Preparation of bromine-containing seven-membered fluorine boron compound and application of bromine-containing seven-membered fluorine boron compound in fluorescent ink

Abstract

The invention discloses preparation of a bromine-containing seven-membered fluorine boron compound and application of the bromine-containing seven-membered fluorine boron compound in fluorescent ink, 2, 3, 3-trimethylindole and 5-formyl-2, 4-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester are used as raw materials, under the action of acetic acid, piperidine and methylbenzene, a Knoevenagel condensation reaction is carried out, and a seven-membered fluorine boron fluorescent dye is generated. The seven-membered fluorine-boron fluorescent dye and NBS (N-bromosuccinimide) are subjected to free radical reaction to generate an innovative structure. The compound has high fluorescence quantum yield in some solutions, can be dissolved in an n-butyl alcohol solution of acrylic resin, can be used as fluorescent ink to act on materials such as parchment paper and glass plates, has high concealment, and is simple and easy to obtain.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and more specifically, to the preparation of a novel bromine-containing heptafluoroborate compound. Such compounds have a high fluorescence quantum yield and can be widely applied in the field of fluorescent inks. Background Art

[0002] Fluorescent inks contain fluorescent agents that produce a fluorescence effect when exposed to ultraviolet light (365 nm) (such as ultraviolet light emitted by sunlight, fluorescent lamps, mercury lamps, etc.). The key principle is to add visible fluorescent (complex) compounds that are excited by ultraviolet light to the ink. After these compounds absorb light energy, atomic energy level transitions occur, and then the absorbed extra energy is released, thereby emitting visible light of colors such as red, yellow, green, and blue. Such inks are usually used to enhance the security of documents or products, for example, on currency, passports, tickets, and other items that require anti-counterfeiting measures. Fluorescent inks come in various colors, commonly including yellow-green, orange-red, blue-green, etc. These colors are almost invisible under normal light but will show bright fluorescence under ultraviolet light.

[0003] Fluorescent inks have high brightness, can produce a strong visual impact; have high color saturation, are vivid and do not fade; can increase the visual hierarchy and three-dimensional sense of printed matter, making patterns or text more vivid and eye-catching; some fluorescent inks also have high transparency and are suitable for overprinting to form a unique visual effect.

[0004] The applications of fluorescent inks are not limited to commercial advertisements but are also widely used in decorative printing and safety signs, which helps to improve the visibility and recognition of signs. In addition, due to their concealability and convertibility, fluorescent inks also have important applications in anti-counterfeiting printing. Through ultraviolet irradiation, special fluorescent patterns or text can be displayed to achieve anti-counterfeiting detection. When using fluorescent inks, special attention needs to be paid to their compatibility with the printing medium or coating layer to ensure the best fluorescence effect and service life. Summary of the Invention

[0005] The present invention provides a preparation method of a bromine-containing heptafluoroborate compound and its application research in fluorescent inks. This compound is not only simple and easily obtainable, has a low manufacturing cost, a high fluorescence quantum yield, but also has little environmental pollution.

[0006] A bromine-containing heptafluoroborate compound and its application in fluorescent inks, the chemical structural formula of the compound is:

[0007] A synthesis method for synthesizing the bromine-containing heptafluoroborate compound, the method includes the following synthesis route:

[0008] The method specifically includes the following steps: (1) At room temperature, add Compound 1, that is, 2,3,3-trimethylindole, and Compound 2, that is, ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate, to the reaction flask. After dissolving in toluene, successively add piperidine and acetic acid, and then heat to 120 °C to react to obtain a reaction solution; (2) Rotavaporize the reaction solution in step (1) to remove toluene, and then obtain the solid product 3 through silica gel column chromatography separation; (3) Successively add Compound 3 obtained in step (2), NBS, and AlCl 3 , and finally add chloroform and dissolve it by ultrasonic treatment to obtain a reaction solution; (4) Rotavaporize the solvent chloroform from the reaction solution in step (3), and obtain the solid product I, that is, a bromine-containing heptafluoroborate compound, through silica gel column chromatography separation.

