| 摘要 |
<p>This invention relates to a process of preparing aqueous slurries of vesiculated granules of crosslinked polyester resin wherein the granules have a maximum shrinkage on drying of 5% of the granule diameter. Previously-known processes for the preparation of granules of this type have utilised polyamines; this has led to odour and colour problems. These problems may be eliminated or substantially reduced by the use of bases which are metal oxides, hydroxides or salts wherein the metal cation is selected from Ca, Mg, Ba, Ti, Zn, Pb, Sr and Co and, when a metal salt is used, the pKa value of the conjugate acid of the anion is greater than 2. The resulting granules are useful as matting and opacifying agents in, fur example, paint compositions.</p> |
