Reducing Costs in Water-Based Paints with Portafill H10 Natural TiO2 Extender

 

Introduction:

In today's society, the use of paints for the aesthetics and durability of structures is increasing day by day. On the other hand, rising raw material prices and cost pressures remain another important factor. More efficient use of TiO2, which is the most important filler input and cost item in paints, is gaining parallel importance. Sibelco recommends its use together with Portafill H10 material to reduce TiO2 consumption. Portafill H10, a type of huntite material, is produced in Sibelco's own mine located in Thessaloniki, Greece. Huntite, whose main mineral content is magnesium calcium carbonate, has a platy-lamellar structure and bright appearance. During production, careful attention is paid to the raw material source and chemical content, meticulous work is carried out to ensure particle distribution is uniform and within a narrow range, and continuous strict quality control operations are performed on the final product to consistently deliver high-quality material.

Figure 1: Portafill H mine and production facility

Portafill H10:

Portafill H10 is characterized by the following parameters: • Particle size and distribution, • Mineral shape, • Brightness. With its very fine particle structure of approximately 1 μm, Portafill H10 mixes well with similarly fine TiO2 particles. The lamellar-platy structure of Portafill opens agglomerated titanium particles and ensures their excellent dispersion in the paint. Thus, high opacity values in decorative paints are achieved with less TiO2 usage. The high brightness value of Portafill ensures that adverse effects that could result from using less titanium are minimal or remain limited depending on its use in the formulation.

How Does Portafill H10 Work?

Portafill H10 is more suitable for use in water-based paints above the critical PVC value stated as CPVC, but can also be used in formulations below the critical PVC value and performs the same function. Specifically: Paints Above Critical PVC Value: Due to low binder ratio, TiO2 particles are more prone to agglomeration, and Portafill H10 breaks them up. Paints Below Critical PVC Value: It prevents agglomeration of TiO2 particles following water evaporation and film formation. Since better utilization of existing TiO2 is achieved, it allows either obtaining paint with better properties (for example, hiding power) or using less titanium.

Portafill H10 is added to the paint mixture like other fillers, preferably after TiO2. Following mixing, during the dispersion phase, it breaks up agglomerates as shown in Figure 2.

Figure 2: TiO2 particles mixed with Portafill H

To ensure stability, Sibelco recommends the use of ammonium polyacrylate-based dispersant at a ratio of 0.5-1.0% of the total formulation weight. This ensures that the paint's rheological properties remain stable during storage and shelf life without adversely affecting other properties. Example 1: Portafill H10 vs PCC Comparison Table 1: Wall Paint Formulation (70% PVC)

Evaluation has been conducted on the following points according to these formulations:

• Viscosity profile, • Color, • Wet scrub resistance, • Hiding power, • Brightness.

Color

Table 2: Whiteness Test Results

When Portafill H10 is used in a 1:1 ratio instead of PCC, the whiteness value is approximately the same. When the PCC amount is doubled, the whiteness value increases further; the main reason for this is that PCC, being a synthetic mineral, has a higher whiteness value than Portafill H10, which is a natural mineral.

Wet Scrub Resistance

Table 3: Wet Scrub Resistance Results Scrub resistances are very similar, therefore Portafill H10 has no negative effect on scrub resistance.

Brightness / Gloss

Table 4: Brightness Test Results

When Portafill H10 is used, mattness increases slightly.

Hiding Power

Figure 5: Hiding power

  As seen in Graph 5, Portafill H10 shows clear superiority over PCC in hiding power values. Even when the PCC filler is doubled, Portafill H10's hiding power is still better. This demonstrates that Portafill H10 is a better TiO2 extender than PCC.

Summary evaluation of these 3 scenarios using Portafill H10:

• When H10 is used one-to-one instead of PCC: - Better hiding power, - Similar whiteness value, - Better matte effect, - Similar wet scrub resistance, - Slightly higher viscosity at lower shear rates. (This also provides cost advantage by using less rheology agent) • When less H10 is used instead of PCC: - Similar hiding power, - Same whiteness levels, - Similar matte effect, - Similar wet scrub resistance, - Approximately same viscosity at lower shear rates. • When less TiO2 is used: - Similar hiding power, - Same whiteness levels, - Similar matte effect, - Similar wet scrub resistance, - Slightly higher viscosity at lower shear rates. (This also provides cost advantage by using less rheology agent)

Other Comparison Examples

Upon request, comparison examples and test results such as the following can be provided: • Portafill H10 vs Aluminum Silicate, • Portafill H10 vs Hydrous Kaolin, • Portafill H10 vs Calcined Kaolin.

Conclusion and Evaluation

This study demonstrates that Portafill H10 is a successful TiO2 extender. Main advantages: • Being a natural and economical product, • High whiteness value, • With its lamellar-platy structure, it is highly suitable for breaking up titanium agglomerations and prevents re-agglomeration after drying. • While reducing titanium and thickener usage, the following basic properties are preserved: - Viscosity, - Color, - Wet Scrub Resistance, - Hiding Power, - Brightness, • And it is more economical compared to other TiO2 reduction products. Author: William Mertens Paint Technical Sales Director Sibelco Translator: İlyas Küreli Sales Manager CHS Industrial Products