The main component of silicone structural sealant is polysiloxane, because the ultraviolet light can not destroy the silicone bond, so the silicone structural sealant has good ultraviolet resistance.
China's silicone structural sealant research and development of the beginning of the 1960s, mainly used for satellite solar cell bonding, the planned economy era is mainly used in the aviation and aerospace industry, 1988, China began to develop aluminum alloy glass curtain wall, in a long period of time are the use of imported structural sealant (GE, DC, DC, etc.) France Rona, Germany Weikai, etc.), China's first batch of national certification of Baiyun, Zhijiang, Central Plains and other 3 factories 4 brands.
The technical requirements of silicone structural adhesive refer to the national standard GB16776-2005 "Silicone structural sealant for construction", which mainly includes 10 technical indicators such as sag, extrudability, applicable period, surface dry time, hop hardness, tensile adhesion, adhesion failure area, thermogravimetric property, cracking and powder. The test mainly refers to the national standard GB/T13477-2003 "Building sealing materials Test",
the American Society for Testing Materials (ASTM) in 1991 issued the first standard on silicone structural sealant ASTMC1184-91, after 1995, 1998 two revisions. Structural adhesive is generally divided into single-component structural adhesive, two-component structural adhesive and single-component acid structural sealant three categories, single-component structural adhesive is mainly used in the structural bonding assembly of building curtain wall, with high modulus, good adhesion to many materials, neutral curing, rapid curing and other characteristics; The two-component structural sealant is a two-component, neutral curing high performance silicone structural sealant suitable for building curtain wall, mainly used for structural applications, with fast curing, high extrusion rate, high modulus, neutral curing, flexible adjustment of mixing ratio and other advantages; Acid structural sealant is a single component, acid curing, specially designed for the glass structure bonding assembly in the building curtain wall, with easy to use, acid curing, high modulus, excellent aging stability, mainly suitable for large plate glass structure bonding, point glass curtain wall.
2.2 Silicone sealant Silicone sealant is mainly divided into four categories: weather-resistant adhesive, general purpose sealant (neutral sealant), anti-pollution sealant (stone glue) and fireproof sealant. The GB14683-2003 technical requirements for silicone building sealant mainly have 10 requirements: appearance quality, density, extrusion, application period, surface drying time, fluidity, low temperature flexibility, adhesion, recovery rate, tensile compression cycle performance. National standard JC/T882-2001 "Sealant for curtain wall glass joints" JC/T884-2001 "Architectural sealant for colored steel plates" makes the following provisions on the technical requirements of weather-resistant sealant:
Appearance; 2. The applicable period index of sealant; 3. Physical properties. 2.3 Weather-resistant adhesive is mainly used in building curtain wall weather-resistant expansion joints, non-structural curtain wall interfaces, most of the building materials such as glass, aluminum, plastic have good adhesion without adverse reactions, has good ozone resistance, ultraviolet performance, can be applied for up to 20 years and basically maintain the original strength and elongation properties. In line with national standard JC/T 882-2001.2.4 General purpose sealant (neutral sealant) is a single component, medium modulus, neutral curing adhesive, mainly divided into general silicone sealant, mildew sealant, engineering sealant three categories, the main characteristics are single component, neutral curing, rapid curing, excellent thixotropy and extrudability, good adhesion.
2.5 Anti-pollution sealant (stone glue) is a caulking sealant mainly suitable for porous materials such as marble and granite that are easy to pollute and difficult to clean after pollution. The technical indicators should comply with the provisions of the national standard GB/T 23261-2009 "Building sealant for stone". At present, the method used to test pollution is the United States ASTM1248-98 "Standard test method for joint sealant pollution for porous substrates", and the use of most stone auxiliaries can also reduce the possibility of stone pollution. The characteristics of stone glue are: single component, neutral curing, good displacement capacity (20%-50%), no pollution to porous materials, good weather resistance.
2.6 Fire retardant sealant is A single component, neutral curing silicone sealant, fire level can reach GB23864-2009 "Fire sealing materials" A level, according to the fire resistance is divided into A1h, A2h, A3h three grades. Materials used to seal or caulk through holes, annular gaps and building gaps in buildings, structures and facilities, which are easy to replace and meet the relevant performance requirements.
2.7 Other kinds of glue In addition to the above four categories, there are some special use of various kinds of glue, such as: epoxy resin glue, planting glue, adhesive steel glue, foamed glue, group Angle glue, universal glue and so on.
