High tech trend of the hottest ink development

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The high-tech trend of ink development

as people have higher and higher requirements for the quality of printed matter, it requires that the quality of ink should also be improved in order to improve the quality of printed matter. Therefore, using high technology to develop ink manufacturing industry is the development idea of keeping pace with the times. After the development of recent years, the high-tech trend of ink has become increasingly prominent. This paper discusses the high-tech trend of ink development

I. environmental friendly ink

ink is the largest pollution source in the printing industry at present, and the annual output of ink in the world has reached 3million tons. Every year, the global emission of organic volatile compounds (VOC) pollution caused by ink has reached hundreds of thousands of tons. These organic volatiles can form a more serious greenhouse effect than carbon dioxide, and will form oxides and photochemical smog under the sunlight, seriously polluting the atmospheric environment and affecting people's health. In addition, the organic solvents, heavy metals and other harmful ingredients of ordinary inks used in the packaging and printing of food, children's toys and so on will also directly endanger the health of consumers and contacts. Moreover, with the growing voice of environmental protection, as the main part of green printing, the environmental protection requirements of ink are also increasing. It can be said that environmental protection ink is the first consideration for the development of ink in the future

to make the ink meet the requirements of environmental protection, we should first change the composition of the ink, that is, use environmental friendly materials to prepare new ink. At present, environmental protection inks mainly include water-based inks, UV inks, biological inks, soybean oil inks and some alcohol soluble inks

1. Water based inks

the solvent of water-based inks is water, not organic solvents. Compared with ordinary inks, it significantly reduces VOC emissions in the process of use, can prevent air pollution, is not easy to burn, has stable inkiness, bright colors, does not corrode plates, is simple to operate, has convenient prices, has good post press adhesion, strong water resistance, and dries quickly. Therefore, it is especially suitable for food, beverages, drugs and other packaging and printing materials. It is a world recognized environmental friendly printing material, It is also the only printing ink recognized by the American food and drug association among all printing inks at present. At present, 40% of plastic printing in the United States uses water-based ink, and other economically developed countries, such as Japan, Germany, France, use more and more water-based ink in plastic film printing. In June, 2004, the UK legislated to prohibit solvent based inks from printing food films. According to relevant information, in the United States, water-based inks that meet the VOC regulations must have a volatile component ratio of less than 25% and a moisture content of more than 75% in the use state; 3. Mechanical fatigue spring testing machine TPJ series features: the ink with less water content in use, the nonvolatile component is more than 60% of these two standards. Water based inks are generally used for printing paper products and paper plastic composite products

2. Soybean oil ink

this ink is based on 100% soybean oil, and the VOC component is 0. It can effectively prevent air pollution, improve the environment of the printing workshop. It is bright in color, has excellent machine stability and good post press processability, and has a large tolerance for paper. At the same time, when printing with this oil ink, the printed matter has a good deinking effect, which is conducive to recycling, and has typical environmental protection characteristics. At first, the drying speed of this kind of ink was relatively slow due to the use of plant-based materials. Now, Shanghai DIC has developed the "CLS drying system" technology [1], which can promote the rapid film formation of the ink layer, so that soybean oil ink has better dryness and friction resistance than ordinary ink. 3-4 color overprint can also show the fixation better than ordinary ink, and can form a solid, wear-resistant upper floor of ink operation

3. UV ink

UV (ultraviolet curing) ink refers to an ink that uses ultraviolet light of different wavelengths and energies to polymerize the monomers in the ink binder into polymers under ultraviolet irradiation, so that the ink forms a film and dries. UV inks also belong to inks. As inks, they must have bright colors (except for special cases), good printability, and appropriate curing and drying rate. At the same time, the ink film is required to be strong and tough, and the import and export volume of all kinds of paper accounts for no more than 20%. It has good adhesion, and has the characteristics of wear resistance, corrosion resistance, weather resistance and so on. It has similarities and differences with traditional inks, as shown in Table 1

it can be seen from table 1 that UV ink is an ink without solvent, with fast drying speed, good gloss, bright colors, water resistance, solvent resistance and good wear resistance. At present, UV ink has become a mature ink technology, and its pollutant emission is almost zero. According to statistics, the annual output of UV ink in Japan is about 1 60000 tons, about 1 in Europe 80000 tons, about 1 in North America 90000 tons. It should be noted that the water-based UV ink in UV ink is a new research direction in the field of UV ink at present. Because the viscosity of the prepolymer in ordinary UV ink is generally very large, it needs to be diluted with active diluent, and the currently used diluent acrylate compounds have varying degrees of skin irritation and toxicity. Therefore, while developing low viscosity prepolymers and low toxicity diluents, another development direction is to study water-based UV ink, that is, using water and ethanol as diluents. Fortunately, water-based UV ink has been successfully developed, It has been applied in some printing enterprises

