TEGO® Dispers 780 W for high-quality waterborne pigment concentrates
Benefits at a Glance
- Provide best stabilization of pigments and fillers in aqueous dispersions
- Suitable for binder-containing and binder-free colorants with all pigment types
- Good viscosity reduction
- Outstanding color strength development
- Especially efficient against binder shock of binder-free colorants
Evonik has a long-standing history as a supplier of wetting and dispersing additives combined with a good understanding of the general structure-property relationships that drive the performance attributes of polymeric structures. Through comparison with commercial benchmark additives and formulation design, Evonik has developed a new wetting and dispersing additive to overcome the challenges encountered when formulating waterborne pigment concentrates. This new dispersant is TEGO® Dispers 780 W, that provides excellent pigment stabilization for organic and inorganic pigments in binder containing as well as binder-free colorants. TEGO® Dispers 780 W is a polymeric, slightly anionic wetting and dispersing additive. It is an excellent choice in colorants for tinting industrial coatings and façade paints.
Favorable environmental and safety profile:
Ensuring the safety of the user and of the environment is a key priority for chemicals suppliers. To fulfill the increasing stringent regulatory requirements, Evonik has developed a product that is safe to use and respectful of the environment. TEGO® Dispers 780 W is a non-hazardous solvent-free liquid that is easy to handle. In addition, it is also compliant with numerous food contact regulations, making it an ideal candidate for formulations coatings that use for food applications.
Outstanding benefits in pigment concentrates:
Its benefits in pigment concentrates are outlined in this article through comparisons of existing technology with this newly designed pigment dispersing additive. This novel technology is shown to offer significant performance improvements in viscosity profile, color strength, stability combined with increasing efficiency and compatibility for both organic and inorganic pigment types in waterborne systems.
Viscosity reduction and color strength are the most critical key performances when evaluating pigment dispersions. To determine the advantages of TEGO® Dispers 780 W for pigment concentrates, pigment preparations based on phthalocyanine blue with color index PB15:3 and iron oxide red PR101 were tested with the rheometer. This test was repeated on aged samples to determine the storage stability of the pastes after two weeks at 50° C.
In parallel, a white coating containing a polyurethane-acrylic binder was tinted with both pigment concentrates. The tinted coating samples were applied on Leneta card with a wire bar. A rub-out test was performed, and color strength was evaluated with a colorimeter.
The graphics below show that for both pigment types, TEGO® Dispers 780 W provides very low viscosity value combined with a good stability over time, similar to an industry standard dispersant based on a high polymeric structure.
In addition, the results on color properties obtained on the samples containing TEGO® Dispers 780 W are clearly outstanding. Not only the color strength is significantly increased, especially in the case of the phthalocyanine blue pigment dispersion, but also the compatibility is maintained to a very good level with a delta E value below one. When looking at the results obtained with the iron oxide base coating samples, we observed a significant reduction of the delta E values as well, indicating an improved color acceptance.
These tests were extended to a larger range of pigments and showed the great efficiency of TEGO® Dispers 780 W for the following pigments: quinacridone pigment (C.I. PR 122), beta phthalocyanine blue pigment (C.I. PB 15:3), Hostaperm® Violet RL special (C.I. PV 23) , BAYFERROX® 130 M (C.I. PR 101) or BAYFERROX® 3920 (C.I. PY 42).
TEGO® Dispers 780 W also provides very good corrosion resistance properties as can be seen on the pictures below taken after salt spray test (ASTM after 1200 h) on phosphated steel compared to an industry standard. The formulation used for the test is a waterborne industrial coating based on a two-component polyurethane-acrylate binder with two different pigment dispersions (PB15:4 on the left and PR101 on the right).
Summary
TEGO® Dispers 780 W is a new addition to the wetting and dispersing additive portfolio of Evonik. It is designed for waterborne binder and binder-free pigment concentrates based on organic as well inorganic pigments. TEGO® Dispers 780 W offers great performance benefits for viscosity reduction and stability and color development combined with an outstanding environmental and safety profile.
