Preparation method and curing method of deep curing and photochromic ink

Abstract

The present invention discloses a preparation method and a curing method of deep curing and photochromic ink. The preparation method specifically comprises the following steps: step 1, modifying nano calcium carbonate; step 2, preparing spiropyrile nano material according to the product obtained in step 1; step 3, modifying carbon black; step 4, preparing photochromic ink according to the products obtained in step 2 and step 3. The present invention also discloses a curing method of deep curing and photochromic ink, which enables the ink to be dual cured by light and hydroxyl induction, thereby improving the curing depth of the ink; at the same time, it can also rearrange and aggregate the photochromic molecules on the surface of the ink, so that the ink can achieve photochromic change.

Description

Technical Field

[0001] The invention belongs to the technical field of ink preparation, and relates to a preparation method and a curing method of deep-curing and photochromic ink. Background Art

[0002] Ink is an important printing material that can print or spray text, graphics, etc. on a carrier. Ink contains main ingredients and auxiliary ingredients mixed together to prepare a viscous liquid. With the increase in social demand, the types and output of inks have also expanded and grown accordingly. There are many ways to cure inks, including ultraviolet rays, ion beam radiation, infrared drying and other modes. Among them, ultraviolet curing has the advantages of low cost, high efficiency, and no damage to the substrate, and has been widely used. However, since various pigments often need to be added to the ink, ultraviolet radiation cannot penetrate during the curing process, which makes the internal photocuring of the ink slow or even stop; at the same time, during the curing process of the ink, from the perspective of the photochromic function, the ink color is usually darker, which has a greater impact on the photochromic performance of the ink. Affected by the color of the ink itself, the color of the photochromic function itself cannot be displayed. Summary of the invention

[0003] The purpose of the present invention is to provide a method for curing deep-layer and photochromic inks, which enables the ink to be dual-cured by light and hydroxyl induction, thereby increasing the curing depth of the ink; at the same time, it can also cause the photochromic molecules to rearrange and aggregate on the surface of the ink, thereby achieving photochromic changes in the ink.

[0004] Another object of the present invention is to provide a method for preparing deep-curing and photochromic inks.

[0005] The first technical solution adopted by the present invention is a method for preparing a deep curing and photochromic ink, which specifically comprises the following steps:

[0006] Step 1, modifying nano calcium carbonate;

[0007] Step 2, preparing spiropyrile nanomaterials according to the product obtained in step 1;

[0008] Step 3, modifying the carbon black;

[0009] Step 4, preparing photochromic ink according to the products obtained in steps 2 and 3.

[0010] The first technical solution of the present invention is also characterized in that:

[0011] The specific process of step 1 is:

[0012] Take 2-6g of nano calcium carbonate, disperse it in 30-90mL of a mixed solution of N,N-dimethylformamide and toluene, continue to add 2-6g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, then add 1mol / L sodium hydroxide solution until the pH is 10-11, increase the temperature to 100-160°C and react for 12-24 hours under nitrogen conditions. After the reaction is completed, add 60-120mL of anhydrous ethanol to the reaction solution, and centrifuge at 7000-10000r / min to obtain the modified nano calcium carbonate.

[0013] The specific process of step 2 is:

[0014] Take 5-15g of styryl spiropyran, 5-15g of perfluorobutyl acrylate, 0.2-0.6g of glyceryl propoxy acid triacrylate and 0.02-0.06g of initiator and add them into a flask, stir evenly at room temperature, heat to 60-120°C for half an hour, then add 1-3g of the nano-calcium carbonate modified in step 1, and continue to react for 2-6h to obtain spiropyran nanomaterial.

[0015] The specific process of step 3 is as follows:

[0016] Step 3.1, take 2-6 g of carbon black and disperse it in 10-30 mL of N,N-dimethylacetamide solution, add 0.3-0.9 g of NaH, activate at 60-120°C for 1-3 h, then add 4-vinylbenzyl chloride, continue to react at room temperature for 12-24 h, after the reaction is completed, filter to obtain a filter cake, wash the filter cake with 100 mL of ethanol, and repeat three times;

[0017] Step 3.2, weigh 1-3g of the filter cake obtained in step 3.1, add 5-15g of hydroxyethyl acrylate, 0.2-0.6g of glyceryl propoxypropoxy triacrylate and 0.02-0.06g of initiator into a flask, stir evenly at room temperature, heat to 60-120°C for half an hour, stop the reaction and quickly add 100-300 mL of industrial ethanol to terminate the reaction to obtain a black solid powder, dry at 45-90°C for 12-24h to obtain modified carbon black.