4. Biological ink

biological ink is an ink made by biotechnology. It uses natural materials to show complex functions that non biological materials cannot easily obtain. Next, take bacteriorhodopsin as an example to explain its color development principle. Bacteriorhodopsin is a protein in the purple cell membrane of halophilic bacilli called halophiles, which grows in saline marshes. The purple source of this cell membrane is called bacteriorhodopsin component of the optic membrane. The amine acid in the cell membrane channel is firmly bound to the optic membrane, while the dissolved optic membrane is not bound to the amine acid and appears pale yellow. When two groups of lasers with different wavelengths are alternately irradiated on this protein molecule, this protein molecule can be converted back and forth between the purple structure and the yellow structure. Its film can also change its color according to the conversion of external electric field. In conventional bacteriorhodopsin, under the action of different electric fields, it will change from blue to light yellow. A display plate can be made by clamping the protein film into a transparent plate with a large number of electrodes. When an appropriate voltage is applied to different parts of the film, a page of manuscript or an image can be "written". Like ink, the image on bacteriorhodopsin display plate can also be seen in ordinary light. At present, the main difficulty faced by the whole research work is the need to use hundreds of volts of electric field to stimulate its color transformation. Researchers are working hard in this field and hope to make a breakthrough

5. Electron beam curing ink

electron beam curing ink is an ink that can quickly change from fluid to solid under the irradiation of high-energy electron beam, also known as EB ink. This kind of ink has the advantages of energy saving, solvent-free composition, solvent-free volatilization, no pollution to the environment and substrate, small curing space, fast processing speed, high output, small dot expansion rate, good imprinting brightness, wear resistance and chemical erosion resistance, so this kind of ink has been greatly promoted and applied in recent years

in addition to the above-mentioned representative environmental protection inks, many other new environmental protection inks are being studied and developed. It is believed that in the near future, there will be more and more varieties of environmental protection inks

second, anti-counterfeiting inks

the impact of fake and shoddy goods on the current market has become an international public hazard. The anti-counterfeiting products obtained by adding special functional materials (such as fluorescent materials, thermochromic materials, etc.) to ordinary printing inks for printing have the characteristics of low cost, convenient inspection and large market capacity. The anti-counterfeiting ink has the following anti-counterfeiting characteristics:

first, it adopts mechanical methods (force deformation, force heating, force phonation, etc.), such as force discoloration anti-counterfeiting logo. The outer layer of its special functional material is micro capsule [2], and the inner layer is filled with dye, which is mixed and printed with ordinary ink. During inspection, it only needs to exert strong pressure on the surface of the logo. Due to external force, the capsule breaks and releases dye, and the color changes immediately, Any choice of capsule dye color can obtain a variety of anti-counterfeiting effects

the second is to adopt thermal methods (thermochromic, thermochromic luminescence), such as adding thermochromic materials to ink. If the ambient temperature changes, the color will change accordingly to achieve the anti-counterfeiting effect

the third is to use electrical methods (electrochromism, electroluminescence), such as electrochromic ink, which adds some functional materials (such as tungsten trioxide, conductive polymers, etc.) to the ordinary ink. When the DC voltage acts on it, the structure of the functional materials changes, which will change the appearance color of the ink

fourth, use optical methods (photochromism, photoluminescence, invisible color change) to print invisible or colored anti-counterfeiting graphics and texts on corresponding materials. For example, the fluorescent ink coated on the base of banknotes adds fluorescent materials to ordinary inks. When irradiated by ultraviolet light, it will radiate visible light to achieve the purpose of anti-counterfeiting

fifth, according to the needs of customers, adopt the anti-counterfeiting ink formula with special commodity brand, and use the anti-counterfeiting ink products with strong uniqueness and characterization to achieve the purpose of protecting products

III. electronic ink

electronic ink contains charged liquid ink particles, which makes it possible to electronically control the position of printing particles in digital printing. It has extremely small particles (1 - 2 microns), which can make printing achieve higher resolution and smoothness, sharpen image edges, and form extremely thin image layers. At the same time, when the electronic ink is transferred to the substrate, it immediately dries without emissions, and the pigment particles of the electronic ink are dispersed in the plastic resin, which will prevent the chemical components of the pigment from being oxidized or affected by moisture, and will not fade under light irradiation

IV. application of nanotechnology in ink

nanotechnology is a high-tech that was born and rose rapidly in the late 1980s. Its basic meaning is to understand and transform nature in the nano scope, and create new substances and change and enhance the functional characteristics of original substances through direct operation and arrangement of atomic and molecular motion laws and characteristics. This means that people can produce extremely pure materials and colorful new products. At present, the use of modern science and technology, in the manufacturing process of ink to be replaced in time, add a small proportion of nano pigments such as 3% ~ 5%, which can improve the masking rate, saturation, optical rotation resistance, water resistance and other problems of ink. Nowadays, nano inks are widely used, such as nano inkjet inks, coatings, photoelectric displays, etc

source: Guangdong Printing

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