Aliphatic Polyisocyanate (HDI Trimer) CAS 28182-81-2

Physicochemical Properties

Property	Typical Value
Appearance	Clear to slightly yellowish liquid
NCO Content	21.8 ± 0.3 %
Non-Volatile Matter	100% (Solvent-free)
Color (Hazen / APHA)	< 40
Viscosity (at 25°C)	2500 – 3500 mPa·s
Monomeric HDI Content	< 0.15 %
Density (at 25°C)	~ 1.16 g/cm³
Flash Point	> 150°C

Typical Applications

• Automotive Refinish & OEM Coatings: Functions as the primary crosslinker for acrylic and polyester polyols, delivering exceptional exterior durability, high gloss, and scratch resistance required for automotive clearcoats and topcoats.
• Industrial Protective Finishes: Formulated into anti-corrosion and heavy-duty maintenance coatings where resistance to harsh chemicals, solvents, and mechanical abrasion is strictly mandated.
• High-Performance Adhesives: Utilized to upgrade the heat resistance, cohesive strength, and hydrolysis resistance of solvent-borne and certain waterborne adhesive systems.
• Plastic & Wood Coatings: Provides excellent flexibility and non-yellowing properties for premium architectural wood finishes and exterior plastic parts.

Packaging

As a highly moisture-sensitive chemical, this product is standardly packaged in 225kg closed-head steel drums or 20kg metal pails. All containers are blanketed with dry nitrogen prior to sealing to completely exclude ambient moisture and ensure product stability during transport. Packaging configurations are palletized and stretch-wrapped securely for international bulk shipping.

Storage

Store in a cool, dry, and well-ventilated indoor environment strictly between 0°C and 30°C. Polyisocyanates are highly reactive with water, including atmospheric humidity. Exposure to moisture will trigger the formation of carbon dioxide gas, which can lead to dangerous pressure build-up inside the container and irreversible viscosity increase (gelation). Containers must be kept tightly sealed immediately after partial extraction.

FAQ

• What is the primary advantage of an aliphatic crosslinker over an aromatic one?Unlike aromatic isocyanates (such as TDI or MDI), aliphatic polyisocyanates like HDI Trimer exhibit excellent UV stability, meaning coatings crosslinked with this product will not yellow or chalk when exposed to sunlight, making them ideal for exterior topcoats.
• Is this product supplied with solvents?This specific commercial grade is supplied as a 100% active, solvent-free liquid. It can be thinned with standard urethane-grade solvents (e.g., butyl acetate, PMA) during your manufacturing process, provided the solvents are strictly moisture-free (water content < 0.05%).
• What is the typical shelf life of this material?When stored properly in its original, unopened, and moisture-sealed containers at recommended temperatures, the standard shelf life is typically 6 to 9 months from the date of manufacture.
• Can you provide documentation and testing samples?Yes, we provide standard Technical Data Sheets (TDS), Safety Data Sheets (SDS), and Certificate of Analysis (COA) with bulk shipments, and can supply commercial samples for your R&D formulation testing.