High-weather-resistance photovoltaic adhesive film as well as preparation method and application thereof

Abstract

The invention discloses a high-weather-resistance photovoltaic adhesive film as well as a preparation method and application thereof. The preparation method comprises the following steps: catalyzing ethylene polymerization reaction by adopting an alpha-diimine nickel metal catalyst and a cocatalyst to generate a vinyl polyolefin elastomer; the vinyl polyolefin elastomer, POE, an antioxidant and a cross-linking agent are mixed in proportion, melt mixing, extrusion and film casting are carried out, and the vinyl polyolefin elastomer photovoltaic adhesive film is obtained; the cocatalyst is an aluminum-based catalyst. The vinyl elastomer is generated by catalyzing ethylene polymerization reaction by using an alpha-diimine nickel metal catalyst and a main catalyst, the catalyst has high thermal stability and activity in the catalytic reaction, and ethylene can be catalytically polymerized to generate the vinyl polyolefin elastomer with excellent performance indexes without the participation of alpha-olefin.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic adhesive films, and in particular relates to a highly weather-resistant photovoltaic adhesive film and a preparation method and application thereof. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Solar energy is a renewable and clean energy source, and distributed solar panels have become its main use. Photovoltaic film is the packaging material of solar cell modules, which plays the role of bonding, supporting, buffering and protecting the cells. It is one of the key components that affect the service life and power generation efficiency of photovoltaic modules. Improving weather resistance is of great significance to the development of the photovoltaic industry and reducing carbon emissions.

[0004] The current mainstream photovoltaic film uses ethylene-vinyl acetate copolymer (EVA) material, but EVA molecules are easily decomposed by water molecules to produce acidic groups, which corrode the components. Polyethylene octene copolymer (POE) does not contain polar groups in its molecular structure, and is not easy to produce PID effect under the action of water vapor, which can enhance the resistance of photovoltaic components to environmental erosion; the side groups in the molecular structure can play a connecting and buffering role, making the film have better impact resistance. However, the production process of POE is complicated and the cost is high. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a highly weather-resistant photovoltaic adhesive film and a preparation method and application thereof, mainly to solve the problems of poor weather resistance and high cost of the current photovoltaic adhesive film.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a highly weather-resistant photovoltaic adhesive film, comprising the following steps:

[0008] An α-diimide nickel metal catalyst and a co-catalyst are used to catalyze the polymerization of ethylene to produce a vinyl polyolefin elastomer; the vinyl polyolefin elastomer, POE, an antioxidant and a cross-linking agent are mixed in proportion, melt-mixed, extruded and cast into a film to obtain a vinyl polyolefin elastomer photovoltaic film;

[0009] The structural formula of the α-diimine nickel metal catalyst is:

[0010]

[0011] Among them, R 2 , R 7 , R 9 , R12 independently selected from hydrogen, C 1 ~C 6 Alkyl, halogen or halogenated C 1 ~C 6 One of the alkyl groups;

[0012] R 1 , R 8 independently selected from hydrogen, C 2 ~C 6 Alkyl, halogen or halogenated C 2 ~C 6 Alkyl, nitro, C 2 ~C 6 One of alkoxy and trifluoromethyl;

[0013] R 3 , R 6 , R 10 , R 11 independently selected from hydrogen, C 2 ~C 6 Alkyl, halogen or halogenated C 2 ~C 6 One of alkyl, phenyl and diphenylmethyl;

[0014] R 4 , R 5 independently selected from hydrogen, C 2 ~C 6 Alkyl, C 2 ~C 6 Halogenated alkyl, phenyl, C 6 ~C 30 Substituted phenyl;

[0015] X is selected from halogen, C 2 ~C 6 Alkanes, C 2 ~C 6 One of olefin, allyl or benzyl;

[0016] The co-catalyst is an aluminum-based catalyst.

[0017] α-Diimine nickel metal catalysts have unique chain walking characteristics. By controlling the chain walking process, various branched polyolefins with different topological structures can be produced. α-Diimine nickel metal catalysts have high activity and good thermal stability.

[0018] The function is to clear the trace oxygen, moisture, and other impurities that affect the activity of the catalyst in the reaction system. If only α-diimine nickel metal catalyst is added without a promoter, the activity of the catalyst will be reduced, the polymerization efficiency of the product will be reduced, and the product quality will be seriously affected;

[0019] Catalysts that can act to scavenge trace amounts of oxygen, moisture, and other impurities in the polymerization reaction system can also be used as co-catalysts.

