Light conversion agent having asymmetric structure, light conversion adhesive film and preparation method therefor

Abstract

The present invention belongs to the technical field of light conversion adhesive films, and in particular relates to a light conversion agent having an asymmetric structure, a light conversion adhesive film and a preparation method therefor. Benzotriazole serves as a matrix of the light conversion agent, and an asymmetric aromatic ring is introduced to the two sides of a benzene ring, wherein the asymmetric aromatic ring comprises a heteroaryl group on one side and a benzene ring on the other side. As for the light conversion agent having an asymmetric structure, the light conversion adhesive film and the preparation method therefor of the present invention, benzotriazole serves as a matrix, and an asymmetric heteroaryl and benzene ring are introduced to the two sides of the benzene ring. The heteroaryl, such as a thiophene aromatic ring, has a higher electron density and a superior carrier mobility compared with a benzene ring; in addition, the asymmetric structure can make the light conversion wavelength of the light conversion agent have a wider space for regulation and control, and light conversion within different wavelength ranges can also be further achieved by regulating and controlling the light-emitting units on the two sides, thereby efficiently utilizing sunlight.

Description

Asymmetric structure light conversion agent, light conversion adhesive film and preparation method thereof Technical Field

[0001] The present invention belongs to the technical field of light-converting adhesive films, and in particular relates to an asymmetric structure light-converting agent, a light-converting adhesive film and a preparation method thereof. Background Art

[0002] Generally speaking, mid-wavelength visible light and near-infrared light are absorbed by the main body of solar cells, and the excited carriers easily enter the external circuit, resulting in high quantum efficiency. However, for ultraviolet light with wavelengths less than 400nm, solar cells have low utilization efficiency. Furthermore, the presence of ultraviolet light in sunlight can also shorten the service life of photovoltaic devices.

[0003] The light-converting film can effectively absorb the ultraviolet light in the sunlight, preventing it from damaging the service life of the photovoltaic device; at the same time, it can convert the ultraviolet light into usable visible light, thereby improving the photoelectric conversion efficiency of the photovoltaic device.

[0004] The luminescent cores of existing light conversion agents all have symmetrical structures. However, the symmetrical structure of the molecules has a very narrow range of control over the converted light wavelength and cannot efficiently utilize sunlight.

[0005] Therefore, there is an urgent need for a light conversion agent that can regulate a wider range of light conversion wavelengths.

[0006] Summary of the Invention

[0007] The present invention provides an asymmetric structure light conversion agent, a light conversion adhesive film and a preparation method thereof, so as to solve the technical problem that the light conversion wavelength control range of the existing symmetric structure light conversion agent is too narrow.

[0008] In order to solve the above technical problems, the present invention provides an asymmetric structure light conversion agent, comprising: the light conversion agent is benzotriazole as a matrix, and asymmetric aromatic rings are introduced on both sides of the benzene ring; the asymmetric aromatic ring includes a heteroaryl group on one side and a benzene ring on the other side.

[0009] In yet another aspect, the present invention further provides a method for preparing the aforementioned asymmetric light conversion agent, comprising the following steps: Step S1, adding calcium carbonate to 1H-benzotriazole and an organic iodide in N,N-dimethylformamide, followed by heating, separation, dehydration, filtration, and isolation to obtain a first intermediate; Step S2, stirring the first intermediate with liquid bromine and hydrobromic acid, heating under reflux, extracting, separation, and isolation to obtain a second intermediate; Step S3, heating the second intermediate with thiopheneboronic acid, phenylboronic acid, potassium carbonate, and tetrakis(triphenylphosphine)palladium under a nitrogen atmosphere, cooling the reaction mixture to room temperature after completion, dehydration, filtration, and isolation to obtain the asymmetric light conversion agent.

[0010] In a third aspect, the present invention further provides a light-converting adhesive film comprising: a base film and an asymmetric structured light-converting agent; wherein the asymmetric structured light-converting agent comprises a combination of any one or more of the asymmetric structured light-converting agents described above; and the asymmetric structured light-converting agent is dispersed in the base film.

