HX AP-12Modified Silicate
Anti-rust pigment
Technical Information
What Is HX AP-12 Modified Silicate
HX AP-12 is a white, non-toxic anti-corrosion pigment based on modified silicate chemistry. Unlike phosphate-based inhibitors, the silicate ion-exchange mechanism provides corrosion protection through the formation of a stable, inert barrier layer on metal substrates. With a high pH range (8.5-11.5), HX AP-12 is particularly effective in alkaline coating systems where acidic pigments may cause binder instability. Its balanced oil absorption (19-29 g/100g) and controlled particle size (D50: 2.0-6.0 μm) make it a versatile choice for both waterborne and solvent-based industrial maintenance coatings.
Key Features
- Silicate-Based Chemistry — Forms a durable ion-exchange barrier layer, offering distinct corrosion inhibition compared to phosphate or zinc-based pigments
- High pH Stability (8.5-11.5) — Ideal for alkaline binder systems where acidic anti-corrosion pigments may compromise stability or cause flash rusting
- Environmentally Compliant — Non-toxic, heavy-metal-free formulation meeting global eco-label standards
- Low Sieve Residue (<1.0% at 45 μm) — Ensures smooth film surfaces in thin-coat applications
- Broad Application Range — Effective in waterborne, solvent-based, and powder coating systems
- Cost-Effective — Delivers reliable corrosion protection at competitive economics for general industrial applications
Recommended Applications
| Application | Suitability |
|---|---|
| Industrial Paints | ✅ Recommended |
| Decorative Water Base Paints | ✅ Recommended |
| Decorative Solvent Base Paints | ✅ Recommended |
| Decorative Universal Stainers | ✅ Recommended |
| Powder Coatings | ⚪ Suitable |
| Automotive OEM | ❌ Not Recommended |
| Automotive Refinish | ❌ Not Recommended |
✅ Recommended | ⚪ Suitable | ❌ Not Recommended
Technical Data
| Physical Form | White powder |
| Oil Absorption | 19-29 g/100g |
| Water Soluble Matter | < 1.5% |
| pH Value | 8.5-11.5 |
| Sieve Residue (45 μm) | < 1.0% |
| Primary Particle Size D50 | 2.0-6.0 μm |
Packaging
25 kg/bag. Custom packaging available upon request.
Frequently Asked Questions
How does silicate-based corrosion inhibition differ from phosphate-based?
Phosphate pigments (like AP-10 and AP-11) inhibit corrosion primarily through ion-exchange and substrate passivation — phosphate ions react with the metal surface to form a protective layer. Silicate-based pigments like AP-12 work through a different mechanism: they release silicate ions that form a stable, glass-like barrier film on the substrate. This barrier is particularly durable in alkaline environments, making AP-12 the preferred choice for high-pH coating systems where phosphate passivation may be less effective.
Why is the pH range of HX AP-12 so high (8.5-11.5)?
The alkaline pH is inherent to the silicate chemistry. This makes AP-12 naturally compatible with alkaline binder systems — including many waterborne acrylics, epoxy-amine systems, and silicate-rich formulations. In these systems, AP-12 maintains stability without the pH drift that can occur with acidic anti-corrosion pigments. For acidic or neutral-pH systems, consider AP-10 (pH 5.0-8.0) or AP-11 (pH 6.0-9.0).
Can HX AP-12 be used in combination with phosphate-based pigments?
Yes. Many formulators use a hybrid approach — combining a small amount of phosphate pigment (for rapid early passivation) with silicate pigment (for long-term barrier protection). The synergistic effect can provide better overall corrosion resistance than either pigment alone. However, the pH difference between silicate and phosphate pigments means the binder system must have sufficient buffering capacity. Always run compatibility testing before scaling up a hybrid formulation.
Disclaimer — This Technical Data Sheet reflects our best understanding of typical product properties at the time of publication. Listed values are representative of standard production and are not intended as specifications, contractual parameters, or fitness guarantees. Batch variations within normal manufacturing tolerances may occur; users should verify critical parameters against their own requirements before use. Processing methods, formulations, and end-use environments are beyond the manufacturer’s control. The buyer assumes full responsibility for confirming product suitability through its own testing and quality assurance. No intellectual property license is granted or implied. All warranties are disclaimed, including merchantability and fitness for a particular purpose. The manufacturer is not liable for incidental, consequential, or special damages. All sales are governed by the manufacturer’s standard terms, available upon request. This product may contain particles below 0.1 μm.