[0020] Aluminum-based catalysts have a higher surface area and more acidic sites, are highly active, and have less environmental pollution. The proton transfer effect of aluminum-based catalysts can convert oxygen, water, etc.

[0021] In some embodiments, the aluminum-based catalyst is selected from the group consisting of diethylaluminum chloride, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldibenzylaluminum, ethyldi-p-tolylaluminum, or a mixture of any one or more of diethylbenzylaluminum.

[0022] In some embodiments, the molar ratio of the α-diimine nickel metal catalyst to the co-catalyst is 1:2000-3000.

[0023] Preferably, the molar ratio of the α-diimine nickel metal catalyst to the co-catalyst is 1:2000-2500.

[0024] More preferably, the molar ratio of the α-diimine nickel metal catalyst to the co-catalyst is 1:2300-2500, specifically 1:2400.

[0025] In some embodiments, the temperature for catalyzing the polymerization of ethylene to produce the ethylene-based polyolefin elastomer is 60-80° C. and the time is 25-30 hours.

[0026] Preferably, the temperature for catalyzing the polymerization of ethylene to produce the vinyl polyolefin elastomer is 65-75° C. and the time is 28 hours.

[0027] Preferably, the pressure for catalyzing the polymerization of ethylene to produce the ethylene-based polyolefin elastomer is 2 to 4 MPa; preferably 2.5 to 3.5 MPa; and more preferably 3 MPa.

[0028] Preferably, the vinyl polyolefin elastomer has a melt index of 7 to 10 g / 10 min, a number average molecular weight of 150,000 to 200,000, a molecular weight distribution of 1.0 to 1.3, a melting point of 63 to 65° C., and a density of 0.860 g / cm 3 .

[0029] In some embodiments, the mass ratio of the vinyl polyolefin elastomer, POE, antioxidant and crosslinking agent is 80-90:5-10:0.5-1:0.2-1.

[0030] Preferably, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] or tris[2,4-di-tert-butylphenyl]phosphite.

[0031] Preferably, the cross-linking agent is one or a combination of any of cumene peroxide, di-tert-butyl peroxide, diisopropylbenzene hydroperoxide, 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane, 4,4-di(tert-amylperoxy) valeric acid n-butyl ester, tert-butyl peroxy 2-ethylhexyl carbonate and ethyl 3,3-di(tert-butylperoxy)butyrate.

[0032] In some embodiments, the temperature of the melt refining is 80-150°C.

[0033] In some embodiments, the rotation speed during mixing is 1000-1500 r / min, and the mixing time is 20-30 min.

[0034] In a second aspect, the present invention provides a highly weather-resistant photovoltaic adhesive film prepared by the preparation method.

[0035] In a third aspect, the present invention provides application of the highly weather-resistant photovoltaic adhesive film in solar cell encapsulation.

[0036] The beneficial effects achieved by one or more embodiments of the present invention are as follows:

[0037] Vinyl elastomer is produced by catalyzing the polymerization of ethylene using an α-diimine nickel metal catalyst and a main catalyst. The catalyst has high thermal stability and activity in the catalytic reaction and can catalyze the polymerization of ethylene without the participation of α-olefins to produce vinyl polyolefin elastomers with excellent performance indicators.

[0038] Compared with traditional photovoltaic films, the vinyl polyolefin elastomer photovoltaic film of the present invention has significantly lower cost and significantly improved weather resistance. DETAILED DESCRIPTION

[0039] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0040] The present invention will be further described below in conjunction with the embodiments.