[0011] In a fourth aspect, the present invention further provides a method for preparing the aforementioned light-converting adhesive film, comprising: uniformly mixing a base resin, an asymmetric structure light-converting agent, and an auxiliary agent according to a raw material ratio; and casting a film to obtain the light-converting adhesive film.

[0012] In a fifth aspect, the present invention further provides a photovoltaic module comprising a light-converting adhesive film, wherein the light-converting adhesive film is the light-converting adhesive film as described above.

[0013] The beneficial effects of the present invention are as follows: the asymmetric structure light conversion agent, light conversion adhesive film and preparation method thereof of the present invention use benzotriazole as the matrix, and introduce asymmetric aromatic rings (heteroaryl and benzene ring) on ​​both sides of the benzene ring. On the one hand, heteroaryl groups such as thiophene aromatic rings have higher electron density and excellent carrier mobility than benzene rings; on the other hand, the asymmetric structure can enable the light conversion wavelength of the light conversion agent to have a wider control space, and can also further realize light conversion in different wavelength ranges by controlling the light-emitting units on both sides, thereby efficiently utilizing sunlight.

[0014] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.

[0015] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] FIG1 is a reaction formula for step S1 of a preferred embodiment of the asymmetric light conversion agent of the present invention;

[0018] FIG2 is a reaction formula for step S2 of a preferred embodiment of the asymmetric light conversion agent of the present invention;

[0019] FIG3 is a reaction formula of step S3 of a preferred embodiment of the asymmetric light conversion agent of the present invention.

[0020] FIG4 is a hydrogen spectrum of 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(thiophen-2-yl)-benzotriazole of the present invention;

[0021] FIG5 is a carbon spectrum of 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(thiophen-2-yl)-benzotriazole of the present invention;

[0022] FIG6 is a hydrogen spectrum of 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(benzothiophen-2-yl)-benzotriazole of the present invention;

[0023] FIG7 is a carbon spectrum of 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(benzothiophen-2-yl)-benzotriazole of the present invention;

[0024] FIG8 is a hydrogen spectrum of 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(5-formylthiophen-2-yl)-benzotriazole of the present invention;

[0025] FIG9 is a carbon spectrum of 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(5-formylthiophen-2-yl)-benzotriazole of the present invention. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] Benzotriazole compounds are increasingly being used as light-converting agents in light-converting films. However, existing benzotriazole compounds all have symmetrical structures, typically with benzene rings on both sides for light conversion. Thiophene, which also has an aromatic ring, becomes darker in color after being introduced into the benzotriazole system, making it difficult to use in packaging films.

[0028] The present invention provides an asymmetric structure light conversion agent, comprising: the light conversion agent is benzotriazole as a matrix, and asymmetric aromatic rings are introduced on both sides of the benzene ring; the asymmetric aromatic ring includes a heteroaryl group on one side and a benzene ring on the other side.

[0029] In this embodiment, specifically, the general structural formula of the light conversion agent is as follows:

[0030] in

[0031] R1 is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted carboxyl, substituted or unsubstituted carbonyl, substituted or unsubstituted amino, substituted or unsubstituted amide;

[0032] R2 is a substituted or unsubstituted heteroaryl group;

[0033] R3 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted amide group, a substituted or unsubstituted carboxyl group, or a substituted or unsubstituted carbonyl group.

[0034] The term "alkyl" refers to and includes both straight-chain and branched alkyl groups. Preferred alkyl groups are those containing from one to fifteen carbon atoms, more preferably from one to six carbon atoms; and include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, and the like. In addition, the alkyl group may be optionally substituted.

[0035] The term "alkenyl" refers to and includes both straight-chain and branched alkenyl groups. Alkenyl groups are essentially alkyl groups that include at least one carbon-carbon double bond in the alkyl chain. Preferred alkenyl groups contain from two to fifteen carbon atoms. More preferably, alkenyl groups contain from one to six carbon atoms. In addition, alkenyl groups may be optionally substituted.

