| 摘要 |
A crushing part or component of a gyratory grinder or other crushing, grinding or material-reducing machine is provided with a shock-absorbing backing material which has improved flow properties at low ambient temperatures and is formed of a filled polyurethane resin composition derived from a cold-curing liquid system formed by mixing together (a) a liquid material comprising the polyol component and at least part of the filler in the composition and wherein the polyol component comprises (i) one or more polyether polyols each having at least two hydroxyl groups per molecule, the average number of hydroxyl groups per molecule being more than 2 but not more than 3.3, (ii) one or more polyols each having at least two hydroxyl groups per molecule and containing both ether and ester groups, the average number of hydroxyl groups per molecule being more than 2 but not more than 3.3, and (iii) at least one ester of a long chain hydroxylated fatty acid having at least 10 carbon atoms (including the carboxylic carbon atom); (i) and (ii) being present in amounts such that (i) provides from 1.5 to 3.5 hydroxy groups for each hydroxy group provided by (ii), and (iii) being present in an amount of 2 to 10% by weight of said liquid material, and (b) at least one aromatic polyisocyanate in an amount such that there is an excess of isocyanate groups over hydroxyl groups in the cold-curing system, and said liquid material also includes a quaternary ammonium smectite, as defined, in an amount of from 0.2% to 2% by weight of the liquid material. |
