Aluminum foil for packaging and printing (hard aluminum foil of 0.2mm to 0.25mm and soft aluminum foil of 0.07mm to 0.09mm) is used for coating and printing. It is also known as varnish and OP protector. This article focuses on the description and introduction of the material composition, formulation design, and application results of the five types of ambient-curing, high-temperature-curing, and light-curable three types that have been developed entirely using domestically produced raw materials. The main task of aluminum foil coating The main task of aluminum foil varnish is to coat semi-finished products that have been printed in all single-print or multi-color overprinted packages and then apply a protective layer. Its purpose is to further promote the surface gloss of packaging and printing products, aesthetics, acid, alkali, etc., while protecting the printed ink film. Not only increases the surface hardness of printed products, but also has a certain degree of flexibility, but also can improve the packaging printing product quality rate, enhance the high value-added goods packaging. From the use of aluminum foil varnish, we already know its main task. However, people use only room-temperature curing varnishes for food packaging in their scope of application. In particular, in the past three years, the fashionable beer packaging (top) packaging labels have become colorful. The general high temperature 121 to 160°C coating oil is used for cooking beverage cans, cigarette packs and pharmaceutical packaging. With the implementation of the National Drug Packaging Container (Materials) Standard to the present (June 1, 2004), the traditional test based on GB12255-90 only has specifications, volatiles, adhesive coating amount difference, heat seal strength, protective layer Five items, such as heat resistance, were replaced by YBB00132002 (composite film for pharmaceutical packaging, general rule for bags). This not only marks the convergence of China's packaging products, especially pharmaceutical packaging products, with international standards, but also marks the end of traditional coating products. The advent of eco-friendly aluminum foil varnish marks the beginning of new varnish products. The basis for the development of its products: The first is: (1) identification of infrared spectrum; (2) appearance; (3) barrier properties (water vapor and oxygen); (4) mechanical properties; (5) heat sealing strength of composite bags (double and multiple layers); 6) Solvent residue volume; (7) pressure resistance of the bag (three sided seals and other bags); (8) drop performance of the bag (bag and total mass of the contents and drop height); (9) dissolution test: 1 Heavy metal; 2 Easily oxidized; 3 Non-volatile; (10) Microbial limits (general composite membranes, bags, composite membranes for external use, bags, etc.) (11) Abnormal toxicity. The second is: YBB00132002 stipulates that (1) composite film means a film formed by combining various plastics with paper, metal or other plastics through a combination of adhesives, and its thickness is generally not more than 0.25 mm; (2) the composite bag system passes the composite film through The bags made by the heat-sealing method can be divided into three-side sealing bags, middle sealing bags, organ bags, self-standing bags, zipper bags and the like according to the form of bags. In addition, the classification, barrier properties, mechanical properties, drop performance, microbiological limit indices, and dimensional deviations of the composite film are expressly specified. The author revolves around environmental protection and integration with the international market. In addition to physical measurements, the author also increased the measurement of physical and chemical indicators. At the same time, since the total residual amount of solvent in the past was 30 mg/m2, it was changed to 10 mg/m2 and the benzene residual limit was 3.0 mg/m2. Combined with the first titration with sodium thiosulfate (0.01mol/L) titration to near the end, the added starch indicator liquid 0.25ml, continue to titrate to colorless, and the other water blank solution with the same operation, the difference between the two consumption titrant Over 1.5ml of harsh restrictions. Add coating oil to 180-250°C, 10 seconds without discoloration, no fading, no fading, no sidelight (because of heat and light, not only due to high softening point, but also due to conductivity) . At the same time should also comply with the following technical requirements: (1) good color retention performance, do not migrate after a certain temperature drying graphics, no yellowing, no discoloration, or ink ink film does