition so as to form a conductive pattern on the substrate.

10. The method of using the thick-film composition of claim 1 , in the manufacture of an electrically conductive pattern on a substrate, comprising the following steps:

(a) screen printing said thick-film composition through a mesh screen onto a rigid substrate;

(b) drying said composition;

(c) firing said substrate and composition so as to form a conductive pattern on to substrate; and

(d) removing the organic medium.

11. The method of using the thick-film composition of claim 1 for automotive glass applications, comprising the following steps:

(a) screen printing said thick-film composition through a mesh screen onto a rigid, fiat unformed window glass;

(b) drying said composition at about 150 degrees C.;

(c) firing said glass and composition at about 650 degrees C. so as to form a conductive pattern on the glass;

(d) shaping the glass by compression into a mold and quenching the glass by rapid cooling;

(e) removing the organic medium by vaporization and pyrolysis and

(f) sintering the glass and metal conductive powder.

12. A vehicle comprising a windshield defroster system said windshield defroster system comprising a conductive element wherein said conductive element is formed from the thick-film composition as in any one of claims 1 , 2 – 8 .