Method and composition for stabilizing soil and process for making the same

A multipurpose soil stabilizing and conditioning composition prepared by a process which includes the following steps:

• (a) forming a polymeric solution by adding a urea-melamine resin to an aqueous formaldehyde solution having a concentration from about 30-50% at a temperature of between 70.degree.-90.degree. C. and a pH of about 10 to 12 so that the molar ratio of formaldehyde to urea-melamine is in the range of 2.5:1 to 4.5:1 and mixing until all of the urea-melamine resin dissolves;
• (b) adding an alkali metal sulfite, bisulfite or metabisulfite to the polymeric solution of paragraph (a) to provide a molar ratio of sulfite group to the urea-melamine in the range of 0.8:1 to 1.2:1 and maintaining the resulting solution temperature at about 70.degree. C. to 90.degree. C. for a period of 20 to 180 minutes;
• (c) adding an inorganic acid to the solution from step (b) to thereby adjust the pH of the resulting solution to about 2.5 to 4.0 and allowing the reactants to polymerize for a period of 30 to 150 minutes;
• (d) adjusting the pH of the polymerized solution from step (c) to about 7-9 by adding an alkali metal hydroxide and maintaining the solution temperature at between 70.degree.-90.degree. C., for about 30 to 150 minutes to thereby form a component;
• (e) forming a urea-formaldehyde condensate by adding urea to water and heating up the solution to about 70.degree.-90.degree. C. and adjusting the pH to 8-10 by the addition of an alkali metal hydroxide;
• (f) forming an aqueous formaldehyde solution having a concentration from about 30-50% and adding the aqueous formaldehyde solution to the solution from (e) so that the amount of urea to formaldehyde is 1:5 to 1:6 to thereby drop the pH to 5 to 6 and then adjusting the pH to 8-9 by the addition of an alkali metal hydroxide and heating the resulting solution for 25-45 minutes to bring the temperature to between 70.degree.-90.degree. C. and the pH within the range of 7-8;
• (g) dropping the pH of the reaction solution obtained in (f) to between 4 and 5 by the addition of an inorganic acid, allowing the reaction to continue for 25-45 minutes and then neutralizing the solution by adding an alkali metal hydroxide and thereafter adding an amount of urea in an amount such that the overall molar ratio of urea to formaldehyde is 1:2 to 1:3 and allowing the pH of the solution to reach between 6 and 7 while the temperature is about 70.degree.-80.degree. C.;
• (h) adding formic acid to the solution of (g) to drop the pH to about 4-5 and allowing a reaction to continue from 20 to 60 minutes until the temperature is within the range of 95.degree. to 105.degree. C. and subsequently adding an alkali metal hydroxide to raise the pH to between 8 and 9;
• (i) adding the solution obtained in (h) to the solution obtained in (d) and adding a salt selected from the group consisting of di-sodium tetraborate, sodium chloride, potassium nitrate, phosphoric acid and potassium di-hydrogen orthophosphate, and mixtures thereof, to thereby form an intermediate composition having a ratio of urea-formaldehyde to sulfonated urea-melamine-formaldehyde of between 0.2:1 to 2.0:1;
• and wherein a solution produced herein has a solid content of between 20 and 45%;
• and
• (j) diluting the composition with water to a solid content of 1 to 15% to form the multipurpose soil stabilizing and conditioning composition.