Polyalkyl fluorene organic blue fluorescent material containing pyrazoline ring and application of polyalkyl fluorene organic blue fluorescent material in preparation of photovoltaic adhesive film

Abstract

The invention discloses a polyalkyl fluorene organic blue fluorescent material containing a pyrazoline ring and application of the polyalkyl fluorene organic blue fluorescent material in preparation of a photovoltaic adhesive film. The structural general formula of the polyalkyl fluorene organic blue fluorescent material containing the pyrazoline ring is as follows: # imgabs0 #, wherein R is selected from one of bromine, fluorine, chlorine, nitro, cyano, hydrogen or C1-12 alkyl. The organic blue fluorescent material of the pyrazoline ring-containing polyalkyl fluorene structure is added into a photovoltaic adhesive film as a light conversion agent to serve as a light conversion material, can absorb ultraviolet light to protect a solar cell, and releases visible light to be absorbed by the solar cell, so that the efficiency of the solar cell is improved. The series of light conversion materials are simple in synthesis process, stable in yield and suitable for industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of light conversion materials, and particularly relates to a polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring and its application in the preparation of a photovoltaic film. Background Art

[0002] The sunlight wavelength range that can be utilized by solar cells is between 300 nm and 1100 nm. However, ultraviolet light (220 - 400 nm) is harmful to solar cells, which will accelerate the aging of solar cells, reduce their conversion efficiency, and is particularly more destructive to the new generation of heterojunction and perovskite cells, greatly limiting the application and popularization of heterojunction and perovskite cells. In order to improve the performance and lifespan of solar cell modules, it is necessary to use a photovoltaic film to encapsulate the cell wafers.

[0003] Photovoltaic resins have characteristics such as high light transmittance, ultraviolet resistance, and resistance to hygrothermal yellowing, and are the most widely used photovoltaic film materials in commercial scenarios of solar cells. Their performance directly determines the product quality and service life of photovoltaic modules. Although photovoltaic resins have the characteristic of high light transmittance, due to the blocking effect of the resin film on ultraviolet light, the ultraviolet light that accounts for 5% of the energy in sunlight cannot be utilized by the cell wafers and then undergo photoelectric conversion, resulting in a low photoelectric conversion efficiency. Introducing a light conversion agent into the film can not only absorb ultraviolet light in the range of 220 - 400 nm and block ultraviolet light, but also convert ultraviolet light into visible light such as red, green, and blue, thereby ensuring that the lifespan of the solar cell panel can reach more than 20 years, and at the same time can make up for the problem of reduced light conversion efficiency caused by the blocking of ultraviolet light.

[0004] Most of the existing light conversion materials are small molecule organic fluorescent materials, which have the problem of poor stability. Therefore, there is an urgent need to develop a light conversion material with high stability and high quantum efficiency. This material can absorb ultraviolet light to protect solar cells, emit light with a wavelength greater than 400 nm for use by solar cells, and can improve the light conversion efficiency of solar cells. Summary of the Invention

[0005] Based on the above problems existing in the prior art, the present invention provides a polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring and its application in the preparation of a photovoltaic film. The polymer of the present invention has a high quantum efficiency as a light conversion material. Applying it to a photovoltaic film can improve the light conversion efficiency of solar cells and accelerate the development of the photovoltaic industry.

[0006] The polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring of the present invention has the following general structural formula:

[0007]

[0008] wherein R is selected from one of bromine, fluorine, chlorine, nitro, cyano, hydrogen or C 1-12 alkyl.

[0009] The preparation method of the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring in the present invention comprises the following steps:

[0010] Step 1: Add a mixed solution of anhydrous potassium carbonate and N,N-dimethylformamide to the mixture of compound A and 5-bromosalicylaldehyde, heat and stir under nitrogen protection, filter after the reaction is completed, and obtain intermediate 1 after purification by column chromatography;

[0011] Step 2: Add ethanol and sodium hydroxide solution to the mixture of 4-bromoacetophenone and intermediate 1, react at room temperature, filter after the reaction is completed, wash the crude product, and obtain intermediate 2 after recrystallization;

[0012] Step 3: Mix 2-hydrazinobenzothiazole, intermediate 2 and ethylene glycol monoethyl ether, heat to reflux reaction under nitrogen protection, filter after the reaction is completed, obtain the crude product, and obtain intermediate 3 after recrystallization;

[0013] Step 4: Mix 9,9-dihexylfluorene-2,7-bis(trioxymethylene)borate, intermediate 3, tetrakis(triphenylphosphine)palladium, potassium carbonate solution and toluene, heat to reflux reaction under nitrogen protection, pour into methanol aqueous solution after the reaction is completed to generate a precipitate, filter and wash with methanol and pure water in sequence to obtain the crude product, and carry out extraction and purification in a Soxhlet extractor to obtain the target product.

[0014] The synthesis route is as follows:

[0015]

[0016] wherein R is selected from one of bromine, fluorine, chlorine, nitro, cyano, hydrogen or C 1-12 alkyl.

