| 摘要 |
A soap powder comprises soap, of which at least 50 per cent by weight is derived from unsaturated soap-forming acids, in admixture with sodium or potassium carbonate and disodium or dipotassium orthophosphate, the carbonate and orthophosphate being in such conditions that, when the powder is added to water, they dissolve before an appreciable amount of soap has dissolved. This ensures that these compounds react with the salts of hard water before the soap reacts therewith and is wasted. The unsaturated acids from which the unsaturated soap portion is derived may comprise rosin acids or unsaturated fatty acids containing a straight chain of at least 14 carbon atoms and liquid at 20 DEG C. The acids specified comprise oleic acid, linoleic acid, linolenic acid, palmitoleic acid, liquid unsaturated polymerized whale, fish and linseed oil fatty acids or rosin acids or mixtures thereof. Suitable oils for making the soaps comprise groundnut oil, sunflower seed oil, palm oil, linseed oil and rosin or mixtures thereof with more saturated oils, such as tallow and coconut oil. Preferably at least 60 per cent by weight of the soap constituent is derived from unsaturated soap-forming acids. The soap powders may contain 5-70 per cent of soap and preferably at least 20 per cent. To ensure that the carbonate dissolves before the soap, the carbonate may be added as separate particles to the soap particles, the particle size being within the usual range for soap powders; or the carbonate may coat the soap particles; or a molten mass of soap and carbonate may be sprayed together to form powder, the carbonate then dissolving in water at a greater rate than the soap particles. To ensure that the orthophosphate dissolves before the soap, it must be external to the soap, either as separate particles or as a coating on the soap particles. The proportions of carbonate and orthophosphate are at least 5 per cent and 8 per cent, respectively, by weight of the soap constituent. The upper limit of both compounds is 40 per cent by weight of the powder. Other adjuncts normally used in soap powders may be present, such as alkaline sodium silicate. |
