| abstract |
The present invention provides a transparent or colorless coating comprising a heat responsive material that increases in opacity when exposed to heat. An example of a heat responsive material is an inorganic compound or an organic resin. The present invention further provides a coating composition comprising a carrier and a heat responsive material. The coating can further include additives such as an adhesion promoter, a defoamer, a crosslinking agent, a plasticizer, a humectant, a pH adjuster, a biocide, a co-solvent, a surface tension modifier, and/or a combination thereof. The present invention further provides a method for creating a mark on a substrate comprising providing to the substrate the transparent coating to obtain a coated substrate and exposing a selected area of the coated substrate to heat, e.g., a laser, to create the mark. The present invention further provides substrates suitable for laser marking. |