Borosilicate glass, useful for producing glass tubes and for fluorescent lamps and low-pressure gas discharge lamps, comprises silicon dioxide, boron trioxide, aluminum oxide, sodium oxide, potassium oxide and calcium oxide

摘要

#CMT# #/CMT# The borosilicate glass comprises silicon dioxide (SiO 2) (70-80 mol.%), boron trioxide (B 2O 3) (10-14 mol.%), aluminum oxide (Al 2O 3) (0.8-1 mol.%), sodium oxide (Na 2O) (3-4 mol.%), potassium oxide (K 2O) (3-4 mol.%), calcium oxide (CaO) (0.3-0.6 mol.%), titanium dioxide (TiO 2) (3-4 mol.%), zirconium dioxide (ZrO 2) (0-1 mol.%), and refining agents such as antimony oxide (Sb 2O 3) (0-0.15 mol.%), cerium oxide (CeO 2) (0-0.5 mol.%) and tin oxide (SnO 2) (0-0.5 mol.%), where a molar ratio of Na 2O/(Na 2O + K 2O) is less than 0.4-0.06. #CMT# : #/CMT# The borosilicate glass comprises silicon dioxide (SiO 2) (70-80 mol.%), boron trioxide (B 2O 3) (10-14 mol.%), aluminum oxide (Al 2O 3) (0.8-1 mol.%), sodium oxide (Na 2O) (3-4 mol.%), potassium oxide (K 2O) (3-4 mol.%), calcium oxide (CaO) (0.3-0.6 mol.%), titanium dioxide (TiO 2) (3-4 mol.%), zirconium dioxide (ZrO 2) (0-1 mol.%), and refining agents such as antimony oxide (Sb 2O 3) (0-0.15 mol.%), cerium oxide (CeO 2) (0-0.5 mol.%) and tin oxide (SnO 2) (0-0.5 mol.%), where a molar ratio of Na 2O/(Na 2O + K 2O) is less than 0.4-0.06. A temperature of a softening point is greater than 540[deg] C, where the log (eta ) is 12. The borosilicate glass has a thermal conductivity of >= 0.93 W/m.K, an average coefficient of thermal expansion of 4.3-0x 10 ->6/K, and a processing temperature of 1070[deg] C. #CMT#USE : #/CMT# The borosilicate glass is useful for producing glass tubes and for fluorescent lamps and low-pressure gas discharge lamps (all claimed). #CMT#ADVANTAGE : #/CMT# The borosilicate glass has improved processing properties. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Components: The molar ratio of B 2O 3/(B 2O 3+ alkalioxide) is = 0.65. A product of (B 2O 3.(lithium oxide + Na 2O + K 2O)) is less than 100. The mole ratio of (CaO + MgO + BaO)/(Li 2O + Na 2O + K 2O) is less than 0.1. The molar ratio of Al 2O 3/(Li 2O + Na 2O + K 2O) is present in a range of 0.1-0.2. The borosilicate glass contains no lithium oxide, lead(II) oxide, barium oxide, and magnesium oxide. The molar ratio of SiO 2/Al 2O 3is greater than 70.