| 摘要 |
The present invention relates to synthetic resin-based systems, such as furan resins, to be used, in combination with suitable curing agents, as binders in mixtures with silica sand or other granular masses, for the production of foundry moulds and cores. In particular, one aim of the invention consists of the use of at least one alkyl ester of phosphorous acid and/or phosphoric acid and/or a salt thereof as an acidic catalyst for the manufacture of foundry binder mixtures, for example those of the 'no-bake' type. A further aim of the invention also consists of a mixture usable as a foundry binder, for example of the no-bake type, containing: a) monomeric furfuryl alcohol in quantities below 25% by weight of the mixture; b) formaldehyde in quantities no higher than 0.5% by weight of the mixture; c) at least one alkyl ester of phosphorous acid and/or phosphoric acid and/or a salt thereof. |
