Interview with Kirstin Schulz and Roger Reinartz

In 2000, she joined Evonik Industries in Essen where she was responsible as senior manager for industrial coatings. Since 2015, she has been spearheading marketing for industrial coatings in the EMEA region. Roger Reinartz received degrees in chemistry and chemical engineering from the Technical University of Eindhoven - Netherlands. In 2001, he joined the Specialty Additives business of Air Products Netherlands B.V., where he worked as a lead research chemist and technical manager for over 10 years. Following the 2017 acquisition of Air Products' Specialty Additives business by Evonik, he transferred to the Coating Additives business line in Essen, Germany and became the Group Product Manager for hydrophobing, flow, and glide additives. In 2018, he took the role as Head of Applied Research and Technology for industrial coatings in the EMEA region, specifically focusing on paper, plastic, and leather coatings.

In automotive coatings, industrial coatings, and even printing inks, SURFYNOL® 104 has long been one of the most well-known and successful additives in the global paints and coatings industry. The 2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD) chemistry has proven to improve substrate wetting and defoaming issues for decades with minimal side effects. This makes TMDD unique in waterborne coatings.

Our new next-generation additive is just as effective as its predecessor but with one crucial benefit: It contains virtually no VOCs (depending on regional guidelines and measuring method).

TMDD is a waxy, difficult-to-handle substance that requires a special solution during production. Based on tightening VOC regulations, the solvents in the aforementioned solution are under scrutiny. To combat this challenge, the Coating Additives business line of Evonik has developed a nearly-VOC-free solution (depending on the regional legislation and definition of VOC).

The new SURFYNOL® 104 Z is the next member of the globally successful SURFYNOL® 104 technology. This new additive is a multi-functional, low-VOC, HAPS-free surfactant that boasts more favorable labeling. With this, SURFYNOL® 104 Z supports worker safety and enables future-proof coatings that will have to meet undoubtedly tighter regulations in the future.

Kirstin Schulz: Globally, we noticed that end-customers (and, as a result, the coatings industry) are much more interested in protecting the environment and ensuring worker safety than in the past. When developing the SURFYNOL® 104 successor, we took all of these aspects into consideration. We can finally offer an easy-to-handle, reduced-VOC solution that can be used as drop-in replacement for existing SURFYNOL® 104 solutions wherever end-customers or legal requirements demand improvement of existing formulations and/or new developments.

I. SAFETY

Roger Reinartz: Safety is our top priority, and it was embedded in the development of SURFYNOL® 104 Z. We received constant requests from the market to have a 50%-active liquid version of SURFYNOL® 104 with improved product labeling. Extensive toxicology testing allowed us to remove both the health hazard symbol (list alongside SURFYNOL® 104 E and H) as well as the corrosive symbol that all other SURFYNOL® 104-solvent cuts have. In other words said, the toxicology testing allowed us to drop for the following hazard phrases for SURFYNOL® 104 Z:

1. H317 - May cause allergic skin reaction

2. H318 - Causes serious eye damage

3. H373 - May cause damage to organs through prolonged or repeated exposure

II. VOC

Roger Reinartz: SURFYNOL® 104 is a solid/waxy material at room temperature and needs to be heated to approximately 60°C to completely melt the product. To overcome this and create a pourable liquid additive, it is provided in a wide range of solvents cuts. However, these solvents are all VOC-contributing according to the main European and US directives and guidelines. With SURFYNOL® 104 Z, we have responded to the needs of our customers by developing a multi-functional additive that meets the increasingly stringent environmental VOC demands while maintaining the unique and well-known high level of performance.

Roger Reinartz: The original SURFYNOL® 104 surfactant is the benchmark by which many surfactants are measured. Striking a balance between wetting and foam control is a challenge that plagues many formulating chemists. Traditional wetting agents are usually very foamy, and effective defoamers can interfere with wetting. As a result, minimizing foam while enhancing wetting becomes a constant balancing act. With this new SURFYNOL® 104 Z Gemini-surfactant, however, the balance is built-in.

Surface-tension reduction is an important property of any surfactant because it promotes the wetting of substrates with surface energy less than the surface tension of water. While steady state reduction in surface tension can give the formulator a quick gauge of a surfactant’s effectiveness, many industrial applications never reach equilibrium. Therefore, in processes where surfaces are generated at a rapid rate (such as printing, spray, roll coatings, curtain coatings, etc.), it is important that the surfactant migrates rapidly to the interface to prevent film retraction and other surface defects.

SURFYNOL® 104 Z lowers surface tension under conditions of rapid surface formation (see Graph 1). This is due to its unique ability to migrate quickly to newly formed interfaces. As a result, SURFYNOL® 104 Z performance under dynamic conditions significantly surpasses that of conventional surfactants.

SURFYNOL® 104 Z belongs to the class of molecular defoamers that provide the multi-functional performance associated with foam control and dynamic wetting. Its name is built on the fact that the defoamer is based on a unique molecule. Molecular defoamers are surface-active agents, which break foam at a molecular level, rather than through incompatibility as seen with conventional defoamers (see Graph 2). At the foam interface, molecular defoamers reduce the film elasticity of bubbles to prevent stabilization. They also reduce surface viscosity of the foam lamella and increase the liquid drainage rate by interrupting the packing of the foam-stabilizing components. These combined effects enhance their defoaming efficacy. Furthermore, molecular defoamers are easily incorporated into aqueous systems, thus eliminating the need for high shear forces which can entrap air during the incorporation process.

It is because of this multi-functional nature that SURFYNOL® 104 has been widely used in the coatings and inks industries as a multi-functional problem solver for decades.

SURFYNOL® 104 Z is a multi-functional Gemini surfactant. Besides the lower VOC content and improved product labeling, SURFYNOL® 104 Z still offers the benefits that its parent SURFYNOL® 104 is known for. It defoams, it wets, and it improves leveling. And above all, it has no negative impact on the formulation. As required, the product can be used at any stage of the formulation process: in the mill base, the let-down, in production or during subsequent quality control.

It contains 50% active substance and as with the previous generation, the new additive is also suitable for applications requiring food contact compliance; it meets FDA and Swiss A requirements. The new additive is HAPs-free, has no Prop-65 declaration and helps formulators to transition more easily from solventborne to waterborne systems.