GB626645A - Improvements in or relating to methods of preparing an artificial resin and the improved artificial resin resulting therefrom - Google Patents

Abstract

Synthetic resins suitable for use alone or with other resins in impregnating or varnishing compositions or after inclusion of fillers such as wood flour or asbestos for moulding, are prepared by heating with or without a catalyst, but preferably with an acid catalyst, furfuryl alcohol with dimethylol urea or dimethylolthiourea, either or both of the reactants being partially resinified if desired. The condensation products may be modified with aldehydes such as formaldehyde, benzaldehyde, acetaldehyde or crotonaldehyde and furfural, phenols, cresols, ketones, sulphamides, aromatic amides and amines, furamide. These substances may be added to the initial reaction mixture or to an intermediate condensate. Intermediate condensates may also be mixed with phenol-aldehyde, or urea-aldehyde resins. The products may be hardened by heat alone or in the presence of catalysts such as maleic anhydride, phosphoric acid, aniline hydrochloride, formic acid, oxalic acid, acetic acid. In the examples, dimethylol urea is heated with furfuryl alcohol (1) in the presence of dilute phosphoric acid, (2) in the absence of a catalyst, (3) in the presence of dilute phosphoric acid, (4) in the presence of maleic anhydride, (5) in the presence of dilute phosphoric acid and (6) in the presence of dilute phosphoric acid and with added formaldehyde. In example (1), the product dissolved in aqueous acetone and mixed with maleic anhydride was used for impregnating sheets of paper from which laminated board was prepared. The intermediate products are also soluble in aqueous methanol or dioxane. Specification 587,350 is referred to.