Lead-free glass for automobile rear-windshield demisting-defrosting conductive film

Abstract

The invention relates to a lead-free glass for removing mist and frost of a conductive film of a car tailgate, preparation and application thereof. The weight percentage components of the glass are: 40-70 percent Bi2O3, 0-40 percent B2O3, 0-35 percent ZnO, 0-15 percent SiO2, 0-10 percent Al2O3, 0-10 percent MgO, 0-6 percent CaF2 and 0-3 percent CaO. The preparation includes the processes: according to the weight percentage of each component, each material is weighed , completely mixed and put into a quartz crucible for melting and then the material is poured into a tabletting machine to tabletted into thin sections or poured into cold water; the glass with the shape of flake or grain is put into the ball mill to be ball-milled, sieved, and then bagged; the preparation can be applied to any glass, ceramics, metal seal conforming with an expansion coefficient in the temperature. The glass has suitable and easily adjustable thermal expansion coefficient, suitable softening temperature, excellent chemical stability as well as has strong competitiveness in the aspects of free lead and good performance and wide development prospect of the market.

Description

technical field [0001] The invention belongs to the field of lead-free glass, in particular to the lead-free glass used for defogging and defrosting conductive films on rear windshields of automobiles. Background technique [0002] Lead-free glass for defogging and defrosting conductive film of automobile rear windshield is a kind of low melting point glass, and low melting point glass is an advanced welding material. The material has low melting temperature and sealing temperature (<600°C), good heat resistance and chemical stability, high mechanical strength, and is widely used in electric vacuum and microelectronics technology, laser and infrared technology, high energy physics , Energy, aerospace, automobiles and many other fields have realized the mutual sealing between glass, ceramics, metals and semiconductors. Applied products include cathode ray tube displays, vacuum fluorescent displays, plasma displays, vacuum glass, solar collector tubes, lasers, magnetic mat...

AI Technical Summary

Problems solved by technology

The softening temperature of the glass is 400-430°C, and the coefficient of thermal expansion is 145-170×10 -7 / °C, although the softening temperature of the glass is suitable for low-melt sealing, but the content of alkali metal oxides is high, resulting in poor chemical stability and electrical properties. In addition, the glass has a large thermal expansion coefficient and cannot be used for medium and Sealing with a low expansion coefficient, while containing a small amount of lead, cannot meet the requirements of lead-free, due to the precious metal ZrO 2 The content is relatively high, so there is also no advantage in terms of cost

[0009] The mole percentage of the glass composition disclosed in Japanese Patent No. H7-69672 is: P 2 o 5 25~50%, SnO 30~70%, ZnO 0~25%, on this basis, add B 2 o 3 、WO 3 , Li 2 O, etc., the transition temperature of the glass is 350-450°C, and the coefficient of thermal expansion is greater than 120×10 -7 / °C, the method of using fillers in the patent reduces the expansion coefficient of the glass, but it affects the fluidity and airtightness of the glass when it is sealed, and the chemical stability of the glass is not good.

[0010] U.S. Patent P5153151 discloses a phosphate sealing glass whose molar composition is Li 2 O 0~15%, Na 2 O 0~20%, K 2 O 0~10%, ZnO 0~45%, Ag 2 O 0~25%, Tl 2 O 0~25%, PbO 0~20%, CuO 0~5%, CaO 0~20%, SrO 0~20%, P 2 o 5 24~36%, Al 2 o 3 0~5%, CeO 2 0~2%, BaO 0~20%, SnO 0~5%, Sb 2 o 3 0~61%, Bi 2 o 3 0~10%, B 2 o 3 0-10%, the transition temperature of the glass is 300-340°C, and the coefficient of thermal expansion is 135-180×10 -7 / °C, the disadvantage of this glass is that Tl 2 The toxicity of O is very high. At the same time, the thermal expansion coefficient of glass is relatively large, so it cannot be used for sealing with medium and low expansion coefficients.

[0011] Hitachi Manufacturing Co., Ltd. has announced a vanadium oxide (V 2 o 5 ) is sealing glass, the sealing temperature is less than 400°C, and the coefficient of thermal expansion is 90×10 -7 / °C, but in this glass, lead oxide is a necessary component, which cannot meet the requirements of lead-free. At the same time, it also contains highly toxic thallium oxide