[0041] Example 1

[0042] The preparation method of vinyl polyolefin elastomer is as follows: n-heptane is used as solvent, α-diimine catalyst is used as catalyst, diethylaluminum chloride is used as co-catalyst, ethylene is used as raw material, slurry process is used for polymerization, reaction temperature is 60-85°C, reaction pressure is 2-4MPa, the ratio of α-diimine catalyst to co-catalyst is 1:2400, ethylene is introduced at an appropriate rate, three reactors are connected in series, and the reaction heat is removed by the jacketed tube coil. The polymer melt in the third reactor enters the ethylene flash tower for flash evaporation, the flash temperature is 160-200°C, and the flash pressure is 2MPa, so as to remove the unreacted monomers and terminate the reaction. The flash bottom solution is pumped to the adsorption tower, heated to 180°C, and then adsorbed by the molecular sieve and alumina filled in the tower to remove the unreacted catalyst and co-catalyst. The adsorbed rubber liquid enters the first flash tank with a temperature of 150-200°C and a pressure of 0.1-0.5MPa. The rubber liquid with most of the solvent flashed off enters the second flash tank with a pressure of -5Kpa, a temperature of 240°C, and a vacuum. After accumulating to a certain liquid level, it is pressurized by the second flash discharge pump and then drawn through the die head. After being water cooled, it is pelletized to obtain vinyl polyolefin elastomer pellets.

[0043] The raw materials of low-cost and high-weather-resistant photovoltaic adhesive film are composed of 80 parts of vinyl polyolefin elastomer, 5 parts of POE, 0.6 parts of antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol, and 0.3 parts of cross-linking agent cumene peroxide;

[0044] The preparation method comprises the following steps:

[0045] 1. Weigh the raw materials according to the proportion and mix them evenly in a high-speed mixer;

[0046] 2. The mixed raw materials are added into the extruder for melt mixing, extrusion, and casting into a film, and then rolled up to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0047] The speed of the high-speed mixer was set to 1000 r / min, the mixing time was set to 20 min, the melting and refining temperature was set to 85° C., and the melting and refining time was 30 min.

[0048] Example 2

[0049] The raw materials of the low-cost and high-weather-resistant photovoltaic adhesive film are composed of 85 parts of vinyl polyolefin elastomer, 7 parts of POE, 0.8 parts of antioxidant tris[2,4-di-tert-butylphenyl]phosphite, and 0.5 parts of cross-linking agent di-tert-butyl peroxide.

[0050] The preparation method comprises the following steps:

[0051] 1. Weigh all the raw materials according to the proportion and mix them evenly in a high-speed mixer.

[0052] 2. The mixed raw materials are added into the extruder for melt mixing, extrusion, and casting into a film, and then rolled up to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0053] The speed of the high-speed mixer was set to 1300 r / min, the mixing time was set to 25 min, the melting and refining temperature was set to 90° C., and the melting and refining time was 35 min.

[0054] Example 3

[0055] The raw materials of the low-cost and high-weather-resistant photovoltaic adhesive film are composed of 88 parts of vinyl polyolefin elastomer, 5 parts of POE, 0.7 parts of antioxidant tris[2,4-di-tert-butylphenyl]phosphite, and 0.6 parts of cross-linking agent diisopropylbenzene hydroperoxide.

[0056] The preparation method comprises the following steps:

[0057] 1. Weigh all the raw materials according to the proportion and mix them evenly in a high-speed mixer.

[0058] 2. The mixed raw materials are added into the extruder for melt mixing, extrusion, and casting into a film, and then rolled up to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0059] The speed of the high-speed mixer was set to 1500 r / min, the mixing time was set to 20 min, the melting and refining temperature was set to 95 °C, and the melting and refining time was set to 45 min;

[0060] Example 4

[0061] The raw materials of the low-cost and high-weather-resistant photovoltaic adhesive film are composed of 90 parts of vinyl polyolefin elastomer, 6 parts of POE, 0.75 parts of antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, and 0.65 parts of cross-linking agent 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane;

[0062] The preparation method comprises the following steps:

[0063] 1. Weigh all the raw materials according to the proportion and mix them evenly in a high-speed mixer.

[0064] 2. The mixed raw materials are added into the extruder for melt mixing, extrusion, and casting into a film, and then rolled up to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0065] The speed of the high-speed mixer was set to 1400 r / min, the mixing time was set to 30 min, the melting and refining temperature was set to 90° C., and the melting and refining time was 40 min.

[0066] Example 5

[0067] The raw materials of the low-cost and high-weather-resistant photovoltaic adhesive film are composed of 87 parts of vinyl polyolefin elastomer, 10 parts of POE, 0.8 parts of antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol, and 0.68 parts of cross-linking agent 4,4-di(tert-amylperoxy)valeric acid n-butyl ester by weight;

[0068] The preparation method comprises the following steps:

[0069] 1. Weigh all the raw materials according to the proportion and mix them evenly in a high-speed mixer.

