Model Number: HMHT0033-18Melting point 64-68°C (lit.)rnDensity 1.8g/cm3(20℃)rnVapor pressure 2.68hPa(20°C)rnStorage conditions Storebelow+30°C.Solubility alcohol:sligChemicalbookhtly soluble(lit.)rnPH value 9.5-10.5 (100g/l, H2O, 20℃)rnCAS database 6035-47-8
Physical and chemical propertiesrn rnThis product is white crystal. soluble in water. Insoluble in absolute ethanol, ether and benzene. It has strong reducibility at high temperature. Has fading properties. Decomposition at high temperature produces toxic gases such as formaldehyde and hydrogen sulfide. In case of dilute acid, it decomposes, and its solution is neutral. Anhydrous melting point 63 ~ 64 ℃. Surface density 1.80 ~ 1.85 g/cm3. rnProduct Usagern rnThis product is used in the printing and dyeing industry as a whitening agent, reducing agent, bleaching agent and in the production of indigo dyes and vat dyes. It can also be used in the polymerization of synthetic rubber, sugar and vinyl compounds. rnProduction methodrn rnAdd 286 kg of zinc powder and 500 kg of water into the beating tank, and after pulping, add it to the shell-and-tube reactor, and absorb about 550 kg of SO2 to obtain zinc hydrosulfite (the reaction temperature is maintained at 40-45 °C, and the end point is pH value is 3 to 3.5).In addition, the formaldehyde of 698 kg 40% is added in the reactor, the above-mentioned zinc hydrosulfite aqueous solution is added dropwise under stirring, and gradually heat up, when the temperature rises to 95~100 ℃, add a total of 257 kg of zinc powder in batches, react under the insulation For several hours, the end point is less than 1% unreacted substance. The precipitate was left to stand, and the precipitate was transferred to a displacement kettle. After washing with clean water, 755 kg of 42% sodium hydroxide solution was added under stirring. The reaction was carried out at 65°C until the free base content reached 0.3% to 0.5%. The reactants were filtered to remove impurities, and the filtrate was clarified for 48 h and concentrated in vacuo. Cool to crystallize and pulverize to get the finished product.rn
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