The secret of silicone sealant is revealed, is cheap white oil really good?silicone teether company

　　In addition to silicone products, silicone sealant is a very common sealing liquid glue that is currently practical. Since it needs to withstand the displacement change of the joint width caused by the external environment in the construction joint during the application process, the silicone sealant has a Good ability to withstand joint displacement, can withstand changes in joint width for a long time without cracking. However, under the background of the current rising prices of raw materials, there are quite a lot of white oil-filled silicone rubber products on the market. They attract users at low prices, but in actual use, various performance declines are very obvious, which cannot satisfy the sealant. The requirements of corresponding standards will bring serious quality problems and even hidden safety hazards to users.

　　What is white oil?

　　White oil, commonly known as paraffin oil, white oil and mineral oil, is obtained from crude oil by atmospheric and vacuum fractionation, solvent extraction and dewaxing, and hydrorefining (Figure 1). It is mainly a mixture of saturated naphthenes and paraffins. See Figure 1 for details. It has good oxidation stability, chemical stability, light stability, colorless, odorless, and does not corrode fiber textiles.

　　The production process of white oil mainly includes sulfur trioxide refining method and hydrorefining method.

　　1. At the end of the 19th century, white oil was produced abroad, using concentrated sulfuric acid or oleum sulfonation method. The white oil produced by this method is of unstable quality, low yield, large loss of raw materials, large acid consumption, and a large amount of acid. The slag is difficult to handle, and the environmental pollution is very serious. Later, the sulfur trioxide sulfonation method technology appears, which greatly reduces the acid consumption, and the white oil yield improves to some extent, but the problem of environmental pollution is still not solved.

　　2. In the early 1960s, hydrotreating technology began to be applied to the production of white oil. Hydrorefining technology has little environmental pollution, high yield of white oil, stable quality, and can produce high-viscosity, high-grade white oil. Since then, the quality and output of white oil have improved dramatically.

　　Why do some silicone product manufacturers add white oil to silicone rubber?

　　The core main reason: reduce costs and obtain more benefits. Due to the relatively high price of dimethyl silicone oil, with the fierce market competition in the sealant industry, in order to reduce costs, some sealing silicones start with plasticizers and use white oil instead of dimethyl silicone oil as the plasticizer for silicone sealants. , the silicone glue made is called "white oil glue".

　　When white oil is used as a plasticizer, it can not only increase the gloss of the silicone sealant, but also improve the extrusion speed, and the cost is lower than that of the silicone sealant using dimethyl silicone oil as a plasticizer. However, white oil is composed of small molecular saturated alkanes, with relatively low molecular weight and easy volatilization. It is added to the silicone sealant as a plasticizer. Over time, it will completely volatilize or exude from the silicone sealant. , thereby losing the effect of the plasticizer, and eventually leading to a sharp increase in the hardness of the silicone sealant, embrittlement and even cracking in severe cases.

　　On the surface, these low-cost "white oil-filled adhesives" are not much different from silicone sealants that are not filled with white oil. Some products even have a good appearance, very bright, fast curing speed, and initial curing mechanics. Performance is also good. However, with the prolongation of use time, the difference between "white oil-filled glue" and silicone sealant without white oil will gradually appear. See Figure 2 for details.

　　Silicone sealant is mainly composed of three parts: silicone base polymer, filler and auxiliary agent. The excellent weather resistance of silicone sealant is mainly determined by the silicone base polymer with silicon-oxygen-silicon bond as the main chain. The content of the silicone base polymer decreases, and its durability will be seriously affected! Among the three, the silicone base polymer has a high content and a high unit price, and its cost accounts for more than 70% of the cost of the entire silicone sealant.

　　What is the harm of white oil glue?

　　After filling with white oil, most of the properties of the silicone adhesive (such as UV resistance, adhesion, thermal weight loss, hardness, etc.) will decrease.

　　The compatibility of white oil with the silicone sealant system is poor, and the white oil added to the silicone sealant can easily migrate and penetrate from the silicone sealant system, resulting in poor weather resistance of the silicone sealant, and ultimately cause the above-mentioned serious hazards to appear. "White oil glue is an inferior product. Although the price is low, once a problem occurs, the cost of rework, maintenance, and brand loss in the later period will be several times or even dozens of times the purchase cost. Not only does the cost not save, but it adds additional costs. A lot of costs, not worth the loss!

　　message

　　Cost saving is the eternal theme of every enterprise, and product price has always been the focus of everyone's attention. But you can't do anything to create ultra-low-priced products. Those who choose inferior raw materials and use fake and inferior products to counterfeit brands and other behaviors that harm users have seriously disrupted the market order and endangered the healthy development of the industry. Would you really choose such a "high cost-effective" white oil glue at the expense of product quality?

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