[Background and Overview][1][2]
As a traditional anti-rust pigment, phosphate has been recognized by the coating industry for its anti-rust ability in solvent-based coatings and is the most important component of non-toxic anti-rust pigments. Phosphate is used as an anti-rust pigment in coatings. Its anti-corrosion mechanism is very complex. One mechanism is that the metal and phosphate ions of orthophosphate slowly react with the metal matrix to form a dense and firmly adherent phosphating layer. Film to prevent corrosive media from corroding the substrate. Research findings confirm that the zinc phosphate in the epoxy coating can react with the interface of the steel substrate to form a phosphating film containing FePO4. In addition to phosphating, phosphates can also react with carboxyl and hydroxyl groups in the coating, as well as certain ions in the corrosive medium, to form complexes that adhere closely to the surface of the substrate to form a protective film. Some studies have studied the corrosion inhibition effect of zinc phosphate and found that adding zinc phosphate to the epoxy coating greatly slowed down the corrosion rate of the metal substrate. Nano-zinc phosphate is added to the coating for phosphating, and the nanoparticles can improve the density of the coating. At present, there is little research on the corrosion resistance of barium phosphate, one of the types of phosphates, used in coatings.
Barium phosphateChemical formula Ba3(PO4)2. Molecular weight 601.96. White cubic crystal. Relative density 4.116. Soluble in acid, insoluble in water. Mainly used in pharmaceuticals, ceramics, construction, chemical materials and other fields.
[Application][3][4]
Barium phosphate is mainly used in the pharmaceutical and ceramic industries, construction industry, etc. Application examples are as follows:
1. Prepare a high-strength and lightweight building material. The high-strength lightweight building material includes the following components by weight: 6-13 parts of expanded perlite powder, 12-18 parts of clay, 5-9 parts of magnesium borate whiskers, 4-10 parts of glass beads, and 3 parts of calcium sulfate. -7 parts, barium phosphate 5-8 parts, methoxypolyethylene glycol 6-11 parts, polyacrylate emulsion 7-15 parts, urea-formaldehyde resin 5-10 parts, chlorosulfonated polyethylene 4-7 parts. As a preferred solution, the high-strength lightweight building material includes the following components by weight: 8-11 parts of expanded perlite powder, 14-16 parts of clay, 6-8 parts of magnesium borate whiskers, 5-8 parts of glass beads, 4-6 parts of calcium sulfate, 6-7 parts of barium phosphate, 7-10 parts of methoxypolyethylene glycol, 9-13 parts of polyacrylate emulsion, 6-9 parts of urea-formaldehyde resin, 5-6 parts of chlorosulfonated polyethylene. The preparation method includes the following steps:
S1: Take calcium sulfate and barium phosphate respectively, and grind the above two components in a ball mill. The speed of the ball mill is 40-90r/min. The ball-to-material ratio in the ball mill is 12:1-18:1. The ball milling time is 1.5-4h;
S2: Take 6-13 parts of expanded perlite powder, 12-18 parts of clay, 5-9 parts of magnesium borate whiskers, 4-10 parts of glass beads, 3-7 parts of calcium sulfate, and barium phosphate by weight. 5-8 parts, mechanically mix the above ingredients until evenly mixed;
S3: Put the powder evenly mixed in step S2 into the reaction kettle, heat the reaction kettle to a temperature of 80-95°C, and then put 6-11 parts of methoxypolyethylene glycol and polyacrylate into the reaction kettle. Mix 7-15 parts of emulsion, 5-10 parts of urea-formaldehyde resin, and 4-7 parts of chlorosulfonated polyethylene, and mix evenly;
S4: Hot-press the evenly mixed building materials from S3 in the mold. The hot-pressing temperature is 70-80°C and the hot-pressing time is 2-3h. After hot-pressing, cool to room temperature and let stand for 5-8h. Prepared as a high-strength lightweight building material.