[0018] The initiator in step 2 and step 3.2 is azobisisobutyronitrile.

[0019] The specific process of step 4 is:

[0020] Take 0.5-1.5g of spiropyrile nanomaterial, 0.5-1.5g of modified carbon black, 1.5-4.5g of ethyl isocyanate acrylate, and 0.02-0.06g of azobisisobutyronitrile and add them to 5-15mL of ethyl acetate solution, ultrasonically disperse for 30-60 minutes, and continue stirring for 30-60 minutes to form a black gel liquid, i.e., ink.

[0021] The second technical solution adopted by the present invention is a method for deep curing and curing of photochromic ink. The specific process is as follows: take 2-6g of the prepared ink, print it on a 10 x 10cm white cardboard by screen printing, irradiate it with a 45-200W white light source for polymerization for 10-20 seconds, then place it in the air for 48-96 hours for deep curing, and then irradiate the ink under a 45W ultraviolet lamp for 10-20 seconds to complete the curing.

[0022] The beneficial effect of the present invention is that the present invention utilizes the dual curing ink mechanism induced by light and hydroxyl to achieve the purpose of deep curing of the ink. At the same time, photochromic pigment molecules with low surface energy are constructed. When the ink is cured, the pigment molecules are rearranged and aggregated on the surface of the ink. Finally, the ink is the intrinsic color of the ink before ultraviolet light irradiation, and the colorless pigment molecules change color after ultraviolet light irradiation. Since the pigment molecules are on the surface of the ink, the intrinsic color of the ink can be covered to show the color of the photochromic pigment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a comparison chart of ultraviolet absorption spectra of Example 1 and Comparative Examples 2 and 5 of the curing method of deep curing and photochromic ink of the present invention. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] The preparation method of the deep curing and photochromic ink of the present invention specifically comprises the following steps:

[0026] Step 1, modifying nano calcium carbonate, the specific process is as follows: take 2-6g of nano calcium carbonate, disperse it in 30-90mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 2-6g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 10-11. Raise the temperature to 100-160℃ and react for 12-24 hours under nitrogen. After the reaction is completed, add 60-120mL of anhydrous ethanol to the reaction solution, centrifuge at 7000-10000r / min to obtain the modified nano calcium carbonate.

[0027] Step 2, synthesizing spiropyrile nanomaterials, the specific process is as follows:

[0028] Take styryl spiropyran (5-15g), perfluorobutyl acrylate (5-15g), glyceryl propoxy acid triacrylate (0.2-0.6g) and initiator (azobisisobutyronitrile, 0.02-0.06g) and add them to a 50mL round-bottom flask, stir evenly at room temperature, heat to 60-120℃ and react for half an hour, then add the nano-calcium carbonate (1-3g) modified in step 1, continue to react for 2-6h, and obtain spiropyran nanomaterial for standby use.

[0029] Step 3, modifying the carbon black, specifically includes the following process:

[0030] Take 2-6g of carbon black, disperse it in 10-30 mL of N,N-dimethylacetamide solution, further add 0.3-0.9g of NaH, activate it at 60-120℃ for 1-3h, then add 1~2g of 4-vinylbenzyl chloride, continue to react at room temperature for 12-24h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (1-3g), add hydroxyethyl acrylate (5-15g), glyceryl propoxy acid triacrylate (0.2-0.6g) and initiator (azobisisobutyronitrile, 0.02-0.06g) to a 50mL round-bottom flask, stir evenly at room temperature, heat to 60-120℃ for half an hour, stop the reaction and quickly add 100-300mL of industrial ethanol to terminate the reaction, obtain black solid powder, dry it at 45-90℃ for 12-24h, obtain the modified carbon black, and set aside.

[0031] Step 4, preparation of photochromic ink, the specific process is as follows:

[0032] Take the spiropyrile nanomaterial (0.5-1.5g) prepared in step 2, the carbon black (0.5-1.5g) modified in step 3, ethyl isocyanate acrylate (1.5-4.5g), and azobisisobutyronitrile (0.02-0.06g) and add them to 5-15mL ethyl acetate solution, ultrasonically disperse for 30-60 minutes, and continue stirring for 30-60 minutes to form a black gel liquid, i.e., ink.

