Abstract
Inordertostudytheeffectofcoaltarcomponentsonadhesionstrengthofheavy-dutyanticorrosivecoatingsformedwithtar-urethaneresinonsteelplates,polyurethanecoatingsthatwerecompoundedwith15kindsofpolycyclicaromaticcompoumdsasmodelcoaltarcomponentswereprepared.Afterthecoatingscompoundedwithnaphthalene,quinoline,2-naphtholandphenanthrenohavinggoodcompatibilitywithresinwerecuredonsteelplates,theadhesionstrengthofthecuredcoatingsintheordinarystateandthechangewithtimeundersalt-waterspraytestweremeasured.Thesystemcompoundedwithnaphthalene,2-naphthol,andphenanthrenowerefoundgoodpropertiesintheadhesionstrength・Howeveratthechangewithtimeundersalt-waterspraytest,onlythesystemcompoundedwith2-naphtholwasfoundtobegoodproperties.Inordertostudythemechanismofadhesiondurabilitywith2-naphthol,thecuredcoatingscompoundedwith2-naphtholandphenanthrenoasthereferenceweremeasuredtherelationshipbetweendynamicviscoelasticityandtemperature.Wefoundthattheshiftoftan6peaktowardlowtemperatureinthesystemcompoundedwith2-naphtholwasbiggerthanthatwithphenanthrene・Further,thedecreaseofstoragemodulusoftheformerwasbiggerandsharperthanthatofthelatter.Weconsideredthat2-naphtholaddedtosomeNCOgroupsinpolyisocyanateandhangedthecurednetworksystem,andthat2-naphtholresultedingoodplasticizingeffect・Inotherwords,theinnerstressinducedbycuringshrinkagewasstronglyrelaxedandthenadhesionpropertieswereimproved
