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

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

Aliphatic Polyisocyanate (HDI Trimer) is a high-performance crosslinking agent functioning primarily as the hardener component in two-pack (2K) polyurethane systems. Characterized by its excellent weatherability, UV resistance, and chemical durability, it is widely utilized to crosslink polyol resins in premium automotive OEM, refinish, and heavy-duty industrial coatings. In the B2B chemical supply chain, this material is critical for coating manufacturers requiring non-yellowing performance and superior gloss retention in their final cured films. We supply this product as a clear, solvent-free liquid (100% active content), supported by moisture-protected industrial packaging and comprehensive technical documentation to ensure reliable formulation and long-term film performance.

  • CAS: 28182-81-2
  • Synonyms: HDI Trimer, Polymeric HDI, Hexamethylene Diisocyanate Homopolymer, Aliphatic Polyisocyanate
  • Einecs: 500-060-2
  • Molecular Formula: (C8H12N2O2)n
  • Grade: Industrial Grade / Coating Grade
  • Package: Available in moisture-sealed standard export steel drums
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Product Description

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.

FAQ - Technical & Supply Chain

Documents

Documents and Product Support

For product review and sourcing evaluation, supporting documents can be coordinated according to the product type, inquiry stage, and order requirements.

  • COA for batch-based quality reference
  • TDS for key physical and chemical information
  • SDS / MSDS for handling, storage, and safety reference
  • Packing information for sample, trial, and bulk orders
  • Technical communication based on application and specification requirements
Quotation

Information to Confirm Before Quotation

Clear sourcing information helps reduce specification mismatch and allows a more accurate quotation before sample or bulk order discussion.

  • Product name and CAS number
  • Application or intended end use
  • Required purity, grade, or specification
  • Sample quantity, trial order, or bulk demand
  • Preferred packing form or net weight
  • Destination country or port
  • Required documents or compliance expectations
Storage & Handling

Packaging, Storage, and Handling Notes

Packaging form, storage conditions, shelf life, and shipment arrangements should be confirmed according to the product characteristics, package size, and destination requirements.

Before order confirmation, buyers are advised to review the corresponding product documents and confirm whether any special storage, labeling, or handling requirements apply.

Supply Support

Sample, Bulk Order and Repeat Supply Support

Support can be arranged for sample discussion, bulk supply planning, packaging confirmation, and routine sourcing communication based on the actual product and order requirements.

For repeat-use formulations or long-term procurement plans, buyers may discuss specification consistency, packaging preferences, delivery expectations, and document coordination in advance.

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