[0033] The curing method of deep curing and photochromic ink of the present invention comprises the following steps: 2-6 g of the ink prepared in step 4 is taken and printed on a 10 x 10 cm white card paper by screen printing. The ink is irradiated with a 45-200 W (300-1000 mW / cm2, wavelength range 380nm-780nm) white light source for polymerization for 10-20 s, and then placed in air for 48-96 hours for deep curing, and then the ink is irradiated with a 45 W (50 mW / cm2) ultraviolet lamp for 10-20 s to observe and detect photochromism.

[0034] Example 1

[0035] The preparation method of the deep curing and photochromic ink of the present invention specifically comprises the following steps:

[0036] Step 1, take 2g of nano calcium carbonate, disperse it in 30mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 2g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 10. Raise the temperature to 100℃ and react for 12 hours under nitrogen. After the reaction, add 60mL of anhydrous ethanol to the reaction solution, centrifuge at 7000r / min to obtain modified nano calcium carbonate.

[0037] Step 2, add styryl spiropyran (5 g), perfluorobutyl acrylate (5 g), glyceryl propoxy acid triacrylate (0.2 g) and initiator (azobisisobutyronitrile, 0.02 g) into a 50 mL round-bottom flask, stir evenly at room temperature, heat to 60 ° C for half an hour, then add the nano calcium carbonate (1 g) modified in step 1, continue to react for 2 hours, and obtain spiropyran nanomaterial for standby use.

[0038] Step 3, take 2g of carbon black, disperse it in 10mL of N,N-dimethylacetamide solution, further add 0.3g of NaH, activate it at 60℃ for 1h, then add 1g of 4-vinylbenzyl chloride, continue to react at room temperature for 12h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (1g), add hydroxyethyl acrylate (5g), glyceryl propoxy acid triacrylate (0.2g) and initiator (azobisisobutyronitrile, 0.02g) into a 50mL round-bottom flask, stir evenly at room temperature, heat to 60℃ for half an hour, stop the reaction and quickly add 100mL of industrial ethanol to terminate the reaction, obtain black solid powder, dry it at 45℃ for 12h, obtain the modified carbon black, and set aside.

[0039] Step 4: Take spiropyrile nanomaterial (0.5 g), functional modified carbon black (0.5 g), ethyl isocyanate acrylate (1.5 g), and azobisisobutyronitrile (0.02 g) and add them to 5 mL of ethyl acetate solution in sequence, ultrasonically disperse for 30 minutes, and continue stirring for 30 minutes to form a black gel liquid, i.e., ink.

[0040] The deep curing and photochromic ink curing method of the present invention comprises the following specific processes: taking 2 g of the ink prepared in step 4, printing it on a 10 x 10 cm white card paper by screen printing, irradiating it with a 45 W (300 mW / cm2, wavelength range 380 nm-780 nm) white light source for polymerization for 10 seconds, and then placing it in the air for 48 hours for deep curing, and then irradiating the ink with a 45 W (50 mW / cm2) ultraviolet lamp for 10 seconds to complete the curing, and observing and detecting the photochromism.

[0041] Comparative Example 1 (the ink was not added with modified nano-calcium carbonate, but directly added with spiropyran polymer, and the photochromic change could not be observed due to the light absorption of carbon black)

[0042] Step 1, add styryl spiropyran (5 g), perfluorobutyl acrylate (5 g), glyceryl propoxy acid triacrylate (0.2 g) and initiator (azobisisobutyronitrile, 0.02 g) into a 50 mL round-bottom flask, stir evenly at room temperature, heat to 60 ° C for half an hour to react, and synthesize spiropyran polymer for later use.

[0043] Step 2, take 2g of carbon black, disperse it in 10mL of N,N-dimethylacetamide solution, further add 0.3g of NaH, activate it at 60℃ for 1h, then add 1g of 4-vinylbenzyl chloride, continue to react at room temperature for 12h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (1g), add hydroxyethyl acrylate (5g), glyceryl propoxy acid triacrylate (0.2g) and initiator (azobisisobutyronitrile, 0.02g) into a 50mL round-bottom flask, stir evenly at room temperature, heat to 60℃ for half an hour, stop the reaction and quickly add 100mL of industrial ethanol to terminate the reaction, obtain black solid powder, dry it at 45℃ for 12h, obtain the modified carbon black, and set aside.

[0044] Step 3, take spiropyran polymer (0.5g), carbon black modified in step 2 (0.5g), ethyl isocyanate acrylate (1.5g), and azobisisobutyronitrile (0.02g) and add them to 5mL ethyl acetate solution in sequence, ultrasonically disperse for 30 minutes, and continue stirring for 30 minutes to form a black gel liquid to obtain ink.

