High temperature resistant butyl pressure sensitive adhesive

3PE and heat-shrinkable belt repair structure is the first choice for the external anticorrosive coating of buried steel pipelines in China, which has been applied in China for nearly 20 years. With the passage of time, a considerable part of domestic oil and gas pipelines (including station yards) have entered middle and old age, and the corrosion protection layer of pipeline aging failure and the corrosion protection layer outside buried pipelines gradually increased. In recent years, more problems of 3PE corrosion protection layer stripping failure have been found, serious metal matrix and even corrosion, bringing hidden dangers to the safe and stable operation of pipeline oil and gas production.

Thermoplastic polypropylene or polyethylene cold-wrapped tape has general requirements for metal surface treatment and can be manually deducted, which is convenient for construction quality control. It is the most suitable material for field pipeline overhaul at present.

Polyethylene cold wrap adhesive usually uses asphalt-modified butyl pressure-sensitive adhesive as the adhesive layer and polyethylene as the surface layer. However, under the influence of heat and other factors, polyethylene cold-wrapped tape is easy to wrinkle and sag. The heat resistance, soil stress resistance, and shear resistance of asphalt-modified butyl pressure-sensitive adhesive are poor, which seriously affects the anti-corrosion service life of the cold-wrapped tape.

The preparation method of the high-temperature resistant butyl pressure sensitive adhesive is characterized in that it includes the following steps: 1) the butyl rubber, 7-100,000 molecular weight polyisobutene, and filler are put into the double roll open mixer for mixing, mixing evenly, the birth film; 2)

Add the viscosifying resin and SEBS into the kneader and stir, and gradually heat to 140-150℃, the viscosifying resin and SEBS melt and mix evenly, to obtain the mixture A; 3) Add 30,000-60,000 molecular weight polyisobutene to the mixture A obtained in step 2), further melt and stir at 140-150℃ to obtain mixture B; 4) To the mixture B obtained in step 3), add the mixed raw film of step 1) and the antioxidant in turn, stirring at 140-150℃ for 1 hour to obtain high-temperature butyl pressure-sensitive adhesive.