Thermally sensitive coating is very important in the production of thermally paper
, the chemicals used in thermally sensitive coatings are generally composed of more than ten kinds of materials in a certain proportion.
But each company's thermal paper coating formula has different patents, and not the same. The following is a brief introduction of the basic proportion of coating.
There are at least these components in thermal paper:
(1) colorless dye, accounting for a few percent, the dye variety is very large, the most commonly used is fluorane compounds. Such as: 3 two ethyl amino a 7 a neighboring chlorobenzene fluorane, etc.
(2) colorant, accounting for less than 20%, commonly used bisphenol A, para hydroxybenzoate. The common colorants are: p-phenyl phenol; Methylene naphthol salicylate; Aromatic sulfonic acid; Aromatic sulfide; 2,4 dihydroxybenzoic acid.
(3) Sensitizing agent, accounting for less than 10%, such as benzene sulfonate amide compounds.
(4) filler, accounting for less than 50%, commonly used is calcium carbonate (fine particles). Effect: improve the paper opacity, improve the contrast between imaging and background color.
(5) adhesive, less than 10%, such as polyvinyl acetate. Function: the coating has good surface strength and printing performance, the adhesive also forms a colloid protective film between the dye and the colorant at the same time, so that the two are isolated to prevent premature reaction.
(6) stabilizer, accounting for a few percent, such as terephthalic acid diphenyl.
(7) lubricant, accounting for a few percent. It is candle sex material commonly, can prevent hot head to stick smudge.