HX AP-13 Orthophosphate
Anti-rust pigment
Technical Information
What Is HX AP-13 Orthophosphate
HX AP-13 is a high-performance, white anti-corrosion pigment based on orthophosphate chemistry. Engineered with narrow particle distribution, low oil absorption, and uniform particle morphology, it delivers superior dispersion characteristics and consistent film quality across a wide range of coating systems. The orthophosphate structure provides rapid substrate passivation, making AP-13 the most versatile pigment in the HX anti-rust series — suitable for everything from decorative emulsions to automotive coatings. Its balanced oil absorption (18-33 g/100g) and neutral pH (6.0-9.0) ensure broad compatibility with solvent-based, waterborne, and powder coating formulations.
Key Features
- Narrow Particle Distribution — Uniform particle size (D50: 2.0-6.0 μm) with controlled morphology ensures consistent dispersion batch-to-batch
- Low Oil Absorption (18-33 g/100g) — Allows high pigment loading while maintaining flow and leveling properties
- Rapid Passivation — Orthophosphate chemistry provides fast-acting corrosion inhibition on ferrous substrates
- Universal Compatibility — Neutral pH (6.0-9.0) works across solvent-based, waterborne, and powder systems without binder interaction
- Smooth Film Finish — Sieve residue <1.0% at 45 μm ensures no surface defects in thin-film applications
- Automotive-Grade Performance — Validated for OEM and refinish applications requiring stringent corrosion and appearance standards
Recommended Applications
| Application | Suitability |
|---|---|
| Automotive OEM | ✅ Recommended |
| Automotive Refinish | ✅ Recommended |
| Industrial Paints | ✅ Recommended |
| Powder Coatings | ✅ Recommended |
| Decorative Water Base Paints | ✅ Recommended |
| Decorative Solvent Base Paints | ✅ Recommended |
| Decorative Universal Stainers | ✅ Recommended |
✅ Recommended | ⚪ Suitable | ❌ Not Recommended
Technical Data
| Physical Form | White powder |
| Oil Absorption | 18-33 g/100g |
| Water Soluble Matter | < 1.5% |
| pH Value | 6.0-9.0 |
| 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
What makes orthophosphate different from other anti-corrosion pigments?
Orthophosphates like AP-13 provide faster initial passivation compared to polyphosphates (AP-10) or silicates (AP-12). The simpler molecular structure means phosphate ions are released more readily at the metal-coating interface, forming a protective layer within hours rather than days. This makes AP-13 particularly valuable in applications requiring rapid corrosion protection — such as automotive coatings where parts may be handled or exposed shortly after painting.
Why is HX AP-13 the only grade in the series recommended for automotive OEM?
Automotive OEM coatings demand three things simultaneously: excellent corrosion resistance, flawless surface appearance, and consistent batch-to-batch performance. AP-13’s narrow particle distribution and uniform particle shape deliver the surface smoothness required for Class A finishes, while its rapid passivation kinetics meet the corrosion performance specs (typically 500+ hours ASTM B117). The controlled manufacturing process ensures the consistency that automotive QA systems require.
Can HX AP-13 be used as a universal anti-corrosion pigment across all product lines?
AP-13 is the most versatile grade in the HX series and can serve as a single anti-corrosion pigment across most coating lines. However, for cost-optimized formulations where premium automotive performance is not required, AP-11 provides excellent corrosion protection at a lower cost point. For highly alkaline systems (pH >9), AP-12’s silicate chemistry may offer better long-term stability. Consider your most demanding application when selecting the right grade.
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.