[0036] The term "alkynyl" refers to and includes both straight-chain and branched alkynyl groups. An alkynyl group is essentially an alkyl group that includes at least one carbon-carbon triple bond in the alkyl chain. Preferred alkynyl groups are those containing two to fifteen carbon atoms. More preferred are those containing one to six carbon atoms. In addition, an alkynyl group may be optionally substituted.

[0037] The term "aryl" refers to and includes monocyclic aromatic hydrocarbon groups and polycyclic aromatic ring systems. Polycyclic rings can have two or more rings in which two carbon atoms are shared by two adjacent rings (the rings are "fused"), wherein at least one of the rings is an aromatic hydrocarbon group, for example, the other rings can be cycloalkyl, cycloalkenyl, aryl, heterocycle and / or heteroaryl. Preferred aryl groups are those containing six to thirty carbon atoms, preferably six to twenty carbon atoms, more preferably six to twelve carbon atoms. Especially preferred are aryl groups with six carbon atoms, ten carbon atoms or twelve carbon atoms. Suitable aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenanthren, fluorene, pyrene, Perylene and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene and naphthalene. In addition, the aryl group may be optionally substituted.

[0038] The term "heteroaryl" refers to and encompasses monocyclic aromatic groups and polycyclic aromatic ring systems that include at least one heteroatom. Heteroatoms include, but are not limited to, O, S, N, P, B, Si, and Se. In many cases, O, S, or N are preferred heteroatoms. Monocyclic heteroaromatic systems are preferably monocyclic rings having 5 or 6 ring atoms, and the rings may have from one to six heteroatoms. Heteropolycyclic ring systems may have two or more rings in which two atoms are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is a heteroaryl group, for example, the other rings may be cycloalkyl, cycloalkenyl, aryl, heterocycle, and / or heteroaryl groups. Heteropolycyclic aromatic ring systems may have from one to six heteroatoms in each ring of the polycyclic aromatic ring system. Preferred heteroaryl groups are those containing from three to thirty carbon atoms, preferably from three to twenty carbon atoms, and more preferably from three to twelve carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridyl indole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, , acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine and selenophenodipyridine, preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2-azaborane, 1,3-azaborane, 1,4-azaborane, borazine and aza analogs thereof. In addition, the heteroaryl group may be optionally substituted.

[0039] As used herein, the terms alkyl, alkenyl, alkynyl, aryl, and heteroaryl are independently unsubstituted or substituted with one or more typical substituents.

[0040] In some cases, preferred general substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, halogen, nitro, amino, aldehyde, carboxyl, cyano, isocyano.

[0041] In some cases, more preferred general substituents are selected from the group consisting of halogen, nitro, amino, aldehyde, carboxyl, cyano, isocyano, and combinations thereof.

[0042] In other cases, the most preferred general substituents are selected from the group consisting of halogen, nitro, amino, aldehyde, and combinations thereof.

[0043] The term "halogen" refers to: F, Cl, Br, I.

[0044] In this embodiment, specifically, when benzotriazole is used as the parent and asymmetric heteroaryl groups such as thiophene and benzene rings are introduced on both sides of the benzene ring, on the one hand, there are 6 π electrons on the thiophene aromatic ring, which has a higher electron density and a lower HOMO orbital energy level, which is conducive to hole transport and can produce blue-green light, and thiophene and its derivatives are very stable; on the other hand, the asymmetric structure can provide a wider range of control space for the light conversion wavelength of the light conversion agent. The thiophene group has a greater influence on the luminescent wavelength of the luminescent material. The luminescent color can be controlled by regulating the length of the thiophene conjugated chain, the type of substituent and the regularity of the polythiophene, and the luminescent wavelength control range can be between 400nm and 700nm; more importantly, the thiophene heterocycle is introduced only on one side while the benzene ring is retained on the other side to adjust the luminescent wavelength of the light conversion agent to shift to the blue light band.

