ACIDIC PHOSPHOROUS CONTAINING COMPLEX FORMING REAGENT AND METHOD OF OBTAINING IT (VERSIONS) Russian patent published in 2008 - IPC C07F9/38 E21B43/22 

FIELD: chemistry.

SUBSTANCE: the invention pertains to an acidic phosphorous containing reagent, is used in the oil industry, heat energy, textile industry, production of mineral fertilizers and household chemistry, and to methods of obtaining the reagent. The reagent (conventional name "АФК-1") contains the following in given mass %: acetoxyethylidenediphosphonic acid 50.0-95.0 mass %, acetic acid - 29.5-0.5 mass %, the rest is acetic anhydride to 100. The quantitative composition of the indicated reagent is determined by the method of obtaining it and the ratios of the initial reagents. The method of obtaining the reagent involves adding acetic anhydride to a suspension of acetic and phosphorous acid at temperature of 60-90°C for a period of 1.5 hours. The reaction mixture is kept at 100-110°C for 1 hour and acidic impurities are distilled off to a controlled volume of distillate. Similar methods are developed based on phosphorous containing wastes from production of acid chlorides of higher fatty acids. The wastes are treated with water or a water solution of acetic acid with subsequent separation of the organic layer of fatty acids, after which the residue, containing phosphorous acid, is treated with phosphorous tri-chloride and acetic anhydride at 115-130°C, and acidic impurities are distilled off to the controlled distillate volume.

EFFECT: simplification of the process of obtaining acidic phosphorous containing reagent and increase in its ecological safety with reduction of the quantity of wastes.

4 cl, 17 ex, 2 tbl