not fall off; (2) have a certain degree of brightness, fastness , Adhesive tape does not peel off; (3) It should have certain affinity with white printing ink or color ink and base oil; (4) High solid content, small viscosity, high transparency, especially smooth and smooth Good; (5) After coating, it can resist die-cutting, does not hurt the knife, and can withstand mechanical impact such as embossing and punching. Basic composition of aluminum foil varnish The basic composition of environmental-friendly aluminum foil packaging varnish is: resin, solvent, filler, and auxiliary agent. At present, aluminum foils are mainly coated with thermoplastic resin in the coating system of the varnish, while the general high-temperature (120-160°C) aluminum foil varnish system is made of thermoplastic resin, and a small amount of thermosetting resin or amphiphilic resin is added. In the high temperature (180-250°C) aluminum foil packaging varnish system, thermosetting resins and amphoteric resins are used. The choices of the resins include: acrylic resin, nitrocellulose, polyamide resin, natural rosin modified resin, phenolic resin, organic silicon resin, polyketone resin, amino resin, and the like. Its solvent ratio is mainly alcohol, ester, ketone, benzene supplemented. Auxiliaries include leveling agents, slip agents, trace amounts of light stabilizers, and thermal stabilizers. At present, regarding normal-temperature-cured aluminum foil glazing resins, in addition to the above-mentioned introduction, most of the polyamide resins selected from the group consisting of higher softening point polyamides and amphoteric nitrocellulose or polyketone and terpene resins are formed around completely non-toxic. There are also vinyl compounds such as nitrocellulose used to prevent sticking at a certain temperature. The selection and compatibility of the solvent is based on the small odor. The multiple solvent mixture is used to achieve the evaporative gradient balance of the coating oil during the coating process (both inside and outside). As for the choice of additives, the main advantage is to make sure that the same quality of coating oil can reach different coating areas (amount). At the same time, the cost is lower and the control is lower. Total residual solvent and benzene residues. For example, the composition (formulation) of the mixed solvent: acetone 47.14, ethyl acetate 35.35, industrial ethanol 17.51, as a thinner for the coating oil. The advantages of adopting ethyl acetate solvent more than usual are: the solvent odor of aluminum foil packaging printing is small, the solvent residue is small, the film formation and drying speed is fast, the attachment fastness is good, the glossiness of gloss oil is high, and the cost of thinner solvent is low. In general high-temperature 121-160 °C or even 180 °C aluminum foil coating Varnish is modified rosin ester with nitrocellulose or high-softening point polyamide resin or nitrocellulose by adding amino resin and other components. It is also composed of a high softening point thermoplastic acrylic resin added with a vinyl chloride resin. Now high-temperature (180-250 °C or even higher polish) aluminum foil coating varnish is composed of a thermosetting resin grafted with amphoteric resin and silicone resin. Stabilizers are often introduced to control easy oxides. In order to control the generation of anomalous toxicity, the words O, H, and Cl appear in the resins, solvents, additives, and even dyes and dye molecules. The theoretical theory of oxides is: (1) Elements and oxidized compounds. As used herein, an oxide refers to an ionic or covalent oxide formed by the incorporation of oxygen as a single atom. In addition, there are peroxides, superoxides, ozonides, organic oxides (eg, ethylene oxide), etc., and the same element may have oxides having different valences. Such as: sulfur dioxide SO2 and sulfur trioxide SO3; cuprous oxide Cu2O and copper oxide CuO, preparation methods are: 1 simple substance or compound in the air or pure oxygen combustion, can get common oxide; 2 in the red heat temperature, Oxidation of elemental to oxides with water vapor; 3 Oxidation of certain elements to oxides with nitric acid as an oxidant; 4 Dehydration of hydroxides or thermal decomposition of carbonates, nitrates; 5 Addition of alkali to salt solvents Removal of precipitated hydroxides or oxides, followed by dehydration drying; 6 Reduction of oxides in highly oxidized form with reducing agents gives oxides in low oxidation states. (2) Metal or non-metal and oxidized compounds. The same element can have several oxides with different valences. For example, carbon monoxide CO and carbon dioxide