AppliedProduct selection and comparison are drawn from the owner-authorized Coating Additives Handbook. Verify current TDS/SDS and performance in the intended formulation before use.
Technical challenge
Bond failure depends on the actual binder–substrate interface, pretreatment and cure, not a universal adhesion-promoter label.
Product selection
Candidates are organized by a supplied technical handbook and the individual published TDS where available. These are starting points for trials, not confirmed equivalents or universal dosage recommendations. Grades without a SITI TDS page are not treated as formally published product profiles.
| Grade / evidence | Relevant system | Selection considerations |
|---|---|---|
| ADDSiL 4007 ↗Published TDS profile · handbook slide 91, 92Products category ↗ | PU, epoxy and alkyd systems on inorganic substrates | Amino-functional silane; match functionality and hydrolysis conditions to binder and surface. |
| ADDSiL 4009 ↗Published TDS profile · handbook slide 91Products category ↗ | Epoxy, PU and acrylic coatings on glass, metal or ceramics | Epoxy-functional organosilicon option; confirm cure-system compatibility. |
| ADDSiL 4030 ↗Published TDS profile · handbook slide 91, 92Products category ↗ | Unsaturated polyester and UV/radiation-curable coatings | Methacrylate-functional silane; test on glass, metal or ceramic under actual cure. |
| KOBOND 4017 ↗Published TDS profile · handbook slide 94, 98Products category ↗ | Metal substrates in amino-bake and 2K PU coatings | Epoxy phosphate ester; evaluate metal adhesion after conditioning. |
| KOBOND 4019 ↗Published TDS profile · handbook slide 96, 98Products category ↗ | Solvent-borne primers and coatings on PP or other polyolefins | Modified chlorinated polypropylene; assess surface treatment, primer compatibility and durability. |
| KOBOND 4045 ↗Published TDS profile · handbook slide 94, 98Products category ↗ | UV-curable and unsaturated-resin systems on metals | Reactive phosphate ester; verify under the actual radiation cure and substrate preparation. |
| KOBOND 4063 ↗Published TDS profile · handbook slide 84, 94Products category ↗ | Melamine-bake and selected 2K PU coatings on metals | Acid-functional polyester; compare initial and conditioned adhesion in the target system. |
Adhesion-promoter starting matrix
The table reproduces product-selection directions from the owner-authorized handbook. Listed grades are screening candidates, not interchangeable products or a claim that every grade has a published SITI TDS. Confirm current documentation and the complete formulation.
| Binder / substrate | Handbook-listed grades | Selection consideration |
|---|---|---|
| 2K acrylic / NCO cure | ADDSiL-4051, 4052, 4007 | Amino functionality; verify cure route and surface preparation. |
| Epoxy / glass or silicate | ADDSiL-4040 | Epoxy-functional silane candidate; test hydrolysis and binder compatibility. |
| Epoxy / metal | KOBOND-4017, 4023, 4221 | Metal-affinic candidates; compare adhesion after conditioning. |
| UV / polyolefin primer | KOBOND-4019 | The handbook lists this as a primer; actual PP/PE/TPO pretreatment and adhesion must be validated. |
Handbook slides 92, 94, 98
Start with the actual interface
Adhesion depends on binder chemistry, substrate surface, wetting, surface preparation and cure. An adhesion promoter may be blended into a coating or applied as a separate interfacial treatment. It may react with the binder, interact with an inorganic surface, improve interfacial contact, or support polymer compatibility and entanglement. The mechanism depends on the chemistry and should not be assumed from a product-family name alone. Cleaning, degreasing and appropriate surface treatment remain essential where the substrate requires them.
Match chemistry to the substrate
Functional silanes combine an organic group that interacts with the binder and hydrolysable groups that can form silanols and interact with hydroxylated glass, metal oxides or minerals. Amino, epoxy and methacryloxy functionalities fit different cure routes. Metal-affinic polymeric additives may use acid or phosphate groups, while low-energy PP, PE and TPO can require corona, flame or plasma treatment, or a suitable modified-polyolefin primer. Engineering plastics and metal surfaces should be evaluated individually rather than treated as interchangeable substrates.
Verify durability, not just an initial pass
Compare the intended substrate in its actual condition, including pretreatment, coating thickness and cure. Cross-hatch or peel measurements should be interpreted with failure mode and conditioning history, not only a single number. Where relevant, check wet adhesion, aging and intercoat adhesion. The handbook's product matrices are starting points for laboratory screening; the currently published TDS of a selected grade governs its use.
Formulation guidance
- Identify the failing interface and record substrate preparation.
- Select candidate functionality for both binder and substrate.
- Retest after realistic cure and conditioning; record adhesive versus cohesive failure.
Troubleshooting
- Initial adhesion passes but wet adhesion fails
- Record failure location and conditioning; compare pretreatment, cure and functional-group match.
- Poor adhesion on PP or TPO
- Evaluate surface treatment or a compatible polyolefin primer before extrapolating from metal or glass results.