| 摘要 |
<p>The invention relates to an organic binder used in foundry for correcting certain characteristics of the moulds and green-sand cores, respectively. According to the invention, the binder consists of the sodium salt of lower oligomers, trimers, tetramers and pentamers of the condensation product of the 1 and 2 naphthalene sulphonic acids with the formaldehyde, that can be used as an aqueous or anhydrous solution, in an amount of 0.012 ... 6%, in sodium silicate, with the module of 2.2 ... 2.5.</p> |