CO2 and copper oxide CuO; iron monoxide FeO, ferric oxide Fe2O3 and Fe3O4 ferric oxide etc. Oxides can be classified into acidic oxides, basic oxides, amphoteric oxides, and inert oxides. In order to achieve a firm adhesion, in addition to the strict solubility, hydrogen bonding force, surface tension, boiling point, volatilization rate, and evaporation rate in the product system, appropriate amounts of wetting additives are added to facilitate the coating and printing of graphics. Ink film affinity. Its purpose is to bypass the technical barriers and achieve scientific and standardized aluminum foil coating (protective agent). Aluminum foil varnish production process Raw materials, solvent input, resin injection, dissolving, dissolving, auxiliary additives, scraping, and testing were used. Aluminium foil coating recipe examples: High Temperature Aluminum Foil Varnish (Formula One) Test Report Remarks: 1. Production of the product at 160°C and 200°C, respectively (batch coating, see Table 1), of which 2 are comprehensive records; 2. Venue: Henan Kaidi Drug Packing Material Co., Ltd. 3. Time: morning of June 6, 2004 (the same test date); 4. Test basis: GB12255-90; 5. The aluminum foil adopts 0.024×140mm prime aluminum foil (PTP); 6. Pharmaceutical aluminum foil inspection records (see Table 1). Table 1 Medical Test Record 1. Determination of volatiles Take 100mm×100mm two pieces Index: ≤4mg/0.02m2 Weight before drying (mg) 1109.30 Weight after drying (mg) 1109.30 Volatile matter (mg/0.02m2) measurement result 0.20 qualified 2. Varying the coating amount of coating Take 100mm×100mm five pieces weighing The difference in the weight of the varnishing oil is the coating amount and the average value is calculated. The difference between the coating amount and the average value of each sheet is the difference in the coating amount. Indicator: 12.5% Original weight (mg) 1547.330546.603554.504549.455552.10 Remove the varnish weight (mg/m2) 1531.702530.803538.204533.405535.90 Coating weight (g/m2) 115.60215.80316.30416.05516.20 The average amount of coating (g/m2) 15.99 The difference in the amount of coating measurement results 1-2.43% 2-1.18% 31.93% 40.37% 50.31% qualified Heat seal strength index: ≥5.88N/15mm measurement result evaluation 10.10 pass Protective layer heat resistance index: 200 °C, 0.2Mpa no obvious adhesion measurement results No qualification The explanation is: The author has successively dried the high temperature resistant coating oil (Formulation 1-5) in Zhenjiang Jiangzhou Pharmaceuticals Packaging Co., Ltd. in Jiangsu Province at 180-250°C for 3-8 seconds, then it is easy to oxidize. The theoretical indicators of the material were measured four times and the results were: Formula 1 was 0 ml, Formula 2 was 0.7 ml, Formula 3 was 0 ml, Formula 4 was 0.8 ml, Formula 5 was 0.7 ml (The above is the difference between the two consumed titrants. number). In addition, the author uses high-temperature coating oil to add colorant (dye, color paste) as a general aluminum foil packaging printing ink and high-temperature aluminum foil packaging printing ink for the trial printing results, the printing ink film can reach YBBOO132002 requirements Testing requirements. And can be comparable with DIC's products, and the cost is only two-thirds of DIC. Conclusion With the development of automatic, labor-saving, high-speed, high-precision, high-quality aluminum foil packaging printing and coating varnish (protective agent), aiming at the emergence of the "horizontal convergence" effect of aluminum foil varnish on the market, high cost and residual harmful belts The disadvantages of the products came out one after another. In addition, there was no agglomeration effect. The technical level of Varnish and the level of the product could not be effectively improved. Looking at the global market economy integration, quality and quantity should be said to be two sides of a coin. Because today's scientific theory has not only created new packaging and printing materials, but also created a new product of aluminum foil packaging and printing varnishes, but also created a new round of knowledge of scientific basic theory updates. Only by weighing the advantages and disadvantages in the market competition can we promote and apply domestic aluminum foil varnish products to the limit; only the pre-sale product investigation, introduction, and post-sale application technology terminal tracking service can be accepted by domestic and international packaging printing users. The favor; Only with advanced science, can we guide China's aluminum foil packaging (printing) Varnish products technical progress in a long-term and effective way!