[0009] Compound 3 is a heptafluoroborate compound, and Compound I is a bromine-containing heptafluoroborate compound; the feeding ratio of Compound 3 to NBS is 1:1 to 2, and the feeding ratio of Compound 3 to AlCl 3 is 1:0.5 to 2.

[0010] The feeding order in step (1) is Compound 1, Compound 2, toluene, acetic acid, and piperidine as a catalyst should be added last.

[0011] The feeding order in step (3) is Compound 3, NBS, AlCl 3 , and dissolve it with chloroform.

[0012] The heating temperature in step (1) is 120 °C, and the heating time is 2.5 hours. The reaction temperature in step (3) is 0 to 40 °C, and the heating time is 10 minutes to 1 hour.

[0013] Another technical solution of the present invention is the application of the bromine-containing heptafluoroborate compound as a fluorescent ink.

[0014] Specifically, disperse acrylic resin in a n-butanol solution, then add the bromine-containing heptafluoroborate compound to obtain a fluorescent ink. Coat the fluorescent ink on a substrate, and it has a fluorescent effect under ultraviolet light.

[0015] The addition amount of the bromine-containing heptafluoroborate compound is 1.0% to 1.5%.

[0016] The ultraviolet light is an ultraviolet light source of 365 nm - 380 nm; the substrate includes any one of paper, steel plate, wood, A4 paper, and glass material.

[0017] The beneficial effects of the present invention are as follows: (1)The bromine-containing heptafluoroborate compound synthesized by the present invention has a high fluorescence quantum yield, is simple to obtain, has a low manufacturing cost, and low pollution.

[0018] (2)The bromine-containing heptafluoroborate compound of the present invention has great potential in the field of fluorescent inks, and has a significant fluorescence effect when the mass ratio of the fluorescent powder is 1.0% - 1.5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the 1H NMR spectrum of Compound 3 obtained in Example 1.

[0020] Figure 2 is the 1H NMR spectrum of Compound I obtained in Example 3.

[0021] Figure 3 is the clear fluorescence image obtained by photographing with a Huawei nova 12 mobile phone under natural light and under an ultraviolet lamp (365 nm) after the fluorescent ink prepared from Compound I of Example 10-1 acts on sulfuric acid paper.

[0022] Figure 4 is the clear fluorescence image obtained by photographing with a Huawei nova 12 mobile phone under natural light and under an ultraviolet lamp (365 nm) after the fluorescent ink prepared from Compound I of Example 10-2 acts on sulfuric acid paper.

[0023] Figure 5 is the clear fluorescence image obtained by photographing with a Huawei nova 12 mobile phone under natural light and under an ultraviolet lamp (365 nm) after the fluorescent ink prepared from Compound I of Example 10-3 acts on sulfuric acid paper.

[0024] Figure 6 is the clear fluorescence image obtained by photographing with a Huawei nova 12 mobile phone under natural light and under an ultraviolet lamp (365 nm) after the fluorescent ink prepared from Compound I of Example 10-4 acts on sulfuric acid paper.

[0025] Figure 7 is the clear fluorescence image obtained by photographing with a Huawei nova 12 mobile phone under natural light and under an ultraviolet lamp (365 nm) after the fluorescent ink prepared from Compound 3 of Example 10-5 acts on sulfuric acid paper.

[0026] Figure 8 is the comparison of the clear fluorescence image of the fluorescent ink prepared from Compound I of Example 10-2 acting on sulfuric acid paper and the clear fluorescence image of the fluorescent ink prepared in the patent "Preparation of a Phosphorus-Containing Heptafluoroborate Compound and Its Application in Fluorescent Ink". DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described below in conjunction with embodiments, but the scope of protection required by the present invention is not limited to the scope described in the embodiments.

[0028] Example 1 Weigh 2,3,3 - trimethylindole (573 mg, 3.6 mmol) and ethyl 5 - formyl - 2,4 - dimethyl - 1H - pyrrole - 3 - carboxylate (585 mg, 3 mmol). After dissolving them in 15 mL of toluene, successively add piperidine (297 μL, 3 mmol) and acetic acid (171 μL, 3 mmol). React at 120 °C for 2.5 hours. After cooling to room temperature, remove toluene by rotary evaporation. Finally, obtain the yellow solid compound 3 through silica gel column chromatography, with a yield of 63.7%.

