Polyvion ISO TT350 is an aromatic polyisocyanate based on toluene diisocyanate (TDI) isocyanurate trimer chemistry, supplied as a solvent-based solution for fast-drying two-component polyurethane coatings. Formulated as a hardener component at approximately 50% solids, it is designed to deliver rapid cure and reliable crosslinking in general-purpose industrial coating systems. The product is widely used across metal, machinery, and equipment coatings where fast turnaround and dependable film performance are priorities.
Polyvion ISO TT350 Overview
Polyvion ISO TT350 belongs to the family of TDI-based isocyanurate trimer polyisocyanates, produced by cyclotrimerizing toluene diisocyanate monomer into a higher-functionality, ring-structured curing agent. Supplied as a colorless to pale yellow solution in butyl acetate, the product carries a relatively low residual monomeric TDI content, supporting safer handling compared with unreacted TDI monomer while retaining the fast reactivity aromatic isocyanates are known for.
Because the isocyanate is aromatic rather than aliphatic, coatings formulated with Polyvion ISO TT350 cure and dry quickly, making the product well suited to general industrial finishing lines where production speed is a priority over long-term outdoor color and gloss retention. The product is supplied ready to use as a solvent-based solution, simplifying incorporation into finished two-component formulations.
Key Features
- TDI-based isocyanurate trimer chemistry: Polyvion ISO TT350 is built on toluene diisocyanate trimer chemistry, delivering fast cure speed and reliable crosslinking in two-component systems.
- Fast-drying performance: The product is formulated to support rapid drying and early handling strength, helping formulators maximize throughput on industrial finishing lines.
- Low monomeric TDI content: Cyclotrimerization substantially reduces free TDI monomer relative to the parent diisocyanate, supporting safer handling and application.
- Broad solvent and resin compatibility: The product can be thinned with a range of esters, ketones, and aromatic hydrocarbons, and is compatible with aliphatic and aromatic polyisocyanates, polyester polyols, and polyacrylates.
- Reliable crosslinking for two-component systems: Polyvion ISO TT350 supports consistent film build and hardness development across a range of hydroxyl-functional resin systems.
Typical Applications
Polyvion ISO TT350 is primarily used as the hardener component in fast-drying two-component polyurethane coatings for industrial and protective finishing applications, where rapid cure supports high-throughput production. Its aromatic TDI trimer chemistry makes it particularly well suited to metal coatings and machinery or equipment finishes where speed and film hardness are more critical than long-term UV color stability.
Beyond general industrial coatings, the product is also applied in a broad range of protective coating systems requiring dependable two-component crosslinking. For lightfast aliphatic alternatives where outdoor color and gloss retention are required, formulators often evaluate Polyvion HDI-T 33 alongside this grade to compare weathering performance and cure speed.
Technical Specifications
The product is characterized by the following indicative technical parameters; confirmed values will be provided in the final product specification sheet.
- Chemical type: Aromatic toluene diisocyanate (TDI) isocyanurate trimer
- Base chemistry: TDI trimer
- Supply form: Solution in butyl acetate, approximately 50% solids
- NCO content: To be confirmed based on the final specification sheet.
- Viscosity: To be confirmed based on the final specification sheet.
- Monomeric TDI content: To be confirmed based on the final specification sheet.
- Color (Gardner): To be confirmed based on the final specification sheet.
- Function: Curing agent / hardener for fast-drying two-component PU coatings
TDI Isocyanurate Trimer Chemistry
TDI trimer curing agents such as Polyvion ISO TT350 are produced by catalytically cyclotrimerizing toluene diisocyanate monomer units into a stable isocyanurate ring structure bearing multiple reactive NCO groups. This higher-functionality architecture allows the cured film to build a dense crosslink network quickly once combined with a hydroxyl-functional resin, which is a key reason aromatic TDI trimers remain widely used where fast cure and hardness development outweigh the need for outdoor color stability.
Because the product is moisture-sensitive, it should be protected from humidity during storage and handling, since reaction with water generates carbon dioxide and can compromise film quality or cause gassing in closed containers. Only PU-grade solvents with low water content should be used for thinning, and the product is not recommended for dilution to lower solids content, as prolonged storage of over-thinned solutions can lead to turbidity or sedimentation.
Storage Recommendations
- Store in the original, tightly closed container, protected from moisture, heat, and foreign material.
- Storage at higher temperatures will increase color and viscosity over time; store in a cool, dry area.
- Shelf life: To be confirmed based on the final specification sheet.
- Protect from direct sunlight during storage and transport.
Documentation & Compliance
Each shipment of the product is supported by standard quality and compliance documentation to help customers manage incoming inspection, formulation approval, and downstream regulatory reporting.
- Certificate of Analysis (COA): Provided per batch
- Safety Data Sheet (SDS): Mandatory prior to handling
- Labels: Prepared in accordance with applicable regulations
- Industrial use only
Formulation Guidance
When formulating two-component coatings with this curing agent, the NCO:OH stoichiometric ratio, resin selection, and drying conditions all influence pot life, cure speed, and final film hardness. Formulators are encouraged to run a small formulation matrix, adjusting stoichiometry and solvent blend, to identify the process window that delivers the target balance of dry time and film performance for the intended substrate.
Because the product is supplied as a solvent-based solution, solvent selection at the letdown stage should favor PU-grade solvents free of reactive hydroxyl or amino groups and low in water content, to preserve pot stability and avoid premature gelation. As with all TDI-based hardeners, moisture exclusion during storage, mixing, and application is critical to achieving consistent film quality.
Packaging & Logistics
- Packaging: Approved industrial packaging
- MOQ: Subject to packaging configuration
- Lead time: Indicative lead time, to be confirmed upon order acceptance
- Incoterms: Quoted case by case
Polyvion ISO TT350: Safety & Handling
Polyvion ISO TT350 should be handled in accordance with standard industrial hygiene practices for aromatic polyisocyanate hardeners. Users are advised to review the Safety Data Sheet prior to handling and to implement appropriate personal protective equipment and engineering controls as specified therein, since isocyanate vapors and mist can present respiratory and skin sensitization hazards if ventilation is inadequate. As with all curing agents, small-scale compatibility and cure trials are recommended before full-batch formulation to confirm performance in the target system.
Safety Data Sheet and destination-compliant labeling information for the product are available upon request. For related curing agent options, see also Polyvion HDI-T 33 and Polyvion ISO-M 31.