[0045] The ink prepared in step 3 was cured, and 2 g of the prepared ink was screen printed on a 10 x 10 cm white cardboard. After irradiation with a 45 W (300 mW / cm2) white light source for 10 s, the ink was placed in the air for 48 hours for deep curing, and then the ink was irradiated with a 45 W (50 mW / cm2) UV lamp for 10 s to complete curing, and the photochromism was observed and detected.

[0046] Comparative Example 2 (Replacing carbon black with nano titanium dioxide, the ink cannot be cured when exposed to white light)

[0047] Step 1, take 2g of nano calcium carbonate, disperse it in 30mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 2g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 10. Raise the temperature to 100℃ and react for 12 hours under nitrogen. After the reaction, add 60mL of anhydrous ethanol to the reaction solution, centrifuge at 7000r / min to obtain modified nano calcium carbonate.

[0048] Step 2, add styryl spiropyran (5 g), perfluorobutyl acrylate (5 g), glyceryl propoxy acid triacrylate (0.2 g) and initiator (azobisisobutyronitrile, 0.02 g) into a 50 mL round-bottom flask, stir evenly at room temperature, heat to 60 ° C for half an hour, then add the nano calcium carbonate (1 g) modified in step 1, continue to react for 2 hours, and obtain spiropyran nanomaterial for standby use.

[0049] Step 3, take 2g of nano titanium dioxide, disperse it in 10mL of N,N-dimethylacetamide solution, further add 0.3g of NaH, activate it at 60℃ for 1h, then add 1g of 4-vinylbenzyl chloride, continue to react at room temperature for 12h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (1g), add hydroxyethyl acrylate (5g), glyceryl propoxy acid triacrylate (0.2g) and initiator (azobisisobutyronitrile, 0.02g) to a 50mL round-bottom flask, stir evenly at room temperature, heat to 60℃ for half an hour, stop the reaction and quickly add 100mL of industrial ethanol to terminate the reaction, obtain a white solid powder, dry it at 45℃ for 12h, and obtain the modified nano titanium dioxide for standby use.

[0050] Step 4: Take spiropyrile nanomaterial (0.5 g), nano titanium dioxide (0.5 g) modified in step 3, ethyl isocyanate acrylate (1.5 g), and azobisisobutyronitrile (0.02 g) and add them to 5 mL of ethyl acetate solution in sequence, ultrasonically disperse for 30 minutes, and continue stirring for 30 minutes to form a white gel liquid, i.e., ink.

[0051] 2g of the ink prepared in step 4 was printed on a 10 x 10cm white cardboard by screen printing. After being irradiated with a 45W (300mW / cm2) white light source for 10 seconds, the ink was placed in air for 48 hours for deep curing. The ink was then irradiated with a 45W (50 mW / cm2) UV lamp for 10 seconds to complete curing, and the photochromism was observed and tested.

[0052] Comparative Example 3 (When synthesizing spiropyrile nanomaterials, perfluorobutyl acrylate was replaced with butyl acrylate, and photochromism could not be observed)

[0053] Step 1, take 2g of nano calcium carbonate, disperse it in 30mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 2g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 10. Raise the temperature to 100℃ and react for 12 hours under nitrogen. After the reaction, add 60mL of anhydrous ethanol to the reaction solution, centrifuge at 7000r / min to obtain modified nano calcium carbonate.

[0054] Step 2, add styryl spiropyran (5 g), butyl acrylate (5 g), glyceryl propoxy triacrylate (0.2 g) and initiator (azobisisobutyronitrile, 0.02 g) into a 50 mL round-bottom flask, stir evenly at room temperature, heat to 60 ° C for half an hour, then add functional nano calcium carbonate (1 g), continue to react for 2 hours, and obtain spiropyran nanomaterial for standby use.

[0055] Step 3, take 2g of carbon black, disperse it in 10mL of N,N-dimethylacetamide solution, further add 0.3g of NaH, activate it at 60℃ for 1h, then add 1g of 4-vinylbenzyl chloride, continue to react at room temperature for 12h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (1g), add hydroxyethyl acrylate (5g), glyceryl propoxy acid triacrylate (0.2g) and initiator (azobisisobutyronitrile, 0.02g) into a 50mL round-bottom flask, stir evenly at room temperature, heat to 60℃ for half an hour, stop the reaction and quickly add 100mL of industrial ethanol to terminate the reaction, obtain black solid powder, and obtain the modified carbon black for standby use.