[0017] In Step 1, the molar ratio of compound A to 5-bromosalicylaldehyde is 1:1; the volume ratio of the mixed solution of anhydrous potassium carbonate and N,N-dimethylformamide is 1:5-10.

[0018] In Step 1, the heating temperature is 90-110 °C and the reaction time is 10-15 h.

[0019] In Step 1, the eluent used for purification by column chromatography is CH2Cl2.

[0020] In Step 2, the molar ratio of 4-bromoacetophenone to intermediate 1 is 1:1; the volume ratio of sodium hydroxide solution to ethanol is 1:8-12, and the concentration of the sodium hydroxide solution is 30 wt%.

[0021] In Step 2, the reaction time is 2-6 h.

[0022] In Step 2, the solvent used for recrystallization is ethanol.

[0023] In Step 3, the molar ratio of Intermediate 2 to 2-hydrazinobenzothiazole is 1:1; the ratio of the total volume of Intermediate 2 and 2-hydrazinobenzothiazole to the volume of ethylene glycol monoethyl ether is 1:2 - 5.

[0024] In Step 3, the reaction temperature is 90°C - 130°C and the reaction time is 2 - 4 h.

[0025] In Step 3, the solvent used for recrystallization is ethanol.

[0026] In Step 4, the molar ratio of 9,9-dihexylfluorene-2,7-di(trioxymethylene)borate, Intermediate 3 to tetrakis(triphenylphosphine)palladium is 100:100:1; the volume ratio of potassium carbonate solution to toluene is 1:1, where the concentration of the potassium carbonate solution is 2 M.

[0027] In Step 4, the reaction temperature is 75°C - 95°C and the reaction time is 40 - 50 h.

[0028] In Step 4, the solvent used for Soxhlet extraction is acetone and the extraction time is 20 - 30 h.

[0029] The application of the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring in the preparation of a photovoltaic adhesive film.

[0030] Specifically, in the process of preparing the photovoltaic adhesive film, the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring is used as a light conversion material and added to the photovoltaic adhesive film system, and then applied to a photovoltaic device or a solar cell.

[0031] The specific steps are as follows:

[0032] Mix the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring with EVA or POE particles, add them to a twin-screw extruder, heat and melt them evenly, extrude into long strips, cool and form them with water, and granulate them through a granulator. The obtained material is cast into a film through a casting machine.

[0033] The added mass of the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring is 0.01% - 0.15% of the mass of the EVA or POE particles.

[0034] The polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring in the present invention has a high quantum yield and good stability, and is an excellent blue light material in the field of photoluminescence. When it is added to a photovoltaic film as a light conversion agent, its function is to absorb ultraviolet light to protect the solar cell, and at the same time release visible light for the solar cell to absorb, thereby improving its efficiency. The synthesis process of this series of light conversion materials is simple, and the yield is stable, which is suitable for industrial production.

[0035] The preparation process conditions of the polyalkylfluorene organic blue fluorescent material with a pyrazoline ring provided by the present invention are mild, the operation is simple, the raw materials are easy to obtain, and the practicability is strong. It has very good application prospects in the fields of fluorescence detection, biological imaging, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is the ultraviolet and fluorescence performance diagram of the light conversion material.

[0037] Figure 2 It is the TGA curve diagram of the light conversion material.

[0038] Figure 3 It is the quantum efficiency diagram of the light conversion material.

[0039] Figure 4 It is the molecular weight distribution diagram of the light conversion material in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0040] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention.

[0041] The present invention will be further described below in conjunction with specific embodiments, but does not limit the content of the present invention.

[0042] Preparation Example:

[0043]

[0044] The preparation method of the light conversion material in this example includes the following steps:

[0045] 1. Synthesize Intermediate 1

[0046] A mixture of 1-bromododecane and 5-bromosalicylaldehyde was fed in a 1:1 ratio for reaction. Then, a mixed solution of anhydrous potassium carbonate and N,N-dimethylformamide with a volume ratio of 1:6 was added. Under nitrogen protection, the mixture was heated to 90 - 110 °C and stirred. After reacting for 12 h, it was filtered. The crude product was purified by column chromatography (eluent: CH2Cl2) to obtain a light yellowish-brown oily liquid, which was Intermediate 1;

[0047] 2. Synthesis of Intermediate 2

[0048] A mixture of 4-bromoacetophenone and Intermediate 1 was fed in a 1:1 ratio for reaction. Then, a 30% sodium hydroxide solution and ethanol with a volume ratio of 1:10 were added. The reaction temperature was at room temperature, and it was vigorously stirred for 4 h for sufficient reaction. After the reaction, it was filtered. The filter cake was washed successively with water and methanol. The crude product was recrystallized with ethanol to obtain a light yellow solid, which was Intermediate 2;

