Urea condensation compositions and methods of making the same

#The invention generally concerns urea-aldehyde condensation compositions, processes for preparing the same, and the use of the condensation compositions as fertilizers. The condensation compositions can be free of hot water insoluble nitrogen (HWIN).

#Urea-aldehyde condensates and polymers thereof are typically used in products ranging from slow-release fertilizers and feed for cattle to binders, resins, plastics, and insulating materials (Jahns et al. Journal of Polymers and the Environment (2003) 11:155; U.S. Pat. No. 9,340,495). Short chain urea-aldehyde condensates and polymers are especially valuable for use in fertilizers because of their water soluble nitrogen content.

#Conventionally, urea-aldehyde condensates are generated by the reaction of urea with formaldehyde and optionally a higher aldehyde (C2 and greater aldehyde) under acidic conditions and temperatures of greater than 50° C. to form urea-aldehyde condensate polymers (see U.S. Pat. Nos. 3,459,528; 4,298,512). The reaction is typically stopped by increasing the pH to approximately 7 to 8. When a higher aldehyde is used, molar ratios of formaldehyde to higher aldehyde are typically 9:1 to 1:3.

#Advantages of the present invention may become apparent to those skilled in the art with the benefit of the following detailed description and upon reference to the accompanying drawings.

#FIG. 1—is a representation of processes of the invention for producing urea-aldehyde condensates.

#FIGS. 2A and 2B—(A) is a representative HPLC chromatogram of methylene urea (MU) oligomers. (B) is the raw tabulated results from the representative chromatogram. MDU is monomethylenediurea; DMTU is dimethylenetriurea; TMTU is trimethylenetetraurea; TMPU is tetramethylenepentaurea.

#While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings. The drawings may not be to scale.

#The processes of making urea-aldehyde condensation compositions of the present invention provide an elegant solution to the problem associated with controlling the degree of polymerization of urea-aldehyde condensation products. Notably, the present invention provides for processes that allow for the production of urea-aldehyde condensation products where the majority of the nitrogen content in the products is cold water-soluble nitrogen. Further, the products can be free of hot water-insoluble nitrogen (HWIN). Without wishing to be bound by theory, it is believed that the reaction conditions, order of reactions, and/or order of reactants used to make the urea-aldehyde condensation products of the present invention allow for more efficient control of the degree of polymerization during the condensation reaction, which is believed to result in HWIN-free urea-aldehyde condensates.

#These and other non-limiting aspects of the present invention are discussed in further detail in the following sections with reference to the Figures.