[0045] In another aspect, the present invention further provides a method for preparing the asymmetric structure light conversion agent as described above, comprising the following steps: step S1, adding calcium carbonate to 1H-benzotriazole and an organic iodide in N,N-dimethylformamide, heating, separating, dehydrating, filtering, and isolating to obtain a first intermediate; step S2, stirring the first intermediate with liquid bromine and hydrobromic acid, heating under reflux, extracting, separating, and isolating to obtain a second intermediate; step S3, heating the second intermediate with thiopheneboronic acid, phenylboronic acid, potassium carbonate, and tetrakis(triphenylphosphine)palladium under a nitrogen environment, cooling the reaction to room temperature after completion, dehydrating, filtering, and isolating to obtain the asymmetric structure light conversion agent.

[0046] In this embodiment, specifically, the organic iodide structural formula is:

[0047] In this embodiment, specifically, the structural formula of the first intermediate is:

[0048] In this embodiment, specifically, the structural formula of the second intermediate is:

[0049] In this embodiment, specifically, the synthesis route reaction formula of the asymmetric structure light conversion agent is:

[0050] In a third aspect, the present invention further provides a light-converting adhesive film comprising: a base film and an asymmetric structured light-converting agent; wherein the asymmetric structured light-converting agent comprises a combination of any one or more of the asymmetric structured light-converting agents described above; and the asymmetric structured light-converting agent is dispersed in the base film.

[0051] In this embodiment, specifically, the raw materials are mixed in proportions by mass: 100 parts of base resin; 0.2 to 1.5 parts of cross-linking agent; 0.1 to 3 parts of auxiliary cross-linking agent; 0.1 to 1 part of light stabilizer; 0.01 to 0.3 parts of antioxidant; 0.2 to 1 part of coupling agent; and 0.01 to 10 parts of asymmetric structure light conversion agent.

[0052] In this embodiment, specifically, the base film includes any one or more combinations of EVA, PMMA, POE, and PVB.

[0053] In this embodiment, specifically, the cross-linking agent includes a combination of one or more of tert-butyl peroxy-2-ethylhexyl carbonate, tert-amyl peroxy-2-ethylhexyl carbonate, tert-butyl peroxy-3,5,5-trimethylhexanoate, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0054] In this embodiment, specifically, the auxiliary cross-linking agent includes a combination of one or more of triallyl isocyanurate TAIC and trimethylolpropane triacrylate TMPTA.

[0055] In this embodiment, specifically, the light stabilizer includes a combination of one or more of light stabilizer 622, light stabilizer 770, light stabilizer 944, light stabilizer 783, light stabilizer 123, light stabilizer 765, light stabilizer 2908, light stabilizer 531, light stabilizer 327, and light stabilizer 328.

[0056] In this embodiment, specifically, the antioxidant includes one or more combinations of aromatic amines, hindered phenols, and auxiliary antioxidants.

[0057] In this embodiment, specifically, the coupling agent includes one or more of KH-550, KH-560, KH-570, A-174, KBM-503, Z-6030, KH-792, A-1120, Z-6020, KBM-603, KH-791, A-151, and A-171, or a combination thereof.

[0058] In a fourth aspect, the present invention further provides a method for preparing the aforementioned light-converting adhesive film, comprising: uniformly mixing a base resin, an asymmetric structure light-converting agent, and an auxiliary agent according to a raw material ratio; and casting a film to obtain the light-converting adhesive film.

[0059] In a fifth aspect, the present invention further provides a photovoltaic module comprising a light-converting adhesive film, wherein the light-converting adhesive film is the light-converting adhesive film as described above.

[0060] Example 1

[0061] Step S1, as shown in Figure 1, takes 1H-benzotriazole (50mmol, 6.078g, w = 98%), potassium carbonate (150mmol, 20.924g, w = 99%) and isobutane iodide (60mmol, 11.041g, w = 97%), adds them to a round-bottom flask, adds N, N-dimethylformamide 100mL as solvent, stirs and heats at 80°C for 5h, washes with saturated ammonium chloride solution several times to remove N, N-dimethylformamide, extracts with ethyl acetate, retains the upper liquid, adds anhydrous sodium sulfate to remove water, filters, and separates through a column to obtain 4.100g of 2-isobutylbenzotriazole, with an isolation yield of 46.79%.

