Borosilicate glass compositions

• US 4,537,703 A
• Filed: 12/19/1983
• Issued: 08/27/1985
• Est. Priority Date: 12/19/1983
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Hormadaly, Jacob
• Primary Examiner(s): McCarthy, Helen M.
• Application Number:
  US06/562,966
• Time in Patent Office: 617 Days
• Field of Search: 501/77, 501/16-18, 501/20, 501/58, 501/65, 501/21, 252/518
• US Class Current: 252/519.1
• CPC Class Codes: C03C 3/064 containing boron
• CPC Class Codes: H01C 17/0658 composed of inorganic material

Abstract

The invention is directed to a barium borosilicate glass which is free of Bi, Cd and Pb. The glass, which also contains small amounts of NiO, is especially useful as a binder for thick film resistor compositions to be used for making low end resistors.

Claims

1. A glass which is suitable for use as a binder in high end resistors, which is substantially free of Bi, Cd and Pb and on a molar basis consists essentially of:

A. 50-85% of glass forming materials consisting of 25-50% B₂ O₃, 15-40% SiO₂, and 0.1-5% SnO₂, and

B. 50-15% of glass modifying materials consisting of 10-30% BaO, 0-12% MgO and 1-10% NiO, providing that

(1) the mole ratio B₂ O₃ /SiO₂ ≧

0.8; and

(2) Σ

(B₂ O₃ +SiO₂)≧

50.

2. The glass of claim 1 in which the Group A materials constitute 65-75% and the Group B materials constitute 35-25%.

3. A composition which is comprised of 95-99% wt. of the glass of claim 1 and 5-0.1% wt. of a metal flouride selected from the group consisting of CaF₂, BaF₂, MgF₂, SrF₂, NaF, LiF, KF and NiF₂ and mixtures thereof.

4. A printable thick film resistor composition comprising a dispersion in organic medium of an admixture of finely divided particles of (a) 95-55% wt. tin oxide pyrochlore-based material and (b) 5-45% wt. of the glass of claim 1 or the composition of claim 3.

5. A resistor comprising a patterned thin layer of the composition of claim 4 which has been fired in a nonoxidizing atmosphere to effect volatilization of the organic medium and liquid phase sintering of the glass.