Ultraviolet chromogenic acrylate monomer, ultraviolet chromogenic UV adhesive and application of ultraviolet chromogenic acrylate monomer and ultraviolet chromogenic UV adhesive

Abstract

The invention relates to an ultraviolet developing acrylate monomer, an ultraviolet developing UV adhesive and application, and belongs to the technical field of adhesives. The ultraviolet developing acrylate monomer can absorb the wavelength of 200 nm to 385 nm, and efficient preparation of the ultraviolet developing UV adhesive is achieved. The ultraviolet developing acrylate monomer is used as a free radical polymerization monomer to participate in polymerization of the UV adhesive to form a uniform UV adhesive block or adhesive film; the problems that common fluorescent dye additives are high in adding proportion, easy to migrate and diffuse and the like can be solved. In addition, due to the fact that the formed adhesive film can absorb light with the wavelength of 200-385 nm, the waterproof, dustproof and antifouling functions are achieved, and electronic components below the adhesive film can be prevented from being damaged by ultraviolet rays.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, and in particular to ultraviolet-developing acrylate monomers, ultraviolet-developing UV adhesives, and their applications. Background Technology

[0002] UV-developing adhesives typically contain fluorescent dyes that emit visible fluorescence under ultraviolet light. During the coating process, the adhesive forms a thin film; under ultraviolet light, the fluorescent dyes on the adhesive emit bright fluorescence, helping operators determine the uniformity and quality of the coating. Currently available UV-developing adhesives have two major drawbacks: (1) the addition of inorganic UV colorants, such as metal sulfides or rare earth oxides, results in high prices, environmental unfriendliness, and interference with the adhesive's inherent properties; (2) the addition of organic UV colorants, such as fluorescent dye molecules, leads to phase separation and fogging after curing.

[0003] Therefore, designing an integrated molecular design that combines benzotriazole and acrylate is of research significance, and further research on its application in UV colorimetric adhesives is of great importance. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides ultraviolet (UV) color-developing acrylate monomers, UV color-developing adhesives, and their applications. The UV color-developing adhesive of this invention is suitable for applications such as rapid detection of conformal UV adhesives.

[0005] This invention is achieved through the following technical solution:

[0006] The first object of the present invention is to provide a UV-emitting acrylate monomer, said UV-emitting acrylate monomer being selected from one or more of the following compounds:

[0007] , or .

[0008] In one embodiment of the present invention, the absorption wavelength of the ultraviolet color-developing acrylate monomer is 200 nm-385 nm.

[0009] In one embodiment of the present invention, the ultraviolet color-developing acrylate monomer uses benzotriazole as the optically active core and achieves dual functionality through the following modular modification:

[0010] Anchoring module: Polymerizable double bonds (acrylate / allyl ether / siloxane) are introduced at the para-position of the benzene ring and at the nitrogen position 2 of benzotriazole, respectively or simultaneously, and embedded into the UV polymer network through covalent bonding, thereby solving the problem of phase separation of organic UV colorimetric agents.

[0011] In one embodiment of the present invention, the method for synthesizing the ultraviolet-based colorimetric acrylate monomer is as follows:

[0012] (1) Constructing the optical core: Halogenated benzotriazole is coupled with arylboronic acid containing phenolic hydroxyl, alcoholic hydroxyl or alkyl substituted (Suzuki coupling) to obtain benzotriazole intermediates with dihydroxy aryl functionalization and dialkyl aryl functionalization;

[0013] (2) Functionalization modification: Polymerizable double bonds are introduced into the benzotriazole intermediate obtained in the previous step through esterification and etherification;

[0014] (3) Crosslinking and curing: The compound obtained in step (2) is copolymerized with acrylate monomers and resin to form a three-dimensional network, completing molecular anchoring and obtaining UV-emitting acrylate monomers.

[0015] A second objective of this invention is to provide the application of UV-emitting acrylate monomers in the preparation of UV-emitting adhesives.