[0056] Step 4: Take spiropyrile nanomaterial (0.5 g), carbon black modified in step 3 (0.5 g), ethyl isocyanate acrylate (1.5 g), and azobisisobutyronitrile (0.02 g) and add them to 5 mL of ethyl acetate solution in sequence, ultrasonically disperse for 30 minutes, and continue stirring for 30 minutes to form a black gel liquid, i.e., ink.

[0057] Take 2g of the ink prepared in step 4 and print it on a 10 x 10cm white cardboard by screen printing. After irradiation with a 45W (300mW / cm2) white light source for 10 seconds, the ink is placed in air for 48 hours for deep curing. After that, the ink is irradiated with a 45W (50 mW / cm2) UV lamp for 10 seconds to complete the curing, and the photochromism is observed and tested.

[0058] Comparative Example 4 (When carbon black functional modification was performed, hydroxyethyl acrylate was replaced with perfluorobutyl acrylate, and the photochromic phenomenon could not be observed, and the inner layer of the ink was poorly cured)

[0059] Step 1, take 2g of nano calcium carbonate, disperse it in 30mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 2g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 10. Raise the temperature to 100℃ and react for 12 hours under nitrogen. After the reaction, add 60mL of anhydrous ethanol to the reaction solution, centrifuge at 7000r / min to obtain modified nano calcium carbonate.

[0060] Step 2, add styryl spiropyran (5 g), perfluorobutyl acrylate (5 g), glyceryl propoxy acid triacrylate (0.2 g) and initiator (azobisisobutyronitrile, 0.02 g) into a 50 mL round-bottom flask, stir evenly at room temperature, heat to 60 ° C for half an hour, then add the nano calcium carbonate (1 g) modified in step 1, continue to react for 2 hours, and obtain spiropyran nanomaterial for standby use.

[0061] Step 3, take 2g of carbon black, disperse it in 10mL of N,N-dimethylacetamide solution, further add 0.3g of NaH, activate it at 60℃ for 1h, then add 1g of 4-vinylbenzyl chloride, continue to react at room temperature for 12h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (1g), add perfluorobutyl acrylate (5g), glyceryl propoxy acid triacrylate (0.2g) and initiator (azobisisobutyronitrile, 0.02g) into a 50mL round-bottom flask, stir evenly at room temperature, heat to 60℃ for half an hour, stop the reaction and quickly add 100mL of industrial ethanol to terminate the reaction, obtain black solid powder, dry at 45℃ for 12h, obtain modified carbon black, and set aside.

[0062] Step 4: Take spiropyrile nanomaterial (0.5 g), carbon black modified in step 3 (0.5 g), ethyl isocyanate acrylate (1.5 g), and azobisisobutyronitrile (0.02 g) and add them to 5 mL of ethyl acetate solution in sequence, ultrasonically disperse for 30 minutes, and continue stirring for 30 minutes to form a black gel liquid, i.e., ink.

[0063] Take 2 g of the ink prepared in step 4 and print it on a 10 x 10 cm white cardboard by screen printing. After irradiation with a 45 W (300 mW / cm2) white light source for 10 s, the ink is placed in the air for 48 hours for deep curing. The ink is then irradiated with a 45 W (50 mW / cm2) ultraviolet lamp for 10 s to complete curing, and the photochromism is observed and detected.

[0064] Comparative Example 5 (In the preparation of photochromic ink, ethyl isocyanate acrylate was replaced with ethyl acrylate, and deep curing was insufficient)

[0065] Step 1, take 2g of nano calcium carbonate, disperse it in 30mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 2g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 10. Raise the temperature to 100℃ and react for 12 hours under nitrogen. After the reaction, add 60mL of anhydrous ethanol to the reaction solution, centrifuge at 7000r / min to obtain the product, and obtain the modified nano calcium carbonate.

[0066] Step 2, add styryl spiropyran (5 g), perfluorobutyl acrylate (5 g), glyceryl propoxy acid triacrylate (0.2 g) and initiator (azobisisobutyronitrile, 0.02 g) into a 50 mL round-bottom flask, stir evenly at room temperature, heat to 60 ° C for half an hour, then add the nano calcium carbonate (1 g) modified in step 1, continue to react for 2 hours, and obtain spiropyran nanomaterial for standby use.