[0049] 3. Synthesis of Intermediate 3

[0050] 2-Hydrazinobenzothiazole and Intermediate 2 were fed in a 1:1 ratio and added to ethylene glycol monoethyl ether with a volume ratio of 1:3. Under nitrogen protection, it was heated to 90 °C - 130 °C and reacted for 3 h. After the reaction, it was cooled to room temperature and filtered. The crude product was recrystallized with ethanol to obtain a light yellow solid powder, which was Intermediate 3;

[0051] 4. Synthesis of the target product

[0052] 9,9-Dihexylfluorene-2,7-di(trioxymethylene)borate, Intermediate 3, and tetrakis(triphenylphosphine)palladium were fed in a ratio of 100:100:1. Then, a 2M potassium carbonate solution and toluene mixed solution with a volume ratio of 1:1 were added. Under nitrogen protection, it was heated to 75 - 95 °C and refluxed. After the reaction, it was poured into a methanol aqueous solution to form a precipitate. After filtration, it was washed successively with methanol and pure water to obtain the crude product, which was purified by Soxhlet extraction with acetone for 24 h to obtain the target product.

[0053] Application Example 1: Preparation method of a photovoltaic adhesive film of a polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring

[0054] The synthesized light conversion material 1 and EVA particles were mixed, and the addition amount of light conversion material 1 was 0.1% by mass ratio and added to a twin-screw extruder. Through heating and melting, they were mixed evenly, extruded into long strips, cooled and formed by a cold water bath, and pelletized by a pelletizer. Then, the mixed material was made into an adhesive film by a casting machine.

[0055] Experimental method: The power of the module was detected according to the method in IEC61215. The specific test data are shown in the following table:

[0056]

[0057] In summary, the light conversion material in the present invention can well meet the requirement of absorbing ultraviolet light to protect the solar cell, and at the same time emit light with a wavelength greater than 400 nm for the use of the solar cell, which can improve the light conversion efficiency of the solar cell to a certain extent.

Claims

1. A polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring, characterized in that Its structural general formula is as follows: ； wherein R is selected from bromine, fluorine, chlorine, nitro, cyano, hydrogen or C 1-12 alkyl group.

2. The preparation method of the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring as described in claim 1, characterized in that It includes the following steps: Step 1: Add a mixed solution of anhydrous potassium carbonate and N,N-dimethylformamide to the mixture of compound A and 5-bromosalicylaldehyde, heat and stir under nitrogen protection. After the reaction is completed, filter, and obtain intermediate 1 after purification by column chromatography; Step 2: Add ethanol and sodium hydroxide solution to the mixture of 4-bromoacetophenone and intermediate 1, react at room temperature. After the reaction is completed, filter, wash the crude product, and obtain intermediate 2 after recrystallization; Step 3: Mix 2-hydrazinobenzothiazole, intermediate 2 and ethylene glycol monoethyl ether, heat to reflux under nitrogen protection for reaction. After the reaction is completed, filter to obtain the crude product, and obtain intermediate 3 after recrystallization; Step 4: Mix 9,9-dihexylfluorene-2,7-di(trioxymethylene)borate, intermediate 3, tetrakis(triphenylphosphine)palladium, potassium carbonate solution and toluene, heat to reflux under nitrogen protection for reaction. After the reaction is completed, pour it into a methanol-aqueous solution to produce a precipitate. After filtration, wash with methanol and pure water in sequence to obtain the crude product, and carry out extraction and purification in a Soxhlet extractor to obtain the target product; The synthesis route is as follows: ； wherein R is selected from bromine, fluorine, chlorine, nitro, cyano, hydrogen or C 1-12 alkyl group.

3. According to the preparation method described in claim 2, it is characterized in that: In step 1, the molar ratio of compound A to 5-bromosalicylaldehyde is 1:

1.

4. According to the preparation method described in claim 2, it is characterized in that: In step 1, the eluent used for column chromatography purification is CH2Cl2.

5. According to the preparation method described in claim 2, it is characterized in that: In step 2, the molar ratio of 4-bromoacetophenone to intermediate 1 is 1:

1.

6. According to the preparation method described in claim 2, it is characterized in that: In step 2, the solvent used for recrystallization is ethanol.

7. According to the preparation method described in claim 2, it is characterized in that: In step 3, the molar ratio of intermediate 2 to 2-hydrazinobenzothiazole is 1:

1.

8. According to the preparation method described in claim 2, it is characterized in that: In step 4, the molar ratio of 9,9-dihexylfluorene-2,7-di(trioxymethylene)borate, intermediate 3 and tetrakis(triphenylphosphine)palladium is 100:100:

1.

9. Use of the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring described in claim 1 in the preparation of a photovoltaic adhesive film.

10. According to the use described in claim 9, it is characterized in that: In the process of preparing the photovoltaic adhesive film, the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring is used as a light conversion material and added to the photovoltaic adhesive film system for preparing a photovoltaic device or a solar cell; The addition amount of the polyalkylfluorene organic blue fluorescent material containing a pyrazoline ring is 0.01%-0.15%.

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