Uses of silicone oil defoamer
1. Petroleum industry
Silicone oil defoamer is widely used in the petroleum industry and has become an indispensable and important additive in the production process. Since a large amount of strong foaming surfactants are used in drilling fluids, defoaming agents are not only indispensable for crude oil extraction, but also must be used in the post-crude oil refining process. Home Page: During the crude oil distillation process, silicone oil defoaming agent needs to be used. Secondly, the gas extracted from the top of the tower or the natural gas coming out of the gas well contains impurities such as H2S and CO2. When ethanolamine or (HOCHMeCH2)2NH is used as the H2S absorption liquid circulation A large amount of foam will be generated during operation, which will affect normal production. If silicone oil defoaming agent is added to the amine liquid, high-efficiency continuous operation can be achieved.
In the process of separating aromatic hydrocarbons (benzene, toluene, xylene, etc.) from crude oil fractions, more or less foam is generated during the cracking and hydrogenation reforming reactions. In the hydrocracking process, since water-diethylene glycol is used as the solvent, the latter has a strong tendency to foam, so defoaming agents are required for these processes. In addition, when producing various types of lubricants, due to the addition of floating oil agents, antioxidants, anti-rust agents, solid lubricants and extreme pressure anti-wear agents, etc., they are all surface-active substances and have varying degrees of effects. Foaming effect, so silicone oil defoaming agent needs to be added.
2. Textile industry
The textile industry is one of the sectors that uses the largest amount of silicone oil for defoaming. Among the eight main processes of fabric processing (i.e. spinning, sizing, weaving, desizing, scouring, bleaching, dyeing (tie-dyeing) and finishing) , there are 4 processes (sizing, scouring, dyeing and finishing) that require the use of surfactants and other additives, so there are varying degrees of foam problems. For example, in the fabric printing and dyeing, leveling and bleaching processes, penetrants are often added to the dyeing of thick and dense fabrics to improve dyeing uniformity, but penetrants can easily foam and cause color stains and even waste products; for another example, When printing on nylon silk, solvents can also cause “bubbles” and affect product quality. If silicone oil emulsion defoaming agent is added separately or used together with octanol as defoaming agent, the problem of foam can be solved and the leveling effect and color paste stability can be improved. It should be pointed out that in the process of dyeing and finishing fiber fabrics, there are strict requirements on the quality of defoaming agents used. If the stability of the defoaming agent is not good, oil stains or oil spots may appear on the fabric, causing the product to be degraded or called a waste product. For this reason, the performance of the defoaming agent, bath solution formula, acidity, alkalinity, cleaning temperature and stirring conditions must be carefully selected. For general fabrics, silicone oil emulsion defoaming agents are often used; for high-temperature (above 130°C) dyeing of polyester fiber fabrics, self-emulsifying modified silicone oil defoaming agents are mostly used.
3. Synthetic rubber and resin industry
When using emulsion polymerization to prepare rubber (www.szrl.cc) latex, fatty acid soaps are often used as emulsifiers, resulting in serious foaming problems. Especially after the reaction is completed, the foaming is particularly serious when the unreacted monomer is recovered by stripping. For example, in the process of synthesizing styrene-butadiene latex, acrylonitrile-butadiene-styrene (ABS) copolymer, chloroprene copolymer and phenolic resin, there are varying degrees of foaming problems. Polyether silicone oil defoamer is used. Or silicone oil emulsion defoamer, which can solve the above problems satisfactorily. For another example, in the production process of polyvinyl chloride (PVC) flooring, etc., a layer of PVC sol film needs to be coated. To improve the surface wear resistance, there are dense bubbles in the PVC sol. If not eliminated, the transparency and appearance of the coating will be affected. When 0.2% (mass fraction) (based on PVC) modified silicone oil defoaming agent is added, the speed of vacuum degassing of the sol can be accelerated, the viscosity of the sol liquid can be reduced, and the workability can be improved. The surface of the cured sol film is smooth and smooth. bubble.
