A brief introduction to the composition of gold and silver printing inks

Like other inks, gold and silver inks are mainly composed of pigments and linking materials. Simply put, gold inks are made of gold powder and gold transfer oil. Silver inks are made of aluminum powder and silver adjusting oil. Made.

Pigment

The pigment in gold ink is gold powder, which is actually a powder made of copper and zinc alloy. The content of zinc in gold powder is generally about 8% to 30%, and the zinc content is between 8% and 12%. The gold color of the ink is reddish, and it is customarily referred to as red gold. The color of gold ink with a zinc content of between 20% and 30% is partial green. It is generally called the green gold, and is called between the red gold and the green gold. For the red gold. In gravure printing, gold powder with 800 mesh is generally used for blending gold ink, and the surface of gold powder particles are mostly coated with surfactants, which can be well combined with resin binders. Silver powder is actually aluminum powder and is composed of 65% aluminum flakes and 35% volatile hydrocarbon solvents. Aluminum pigments have a small specific gravity and are easy to float in liquids. What is used in the gravure silver ink is the floating silver powder that has floating ability in the link material. The silver ink generally uses 400 to 1000 mesh silver powder. If a silver ink is printed on a large area, a lower mesh silver powder may be used. For example, a 400-point silver powder is used to modulate silver ink and has a high metallic luster after printing.

2. Binder

The linking material used in gold and silver inks is a special varnish, which is generally called gold transfer oil or silver regulating oil. The main components are oil, resin, and organic solvent auxiliary materials.

The binder of offset ink should meet the following conditions:

1 must have sufficient viscosity to combine well with gold powder or silver powder.
2 The transparency must be high, and it cannot influence the hue of gold and silver ink.
3 The acidity of the transferred oil or silver oil is low, otherwise it will cause chemical reaction of the powder or silver powder.
4 gold transfer oil or silver transfer oil should also have quick-drying and fast fixation, to prevent the back of the gold ink or silver ink prints dirty.

3. Additives

Adding a small amount of bright light or transparent yellow in the metal can enhance the ink affinity and transferability of the gold ink; adding a small amount of red dry oil to the golden ink in winter can speed up the drying rate; add stearic acid amide surface activity when adjusting the ink The agent can fully wet, disperse, and float the gold powder in the binder. Reduce the stencil and ink accumulation in the ink transfer process. Adding a small amount of bright light in gold ink can dilute the golden ink while increasing the brightness and viscosity, reducing the gold ink accumulation and improving the fluidity.