Polytetrafluoroethylene (PTFE) is a synthetic polymer consisting of two simple elements—carbon and fluorine—that is derived from tetrafluoroethylene (TFE). It was discovered by accident in 1938 when a scientist was working with gases related to refrigerants. A frozen, compressed sample of TFE had spontaneously polymerized into a white, waxy solid to form PTFE. While PTFE isn’t a household name, Teflon™ is a brand of PTFE that is widely recognized.
PTFE is inert to virtually all chemicals and considered the most slippery material in existence. In addition to low coefficient of friction, it provides excellent resistance to heat and low temperature and enhanced surface durability with scratch and abrasion resistance. That’s why it has been widely used across a range of industries, including coatings and inks.
Irradiation Creates PFAS
PTFE for inks and coatings requires a low molecular weight, which happens through the irradiation process. That process creates potentially carcinogenic per-and polyfluoroalkyl substances (PFAS) such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA).
Unfortunately, many PFAS are toxic with no proven environmental degradation. Because of their widespread use and their persistence in the environment, many PFAS are found in the blood of people and animals all over the world and are present at low levels in a variety of food products and in the environment. Scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals.
These concerns have not gone unnoticed by government regulators. Regulations from 2019 in the EU restrict the use of raw materials containing >25 ppb PFOA, which impacts the use of PTFE because of common production processes that use irradiation.
Ink formulators and manufacturers are working to adapt by exploring compliant solutions—typically PTFE-free materials—that maintain the same performance properties PTFE offers. PTFE-free materials have been gaining in popularity in packaging inks and are beginning to take hold in the coatings industry.
Wax additives play an important role in replacing traditional PTFE with low-PFOA containing PTFE or PTFE-free alternatives to meet the technical challenges of reducing or removing PFOA from customer products in multiple ways. PTFE-free wax additives use new and alternative raw materials that are functionally similar to PTFE.
Lubrizol’s technical team has focused on the development of PTFE-alternative wax additives to deliver similar properties to PTFE-containing additives. PTFE-alternative technologies are available in micronized and dispersed forms of surface modifying additives under the Lanco™ Surface Modifiers brand. More products are currently under development to meet specific customer needs and to provide additives for a wider range of applications, and existing products can be customized as needed to avoid PTFE.
Put to the Test
PTFE-free waxes were put to the test by adding them to ink formulations. Testing demonstrated that these waxes offer a number of benefits when used as a replacement for waxes containing PTFE. Incorporated into an ink formulation, PTFE-free waxes improved the gloss retention while also reducing the coefficient of friction and rub resistance. The results demonstrated that PTFE-alternative wax additives offer a viable replacement for PTFE-based products.
Contact a Lubrizol expert to learn more about our line of PTFE-alternative wax additives.