[0067] Step 3, take 2g of carbon black, disperse it in 10mL of N,N-dimethylacetamide solution, further add 0.3g of NaH, activate it at 60℃ for 1h, then add 1g of 4-vinylbenzyl chloride, continue to react at room temperature for 12h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (1g), add hydroxyethyl acrylate (5g), glyceryl propoxy acid triacrylate (0.2g) and initiator (azobisisobutyronitrile, 0.02g) into a 50mL round-bottom flask, stir evenly at room temperature, heat to 60℃ for half an hour, stop the reaction and quickly add 100mL of industrial ethanol to terminate the reaction, obtain black solid powder, dry it at 45℃ for 12h, obtain the modified carbon black, and set aside.

[0068] Step 4: Take spiropyrrolidone nanomaterial (0.5 g), carbon black modified in step 3 (0.5 g), ethyl acrylate (1.5 g), and azobisisobutyronitrile (0.02 g) and add them to 5 mL of ethyl acetate solution in sequence, ultrasonically disperse for 30 minutes, and continue stirring for 30 minutes to form a black gel liquid, i.e., ink.

[0069] Take 2g of the ink prepared in step 4 and print it on a 10 x 10cm white cardboard by screen printing. After irradiation with a 45W (300mW / cm2) white light source for 10 seconds, place it in the air for 48 hours for deep curing, and then irradiate the ink with a 45W (50 mW / cm2) UV lamp for 10 seconds to complete the curing, and observe and detect the photochromism.

[0070] The ink properties prepared in Example 1 and Comparative Examples 1 to 5 were tested, and the results are shown in Table 1 below:

[0071] Table 1

[0072] sample Ink surface light curing Ink deep hydroxyl curing Color before photoresponse Color after light response Example 1 yes yes black pink Comparative Example 1 yes yes black black Comparative Example 2 no yes White pink Comparative Example 3 yes yes black black Comparative Example 4 yes no black black Comparative Example 5 yes no black pink

[0073] Results Analysis

[0074] In Comparative Example 1, modified nano-calcium carbonate is not added to the ink, but spiropyran polymer is directly added. Although the spiropyran polymer can be rearranged on the surface when solidified, the carbon black is black and the black background light is absorbed, so the photochromism cannot be observed.

[0075] In Comparative Example 2, carbon black was replaced with nano titanium dioxide, and the ink could not be cured when exposed to white light. This is because nano titanium dioxide is white, and its light absorption efficiency is much lower than that of carbon black, so it cannot convert visible light into heat to achieve surface curing of the ink. Affected by the white background of titanium dioxide, photochromism is obvious, and the ink changes from colorless to pink. It should be pointed out that although it is difficult to cure the surface of carbon black replaced with titanium dioxide, it contains isocyanate functional groups, which can react with air in the opposite direction to form moisture curing. The disadvantage is that the curing time is as long as 72 hours.

[0076] In the synthesis of the spiropyrile nanomaterial in Comparative Example 3, perfluorobutyl acrylate was replaced with butyl acrylate, and photochromism could not be observed. Since perfluorobutyl acrylate contains a large amount of fluorine, the fluorine has good hydrophobicity and can form a repulsive force with the hydroxyl (hydrophilicity) in the functional modified carbon black, inducing the spiropyrile nanomaterial to rearrange on the surface, and photochromism can be achieved. After replacing butyl acrylate in Comparative Example 3, the hydrophobicity is poor and the surface rearrangement of the spiropyrile nanomaterial cannot be induced.

[0077] In comparative example 4, when the carbon black function is modified, hydroxyethyl acrylate is replaced by perfluorobutyl acrylate, resulting in the carbon black being repeated on the surface, covering the photochromic properties of the spiropyrrolidone nanomaterial. At the same time, due to the replacement with perfluorobutyl acrylate, the hydroxyl functional group of hydroxyethyl acrylate is missing, resulting in the inability of isocyanate to react with the hydroxyl group for curing.

[0078] In the preparation of the photochromic ink in Comparative Example 5, ethyl isocyanate acrylate was replaced with ethyl acrylate, which lacked isocyanate functional groups and could not react with hydroxyl groups for curing, but the photochromic phenomenon could be observed.

[0079] like Figure 1 As shown, Example 1 and Comparative Examples 2 and 5 have obvious absorption peaks at 520 nm, so people can observe their complementary color pink. On the contrary, since Comparative Examples 1, 3, and 4 are black, no absorption spectrum can be detected.

[0080] Example 2

[0081] The preparation method of the deep curing and photochromic ink of the present invention specifically comprises the following steps:

[0082] Step 1, take 4g of nano calcium carbonate, disperse it in 60mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 4g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 10. Raise the temperature to 120℃ and react for 18 hours under nitrogen. After the reaction, add 100mL of anhydrous ethanol to the reaction solution, centrifuge at 9000r / min to obtain modified nano calcium carbonate.

