FIELD: chemistry.
SUBSTANCE: present invention relates to a coated substrate having a plurality of sections of syntactic polyurethane elastomer. In said elastomer, gas-filled microspheres are dispersed in a non-cellular polyurethane matrix, the sections are in contact with each other in one or more adhesive seams. Said substrate contains (a) a first section of a first syntactic polyurethane elastomer, at least on one part of the substrate and (b) a second section of a second syntactic polyurethane elastomer on at least one part of the substrate. Said sections are the reaction product of at least one polyetherpolyol, from 5 to 50 wt. % microspheres, 1-30 pts.wt chain extender with hydroxyl end groups per 100 pts.wt of polyether polyol, an aromatic polyisocyanate, a β-diketone compound and a catalyst containing at least 99.5 wt. % of zinc carboxylate. Reaction mixture is substantially free of mercury compounds. Said polyurethane matrix of the first and second elastomers has a morphology, characterised by the presence of separate morphological domains with a diameter of 0.1–3 mcm and substantially no other morphological domains with a diameter of 5–30 mcm. Said first section comes into contact with said second section with the formation of at least one adhesive joint, on which the first section is glued to the second section.
EFFECT: resulting elastomer is resistant to cracking and also adheres well to itself, which provides good bonding between the sections and makes it very useful as thermal insulation for underwater pipes and other structures with complex geometry.
7 cl, 8 dwg, 3 tbl, 2 ex