[0016] A third object of the present invention is to provide a UV-developing color-developing adhesive, wherein, by weight, the UV-developing color-developing adhesive comprises the following components:

[0017] The composition includes 35-65 parts of polyurethane carbon-carbon double bond acrylic resin, 0.0001-0.03 parts of UV-developing acrylate monomers, 20-45 parts of functional monomers containing active hydroxyl groups, 5-15 parts of functional monomers, 3-10 parts of fumed silica, and 0.5-3 parts of photoinitiator. The fumed silica is used to adjust the thixotropy of the UV adhesive.

[0018] In one embodiment of the present invention, the active hydroxyl functional monomer is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate.

[0019] In one embodiment of the present invention, the functional monomer is selected from one or more of acrylic acid, methacrylic acid, N-hydroxymethylacrylamide, glycidyl acrylate and N,N-dimethylacrylamide.

[0020] In one embodiment of the present invention, the polyurethane-carbon-carbon double bond-containing acrylic resin is obtained through the following steps:

[0021] Under a nitrogen atmosphere, the first monomer, the second monomer, and the third monomer are mixed in a solvent and heated; an initiator is added to react, and after cooling, an intermediate product is obtained; a catalyst and isocyanate are then added to the intermediate product to react and obtain the polyurethane-containing carbon-carbon double bond acrylic resin; the solvent is ethyl acetate.

[0022] Specifically, the polyurethane-containing carbon-carbon double bond acrylic resin is obtained through the following steps:

[0023] S1. Under a nitrogen atmosphere, mix 30-85 parts by weight of the first monomer, 5-15 parts by weight of the second monomer, and 6-25 parts by weight of the third monomer, and heat to 60-70°C to obtain a mixture.

[0024] S2: Add 0.02-0.5 parts of initiator to the mixture obtained in S1, react at 76-90℃ for 2-8 h, and then cool to 40-60℃ to obtain the intermediate product;

[0025] S3: Add 0.01-0.5 parts of catalyst and 5-30 parts of isocyanate to the intermediate product obtained in S2, and react for 2-6 h to obtain the acrylic resin containing polyurethane carbon-carbon double bonds.

[0026] The first monomer is selected from one or more of methyl acrylate, butyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and morpholine acrylate;

[0027] The second monomer is selected from one or more of acrylic acid, methacrylic acid, N-hydroxymethylacrylamide, glycidyl acrylate and N,N-dimethylacrylamide;

[0028] The third monomer is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

[0029] The photoinitiator is selected from one or more of benzoyl dimethyl ether, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0030] The catalyst is selected from one or more of dioctyltin laurate, dibutyltin dilaurate, bismuth chloride, and bismuth oxide.

[0031] The isocyanate is selected from ethyl isocyanate acrylate.

[0032] In one embodiment of the present invention, the photoinitiator is selected from one or more of benzoyl dimethyl ether, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0033] The fourth objective of this invention is to provide a method for preparing the aforementioned ultraviolet-based color-developing UV adhesive, comprising the following steps:

[0034] An acrylic resin containing polyurethane carbon-carbon double bonds, a functional monomer containing active hydroxyl groups, a functional monomer, fumed silica, a UV-emitting acrylate monomer, and a photoinitiator are stirred and dispersed to obtain a UV-emitting adhesive.

[0035] The fifth objective of this invention is to provide the application of the ultraviolet color-developing UV adhesive in PCBs, FPC flexible boards, or anti-counterfeiting labels.

[0036] The technical solution of the present invention has the following advantages compared with the prior art:

[0037] This invention provides UV-emitting color-developing acrylate monomers, UV-emitting color-developing UV adhesives, and their applications. Because UV-emitting color-developing acrylate monomers absorb wavelengths of 200nm-385nm, they enable the efficient preparation of UV-emitting color-developing adhesives. These monomers, acting as free radical polymerizers, participate in the polymerization of UV adhesives, forming uniform UV adhesive blocks or films. This invention solves the problems of high addition ratios and easy migration and diffusion associated with common fluorescent dye additives.

