thermal paper
thermal paper is placed in an environment above 70 ℃, the thermal coating begins to change color. The reason for its discoloration should also be talked about from its composition.
thermal paper coating in the heat-sensitive ingredients are mainly two: one is a leuco dye or leuco dye; the other is a developer. This kind of thermal paper is also called two-component chemical type thermal recording paper.
Commonly used as leuco dyes are mainly: crystal violet lactone (CVL), fluoran system, leuco benzoyl methylene blue (BLMB) or spiropyran system of triphenylmethane phthalide system.
The commonly used dispersants are mainly: polyvinyl alcohol L-3266, polyvinyl alcohol GL-05, polyvinyl alcohol KL-03 (produced by Japanese synthetic chemistry).
The commonly used topcoat and undercoat additives are mainly: gohsefimer Z-200, polyvinyl alcohol T-350, polyvinyl alcohol N-300.
Commonly used as a color developer is mainly: para-hydroxybenzoic acid and its esters (PHBB, PHB), salicylic acid, 2,4-dihydroxybenzoic acid or aromatic sulfone and other substances.
thermal paper after heat leuco dye and chromogenic agent chemical reaction to produce color, so the use of thermal paper on the fax machine to receive the signal printing or direct use of thermal printer printing, graphics and text is displayed. Because there are many varieties used as leuco dyes, so the appearance of the writing color is different, there are blue, purple, black and so on.
