ProHere®

Superior Binding & Adhesion For Metal Topcoats

Joining metal components for extended use under demanding conditions requires durable and reliable metal fasteners. Electroplating—the process of coating a metal with a thin layer of another metal via electrolysis—is frequently used to improve the corrosion resistance of metal fasteners. Electroplating also improves the tensile strength and hardiness of the metal substrate.

Electroplating is typically a two-step process which includes galvanizing the substrate with a layer of zinc and adding a trivalent chromate layer during passivation. After the substrate is plated, a topcoat is applied to provide additional protection.

Michelman’s ProHere® E water-based dispersions improve the binding properties of the topcoat formulation and promote adhesion of the topcoat to the metal substrate.

ProHere® E enhances binding & adhesion in the topcoat. Topcoat or sealant layer (0.5-4µm thick) Trivalent chromate passivate layer (0.06-0.1µm thick) Zinc alloy layer (8-14µm thick) Substrate Anatomy of a Zinc Alloy Coating

Consistent Performance for Automotive OEMs

Automotive OEMs rely on their supply chain to consistently deliver parts that meet their specifications. Metal fastener suppliers and plating companies typically electroplate small metal parts such as threaded fasteners (like steel bolts and screws) and window fittings (usually made of aluminum or carbon steel) to ensure they can deliver the required performance.

ProHere® E enhances the binding properties of coatings used in electroplating, thereby supporting the key benefits electroplating offers in improving the durability of metal parts in the automotive industry, including:

Corrosion Protection

Effective corrosion protection for small metal parts in automobiles can help reduce repair and maintenance costs, prevent potential operational malfunctions, and improve vehicle performance and longevity. For operators handling these parts, a uniform appearance can provide reassurance of the quality and consistency of the manufacturing process.

Coefficient of Friction (COF) Maintained to Tight Specifications

Whether a vehicle is assembled using automated robots or by employees on the manufacturing floor, maintaining a consistent COF for each metal part helps ensure efficient assembly by meeting industry standards and OEM torque specifications. Following these torque guidelines allows OEMs to enhance quality control, supporting precise, repeatable, and reliable vehicle assembly.

Without proper torque control, loose fasteners can lead to over-stressed parts, potentially causing accidents or equipment failure. By ensuring secure fasteners during assembly, manufacturing personnel can prevent safety hazards, such as fasteners breaking or falling to the floor during production. Well-secured parts help maintain a vehicle's performance in challenging environments and reduce the likelihood of repairs due to loose components.

Adhesion Across Multiple Substrates

ProHere® E enhances the versatility of topcoats by promoting adhesion across multiple substrates. After the electroplating process is complete, topcoats that incorporate ProHere® E exhibit improved adhesion on zinc alloy plated steel, cold rolled steel, and aluminum.

Low Dry Film Thickness and Uniform Application

The use of ProHere® E in coating formulations allows a thinner and more uniform layer of film to be applied to metal substrates. This allows for more complete coverage and a more consistent appearance. A thinner layer also reduces drying time, which helps minimize processing costs.

Consistent Gloss and Transparency With Reduced Iridescence

When formulations incorporating ProHere® E are applied as topcoats, the metal substrate is more uniform in appearance and iridescence is reduced. Gloss level and transparency are appropriate to commercial applications. If appearance matters to your customers, they will appreciate working with products that have a consistent look.

Enhanced Strippability

Residue from coatings formulated with ProHere® E is typically easy to remove, allowing for efficient rack and basket cleaning after coating.

Sustainable and Efficient

ProHere® E’s water-based composition provides formulators with a more environmentally friendly alternative compared to solvent- or powder-based materials. ProHere® additives are PFAS-free, emit fewer VOCs, clean up more easily, and do not require additional, elevated personal protective equipment (PPE) or special handling procedures.