[0038] In addition, since the formed film absorbs light with wavelengths of 200 nm to 385 nm, it not only provides waterproof, dustproof, and stain-proof functions, but also protects the electronic components underneath the film from damage caused by ultraviolet rays. Attached Figure Description

[0039] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0040] Figure 1 The UV and fluorescence emission spectra of 4-(4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazol-2-yl)butyl acrylate (14) in this invention are shown.

[0041] Figure 2 The UV and fluorescence emission spectra of 4-(4,7-bis(4-tert-butylphenyl)-2H-benzo[d][1,2,3]triazol-2-yl)butyl acrylate (15) in this invention;

[0042] Figure 3 The UV and fluorescence emission spectra of (2-(4-(acryloyloxy)butyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)bis(4,1-phenylene)diacrylate (16) in this invention are shown.

[0043] Figure 4 This is a diagram showing the UV-visible adhesive prepared in Example 10 of this invention under weak ultraviolet light.

[0044] Figure 5 These are images showing the UV adhesive prepared in Example 10 of this invention after curing (A) and after weak ultraviolet irradiation (B).

[0045] Figure 6This is a diagram showing the UV-visible adhesive prepared in Example 12 of this invention under weak ultraviolet light.

[0046] Figure 7 This is a diagram showing the UV-visible adhesive prepared in Example 12 of this invention after curing under weak ultraviolet light irradiation;

[0047] Figure 8 This is a diagram showing the UV-visible adhesive prepared in Example 13 of this invention under weak ultraviolet light.

[0048] Figure 9 These are images showing the UV adhesive prepared in Example 13 of this invention after curing (A) and after weak ultraviolet irradiation (B). Detailed Implementation

[0049] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0050] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.

[0051] Example 1

[0052]

[0053] 4-Chloro-1-butanol (1) (5.428 g, 50 mmol) was dissolved in diethyl ether (50 mL), two drops of concentrated hydrochloric acid were added, and the mixture was stirred and cooled at 0 °C. Then, 3,4-dihydro-2H-pyran (6.3 mL) was added, and the mixture was stirred overnight at room temperature. After the reaction was complete, the mixture was neutralized with sodium bicarbonate and extracted with diethyl ether. The organic layer was washed successively with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give 8.460 g of a colorless oil: 4-chloro-1-(2-tetrahydropyranoxy)butane (2) (yield 88%), which was used directly in the next reaction without further purification.

[0054] Example 2

[0055]

[0056] 4,7-Dibromo-benzotriazole (3) (27.692 g, 100 mmol) and potassium carbonate (13.8 g) were placed in DMF (200 mL), and 4-chloro-1-(2-tetrahydropyranoxy)butane (2) (21.195 g, 110 mmol) was added. The mixture was heated under reflux for 12 hours. After cooling, the reaction mixture was partitioned with water and chloroform. The organic layer was concentrated and purified by preparative thin-layer chromatography (developing solvent: chloroform / methanol 98:2). After elution and evaporation of the solvent, compound 4,7-dibromo-2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-2H-benzo[d][1,2,3]triazole (4) (19.491 g, 45% yield) was obtained.

[0057] The 1H NMR spectrum of 4,7-dibromo-2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-2H-benzo[d][1,2,3]triazole(4) is as follows: 1 H NMR (400 MHz, CDCl3) δ 7.52 (s, 2H), 4.80 (t, J = 7.2 Hz,2H), 4.50 (dd, J = 8.6, 1.6 Hz, 1H), 3.60 – 3.70 (m, 4H), 2.21 – 2.32 (m,2H), 1.63 – 1.83 (m, 8H).

