CS221582B1 - Process for preparing a preservative - Google Patents

Abstract

The invention relates to a method for preparing a formaldehyde-based preservative for preserving feed. The preparation is prepared by reacting aqueous formaldehyde with ammonia or ammonium salts of organic or inorganic acids, optionally with the addition of organic or inorganic acids.

Description

The present invention relates to a process for the preparation of a preservative for the preservation of formaldehyde-based feedstuffs.

Formaldehyde-based preservatives form an important group and differ not only in their effectiveness but also in their preparation. The simplest formulation of this group is formed by mixing an aqueous solution of formaldehyde with an organic or inorganic acid with the necessity of using methanol as a stabilizing agent to prevent the formation of p-formaldehyde. This implies the need to handle methanol as a toxic substance with other adverse effects in terms of the formulation itself and the effect of the formulation.

The use of free formaldehyde for preservation is accompanied by its gradual binding to the amino acid nitrogen, with the consequent possibility of reducing the feed value of the preserved medium. The literature points to an increased risk of the transfer of residual formaldehyde to animal products, especially milk.

Another known substance in this group is hexamethylenetetramine with chemically bound formaldehyde with a bacteriostatic effect, explained by the progressive hydrolysis of hexamethylenetetramine. The method of its preparation is technologically sophisticated and its description is contained eg in the monograph: V. Ettel: Organic Technology I, pp. 398 - 399. Its preparation is based on an aqueous solution of ammonia and formaldehyde with an excess of the latter. The preparation is associated with the exothermic reaction, the need for heat removal, multi-stage vacuum evaporation, vacuum crystallization, drying and, last but not least, the generation of wastewater. As a result, the process is characterized by high energy consumption. In addition, in order to improve the function of the formulation, additional treatments are required, usually by mixing the hexamethylenetetramine thus obtained with the powdered or the hexamethylenetetramine thus obtained. crystalline sodium nitrite. This functionally satisfactory combination, however, entails the possibility of forming nitrosamines, at a lower pH of the preserved composition and hence a hygiene risk due to their mutagenic effect.

The above disadvantages are overcome by the process for preparing a preserved formaldehyde-based feed preservative composition according to the invention, which comprises treating an aqueous solution of 1 mol of formaldehyde with 0.2 to 2 moles of ammonia and / or ammonia in the form of an inorganic ammonium salt and / or an organic acid, optionally with the addition of 0.1 to 6 moles of inorganic and / or organic acid, wherein inorganic acid means sulfuric or phosphoric acid and organic formic, acetic, propionic, isobutyric, lactic, acrylic acid.

By this process, the nitrogenous bases or their salts in which the formaldehyde is bound to ammonia in the form of methylolamines, cyclic amine derivatives and derivatives thereof are obtained directly by the bactericidal and fungicidally active nitrogen bases. These compounds are all precursors of hexamethylenetetramine in its synthesis from ammonia and formaldehyde, respectively. products of its hydrolysis resulting in a complex equilibrium state according to the equation

2 (NH4) 2SO3 + 6HCHO

C6H12N4H2SO4 + H2SO4 + 6 H2O, expressing the use of ammonia in the form of ammonium sulphate, the composition of which depends on the nature and molar ratio of the use of the acid as ammonium salt and / or free acid and ammonia per mole of formaldehyde starting.

Depending on the reaction conditions of the molar ratio used, the nature of the acid used and the environment, the synthesis process and composition can be controlled within wide limits with respect to the intended uses.

Compared with the preparation of the prior art preservatives, in particular based on hexamethylenetetramine, the preparation process according to the invention represents a considerable simplification of the preparation process in terms of technology, resulting minimization of equipment requirements, the possibility of easy automation at low and high equipment capacities , at normal atmospheric pressure. This simplification consists in the direct synthesis of the active substances, some of which may arise when hexamethylenetetramine is used only during its hydrolysis.

Production of the preservative in this way is practically not associated with the generation of waste materials in the gas or liquid phase.

These facts are reflected in the efficiency of the whole production process, high yield, quality of the preparation, productivity of work with suitable liquid form of the preparation for further use.

In order that the invention may be more fully understood, the following examples are provided. Example 1

An aqueous preservative solution is prepared by mixing 880 g of a 30% aqueous ammonium sulfate solution and 486 g of 317% formalin to form free sulfuric acid. The resulting solution is stable indefinitely.

Example 2

An aqueous preservative solution containing sulfuric acid and organic acid was prepared in the same manner as in Example 1, and then 50 g of acetic acid, 50 g of isobutyric acid, 50 g of acrylic acid and 40 g of lactic acid were added.

Example 3

A phosphoric acid and surfactant preservative is prepared by mixing 150 ml of 37% formaldehyde and 400 ml of an aqueous phosphate solution of 19.3% primary ammonium phosphate and 9.1% secondary ammonium phosphate. After complete mixing, 1% stearic acid monoglyceride is added.

Example 4

A preservative containing sulfuric acid is prepared by mixing 880 g of a 30% aqueous ammonium sulfate solution containing 36 g of 25% aqueous ammonia and 486 g of 37% formaldehyde. Finally, 14 g of molasses is added.

Example 5

Preservative containing acid

Claims (1)

SUBJECT Process for preparing a preservative for the preservation of feeds based on formaldehyde, characterized in that an aqueous solution of 1 mole of formaldehyde is treated with 0.2 to 2 moles of ammonia and / or ammonia in the form of an ammonium salt of inorganic and / or organic sulfuric acid. The process is carried out by adding ammonia gas to 486 g of a 37% aqueous formaldehyde solution while cooling, and after adding 68 g of ammonia, 392 g of 50% sulfuric acid are slowly added under cooling. Example 1 a d 6 A formic acid preservative is prepared by mixing 486 g of 37% formaldehyde while cooling with 316 grams of primary ammonium carbonate and finally adding 500 g of formic acid. Example 7 A preservative containing sulfuric acid and propionic acid was prepared in the same manner as in Example 1. 1 and then 120 g of propionic acid was added. OF THE INVENTION acid, optionally with the addition of 0.1 to 6 moles of inorganic and / or organic acid, wherein inorganic acid means sulfuric or phosphoric acid and organic formic, acetic, propionic, isobutyric, lactic, acrylic acid.