[0062] Step S2, as shown in Figure 2, takes 2-isobutylbenzotriazole (23.394mmol, 4.100g), liquid bromine (70.194mmol, 11.217g, 3.600mL), and hydrobromic acid (206.428mmol, 34.825g, w=48%, 23.4mL), and is added to a round-bottom flask in sequence. The mixture is stirred and heated under reflux at 130°C for 24h. After the reaction is completed, the excess liquid bromine and hydrobromic acid are removed with cold saturated potassium hydroxide solution, and the liquid is extracted with dichloromethane. Anhydrous sodium sulfate is added to remove water, and the mixture is separated by column separation to obtain 6.658g of the product with an isolation yield of 85.44%.

[0063] In step S3, as shown in FIG3 , 2-thiopheneboronic acid (1 mmol, 130.56 mg, w = 98%), tert-butylphenylboronic acid (1 mmol, 181.67 mg, w = 98%), 4,7-dibromo-2-isobutylbenzotriazole (1 mmol, 333.03 mg), potassium carbonate (5.12 mmol, 714.78 mg, w = 99%), and tetrakis(triphenylphosphine)palladium (0.11 mmol, 128.39 mg, w = 99%) were taken. 2-Thiopheneboronic acid, phenylboronic acid, and potassium carbonate were added to a three-necked flask. The air was evacuated and nitrogen was filled. Toluene (2.56 mL), n-butanol (5.12 mL), and water (0.76 mL) were mixed with 4,7-dibromo-2-isobutylbenzotriazole and transferred to a nitrogen-filled three-necked flask using a syringe. The solution was heated at 100°C with stirring for 1 hour to dissolve and remove dissolved oxygen from the solvent. After 1 hour, heating was stopped and the temperature was lowered to below 50°C. Tetrakis(triphenylphosphine)palladium was added under a nitrogen atmosphere, and the mixture was sealed. The temperature was raised to 100°C and continued to stir and heat for 8 hours. After the reaction was complete, the solution was cooled to room temperature, anhydrous sulfuric acid was added to remove water, and the solution was filtered and separated by column chromatography to obtain a solid, which is the asymmetric light conversion agent.

[0064] Example 2

[0065] In this embodiment, specifically, the pre-reaction step in Example 1 was adjusted to prepare an asymmetric thiophene structure.

[0066] Take 2-isobutylbenzotriazole (17.623mmol, 3.088g), hydrobromic acid (127.208mmol, 10.292g, w = 48%, 6.9mL), and liquid bromine (19.358mmol, 3.098g, 0.993mL) and add them to a round-bottom flask in sequence. Stir and heat under reflux at 130°C for 18h. After the reaction is completed, remove excess liquid bromine and hydrobromic acid with cold saturated potassium hydroxide solution, extract with dichloromethane, add anhydrous sodium sulfate to remove water, and separate by column separation to obtain 2.225g of product 4-bromo-2-isobutyl-benzotriazole (light yellow transparent viscous liquid) with an isolation yield of 49.58%.

[0067] The reaction formula is:

[0068] Take 4-bromo-2-isobutyl-benzotriazole (7.635mmol, 1.940g), 4-tert-butylphenylboronic acid (11.453mmol, 2.080g, w=98%), potassium carbonate (39.091mmol, 5.402g, w=99%), and tetrakistriphenylphosphine palladium (0.11mmol, 970.58mg, w=99%). First, p-tert-butylphenylboronic acid and potassium carbonate were added to a three-necked flask, the air was evacuated and nitrogen was filled. Toluene (19.55 mL), n-butanol (39.1 mL), and water (5.8 mL) were mixed uniformly with 4-bromo-2-isobutyl-benzotriazole and transferred to a nitrogen-filled three-necked flask using a syringe. After stirring at 100°C for 1 hour, heating was stopped and the flask was cooled to below 50°C. Under nitrogen, the three-necked flask was opened to remove oxygen from the toluene. Tetrakis(triphenylphosphine)palladium was quickly added under a nitrogen atmosphere and sealed. The temperature was raised to 100°C and stirring and heating were continued for 12 hours. After completion of the reaction, the flask was cooled to room temperature, anhydrous sodium sulfate was added to remove water, and the mixture was filtered and separated by column chromatography to obtain 1.186 g of the product 4-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole (a slightly yellowish white transparent viscous liquid) with an isolated yield of 50.5%.