[0058] Example 3

[0059]

[0060] Take 4,7-dibromo-2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-2H-benzo[d][1,2,3]triazole (4) (50 mmol, 21.657 g), potassium carbonate (150 mmol, 20.752 g), tetra(triphenylphosphine)palladium (3.0 mmol, 12.450 g), and p-methylphenylboronic acid (5) (150 mmol, 20.394 g), add them to a Schlenk tube, purge with nitrogen, add a mixed solvent of 1,4-dioxane and water (200 mL, volume ratio 5:1), and stir and heat at 120°C for 6 hours. h, after the reaction was completed, ethyl acetate and saturated ammonium chloride solution were added and extracted to obtain the organic phase. Anhydrous sodium sulfate was added to remove water, filtered, and concentrated to obtain 2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazole (6), which was directly used in the next step of the reaction.

[0061] The obtained 2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazole (6) was dissolved in 200 mL of methanol, p-toluenesulfonic acid (10.332 g, 60 mmol) was added, the mixture was stirred at room temperature for 12 h, and the solution was concentrated by column chromatography to obtain 4-(4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazole-2-yl)but-1-ol (7) (12,064 g, two-step reaction yield 65%).

[0062] The 1H NMR spectrum of the intermediate 4-(4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazol-2-yl)but-1-ol (7) is as follows: 1 H NMR (400 MHz, CDCl3) δ 8.01 (d, J = 8.2 Hz, 4H), 7.65 (s, 2H), 7.58 (d, J = 8.2 Hz, 4H), 4.88 (t, J = 7.2 Hz, 2H), 3.69 (t, J = 6.8 Hz, 2H), 2.25 – 2.35 (m, 2H), 2.15 (s, 6H), 1.65 – 1.75 (m, 2H).

[0063] Example 4

[0064]

[0065] Take 4,7-dibromo-2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-2H-benzo[d][1,2,3]triazole (4) (50 mmol, 21.657 g), potassium carbonate (150 mmol, 20.752 g), tetra(triphenylphosphine)palladium (3.0 mmol, 12.450 g), and p-tert-butylphenylboronic acid (8) (150 mmol, 26.706 g), add them to a Schlenk tube, purge with nitrogen, and then add a mixed solvent of 1,4-dioxane and water (200 mmol). mL (volume ratio 5:1), stirred and heated at 120 degrees Celsius for 6 h. After the reaction was completed, ethyl acetate and saturated ammonium chloride solution were added and extracted to obtain the organic phase. Anhydrous sodium sulfate was added to remove water, filtered, and concentrated to obtain 4,7-bis[4-(tert-butyl)phenyl]-2-[4-((tetrahydro-2H-pyran-2-yl)oxy)butyl]-2H-benzo[d][1,2,3]triazole (9), which was directly used in the next step of the reaction.

[0066] The obtained 4,7-bis[4-(tert-butyl)phenyl]-2-[4-((tetrahydro-2H-pyran-2-yl)oxy)butyl]-2H-benzo[d][1,2,3]triazole (9) was dissolved in 200 mL of methanol, p-toluenesulfonic acid (10.332 g, 60 mmol) was added, and the mixture was stirred at room temperature for 12 h. The product 4-(4,7-bis(4-tert-butylphenyl)-2H-benzo[d][1,2,3]triazole-2-yl)but-1-ol (10) (15.492 g, two-step reaction yield 68%) was obtained by column chromatography.

[0067] The 1H NMR spectrum of product 4-(4,7-bis(4-tert-butylphenyl)-2H-benzo[d][1,2,3]triazol-2-yl)but-1-ol (10) is as follows: 1 H NMR (400 MHz, CDCl3) δ 7.99 (d, J = 8.5 Hz, 4H), 7.62 (s, 2H), 7.55 (d, J = 8.5 Hz, 4H), 4.86 (t, J = 7.1 Hz, 2H), 3.71 (t, J = 6.3 Hz, 2H), 2.21 – 2.32 (m, 2H), 1.63 – 1.73 (m, 2H), 1.41 (s, 18H).