[0083] Step 2, take styryl spiropyran (10g), perfluorobutyl acrylate (10g), glyceryl propoxy acid triacrylate (0.4g) and initiator (azobisisobutyronitrile, 0.04g) and add them to a 50mL round-bottom flask, stir evenly at room temperature, heat to 100°C for half an hour, then add the nano-calcium carbonate (2g) modified in step 1, continue to react for 4h, and obtain spiropyran nanomaterial for standby use.

[0084] Step 3, take 4g of carbon black, disperse it in 20mL of N,N-dimethylacetamide solution, further add 0.6g of NaH, activate at 100℃ for 1h, then add 1.5g of 4-vinylbenzyl chloride, continue to react at room temperature for 18h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (2g), add hydroxyethyl acrylate (10g), glyceryl propoxy acid triacrylate (0.4g) and initiator (azobisisobutyronitrile, 0.04g) into a 50mL round-bottom flask, stir evenly at room temperature, heat to 100℃ for half an hour, stop the reaction and quickly add 200mL of industrial ethanol to terminate the reaction, obtain black solid powder, dry at 75℃ for 18h, obtain modified carbon black, and set aside.

[0085] Step 4: Take spiropyrile nanomaterial (0.8 g), carbon black modified in step 3 (0.8 g), ethyl isocyanate acrylate (3.6 g), and azobisisobutyronitrile (0.04 g) and add them to 10 mL of ethyl acetate solution in sequence, ultrasonically disperse for 40 minutes, and continue stirring for 40 minutes to form a black gel liquid, i.e., ink.

[0086] The deep curing and photochromic ink curing method of the present invention comprises the following specific processes: taking 4 g of the ink prepared in step 4, printing it on a 10 x 10 cm white card paper by screen printing, irradiating it with a 100 W (800 mW / cm2, wavelength range 380 nm-780 nm) white light source for polymerization for 15 seconds, and then placing it in the air for 68 hours for deep curing, and then irradiating the ink with a 45 W (50 mW / cm2) ultraviolet lamp for 15 seconds to complete the curing, and observing and detecting the photochromism.

[0087] Example 3

[0088] The preparation method of the deep curing and photochromic ink of the present invention specifically comprises the following steps:

[0089] Step 1, take 6g of nano calcium carbonate, disperse it in 90mL of N,N-dimethylformamide and toluene (volume ratio 1:1) mixed solution, continue to add 6g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, and then add 1 mol / L sodium hydroxide solution until the pH is 11. Raise the temperature to 160℃ and react for 24 hours under nitrogen. After the reaction, add 120mL of anhydrous ethanol to the reaction solution, centrifuge at 10000r / min to obtain the modified nano calcium carbonate.

[0090] Step 2, add styryl spiropyran (15 g), perfluorobutyl acrylate (15 g), glyceryl propoxy acid triacrylate (0.6 g) and initiator (azobisisobutyronitrile, 0.06 g) into a 50 mL round-bottom flask, stir evenly at room temperature, heat to 120 ° C for half an hour, then add the nano calcium carbonate (3 g) modified in step 1, continue to react for 6 hours, and obtain spiropyran nanomaterial for standby use.

[0091] Step 3, take 6g of carbon black, disperse it in 30mL of N,N-dimethylacetamide solution, further add 0.9g of NaH, activate it at 120℃ for 3h, then add 2g of 4-vinylbenzyl chloride, continue to react at room temperature for 24h, after the reaction is completed, filter to obtain the filter cake, wash the filter cake with 100mL of ethanol, repeat three times. Weigh the obtained filter cake (3g), add hydroxyethyl acrylate (15g), glyceryl propoxy acid triacrylate (0.6g) and initiator (azobisisobutyronitrile, 0.06g) into a 50mL round-bottom flask, stir evenly at room temperature, heat to 120℃ for half an hour, stop the reaction and quickly add 300mL of industrial ethanol to terminate the reaction, obtain black solid powder, dry at 90℃ for 24h, obtain modified carbon black, and set aside.

[0092] Step 4: Take spiropyrile nanomaterial (1.5 g), carbon black modified in step 3 (1.5 g), ethyl isocyanate acrylate (4.5 g), and azobisisobutyronitrile (0.06 g) and add them to 15 mL of ethyl acetate solution in sequence, ultrasonically disperse for 60 minutes, and continue stirring for 60 minutes to form a black gel liquid, i.e., ink.