[0029] 。

[0030] Example 2 Weigh the heptafluoroborate fluorescent dye of compound 3 (463.9 mg, 1 mmol). After dissolving it in 5.00 mL of chloroform, successively add NBS (178 mg, 1 mmol) and AlCl 3 (66.5 mg, 0.5 mmol). Stir and react at room temperature for 1 hour until the reaction is complete. After extracting the reactants and rotary evaporating, obtain the red solid compound I through column chromatography, with a yield of 56.5%.

[0031] 。

[0032] Example 3 Weigh the heptafluoroborate fluorescent dye of compound 3 (463.9 mg, 1 mmol). After dissolving it in 5.00 mL of chloroform, successively add NBS (178 mg, 1 mmol) and AlCl 3 (133 mg, 1 mmol). Then add 10 mL of chloroform and dissolve it by ultrasonic treatment. Stir and react at room temperature for 40 minutes until the reaction is complete. After extracting the reactants and rotary evaporating, obtain the product through column chromatography. Compared with Example 2, the catalyst is increased by 0.5 equivalent, the reaction time is shortened by 30 minutes, and the yield is increased by 11.7%.

[0033] 。

[0034] Example 4 Weigh the heptafluoroborate fluorescent dye of compound 3 (463.9 mg, 1 mmol). After dissolving it in 5.00 mL of chloroform, successively add NBS (178 mg, 1 mmol) and AlCl 3(266 mg, 2 mmol). After adding 10 mL of chloroform and dissolving it by ultrasound, the mixture was stirred at room temperature for 0.5 hour, and the reaction was complete. The reactants were extracted and then rotary evaporated, and the product was obtained after column chromatography. Compared with Example 3, when the equivalent of AlCl 3 was doubled, the reaction time was shortened by ten minutes, and the yields were not much different, but obvious carbonization occurred.

[0035] .

[0036] Example 5 Weigh 463.9 mg (1 mmol) of the heptafluoroborate fluorescent dye of Compound 3. After dissolving it in 5.00 mL of chloroform, NBS (178 mg, 1 mmol) and AlCl 3 (133 mg, 1 mmol) were successively added. After adding 10 mL of chloroform and dissolving it by ultrasound, the mixture was stirred at 0 °C for 1 hour, and the reaction was incomplete. The reactants were extracted and then rotary evaporated, and Compound I was obtained after column chromatography. Compared with Example 3, the reaction temperature was 0 °C, under ice bath conditions, which affected the reaction rate, so the yield decreased by 21.8%.

[0037] .

[0038] Example 6 Weigh 463.9 mg (1 mmol) of the heptafluoroborate fluorescent dye of Compound 3. After dissolving it in 5.00 mL of chloroform, NBS (178 mg, 1 mmol) and AlCl 3 (133 mg, 1 mmol) were successively added. After adding 10 mL of chloroform and dissolving it by ultrasound, the mixture was stirred at 40 °C for 0.5 hour, and the reaction was complete. The reactants were extracted and then rotary evaporated, and the red solid Compound I was obtained after column chromatography. Compared with Example 3, the temperature was increased by 15 °C, and carbonization occurred after heating, and the yield decreased by 11.4%.

[0039] .

[0040] Example 7 Weigh 463.9 mg (1 mmol) of the heptafluoroborate fluorescent dye of Compound 3. After dissolving it in 5.00 mL of chloroform, NBS (356 mg, 2 mmol) and AlCl 3 (133 mg, 1 mmol) were successively added. After adding 10 mL of chloroform and dissolving it by ultrasound, the mixture was stirred at room temperature for 10 minutes, and the reaction was complete. The reactants were extracted and then rotary evaporated, and the red solid was obtained after column chromatography. Compared with Example 3, when the equivalent ratio of NBS was doubled, the by-products increased, the reaction time was shortened by 20 minutes, and the yield decreased by 36%.

[0041] .