[0069] The reaction formula is:

[0070] 1.186 g (3.858 mmol, 1.186 g) of 4-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole, hydrobromic acid (25.876 mmol, 4.361 g, w = 48%, 2.9 mL), and liquid bromine (3.858 mmol, 616.51 mg, 0.198 mL) were added to a round-bottom flask in sequence, and the mixture was stirred and heated under reflux at 130 ° C. for 18 h. After the reaction was completed, the excess liquid bromine and hydrobromic acid were removed with cold saturated potassium hydroxide solution. The liquid was extracted with dichloromethane, and anhydrous sodium sulfate was added to remove water. The mixture was filtered and separated by column chromatography to obtain 1.175 g (white solid) of the product 4-bromo-7-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole with an isolation yield of 78.85%.

[0071] The reaction formula is:

[0072] Take 4-bromo-7-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole (0.579mmol, 223.9mg), 2-thiopheneboronic acid (0.8685mmol, 111.12mg), potassium carbonate (2.964mmol, 409.65mg, w=99%), and tetrakistriphenylphosphine palladium (0.0636mmol, 73.60mg, w=99%).

[0073] 4-Bromo-7-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole, 2-thiopheneboronic acid, potassium carbonate and tetrakis(triphenylphosphine)palladium were added to a reaction tube, the air was evacuated and nitrogen was introduced, 1.48 mL of toluene, 2.96 mL of n-butanol and 0.44 mL of water were added to a beaker and mixed, and injected into the reaction tube with a syringe. The reaction tube was sealed and reacted at 100° C. for 12 h. Anhydrous sodium sulfate was added to remove water, filtered, and the solvent was evaporated by rotary evaporation. After column separation, 194.19 mg of the product 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(thiophen-2-yl)-benzotriazole (pale yellowish green solid) was obtained (absorption 310 nm, emission 436 nm) with an isolation yield of 86.1%.

[0074] The reaction formula is:

[0075] As shown in Figure 4, the hydrogen spectrum of the obtained product is 1H NMR(300MHz,Chloroform-d)δ8.01(d,J=3.4Hz,1H),7.90(d,J=8.2Hz,2H),7.57(d,J=7.5Hz,1H),7.43(d,J=7.7Hz,3H),7.25( d,J=5.0Hz,1H),7.07(t,J=4.3Hz,1H),4.49(d,J=7.3Hz,2H),2.50(dp,J=13.6,6.8Hz,1H),1.28(s,9H),0.91(d,J=6.7Hz,6H).

[0076] As shown in Figure 5, the carbon spectrum of the obtained product is 13 C NMR(75MHz,Chloroform-d)δ150.97, 143.36,142.41,140.19,130.01,128.22,128.12,126.97,125.74,125.43,124.22,123.56,123.02,63.84,34.72,31.43,29.93,20.10.

[0077] Example 3

[0078] In this embodiment, specifically, a benzothiophene asymmetric structure is prepared.

[0079] Take 4-bromo-7-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole (0.700mmol, 270.44mg), 2-benzothiopheneboronic acid (1.05mmol, 190.73mg, w=98%), potassium carbonate (3.584mmol, 495.82mg, w=99%), and tetrakistriphenylphosphine palladium (0.077mmol, 88.98mg, w=99%).

[0080] 4-Bromo-7-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole, 2-benzothiopheneboric acid, potassium carbonate and tetrakis(triphenylphosphine)palladium were added to a sealed reaction tube, the air was evacuated and nitrogen was introduced, 1.8 mL of toluene, 3.6 mL of n-butanol and 0.53 mL of water were added to a beaker and mixed, and injected into the reaction tube with a syringe. The sealed reaction tube was reacted at 100° C. for 12 h, anhydrous sodium sulfate was added to remove water, the mixture was filtered, the solvent was evaporated by rotary evaporation and then separated by column to obtain 263.2 mg of the product 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(benzothiophen-2-yl)-benzotriazole (pale yellowish green solid) (absorption 329 nm emission 444 nm) with an isolated yield of 85.52%.

