Buffered amino alcohol solutions of N-(n-butyl)thiophosphoric triamide (NBPT) and urea fertilizers using such solutions as urease inhibitors
AssigneeWhitehurst Associates, Inc.
InventorsGarnett B. Whitehurst, Brooks M. Whitehurst
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Abstract
Reduced volatility of urea fertilizers are prepared in accordance with the present invention by first preparing an N-(n-butyl)-thiophosphoric triamide (NBPT) solution by dissolving NBPT in a mixture of an amino alcohol having the formula 1—(H)x—N—((CH2)m—OH)n where m is 1-3, x is 0 or 1, and n is 2 when x is 1 and 3 when x is 0: or the formula 2—(H)y—N—((CH2)—CHOH—CH3)z such that the length of the carbon chain where the secondary hydroxyl group is located is 3, y is 0 or 1, and z is 2 when y is 1 and 3 when y is 0, and a carboxylic acid having 6 or fewer carbon atoms. The solution is then combining with a urea fertilizer in granular or liquid form.
Claims18
A solution for use in reducing the volatility of urea fertilizers comprising N-(n-butyl)-thiophosphoric triamide (NBPT) dissolved in a buffered reaction mixture of an amino alcohol having the formula 1—(H)x—N—((CH2)m—OH)n where m is 1-3, x is 0 or 1, and n is 2 when x is 1 and 3 when x is 0 or the formula 2—(H)y—N—((CH2)—CHOH—CH3)z such that the length of the carbon chain where the secondary hydroxyl group is located is 3, y is 0 or 1, and z is 2 when y is 1 and 3 when y is 0, and a carboxylic acid having 6 or fewer carbon atoms to form an NBPT solution, said buffered reaction mixture containing the ammonium ion of said amino alcohol, the carboxylate ion of said carboxylic acid, and said amino alcohol, and having a pH of 8 to 10.
A solution for use in reducing the volatility of urea fertilizers comprising N-(n-butyl)-thiophosphoric triamide (NBPT) dissolved in a buffered reaction mixture of an amino alcohol selected from the group consisting of diethanolamine, dipropanolamine, triethanolamine, tripropanolamine, diisopropanolamine, triisopropanolamine, and mixtures thereof, and a carboxylic acid having 6 or fewer carbon atoms to form an NBPT solution, said buffered reaction mixture containing the ammonium ion of said amino alcohol, the carboxylate ion of said carboxylic acid, and said amino alcohol, and having a pH of 8 to 10.
A solution for use in reducing the volatility of urea fertilizers comprising N-(n-butyl)-thiophosphoric triamide (NBPT) dissolved in a buffered reaction mixture of an amino alcohol having the formula 1—(H)x—N—((CH2)m—OH)n where m is 1-3, x is 0 or 1, and n is 2 when x is 1 and 3 when x is 0 or the formula 2—(H)y—N—((CH2)—CHOH—CH3)z such that the length of the carbon chain where the secondary hydroxyl group is located is 3, y is 0 or 1, and z is 2 when y is 1 and 3 when y is 0, and a carboxylic acid having 6 or fewer carbon atoms selected from the group consisting of acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and mixtures thereof, to form an NBPT solution, said buffered reaction mixture containing the ammonium ion of said amino alcohol, the carboxylate ion of said carboxylic acid, and said amino alcohol, and having a pH of 8 to 10.
Dependencies are inferred from the claim text.