Isonate M 304 Isocyanate Dow Chemical PU - Isocyanates >> MDI, diphenylmethane diisocyanate >> Modified MDI Modified MDI ISONATE* M 304 is a liquid MDI derivative ISONATE M 304 has been designed for use in the manufacture of semirigid moulded parts for sunvisors, dash-boards, arm rests and sound/ vibration dampening PU mats. Recommended MDI for the production of PU items which contain a continuous random woven glass mat (mat moulding). Liquid MDI derivative.