| 摘要 |
<p>The invention comprises composite pigment particles having a silica core and a coating of copper oxide, the silica being within the range of from 25 to 75% by weight of the composite particles and the particles of silica being within the size range of from 1 to 20 microns and having an average size of from 5 to 10 microns. The copper oxide may be substantially cuprous oxide. The pigment may be prepared by mixing silica particles of the appropriate size range with a copper salt of an acid which forms a water-soluble salt with caustic alkali, e.g. CuSO4, and ions of a hydroxy acid, e.g. citric acid, treating the mixture with caustic alkali to produce a pH of at least 8, adding a reducing agent, e.g. a reducing sugar, filtering the mixture to remove the caustic alkali salt from the filter cake, which is dried at a temperature not exceeding 200 DEG C. Paint formulations containing the pigment are given.ALSO:An antifouling paint comprises pigment particles having a silica core and a coating of copper oxide, the silica being present within the range of 25% to 75% by weight of the composite particles and the particles of silica being within the size range of from 1 to 20 microns and having an average size of from 5 to 10 microns. The said pigment may comprise from 30% to 100% of the per cent by weight of the pigment contained in the paint composition. A typical formulation comprises 53.7% pigment, containing 98.7% cuprous oxide coated silica- 41% Cu2O and 1.3% organophilic bentonite, and 46.3% vehicle, comprising 13.2% chlorinated biphenyl, 40.7% water white rosin, 3.3% pine oil, 42.3% volatile petroleum solvent, and 0.5% methanol.</p> |