[0042] Example 8 Weigh 3-heptafluoroboron fluorophore dye (463.9 mg, 1 mmol). After dissolving it in 5.00 mL of chloroform, successively add NBS (356 mg, 1 mmol) and AlCl 3 (133 mg, 1 mmol). Then add 20 mL of chloroform and dissolve it by ultrasonic treatment. Stir the reaction at room temperature for 50 minutes until the reaction is complete. After extraction and rotary evaporation of the reactants, a red solid is obtained by column chromatography. Compared with Example 3, the solvent volume is increased by 5 mL, the reaction time is extended by 20 minutes, and the yield is reduced by 8.1%.

[0043] 。

[0044] Example 9 Weigh 3-heptafluoroboron fluorophore dye (463.9 mg, 1 mmol). After dissolving it in 5.00 mL of chloroform, successively add NBS (356 mg, 1 mmol) and AlCl 3 (133 mg, 1 mmol). Then add 5 mL of chloroform and dissolve it by ultrasonic treatment. Stir the reaction at room temperature for 1 hour. After extraction and rotary evaporation of the reactants, a red solid is obtained by column chromatography. Compared with Example 3, the solvent volume is reduced by 5 mL, the dissolution is insufficient, the reaction is incomplete, the reaction time is extended by 40 minutes, and the yield is reduced by 39.3%.

[0045] 。

[0046] Example 10 Preparation of Fluorescent Ink Example 10-1 Disperse acrylic resin (30 mg) evenly in n-butanol (290 mg). Stir until completely dissolved under magnetic stirring, and let it stand for 10 minutes to form a uniformly dispersed carrier. Then add Compound I (2 mg). After pre-dispersing for 30 minutes on a magnetic electric stirrer, stir at high speed to obtain the required color paste. Apply the obtained color paste to sulfuric acid paper and take pictures with a Huawei nova 12 under natural light and ultraviolet light (365 nm) respectively to obtain Figure 3 , and it can be seen that there is no fluorescent effect under natural light (left), and under ultraviolet light at 365 nm (right), the fluorescent effect can be clearly seen.

[0047] Example 10-2 Disperse acrylic resin (30 mg) evenly in n-butanol (290 mg), stir under magnetic stirring until completely dissolved, let it stand for 10 minutes to form a uniformly dispersed carrier, then add Compound I (4 mg), pre-disperse it on a magnetic electric stirrer for 30 minutes, and then stir at high speed to obtain the required color paste. Apply the obtained color paste to sulfuric acid paper and take pictures with a Huawei nova 12 under natural light and ultraviolet light (365 nm) respectively to obtain Figure 4 , it can be seen that there is no fluorescence effect under natural light (left), and under ultraviolet light at 365 nm (right), the fluorescence effect can be clearly seen.

[0048] Example 10-3 Disperse acrylic resin (30 mg) evenly in n-butanol (290 mg), stir under magnetic stirring until completely dissolved, let it stand for 10 minutes to form a uniformly dispersed carrier, then add Compound I (8 mg), pre-disperse it on a magnetic stirrer for 30 minutes, and then stir at high speed to obtain the required color paste. Apply the obtained color paste to sulfuric acid paper and take pictures with a Huawei nova 12 under natural light and ultraviolet light (365 nm) respectively to obtain Figure 5 , it can be seen that there is no fluorescence effect under natural light (left), and under ultraviolet light at 365 nm (right), the fluorescence effect can be clearly seen.

[0049] Example 10-4 Disperse acrylic resin (30 mg) evenly in n-butanol (290 mg), stir under magnetic stirring until completely dissolved, let it stand for 10 minutes to form a uniformly dispersed carrier, then add Compound I (16 mg), pre-disperse it on a magnetic stirrer for 30 minutes, and then stir at high speed to obtain the required color paste. Apply the obtained color paste to sulfuric acid paper and take pictures with a Huawei nova 12 under natural light and ultraviolet light (365 nm) respectively to obtain Figure 6 , it can be seen that there is no fluorescence effect under natural light (left), and under ultraviolet light at 365 nm (right), the fluorescence effect can be clearly seen.

