Printing inks: “We are working on PTFE-free wax additives”
Why are you looking for alternatives to PTFE in inks? What are the regulatory requirements? Dr Gehan Eltanany: Regulatory measures targeting specific types of per- and polyfluoroalkyl substances (PFAS) have been in place for years, with some measures restricting certain PFAS down to parts per billion (ppb) levels. One example that impacts PTFE is the recent REACH Regulation (EC) No. 1907/2006, on Per-Fluoro-Octanoic-Acid (PFOA) and its salts as persistent organic pollutants (POPs). The restriction on PFOA has impacted the use of certain types of PTFE due to common production processes that utilise irradiation. The irradiation process that is used to create low molecular weight PTFE, often required for the inks industry, is known to generate PFOA as a byproduct. Traditional processes are known to generate PFOA in the range of parts per million.
Within this new regulatory environment, ink formulators and manufacturers need to be prepared to adapt their ink technologies to be compliant. Specifically, the need for PFOA compliance (i.e., levels below limits specified in the EU regulation), PTFE or PTFE-free alternatives have been greatly expedited. Therefore, traditional PTFE will need to be replaced with low-PFOA containing PTFE or PTFE-free alternatives using new low-PFOA PVDF or PVDF-free resins.
What alternatives to PTFE are you working on, and what are their benefits and challenges?
Eltanany: PTFE-based wax additives are common fluoropolymers used in a wide range of industries for their many desirable properties, including exceptional chemical resistance, low coefficient of friction, and enhanced surface durability. These properties make them especially useful in printing inks. We are working on PTFE-free wax additives. PTFE-free wax additives have been developed using new and alternative raw materials that exhibit similar functional performance as PTFE-based options.
For example, PTFE-free wax additives offer number of benefits, such as rub resistance and slip, when used as a replacement for waxes containing PTFE. Additionally, these additives are suitable for aqueous, solvent-based and 100 % UV ink systems. When these waxes are incorporated into an ink formulation, it not only improves gloss retention, but also reduces coefficient of friction and increases the rub resistance. The New Lubrizol technology serves as a viable alternative to PTFE. These PTFE-free formulations deliver similar properties to PTFE-containing.
In addition to identifying replacements for PTFE, our approach to solving the PTFE replacement challenge is to work closely with customers to identify specific performance requirements and creating products that have these specific characteristics.
Do you expect further regulatory restrictions regarding printing inks in the near future?
Eltanany: The chemical regulatory environment is constantly evolving (e.g., emerging chemical control laws, restrictions on use, classification and labelling). One activity that is expected to increase in the near future is restricting groups of chemistry at once. Per- and polyfluoroalkyl substances (PFAS) are a good example. As discussed above, regulatory measures are already in place for specific PFAS that exhibit persistence in the environment and human body and other health hazards.
Regulators/NGOs/Companies across the globe have since shifted their focus to the broader chemical class. The definition of PFAS in scope of recent, and near term, regulatory action can be different depending on the region, however, most proposals aim to encompass all chemistry with a fully fluorinated carbon atom. Most pressing is the European proposal recently submitted to ECHA that seeks to restrict PFAS under EU REACH Annex XVII. ECHA has published the detailed proposal on 7 February 2023.