[0068] Example 5

[0069]

[0070] Take 4,7-dibromo-2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-2H-benzo[d][1,2,3]triazole (4) (50 mmol, 21.657 g), potassium carbonate (150 mmol, 20.752 g), tetra(triphenylphosphine)palladium (3.0 mmol, 12.450 g), and p-hydroxyphenylboronic acid (11) (150 mmol, 20.690 g), add them to a Schlenk tube, purge with nitrogen, and then add a mixed solvent of 1,4-dioxane and water (200 g). mL (volume ratio 5:1), stirred and heated at 120 degrees Celsius for 6 h. After the reaction was completed, ethyl acetate and saturated ammonium chloride solution were added and extracted to obtain the organic phase. Anhydrous sodium sulfate was added to remove water, filtered, and concentrated to obtain 4,4'-(2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-2H-benzo[d][1,2,3]triazol-4,7-diyl)diphenol (12), which was directly used in the next step of the reaction.

[0071] The obtained 4,4'-(2-(4-((tetrahydro-2H-pyran-2-yl)oxy)butyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)diphenol (12) was dissolved in 200 mL of methanol, p-toluenesulfonic acid (10.332 g, 60 mmol) was added, and the mixture was stirred at room temperature for 12 h. The product 4,4'-(2-(4-hydroxybutyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)diphenol (13) (15.492 g, two-step reaction yield 68%) was obtained by column chromatography.

[0072] The 1H NMR spectrum of product 4,4'-(2-(4-hydroxybutyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)diphenol (13) is as follows: 1 H NMR (400 MHz, CDCl3) δ 9.20 (s, 2H), 8.01 (d, J = 6.8 Hz, 4H), 7.42 (s, 2H), 7.35 (d, J = 6.8 Hz, 4H), 4.82 (t, J = 7.0 Hz, 2H), 3.75 (t, J= 6.3 Hz, 2H), 2.55 (s, 1H), 2.19 – 2.29 (m, 2H), 1.60 – 1.70 (m, 2H).

[0073] Example 6

[0074]

[0075] 4-(4,7-bis(4-methylphenyl)-2H-benzo[d][1,2,3]triazol-2-yl)but-1-ol (7) (10 mmol, 3.715 g), dichloromethane (50 mL), triethylamine (12 mmol, 1.214 g), and acryloyl chloride (12 mmol, 1.086 g) were added to a round-bottom flask and heated under nitrogen protection by reflux and stirring for 6 h. After the reaction was completed, ethyl acetate and saturated ammonium chloride solution were added and the mixture was extracted to obtain the organic phase. Anhydrous sodium sulfate was added to remove water, and the mixture was filtered and separated by column chromatography to obtain 3.447 g of 4-(4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazol-2-yl)butyl acrylate (14), with a separation yield of 81%. The UV and fluorescence emission spectra of product 4-(4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazol-2-yl)butyl acrylate are as follows: Figure 1 As shown.

[0076] The proton NMR spectrum of the product 4-(4,7-di-p-tolyl-2H-benzo[d][1,2,3]triazol-2-yl)butyl acrylate (14) is as follows: 1 H NMR (400 MHz, CDCl3) δ 8.00 (d, J = 8.2 Hz, 4H), 7.56 (s,2H), 7.53 (d, J = 8.2 Hz, 4H), 6.30 (dd, J = 17.2, 1.4 Hz, 1H), 6.04 (dd, J =17.2, 10.6 Hz, 1H), 5.70 (dd, J = 10.6, 1.4 Hz, 1H), 4.70 (t, J = 7.2 Hz, 2H), 4.13 (t, J = 6.6 Hz, 2H), 2.15-2.20 (m, 2H), 2.12 (s, 6H),1.60 – 1.81(m, 2H).

