IPDI Trimer

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The CAS number for IPDI trimer is 67873-91-0, and the EINECS number is 267-445-2. IPDI trimer belongs to the IPDI homopolymer family. The CAS number for IPDI homopolymer (Isophorone diisocyanate homopolymer) is 53880-05-0, and the EINECS number is 500-125-5.

Structural Formula:

Physicochemical Properties

Solvent-free IPDI trimer is a solid. IPDI trimer products generally have a solid content of 70%, appearing as a light yellow transparent liquid with an NCO content of approximately 12%. Solvents can include butyl acetate, toluene, xylene, propylene glycol monomethyl ether acetate, and their mixtures.

Characteristics and Uses

IPDI trimer is a mixture of IPDI trimers and a small amount of oligomers. It contains isocyanate groups and is a cycloaliphatic polyisocyanate with an average functionality between 3 and 4. It is a non-yellowing polyisocyanate crosslinker. The reactivity of IPDI trimer is lower than that of linear aliphatic diisocyanates, resulting in slow curing at room temperature and a pot life of 24–72 hours. Dibutyltin dilaurate can be added to improve its reactivity, at a concentration of 0.01%–0.1% of the solid content.

IPDI trimer products have excellent solubility and are soluble in ketones, esters, aromatics, chlorinated hydrocarbons, and petroleum solvents. They are also miscible with most resins. It is mainly used as a crosslinker for hydroxyl-containing polyesters, acrylates, flexible medium-to-short oil or short-oil alkyd resins, and two-component polyurethane paints. When combined with suitable polyols, it yields coatings with excellent weather resistance and lightfastness (non-yellowing). Adding a portion of IPDI trimer to two-component polyurethane coatings based on linear aliphatic isocyanates can improve drying properties, surface hardness, pot life, and environmental corrosion resistance. IPDI solution products can be used as crosslinkers for waterborne polyurethanes. Typical application areas include automotive paints, marine coatings, metal topcoats, repair coatings, and non-yellowing adhesives.