In addition to the above-mentioned molecules being excited at a high energy level, it is also possible that under the action of a photosensitizer or an ultraviolet absorber, decomposition of photons (both photodecomposition processes), or activation of a part of a bond, generates an activating molecule (free radicals) ), Caused by the dual-polymerization or photocoupling reaction caused by coupling bridging, which has made the ink counterparts consensus. However, the use of non-absorbing polar UV inks may cause photon decomposition again, which will not be described here.
Achieve UV offset non-polar materials, to achieve adhesion fastness, change the low-temperature characteristics, can flow normally and avoid the fluctuation of the way of operation by varnish, the author after conducting research on the above issues found: most ink and non-polar printing The hydrogen bond value, PH value, free energy value, and surface tension value of the material are too large to change, that is, the overall structure of the UV ink UV lacquer is not changed. At Jiangsu Yizheng Tianyang Chemical Plant, Tianjin Lisheng Chemical Factory, Songzi With the support of the resin plant and other units, boldly adopting grafting, compounding (mixing) technology, using "value engineering", "orthogonality", and "backward algorithm", adding 0.25% of the city under the support of Mr. Li Xiang of Qingdao. The LJJ·TM additives sold by the company were introduced into the UV ink system. After being simply dispersed, with the cooperation of Qingdao China Daosheng Printing Co. The process is simplified, the cycle is shortened, the adaptability is expanded, and the quality is improved. We have learned that only by seizing the high ground of science and technology can we expand the printing and consumption space of non-polar flexible packaging printing media; only when occupying the beachhead of the market economy can we repeatedly emphasize that time is money and quality is life; only high quality and low value Based on printing inks, we can seize the opportunity to occupy the beachhead of the market economy; only if we have no people, I have excellent people, and people are new to me, can we capture the latest scientific and technological achievements at home and abroad from the market information feedback for me. Used.
Third, innovation and improvement of ideas 1. Green non-absorbing UV offset polar material inks, as the name implies, are based on different ink compositions and require adhesion, high flow, low cost, simple craftsmanship, and bright colors without the need for glossing.
We analyze the "ink manufacturing process" textbook (example formula design: 1 Polyol 25-45; 2 Polyol 20-40; 3 Propionic Acid 10-30; 4 Hydroquinone 0.05-0.2; 5-Toluene Phosphoric Acid 0.1- 2/Binder) Enumerated ink formulations (10% of colorant white 50-60%, color ink 15-25%; 20% of binder 40-70%; 3 adjuvant 0.01-20%) for analysis, not difficult to see The reason is that the system acid mixture is one of the causes of the photon decomposition process (molecular decomposition) under the action of a photoinitiator after the UV ink is formed into a film or a source thereof. In addition, we according to the current resin technical indicators: 1 viscosity 25-50 Pa · sec / 25 °C; 2 acid value of 20 or less; 3 color ≤ 10; ink technical indicators: 1 color near sample; 2 fineness 15-20μm; 3 Flow degree 20-35mm; 4 coloring power 90-110%; 5 viscous 15-25 (32°C); 6 impact strength (N·m) 29.4; 1 photo-setting time SI-3, etc. After the study, it was found that the location of fluidity has not been adapted to the requirements of modern high-speed web offset non-polar carriers.
For example, we have increased the styrene, which is an alkaline solvent, to improve its fluidity. However, after ultraviolet light curing, especially after the back exposure, the gloss is slightly poorer, and the second is that the friction ink film falls off into particles. The resin composition in the ink film system is small and overly brittle. On a large scale, the use of acid inks will increase the adherence of the printing ink film, but the above-mentioned failures have caused us to feel helpless at the moment and have interrupted several years of research. In order to break through the set of academic theories and jump out of the dead end of the environment and conditions, we focused on unsaturated resins (general term for resin materials made up of monohydric or polyhydric alcohols and dibasic or polybasic acids). The formulas and processes for resin binders and pigments and dyes (see Table 1 for details) abandon traditional practical loading methods and use compounding techniques to add additives. In the formula, we designed an inorganic pigment, an organic pigment, an extender pigment, a metallic powder fluorescent dye, etc. in terms of colorants, and also from the price, color, light and shade, alkali resistance, abrasion resistance, and in particular the curing of the ink. Characteristics, storage stability, surface reflectivity and wettability considerations.
1. The process flow of Wuhan resin-made link material first puts the resin into the reactor, and when it is heated to 120-130°C, it stops heating. When it drops to 120°C, the photoinitiator is thrown in and stirred, and then held down. 100 °C, put sensitizers and colorants, continue to reduce the temperature to 6o °C, the prepared auxiliary resin, hardener, plasticizer mixed into the kettle, evenly dispersed or rolled to fineness After the instant UV curing ink.
2. The process flow of Xi'an's resin-made linking material firstly adds benzoin into finely ground resin, raises the temperature to 12°C, stirs it well, and then heats it at 120°C for 20 minutes and then adds the hydroquinone when it cools to 80-60°C. After homogenously warming to 70°C to dissolve, cool down again at 60°C, add stannous chloride, stir well, and then reduce it to about 40°C. Add benzoin ethyl ether and mix well with poetry.
â–³: When used, it was called 100 g, and the temperature was raised to about 60C. Methacrylic acid (34.5 g in summer, 17.25 g in winter), vinyl acetate 4.5-22.5 g, and screen printing ink 5.5-11 g were added.
3, the performance and use of the main raw materials (1) photoinitiator and preservatives: benzoin, also known as benzoin ketones, benzoin, benzoyl methanol, bitter amaranth, phenyl hydroxy benzophenone, diphenyl hydroxy It is ethyl ketone. There are many kinds of photoinitiators, usually should take into account the curing properties, absorption spectrum, stability, color tone, permeability, odor, volatility, ion reactivity, corrosion, printing film expansion, etc., to ensure that the photoinitiator Stability is of primary importance.
(2) Sensitizer and catalyst: Stannous chloride, also known as tin dioxide.
(3) Auxiliary resin and cross-linking agent: Methacrylic acid, also known as α-methyl, is propylene, methacrylic acid.
(4) Plasticizer and stripper: Diester, also known as dibutyl phthalate.
(5) Heat Stabilizer and Inhibitor: hydroquinone, also known as Hyder, several pairs of Ni.
(6) Dispersant and Interfacial Adhesive: LJJTM, also known as interfacial adhesive.
(7) Auxiliary resin and cross-linking agent; vinyl acetate, also known as vinyl acetate.
(8) Crosslinker and diluent: styrene, also known as vinylbenzene.
(9) Auxiliary resin and cross-linking agent: Acrylic acid, also known as acid and vinyl formate.
(10) Anti-wear agent and ink additive: polyethylene wax. (To be continued)