2. Used to prepare an antibacterial, insecticidal and slow-release ecological agricultural and forestry fertilizer. The fertilizer is composed of the following components by mass: 22 to 26 parts of ammonium sulfate, 20 to 24 parts of potassium magnesium sulfate fertilizer, 20 to 24 parts of brown algae, 18 to 22 parts of cabbage, 20 to 24 parts of isatis root powder, and castor oil. 20 to 24 parts, 18 to 22 parts of silkworm excrement, 20 to 24 parts of Xanthium angustifolia, 20 to 24 parts of Cao Wu, 18 to 22 parts of gibberellins, 18 to 22 parts of paclobutrazol, 18 to 22 parts of alkyl glycosides, and glucose 20 to 24 parts of calcium phosphate, 18 to 22 parts of phosphorus pentoxide, 16 to 20 parts of barium phosphate powder, 20 to 24 parts of potassium tripolyphosphate, 18 to 22 parts of expanded vermiculite powder, 16 to 20 parts of cerium oxide powder, nitric acid 18 to 22 parts of lanthanum powder, 10 to 14 parts of fish meal, 10 to 14 parts of propoxur, 10 to 14 parts of monochloroacetic acid, 10 to 14 parts of pyrethrin, 10 to 14 parts of permethrin, and ferrous sulfate heptahydrate 10 to 14 parts, polymethyl methacrylate 10 to 14 parts, ammonia 10 to 14 parts, titanium tetrachloride 10 to 14 parts, sodium dodecyl benzene sulfonate 10 to 14 parts, N, N-dihydroxy 10 to 14 parts of ethylglycine. The preparation method steps are as follows:
1) Mix the stated mass parts of ammonium sulfate, potassium magnesium sulfate fertilizer, brown algae, cabbage, isatis root powder, castor oil, silkworm excrement, Xanthium sibiricum, Aconiflora, gibberellin, paclobutrazol, alkyl glycosides , calcium gluconate, phosphorus pentoxide, barium phosphate powder, potassium tripolyphosphate, expanded vermiculite powder, cerium oxide powder, lanthanum nitrate powder and fish meal are mixed, and dispersed by ultrasonic high-speed, the ultrasonic frequency is 20~40KHz, the dispersion speed is 5000~ About 5r/min, dispersion time is 30~60min;
2) Add the mass proportions of propoxur, monochloroacetic acid, acetomethane, permethrin, and ferrous sulfate heptahydrate, and disperse at high speed using ultrasound. The ultrasonic frequency is 20 to 35KHz, and the dispersion speed is 4800 to 5200r. /min, the dispersion time is 30~50min;
3) Add the specified mass parts of polymethylmethacrylate, ammonia, titanium tetrachloride, sodium dodecylbenzene sulfonate, N, N-dihydroxyethylglycine, ultrasonic high-speed dispersion, ultrasonic The frequency is 20~30KHz, and the dispersion speed is about 4600~4800r/min.The dispersing time is 20 to 40 minutes; this product can be obtained after mixing evenly.
【Preparation】[5]
1. Barium phosphate can be produced by the action of barium oxide and phosphoric acid, or by mixing barium hydrogen phosphate and barium carbonate and heating at 1000 to 1100°C for 10 to 15 hours.
2. A method for producing barium phosphate using a reactive extrusion process, including the following steps:
1) After mixing the soluble orthophosphate and the soluble barium salt, the mixture is reacted and extruded on a twin-screw extruder;
2) Aging the product of step 1) at 20-80°C for 4-48 hours to promote better crystal growth;
3) Wash, filter and dry the product of step 2) to obtain the barium phosphate.
[Main reference materials]
[1 Smooth opening agent] Compound Dictionary
[2] Sun Wei, Zhu Liwei, Liu Fuchun, Han Enhou, Ke Wei, Qian Zhouhai, &appadhesion promotermp; Jie Ganxin. (2016). Anti-corrosion mechanism of nanometer barium phosphate in epoxy coatings Research. Journal of Materials Research, 30(3), 192-198.
[3] Li Hui; Zhang Zhengya; Wang Xiugui; Zhao Kaixuan. A high-strength lightweight building material and its preparation method. CN201510310473.6, application date 2015-06-09
[4] Du Hui. An antibacterial and insecticidal slow-release ecological agricultural and forestry fertilizer. CN201611194055.6, application date 20161221
[5] Luo Hongbo; Ma Fangzhong; Zhen Lijun; Luo Zhangzhi; Liu Min; Gu Xiang. A method for producing barium phosphate using reaction extrusion technology. CN201410095075.2, application date 2014031