[0077] Example 7

[0078]

[0079] 4-(4,7-bis(4-tert-butylphenyl)-2H-benzo[d][1,2,3]triazol-2-yl)but-1-ol (10) (10 mmol, 4.556 g), dichloromethane (50 mL), triethylamine (12 mmol, 1.214 g), and acryloyl chloride (12 mmol, 1.086 g) were added to a round-bottom flask and heated under nitrogen protection by reflux and stirring for 6 h. After the reaction was completed, ethyl acetate and saturated ammonium chloride solution were added and the mixture was extracted to obtain the organic phase. Anhydrous sodium sulfate was added to remove water, and the mixture was filtered and separated by column chromatography to obtain 4.230 g of 4-(4,7-bis(4-tert-butylphenyl)-2H-benzo[d][1,2,3]triazol-2-yl)butyl acrylate (15), with a separation yield of 83%. The UV and fluorescence emission spectra of 4-(4,7-bis(4-tert-butylphenyl)-2H-benzo[d][1,2,3]triazol-2-yl)butylacrylate are as follows: Figure 2 As shown.

[0080] The proton NMR spectrum of the product 4-(4,7-bis(4-tert-butylphenyl)-2H-benzo[d][1,2,3]triazol-2-yl)butylacrylate (15) is as follows: 1H NMR (400 MHz, CDCl3) δ 7.99 (d, J = 8.4 Hz, 4H), 7.55(s, 2H), 7.51 (d, J = 8.4 Hz, 4H), 6.34 (dd, J = 17.3, 1.4 Hz, 1H), 6.04 (dd,J = 17.3, 10.4 Hz, 1H), 5.70 (dd, J = 10.4, 1.4 Hz, 1H), 4.75 (t, J = 7.1 Hz, 2H), 4.15 (t, J = 6.4 Hz, 2H), 2.16-2.21 (m, 2H), 1.62 – 1.82 (m, 2H), 1.36 (s, 18H).

[0081] Example 8

[0082]

[0083] Take 4,4'-(2-(4-hydroxybutyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)diphenol (13) (10 mmol, 3.754 g), dichloromethane (50 mL), triethylamine (35 mmol, 3.541 g), and acryloyl chloride (35 mmol, 3.168 g) into a round-bottom flask. Under nitrogen protection, reflux and stir for 6 h. After the reaction is complete, extract with ethyl acetate and saturated ammonium chloride solution to obtain the organic phase. Remove water with anhydrous sodium sulfate, filter, and separate by column chromatography to obtain 4.017 g of (2-(4-(acryloyloxy)butyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)bis(4,1-phenylene)diacrylate (16), with a separation yield of 75%. The UV and fluorescence emission spectra of (2-(4-(acryloyloxy)butyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)bis(4,1-phenylene)diacrylate are as follows: Figure 3 As shown.

[0084] The proton NMR spectrum of the product (2-(4-(acryloyloxy)butyl)-2H-benzo[d][1,2,3]triazole-4,7-diyl)bis(4,1-phenylene)diacrylate (16) is as follows: 1H NMR (400 MHz, CDCl3) δ 8.11 (d, J =6.8 Hz, 4H), 7.50 (s, 2H), 7.32 (d, J = 6.8 Hz, 4H), 6.38-6.65 (m, 3H), 6.42 (dd, J = 16.8, 10.8 Hz, 2H), 6.05 (dd, J = 17.0, 10.4 Hz, 1H), 5.37-5.65(m, 3H), 4.72 (t, J = 7.2 Hz, 2H), 4.18 (t, J = 6.6 Hz, 2H), 2.15-2.22 (m,2H), 1.60 – 1.80 (m, 2H).

[0085] Example 9

[0086] This embodiment provides a UV adhesive that develops ultraviolet light. By weight, the UV adhesive comprises the following components:

[0087] The mixture contains 50 parts of polyurethane carbon-carbon double bond acrylic resin, 35 parts of hydroxyethyl acrylate, 10 parts of N,N-dimethylacrylamide, 5 parts of fumed silica, 0.3 parts of UV-developing acrylate monomer (compound 14 prepared in Example 6), 0.5 parts of 184 photoinitiator (1-hydroxycyclohexylphenyl ketone), and 0.5 parts of photoinitiator TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide).

