Critical Chemicals / Isocyanates

TDI 80:20. PMDI. Pure MDI. Every isocyanate grade. Secondary allocation access when primary supply tightens.

Toluene diisocyanate and methylene diphenyl diisocyanate — the two reactive inputs for all polyurethane foam and rigid insulation production. Together, the isocyanate market consumes more than 11 million tonnes per year from five producers who control 88% of global TDI capacity and four producers who dominate MDI. We maintain secondary channel access for manufacturers facing allocation cuts, and provide supply market intelligence to framework agreement holders in advance of wider market awareness.

Discuss TDI/MDI access Grade specification guide Market intelligence

TDI allocation market: 5 producers control 88% of global capacity — spot market collapses during outages

When a world-scale TDI plant representing 15–20% of global capacity goes offline (unplanned outage, maintenance, feed disruption), the spot market ceases to function within 3–4 weeks. Producers allocate to contracted customers first — in full, at contract price. The remaining spot volume clears at whatever price the market will bear. For uncontracted buyers, that price is typically 40–80% above the pre-outage level, when any volume can be found at all.
Complete product specification — all TDI and MDI grades

Every grade, every key parameter, with test method and formulation significance

Product / Grade Key specification parameter Test method Specification limit Formulation significance Primary downstream application
TDI — Toluene Diisocyanate (Formula: CH₃C₆H₃(NCO)₂ · CAS 26471-62-5 · MW 174.16 g/mol)
TDI 80:20 Primary commercial grade NCO content ASTM D 5155 · ISO 14896 48.2–48.6% Determines stoichiometric polyol quantity — must be confirmed per batch for accurate index calculation Flexible PU foam: mattresses, furniture, automotive seating, carpet underlay, packaging foam
2,4-TDI isomer content GC · HPLC 79–81% Controls reaction rate and foam rise profile — 80% 2,4-isomer gives optimum slabstock rise time
2,6-TDI isomer content GC · HPLC 19–21% Higher 2,6 content accelerates gelation — carefully balanced for stable foam manufacturing window
Colour (APHA Hazen) ASTM D 5386 ≤20 APHA Pale yellow liquid at room temperature — darker colour indicates impurities or decomposition
Hydrolysable chloride ASTM D 5386 ≤100 ppm Excess Cl causes urethane catalyst poisoning and foam defects — critical parameter for amine-catalysed systems
Acidity (as HCl) Potentiometric titration ≤0.005% High acidity indicates phosgene residue — affects catalyst activity and worker safety
TDI 65:35 NCO content ASTM D 5155 48.2–48.6% Same NCO as 80:20 — stoichiometry identical; only reaction kinetics differ Coatings · Adhesives · Elastomers · CASE applications requiring slower gel time
2,4-TDI isomer content GC 64–66% Lower 2,4 ratio vs 80:20 — slower primary reaction, longer processing window for coatings and adhesives
Colour (APHA) ASTM D 5386 ≤30 APHA Slightly higher colour tolerance than 80:20 — acceptable for non-foam applications
Water content Karl Fischer ≤0.05% CRITICAL: water reacts with NCO groups to form CO₂, causing foam voiding and urea formation in coatings
TDI-100 (Pure 2,4-TDI) 2,4-TDI isomer purity GC ≥99.5% Highest reactivity, longest reaction window — used where maximum control over reaction sequence is required High-performance coatings · Specialty elastomers · Adhesives · Urethane prepolymers
NCO content ASTM D 5155 48.2–48.6% Same NCO total as mixed grades
Melting point DSC 19.5–21.5°C Pure 2,4-TDI is a solid below ~20°C — requires heated storage and transfer in cold climates
MDI — Methylene Diphenyl Diisocyanate (Formula: OCN-C₆H₄-CH₂-C₆H₄-NCO · Monomeric 4,4'-MDI CAS 101-68-8)
Pure MDI (4,4'-MDI) NCO content ASTM D 5155 33.0–33.6% Significantly lower NCO % than TDI — determines polyol ratio in TPU and rigid foam formulations Thermoplastic polyurethane (TPU) · Spandex/elastane fibre (Lycra) · Automotive adhesives · PU leather
4,4'-MDI isomer content HPLC ≥98.5% High 4,4' purity gives symmetrical molecule with high crystallinity — essential for TPU and elastomere hard segment
2,4'-MDI isomer HPLC ≤1.5% 2,4'-isomer disrupts crystallinity — excess gives softer, less well-defined TPU properties
Colour (Hazen) ASTM D 5386 ≤15 Hazen White crystalline solid at room temperature (mp ~40°C) — must be melted and maintained above 40°C for handling
Flash point ASTM D 93 >190°C High flash point — classified as combustible liquid, not flammable. Relevant for storage classification and insurance.
Polymeric MDI (PMDI) NCO content ASTM D 5155 30.5–32.5% Lower NCO than pure MDI — mixture of monomeric and oligomeric MDI species Rigid PU insulation (PIR/PUR boards) · Cold storage panels · Refrigerators/freezers · Spray foam insulation
Functionality (average f̄) NCO/chain end calculation 2.7–3.0 CRITICAL for rigid foam: higher functionality (vs TDI f̄=2.0) creates highly crosslinked rigid network. Closed-cell foam requires f̄ ≥2.7 for dimensional stability.
Viscosity at 25°C ISO 3219 (Rotational) 150–250 mPa·s Affects pumpability and mixing efficiency in foam machine. High-viscosity PMDI requires heated piping and equipment.
Appearance — Dark brown viscous liquid Dark colour from higher oligomers — does not affect foam properties. Not suitable for colour-sensitive applications (use Pure MDI).
Producer intelligence — who makes TDI and MDI, where, and how much