[0081] The reaction formula is:

[0082] As shown in Figure 6, the hydrogen spectrum of the obtained product is 1 H NMR(400MHz,Chloroform-d)δ8.38(s,1H),7.92(d,J=8.4Hz,2H),7.78(t,J=7.2Hz,2H),7.66(d,J=7.5Hz,1H),7.47(t,J =7.9Hz,3H),7.31–7.22(m,2H),4.56(d,J=7.4Hz,2H),2.57(dp,J=13.8,6.9Hz,1H),1.30(s,9H),0.96(d,J=6.7Hz,6H).

[0083] As shown in Figure 7, the carbon spectrum of the obtained product is 13 C NMR(101MHz,Chloroform-d)δ151.26, 143.40,142.62,141.02,140.09,139.37,134.36,131.06,128.35,125.85,124.75,124. 56,124.48,124.24,124.23,124.14,123.44,122.23,63.95,34.81,31.47,30.05,20.16.

[0084] Example 4

[0085] In this embodiment, specifically, a 5-formylthiophene asymmetric structure is prepared.

[0086] Take 4-bromo-7-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole (0.200mmol, 77.27mg), 5-formyl-2-thiopheneboronic acid (0.300mmol, 47.74mg, w=98%), potassium carbonate (1.024mmol, 141.53mg, w=99%), and tetrakistriphenylphosphine palladium (0.022mmol, 25.42mg, w=99%).

[0087] 4-Bromo-7-(4-(tert-butyl)phenyl)-2-isobutyl-benzotriazole, 5-formyl-2-thiopheneboronic acid, potassium carbonate and tetrakis(triphenylphosphine)palladium were added to a sealed reaction tube, the air was evacuated and nitrogen was introduced, 0.52 mL of toluene, 1.04 mL of n-butanol and 0.15 mL of water were added to a beaker and mixed, and injected into the reaction tube with a syringe. The sealed reaction tube was reacted at 100° C. for 12 h, anhydrous sodium sulfate was added to remove water, filtered, the solvent was evaporated by rotary evaporation and then separated by column to obtain 21.1 mg of the product 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(5-formylthiophen-2-yl)-benzotriazole (yellow solid) (absorption 453 nm emission 484 nm) with an isolation yield of 25.27%.

[0088] The reaction formula is:

[0089] As shown in Figure 8, the hydrogen spectrum of the obtained product is 1 H NMR(400MHz,Chloroform-d)δ9.96(s,1H),8.18(d,J=4.0Hz,1H),8.02(d,J=8.5Hz,2H),7.88–7.79(m,2H),7.59 (dd,J=17.7,8.0Hz,3H),4.64(d,J=7.3Hz,2H),2.63(dp,J=13.8,6.9Hz,1H),1.39(s,9H),1.04(d,J=6.7Hz,6H).

[0090] As shown in Figure 9, the carbon spectrum of the obtained product is 13 C NMR(101MHz,Chloroform-d)δ151.74,150.04,143.38,142.61,137.48,134.03,132.60 ,128.45,127.47,125.94,124.68,124.12,122.08,64.10,34.88,31.46,30.05,20.15.

[0091] The asymmetric structure light conversion agents prepared in Examples 1, 3, and 4 were further used to prepare light conversion adhesive films at different mass ratios. The test properties are shown in Table 1:

[0092] Test method:

[0093] Light conversion efficiency: Horiba spectrometer FL-3, absolute quantum efficiency test was performed using an integrating sphere at room temperature.

[0094] Yellowing index: The yellowing index (ΔYI) of the pre-pressed components before and after the aging test was measured in accordance with the national standard GB 2409 "Test method for yellowness index of plastics".

[0095] Table 1

[0096] Among them, Examples 1-1, 1-2, and 1-3 are the performance data of the film group of the 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(thiophene-2-yl)-benzotriazole product of Example 1 at different light conversion agent addition amounts; Examples 3-1, 3-2, and 3-3 are the performance data of the film group of the 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(benzothiophene-2-yl)-benzotriazole product of Example 3 at different light conversion agent addition amounts; Examples 4-1, 4-2, and 4-3 are the performance data of the film group of the 4-(4-(tert-butyl)phenyl)-2-isobutyl-7-(5-formylthiophene-2-yl)-benzotriazole product of Example 4 at different light conversion agent addition amounts.

