| 摘要 |
<p>The invention consists in coating surfaces, which on occasion are in contact with concrete as it hardens, for example mould covers, concrete handling equipment etc., with a protective layer of plastic which has the property that concrete does not adhere to the plastic surface. The protective layer is made of a polymer pertaining to a certain group of polymers. This group is characterized by the fact that the polymer chains consist entirely or in large proportion - at least 30 per cent by weight - of an atomic group, which can be written: (I), where Qa, Qb and Qc each constitutes a single representive from the group hydrogen atoms, hydrocarbon groups and functional groups, but Qd constitutes a single representative only from the group alkyl groups. The most current ones in this group are polymetacrylates and polypropylene. The latter, especially, is highly suitable, owing to the fact that it is easy to produce thin films or fibres, respectively, thereof. The protective layer need not consist 100 % of a polymer according to the above definition but may consist of a mixture of such a polymer with another polymer compatible therewith, even one lacking the former's release capacity in respect of concrete as it hardens. The protective layer is applied to the surface to be protected by lacquering or by laminating with the aid of gluing or hot pressing. The protective layer, reinforced with fibres of the polymer type defined above, for example polypropylene fibres, is particularly wear-resistant.</p> |
