Photochromic material as well as preparation method and application thereof

Abstract

The invention provides a photochromic material as well as a preparation method and application thereof. The photochromic material has a molecular structure as shown in a formula I. In the formula I, R1 is a C1-C20 alkyl group, R2 is a propylidene group or an ethylidene aminopropyl group, R3 is a C1-C5 alkyl group, R4 is a C1-C20 alkyl group or aryl group, and a is 0 or 1. By chemically improving the molecular structure of the photochromic material, the compatibility of the photochromic material in an organic matrix can be improved, and meanwhile, through the combined action of specific groups (such as an active amino unit, a polar N, S-acetal unit and an aromatic ring skeleton), the rapid photochromic reaction and the adhesion with a base material can be further ensured; the color change stability is further improved, and the service life of a photochromic product is prolonged. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more particularly to a photochromic material, a preparation method thereof, and an application thereof. Background Art

[0002] Organosilicon, that is, organic compounds containing silicon-carbon bonds, has unique chemical properties and a wide range of application fields. Organosilicon can be used as surfactants, coatings and waterproof materials, elastomers, adhesives, agricultural auxiliaries, medical, electronics, cosmetics and daily necessities, etc. Different applications require different structures and properties, and there are certain requirements for the anti-counterfeiting and product tracking of materials. Photochromic materials refer to a class of materials that can change color after being excited by a light source, and their color changes are generally reversible. Photochromic materials have a wide range of applications in many fields, such as information storage, decoration and protection, anti-counterfeiting labels and electronic components, energy conservation and environmental protection, etc.

[0003] Photochromic materials can be divided into organic photochromic materials and inorganic photochromic materials. Among them, the compatibility of organic photochromic materials with organosilicon is not particularly high. Under conditions such as light, heat, and water, they will slowly migrate, resulting in the migration of organic photochromic molecules to the surface and gradually losing and finally losing the anti-counterfeiting identification function. In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of the present invention is to improve the compatibility of the existing photochromic materials in the organic matrix, which leads to the non-persistent color-changing anti-counterfeiting performance of the products. By improving the molecular structure of the photochromic materials, their compatibility in the organic matrix can be improved, while ensuring a rapid photochromic reaction and adhesion to the substrate.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a photochromic material, and the photochromic material has a molecular structure as shown in Formula I:

[0007]

[0008] Formula I, R 1 is an alkyl group with 1 to 20 carbon atoms, R 2 is propylene or ethylaminopropyl, R 3 is an alkyl group with 1 to 5 carbon atoms, R 4 is an alkyl group or aryl group with 1 to 20 carbon atoms, and a is 0 or 1.

[0009] As a preferred embodiment of the present invention, the R 1 is an alkyl group with 1 to 5 carbon atoms.

[0010] As a preferred embodiment of the present invention, the R 1 is methyl.

[0011] As a preferred embodiment of the present invention, the R 2 is aminoethylpropyl.

[0012] As a preferred embodiment of the present invention, the R 3 is methyl or ethyl.

[0013] As a preferred embodiment of the present invention, the R 4 is methyl.

[0014] In a second aspect of the present invention, there is provided a method for preparing the photochromic material described in the first aspect of the present invention, comprising the following steps:

[0015] The compound shown in formula II containing an acrylate group is subjected to an addition reaction with the aminosilane shown in formula III to obtain the photochromic molecule;

[0016]

[0017] As an embodiment of the present invention, the molar ratio of the compound shown in formula II containing an acrylate group to the aminosilane shown in formula III is 1:(0.5 - 2).

[0018] As an embodiment of the present invention, the temperature of the addition reaction is 80 - 100 °C.

[0019] As an embodiment of the present invention, in the reaction system of the addition reaction, a catalyst is further added, and the catalyst includes trimethylamine or triethylamine.

[0020] As an embodiment of the present invention, the mass of the catalyst is 0 - 1% of the total mass of the compound shown in formula II containing an acrylate group and the aminosilane shown in formula III.

[0021] In a third aspect of the present invention, there is provided an application of the photochromic material described in the first aspect of the present invention. The photochromic material is used to prepare a photochromic product, and the matrix of the photochromic product includes at least one of organosilicon, polyurethane, epoxy resin, and acrylic resin.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] By chemically modifying the molecular structure of the photochromic material, the present invention can improve its compatibility in the organic matrix. Meanwhile, through the co-action among specific groups (such as active amino units, polar N,S-acetal units, and aromatic ring skeletons), it can further ensure a rapid photochromic reaction and adhesion to the substrate, further enhancing the color change stability and increasing the service life of the photochromic product. Detailed Embodiments

[0024] To better illustrate the purpose, technical solution, and advantages of the present invention, the following will further explain the present invention in combination with specific embodiments. However, the embodiments do not impose any form of limitation on the present invention. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field. Unless otherwise specified, the reagents and materials used in the present invention are commercially available.

[0025] In the present invention, among the technically characterized described in an open-ended manner, it includes a closed technical solution composed of the listed features, as well as an open technical solution containing the listed features.