[0097] In this embodiment, specifically, the base EVA resin is preferably DuPont 53071 of the United States, the cross-linking agent is preferably 0.3 parts of tert-butyl peroxide 2-ethylhexyl carbonate, the auxiliary cross-linking agent is preferably 0.2 parts of triallyl isocyanurate, the light stabilizer is preferably 0.1 parts of light stabilizer 770, the antioxidant is preferably 0.1 parts of hindered phenol antioxidant 1010, and the silane coupling agent is preferably 0.2 parts of KH-570, and the remainder is the base EVA resin.

[0098] In summary, the asymmetric structure of the light-converting agent, light-converting adhesive film, and preparation method thereof of the present invention uses benzotriazole as the parent body, with asymmetric aromatic rings (heteroaryl and benzene rings) introduced on both sides of the benzene ring. On the one hand, heteroaryl groups, such as thiophene aromatic rings, have higher electron density and excellent carrier mobility than benzene rings. On the other hand, the asymmetric structure allows the light-converting agent to have a wider range of controllable wavelengths. At the same time, it can also further achieve light conversion in different wavelength ranges by controlling the light-emitting units on both sides, thereby efficiently utilizing sunlight.

[0099] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. An asymmetric structure light conversion agent, characterized in that: The general structural formula of the light conversion agent is as follows: in R1 is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted carbonyl, substituted or unsubstituted amide; R2 is a substituted or unsubstituted heteroaryl group; R3 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted amide group, or a substituted or unsubstituted carboxyl group; The heteroaryl group is thiophene or benzothiophene; The optional substituent is selected from the group consisting of: alkyl, halogen, nitro, amino, aldehyde, carboxyl, cyano, isocyano, and the number of the substituent is: 1, 2, 3 or 4.

2. A method for preparing the asymmetric structure light conversion agent according to claim 1, characterized in that: The steps include: Step S1, adding calcium carbonate to 1H-benzotriazole and organic iodide I-R3 in N,N-dimethylformamide, heating, liquid separation, dehydration, filtering, and separation to obtain a first intermediate, the structural formula of the first intermediate is: Step S2, stirring and heating the first intermediate with liquid bromine and hydrobromic acid to reflux, extracting, separating, The second intermediate is separated and obtained, and the structural formula of the second intermediate is: Step S3, reacting the second intermediate with R2-B(OH)2, Potassium carbonate and tetrakis(triphenylphosphine)palladium are heated under a nitrogen environment, and after the reaction is completed, the mixture is cooled to room temperature, and water is removed, filtered, and separated to obtain an asymmetric structure light conversion agent; R1, R2, and R3 in the above structure are the same as defined in claim 1.

3. The asymmetric structure light conversion agent according to claim 1 or the asymmetric structure light conversion agent prepared by the preparation method according to claim 2, characterized in that: Selected from the following compounds:

4. A light-converting adhesive film, characterized in that: include: Basement membrane and asymmetric structure light conversion agent; in The asymmetric structure light conversion agent comprises any one or more combinations of the asymmetric structure light conversion agents as described in claims 1 to 3; and The asymmetric structure light conversion agent is dispersed in the base film.

5. The light-converting adhesive film according to claim 4, characterized in that: The raw materials include:

6. The light-converting adhesive film according to claim 4, characterized in that: The base film is selected from any one or more combinations of EVA, PMMA, POE and PVB.

7. A method for preparing a light-converting adhesive film according to any one of claims 4 to 6, characterized in that: include: Mix the base resin, asymmetric structure light conversion agent and auxiliary agent evenly according to the raw material ratio; The light-converting adhesive film is obtained by film casting.

8. A photovoltaic module, comprising a light-converting adhesive film, characterized in that: The light-converting adhesive film is the light-converting adhesive film according to any one of claims 4 to 6.

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