DE487308C - Process for the production of condensation products from urea or its derivatives and formaldehyde - Google Patents

Description

Process for the production of condensation products from urea or its derivatives and formaldehyde It was found that the condensation of urea or its derivatives with formaldehyde in a significantly shorter time l, as this is possible by the known methods, if one the reaction, instead of, as before, at atmospheric pressure and temperatures of up to 100 °, at increased Pressure and temperatures above 100 ° can go on. There you have it, depending on the height. of the temperature used and the duration of the heating, perfectly in by hand, the water-soluble, water-insoluble or gelatinous condensation products to obtain.

The condensation can be both in the presence and in the absence of condensing agents, both in the case of a basic as well as neutral or acidic reaction be performed.

The products obtained can be used as paints and impregnating agents as well as for the production of hardened synthetic materials are used. The products can if desired, filler materials and dyes, elasticizing agents and the like are incorporated will. As fillers, both inert, such. B. wood pulp, cork flour, etc., as well as reactive substances, for example aldehyde curable substances, such as casein etc., or water-binding agents, such as. B. plaster of paris, cement and the like., Use Find. Instead of urea, thiourea or substitution products can also be used of urea, use its polymers instead of formaldehyde.

By working under pressure, i. H. in a closed vessel achieves that the condensation is significantly accelerated. So one must in order to be equal To reach condensation levels, in an open vessel for about 17 hours at boiling temperature condense, while in the closed vessel z. B. at 10 'the same effect is reached after about 3 hours. In general, it only works under pressure higher temperatures than the boiling point of the condensation solution to work. According to known physico-chemical laws, the temperature is higher the reaction accelerated considerably. Furthermore, when working in the open Inevitable losses of formaldehyde avoided in the vessel.

Example 1 i 600 parts of urea become 36.5 percent higher in i6 ¢ 5 parts neutralized formaldehyde solution dissolved. The whole thing is in the autoclave for 1 to 2 hours heated to 115 '. The pressure rises to 2 to 3 atmospheres. The condensation product is completely soluble in water. It can be further processed in the usual way. example e 600 parts of urea are dissolved in 16q.5 parts of 36.5 percent neutralized formaldehyde solution dissolved and in the autoclave 3 to 4 hours. heated to 1 to '. The condensation product. is a water-insoluble syrup.

Example 3 600 parts of urea become 36.5 percent more in 16q.5 parts neutralized formaldehyde solution and in the autoclave 3 to q: hours at 120 ° heated. The product is clear and gelatinized like a rubber.

EXAMPLE 60 parts of urea are dissolved in 175 parts of commercially available formaldehyde solution (34.2 percent) dissolved and 6 parts of hexamethylenetetramine were added. The solution will be 3 to 4 hours heated to 110 ° in the autoclave. The condensation product is a clear, firm, water-insoluble jelly.

Example 5 120 parts of urea become 36.5 percent higher in 329 parts Dissolved formaldehyde solution and added 2o parts by volume of ice: sig. The whole thing will be one hour heated to 107 ° under pressure. The product is a solid, water-insoluble jelly.

Claims (1)

PATENT CLAIM: Process for the preparation of condensation products from urea or its derivatives and formaldehyde, characterized in that the condensation is carried out in a liquid-dissolved state at elevated pressure and temperatures above too °.