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Production of solid solutions of pesticides by short-term superheating and rapid drying

  • US 9,480,250 B2
  • Filed: 11/23/2007
  • Issued: 11/01/2016
  • Est. Priority Date: 12/01/2006
  • Status: Active Grant
First Claim
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1. A method for the production of pulverulent or granulated solid solution of a sparingly soluble pesticide, in which the sparingly soluble pesticide is molecularly dispersed in a matrix of inactive ingredients, comprisingpreparing a hot, pressurized aqueous solution of the pesticide and of the inactive ingredients of the matrix by heating an aqueous suspension of the sparingly soluble pesticide in the presence of the inactive ingredients of the matrix to temperatures that are above the boiling point at normal pressure and the sparingly soluble pesticide is dissolved, the temperatures during heating being in the range from 90°

  • C. to 300°

    C., andconverting the hot, pressurized aqueous solution of the sparingly soluble pesticide and of the inactive ingredients of the matrix to a solid form by spraying and drying, the temperature of the hot, pressurized aqueous solution before being fed into a spraying device being between 90°

    C. to 300°

    C., and the pressure of the aqueous solution before feed into the spraying device being from 1 to 15 MPa,where the aqueous suspension of the sparingly soluble pesticide in the presence of the inactive ingredients of the matrix is heated continuously in a devices such that the residence time of the solution containing the active substance at temperatures above 90°

    C. is less than 180 seconds and where the solution is led directly to a spraying device,where the pesticide is selected from the group consisting of insecticides, fungicides, herbicides and safeners and where the solubility of the pesticide at 20°

    C. is less than 1% by weight in water, 0.1 molar aqueous hydrochloric acid, aqueous phosphate buffer at pH 7.2, and 0.9 wt. % aqueous sodium chloride,and where the sparingly soluble pesticide molecularly dispersed in the matrix of inactive ingredients has a crystalline fraction less than 3 wt. %.

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