Toluene 2,4-diisocyanate
CAS Number
584-84-9
EC Number
209-544-5
Abbreviation
TDI
What is Toluene 2,4-diisocyanate?
Toluene 2,4-diisocyanate (CAS 584-84-9), commonly abbreviated as TDI, is a reactive diisocyanate monomer used as a core building block in polyurethane synthesis.
Where is Toluene 2,4-diisocyanate used?
- Flexible polyurethane foam: primary isocyanate in manufacturing processes
- Automotive seating, furniture cushioning and mattress production
- Coatings and lacquers: crosslinker improving hardness, chemical resistance and adhesion, particularly effective on metal and wood surfaces
- Adhesives and sealants: TDI-based prepolymers for high-strength, flexible bonds in construction and automotive assembly
- Elastomers: TDI cures cast polyurethane parts requiring abrasion resistance, essential for industrial rollers and seals
- It reacts with polyols to form urethane linkages.
Commercial specifications
- Liquid, typically an 80/20 isomer blend of the 2,4- and 2,6-isomers (TDI-80)
- Pure 2,4-isomer (TDI-100) available for applications requiring controlled reactivity
- Purity typically 99% or above for technical-grade material
- Bulk supply in ISO tank containers and drums
Other Names (Synonyms)
Tolylene-2,4-diisocyanate|Toluylene-2,4-diisocyanate|toluene-2,4-diyl diisocyanate|Isocyanic acid, 4-methyl-m-phenylene ester|4-Methyl-m-phenylene diisocyanate|2,4-Tolylene diisocyanate|2,4-toluene diisocyanate|2,4-TDI|TDI
What are the physical properties of Toluene 2,4-diisocyanate?
Melting Point 19.5-21.5 °C
Boiling Point 251 °C @ Press: 760 Torr
Density 1.2244 g/cm³ @ Temp: 20 °C
Flash Point 250 °F
Appearance colourless to light yellow liquid
Color Colorless
Odor Sharp, pungent odor detectable at 0.02 to 0.4 ppm
Form Liquid
Water Solubility reacts
Vapor Pressure 0.03 mm Hg ( 25 °C)
Refractive Index n 20/D 1.568(lit.)
Log P 3.43 at 22℃
How is Toluene 2,4-diisocyanate classified and handled safely? Learn More
Danger
GHS06· Toxic GHS08· Health Hazard GHS05· Corrosive GHS07· Irritant
Hazard Statements
H315 Causes skin irritation
H317 May cause an allergic skin reaction
H318 Causes serious eye damage
H319 Causes serious eye irritation
Precautionary Statements
P203 Obtain, consult and follow expert instructions for use.
P233 Keep container tightly closed.
P260 Do not breathe dust/fume/gas/mist/vapours/spray.
P261 Avoid breathing dust/fume/gas/mist/vapours/spray.
Which trade and regulatory codes apply to Toluene 2,4-diisocyanate?
HS Code 29291010
UN Number 2078
ADR Class 6.1
Packing Group II
Storage Class 6.1A - Combustible acute toxic Cat. 1 and 2
very toxic hazardous materials
WGK (Germany) 2