[0026] In the present invention, regarding the numerical range, unless otherwise specified, the above numerical range is considered continuous and includes the minimum value and maximum value of this range, as well as each value between such minimum value and maximum value. Further, when the range refers to an integer, it includes each integer between the minimum value and maximum value of this range. In addition, when providing multiple ranges to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0027] For the reagents or instruments used in the present invention that are not indicated by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0028] In the first aspect of the present invention, an embodiment provides a photochromic material, and the photochromic material has a molecular structure as shown in Formula I:

[0029]

[0030] Formula I, R 1 is an alkyl group with 1 to 20 carbon atoms, R 2 is propylene, ethylenediaminepropyl, R 3 is an alkyl group with 1 to 5 carbon atoms, R 4 is an alkyl group or aryl group with 1 to 20 carbon atoms, and a is 0 or 1.

[0031] In the photochromic molecules of the present invention, there are active amino units for promoting adhesion, polar N,S-acetal units, and aromatic ring skeletons, which have adhesion durability; at the same time, the amino substitution in the molecules effectively reduces the basicity of primary amino groups. When used in organic matrices (especially silicone rubbers), it can improve the adhesion between silicone rubber and substrates, and enhance the persistence of water-resistant adhesion and heat-resistant adhesion of silicone rubber; moreover, polar groups such as N,S-acetal and aryl have good compatibility with plastic substrates such as acrylic and PET. Therefore, compared with traditional silane coupling agents, the above-mentioned silicon-based photochromic molecules have better adhesion effects on such substrates. Finally, the molecules of the photochromic material have a light response at a specific wavelength, which can be used for anti-counterfeiting and identification of materials. At the same time, through silicon-based modification, the compatibility between the photochromic molecules and silicone materials is improved, and the migration and loss of photochromic molecules caused by environmental factors such as light, heat, and water are reduced, thereby enhancing the anti-aging performance of the photochromic molecules.

[0032] In some embodiments of the present invention, the R 1 is an alkyl group with 1 to 5 carbon atoms. R 1 is connected to the N atom. A longer alkyl chain usually increases the distance between molecules, weakens the π-π stacking, thereby reducing the carrier transport efficiency and being unfavorable for the performance of light response and other properties; relatively speaking, a shorter alkyl chain may make the molecules more likely to maintain good dispersibility and higher crystallinity in solution or thin films, which helps to increase the light absorption coefficient of the molecules and enhance the light response efficiency. Therefore, R 1 is further preferably methyl.

[0033] In some embodiments of the present invention, R 2 is aminoethylaminopropyl. When the amino silane modifier has good compatibility with the organic matrix, the presence of the aliphatic chain can serve as a bridge connecting the photochromic structure and the organic matrix, enabling the photochromic molecules to more easily adjust their spatial conformations in the organic matrix, thus better adapting to the environment of the organic matrix and improving the dispersibility.

[0034] In some embodiments of the present invention, R 3 is methyl or ethyl. The presence of a shorter alkoxy chain can not only improve the compatibility between the photochromic molecules and the matrix, but also does not have a great impact on the configuration of the molecules with photochromic structures.

[0035] In some embodiments of the present invention, R 4 is methyl.

[0036] In the second aspect of the present invention, a preparation method of the photochromic material described in the first aspect of the present invention is provided, including the following steps:

[0037] The photochromic molecule can be obtained by the addition reaction of the compound shown in Formula II containing acrylate groups and the aminosilane shown in Formula III;

[0038]

[0039] In some embodiments of the present invention, the molar ratio of the compound shown in Formula II containing acrylate groups to the aminosilane shown in Formula III is 1:(0.5 - 2). The carbon-carbon double bond in the acrylate group in Formula II will undergo an addition reaction with —NH2 in Formula III. A slight excess of any component can promote the rapid progress of the addition reaction and increase the reaction rate.

[0040] In some embodiments of the present invention, the temperature of the addition reaction is 80 - 100 °C.

[0041] In some embodiments of the present invention, a catalyst is further added to the reaction system of the addition reaction. The catalyst includes trimethylamine or triethylamine; the mass of the catalyst is 0 - 1% of the total mass of the compound shown in Formula II containing acrylate groups and the aminosilane shown in Formula III.

[0042] In the third aspect of the present invention, an application of the photochromic material described in the first aspect of the present invention is provided. The photochromic material is used to prepare a photochromic product, and the matrix of the photochromic product includes at least one of silicone, polyurethane, epoxy resin, and acrylic resin.

[0043] The following are specific embodiments of the present invention.

