| Name | 4，4`-diphenylmethane diisocyanate(MDI) |
| CAS Number | 101-68-8 |
| EINECS Number | 202-966-0 |
| Molecular weight | 250.25 |
| Chemical formula | C15H10N2O2 |
| Melting point | 38-44 ℃ |
| Boiling point | 392 ℃ |
| Density | 1.19 g/cm³ |
| Appearance | White or light yellow powder |
Application
The primary products of this product are widely used in polyurethane coatings, in addition, they are also used in waterproof materials, sealing materials, pottery materials, etc.; the polyurethane foam made from this product is used as parts of heat preservation (cold), building materials, vehicles and ships; the refined products can be made into car block, buffers, synthetic leather, non-plastic polyurethane, polyurethane elastic fibers, non-plastic elastic fibers, films, adhesives, etc.
Production method
Diaminodiphenylmethane can be produced by reacting aniline with formaldehyde, condensing it in an acidic solution, neutralizing it with alkali and then distilling it, and then reacting it with carbonyl chloride to produce it, and then distilling it to refine it.
Other item
It contains an isocyanate group (-N=C=O) which reacts with the hydroxyl group in the paint or resin to cure during the synthesis of the resin or coating.
MDI is the general term for 4,4'diphenylmethane diisocyanate (pure MDI), mixtures containing a certain proportion of pure MDI and multi-phenyl multi-methylene polyisocyanate (polymeric MDI) and modifications of pure MDI and polymeric MDI, which are the most important raw materials for the production of polyurethane, with a small amount of MDI used in other applications apart from polyurethane. Polyurethane has the elasticity of rubber, the strength of plastic and excellent processing properties, especially in heat insulation, sound insulation, wear resistance, oil resistance and elasticity, etc. It is the sixth largest plastic after polyethylene, PVC, polypropylene, polystyrene and ABS (now it has surpassed ABS to become the fifth largest plastic), and has been widely used in national defence, aerospace, light industry, chemical industry, petroleum, textile, transportation, automotive, medical, and other industries. It has been widely used in national defense, aerospace, light industry, chemical industry, petroleum, textile, transportation, automobile, medical and other fields, becoming an indispensable new material for economic development and people's life.
MDI and TDI are substitutes for each other and are both raw materials for the production of polyurethane; MDI is slightly less expensive and less toxic than TDI, but is denser than TDI in the production of foam.