Polyamide resins are made by condensation reaction of dimeric acid and diamine. Depending on the solvent polyamide resin is usually divided into co-solvent type and alcohol soluble type.
Co-solvent type polyamide resins are soluble in alcohol mixtures or mixtures of alcohols and aliphatic hydrocarbon co-solvents, which ensure excellent adhesion, pigment wetting and gloss, fast solvent detachment, water resistance, chemical resistance and low temperature resistance.
Co-solvent type polyamide resins are used in the manufacture of gravure plastic printing inks and paper inks. They have good adhesion to polyethylene and other substrates and are particularly suitable for printing on plastic films such as polyethylene packaging films and metal foil laminates. The ink made of alcohol-soluble polyamide resin has good adhesion, high gloss, low freezing point, solvent release and good compatibility with nitrocellulose, etc.