The principle of thermal paper

Thermal paper production principle is powder coated particles on plain paper base, composition is colorless dye phenol or other acidic substances, with thin film apart, under the condition of heat, melt film, powder mixed chromogenic reaction. Thermal paper on color's handwriting is not stable, easy to fade, cause it is difficult to identify the file content. Thermal paper were placed above 70 ℃ environment, thermal coating began to change color. The discoloration of reason from the composition of it. The thermal component of thermal paper coating are mainly two kinds: one kind is colorless dye or leuco dye; Another is the chromogenic agent. This type of thermal paper also referred to as the bi-component chemical type thermal recording paper.
 
Commonly used as a colorless dye is mainly: three alkyl benzene armour phthalide system of crystal violet lactone (CVL), fluorane system, colorless benzoyl methylene blue (BLMB) or substances such as screw pyran system.
 
Is commonly used as the main agent: para hydroxy benzoic acid and its esters (PHBB, PHB) 2 hydroxy benzoic acid, salicylic acid, 2, 4 - or aromatic sulfones material.
 
Thermal paper after heated colorless dye color react with chromogenic agent, so the use of thermal paper receives signals on the fax machine to print or direct thermal printer to print, graphic display. There are many ways to being used as a colorless dye varieties, appeared so handwriting has different color, blue, purple, black, etc.
 
Thermal paper factory,