PROCESS FOR THE PREPARATION OF UREAFORMALDEHYDE CONCENTRATED SOLUTIONS HAVING A HIGH CONTENT OF METHYLENIC LINKAGES

Aqueous concentrated solutions of urea, formaldehyde and reaction products thereof, having a molar urea to formaldehyde ratio of 1:4 to 1:10 and obtained under alkaline conditions are subjected to acid treatment (pH\sF4) at a temperature between room temperature and 100 DEG C.; the product is subseq...

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Hauptverfasser:	ENRICO BONDI, ARMANDO LARCHER
Format:	Patent
Sprache:	eng
Schlagworte:	ACYCLIC OR CARBOCYCLIC COMPOUNDS CHEMISTRY COMPOSITIONS BASED THEREON MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS METALLURGY ORGANIC CHEMISTRY ORGANIC MACROMOLECULAR COMPOUNDS THEIR PREPARATION OR CHEMICAL WORKING-UP
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Beschreibung
Zusammenfassung:	Aqueous concentrated solutions of urea, formaldehyde and reaction products thereof, having a molar urea to formaldehyde ratio of 1:4 to 1:10 and obtained under alkaline conditions are subjected to acid treatment (pH\sF4) at a temperature between room temperature and 100 DEG C.; the product is subsequently neutralized (e.g. with CaCO3). Sulphuric acid may be used for the acid treatment. The process may be carried out in a batchwise or continuous manner. The product has a higher concentration of methylenic linkages derived from formaldehyde (e.g. 20-24%) than resins prepared under alkaline conditions.