Production method for zinc undecylenate

Abstract

The invention discloses a production method for zinc undecylenate. The production method comprises the following steps: adding glacial acetic acid and zinc oxide into purified water, thereby preparing a zinc acetate aqueous solution; dropwise adding an undecylenate ethanol solution into the zinc acetate aqueous solution; heating, keeping the temperature at 40-80 DEG C, and reacting for 1-2 hours; and filtering, washing, crushing and drying, thereby obtaining a white or light yellow powder zinc undecylenate product.

Description

technical field [0001] The invention relates to a production method of zinc undecylenate, in particular to a production method of high-quality zinc undecylenate. Background technique [0002] Zinc undecylenate, pinyin name: Shiyixisuanxin, English name: Zinc Undecylenate, molecular formula C 22 h 38 o 4 , structural formula [CH 2 =CH(CH 2 ) 8 COO] 2 Zn, molecular weight 431.92. The melting point is 116-121°C. Properties: white or light yellow amorphous powder. Almost insoluble in water and ethanol. In case of strong acid, it can be decomposed into undecylenic acid and corresponding zinc salt. Uses: 1. Anionic surfactant; especially as a co-emulsifier for cream cosmetics; 2. It can also be used as an emulsifier and bactericide, such as a bactericide for various cosmetics and soaps. 3. Used in medicine, antifungal drugs, and treatment of skin diseases caused by fungi. [0003] [0004] For 10-undecylenic acid zinc salt. Contains C 22 h 38 o 4 Zn should be 98...

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Problems solved by technology

The weak point of its existence is: A, method (1) raw material zinc oxide is the white powder that is insoluble in water and ethanol, and this reaction is solid-liquid phase reaction, and the undecylenic acid zinc that generates is insoluble in ethanol and water. White powder, the reaction end point is difficult to control, the zinc undecylenate white powder generated during the reaction is often entrained and wrapped with more unreacted zinc oxide and undecylenic acid, which makes the reaction incomplete, and post-processing washing and drying are more difficult , the zinc undecylenate powder that obtains is coarser, and the finished product outward appearance is not uniform white fine and smooth, and the finished product is uneven in thickness, and there are some lumps, cause when making medicine and skin care cosmetics, drug distribution is uneven; B, method (2) The raw material used is zinc sulfate, and a certain amount of strong acid H is generated in the reaction process. 2 SO 4 , higher to requirement, and the sulfate in the product is on the high side, does not meet medicine or cosmetics quality standard; It is a liquid-liquid phase metathesis reaction in water, and the reaction is relatively complete, but because sodium hydroxide is used in the process, the post-treatment is more difficult, and the alkali metal and alkaline earth metal salt content in the obtained zinc undecylenate product exceeds the standard, and The melting point of the obtained product is only 115-116 °C, which is lower than the melting point of 116-121 °C in the pharmaceutical standard, and it is difficult to obtain zinc undecylenate products that meet the quality standards for medicine and cosmetics

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