[0093] The deep curing and photochromic ink curing method of the present invention comprises the following specific processes: 6 g of the ink prepared in step 4 is taken, printed on a 10 x 10 cm white card paper by screen printing, irradiated with a 200 W (1000 mW / cm2, wavelength range 380 nm-780 nm) white light source for polymerization for 20 seconds, then placed in air for 96 hours for deep curing, and then the ink is irradiated with a 45 W (50 mW / cm2) ultraviolet lamp for 20 seconds to complete curing, and the photochromic change is observed and detected.

[0094] In the present invention, the ink is subjected to dual curing by light irradiation and hydroxyl induction, which solves the problem that light curing is easily absorbed by the dye and cannot penetrate, and improves the curing depth of the ink. The light used is visible light, which achieves deep curing. When the ink is cured, the surface of the photochromic pigment molecules is rearranged, and the intrinsic color of the ink can be displayed before the color change stimulation. After the color change stimulation, the pigment molecules change from colorless to colored, and the pigment color is not affected by the intrinsic color of the ink. If the photochromic pigment does not rearrange after curing, but is evenly dispersed in the ink, the photochromic change is affected by the intrinsic color, especially the black ink, and the photochromic material is completely ineffective.

Claims

1. A method for preparing a deep curing and photochromic ink, characterized in that: The specific steps include: Step 1, modifying nano calcium carbonate; Step 2, preparing spiropyrile nanomaterials according to the product obtained in step 1; Step 3, modifying the carbon black; Step 4, preparing a photochromic ink according to the products obtained in steps 2 and 3, The specific process of step 1 is as follows: Take 2-6g of nano calcium carbonate and disperse it in 30-90mL of N,N-dimethylformamide and toluene mixed solution, continue to add 2-6g of 3-(methacryloyloxy)propyltrimethoxysilane, stir evenly at room temperature, then add 1 mol / L sodium hydroxide solution until the pH is 10-11, raise the temperature to 100-160 o C and react under nitrogen for 12-24 hours. After the reaction is completed, 60-120 mL of anhydrous ethanol is added to the reaction solution, and the modified nano calcium carbonate is obtained by centrifugation at a speed of 7000-10000 r / min. The specific process of step 2 is: Take 5-15g of styryl spiropyran, 5-15g of perfluorobutyl acrylate, 0.2-0.6g of glyceryl propoxyhexanoic acid triacrylate and 0.02-0.06g of initiator into a flask, stir evenly at room temperature, and heat to 60-120 o C for half an hour, then add 1-3g of the nano calcium carbonate modified in step 1, and continue to react for 2-6h to obtain the spiropyrile nanomaterial. The specific process of step 3 is as follows: Step 3.1, take 2-6g of carbon black and disperse it in 10-30mL of N,N-dimethylacetamide solution, add 0.3-0.9g of NaH, 60-120 o C activation for 1-3h, then add 4-vinylbenzyl chloride and continue to react at room temperature for 12-24h. After the reaction is completed, filter to obtain a filter cake, wash the filter cake with 100mL of ethanol, and repeat three times; Step 3.2, weigh 1-3g of the filter cake obtained in step 3.1, add 5-15g of hydroxyethyl acrylate, 0.2-0.6g of glyceryl propoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxypropoxy o C for half an hour, then add 100-300 mL of industrial ethanol to terminate the reaction, and obtain a black solid powder, 45-90 o C and dried for 12-24h to obtain modified carbon black.

2. The method for preparing a deep curing and photochromic ink according to claim 1, characterized in that: The initiators in step 2 and step 3.2 are both azobisisobutyronitrile.

3. The method for preparing a deep curing and photochromic ink according to claim 1, characterized in that: The specific process of step 4 is as follows: Take 0.5-1.5g of spiropyrile nanomaterial, 0.5-1.5g of modified carbon black, 1.5-4.5g of ethyl isocyanate acrylate, and 0.02-0.06g of azobisisobutyronitrile and add them to 5-15mL of ethyl acetate solution, ultrasonically disperse for 30-60 minutes, and continue stirring for 30-60 minutes to form a black gel liquid, i.e., ink.

4. A method for curing deep layer and photochromic ink, characterized in that: The specific process is as follows: take 2-6g of the ink prepared by the preparation method according to any one of claims 1-3, print it on a 10 x 10cm white cardboard by screen printing, irradiate with a 45-200W white light source for polymerization for 10-20 seconds, then place it in the air for 48-96 hours for deep curing, and then irradiate the ink under a 45W ultraviolet lamp for 10-20 seconds to complete the curing.

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