The choice of solvent
In the printing ink manufacturing process, in consideration of the overall solvent system of the ink volatility, to improve the printing ink solvent release and reduce the solvent organic solvent residue, the use of solvents are often several volatile mixed solvents.In the printing ink manufacturing process, the main organic solvents are toluene, butanone, cyclohexanone, ethyl acetate, butyl acetate, n-propyl acetate, isopropanol, etc., customers can adjust the volatility of the ink according to seasonal changes.
The choice of pigment
As a result of the market pigment grade difference, in polyurethane ink for the same resin manufacturers of the same pigment dispersion, ink stability and other aspects of the performance is often a big difference, so it is recommended that users according to their actual customer needs carefully choose pigment.
The selection of additives
Wax powder: in the production of polyurethane ink, the use of wax powder is often low molecular weight polyethylene wax, the relative molecular weight is generally 1000 ~ 6000, the organic solvent in the ink has a good solubility, and polyurethane resin affinity is good, at the same time has a good chemical stability.Mainly to increase the friction of the surface of the ink film, at the same time to properly alleviate the anti-viscosity of the ink itself.
Dispersant: a class of surfactant, mainly used for wetting pigment surface, shorten ink manufacturing time, is conducive to the dispersion of pigment, and sometimes appropriate to reduce the oil absorption of pigment.In the production of high concentration of ink, ink yield can be reduced to prevent the ink pigment particles agglutination and precipitation has a certain effect.
Polyurethane resin adhesion promoter: printing inks containing a large number of polar groups, BOPP, PE and so on nonpolar substrate surface even by corona surface treatment, surface tension in 38 dyne ~ 42 dyne, to improve the polyurethane ink on the substrate surface adhesion fastness, often need to add the appropriate ester titanate coupling agent or chlorinated polypropylene adhesion promoter.