CN112210364B - Photochromic material, preparation method and application thereof - Google Patents

Abstract

The invention relates to the technical field of photochromic materials, in particular to a photochromic material and a preparation method and application thereof. The photochromic material comprises a compound A and a compound B. The compound A is taken as a guest compound, the compound B is taken as a main compound, and the compound A is doped into the compound B, so that the photochromic anti-counterfeiting ink has an obvious photochromic effect and can be used in the fields of anti-counterfeiting printing, writing ink and the like.

Description

Photochromic material, preparation method and application thereof

technical field

The invention relates to the technical field of photochromic materials, in particular to a photochromic material and a preparation method and application thereof.

Background technique

With the development of society, counterfeit and shoddy products have brought great economic, environmental and even health problems to human society. Under certain ultraviolet excitation light stimulation, the color of the color-changing material can change rapidly and obviously, such as from white to yellow or red, and can quickly return to the original color under the irradiation of LED white light. Therefore, it is widely used in the fields of biological imaging, devices, encryption and anti-counterfeiting.

However, traditional photochromic materials will face the disadvantages of weak contrast of material color change, long illumination time required for color change, and certain fatigue after several restorations. Most importantly, due to the complex synthesis of materials, the cost is so high that it is difficult to achieve large-scale industrial production. Therefore, it is necessary to develop simple, effective and economical photochromic materials.

In view of this, the present invention is proposed.

SUMMARY OF THE INVENTION

The first object of the present invention is to provide a photochromic material to solve the technical problems in the prior art, such as weak contrast of the color change of the photochromic material.

The second object of the present invention is to provide a method for preparing a photochromic material, which has a simple synthesis process and mild conditions.

The third object of the present invention is to provide the application of the photochromic material, such as in the fields of anti-counterfeiting printing and writing ink.

In order to realize the above-mentioned purpose of the present invention, the following technical solutions are specially adopted:

Photochromic materials, including compound A and compound B;

The structural formula of the compound A is as follows:

R ₁ is selected from H, halogen, substituted or unsubstituted aryl-containing structures; the aryl-containing structures include

中的任一种；

any of the

R ₂ is selected from the substituted or unsubstituted aryl-containing structures;

The structural formula of the compound B is as follows:

R ₃ and R ₄ are each independently selected from any one of H, F, Cl, Br, I, -OH, -OCH ₃ and -CH ₃ .

In the photochromic material of the present invention, compound A is used as a guest compound, compound B is used as a host compound, and compound A is doped into compound B, which has an obvious photochromic effect.

Under the action of ultraviolet light, the appearance color of the photochromic material of the present invention will rapidly change from white to deep red, and can maintain a deep red state for more than 12 hours under dark conditions, and can maintain a deep red state for 5-10 minutes under conventional indoor light. Moreover, after the photochromic material turns deep red, the photochromic material changes from deep red to white after being irradiated with LED, white light, or mobile phone light source for about 10 seconds; and the material can still be kept in this way for more than 10 times. Excellent color changing properties.

In addition, the compound A of the present invention is simple to synthesize, the compound B has wide sources and low cost, and is suitable for industrial production.

In addition, the doping material is very insensitive to humidity, oxygen, etc., and still has a very good photochromic effect in a humid environment.

* as referred to in the present invention denotes the position of attachment of the group to the rest of the compound.

In a specific embodiment of the present invention, in the substituted aryl group-containing structure, the substituent may be any one of an alkyl group, an alkoxy group, a halogen group, and an ester group. For example, it can be C _1-3 alkyl, including methyl, ethyl, n-propyl, isopropyl and the like.

In a specific embodiment of the present invention, the structural formula of the compound A is selected from any of the following:

In a specific embodiment of the present invention, the halogen includes any one of F, Cl, Br and I, preferably Br.

中的任一种。In a specific embodiment of the present invention, the aryl-containing structure is selected from

any of the.

In a specific embodiment of the present invention, the compound B is benzophenone or 4-methylbenzophenone.

