DOUBLE-LAYERED FRP PIPE WITH EXCELLENT HEAT RESISTANCE AND CORROSION RESISTANCE

摘要

PURPOSE:To improve the corrosion resistance at high temp. by making a corrosion- resistant layer of a fiber-reinforced plastic layer wherein a vinyl ester resin is mainly a matrix resin and making a reinforcing layer of a fiber-reinforced plastic layer wherein a specified resol-type phenol resin is a matrix resin. CONSTITUTION:The subject pipe has a corrosion-resistant layer and a reinforcing layer and the corrosion-resistant layer is a fiber-reinforced plastic layer wherein a resin contg. a vinyl ester resin as a main ingredient is a matrix resin and having a resin content of 50wt.% or more and the reinforcing layer is a fiber-reinforced plastic layer wherein a resol-type phenol resin obtd. by reacting a phenol raw material consisting of 0.2-0.9 pt. in terms of molar ratio of phenol and 0.8-0.1 pt. of one or two or more substd. phenol compd. of formula (I) (wherein R1, R3 and R5 means that one of them is a 1-9C alkyl group or a phenyl group and remaining two are each H; R2 and R4 are each H or a 1-9C alkyl) with an aldehyde in the presence of an alkaline catalyst is a matrix resin. In this case, the thickness of the corrosion-resistant layer is made about l/10-1/2 of the whole thickness of the FRP pipe and the remaining is made to be the reinforcing layer.