摘要 |
<p>Material comprises 90 to 99% wt. of a mineral pref. sand of particle size below 3 mm. more pref. below 1 mm. preferably a mixture of different sized particles, and 10 - 1% wt. of a phenol/aldehyde resin, e.g. of a cresol and an acetaldehyde, butyraldehyde or furfural, optionally there is present as reinforcement mineral asbestos, glass synthetic or vegetable fibres, or metal bars, fibres or mats.</p> |