The impact of mineral oil filling on the safe application of silicone sealants
Silicone sealant not only has excellent UV aging resistance and weather aging resistance, but also has excellent high and low temperature resistance and a wide range of substrate adhesion properties. It has good adhesion to most building materials such as glass, metal, stone and concrete. Since the 1980s, silicone sealants have begun to enter my country’s construction and decoration industry. Over the past 30 years, they have shown a large-scale and high-speed development trend. Currently, they have been widely used in the fields of building curtain walls, interior decoration, insulating glass, doors and windows, etc. Wide range of applications.
However, due to intensified market price competition, raw material prices have risen sharply. In order to reduce production costs, some companies have begun to use cheap mineral oil instead of polydimethyl Silicone. Mineral oil, commonly known as white oil or white mineral oil, is a mixture of liquid hydrocarbons obtained from petroleum refining, mainly a mixture of saturated naphthenes and paraffins. The excellent aging resistance and weather resistance of silicone sealant are due to the fact that it is mainly composed of polydimethylsiloxane, which is the material basis for its excellent performance. If the content of polydimethylsiloxane is reduced, its various Performance will be severely affected.
For silicone structural adhesives, the industry standard JG/T 475-2015 “Silicone Structural Sealants for Building Curtain Walls” stipulates: 1) Quality changes : Thermal weight loss ≤ 6.0%, 2) Alkane plasticizer: Infrared spectrum detection, no alkane plasticizer. GB/T 31851-2015 “Detection Methods for Alkane Plasticizers in Silicone Structural Sealants” provides relevant regulations on the detection methods for alkane plasticizers. Regarding glue for insulating glass, GBT 29755-2013 “Elastic Sealant for Insulating Glass” and GB 24266-2009 “Silicone Structural Sealant for Insulating Glass” both stipulate that the thermal weight loss is less than or equal to 6.0%. The above standards impose relatively strict restrictions on the possible addition of mineral oil to silicone structural sealants and silicone sealants for insulating glass through corresponding index requirements. However, the current standards for weather-resistant sealants, door and window sealants, etc., have not fully clarified the restrictions on filling mineral oil. There are still a considerable number of weather-resistant sealants, door and window sealant products on the market filled with mineral oil.
And oil-filled glue is always a construction killer, destroying the beauty of the building and damaging the sealing of the building. The following editor will take you to analyze the adverse effects of silicone sealant filled with mineral oil.
1. Weather-resistant sealant oil-filled case
Silicone weather-resistant sealant is mainly used to seal curtain wall joints to ensure the air tightness and water tightness of the curtain wall. Adding mineral oil to silicone weather-resistant sealant will cause premature failure of the weather-resistant sealant, causing water and air leakage in the curtain wall, increasing energy consumption, and affecting normal use. If the weather-resistant sealant added with mineral oil comes into contact with the insulating glass, the added mineral oil will migrate and penetrate into the insulating glass, causing the sealing butyl glue of the insulating glass to be dissolved and oil flow will occur (see Figure 2).
2 Hollow rubber oil-filled case
The main function of the secondary sealant of insulating glass is to maintain the stability of the insulating glass structure. Adding mineral oil to the insulating glue will cause premature failure of the insulating glass and cause condensation in the insulating glass; when mineral oil migrates into the inner cavity of the insulating glass, oil flow and rainbow phenomena will occur (see Figure 3). If mineral oil is added to the insulating glass structural sealant, the aging performance and bonding performance will decrease sharply. Once the bonding fails, the entire outer piece of the insulating glass may fall off.
3 Cases of oil-filled door and window glue
Door and window sealant is mainly used for seam sealing of doors and windows to ensure the airtightness and watertightness of doors and windows. The door and window sealant fails, causing water leakage in the doors and windows (see Figure 4), increasing energy consumption and affecting normal use.
1. Conclusion
1) Filled mineral oil has many problems in practical applications, which affect the performance and life of the glue; it may also be affected by the migration of mineral oil. The performance and lifespan of other adjacent materials will cause greater losses to users.
2) Filling with mineral oil will increase my country’s carbon emissions and pollute the environment. As a petroleum by-product, mineral oil has poor compatibility with silicone sealant, and its volatilization will cause unnecessary serious impact on the environment.
3) The author hereby recommends that users never choose silicone sealant products filled with mineral oil.
=”word-wrap: break-word; font-size: 16px;”> 1) Filling mineral oil has many problems in practical applications, which affects the performance and life of the glue; it is also possible that the migration of mineral oil may affect other The performance and lifespan of adjacent materials will cause greater losses to users.