[0070] 2. The mixed raw materials are added into the extruder for melt mixing, extrusion, and casting into a film, and then rolled up to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0071] The speed of the high-speed mixer was set to 1500 r / min, the mixing time was set to 25 min, the melting and refining temperature was set to 100° C., and the melting and refining time was 45 min.

[0072] Comparative Example 1

[0073] The raw materials of the low-cost and high-weather-resistant photovoltaic adhesive film are composed of: 0 parts of vinyl polyolefin elastomer, 86 parts of POE, 0.75 parts of antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, and 0.65 parts of cross-linking agent cumene peroxide;

[0074] The preparation method comprises the following steps:

[0075] 1. Weigh all the raw materials according to the proportion and mix them evenly in a high-speed mixer.

[0076] 2. The mixed raw materials are added into the extruder for melt mixing, extrusion, and casting into a film, and then rolled up to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0077] The speed of the high-speed mixer was set to 1400 r / min, the mixing time was set to 30 min, the melting and refining temperature was set to 90° C., and the melting and refining time was 30 min.

[0078] Comparative Example 2

[0079] The raw materials of the low-cost and high-weather-resistant photovoltaic adhesive film are composed of 80 parts of EVA, 6 parts of POE, 0.75 parts of antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol, and 0.65 parts of cross-linking agent cumene peroxide.

[0080] The preparation method comprises the following steps:

[0081] 1. Weigh all the raw materials according to the proportion and mix them evenly in a high-speed mixer.

[0082] 2. The mixed raw materials are added into the extruder for melt mixing, extrusion, and casting into a film, and then rolled up to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0083] The speed of the high-speed mixer was set to 1400 r / min, the mixing time was set to 30 min, the melting and refining temperature was set to 90° C., and the melting and refining time was 30 min.

[0084] Comparative Example 3

[0085] The raw materials of the low-cost and high-weather-resistant photovoltaic adhesive film are composed of 86 parts of EVA, 0 parts of POE, 0.75 parts of antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, and 0.65 parts of cross-linking agent cumene peroxide;

[0086] The preparation method comprises the following steps:

[0087] 1. Weigh all the raw materials according to the proportion and mix them evenly in a high-speed mixer.

[0088] 2. Add the mixed raw materials into the extruder for melt mixing, extrusion, casting into film, and winding to obtain the vinyl polyolefin elastomer (EPOE) photovoltaic film.

[0089] The speed of the high-speed mixer was set to 1400 r / min, the mixing time was set to 30 min, the melting and refining temperature was set to 90° C., and the melting and refining time was 30 min.

[0090] test

[0091] The film is made into a photovoltaic module with the same polycrystalline silicon cell, glass and backplane using the same process. The specific stacking order is tempered glass, photovoltaic film, polycrystalline silicon cell, photovoltaic film, backplane, and transferred to a laminator for heating. Vacuum is drawn at 145°C to remove bubbles. After curing for 15 minutes, a single-glass photovoltaic module can be obtained.

[0092] According to IEC TS 62804-1 "Test Method for Voltage-Induced Degradation Detection of Photovoltaic Modules", the power attenuation of photovoltaic modules before and after PID test was measured after 240 hours at 85°C and 90% relative humidity. The volume resistivity of the sample was tested according to the provisions of GB / T1410-2006. After irradiation with a 300W xenon lamp for 480 hours in a closed environment with a humidity of 90% and a temperature of 85°C, the transmittance at 380-1100nm was tested according to the national standard GB2410-2008. The results are shown in Table 1.

[0093] Table 1

[0094] PID attenuation rate % Volume resistivity Ω·cm Transmittance after aging % Example 1 5.8 6.15 90.73 Example 2 5.7 6.18 90.75 Example 3 5.5 6.22 90.82 Example 4 5.3 6.21 90.84 Example 5 5.2 6.23 90.88 Comparative Example 1 5.1 6.20 90.25 Comparative Example 2 6.7 6.16 84 Comparative Example 3 6.9 6.11 82

