108results about "Phosphorous acid" patented technology

A process for the manufacture of an aqueous composition that is a combination of a fungicide and fertilizer comprising the following steps:(1) dissolving phosphorous acid in phosphoric acid to form a solution of an acid mixture;(2) reacting the acid mixture of step (1) with an aqueous potassium hydroxide solution at a temperature of about 65° C. to about 260° C. in a continuous reactor while maintaining the ratio of potassium to phosphorous in various mole ratios thereby forming a reaction mixture comprising potassium phosphates, potassium polyphosphates, potassium phosphites, and potassium polyphosphites and potassium phosphate phosphite copolymers; and,(3) cooling the reaction mixture rapidly at least 1° C. to 60° C., to below about 35° C. to about 65° C.Using a similar process a composition having fungicidal properties is prepared by reaction phosphoric acid with potassium hydroxide.The reaction mixtures prepared according to each of the above processes are also part of this invention.

The invention discloses crystalline aluminum phosphite, a preparation method thereof and application of the crystalline aluminum phosphite as or used for preparing a flame retardant or a flame-retardant synergist. The preparation method comprises the following steps: 1, reacting aluminum hydrogen phosphite and an aluminum-containing compound in water at 80-110 DEG C in the presence or absence of a small amount of strong acid to obtain a precipitate; 2, washing and filtering the precipitate; 3, drying the precipitate at the temperature of 100-130 DEG C to remove water; and 4, continuing to heat and dry the moisture solids at a low-speed gradient temperature rise speed of not more than 5 DEG C / min, and raising the temperature of the materials from normal temperature to not more than 350 DEG C within about 5-10 hours, wherein the temperature rise speed is not more than 5 DEG C / min. Compared with amorphous aluminum phosphite, the crystalline aluminum phosphite has higher thermal decomposition temperature, lower water absorption and weaker acidity, can achieve a synergistic effect with diethyl aluminum hypophosphite, has better flame retardant property, and is used as a halogen-free flame retardant component of a high polymer material.