POLYMERIC COMPOSITION FOR INSULATING COATING Russian patent published in 1999 - IPC

FIELD: protection of main gas and petroleum product pipelines and other metallic structures from corrosion. SUBSTANCE: polymeric composition comprises the following components, ratios of components being as follows, wt %: high molecular butyl rubber, 40-42; petroleum softener, 7-8; oligomer 14-15; zinc oxide, 1.2-1.5; high density polyethylene, 2.3-2.7; industrial carbon, 0.3-0.5; phenol-type thermostabilizer, 0.04-0.06, and the mineral filler balance. Oligomers comprises, wt %: vinyl toluene, 20-35; dicyclopentadiene, 30-35; styrene, 6-10; indene, 7-10; non-identified inert components, 14-31. Mixture is stirred at 160-180 C for 9-10 min and bundle is formed, fed into calender to combine with film substrate from high- and low-density polyethylene with industrial carbon and thermostabilizer. Strength of adhesive joint with nonadhesive surface after 24 h under normal conditions is 4.8-5.3 H/cm, after immersion into water at 60 C is 3.8-4.3 H/cm, in the air at 60 C is 5.0- 5.6 H/cm. EFFECT: greater adhesion strength. 6 ex, 2 tbl