| 摘要 |
<p>The binder consists of two components: (1) a resin which is the condensn. prod. of urea, or a phenol-urea mixt., with formaldehyde and furfuryl alcohol or contains furfuryl alcohol and (2) a curing agent of tosylic acid, xylene sulphonic acid or a mineral acid wherein (1) contains 5-40 wt.% (based on total (1)) of a "wash oil" (naphthalene homologues).</p> |