[0044] Example 1

[0045] This example provides a photochromic material, which is prepared by a method comprising the following steps:

[0046] The acrylate-based photochromic molecule (Formula 1) and γ-aminopropyltriethoxysilane with a molar ratio of 1:1 are put into a reactor equipped with heating, stirring, and nitrogen protection, heated to 90 °C, and stirred at a speed of 100 r / min for 6 h under nitrogen protection to obtain the photochromic molecule. The structural formula is shown in Formula 2, denoted as SiPCM1;

[0047]

[0048] Example 2

[0049] This example provides a photochromic material, which is prepared by a method comprising the following steps:

[0050] The acrylate-based photochromic molecule (Formula 3) and β-aminoethyl γ-aminopropyltrimethoxysilane with a molar ratio of 1:1.2 were put into a reactor equipped with heating, stirring, and nitrogen protection. Trimethylamine with a mass fraction of 0.5% (based on the total mass of the acrylate-based photochromic molecule and β-aminoethyl γ-aminopropyltrimethoxysilane) was added. The temperature was raised to 80 °C, and under nitrogen protection, the mixture was stirred at a speed of 100 r / min for 3 h. Trimethylamine was removed under reduced pressure to obtain the silicon-based photochromic molecule, denoted as SiPCM2; it was cooled, discharged, and stored sealed for later use.

[0051] Examples 3-9, Comparative Examples 1-3

[0052] A series of photochromic materials were provided and prepared according to the method of Example 1. The difference from Example 1 was that by changing the types of raw materials and adaptively adjusting parameters such as reaction temperature and time, photochromic materials with different structural formulas were prepared. The structural formula of the photochromic material was as shown in Formula I, and the values of R 1 , R 2 , R 3 , R 4 and a, etc. are shown in Table 1 in detail:

[0053]

[0054] Performance testing

[0055] The photochromic materials of the above examples and comparative examples were used as photochromic additives and added to organosilicon to prepare anti-counterfeiting organosilicon. The specific composition and preparation method are as follows:

[0056] 100 parts by weight of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 20000 mPa·s at 25 °C, 40 parts by weight of calcium carbonate treated with stearic acid (particle size 0.06 μm, and the weight of stearic acid used was 2.5% of the weight of untreated calcium carbonate), 7 parts by weight of dimethyl silicone oil with a viscosity of 350 mPa·s at 25 °C, 6 parts by weight of methyltributanone oxime silane, 1 part by weight of vinyltributanone oxime silane, 0.6 part by weight of aminopropyltriethoxysilane, 0.3 part by weight of glycidyl ether propyltrimethoxysilane, 0.03 part by weight of the photochromic material prepared in the above example or comparative example, and 0.1 part by weight of dibutyltin dilaurate were defoamed and mixed in a universal mixer to obtain anti-counterfeiting organosilicon;

[0057] Under 365 nm light irradiation, the color-changing performance of the organosilicon added with the photochromic materials of the above examples and comparative examples was observed and tested; the color-changing response time was observed, as well as the retention rate of the color-changing degree after 500 light responses.

[0058] Table 1

[0059]

[0060] The above results show that:

[0061] From the comparison results of the above examples and comparative examples, it can be seen that by chemically modifying the molecular structure of the photochromic material, its compatibility in the organic matrix can be improved. At the same time, through the co-action between specific groups (such as active amino units, polar N,S-acetal units, and aromatic ring skeletons), especially the groups in the photochromic molecule will interact with each other and affect the reaction activity of each other, thereby being able to improve the color change rate of the photochromic molecule.

[0062] The color change degree retention rate of the photochromic molecules of the present invention is above 85% after 500 times of light irradiation, and the color change response time is within 10 s, and can be as low as 2 s.

[0063] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A photochromic material, characterized in that, It has a molecular structure shown in Formula I: In formula I, R 1 is an alkyl group having 1 to 20 carbon atoms, R 2 is propylene, ethylenepropylamine, R 3 is an alkyl group having 1 to 5 carbon atoms, R 4 is an alkyl group having 1 to 20 carbon atoms or an aryl group, and a is 0 or 1.

2. The photochromic material according to claim 1, characterized in that, The R 1 is an alkyl group having 1 to 5 carbon atoms.

3. The photochromic material according to claim 2, wherein The said R 1 is methyl.

4. The photochromic material according to claim 1, characterized in that, The R 2 is ethylenediaminopropyl.

5. The photochromic material according to claim 1, wherein The R 3 is methyl or ethyl.

6. The photochromic material according to claim 1, characterized in that, The said R 4 is methyl.

7. The preparation method of the photochromic material according to any one of claims 1 to 6, characterized in that, It includes the following steps: The compound shown in Formula II containing an acrylate group undergoes an addition reaction with the aminosilane shown in Formula III to obtain the photochromic molecule; 8. The preparation method of the photochromic material according to claim 7, characterized in that, The molar ratio of the compound shown in Formula II containing an acrylate group to the aminosilane shown in Formula III is 1:(0.5 - 2).

9. The preparation method of the photochromic material according to claim 7, characterized in that It satisfies at least one of the following characteristics: (1) The temperature of the addition reaction is 80 - 100 °C; (2) In the reaction system of the addition reaction, a catalyst is further added, and the catalyst includes trimethylamine or triethylamine; the mass of the catalyst is 0 - 1% of the total mass of the compound shown in Formula II containing an acrylate group and the aminosilane shown in Formula III.

10. Use of the photochromic material according to any one of claims 1 to 6, characterized in that, The silicon-based photochromic material is used to prepare a photochromic product, and the matrix of the photochromic product includes at least one of silicone, polyurethane, epoxy resin, and acrylic resin.

Images