UREA RESORCINOL FORMALDEHYDE ADHESIVES OF LOW RESORCINOL CONTENT

Low resorcinol content cold-setting urea-resorcinol-formaldehyde (URF) resins were prepared. Most of these adhesives had water-resistant pro perties, whereas some also presented weather- and boil-proof adhesive characteristics and performance. URF resins of acceptable adhesive per formance were also prepared by inducing branching by introducing a cer tain amount of resorcinol or of polyflavonoid mimosa tannin extract as a branching unit. Resorcinol content as low as 12.7 and 12.15% on tot al liquid resin were obtained by this method while still maintaining a dhesive performance and water-resistant properties.