| 摘要 |
<p>2.1. Polyoxymethylene (polyacetal) is an excellent material from which, in particular, rigid articles can be produced in high accuracy. However, since polyoxymethylene is acid-sensitive, the object of the present invention is to provide a polyoxymethylene which has been stabilised towards acids. 2.2. By addition of from 0.01 to 5 parts of an alkali metal salt of a polybasic acid, for example oxalic acid or citric acid, and/or from 0.01 to 5 parts of a polyalkylene glycol, for example polyethylene glycol, and/or from 0.1 to 100 parts of a thermoplastic polyurethane, in each case based on 100 parts of a polyoxymethylene, the latter is stabilised against acid attack, where, in particular, the combination of an alkali metal salt, in particular of an oxalate, with a few parts of a thermoplastic polyurethane is advantageous. The weight loss of a stabilised POM can be less than 3% compared with non-stabilised POM on exposure to acid. 2.3. Areas of application in which the products are exposed to acidic agents, such as irrigation equipment, dishwashers and to the sanitary sector.</p> |