In a specific embodiment of the present invention, the preparation method of the compound A comprises any one of route a) and route b):

wherein R is R ₁ or R ₂ .

The specific methods of route a) include:

At room temperature, 2,6-dimethylpyrone is brominated with a brominating agent such as N-bromosuccinimide (NBS) to obtain compound I;

Compound I and compound C are subjected to Suzuki coupling reaction to obtain compound A _x .

Wherein, the conditions of the Suzuki coupling reaction include: compound I and compound C are reacted under the action of tetrakistriphenylphosphonium palladium and potassium carbonate, and the mixture of tetrahydrofuran and water is used as a solvent at 75～85 ℃ under nitrogen atmosphere for 10 ~15h.

Specific methods for route b) include:

At room temperature, 2,6-dimethylpyrone is brominated with a brominating agent such as N-bromosuccinimide (NBS) to obtain compound II;

Compound II is subjected to Suzuki coupling reaction with compound C to obtain compound A _y1 or A _y2 .

Wherein, the conditions for the Suzuki coupling reaction include: compound II and compound C are reacted under the action of tetrakistriphenylphosphonium palladium and potassium carbonate, and a mixture of tetrahydrofuran and water is used as a solvent at 75-85 ° C under nitrogen atmosphere for 10 ~15h.

Wherein, the volume ratio of tetrahydrofuran and water used as a solvent is (5-15):1, such as 10:1.

In practice, in the bromination reaction of 2,6-dimethylpyrone NBS, compound I with mono-substituted bromine group and compound II with di-substituted bromine group will be obtained at the same time. Compound I and compound II were obtained by separation methods such as analysis.

In a specific embodiment of the present invention, the molar ratio of compound I to compound C is 1:(1-1.5), for example, it can be 1:1.2.

In a specific embodiment of the present invention, the molar ratio of compound II to compound C is 1:(1-1.5), for example, it can be 1:1.2.

In a specific embodiment of the present invention, the addition amount of the tetrakistriphenylphosphonium palladium is 2% to 10% of the mass of the compound I, preferably 5%; the addition amount of the potassium carbonate is the compound 5% to 15% of the mass of I, preferably 10%.

In a specific embodiment of the present invention, the addition amount of the tetrakistriphenylphosphonium palladium is 2% to 10% of the mass of the compound II, preferably 5%; the addition amount of the potassium carbonate is the compound 5% to 15% of the mass of II, preferably 10%.

In a specific embodiment of the present invention, the dosage ratio of the compound I to the solvent is 1 mmol: (2-3) mL, such as 1 mmol: 2.2 mL.

In a specific embodiment of the present invention, the amount ratio of the compound II to the solvent is 1 mmol: (2-3) mL, such as 1 mmol: 2.2 mL.

In actual operation, after the Suzuki coupling reaction is completed, the corresponding compounds A _x , A _y1 , and A _y2 are obtained by separation and purification by conventional column chromatography.

In a specific embodiment of the present invention, the molar ratio of the compound A and the compound B is 1:(50-20000). More preferably, the molar ratio of the compound A and the compound B is 1:(100-2000), more preferably 1:(200-1000), still more preferably 1:1000.

As in different embodiments, the molar ratio of the compound A and the compound B may be 1:50, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1 :700, 1:800, 1:900, 1:1000, 1:1200, 1:1400, 1:1600, 1:1800, 1:2000, 1:3000, 1:4000, 1:5000, 1:10000 , 1:15000, 1:20000, etc.

The present invention also provides a method for preparing the above-mentioned photochromic material, comprising the following steps:

The compound B is uniformly mixed with the compound A in a molten state.

The compound B used in the present invention has good meltability, and can dissolve the compound A in the molten state, so that the compound A is uniformly dispersed in the compound B.

In a specific embodiment of the present invention, the compound B is melted to a molten state under heating conditions of 50-60°C.