[0095] As shown in Table 1, the vinyl polyolefin elastomer high weather resistance photovoltaic composite film of the present invention has significantly improved anti-PID performance and high light transmittance after aging compared with EVA film, and has improved light transmittance after aging compared with POE. The cost of the vinyl polyolefin elastomer photovoltaic film is significantly lower than that of POE.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a highly weather-resistant photovoltaic adhesive film, characterized in that: The steps include: An α-diimide nickel metal catalyst and a co-catalyst are used to catalyze the polymerization of ethylene to produce a vinyl polyolefin elastomer; the vinyl polyolefin elastomer, POE, an antioxidant and a cross-linking agent are mixed in proportion, melt-mixed, extruded and cast into a film to obtain a vinyl polyolefin elastomer photovoltaic film; The structural formula of the α-diimine nickel metal catalyst is: Among them, R2, R7, R9, R 12 Each is independently selected from one of hydrogen, C1-C6 alkyl, halogen or halogenated C1-C6 alkyl; R1 and R8 are independently selected from one of hydrogen, C2-C6 alkyl, halogen or halogenated C2-C6 alkyl, nitro, C2-C6 alkoxy, and trifluoromethyl; R3, R6, R 10 , R 11 Each of them is independently selected from one of hydrogen, C2-C6 alkyl, halogen or halogenated C2-C6 alkyl, phenyl and diphenylmethyl; R4 and R5 are independently selected from hydrogen, C2-C6 alkyl, C2-C6 haloalkyl, phenyl, C6-C 30 Substituted phenyl; X is selected from halogen, C2-C6 alkane, C2-C6 alkene, allyl or benzyl; The co-catalyst is an aluminum-based catalyst.

2. The method for preparing a highly weather-resistant photovoltaic adhesive film according to claim 1, characterized in that: The aluminum-based catalyst is selected from any one or more of diethylaluminum chloride, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldibenzylaluminum, ethyldi-p-tolylaluminum or a mixture of diethylbenzylaluminum.

3. The method for preparing a highly weather-resistant photovoltaic adhesive film according to claim 1, characterized in that: The molar ratio of the α-diimine nickel metal catalyst to the co-catalyst is 1:2000-3000; Preferably, the molar ratio of the α-diimine nickel metal catalyst to the co-catalyst is 1:2000-2500; Preferably, the molar ratio of the α-diimine nickel metal catalyst to the co-catalyst is 1:2300-2500, specifically 1:2400.

4. The method for preparing a highly weather-resistant photovoltaic adhesive film according to claim 1, characterized in that: The temperature for catalyzing the polymerization of ethylene to produce vinyl polyolefin elastomer is 60-80°C and the time is 25-30h; Preferably, the temperature for catalyzing the polymerization of ethylene to produce the vinyl polyolefin elastomer is 65-75°C and the time is 28h; Preferably, the pressure for catalyzing the polymerization of ethylene to produce the ethylene-based polyolefin elastomer is 2 to 4 MPa; preferably 2.5 to 3.5 MPa; and more preferably 3 MPa.

5. The method for preparing a highly weather-resistant photovoltaic adhesive film according to claim 1, characterized in that: The vinyl polyolefin elastomer has a melt index of 7 to 10 g / 10 min, a number average molecular weight of 150,000 to 200,000, a molecular weight distribution of 1.0 to 1.3, a melting point of 63 to 65° C., and a density of 0.860 g / cm 3 .

6. The method for preparing a highly weather-resistant photovoltaic adhesive film according to claim 1, characterized in that: The mass ratio of vinyl polyolefin elastomer, POE, antioxidant and crosslinking agent is 80-90:5-10:0.5-1:0.2-1; Preferably, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] or tris[2,4-di-tert-butylphenyl]phosphite; Preferably, the cross-linking agent is one or a combination of any of cumene peroxide, di-tert-butyl peroxide, diisopropylbenzene hydroperoxide, 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane, 4,4-di(tert-amylperoxy) valeric acid n-butyl ester, tert-butyl peroxy 2-ethylhexyl carbonate and ethyl 3,3-di(tert-butylperoxy)butyrate.

7. The method for preparing a highly weather-resistant photovoltaic adhesive film according to claim 1, characterized in that: The melting and refining temperature is 80-150°C.

8. The method for preparing a highly weather-resistant photovoltaic adhesive film according to claim 1, characterized in that: The rotation speed during mixing is 1000-1500r / min, and the mixing time is 20-30min.

9. A highly weather-resistant photovoltaic film, characterized in that: Prepared by the preparation method described in any one of claims 1 to 8.

10. Use of the highly weather-resistant photovoltaic adhesive film according to claim 9 in solar cell packaging.

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