[0088] The preparation method of the UV adhesive in this embodiment is as follows:

[0089] (1) Preparation of acrylic resin containing polyurethane carbon-carbon double bonds (refer to Chinese Patent CN120310441B):

[0090] 40 parts of isooctyl acrylate, 30 parts of butyl acrylate, 15 parts of methyl methacrylate, 10 parts of hydroxyethyl acrylate, 5 parts of N,N-dimethylacrylamide, and 100 parts of ethyl acetate were mixed evenly. Under a nitrogen atmosphere, the mixture was stirred and heated to 66°C. 0.02 parts of azobisisobutyronitrile (AIBN) initiator were added, and the mixture was kept at this temperature for 2 hours. Then, 0.01 parts of AIBN were added, and the mixture was heated to 80°C and kept at this temperature for 2 hours. Finally, the mixture was cooled to 40°C.

[0091] Add 0.02 parts of dibutyltin dilaurate to the above-treated reaction solution, stop the nitrogen gas flow, and under stirring conditions, add a mixture of 12.15 parts of ethyl isocyanate and 12.15 parts of ethyl acetate dropwise to the reaction solution over half an hour. Keep warm for 6 hours, cool down and discharge to obtain an acrylic resin containing polyurethane carbon-carbon double bonds.

[0092] (2) Take 50 parts of the polyurethane carbon-carbon double bond acrylic resin obtained in step (1), 35 parts of hydroxyethyl acrylate, 10 parts of N,N-dimethylacrylamide, 5 parts of fumed silica, 0.3 parts of UV-developing acrylate monomer, 0.5 parts of 184 photoinitiator, and 0.5 parts of photoinitiator TPO. Disperse the mixture by double planetary stirring for 3 hours to obtain a UV-developing adhesive.

[0093] Example 10

[0094] This embodiment provides a UV adhesive with ultraviolet color development, similar to that of Example 9, except that it contains 0.1 parts of a UV-developing acrylate monomer (monomer compound 14 obtained in Example 6).

[0095] The preparation method is similar to that in Example 9.

[0096] Example 11

[0097] This embodiment provides a UV adhesive with ultraviolet color development, similar to Example 9, except that it contains 0.05 parts of ultraviolet color-developing acrylate monomer (monomer compound 14 obtained in Example 6).

[0098] The preparation method is similar to that in Example 9.

[0099] Example 12

[0100] This embodiment provides a UV adhesive with ultraviolet color development, similar to Example 9, except that it contains 0.05 parts of ultraviolet color-developing acrylate monomer (monomer compound 15 obtained in Example 7).

[0101] The preparation method is similar to that in Example 9.

[0102] Example 13

[0103] This embodiment provides a UV adhesive with ultraviolet color development, similar to Example 9, except that it contains 0.05 parts of UV-developing acrylate monomer (monomer compound 16 obtained in Example 8).

[0104] The preparation method is similar to that in Example 9.

[0105] Test case

[0106] (1) The UV adhesive prepared in Example 10 showed a strong blue color under ultraviolet light, as shown in the following results. Figure 4 As shown. Figure 4 Displayed under weak ultraviolet conditions (365 nm, light intensity 5 mW / cm²). 2Uncured UV adhesive liquid can develop color, with the color-developing monomers evenly distributed; after curing via strong UV-initiated free radical polymerization, the adhesive block can also absorb ultraviolet light and develop color. This indicates that UV-colored adhesives can absorb ultraviolet light and display blue color both before and after polymerization.