In a specific embodiment of the present invention, it also includes: after the mixing is uniform, cooling to room temperature naturally. Naturally cooled to room temperature to slowly crystallize the molten compound B containing the guest molecule-compound A to obtain a solid photochromic material. The preparation method of the invention has simple operation and is suitable for large-scale production.

The present invention also provides the application of any one of the above-mentioned photochromic materials in preparing ink and/or ink.

Further, the inks and/or inks are anti-counterfeiting printing inks and/or inks, or writing and painting inks and/or inks.

In actual operation, the photochromic material prepared above can be heated to a molten state, and directly used as ink to perform calligraphy and painting on the surface of the substrate. Wherein, the base material includes any one of printing paper and filter paper. The writing and drawing obtained by this method are white under a white light, but when irradiated with ultraviolet light, the white words or patterns quickly turn into deep red, which has high anti-counterfeiting and encryption.

In a specific embodiment of the present invention, after the printing or writing and painting, the color is developed under the irradiation of 300-450 nm ultraviolet light, and the color is restored under the irradiation of 500-600 nm or white light.

Compared with the prior art, the beneficial effects of the present invention are:

(1) Under the action of ultraviolet light, the appearance color of the photochromic material of the present invention will rapidly change from white to deep red, and can maintain a deep red state for more than 12 hours under dark conditions, and can maintain a deep red state for 5～5～2 hours under conventional indoor light. 10min. Moreover, after the photochromic material turns deep red, the photochromic material changes from deep red to white after being irradiated with LED, white light, or mobile phone light source for about 10 seconds; and the material can still be kept in this way for more than 10 times. Excellent color changing properties.

(2) The photochromic material of the present invention has a wide range of raw materials, is simple to synthesize, and is suitable for large-scale production.

(3) The photochromic material of the present invention can be used for anti-counterfeiting printing and writing ink, and has high anti-counterfeiting and encryption properties.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

1 is a schematic diagram of the appearance color change of the photochromic material provided in Example 1 of the present invention before and after different illumination;

Fig. 2 is the ultraviolet absorption repeatability of the photochromic material provided in Example 1 of the present invention in the treatment of alternating irradiation of ultraviolet light and LED white light;

3 is a schematic diagram of the appearance and color change of the photochromic material provided in Example 1 of the present invention before and after different illuminations at different temperatures or in water;

Fig. 4 is the ultraviolet absorption spectrogram of the photochromic material provided in Example 1 of the present invention before and after different illumination;

Fig. 5 is the color change of the pattern written using the photochromic material provided by Example 1 of the present invention before and after different illumination;

6 is a schematic diagram of the appearance color change of the photochromic material provided in Example 2 of the present invention before and after different illumination;

Fig. 7 is the ultraviolet absorption spectrogram of the photochromic material provided in Example 2 of the present invention before and after different illumination;

Fig. 8 is the color change of the pattern written by adopting the photochromic material provided by Example 2 of the present invention before and after different illumination;

9 is a schematic diagram of the appearance color change before and after different illumination of the photochromic material provided by Example 3 of the present invention;

Fig. 10 is the ultraviolet absorption spectrogram of the photochromic material provided in Example 4 of the present invention before and after different illumination;

Figure 11 shows the color changes of the patterns written by using the photochromic material and compound B1 provided in Example 1 of the present invention respectively before and after different illumination; "CHEMIS" is written in molten compound B1, and "TRY" is written in molten Example 1 writing on photochromic materials;

Fig. 12 is the hydrogen nuclear magnetic spectrum of compound A ₂ of the present invention;

Fig. 13 is the hydrogen nuclear magnetic spectrum of compound A ₅ of the present invention;

Fig. 14 is a hydrogen NMR spectrum of Compound A ₈ of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments, It is only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used without the manufacturer's indication are conventional products that can be purchased from the market.

In a specific embodiment of the present invention, the structural formula of compound B of compound A used is as follows:

Compound A:

Compound B:

The synthetic route of compound A that each embodiment of the present invention adopts is as follows:

Include either of route a) and route b):

wherein R is R ₁ or R ₂ .

