| 摘要 |
<p>1. Binder based on thermosetting phenol-aldehyde resins with added thermoplastic materials, particularly for foundry purposes, characterised in that the phenol-aldehyde resin has a content of less than 1% by weight of free phenols and contains as an additive and soluble in petroleum hydrocarbons, a balsam colophonium in a quantity of 1 to 21% by weight, the percentages always being related to the total quantity of resin.</p> |
