Zeolitic rock as a new pigment for ceiling paints.

The performance of a zeolitic rock, mainly clinoptilolitic (heated at 350 °C) is studied as humidity and ammonia adsorber in ceiling paints. The paints were formulated with 39% and 75% of zeolitic rock by volume of the total pigment content and 75% and 85% pigment volume concentration (PVC). A blank, without zeolitic rock, was also formulated. The performance of the paints were assessed by gas (water and ammonia) adsorption and adsorption-desorption cycled tests. The results show that the paints containing zeolitic rock have better performance than the blank. Moreover, paints with 75% PVC behaved better than paints with PVC 85%. This behaviour may be due to the higher pigment content because the paints with PVC 85% retain more water during the curing period diminishing their adsorption capacity.