Industrial coatings must withstand harsh conditions, including frequent chemical exposure, moisture, temperature swings, abrasion and heavy use. When you think of infrastructure like bridges and highways, farm equipment, or slip-resistant floors in food processing plants, you can appreciate how much wear and tear occurs at these surfaces. The ability of industrial coatings to maintain performance and appearance for an extended time is essential to worker and public safety.
Formulators face the additional challenge of meeting environmental regulations and safety standards while keeping costs under control. Our MINEX® ST filler, a surface-treated naturally occurring nepheline syenite mineral, helps address all three priorities: performance, safety and efficiency. This blog will examine how MINEX ST fillers deliver measurable improvements in coating durability and workability without the risks associated with crystalline silica.
What Sets MINEX® ST Fillers Apart?
MINEX ST fillers build on Covia’s well-known MINEX product line, offering the same high-purity nepheline syenite with an added surface treatment to enhance performance in advanced coating systems. This proprietary surface treatment provides:
- Stronger bonding within the resin matrix.
- Better chemical and water resistance — ideal for polyurea, polyurethane and epoxy systems.
- Enhanced gloss and clarity at higher loadings — perfect for high-gloss coatings and fast-drying systems.
- Faster dispersion and more uniform distribution, reducing the need for additives and speeding up production.
These improvements make it easier to reach high-performance targets, even at higher filler loadings or in moisture-sensitive systems.
As Covia Sr. Applications & Technology Manager for Coatings & Polymers Scott Van Remortel put it, “Nepheline works really well. It’s a very versatile filler. It has no weaknesses—but if we could improve one thing, it would be the chemical and water resistance.” With its proprietary surface treatment, the MINEX ST filler fulfills this promise. It is available in three particle sizes (4, 7 and 10), and it comes in two specialized treatments: A100, which is compatible with water- and solvent-based epoxies, as well as 1K and 2K waterborne polyurethane systems, and OV100, a hydrophobic treatment for solvent-borne polyurethane, polyaspartic, polyurea and epoxy systems, where moisture sensitivity can lead to film defects.
MINEX ST fillers are well-suited for solvent and water-based adhesives, including polysulfide and urethane formulations.
A Safer Approach to Compliance and Performance
Respirable crystalline silica (RCS) is a health and safety concern in industrial settings. This fine dust can lead to serious respiratory issues and has been identified as a workplace hazard by the Occupational Safety and Health Administration (OSHA). Many fillers commonly used in coatings, including quartz-based products, can contribute to RCS exposure during production, application or sanding. That’s where MINEX ST fillers make a difference. Nepheline syenite is naturally deficient in crystalline silica, eliminating RCS exposure risks entirely.
Switching to a filler low in crystalline silica can help companies meet regulatory standards, reduce liability and create a safer work environment. With no crystalline silica, MINEX ST fillers also simplify the path to meeting low-VOC targets in regulated markets, thanks to their high compatibility with resins and efficient dispersion. That means fewer additives, lower emissions and a more efficient formulation process overall.
Applications Where MINEX ST Fillers Shine
MINEX ST fillers have been successfully tested in several industrial and specialty applications, including:
- General Industrial Coatings: Enhance gloss and color retention and chemical and water resistance on trailers, heavy equipment and buses.
- Industrial Floor Coatings: MINEX ST mineral fillers perform exceptionally well in polyaspartic, epoxy and polyurethane systems, with three particle size options for gloss, intermediate and low sheen, where durability is essential.
- Adhesives: Supports strength and stability in urethane and polysulfide adhesives.
- Industrial Wood Coatings: Improves gloss control, dispersion and burnish resistance in pigmented systems for furniture, cabinetry and millwork.
- Protective Coatings: Adds extra strength and durability to structural steel used in bridges and stadiums, as well as infrastructure found in heavy industry, including mining, oil and gas; chemical processing; water storage and transmission; wastewater treatment; and power generation and transmission. Imparts protective qualities to storage tank linings used in rail tank cars, food and beverage production facilities, pharmaceutical manufacturing, amusement parks and recreational facilities.
If you’re formulating for more basic systems like alkyds or standard acrylics, stick with the original MINEX grades, which work well with these chemistries.
Efficiency Gains That Add Up
In addition to boosting performance and safety, MINEX ST fillers also improve efficiency. Enabling higher loadings and faster dispersion can reduce the overall amount of resin needed, which means cost savings and lower VOCs.
These operational advantages complement the product’s performance and safety benefits and help streamline production. “This is an exceptional product, highly versatile with significant economic benefits,” said Van Remortel.
Testing and Production Support You Can Count On
MINEX ST mineral fillers are manufactured in Utica, Illinois, under strict quality control. Covia’s unparalleled technical and customer service teams support customers. Distributors and formulators have access to samples, technical data and expert assistance with product evaluation and implementation.
Application testing is underway, noted Van Remortel, and customers are satisfied with the results. “Customers have already trialed it and purchased material for production runs and field trials. We’re excited to see the positive impact this product will have.”
Ready to Evaluate MINEX ST Fillers?
Learn more, request a sample, explore our application resources or talk with a Covia expert about how MINEX ST mineral fillers can help you meet your formulation goals.
