Application of Silicone Defoamer
1. Textile printing and dyeing:
(1) Sizing process: water-emulsion organosilicon defoamer, such as BD-304 (or organosilicon polyether), adding 0.2_0.25g/L in sizing tank
(2) chemical fiber oil agent: adding 0.02 - 0.04% water emulsion defoamer to chemical fiber oil. Silicone polyether silicone oil should be included in the formulation of chemical fiber oil.
(3) Desizing and refining: polyether-containing organosilicon, such as BD-3055, is selected.
(4) Bleaching: strong acidity, organosilicon defoamer.
(5) dyeing: silicone emulsion defoamer. Jet dyeing is best done with polyether organosilicon, high temperature defoaming, low temperature water-soluble and non-staining fabrics.
2. Petrochemical industry:
(1) drilling: ethyl silicone oil (or methyl silicone oil emulsion) for mud additives.
(2) Oil recovery: oil and gas separation, defoaming rod. The melting point is 2.8-13.9 degrees higher than the foam temperature at the wellhead.
(3) Natural gasoline absorption: dimethyl silicone oil is mixed into 2% solution with gasoline.
(4) Oil and gas separation demulsification:
A. Separation of oil and gas, adding 0.025-0.0065mg/kg to crude oil can improve production capacity.
B, demulsification: crude oil generally separated from micro emulsion W/O, adding 0.2mg/Kg suitable defoaming agent can achieve the effect of demulsification and defoaming.
(5) Refining: Vacuum distillation with defoamer improves the color of distillate, widens the range of distillate, and commonly uses diesel oil solution with silicone oil.
(6) High-energy fuels (internal combustion, jet and aviation fuels) are dispersed in kerosene with high flash point by cyanoalkyl polysiloxane, and then used as high-efficiency defoamer in high-energy fuels.
(7) Asphalt and residue: the amount of silicone oil added is 0.2 x 10-6-2.0 x 10-6.
(8) Delayed coking, De-Coking and scale removal: reference amount of defoamer: 0.05-100*10-6
(9) Defoaming drilling fluid: high-viscosity sulfonated metal salt (calcium petroleum sulfonate: sodium sulfonated asphalt = 1:1), the amount of siloxane added is about 100-400*10-6 or 5-15 mg/Kg, and sulfonate: siloxane close to 1:1 is the best.
(10) Lubricating oils, such as internal combustion engines, automotive lubricants, metal processing fluids, compressor oils, are added with silicone oil for defoaming because of the following advantages:
A, insoluble in lubricating oil, in a dispersed state, is conducive to adsorbing on the bubble film to break bubbles;
B. There are alkyl groups similar to mineral oils, which can squeeze into the vesicles and weaken the molecular gravity.
C. Low surface tension, good penetration, local surface tension is reduced when adsorbed on the surface of the vesicle, and bubbles are broken due to uneven surface tension of the vesicle.
Heavy oil is made of silicone oil with small viscosity and 1-10 *10-6 addition. In addition, alkyl polyacrylate is also better, with better gas release.
Branched chain amine is added to crude gasoline and naphtha, and then to lubricating oil. It can also be used as defoamer. The amount of branched chain amine is 0.05-1%. This defoamer can be added to metal cutting fluid.
3. Paper Industry
(1) pulping: silicone emulsion defoamer (90g/T paper).
(2) Coated paper: coated coatings, calendered paper for printing pictorials, etc., and non-silicon defoamer for coating bubbles.
(3) Sewage treatment: water emulsion organosilicon defoamer, such as BD-303 organosilicon defoamer.
4. Application of Coatings and Inks
I. Requirements for Defoamers in paint production:
(1) it has a certain affinity with the active material on the foam surface, but it should be insoluble and insoluble in the bubble liquid.
(2) The surface tension is lower than the surface tension of bubbles and has a lower HLB value.
(3) emulsion (latex) should be stabilized.
(4) Coatings can not cause adverse consequences of fish eye and shrinkage after film formation.
(5) Defoamer for waterborne coatings: The most insoluble substances in water, such as mineral oil, higher alcohols, silicone resin, silicone is the best defoamer for waterborne coatings.
Defoamer for non-waterborne coatings: commonly used substances that are difficult to dissolve in organic solvents, such as lower alcohols and organosilicon resins (organosilicon resins should be used in an appropriate amount, excessive shrinkage cracking, pitting, now mostly modified organosilicon resins or emulsified organosilicon resins).
II. Silicone defoamers recommended for use in waterborne coatings:
(1) The mixture of silicone oil and hydrophobic SiO 2 is suitable for: epoxy resin, casting, 0.3% dosage; thermoplastic acrylic resin, spraying, 0.3% dosage.
(2) The mixture of polyether polysiloxane and hydrophobic SiO 2 is suitable: thermosetting alkyd resin, dipping amount 0.3%, scraping amount 0.1%.
(3) The mixture of hydrophobic SiO 2, hydrocarbons and silicone oil is suitable for: thermoplastic acrylic resin, printing ink, 0.1% dosage; air-dried acrylic resin, casting, 0.5% dosage.
(4) silicone oil and hydrophobic SiO2 mixture emulsion is suitable for alkyd modified styrene acrylic resin, cast and 0.5%.
5. Silicone defoamer for detergent industry
Polysiloxane and modified sodium tripolyphosphate are used as powder detergent additives, and two methyl silicone oil (1500c.s) emulsion containing SiO2 2 to 6% is mixed with sodium polyphosphate. The amount of emulsion is 10 to 40%, forming hydrate as additive.
Metal cleaning fluids should be alkali-resistant, transparent and defoaming when liquid products are best added.
6. Silicone defoamers for food industry:
Food-specific polysiloxane resin: Dimethylpolysiloxane as the main body, containing less than 15% of SiO 2 food as aqueous solution, the emulsified products, other products can be directly used oil-based products, dosage control of less than 0.05g/kg, such defoaming occasions include fermentation and sugar production, silicon-glycol copolymer is suitable for the inhibition of foaming in fermentation process.
Conclusion: Although the foam in industrial production is small, the effect is not small. Choosing suitable defoamer can effectively reduce the effect of foam on production, improve production efficiency and ensure product quality. With the development of industry and technology, the development and application of organosilicon defoamers will penetrate into various industrial and chemical production fields.
Organic Silicon Forum Arrangement/Editor: Zhong Er