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Home / News / Industry News / Insufficient Film Adhesion? DH-7326N Improves Substrate and Interlayer Bonding
Industry News
2K PU · Amino Baking Coatings · Industrial Coatings · DH-7326N
In two-component polyurethane and amino baking industrial coating systems, the film not only needs good adhesion but must also combine water resistance, salt spray resistance, and mechanical performance. If the film does not bond firmly to the substrate or between layers, peeling, durability decline, and other problems can easily occur during long-term use, affecting product quality and service life.
Insufficient Substrate Adhesion
Coating does not bond firmly to substrate — cross-cut test shows paint loss; peeling more likely after long-term use.
Poor Interlayer Adhesion
Insufficient bonding between layers in multi-coat spray processes, affecting overall film stability.
Water and Salt Spray Resistance Below Standard
Film degrades in humid or salt spray environments, reducing protective performance.
Insufficient Mechanical Performance
Flexibility, tensile strength, and wipe resistance insufficient — affects product durability.
DH-7326N: Polyether-Modified Siloxane Copolymer Adhesion Promoter
DH-7326N is a polyether-modified siloxane copolymer adhesion promoter with good chemical stability and resistance to hydrolysis. It can further enhance bonding capability between film and substrate and between layers, and improve system crosslink density.
The product improves substrate adhesion, interlayer adhesion, and film tensile strength and elasticity, while enhancing resistance to ambient-temperature water immersion, salt spray, water boiling, and wipe testing. It can also extend the working pot life of two-component systems, and is suitable for amino baking coatings and 2K PU industrial coating systems.
| Substrate Adhesion | Improves film bonding to substrate — reduces peeling and paint loss in service |
| Interlayer Adhesion | Strengthens bonding between coating layers in multi-coat systems |
| Water & Salt Spray Resistance | Improved resistance to ambient-temperature immersion, water boiling, and salt spray testing |
| Mechanical Performance | Improves tensile strength and elasticity — coating is more stable under external force |
| Pot Life Extension | Can extend the working pot life of two-component systems, improving application window |
| System Compatibility | Suitable for amino baking coatings and 2K PU industrial coating systems |
For two-component polyurethane and amino baking industrial coatings, adhesion directly relates to coating durability and comprehensive performance. Adding DH-7326N adhesion promoter appropriately can simultaneously improve substrate bonding, interlayer bonding, and water, salt spray, and mechanical performance — providing a more reliable solution for industrial coating.
Frequently Asked Questions
Why is resistance to hydrolysis important for a siloxane-based adhesion promoter?
Siloxane chemistry relies on Si–O bonding at the coating-substrate interface for its adhesion promotion mechanism. If the siloxane groups hydrolyse prematurely — in the wet coating before cure, or in the cured film during water or humidity exposure — the interfacial bond is broken and adhesion performance is lost. DH-7326N's polyether modification and chemical structure are designed to resist hydrolysis, maintaining interfacial bond integrity under the wet conditions that the coating encounters in service.
Can DH-7326N be used to improve adhesion in systems other than 2K PU and amino baking?
It is characterised and recommended for amino baking and 2K PU industrial coating systems where the chemistry is well-matched. For other coating systems — single-component, radiation-cured, or waterborne — compatibility and performance should be evaluated by a trial rather than assuming equivalent performance, as the interaction between the adhesion promoter chemistry and the coating binder affects the outcome.
