Ink is a colorant for printing. It is a kind of fluid substance that has a certain viscosity because the pigment particles are evenly dispersed in the binder.
1. Composition of ink
The ink consists of pigments, binders, fillers, and additives.
(1) Pigments
Pigments play a colorizing role in the ink, which in turn has a direct effect on some properties of the ink.
The pigment is a color, black or white highly disperse powder that is insoluble in water and organic solvents. According to its source and chemical composition, it is divided into organic pigments and inorganic pigments.
1 Inorganic pigments are oxides of non-ferrous metals, or some metal-insoluble metal salts. Inorganic pigments are further divided into natural inorganic pigments and artificial inorganic pigments. Natural inorganic pigments are mineral pigments.
2 Organic pigments are colored organic compounds and are also divided into natural and synthetic categories. Nowadays, synthetic organic pigments are commonly used. There are many varieties of organic pigments, and the colors are relatively complete. The performance is superior to that of inorganic pigments.
Dyes are organic compounds which are soluble in water and sometimes also dissolved in organic solvents. Insoluble color precipitates, called lake pigments, can be prepared from certain dyes for the production of printing inks.
The requirements for the pigments used in printing inks are quite high, especially the color, dispersion, light resistance, transparency, etc., and the hue of color pigments is required to be close to the spectral color, the saturation should be as large as possible, and the magenta, cyan, and yellow colors used for the three primary color inks should be used. The transparency of the pigment must be high. All the pigments should not only be water-resistant, but also should be quickly and evenly combined with the binder. The oil-absorbing ability of the pigment should not be too large. The pigment is preferably resistant to alkali, acid, alcohol and resistance.
(2) Connection material
The binder is the main component of the ink, serves to disperse the pigment, imparts proper sticking, fluidity and transfer properties to the ink, and serves to fix the pigment on the surface of the print after filming by printing. The connecting material is commonly known as varnish.
The binder can be made of various materials, such as various dry vegetable oils, most of which can be used to make binders for inks, mineral oils can also be made into binders, solvents and water, and various synthetic resins can be used to make them. The binder.
The rheology, viscosity, neutrality, acid value, color, water resistance, and printing performance of the ink are mainly determined by the binder. The same pigment, using different binders, can be used to make different types of inks; Use different colors. The ink produced is still the same type of ink, because it can not change the fundamental performance of the ink, so the quality of the ink is good or bad, but depends on the pigment, but mainly depends on the connection material.
(3) Packing
The filler is a white, transparent, translucent or unpleasant powder substance. Mainly from the filling, filling the pigment part, the appropriate use of some filler, can reduce the amount of pigment, reduce costs, but also can adjust the properties of the ink, such as thick, fluidity, etc., but also improve the flexibility of formula design.
(4) Additives
Additives are some of the materials added to improve the performance of the ink itself during the manufacture of the ink, as well as during printing. The inks formulated according to the basic composition still cannot satisfy the requirements in certain characteristics, or they must be added with a small amount of auxiliary materials when they cannot meet the requirements for printing use due to changes in conditions.
There are many additives, such as: desiccant, desiccant, diluting agent, remover, plasticizer and so on.
2 kinds of ink
The variety of inks can be classified by various methods:
(1) According to the printing method
1 According to the layout type: Letterpress, lithographic, gravure, photogravure, screen printing, etc.;
2 According to the printing methods: Offset, direct printing and other inks.
(2) Divided by printing materials
Divided by printing materials: paper, metal, plastic, cloth and other inks.
(3) divided by dry form
1 according to the drying mechanism: penetration drying type, oxidation polymerization type, volatile drying type, photo hardening type, thermosetting type, cooling and curing type ink;
2 According to the drying method, there are: natural drying type, hot air drying type, infrared drying type, ultraviolet drying type, cooling and drying type ink.
(4) According to ink characteristics
1 divided by color: yellow, red, blue, white, black, gold, silver, gold powder, fluorescent color, pearl color, etc.;
2 divided by function: magnetic ink, anti-counterfeiting ink, edible ink, foaming ink, aromatic ink, recording ink, etc.;
3 according to the resistance: light resistance, heat resistance, solvent resistance, abrasion resistance, alcohol resistance, chemical resistance and other inks.
(5) According to ink composition
1 according to the raw materials are divided: dry oil type, resin oil type, organic solvent type, water type, paraffin type, ethylene glycol type ink;
2 according to the form: gelatinous, liquid, powdered ink.
(6) by purpose
Divided by purpose: news inks, book inks, packaging inks, building materials inks, trademark inks.
