Search

The first thermal paper technology was developed in the 1930s. Since then, thermal recording systems have branched into two main groups, two-component systems and heat-transfer systems. In the 1960s, the leuco dye system was developed by NCR. This type of system has been used mainly in thermal recording systems. The leuco dye system however has some drawbacks such as poor image stability and an artificial texture. In a recent development, a compound with an epoxy functional group was added to the thermal sensitive layer of a leuco dye thermal paper to obtain good stability. A special overcoat layer gives the product the texture of plain paper. In addition to this product, other special thermal papers have been developed, such as two-color thermal paper, IR readable thermal paper, high resolution thermal paper, and translucent thermal paper.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The coating color for the direct thermal paper basically consists of the leuco dye, the cobr developer and the sensitizer. Blacking dyes to be used for thermal papers call for other practicable properties than the tone, such as storage stability, thermal sensitivity and white background. Since no universally accepted theory in choosing proper developer and sensitizer is available, however, selection will have to be conducted on the designer's experience. Such practical considerations as the stability of the recorded image and matching with the particular machine to be used for are important beside the chemical considerations.