 

Performance That Meets Rigorous Standards

Salt Spray (Fog) Testing

Metal fasteners play a crucial role in automotive manufacturing, securing components in critical areas such as under the hood, within the engine bay, on fenders, and throughout the vehicle. However, these metal parts are constantly exposed to a range of environmental and chemical factors that can compromise their performance. Key contributors include:

ASTM B117, established by ASTM International, is a key standard used by automotive OEMs to test the corrosion resistance of nonferrous metals in a controlled salt spray environment. To evaluate performance, Michelman worked with a third-party laboratory to test metal fasteners treated with a topcoat containing ProHere® E. After 2,000 hours of simulated exposure, the fasteners met the corrosion resistance requirements outlined in the standard.

 

Coefficient of Friction (COF) Testing

ISO 16047:2005 specifies methods for testing the torque-tension relationship of threaded fasteners. The standard helps ensure the reliability and consistency of fasteners in automotive applications where precise tension is critical, including automated manufacturing processes, by evaluating friction, coatings, and lubricants to optimize performance.

Independent third-party testing per ISO 16047:2005 has demonstrated that topcoats including ProHere® E improve the COF consistency of electroplated metal substrates. A summary of the test results can be found in the chart below:

 
No Top coat (Negative Control) 0.16 66.56 5.65 0.11 7.7-9.0 1,000-3,000 34.0-36.0 44.38 0.11 ProHere ® E 00007 0.10 8.5-9.5 <100 20.0-22.0 0.94 44.01 ProHere ® E 00017 0.11 9.0-11.0 100-500 19.5-20.5 1.36 43.30 ProHere ® E 00019 0.10 9.0-11.0 20-250 19.0-21.0 1.55 43.59 ProHere ® E 00102 0 20 40 60 80 Average Torque (N·m) COF pH Viscosity (cps) Solids (%) Target Range 48±8 N·m
66.56 5.65 44.38 0.11 0.94 44.01 1.36 43.30 1.55 43.59 0 20 40 60 80 Target Range 48±8 N·m No Topcoat (Negative Control) ProHere ® E00007 ProHere ® E00017 ProHere ® E00019 ProHere ® E00102 Average Torque (N·m) COF 0.11 COF 0.16 COF 0.10 COF 0.10 COF 0.10
 

Backed by Global Expertise & Security of Supply

Michelman is a significant supplier to the metal coating additives market globally. With R&D and production facilities located in the US, EMEA, and Asia, our team of seasoned technical experts has gained a deep understanding of metal adhesion. Whether you need help in identifying the best solution for your needs, or need guidance regarding the best application methods to use, we can help you determine the most effective way to improve your topcoats.

Michelman’s global supply model enables us to meet ongoing orders for our formulator customers. Our quality control ensures you receive in-spec product on all orders, and we can scale to meet your needs in required timeframes.

 

The ProHere® Family

ProHere® waterborne polymer dispersions and emulsions are specifically designed for use in metal coatings, including ProHere® E polymer resins that can serve as organic binders in a coating formulation, plus ProHere® L lubricants and anti-scratch additives for metal processing and in-use lubricants. The coefficient of friction of industrial metal coatings like those using ProHere® E can be modified by the addition of a small amount of ProHere® L or other Michelman emulsions.

Product Name
Form Type
Product Solids Type
corrosion resistance
chemical resistance
primers
metal adhesion
abrasion resistance
flexibility
enhanced lubricity
clarity
ProHere® E 00001Specialty DispersionPolyolefin Acrylic hybrid
ProHere® E 00002Specialty DispersionPolyolefin Acrylic hybrid
ProHere® E 00007Specialty DispersionPolyolefin Acrylic hybrid
ProHere® E 00017Specialty DispersionPolyolefin Acrylic hybrid
ProHere® E 00019Specialty DispersionPolyolefin Acrylic hybrid
ProHere® E 00101Specialty DispersionPolyolefin Acrylic hybrid
ProHere® E 00102Specialty DispersionPolyolefin Acrylic hybrid
ProHere® L 90012EmulsionHigh Density Polyethylene
ProHere® L 90900EmulsionCarnauba
ProHere® L 90901EmulsionCarnauba