[0107] (2) The UV adhesive prepared in Example 10 was cured under a 365 nm UV lamp (18 W 365 nm wavelength LED lamp, light intensity 100 mW / cm², curing time 10 seconds) to obtain an adhesive block. Figure 5 After curing, the entire adhesive block displays a uniform and very obvious blue light under UV light.

[0108] (3) Take 2 g of the above-mentioned adhesive block and place it in a 100 mL round-bottom flask. Soak it in 20 mL of ethyl acetate for 72 h. The ethyl acetate extraction experiment showed that there was no residue of the UV-developing monomer, indicating that the UV-developing acrylate monomer (monomer compound 14) fully participated in the polymerization during the UV polymerization process. By using the molecular structure based on the "optical core-anchored chain" and the free radical polymerization of acrylates initiated by the photoinitiator, the preparation of UV adhesive that is easy to detect under ultraviolet light was realized.

[0109] The UV-emitting adhesive prepared in Example 12 was tested according to the above method, and the display image under weak ultraviolet light is shown below. Figure 6 As shown in the image, the product appears after curing and exposure to weak ultraviolet light. Figure 7 As shown.

[0110] The UV-emitting adhesive prepared in Example 13 was tested according to the above method, and the display image under weak ultraviolet light is shown below. Figure 8 As shown, the results after curing and after weak ultraviolet irradiation are as follows. Figure 9 As shown.

[0111] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A UV-developing acrylate monomer, characterized in that, The ultraviolet-emitting acrylate monomers are selected from one or more of the following compounds: , or .

2. The UV-emitting acrylate monomer according to claim 1, characterized in that, The absorption wavelength of the ultraviolet color-developing acrylate monomer is 200 nm-385 nm.

3. Application of UV-developing acrylate monomers in the preparation of UV-developing adhesives.

4. A UV-developing adhesive, characterized in that, The UV-developing adhesive comprises the following components in parts by weight: The product contains 35-65 parts of polyurethane carbon-carbon double bond acrylic resin, 0.0001-0.03 parts of UV-developing acrylate monomer as described in claim 1 or 2, 20-45 parts of functional monomer containing active hydroxyl groups, 5-15 parts of functional monomer, 3-10 parts of fumed silica, and 0.5-3 parts of photoinitiator.

5. The UV-developing adhesive according to claim 4, characterized in that, The active hydroxyl functional monomer is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

6. The UV-developing adhesive according to claim 4, characterized in that, The functional monomer is selected from one or more of acrylic acid, methacrylic acid, N-hydroxymethylacrylamide, glycidyl acrylate and N,N-dimethylacrylamide.

7. The UV-developing adhesive according to claim 4, characterized in that, The polyurethane-carbon double bond-containing acrylic resin is obtained through the following steps: Under a nitrogen atmosphere, the first monomer, the second monomer, and the third monomer are mixed in a solvent and heated; an initiator is added to react, and after cooling, an intermediate product is obtained; then a catalyst and isocyanate are added to the intermediate product to react and obtain the polyurethane carbon-carbon double bond-containing acrylic resin. The first monomer is selected from one or more of methyl acrylate, butyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and morpholine acrylate; The second monomer is selected from one or more of acrylic acid, methacrylic acid, N-hydroxymethylacrylamide, glycidyl acrylate and N,N-dimethylacrylamide; The third monomer is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

8. The UV-developing adhesive according to claim 4, characterized in that, The photoinitiator is selected from one or more of benzoyl dimethyl ether, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

9. A method for preparing the ultraviolet color-developing UV adhesive according to any one of claims 4-8, characterized in that, Includes the following steps: An acrylic resin containing polyurethane carbon-carbon double bonds, a functional monomer containing active hydroxyl groups, a functional monomer, fumed silica, a UV-emitting acrylate monomer, and a photoinitiator are stirred and dispersed to obtain a UV-emitting adhesive.

10. The application of the ultraviolet color-developing UV adhesive according to any one of claims 4-8 in PCBs, FPC flexible boards or anti-counterfeiting labels.

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