Hot-melt adhesive for steel-plastic composite pipe

Abstract

The invention discloses a hot-melt adhesive for a steel-plastic composite pipe, which is prepared by blending and extruding the following components in percentage by weight by a parallel double screw extruder: 5-40% of binding resin master batch, 50-80% of polyolefin resin, 5-25% of tackifying resin and 0.02-5% of inorganic rare-earth oxide, wherein the binding resin is prepared by carrying out graft modification on polyethylene and / or ethylene copolymer, which is / are used as the matrix resin, and initiator (accounting for 0.01-0.2 wt% of the binding resin master batch) and unsaturated polar monomer (accounting for 0.1-5 wt% of the binding resin master batch); the polyolefin resin is used for adjusting the consumption of the binding resin master batch and the comprehensive properties of the hot-melt adhesive; and the tackifying resin is one or combination of SBS (styrene-butadiene-styrene), SEBS (styrene-ethylene-butadiene-styrene), SIS (styrene-isoprene-styrene), cis-1,4-polybutadiene rubber, nitrile-butadiene rubber and natural rubber. Since the rare-earth oxide is added, the grafting ratio of the binding resin master batch in the hot-melt adhesive is increased, thereby obviously enhancing the initial viscosity, enduring viscosity, binding strength and other properties.

Description

technical field [0001] The invention relates to a copolymer adhesive, specifically a hot-melt adhesive, especially a hot-melt adhesive for steel-plastic pipes. Background technique [0002] Steel-plastic composite pipe is a new type of pipe that has developed rapidly in recent years. It is based on steel pipe, steel strip or steel skeleton, and is compounded with various types of plastics (such as polypropylene, polyethylene, polyvinyl chloride, nylon, etc.). made. It takes advantage of the rigidity of metal and the chemical corrosion resistance of plastic, as well as the smooth inner wall of plastic pipes, less fouling, and small fluid resistance. Therefore, steel-plastic composite pipes have been widely used in industrial and agricultural production, daily life and urban construction. [0003] The steel-plastic composite pipe is composed of five layers, and its composition from inside to outside is: polyethylene / hot melt adhesive / steel pipe or steel strip / hot melt adhesi...

AI Technical Summary

Problems solved by technology

The Chinese patent with the publication number CN1323867A discloses a hot-melt adhesive modified by inorganic nanomaterials, which adds inorganic nanoparticles CaCO 3 、TiO 2 , talc or SiO 2 Increase the adsorption and lasting cohesion of the hot melt adhesive, make the aluminum pipe and polyethylene plastic effectively bonded, and obtain an aluminum-plastic pipe composite material with excellent performance; but if the above hot melt adhesive is applied to the steel-plastic pipe, there will be many problems. limitation

Due to the special working environment and use of steel-plastic pipes, there are higher requirements for the physical and mechanical properties, chemical resistance, aging resistance and processing performance of hot-melt adhesives: The bonding strength requirements of the melt adhesive are low. Steel-plastic composite pipes are mainly used in large-scale composite pipes such as municipal engineering and natural gas pipelines. The requirements for the bonding strength of hot-melt adhesives are relatively high; the connection method of steel-plastic composite pipes and aluminum-plastic pipes Different, the hot-melt adhesive of the above-mentioned patent has a low connection strength, so when it is used for steel-plastic composite pipes, the hot-melt adhesive is prone to cracking and falling off at the interface, thereby reducing the overall performance of the steel-plastic pipe

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