The specific methods of route a) include:

At room temperature, 2,6-dimethylpyrone is brominated with a brominating agent such as N-bromosuccinimide (NBS) to obtain compound I;

Compound I and compound C are subjected to Suzuki coupling reaction to obtain compound A _x .

Wherein, the conditions for the Suzuki coupling reaction include: compound I and compound C are reacted under the action of tetrakistriphenylphosphonium palladium and potassium carbonate, and a mixture of tetrahydrofuran and water is used as a solvent at 75-85° C. under nitrogen atmosphere for 10 ~15h.

Specific methods for route b) include:

At room temperature, 2,6-dimethylpyrone is brominated with a brominating agent such as N-bromosuccinimide (NBS) to obtain compound II;

Compound II is subjected to Suzuki coupling reaction with compound C to obtain compound A _y1 or A _y2 .

Wherein, the conditions for the Suzuki coupling reaction include: compound II and compound C are reacted under the action of tetrakistriphenylphosphonium palladium and potassium carbonate, and a mixture of tetrahydrofuran and water is used as a solvent at 75-85° C. under nitrogen atmosphere for 10 ~15h.

Wherein, the volume ratio of tetrahydrofuran and water used as a solvent is (5-15):1, such as 10:1.

In practice, in the bromination reaction of 2,6-dimethylpyrone NBS, compound I with mono-substituted bromine group and compound II with di-substituted bromine group will be obtained at the same time. Compound I and compound II were obtained by separation methods such as analysis.

Taking compound A1 as an example, its synthetic route and method are described in detail as follows:

At room temperature, 2,6-dimethylpyranone is brominated with N-bromosuccinimide (NBS) to obtain compound I;

Then take 10 mmol of compound I and 12 mmol of compound C ₁ , 5% of compound I by mass of tetrakistriphenylphosphonium palladium, 10% of compound I by mass of potassium carbonate, 20 mL of tetrahydrofuran and 2 mL of water, mix them, and put them in a nitrogen protective atmosphere. The reaction was carried out at 75-85°C for 12h. After the reaction, the target compound A ₁ was obtained by separation and purification by column chromatography.

Compound A ₂ is reacted according to the first method of route b), and the molar ratio of compound II and compound C ₁ is 1:2.4 for Suzuki reaction.

Compound A ₃ is reacted according to the second method of route b), and the molar ratio of compound II and compound C ₁ is 1:1.2 for Suzuki reaction.

Compound A ₄ is reacted according to route a), and the molar ratio of compound I and compound C ₂ is 1:1.2 for Suzuki reaction; the structural formula of compound C ₂ is:

Compound A ₅ is reacted according to the first method of route b), and the molar ratio of compound II and compound C ₂ is 1:2.4 for Suzuki reaction.

Compound A ₆ is reacted according to the second route of route b), and the molar ratio of compound II and compound C ₂ is 1:1.2 to undergo Suzuki reaction.

Compound A ₇ is reacted according to route a), and the molar ratio of compound I and compound C ₃ is 1:1.2 for Suzuki reaction; the structural formula of compound C ₃ is:

Compound A ₈ is reacted according to the first method of route b), and the molar ratio of compound II and compound C ₃ is 1:2.4 for Suzuki reaction.

Compound A ₉ is reacted according to the second route of route b), and the molar ratio of compound II and compound C ₃ is 1:1.2 to undergo Suzuki reaction.

Compound A ₁₀ is reacted according to route a), and the molar ratio of compound I and compound C ₄ is 1:1.2 for Suzuki reaction; the structural formula of compound C ₄ is

Compound A ₁₁ is reacted according to the first method of route b), and the molar ratio of compound II and compound C ₄ is 1:2.4 for Suzuki reaction.

Compound A ₁₂ is reacted according to the second route of route b), and the molar ratio of compound II and compound C ₄ is 1:1.2 for Suzuki reaction.