[0050] Through the comparison of Examples 10-1, 10-2, 10-3, and 10-4, it is found that the best effect is obtained when the mass ratio of the phosphor is 1.0% - 1.5%. When the mass of the phosphor is small, such as in Example 10-1, the fluorescence in the right figure is weak. Doubling the mass of the phosphor successively, it can be seen that the fluorescence shown in the right figure of Example 10-2 is the strongest. However, when the mass of the phosphor is doubled or even quadrupled further, due to the fluorescence inhibition effect, Figure 5 and Figure 6 the fluorescence in the right figure weakens instead and is not as obvious as that in Example 10-2.

[0051] Example 10-5 Disperse acrylic resin (30 mg) evenly in n-butanol (290 mg), stir until completely dissolved under magnetic stirring, let stand for 10 minutes to form a uniformly dispersed carrier, then add Compound 3 (4 mg), pre-disperse for 30 minutes on a magnetic stirrer, and then stir at high speed to obtain the required color paste. Applying the obtained color paste to sulfuric acid paper, it can be seen that there is no fluorescence effect under natural light, and under ultraviolet light of 365 nm, the fluorescence effect can be clearly seen as Figure 7 .

[0052] Example 10-6 Compared with Compounds I-1, I-2, and I-3 mentioned in the patent "Preparation of a Phosphorus-Containing Heptatomic Boron Fluoride Compound and Its Application in Fluorescent Ink", the fluorescence effect is stronger, specifically as Figure 8 .

[0053] Both of the two compounds described in this patent can obtain fluorescent ink through the above-mentioned example methods. The fluorescent ink prepared in this patent can also be applied to materials such as steel plates, wood, A4 paper, and glass.

[0054] The above-mentioned examples are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The examples in this application and the features in the examples can be combined arbitrarily without conflict. The protection scope of the present invention should be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A bromine-containing seven-membered fluorine-boron compound, characterized in that: The structural formula of the compound is shown below: Ⅰ。 2. The method for synthesizing the bromine-containing seven-membered fluorine boron compound according to claim 1, characterized in that: This is achieved by: The method comprises the following steps: (1) Add compound 1, i.e. 2,3,3-trimethylindole, and compound 2, i.e. 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester, to a reaction bottle at room temperature. After toluene is dissolved, piperidine and acetic acid are added in sequence, and the temperature is raised to react to obtain a reaction solution; (2) removing toluene from the reaction solution in step (1) by rotary evaporation, and then separating by silica gel column chromatography to obtain a solid product 3; (3) adding the solid product 3 obtained in step (2), NBS, and AlCl3 to the reaction bottle in sequence, and finally adding chloroform to dissolve by ultrasonication, and reacting to obtain a reaction solution; (4) The reaction solution in step (3) is subjected to rotary evaporation to remove the solvent chloroform, and then separated by silica gel column chromatography to obtain a solid product I, i.e., a bromine-containing seven-membered fluoroborane compound.

3. The method for synthesizing the bromine-containing seven-membered fluorine boron compound according to claim 2, characterized in that: In the step (1), the molar ratio of compound 1 to compound 2 is 1:1-2.

4. The method for synthesizing the bromine-containing seven-membered fluorine boron compound according to claim 2, characterized in that: The heating temperature of step (1) is 110-120° C. and the heating time is 2-4 hours.

5. The method for synthesizing the bromine-containing seven-membered fluorine boron compound according to claim 2, characterized in that: In step (3), the molar ratio of the solid product 3, NBS and AlCl3 is 1:1~2:0.5~2.

6. The method for synthesizing the bromine-containing seven-membered fluorine boron compound according to claim 2, characterized in that: The reaction temperature of step (3) is 0-40°C, and the reaction time is 10 minutes-1 hour.

7. Use of the bromine-containing seven-membered fluorine boron compound according to claim 1 as fluorescent ink.

8. The use according to claim 7, characterized in that: After dispersing acrylic resin in n-butanol solution, adding the bromine-containing seven-membered fluoroboric compound of claim 1 to obtain fluorescent ink, coating the fluorescent ink on a substrate, and having a fluorescent effect under ultraviolet light.

9. The use according to claim 8, characterized in that: The addition amount of the bromine-containing seven-membered fluoroboric compound is 1.0%~1.5%.

10. The use according to claim 9, characterized in that: The ultraviolet light is an ultraviolet light source of 365nm-380nm; the substrate includes any one of paper, steel plate, wood, A4 paper and glass material.

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