CS213474B1 - A method of preparing urea addition products with formaldehyde - Google Patents

Abstract

The method of preparation of addition products of urea with formaldehyde containing slowly multiplying nitrogen is characterized by the fact that it is allowed to react? uronium dihydrogen phosphate /C0/NH2//NH3+/H2P04“/ in solid crystalline form, in the form of an aqueous suspension, or in the form of an aqueous solution with formaldehyde, whereby for each mole of uronium dihydrogen phosphate in the reaction mixture, 0.3 to 1.5 moles, preferably 0.5 to 1.0 moles of formaldehyde are added, at a temperature of 10 to 95 °C and preferably 30 to 60 °C.

Description

213 474

BACKGROUND OF THE INVENTION The present invention relates to a process for the preparation of urea b addition products with formaldehyde containing slow nitrogen-forming reaction of uronic acid di-phosphate and formaldehyde.

The high solubility of classical nitrogen fertilizers can lead, in particular, to single nitrogen injections, and also to adverse environmental influences. For this reason, in recent years, in addition to the application of nitrogen fertilizers in the so-called split doses during the growing season, ways to increase the efficiency of nitrogen fertilization by using industrial fertilizers containing this basic in nutrient form in a gradual form are also sought. *

The classic type of nitrogen-containing slow-moving fertilizers is the addition of urea with aldehyde, of which urea-formaldehyde condensates are widespread. Many of the knowledge on the preparation of urea-formaldehyde condensates is summarized in R. Powell's "Controlled Release Pertilizers". Review No. 15, NDC / 3-75 /. The basis for the preparation of urea-formaldehyde condensates is the condensation reaction between urea and formaldehyde, which is catalyzed by the addition of acidic or alkaline reactants. catalysts use mineral acids such as H 2 SO 4, HCl, and H 3 PO 4 / Cs. aut.osv.č. 125 701, 135 890, 149 261, 171 721, 178 542, aut. osv. USSR No. 549 453,497 275; NSR pat. 2,405,355, 2,422,238; Me p. pat. 7,031,927; Ind.pat. 137, 253, Ps. J. Scient. and Industr. Res. D 21 63-64 (1962); Chimija in sel. chcz. 1964/2 //. Urea formaldehyde condensates are usually prepared by adjusting the pH of the pre-condensation urea / formaldehyde mixture by adding a catalyst, producing a product with a substantially lower solubility than the solubility to the reactants of the incoming components. , a crystalline precipitate of varying particle size (in addition to pH can also be controlled by adjusting the urea / formaldehyde ratio, reaction temperature, and water content of the system).

It has now been found that condensation products containing slow nitrogen can be prepared according to the invention by reacting uronium phosphate / CONHg / NRL3 / H2PO4 in a solid crystalline form, in the form of an aqueous suspension or in the form of an aqueous solution with formaldehyde, with Urea dihydrogen phosphate in the reaction mixture is 0.3 to 1.5 moles of formaldehyde, preferably 0.5 to 1.0 moles of formaldehyde, at a temperature of 10 to 95 ° C, preferably 30 to 60 ° C. In ... -

The process for preparing fertilizers according to the invention has several advantages compared to the dioposal processes, especially due to its simple, achieved reaction rate, high yield, undesirable effects on the quenching and physical properties of the reaction product.

The reaction product can be used directly as a mono-component nitrogen fertilizer, or as one of the sources of the dull component in the preparation of multi-component solid or suspension fertilizers. The invention is illustrated by, but not limited to, examples: Example 1, /

A sulfonation flask equipped with a high performance and control thermometer was submitted

Claims (1)

213,474,461.2 parts by weight of thermal phosphoric acid (85% H 2 PO 4) and batch-wise 216.2 parts by weight of crystalline urea with stirring. The resulting suspension was stirred for two hours and then allowed to cool to room temperature. The precipitated uronium dihydrogen phosphate containing 44.6% PgO ^ and ,27.2% amide nitrogen and 0.4% HgO was separated from the crystalline liquor by filtration. 103.1 parts by weight of a technical 36.84% aqueous solution of foraaldehyde were added to the 491.9 parts by weight crystallization of uronium phosphate dihydrogen phosphate. 113.5 parts by weight of urea-formaldehyde condensate were excluded in the form of amine amorphous or urea-formaldehyde condensate. microcrystalline precipitate containing 30.3% amidic nitrogen. The condensate is separated from the phosphoric acid solution by filtration. Example 2. From 302.0 parts by weight of the black phosphate extraction acid, containing 54.63% by weight P2 ° 5, θ, 499% Ρβ »0.310% Al 1 O , 11% Mg and from 185.1 parts by weight of urea crystals, 396.04 parts by weight of crystalline dihydrogen phosphate uranium were prepared. To 93 parts by weight of water, 200 parts by weight of uronium phosphate / 17.56% of amidic nitrogen, 44.8% were injected with constant stirring at 50 ° C and 103.1 parts by weight of technical phloral was added after dissolution. -dehyde. 129.5 parts by weight of urea-formaldehyde condensate containing 27.1% nitrogen were excluded. The resulting free-flowing product was separated from the green-colored phosphoric acid by filtration. PRS D Μ T T VYSÁLEZU 0.3 to 1.5 moles, preferably 0.5 to 1.0 moles, of formaldehyde are added per mole of formaldehyde solution for each mole of uronium phosphate in the reaction mixture, preferably 30 to 60 ° C at 10 to 95 ° C. Printed Moravian Printing Works, Operation 12, Leninova 21, Olomouc i C eji and: 2,40 Kčs