Paint for heat detection, esp. in turbine generator - is based on organic resin with tetra:halogenated phthalamic acid, benzamide or phthalimide cpd. as tag

摘要

Paint compsn. for the detection of heat, for application to certain pts. of a turbine generator or similar equipment for detecting local overheating, consists of an organic resin coating compsn. (I), with a decomposition temp. below 250 deg. C, and 0.1-0.5 wt.% tag. The tag is a tetrahalogenated phthalamic acid (II), benzamide (III) or phthalimide (IV). (X is halogen. R and R1 are 1-23C alkyl gps. with a total of 12-24C, 6-20C cycloalkyl gps. and heterocyclic gps. with the divalent gp. attached to the N atom having the formula -(CH2)y-Q-(CH2)z-; Q is -O-, -S- or -SO2-; y and z are 1-23; y+z is 12-24. R2 and R3 are 1-23C alkyl gps. with a total of 12-24C or 6-20C cycloalkyl gps.). Pref. (I) is an epoxy or alkyd resin compsn. These tags have a chemical decompsn. temp. min 100 deg. C above the thermal decomposition temp. of (I) and can be detected at extremely low concns. by a gas chromatograph fitted with an electron capture detector or micro coulometric detector.