The global producer landscape — capacity, location, and supply risk by site

PRODUCER / GROUP COUNTRY TDI NAMEPLATE CAPACITY (KT/YR) MDI NAMEPLATE CAPACITY (KT/YR) KEY PRODUCTION SITES SUPPLY RISK NOTES
Wanhua Chemical China (PRC) ~1,470 · ≈40% global ~4,500 · ≈40% global Yantai · Ningbo · Fujian · Xinjiang · BorsodChem, Hungary World's largest TDI and MDI producer. Exceptional capacity concentration within one group creates significant supply, trade and geopolitical exposure.
Covestro Germany ~895 · ≈24% global ~1,770 · ≈16% global Shanghai · Dormagen · Baytown, TX Major global supplier. Shanghai TDI capacity increased from 310 to 370 kt/yr in 2026; European operations remain exposed to energy-cost and restructuring pressures.
BASF Germany ~540 · ≈15% global ~2,070 · ≈19% global Geismar, LA · Shanghai · Yeosu, South Korea Major integrated producer. European operations remain exposed to high energy costs; BASF's Ludwigshafen TDI complex has been closed.
Huntsman USA — ~1,370 · ≈12% global USA · Netherlands · China · other international sites Major global MDI producer with geographically diversified capacity, but still one of the industry's critical suppliers.
Dow / Sadara USA / Saudi Arabia ~200 · ≈5–6% global ~1,110 · ≈10% global Freeport, TX · Stade, Germany · Jubail, Saudi Arabia Major MDI supplier and important TDI producer through Sadara. Middle East production creates significant geopolitical and logistics exposure.
Kumho Mitsui Chemicals (KMCI) South Korea / Japan ~50 · ≈1% global* ~610 · ≈5–6% global Yeosu, South Korea Major Asian MDI supplier. MDI capacity reached 610 kt/yr; a further 100 kt/yr expansion is planned.
Hanwha Solutions South Korea ~150 · ≈4% global — Yeosu, South Korea Three-line, single-site TDI producer. Highly concentrated production footprint; approximately 90% of TDI output is exported.
Cangzhou Dahua China (PRC) ~150 · ≈4% global — Cangzhou, Hebei Significant Chinese TDI producer with approximately 150 kt/yr capacity.
Mitsui Chemicals Japan ~50 · ≈1–2% global* — Omuta, Japan TDI capacity has been reduced/optimized from the historical 120 kt/yr level; therefore the old 120 kt/yr figure should not be used as current capacity.
Tosoh Japan — ~470 · ≈4% global Shunan, Japan Important Japanese MDI supplier; smaller than the five dominant global producers but strategically relevant to Asian supply.
OCI South Korea ~50 · ≈1% global — Gunsan, South Korea Smaller TDI producer serving regional polyurethane markets.
Karoon Petrochemical Iran ~40 · ≈1% global ~40 · <1% global Bandar Imam, Iran Regional Middle Eastern supplier; geopolitical and sanctions-related trade/logistics risks can affect export availability.