Compound A ₁₃ is reacted according to route a), and the molar ratio of compound I and compound C ₅ is 1:1.2 for Suzuki reaction; the structural formula of compound C ₅ is

Compound A ₁₄ is reacted according to the first method of route b), and the molar ratio of compound II and compound C ₅ is 1:2.4 for Suzuki reaction.

Compound A ₁₅ is reacted according to the second route of route b), and the molar ratio of compound II and compound C ₅ is 1:1.2 for Suzuki reaction.

The structure of each compound was characterized by hydrogen NMR and mass spectrometry, and it was confirmed that the compound with the corresponding structure was prepared. Taking compounds A ₂ , A ₅ and A ₈ as examples for illustration, their hydrogen NMR spectra are shown in Figures 12 to 14, respectively.

Example 1

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₂ and 10 mmol of compound B ₁ benzophenone, and heat them to 50°C in a container to melt the benzophenone and dissolve compound A _2. After the two are evenly mixed, naturally cool to room temperature , to obtain a photochromic material.

Example 2

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₅ and 10 mmol of compound B ₁ benzophenone, and heat it to 50°C in a container to melt the benzophenone and dissolve compound A _5. After the two are evenly mixed, naturally cool to room temperature , to obtain a photochromic material.

Example 3

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₈ and 10 mmol of compound B ₁ benzophenone, and heat them to 50°C in a container to melt the benzophenone and dissolve compound A _5. After the two are evenly mixed, naturally cool to room temperature , to obtain a photochromic material.

Example 4

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₂ and 10 mmol of compound B ₂ 4-methyl benzophenone, heat it to 60°C in a container, melt 4-methyl benzophenone and dissolve compound A ₂ , both After mixing uniformly, naturally cooled to room temperature to obtain a photochromic material.

Example 5

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₁ and 10 mmol of compound B ₁ benzophenone, and heat them to 50°C in a container to melt the benzophenone and dissolve compound A _1. After the two are evenly mixed, naturally cool to room temperature , to obtain a photochromic material.

Example 6

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₃ and 10 mmol of compound B ₁ benzophenone, and heat them to 50°C in a container to melt the benzophenone and dissolve compound A _3. After the two are evenly mixed, naturally cool to room temperature , to obtain a photochromic material.

Example 7

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₄ and 10 mmol of compound B ₁ benzophenone, and heat them to 50°C in a container to melt the benzophenone and dissolve compound A _4. After the two are evenly mixed, naturally cool to room temperature , to obtain a photochromic material.

Example 8

The present embodiment provides a method for preparing a photochromic material, comprising the following steps:

Weigh 0.01 mmol of compound A ₆ and 10 mmol of compound B ₁ benzophenone, and heat them to 50°C in a container to melt the benzophenone and dissolve compound A _6. After the two are evenly mixed, naturally cool to room temperature , to obtain a photochromic material.

Experimental example 1

In order to illustrate the discoloration performance of the photochromic material of the present invention, the appearance color changes of the photochromic material of Example 1 before and after different illumination were detected, as shown in FIG. 1 , which is the photochromic material provided in Example 1 of the present invention. Schematic diagram of the appearance color change of the color-changing material before and after different illumination. Fig. 1(a) is a photo of melting benzophenone and dissolving compound A ₂ (not down to room temperature) in Example 1, which is a transparent liquid; after 30min, it is naturally cooled to room temperature, and the appearance is shown in Fig. 1(b) ), a white solid was formed; after 30s of ultraviolet light at 360 nm, it turned into a red solid, and its appearance was shown in Figure 1(c); after 10s of LED white light irradiation, it returned to the initial white solid state, and its appearance was shown in Figure 1(c). 1(d).

