Resins derived from aldehyde and natural resins

Abstract

Abstract Synthetic resins are prepared by condensing, by heating under reflux conditions, the crude gum which exudes from coniferae (hereinafter referred to as "crude gum," and stated to contain resin acids and terpenes) with an aldehyde in the presence of a dicarboxylic acid or an anhydride thereof. Terpenes or spirits of turpentine may be added to the reaction mixture. The resins obtained may be neutralized with a metal oxide or an inorganic or organic alkali; or may be esterified with a mono- or poly-hydric alcohol; or may be modified by phenol-aldehyde resins. In examples: (1) turpentine is added to crude gum and the solution filtered, decanted, washed with aqueous oxalic acid solution and again decanted. The resultant crude gum solution is then condensed with aqueous formaldehyde in presence of oxalic acid and the resultant viscous resin diluted with white spirit or turpentine and cobalt naphthenate added. The viscous resin is (2) heated with slaked lime; (3) dissolved in turpentine and heated with slaked lime; (4) heated with a phenol formaldehyde resin and the product esterified with glycerine; (5) crude gum is filtered, turpentine added and the mixture heated with formaldehyde and oxalic acid; (6) crude gum is purified by the addition of turpentine, followed by filtration and is condensed with aqueous formaldehyde in presence of oxalic acid; (7) the crude gum solution of example (5) is condensed with paraformaldehyde in presence of oxalic acid; (8) the crude gum solution of example (5) is condensed with aqueous formaldehyde in presence of phthalic anhydride; (9) crude gum is condensed with formaldehyde in presence of oxalic acid.

Inventors

• 👤 Albert Canouet

Bibliographic Details