摘要 |
1. A method of hardening furane resins by means of acid catalysts, characterised in that it consists in hardening the furane resin in the presence of a concentrated anhydrous solution of boric anhydride containing at least 5% by weight of boric anhydride, one or several organic solvents selected from mono- or polyalcohols, trialkylborates, formaldehyde diacetals and at least one acid selected from concentrated sulphuric acid and sulphonic acids having an aromatic nucleus, the solution being used at an amount of between 0.5 and 10% with respect to the quantity of furane resin to be hardened. |