Preparation method of long-service-life two-dimensional code label for outdoor atmospheric environment

[0019] Example 1

[0020] Select 304 stainless steel, use laser engraving technology (laser repetition frequency is 20 kHz, engraving linear speed is 400 mm/s) to process the two-dimensional code pattern on the surface of the stainless steel, and then apply UV metal ink and ink to the two-dimensional code pattern part After curing, before coating the varnish, the surface of the QR code label is treated with decontamination and degreasing, pickling, and water washing followed by drying. The decontamination is washed with absolute ethanol, and the degreasing liquid is 30g/L NaOH, 50g/ L Na 2 CO 3 , Soak for 5min at room temperature; pickling solution is 40g/L HCl, 160g/L HNO 3 , Soak for 10 minutes at room temperature, rinse with distilled water, and quickly dry with a hair dryer. Finally, coat the entire label surface with a layer of 100μm high weather resistance and corrosion resistance modified acrylic polyurethane varnish, the modification method is to add 1wt% benzene And triazole. The appearance of the QR code label is as figure 1 As shown, the long-life two-dimensional code label of the present invention still maintains a clear and effective two-dimensional code pattern after being coated with two layers of ink and varnish. According to GB/T 16422.2-2014 "Plastic Laboratory Light Source Exposure Test Method Part 2: Xenon Arc Lamp" as the test standard, the prepared two-dimensional code label is subjected to a xenon lamp aging test with a test cycle of 2528h. After the test, the two-dimensional code The label looks like figure 2 As shown, the long-life two-dimensional code label of the present invention has a discoloration level of 0 after the 2528h xenon lamp aging test, the two-dimensional code pattern is clear and effective, the impact strength retention rate is 83.4%, and the hardness decrease is 11.7%. After 720h salt spray test, the QR code pattern is clear and effective, such as image 3 Shown; the impedance measured by electrochemical test is 4.815×10 6 Ω·cm -2 , The coating performance is good.

[0021] Example 2

[0022] Select 316L stainless steel, use laser engraving technology (laser repetition frequency is 30 kHz, engraving linear speed is 300 mm/s) to process the two-dimensional code pattern on the surface of the stainless steel, and then apply UV special metal ink to the pattern part of the two-dimensional code. After the ink is cured, the surface of the QR code label is treated with decontamination and degreasing, acid washing, water washing and drying before the varnish is applied. The decontamination is washed with absolute ethanol, and the degreasing liquid is 50g/L NaOH, 40g /L Na 2 CO 3 , Soak for 10min at room temperature; pickling solution is 50g/L HCl, 140g/L HNO 3 , Soak for 5 minutes at room temperature, rinse with distilled water, and quickly dry with a hair dryer. Finally, a layer of high weather resistance and corrosion resistance modified fluorocarbon varnish with a thickness of 80μm is applied to the entire label surface. The modification method is to add 1wt% sodium tripolyphosphate and 1wt% nano-TiO 2 , The QR code pattern is clear and effective. According to GB/T 16422.2-2014 "Plastic Laboratory Light Source Exposure Test Method Part 2: Xenon Arc Lamp" as the test standard, the prepared two-dimensional code label is subjected to the xenon lamp aging test with a test cycle of 3000h, which has a long life of the present invention After 3000h xenon lamp aging test, the color change level of the two-dimensional code label is 1, the two-dimensional code pattern is clear and effective, the impact strength retention rate is 78.5%, and the hardness decrease is 13.6%. After 1200h salt spray test, in addition to a small amount of edge corrosion due to edge effect, the QR code pattern is clear and effective. The impedance measured by electrochemical test is 2.831×10 6 Ω·cm -2 , The coating performance is good.

[0023] Example 3

[0024] Select 304 stainless steel, use laser engraving technology (laser repetition frequency is 25 kHz, engraving linear speed is 450 mm/s) to process the two-dimensional code pattern on the surface of the stainless steel, and then apply UV photosensitive ink and ink to the pattern part of the two-dimensional code After curing, the surface of the QR code label is treated with decontamination and degreasing, acid washing, water washing and drying before coating the varnish after curing. The decontamination is washed with absolute ethanol, and the degreasing liquid is 60g/L NaOH, 30g/ L Na 2 CO 3 , Soak for 8min at room temperature; pickling solution is 60g/L HCl, 150g/L HNO 3 , Soak for 8min at room temperature, rinse with distilled water and quickly dry with a hair dryer. Finally, a layer of modified silicone varnish with high weather resistance and corrosion resistance with a thickness of 75 μm is coated on the entire label surface, and the modification method is adding 2wt% ZnO and 1wt% epoxy resin microcapsules. The two-dimensional code label is subjected to electrochemical impedance test, the two-dimensional code label is used as the working electrode, the graphite electrode is the auxiliary electrode, and the saturated calomel electrode is used as the reference electrode. The medium is simulated seawater prepared in the laboratory, the medium temperature is 40℃, pH=6.0, and the chemical composition is: NaCl 24.53g/L, Na 2 SO 4 4.09g/L, MgCl 2 5.2g/L, CaCl 2 1.16g/L, SrCl 2 0.025g/L, KCl 0.695g/L, NaHCO 3 0.201g/L, KBr0.101g/L, NaF 0.003g/L, H 3 BO 3 0.027g/L. The test frequency range is 10 5 ~10 -2 Hz, sine wave AC excitation signal amplitude is 5mV. Use ZView2 software for analysis. Obtain the impedance change trend diagram of the QR code label as Figure 4 As shown, the long-life two-dimensional code label of the present invention has been immersed in sea water for 180 days, the two-dimensional code pattern is clear and effective, and its impedance is 2.293×10 6 Ω·cm -2 , Which shows that the two-dimensional code label has excellent corrosion resistance, and the varnish can play a long-term anti-corrosion effect on the two-dimensional code label.