1
William P Moore: Attrition resistant controlled release fertilizers. December 8, 1987: US04711659 (59 worldwide citation)

An attrition resistant controlled release fertilizer comprising: NH.sub.2 -containing water soluble central particles such as urea, surrounded and chemically bonded with a base coating, consisting of substituted ureas, formed by reacting a molecular excess of polyfunctional isocyanate with the NH.su ...


2
Donald C Young: Methods of producing concentrated urea-sulfuric acid reaction products. Union Oil Company of California, Dean Sandford, Gregory F Wirzbicki, Michael H Laird, May 1, 1984: US04445925 (57 worldwide citation)

Stable concentrated solutions of urea and sulfuric acid containing mono- and/or diurea sulfates and less than 35 weight percent water, free of sulfamic acid and/or ammonium sulfamate, are produced by a unique process that involves the simultaneous and separate addition of urea, sulfuric acid and opt ...


3
Donald C Young: Noncorrosive urea-sulfuric acid compositions. Union Oil Company of California, Dean Sandford, Gregory F Wirzbicki, Michael H Laird, September 6, 1983: US04402852 (54 worldwide citation)

Improved, liquid, urea-sulfuric acid reaction product compositions, noncorrosive to carbon steel, contain about 5 to about 75 weight percent urea, about 5 to about 85 weight percent sulfuric acid, 0 to about 75 weight percent water, and a corrosion inhibiting amount of certain dialkylthioureas, in w ...


4
James M O Donnell: Process for treating sewage sludge and fertilizer products thereof. Orgonics, Richard P Crowley, March 9, 1976: US03942970 (54 worldwide citation)

An apparatus for and a process of treating sludge filter cake and the granular product thereof which comprises reducing the particle size and moisture content of the sludge cake, sterilizing the sludge cake by contacting the sludge cake with an N-methylol-urea solution, reacting the N-methylol-urea ...


5
Donald C Young: Noncorrosive urea-sulfuric acid reaction products. Union Oil Company of California, Dean Sandford, Gregory F Wirzicki, Michael H Laird, September 13, 1983: US04404116 (53 worldwide citation)

Improved liquid, urea-sulfuric acid compositions noncorrosive to stainless steel contain about 5 to about 75 weight percent urea, about 5 to about 85 weight percent sulfuric acid, 0 to about 75 weight percent water and a corrosion inhibiting amount of a cupric ion-containing compound, in which the u ...


6
Donald C Young: Foliar fertilization method and composition. Union Oil Company of California, Dean Sandford, Michael H Laird, July 29, 1980: US04214888 (52 worldwide citation)

Aqueous urea solutions particularly suited for foliar fertilization are disclosed. They are characterized by low phytotoxicity, low corrosivity, and improved toxicity stability and comprise urea nitrogen and between about 0.005 and about 0.1 molar equivalents per mole of urea of a pH buffer having a ...


7
Jerry H Stoller, Harold A Hartung: High analysis liquid fertilizers. Stoller Enterprises, Kenneth H Johnson, February 16, 1982: US04315763 (51 worldwide citation)

High analysis liquid fertilizers comprising the reaction product of urea and phosphoric acid having a pH between 1.5 and 4 and optionally containing the reaction product of urea and sulfuric acid, various trace elements including those normally found as contaminants in wet process phosphoric acid, p ...


8
Alice P Hudson, Fred E Woodward deceased, by Louis Robinson legal representative: Controlled release fertilizers and methods of production. July 23, 1996: US05538531 (49 worldwide citation)

Controlled release, particulate fertilizer products having a water soluble fertilizer central mass encased in a plurality of water insoluble, abrasion resistant coatings plus unique coating compositions and methods for the production of such products are disclosed. At least one essential inner coati ...


9
William J Verdegaal, George F Verdegaal: Process for making liquid fertilizer. Verdegaal Bros Fertilizer, January 12, 1982: US04310343 (48 worldwide citation)

A new improved process for making liquid fertilizer having a high nitrogen and sulfur content has been developed in which urea and sulfuric acid are mixed. Exothermic heat, which normally builds up in successive reactions is dissipated via use of a non-reactive, nutritive heat sink, preferably compr ...


10
Donald C Young: Topical fertilization methods and compositions for use therein. Union Oil Company of California, Dean Sandford, Gregory F Wirzbicki, Michael H Laird, May 8, 1984: US04447253 (47 worldwide citation)

Improved liquid fertilizer compositions for applying urea to the soil surface contain urea-sulfuric acid reaction products having high H.sub.2 SO.sub.4 /urea molar ratios and are free of toxic components such as sulfamic acid normally associated with such products. The use of these compositions redu ...