Borosilicate glass compositions
AssigneeE. I. Du Pont de Nemours and Company
InventorJacob Hormadaly
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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 CoO, is especially useful as a binder for thick film resistor compositions to be used for making high-end resistors.
Claims5
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 25-55% B.sub.2 O.sub.3, 15-40% SiO.sub.2 ;
- 0-10% ZrO.sub.2 and 0-5% SnO.sub.2, and
- B. 50-15% of glass modifying materials consisting of 10-30% BaO, 1-10% CoO and 0-12% oxides of alkaline earth metals having atomic numbers 12-38, providing that
- (1) the mole ratio B.sub.2 O.sub.3 /SiO.sub.2 =.gtoreq.0.8;
- and
- (2) .SIGMA. (B.sub.2 O.sub.3 +SiO.sub.2).gtoreq.50.
A composition which is comprised of 95-99.9% wt. of the glass of claim 1 and 5-0.1% wt. of a metal fluoride selected from the group consisting of CaF.sub.2, BaF.sub.2, MgF.sub.2, SrF.sub.2, NaF, LiF, KF and NiF.sub.2 and mixtures thereof.
Dependencies are inferred from the claim text.