Printing gravure

Publication gravure printing inks are commonly toluene-based in some countries, mixtures of toluene and aliphatic hydrocarbons were also used. Ready-made printing inks normally contain solvents in excess of 60% solvent and between 4 and 10% pigment. The solvent content makes it necessary to employ pigments with sufficient fastness to solvents i.e., pigments which do not recrystallize too much under the conditions of dispersion and processing. 

However, amine-treated pigments also have their problems. The treatment process affords dark red compounds which are easily soluble in toluene and appreciably enhance the tinctorial strength of the resulting printing ink (Sec. 2.4.1.4). The same pigment formulation, however, will be considerably less soluble and thus weaker in printing inks based on aliphatic hydrocarbons or in media which contain blends of toluene and aliphatic hydrocarbons. As the ink is printed on to the 

Curve 1 Pigment Yellow 12, Curve 2 Pigment Yellow 12, amine treated. 

The conditions to be met in decorative printing are particularly demanding. Decorative papers for gravure and flexographic printing are used to produce laminated plastic sheets. Pigment selection is a matter not only of the type of resin (melamine or polyester), but also a function of the processing method. 

Polyester sheets require pigments which are fast to certain solvents. A pigment that is used to color polyester dissolved in styrene must therefore be completely fast to both polyester and styrene monomer. In order to tolerate the diallyl ph-thalate process, which involves dissolving polyester in acetone, a pigment should be completely fast to acetone. 

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Sulfonamide groups can be introduced into phthalocyanines to make them soluble in alcohols and glycol ethers. Their main appHcations are transparent paints, flexo and gravure printing inks, wood stains, plastics, and ballpoint inks. This includes products Hke Solvent Blue 24 (Cl 74380),... 

Then three prints ate appHed by offset gravure printing using three carefliUy selected color inks. The panel is assembled into the furniture and finished with lacquers as in the standard process. 

Figure 12.10. Micrographs of devices fabricated using gravure printing technology. Left—shows the interdigitated transistor gate fabricated by an ink composed of nanoscale metallic particles. Right—Channel fabricated when using a silver-filled adhesive to print the transistor source and drain.

Fig. 14 Pigment Yellow 12 in a publication gravure printing ink based on metal resinate.

Fig. 37 Dispersion of 5% Pigment Orange 43 in a toluene-based gravure printing vehicle with a paint shaker. Effect of the dispersion time and the dispersion temperature on the depth of shade (left) and on the hue of the prints (right).

Fig. 45 Electron micrograph of an ultramicrotome-cut thin section of a nonirradiated gravure printed layer. Pigment concentration in the printing ink 4% Pigment Yellow 12.

Publication gravure printing inks apparently show elastic behavior at D = 105 s the modulus of shearing G is 103 Pa. This indicates that at high shear rates D, between 105 and 106 s gravure printing inks develop normal stress effects and thus show a hydrodynamic lubricating effect. These deductions are relevant to an... 

Fig. 86 Rheograms of publication gravure printing inks containing 15% pigment.

Security printing does not denote a particular printing method but an application sector in which one or several well-known printing methods are used, such as offset, letterpress and gravure printing. 

Preparation with aliphatic amines, on the other hand, may promote side reactions, converting portions of a pigment to compounds that are somewhat soluble in toluene. Toluene is the most important solvent for publication gravure printing inks. This preparative method reduces the viscosity of the printing ink. The pigment is thus partially converted to a soluble azomethine (Schiff s base), which is formed by reaction between the acetoacetic arylide and an aliphatic amine [5] ... 

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