Addivion DEF 90A is a solvent-free wetting and dispersing additive based on a phosphoric acid ester, formulated at 100% active substance to wet inorganic fillers and inorganic pigments in filled, unsaturated polyester and epoxy systems where solvents need to be avoided. It is especially suited to low-emission SMC/BMC, LP and Class A formulations, LS formulations, and pultrusion processes, and also supports viscosity stabilization in filled BMC compounds.
Addivion DEF 90A Overview
Addivion DEF 90A belongs to the family of phosphoric acid ester wetting and dispersing additives, in which the acidic phosphate groups anchor onto the surface of inorganic fillers and pigments while the remainder of the molecule improves compatibility with the surrounding resin matrix. Because the product is 100% active substance and contains no solvent carrier, it is particularly well suited to low-emission and solvent-free processes where VOC content must be minimized.
The additive is recommended for use in SMC and BMC compounding, pultrusion, and epoxy resin systems, where reliable wetting of high filler loadings directly affects processing viscosity, surface finish, and mechanical properties of the cured part.
Composite formulators typically face a trade-off between filler loading and processability: higher filler content improves mechanical properties and cost efficiency, but also raises viscosity and increases the risk of poor filler wet-out unless an effective dispersant is used. Addivion DEF 90A is designed to address this trade-off directly by promoting rapid, thorough wetting even at the high filler loadings typical of SMC and BMC compounds.
Key Features
- Phosphoric acid ester chemistry: Addivion DEF 90A is a solvent-free wetting and dispersing additive built on a phosphoric acid ester.
- 100% active substance: The additive contains no solvent carrier, supporting low-emission and solvent-free formulation targets.
- Designed for inorganic fillers and pigments: The additive is optimized to wet and disperse mineral fillers commonly used in SMC, BMC, and pultrusion compounds.
- Viscosity stabilization in BMC: Beyond wetting, the additive helps stabilize viscosity over the maturation period typical of BMC compounds.
- Broad resin compatibility: The product performs across unsaturated polyester and epoxy resin systems, including epoxy-based adhesives and UV-curable systems.
Typical Applications
Addivion DEF 90A is primarily used as a wetting and dispersing additive in filled unsaturated polyester systems, where it is especially recommended for low-emission SMC and BMC, LP and Class A surface-finish formulations, LS (low shrink) formulations, and pultrusion processes. In each of these applications, effective filler wetting reduces processing viscosity and helps achieve a smooth, defect-free surface in the cured composite.
The additive is also recommended for epoxy resin systems, including epoxy-based adhesives and sealants and UV-curing systems, where it should be added before the solids for optimum performance. For complementary surface finish in the same filled unsaturated polyester and epoxy systems, formulators often evaluate Addivion SURF 35 alongside this grade.
Technical Specifications
- Composition: Phosphoric acid ester
- Acid value: 129 mg KOH/g
- Density (20°C): 1.16 g/ml
- Refractive index (20°C): 1.469
- Water content: 0.02%
- Active substance: 100%
- Function: Solvent-free wetting and dispersing additive for inorganic fillers
Phosphoric Acid Ester Wetting Mechanism in Filled Resin Systems
Phosphoric acid ester dispersants such as Addivion DEF 90A work through acid-base anchoring: the acidic phosphate groups interact strongly with basic or neutral sites on the surface of inorganic fillers such as calcium carbonate, alumina trihydrate, and glass fiber sizing, displacing air and moisture from the particle surface and allowing resin to wet the filler more completely. Because the additive is 100% active substance, the full dose contributes directly to filler wetting without diluting the formulation with solvent.
This mechanism is particularly valuable in high-filler-loading systems such as SMC and BMC, where poor wetting translates directly into higher compounding viscosity, longer mixing times, and surface defects such as pinholing or fiber show-through in the cured part. Because separation or turbidity may develop during storage, the product should always be warmed to 30-40°C and mixed well before use to restore uniform performance.
Storage Recommendations
- Store in the original, tightly sealed container, protected from moisture and extreme temperatures.
- Recommended storage temperature: 0-30°C.
- Separation or turbidity may occur during storage; warm to 30-40°C and mix well before use.
- Shelf life: Up to 60 months in the original, unopened packaging when stored under recommended conditions.
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 and professional use only
Formulation Guidance
Recommended addition levels are 0.5-1% of the additive, based upon fillers, for general wetting and dispersion, and 0.25-1% based upon resin when the goal is stabilizing viscosity in BMC compounds. For epoxy-based adhesives and sealants, 0.5-1% based on the filler is recommended. These levels serve as a starting point, with optimal dosage determined through a series of laboratory trials for the target system.
Addivion DEF 90A should be added to the resin mixture prior to homogenization and before the addition of fillers or pigments; in adhesive formulations, the additive should likewise be added before the solids for best results. For complementary air release performance in the same filled unsaturated polyester and epoxy resin systems, formulators may wish to evaluate Addivion SURF 53A.
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
Addivion DEF 90A: Safety & Handling
Addivion DEF 90A should be handled in accordance with standard industrial hygiene practices for resin and composite additives. 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. As with all wetting and dispersing additives, small-scale compatibility and dosage trials are recommended before full-batch formulation to confirm filler wetting performance and to check for any effect on viscosity, surface finish, or cure behavior in the target system.
Safety Data Sheet and destination-compliant labeling information for the product are available upon request. For related additive options, see also Addivion SURF 35 and Addivion SURF 53A.