RU2270752C1 - Method of production of antipyrine - Google Patents

Abstract

FIELD: methods of production of antipyrines for fireproof treatment of wood materials.

SUBSTANCE: proposed method includes interaction of carbamide formaldehyde concentrate of the following composition, mass-%: carbamide, 21-25; formaldehyde, 54-60; the remainder being water with ammonia water taken at equimolar ratio by formaldehyde and ammonia at heating in weak-alkaline medium in presence of aminoalcohol selected from group containing mono-ethanol amine, di-ethanol amine, tri-ethanol amine and amine modifying agent AM-1 added together with ammonia water in the amount of 0.01-0.3 mass-% in terms of carbamide formaldehyde concentrate followed by introduction of carbamide in the amount of 1-10 mass-% per 100 mass-% of carbamide formaldehyde concentrate; then, reaction mixture is cooled and neutralized with ortho-phosphoric acid to pH= 6.0-8.0.

EFFECT: optimization of synthesis process of antipyrines at retained fire resistance efficiency.

1 tbl, 2 ex

Description

The invention relates to a method for producing flame retardants for flame retardant treatment of wood materials and can be used in the woodworking industry, as well as in construction during preventive measures for fire protection of dry wood products.

Known [SU No. 517491, cl. In 27 K 3/52, In 29 J 5/00] a method of obtaining a fire retardant composition of the KM brand, mainly for processing wood fiber, obtained by fusion at 135-140 ° C 0.9-1.5 wt.h. urea and 0.8-1.2 wt.h. phosphoric acid, and urea is introduced in two doses - in the melt and at the stage of cooling and dissolution of the flame retardant in the amount of 55-70 and 30-45 wt.% of all urea, respectively.

A significant drawback of the resulting product is the formation of significant amounts of ammonia during the pressing of a fiberboard, which contributes to the gas contamination of production rooms, and the presence of excess urea causes a deterioration in the physical and mechanical properties of the slab products.

The closest in technical essence can be considered a method of obtaining a flame retardant composition described in [RU No. 2079403, class. In 27 K 3/52] by mixing an aqueous solution of phosphorus and nitrogen-containing flame retardant KM brand with aminoformaldehyde resin, potassium dichromate and polyacrylamide, and the reaction product 0.8-1.2 parts by weight is used as KM flame retardant phosphoric acid with 0.9-1.5 wt.h. urea in the melt, urea-formaldehyde resin is taken as the aminoformaldehyde resin, the impregnating aqueous solution contains 40-65 wt.% flame retardant, 0.1-0.3 wt.% polyacrylamide and 0.2-0.8 wt.% potassium dichromate, and the coating composition is 40 A 50% aqueous solution of urea-formaldehyde resin with the addition of 2.0-4.0 wt.% Flame retardant.

It should be noted that for this flame retardant composition the same disadvantages are characteristic as in the case of the above-mentioned flame retardant. In addition, the proposed composition is multicomponent and at elevated doses of amidophosphate is prone to premature curing of the impregnating layer, which significantly limits the scope of its practical application.

The objective of the present invention is to optimize the technology of obtaining flame retardant while maintaining a high level of its fire retardant efficiency.

This object is achieved in that the synthesis of the flame retardant is carried out by reacting a urea-containing compound with ammonia water when heated in a slightly alkaline medium in the presence of an amino alcohol, followed by condensation with urea, and neutralizing the reaction mixture with phosphoric acid to a pH of 6.0-8.0.

The essence of the proposed technical solution is a method of obtaining a flame retardant by reacting a urea-containing compound with ammonia water, taken in an equimolar ratio of formaldehyde in all forms and ammonia, when heated in a slightly alkaline medium in the presence of an amino alcohol, followed by injection and 1-10 wt.% Of urea in based on 100 wt.% urea-containing compounds and neutralization of the reaction mixture with phosphoric acid to a pH of 6.0-8, 0, while carbamide-containing compounds used carb midoformaldehyde concentrate composition, wt.%:

carbamide in all forms 21-25 formaldehyde in all forms 54-60 water rest

and as an amino alcohol, monoethanolamine, diethanolamine, triethanolamine, amine modifier AM-1 and other amino compounds added together with ammonia water in an amount of 0.01-0.30 wt.% calculated on urea-formaldehyde concentrate.

The chemistry of the processes is rather complicated and consists in the following. When heated, a urea-formaldehyde concentrate with ammonia, methyl urea, which are part of it, form a mixture of various amines (polyamine) [RU No. 2228925, cl. C 07 C 211/13, 209/60], and unreacted formaldehyde at the stage of pre-condensation is bound by urea to methyl urea and then to urea-formaldehyde resin. Upon subsequent neutralization of the polyamine with phosphoric acid, amidophosphate occurs. The amino alcohol present in its composition has a surface-active effect and improves the diffusion of the flame retardant deep into the wood and the wettability of its surface.

