iso 5280-1979 xylene for industrial use specification《工业用二 m-xylene-d10 98.5% 5 star office permanent marker xylene/toluene-free smear proof 2,5-bis(chloromethyl)-p-xylene, 98% - cas 6298-72-2 - formula xylene from 2,5-dimethylfuran and acrylic acid using zeolite in