A kind of preparation method of viscose fiber co-soluble hydroxy phosphorothioate flame retardant

Abstract

The invention discloses a preparation method of a viscose fiber co-soluble hydroxy phosphorothioate flame retardant, which belongs to the technical field of organic synthesis. The method uses neopentyl glycol and phosphorus trichloride as raw materials, uses an ice-salt bath to maintain the reaction temperature below 0 degrees Celsius, slowly adds triethylamine dropwise, and reacts at room temperature after the dropwise addition; continue to add erythritol and triethylamine. Ethylamine, heated to reflux. The product was neutralized to neutral with 10% sodium hydroxide solution, stirred and filtered at room temperature to obtain a solid, washed with cold water and absolute ethanol, and dried to obtain a white solid. The method prepares 1,4-bis(5,5-dimethyl-2-thiophospha-1,3-dioxane-2-oxyl)-2,3-butanediol under conventional conditions, The intermediate does not need to be separated and purified, the operation is safe and simple, and energy is saved. The starting material of the method is cheap, which is beneficial to reduce the production cost. The process is simple, the energy consumption is low, the operation is convenient, and the method is suitable for industrial scale production.

Description

technical field [0001] The invention relates to a viscose fiber co-soluble hydroxy phosphorothioate flame retardant: 1,4-bis(5,5-dimethyl-2-thiophospha-1,3-dioxane-2 The preparation method of -oxygen)-2,3-butanediol belongs to the technical field of organic synthesis. Background technique [0002] 1,4-bis(5,5-dimethyl-2-thiophospha-1,3-dioxane-2-oxyl)-2,3-butanediol is a flame retardant based on Sandoflame 5060 A viscose fiber co-soluble hydroxy phosphorothioate flame retardant designed, which is directly mixed with alkali cellulose during use, reacts with carbon disulfide to form xanthate, forms viscose, and is spun into acid to form viscose The glue fiber makes the flame retardant molecules and the viscose fiber molecules mix at the molecular level, so as to realize the high-efficiency flame retardancy of the viscose fiber. [0003] 1,4-bis(5,5-dimethyl-2-thiophospha-1,3-dioxane-2-oxyl)-2,3-butanediol molecular formula is C 14 h 28 o 8 P 2 S 2 , whose chemical formu...

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Problems solved by technology

[0017] The Sandoflame5060 viscose fiber flame retardant produced by the Swiss Sandoz Company, because the more the product is, the more difficult it is to stir, and mechanical stirring is required. However, the solvent is easy to evaporate along the gap under heating conditions, so it is necessary to continuously add solvent; Tokuyasu needs to first React with water to generate acid and then react with alcohols; Xingyi Wang’s reactant, phosphorus pentoxide, will agglomerate after a period of time, cannot fully react, and needs to be ground; Zhang Shengqiang’s preparation of DOPNP requires two steps to complete, and the reaction time is long , the economic benefit is not high; Denghui Wu reacted with excess phosphorus oxychloride in the first step, and heating caused the volatilization of phosphorus oxychloride, resulting in waste

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