Under the influence of the impregnating solution, the carbon of lignin and other high molecular weight wood components under conditions of their ignition is carbonized and prevents the development of burning of unprotected wood. The use of a urea-formaldehyde concentrate with a high content of methylol groups as a urea-containing compound and the introduction of unbound urea at the stage of post-condensation contribute to the formation of a urea-formaldehyde resin that protects the flame retardant from leaching and weathering by forming a coating layer.

For this reason, the fire-retardant coating carries out its fire-retardant effect in the subsurface layer of wood and on the surface, thereby realizing the well-known mechanism of fire-retardant action in the condensed phase according to the theory of catalytic dehydration, and in the presence of insulation, according to the theory of the coating layer.

If necessary, the decorative properties of wood are directionally controlled by introducing colored compounds, for example, potassium dichromate, into the fire retardant composition.

The developed flame retardant composition provides for the use of cheap available components, which opens up wide opportunities for its use.

As a urea-formaldehyde concentrate, a product was used that meets the requirements of TU No. 2223-009-00206492-98.

The amine modifier AM-1, produced in accordance with TU No. 2423-017-00206492-2002, is the product of the conversion of oxazolidone-2 - a waste product of ammonia - into a mixture of amino alcohols, the main component of which is monoethanolamine.

It contains, wt.%:

monoethanolamine 15-70 a mixture of the products of the conversion of oxazolidone-2 to 1- (2-hydroxyethyl) imide-azolidone-2 and 1- (2oxyethyl) ethylenediamine, no more than 50 water rest.

The invention is illustrated by examples in the description and table.

Example 1

In a reactor with a volume of 5 m ³ load 1144 kg of ammonia water with a concentration of 27.7 wt.% And with vigorous stirring 1000 kg of urea-formaldehyde concentrate containing, wt.%:

carbamide in all forms 22.3 formaldehyde in all forms 56.0 water rest

and 1 kg of amine modifier AM-1. The addition of urea-formaldehyde concentrate is carried out at such a rate that the temperature of the reaction mixture does not exceed 60-65 ° C. After that, the contents of the apparatus are heated to 80-82 ° C and maintained at this temperature for one hour.

After that, the temperature of the resulting solution was reduced to 60-63 ° C and 43 kg of urea (4.3 wt.% Of the taken urea-formaldehyde concentrate) was introduced. The contents of the reactor are kept at this temperature for 30-40 minutes until the residual formaldehyde is completely bound, then the product is cooled to 22-25 ° C and neutralized with 77.6% orthophosphoric acid to a pH value of 6.9.

Example 2

The synthesis conditions of example 1.

As a urea-formaldehyde concentrate, a product containing, wt.%:

carbamide in all forms 25 formaldehyde in all forms 60 water rest

During the pre-condensation, 5.3 wt.% Of urea was added, calculated on the urea-formaldehyde concentrate, and instead of the amine modifier AM-1, triethanolamine was used in an amount of 0.5 kg.

The pH of the finished product was 6.7.

Evaluation of the fire-retardant effectiveness of anthypirene was carried out in accordance with NPB 251-98 "Fire-retardant compositions and substances for wood and materials based on it. General requirements. Test methods" on pine samples aged for 24 hours in the test solution at 20-22 ° C.

From the description of the invention and the table it can be seen that according to the claimed technical solution, it is possible to simplify the technology for producing a flame retardant, while maintaining a high level of fire retardant efficiency of a flame retardant with its reduced consumption for wood processing.

Table.
Properties of flame retardants according to the proposed method and prototype. Indicator Indicator value Prototype Examples one 2 Formaldehyde there is lack of pH - 6.9 6.7 Refractive index - 1,410 1,412 Density at 20 ° C, g / cm ³ - 1.17 1.18 Freezing temperature, ° С - minus 15 minus 16 Consumption for transferring wood into 1 group of fire-retardant efficiency, g / m ² 334-540 300 Mass loss during combustion according to NPB251-98,%. 4.7-7.9 5.2 4,5

Claims (1)

A method of obtaining flame retardants for flame retardant treatment of wood materials, characterized in that the method is carried out by reacting a urea-formaldehyde concentrate composition, wt.%: Urea 21-25 Formaldehyde 54-60 Water Rest with ammonia water taken in equimolar terms for formaldehyde and ammonia when heated in a slightly alkaline medium in the presence of an amino alcohol selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, amine modifier AM-1, added together with ammonia water in an amount of 0.01- 0.3 wt.% Based on urea-formaldehyde concentrate, followed by the introduction of 1-10 wt.% Urea per 100 wt.% Urea-formaldehyde concentrate, cooling and neutralizing the reaction mixture with phosphoric acid to a pH of 6.0-8.0.