In order to further verify the repeatability of the discoloration performance of the photochromic material of the present invention, the photochromic material prepared in Example 1 was taken to test its initial ultraviolet absorption, and then after 30s of ultraviolet light at 360 nm, its ultraviolet absorption was tested. , and then after irradiating the LED white light for 10s, test its ultraviolet absorption, repeating alternately several times. Figure 2 shows the UV absorption repeatability of the photochromic material provided in Example 1 under the treatment of alternate irradiation of UV light and LED white light. It can be seen from FIG. 2 that the photochromic material of the present invention has good repeatability.

Experimental example 2

In order to illustrate the insensitivity of the photochromic material of the present invention to humidity, etc., the photochromic material of Example 1 was tested in water for its appearance and color changes before and after different illumination, as shown in FIG. 3 , which is the implementation of the present invention. A schematic diagram of the appearance and color change of the photochromic material provided in Example 1 before and after different illumination in water.

Taking 25°C as an example to illustrate, the photochromic material was irradiated with 360nm ultraviolet light for 30s at 25°C, the solid color changed from white to red, and then placed under natural light indoors for 5min, the solid color remained red, and then in After 10s irradiation with LED white light, the solid color returns from red to white. This is due to the weak intensity of indoor natural light, which allows the material to remain in the red state for a certain period of time.

The photochromic material was soaked in water at 25°C for five minutes, and filtered to obtain a sample with a large humidity. After irradiating with 360nm ultraviolet light for 30s, the color of the powder in water changed from white to red, and then placed under natural light for 5min, the solid color remained red, and then after 10s irradiation with LED white light, the solid color returned from red to white.

As can be seen from the above, the photochromic material of the present invention is insensitive to humidity.

Experimental example 3

FIG. 4 is an ultraviolet absorption spectrum diagram of the photochromic material provided in Example 1 of the present invention before and after different illumination. It can be seen from the figure that before UV irradiation compared with after UV irradiation, after UV irradiation, a new absorption peak is generated at about 530 nm, but after LED white light irradiation, the new absorption peak at 530 nm disappears.

Figure 5 shows the color change of the pattern written by using the photochromic material provided in Example 1 of the present invention before and after different illumination. Figure 5(a) is a pattern of writing and drawing directly as ink on the surface of the substrate after the photochromic material of Example 1 is heated to melt, and the appearance is white; after 360nm ultraviolet light irradiation, the appearance is red, as shown in the figure As shown in 5(b); and then after irradiating with LED white light, the appearance returns to white.

Experimental example 4

Detect the appearance color change of the photochromic material of Example 2 before and after different illumination, as shown in FIG. 6 , which is a schematic diagram of the appearance color change of the photochromic material provided in Example 2 of the present invention before and after different illumination. In Figure 6(a) is the appearance of the initial photochromic material in Example 2; after 30s irradiation with 360nm ultraviolet light, the appearance is red, as shown in Figure 6(b); placed under dark conditions for 24h, photochromic The material remains red, and its appearance is shown in Figure 6(c); then after 10 s of LED white light irradiation, it returns to the initial white solid state, and its appearance is shown in Figure 6(d).

FIG. 7 is an ultraviolet absorption spectrum diagram of the photochromic material provided in Example 2 of the present invention before and after different illumination. It can be seen from the figure that before UV light irradiation, compared with after UV light irradiation, after UV light irradiation, a new absorption peak is generated at about 525 nm, while after LED white light irradiation, the new absorption peak at 525 nm disappears.

Figure 8 shows the color change of the pattern written by using the photochromic material provided in Example 2 of the present invention before and after different illumination. Figure 8 (a) is a pattern of writing and painting directly as ink on the surface of the substrate after the photochromic material of Example 2 is heated to melt, and the appearance is close to white; after 365nm ultraviolet light irradiation, the appearance is red, such as As shown in Fig. 8(b); and then irradiated with LED white light, the appearance is restored to close to white.

