Polyvion ISO-A 75 is an aromatic polyisocyanate based on a toluene diisocyanate (TDI) and trimethylolpropane (TMP) adduct, supplied as a solvent-based solution at approximately 75% solids for two-component polyurethane coatings and adhesives. Formulated with an average functionality of roughly 2.7, it is designed to combine with a wide range of hydroxyl-functional resins to build durable, well-crosslinked films. The product is widely used across industrial coatings, anticorrosive coatings, and adhesive formulations where a versatile, general-purpose curing agent is required.
Polyvion ISO-A 75 Overview
Polyvion ISO-A 75 belongs to the family of TDI-TMP adducts, produced by reacting toluene diisocyanate monomer with the triol trimethylolpropane to build a higher-functionality curing agent from a low-molecular-weight aromatic isocyanate. This adduct architecture is one of the most established polyisocyanate hardener chemistries in the coatings and adhesives industry, valued for its broad compatibility and predictable crosslinking behavior across many different hydroxyl-functional binder systems.
Supplied at approximately 75% solids in solvent, the product is ready to use as the hardener component in two-component systems, requiring only combination with a suitable polyol or hydroxyl-functional resin and standard solvent letdown. Because the chemistry is aromatic, coatings and adhesives formulated with Polyvion ISO-A 75 are best suited to interior or non-UV-exposed applications rather than exterior substrates where long-term color stability is required.
Key Features
- TDI-TMP adduct chemistry: Polyvion ISO-A 75 is built on a well-established toluene diisocyanate and trimethylolpropane adduct structure, delivering reliable, predictable crosslinking performance.
- Broad resin compatibility: The product can be combined with a wide range of hydroxyl-functional resins, polyester polyols, and other hydroxyl-bearing substances to formulate two-component coatings and adhesives.
- Moderate functionality for balanced crosslink density: With an average functionality of approximately 2.7, the product builds a well-crosslinked film without the excessive brittleness sometimes associated with higher-functionality hardeners.
- Versatile across coatings and adhesives: Polyvion ISO-A 75 is suitable for both industrial coating systems and two-component adhesive formulations, simplifying supplier consolidation for multi-application users.
- High-solids solvent-based supply form: Supplied at approximately 75% solids, the product minimizes solvent load while remaining easy to handle and letdown for spray or roll application.
Typical Applications
Polyvion ISO-A 75 is primarily used as the hardener component in two-component polyurethane coatings for general industrial and anticorrosive applications, where its broad resin compatibility supports formulation flexibility across different polyol systems. Its established TDI-TMP adduct chemistry also makes it a reliable choice for two-component adhesive formulations bonding a variety of substrates.
Beyond industrial coatings and adhesives, the product is also applied in protective coating systems that prioritize dependable crosslinking and cost-effective performance over long-term outdoor color stability. For fast-drying wood and furniture coating applications, formulators often evaluate Polyvion ISO-M 14 alongside this grade to compare drying speed and sandability.
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 polyisocyanate (TDI-TMP adduct)
- Base chemistry: TDI/TMP adduct
- Supply form: Solvent-based solution, approximately 75% solids
- Average functionality: Approximately 2.7
- NCO content: To be confirmed based on the final specification sheet.
- Viscosity: To be confirmed based on the final specification sheet.
- Color: To be confirmed based on the final specification sheet.
- Function: Curing agent for two-component PU coatings and adhesives
TDI-TMP Adduct Chemistry
TDI-TMP adducts such as Polyvion ISO-A 75 are produced by reacting toluene diisocyanate with trimethylolpropane, a triol that provides three hydroxyl groups available to react with TDI monomer. The resulting adduct carries an average functionality above two, giving the cured film a denser crosslink network than a simple difunctional isocyanate while remaining far less complex to manufacture than isocyanurate trimer chemistry. This combination of moderate functionality, good reactivity, and broad compatibility has made TDI-TMP adducts a long-standing workhorse hardener across the coatings and adhesives industry.
Because the product is aromatic, it is not the preferred choice for coatings requiring long-term UV color stability; formulators targeting exterior or highly UV-exposed substrates should evaluate aliphatic HDI-based alternatives instead. As with all TDI-based hardeners, the product is moisture-sensitive and should be protected from humidity during storage and handling, since reaction with water generates carbon dioxide and can compromise film quality or adhesive bond strength.
Storage Recommendations
- Store in the original, tightly sealed container, protected from moisture, heat, and foreign material.
- Recommended storage temperature: 0-30°C.
- Storage at higher temperatures will increase color and viscosity over time.
- Shelf life: To be confirmed based on the final specification sheet.
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 with this curing agent, the NCO:OH stoichiometric ratio, choice of polyol or hydroxyl-functional resin, and catalyst package all influence pot life, cure speed, and final film or bond properties. Formulators are encouraged to run a small formulation matrix, adjusting stoichiometry and catalyst level, to identify the process window that delivers the target balance of hardness, flexibility, and adhesion for the intended application.
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 isocyanate hardeners, moisture exclusion during storage, mixing, and application is critical to achieving consistent film quality and adhesive performance.
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-A 75: Safety & Handling
Polyvion ISO-A 75 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 ISO-M 14 and Polyvion ISO TT350.