Lead-free and cadmium-free glass frit compositions for glazing, enameling and decorating
AssigneeOwens-Illinois, Inc.
InventorsJosef Francel, Uriah Horn, Daniel R. Stewart
Life of this patent
Estimating the term…
Abstract
Glass frit compositions are shown that are lead-free, cadmium-free, and zinc-free, the compositions having improved chemical resistance, especially acid resistance (acetic acid) of a loss of generally less than about 1.9% by weight. The compositions contain B.sub.2 O.sub.3, SiO.sub.2, ZrO.sub.2 and rare earth oxides, the weight ratio of ZrO.sub.2 to rare earth oxides being critical and being about 1/1 to 1.4/1.
Claims17
A glass frit composition having a fiber softening point of at least about 535.degree. C., the composition being free of lead, cadmium, and zinc, the composition consisting essentially of the following components in approximate weight percents:
- ______________________________________ Component % ______________________________________ SiO.sub.2 25-32 B.sub.2 O.sub.3 25-32 ZrO.sub.2 10-18 Rare earth oxide 10-18 Li.sub.2 O 0-9 Na.sub.2 O 0-9 K.sub.2 O 0-5 SrO 0-6 F 0-3 CaO 0-3 SnO.sub.2 0-2 WO.sub.3 0-10 ______________________________________
- in which the ratio of ZrO.sub.2 to rare earth oxide is about 1:1 to 1.4:1, the amount of ZrO.sub.2 +rare earth oxide is about 20 to 33 and the amount of Li.sub.2 O, K.sub.2 O and Na.sub.2 O is about 1 to 10, the composition having an alkali resistance of less than about 1% (5% sodium pyrophosphate at 60.degree. C. for 8 hours) and an acid resistance of less than about 1.9% (4% by weight acetic acid for 24 hours at room temperature).
A glass frit composition having a fiber softening point of at least about 535.degree. C., the composition being free of lead, cadmium, and zinc, the composition consisting essentially of the following components in parts by weight:
- ______________________________________ Components [Percent] Parts by Weight ______________________________________ SiO.sub.2 30 B.sub.2 O.sub.3 30 ZrO.sub.2 16 Na.sub.2 O 9 Rare earth oxide (bastnasite) 15 F 2 ______________________________________
- the composition having an alkali resistance of less than about 1% (5% sodium pyrophosphate at 60.degree. C. for 8 hours) and an acid resistance of less than about 1.9% (4% by weight acetic acid for 24 hours at room temperature).
A glass frit composition having a fiber softening point of at least about 535.degree. C., the composition being free of lead, cadmium, and zinc, the composition consisting essentially of the following components in parts by weight:
- ______________________________________ Components [Percent] Parts by Weight ______________________________________ SiO.sub.2 30 B.sub.2 O.sub.3 32 ZrO.sub.2 16 Na.sub.2 O 9 Rare earth oxide (bastnasite) 15 F 4 ______________________________________
- the composition having an alkali resistance of less than about 1% (5% sodium pyrophosphate at 60.degree. C. for 8 hours) and an acid resistance of less than about 1.9% (4% by weight acetic acid for 24 hours at room temperature).
A glass frit composition having a fiber softening point of at least about 535.degree. C., the composition being free of lead, cadmium, and zinc, the composition consisting essentially of the following components in parts by weight:
- ______________________________________ Components [Percent] Parts by Weight ______________________________________ SiO.sub.2 30 B.sub.2 O.sub.3 32 ZrO.sub.2 16 Na.sub.2 O 9 Rare earth oxide (bastnasite) 15 F 2 ______________________________________
- the composition having an alkali resistance of less than about 1% (5% sodium pyrophosphate at 60.degree. C. for 8 hours) and an acid resistance of less than about 1.9% (4% by weight acetic acid for 24 hours at room temperature).
Dependencies are inferred from the claim text.