|MadSci Network: Chemistry|
Original dry-erase and permanent marker inks all used benzene-containing solvents.By the last decade, Dry-erase ink manufacturers switched their solvents (ink carriers)to ethanol/isopropanol (alcohol-based) to claim less toxicity and "low odor" which were main complaints stemming from these original solvents. Most current dry-erase products that can be purchased today are certified non-toxic (written on package copy). Regarding ingredients, all alcohol-based dry-erase marker inks contain 4 basic ingredients: 1. Carrier (solvent)- as previously stated, either ethanol or isopropanol or a mixture thereof; provides fast-drying, less tendency to smear 2. Colorant- predominantly pigments, most popular of which is carbon black; for opacity and color permanence and vibrancy 3. Release agent- an oily (can be simply a mineral oil) surfactant or co- solvent which will coat the board to provide easy erase barrier (such that the colorant slides off of the board surface and does not penetrate or stain over time) 4. Lastly, the ink contains a small amount of a polymer or resin that helps the ink spread evenly on the board surface (so the ink does not bead up) and helps the ink to be cohesive (as opposed to adhesive)
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