Method of preparing bodies on the basis of urea-formaldehyde resins

Abstract

Abstract A METHOD OF PREPARING FOAMED BODIES ON THE BASIS OF UREA-FORMALDEHYDE RESINS. THIS IS ACCOMPLISHED BY FEEDING SEPARATELY AND CONTINUOUSLY A FIRST COMPONENT COMPRISING A NEUTRAL OR ALKALINE AQUEOUS SOLUTON OF A UREA-FORMALDHYDE PRECONDENSATE CONTAINING A SMALL ADDITION OF A SULFITE WASTE LIQUOR, AND A SECOND COMPONENT COMPRISING AN AQUEOUS SOLUTION OF AN ACID HARDENER SUCH AS PHOSPHORIC ACID, AND A FOAMING AGENT SUCH AS AN ALKYL ARYL SULFONATE, INTO A MIXING ZONE, INJECTING COMPRESSED AIR INTO THE RESULTING MIXTURE TO PROVIDE A FOAMED MASS, DISCHARGING THE MASS THROUGH A NOZZLE MEANS CONNECTED TO THE MIXING ZONE, AND ALLOWING THE MASS TO CURE. TO COMPENSATE FOR AN AFTER-SHRINKAGE IN CONNECTION WITH THE CURING, A SMALL AMOUNT OF CHALK IS ADDED TO THE AQUEOUT SOLUTION OF THE UREA-FORMALDEHYDE PRECONDENSATE. AN INCOMBUSTIBLE PRODUCT IS OBTAINED BY INCORPORATING INTO THE AQUEOUS SOLUTION OF THE UREA-FORMALDEHYDE PRECONDENSATE A MINOR AMOUNT OF COPPER PHTHALOCYANINE.

Inventors

• 👤 W Klug

Bibliographic Details