The shortage of titanium dioxide and the resulting price increase has once again motivated paint chemists to look for alternatives to this key raw material to increase paint hiding power. To this end, Arkema has recently introduced two new technologies -- Celocor TM covering polymer and a new dispersant that can improve the covering efficiency of titanium dioxide. This article describes the performance of these two new technology products, and shows how to effectively use the combination of these two technologies to significantly reduce the amount of titanium dioxide required in paint formulations through their application examples in 4 latex paints.
Dry hiding power is also called contrast ratio. Prepare a uniform coating film white test paint on the Leneta 3B picture . After drying for 24 hours under constant temperature and humidity conditions of 25 °C and 50% relative humidity, use a Colorimeter Measure the Y- reflectance on the white and black parts of the picture. The contrast ratio is the ratio of the Y value of the black part to the white part. The higher the contrast ratio, the stronger the hiding power.
Scrub resistance
Relative scrub resistance was tested using a Garner Linear Scrub and Abraser . The preparation and testing procedures of the coating film samples are as follows: prepare a coating with a wet film thickness of 7 mils on Leneta black plastic drawings, and dry the paint film under constant temperature and humidity conditions of 25 °C and 50% relative humidity for 7 days. The nylon bristle brushes were run back and forth 400 times prior to testing . The test uses a standardized abrasive scrubbing medium (#SC-2 from Leneta Corporation) with 7 mL of scrubbing medium and 5 mL of water added initially and after every 400 cycles.
The test was repeated 3 times for each sample and the number of brush cycles . A scrub resistance control sample was included on each test chart