Experimental example 5

Detect the appearance color change of the photochromic material of Example 3 before and after different illumination, as shown in FIG. 9 , which is a schematic diagram of the appearance color change of the photochromic material provided in Example 3 of the present invention before and after different illumination. In Figure 9 (a) is the appearance of the initial photochromic material in Example 3; after 360nm ultraviolet light irradiation for 2min, the appearance is red, as shown in Figure 9 (b); placed under dark conditions for 12h, photochromic The material remains red, and its appearance is shown in Figure 9(c); then after 10 s of LED white light irradiation, it returns to the initial white solid state, and its appearance is shown in Figure 9(d).

FIG. 10 is an ultraviolet absorption spectrum diagram of the photochromic material provided in Example 4 of the present invention before and after different illumination. It can be seen from the figure that before UV light irradiation, compared with after UV light irradiation, after UV light irradiation, a new absorption peak is generated at about 525 nm, while after LED white light irradiation, the new absorption peak at 525 nm disappears.

Similarly, the photochromic materials provided in Examples 5-8 also have similar effects.

Experimental example 6

The photochromic material of Example ₁ of the present invention and compound B1 were used to write patterns, and the patterns were subjected to certain lighting conditions to check the color changes of the patterns written by the photochromic material of Example 1 and compound B1 before and after lighting. See Fig. 11 for details. In Fig. 11, "CHEMIS" is written with compound B1 in molten state, and "TRY" is written with the photochromic material of Example 1 in molten state. "CHEMIS" did not change the appearance color after 360nm UV light irradiation, while "TRY" changed the pattern to red after 360nm UV light irradiation. After the pattern is irradiated with ultraviolet light, the color of the "CHEMIS" pattern remains unchanged after being irradiated by the LED white light lamp, while the color of the "TRY" pattern returns from red to the original color.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (15)

1. A photochromic material, characterized in that it comprises compound A and compound B; The structural formula of the compound A is as follows:

R ₁ is selected from H, halogen, substituted or unsubstituted aryl-containing structures; the aryl-containing structures include

any of the R ₂ is selected from the substituted or unsubstituted aryl-containing structures; The structural formula of the compound B is as follows:

R ₃ and R ₄ are each independently selected from any one of H, F, Cl, Br, I, -OH, -OCH ₃ and -CH ₃ . 2. The photochromic material according to claim 1, wherein the structural formula of the compound A is selected from any of the following:

3. The photochromic material according to claim 1, wherein the aryl-containing structure is selected from

any of the. 4 . The photochromic material according to claim 1 , wherein the compound B is benzophenone or 4-methylbenzophenone. 5 . 5 . The photochromic material according to claim 1 , wherein the molar ratio of the compound A and the compound B is 1:(50˜20000). 6 . 6 . The photochromic material according to claim 1 , wherein the molar ratio of the compound A and the compound B is 1:(100-2000). 7 . 7 . The photochromic material according to claim 1 , wherein the molar ratio of the compound A and the compound B is 1:(200˜1000). 8 . 8. the preparation method of the photochromic material described in any one of claim 1-7, is characterized in that, comprises the steps: The compound B is uniformly mixed with the compound A in a molten state. 9 . The method for preparing a photochromic material according to claim 8 , wherein the compound B is melted to a molten state under a heating condition of 50-60° C. 10 . 10 . The method for preparing a photochromic material according to claim 9 , further comprising: after the mixing is uniform, cooling to room temperature naturally. 11 . 11. Use of the photochromic material of any one of claims 1-7 in the preparation of ink and/or ink. 12. The application according to claim 11, wherein the ink is anti-counterfeiting printing ink or writing and painting ink; and the ink is anti-counterfeiting printing ink or writing and painting ink. 13 . The application according to claim 12 , wherein the photochromic material is heated to a molten state, and printing or writing and painting is performed on the surface of the substrate. 14 . 14. The application according to claim 13, wherein the substrate comprises printing paper or filter paper. 15 . The application according to claim 13 , wherein after the printing or writing and painting, the color is developed under the irradiation of 300-450 nm ultraviolet light, and the color is restored under the irradiation of 500-600 nm or white light. 16 .

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