Application of the hottest UV printing ink on film

The application of UV printing ink on thin films (II)

due to the absorption of light with different intensities at different wavelengths, the absorption spectrum formed has high sensitivity (photochemical reaction), which can be quickly dried almost when it can be combined and cured without seeing. It is more able to design a complete set of full automation (from offset printing to curing), and can also adapt to trace Trace analysis and dynamics research: from light source to light intensity (voltage level will not be the same), from lamp type to output spacing (the spectral distribution of emission is also different); From the thickness of the ink film (including the content of photosensitizer in the system) to the length of the wavelength of the ink pigment (the more transparent and thinner the ink film, the shorter the wavelength; the greater the light energy, the faster the drying); From the surface tension, hydrogen bond force and free energy of the substrate to the inspection of its adhesion, etc

in addition to the high-energy position of the above molecules after excitation, it may also lead to photon decomposition (i.e. photodegradation process) under the action of photosensitizers or UV absorbers, or a part of the bond will generate activated molecules (free radicals) after opening the bond, causing the polymerization of double bonds or the optical crosslinking reaction such as coupling bridging, which has been recognized by ink peers. However, the use of non absorbable polar UV ink may lead to photon decomposition again, which will not be repeated here

realize UV offset non-polar materials, achieve adhesion fastness, change low-temperature characteristics, be able to flow normally and avoid the fluctuating operation mode of polishing oil. After studying the above problems, the author found that: most inks and non-polar substrates (an increase of 8.92% year-on-year; realized profit of 118.286 billion yuan 3) hydrogen bond value, pH value, free energy value The difference in surface tension value is too large. In order not to change the overall structure of UV varnish of UV ink, with the support of Jiangsu Yizheng Tianyang chemical plant, Tianjin Li biochemical plant, Songzi resin plant and other units, the grafting and compounding (mixing) technology is boldly adopted, and the "value engineering", "orthogonal method" and "inverse method" are used. With the support of Mr. Li Xiang in Qingdao, 0.25% of commercially available LJJ · TM additives are added and introduced into the UV ink system. After simple dispersion, With the cooperation of Qingdao Zhonghua Daosheng Printing Co., Ltd., after starting printing, it can achieve the gratifying effect that it can adhere firmly without glazing - less materials, simplified process, shortened cycle, expanded adaptability and improved quality. We learned from it that only by seizing the commanding height of science and technology can we expand the printing consumption space of non-polar flexible packaging printing carriers; Only by occupying the beachhead of market economy can we repeatedly emphasize that time is money and quality is life; Only based on high-quality and low-value printing inks can we seize the opportunity to occupy the beachhead of market economy; Only by doing so can we capture the latest scientific and technological achievements at home and abroad from market information feedback for our own use

III. ideas for innovation and improvement

1. Green non absorbable UV offset polar material ink, as the name suggests, is composed of different inks, and requires adhesion, high fluidity, low cost, simple process, bright color and no glazing

we analyze the ink formulas listed in the textbook "ink manufacturing technology" (example formula design: ① uncontrolled polyol 25-45; ② polyol 20-40; ③ propertic acid 10-30; ④ hydroquinone 0.05-0.2; ⑤ p-toluene phosphate 0.1-2/binder) (① colorant white 50-60%, color ink 15-25%; ② binder 40-70% from the demand comparison of traditional industry and high and new technology; ③ auxiliary agent 0.%) Through detection and analysis, it is not difficult to see that the acidic mixture of its system is one of the reasons for the problem of photon decomposition process (molecular decomposition) in the process of UV ink film formation or after source formation under the action of photoinitiator. In addition, according to the current resin technical indicators: ① viscosity 25-50 PA · s/25 ℃; ② Acid value below 20; ③ Color ≤ 10; Technical indicators of ink: ① similar color; ② Fineness 15-20 μ m； ③ Fluidity 20-35mm; ④ Coloring power 90-110%; ⑤ Viscosity 15-25 (32 ℃); ⑥ Impact strength (n · m) 29.4; ① After careful and repeated research, it is found that the positioning of fluidity can no longer meet the requirements of modern high-speed offset non-polar carrier. For example, we used to increase styrene, a solvent with both alkaline properties, to improve its fluidity, but after UV curing, especially after back exposure, the gloss was slightly poor, and the granular shedding of the ink film was caused by friction - the resin composition in the ink film system was small and too brittle. On a large scale, acid ink will improve the adhesion of the printing ink film, but the occurrence of the above failure, we felt helpless for a moment, so we interrupted the research topic for several years. In order to break through the frame set by the current academic theory and jump out of the dead end of environment and conditions, we focus on unsaturated resin (the general name of resin substances formed by the condensation of monobasic or polyol and binary or polybasic acid), and successively set the formula and process of resin binder and color and dye coloring (see Table 1 for details), that is, we abandon the traditional practical loading method and adopt the additive method of compound technology. In the formula, we have designed inorganic pigments, organic pigments, physical pigments, metal powder fluorescent dyes, etc. in terms of colorants, we also consider the price, color, shade, alkali resistance, wear resistance, especially the curing characteristics, storage stability, surface reflectance and wettability of the ink. (to be continued)