Glass sealants

Worldwide production capacity of Hquid polysulfides is about 33,000 t with manufacturing sites in the United States, Japan, and Germany. Total consumption is about 28,600 t. Approximately 50% is for insulating glass sealants, 30% for constmction appHcations, and - 10% for aircraft sealants. In addition, - 909 t of the soHd polysulfide mbbers are sold each year. 

The main areas of application for one-component silicone sealants are glazing, structural glazing, construction, sanitary areas and as insulated-glass sealants. All these topics will be covered in the section on specific areas of application (section 6.3.8). 

The potential market for polysulphides is for water-industry sealants, and fuel-resistant sealants and coatings for secondary containments. As a construction, civil engineering and insulating-glass sealant polysulphides have a poor to fair market share. Table 7.1 summarises the specific applications of polysulphide systems in the construction industry. 

Figure 7. Metallographic cross sections of ferritic FeCrMn(Ti/La) steels with glass sealant after 400 h of exposure in Ar-Fl2-Fl20 at 800 °C. a) Si and Al containing steel, b) low Si and...

Post-operation analysis showed that the glass sealant used was of high quality and had hardly suffered in the testing. This would explain that apparently no major leakages occurred and the stack remained in a stable operational mode. 

Insulating Glass Sealant - (Forms structural seal to bond pieces of glass and spacer first high performance organic seal)... 

Modified Si02 glass (sealant and oiddatlon barrier)... 

B. Streete, Gas Med insulating glass sealants, SIGMA Meeting, New Orleans, 1989. 

AI2O3 - B2O3 - Si02-based glass sealant for solid oxide fuel/electrolyzer cells. J. Power Sources, 179, 106-112. 

Sun, T., Xiao, H., Guo, W., and Hong, X. (2010) Effect of AI2O3 content on BaO — AI2O3 — B2O3 — Si02 glass sealant for solid oxide fuel cell. Ceram. Int, 36, 821-826. 

Polysulfide pol5uners resistance to moisture vapor transmission is a positive characteristic for applications like insulating glass sealants, but it is a drawback for one-part moisture curing sealants because it leads to relatively slow cure rates. Toray Thiokol has developed new faster curing one-part compositions based on polysulfides with silylthio end groups (4). 

Most of the polysulfide sales are in Europe, the United States, and Japan. Polysulfide sealants have 83% of the market share of insulating glass sealants in Europe, 35% in the United States, and a total of 60% worldwide. Polysulfides have only a modest share of the building sealant market. Polysulfides are virtually the only sealant specified for aircraft integral fuel tanks worldwide. In addition, they comprise about 90% of other aircraft sealant applications. The total volume used in the aircraft sealant market fluctuates with aircraft construction and repair. 

Haanappel VAC, Shemet V, Vinke IC, Gross SM, Koppitz Th, Menzler N, Zahid M, Quadakkers WJ (2005) Evaluation of the suitability of various glass sealant-alloy combinations under SOFC stack conditions. J Mater Sci 40 1583-1592... 

Figure 33.14 Optical micrographs of the cross sections of perovskite membranes sealed with gold coating + SCHOTT glass sealant 8252 (1) AI2O3 tubes (2) glass seal 8252 (3) membrane wall and (4) MaTecK gold coating [61].

Typical Use - Typical Use Insulating glass sealant for dual seal glass units. ... 

Other insulated glass sealants are designed as hot melt compounds with regular or partially cured butyl as the base. These compounds are either hot pumped into place or are applied in a thermoplastic, preformed tape construction. 

Insulating glass sealants the lower plasticizer content and higher filler content give the higher hardness which is needed for this application. 

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