The use of polyhydroxy compounds for protecting substrates from corrosion, articles and methods for protecting substrates using these compounds and substrates so protected.

摘要

Metal substrates such as pipes and pipelines are often protected from corrosion by providing the substrate with a protective cover that is bonded to the substrate by. means of a sealant. In addition, a cathodic potential may be applied to the substrate to prevent loss of ions from the substrate due to electrochemical reactions. This can, however, lead to disbonding of the cover by a phenomenon known as "cathodic disbonding".

Cathodic disbonding may be reduced according to the invention by incorporation in the sealant at least 0.01 %, preferably at least 0.1% by weight of an organic, non-phenolic polyhydroxy compound, for example a mono- or polysaccharide, a synthetic hydroxy-containing polymer or a polyhydric alcohol. The sealant may be provided as a precoated layer on a cover for the substrate, preferably on a dimensionally heat-recoverable cover.