Polyolefin elastomers and their use in photovoltaic sealing films

Abstract

The present invention provides a method for preparing and using a polyolefin elastomer and its composition for photovoltaic sealing films. In the present invention, the polyolefin elastomer is a random or block polymer composed of ethylene and an α-olefin, and has a molecular weight Mw of 30,000 to 200,000, a PDI of 1.5 to 3, an MFR of 1 to 50 g / 10 min measured at 190°C under a load of 2.16 kg, and a density of 0.85 to 0.95 g / cm. 3 The monomer insertion rate is 10 to 65 wt%, and the polyolefin resin has a content of soluble substances at 40°C or less during the TGIC trichlorobenzene heating rinse process of 0.1% to 20%. When used in photovoltaic sealing adhesive films, compositions prepared with this elastomer have superior optical properties, electrical insulation properties, and PID resistance.

Description

[Technical Field]

[0001] The present invention relates to a polyolefin elastomer for photovoltaic sealing films, which belongs to the technical field of photovoltaic adhesive films. [Background technology]

[0002] A photovoltaic power generation device is a device that converts light energy into electrical energy through the action of a PN junction using a photovoltaic cell module, of which the most important core device is the photovoltaic cell module, which is a sandwich device with a solar cell in the center, photovoltaic adhesive films on both sides of the cell, and photovoltaic glass or backplates on both sides of the adhesive films, which are then heat-laminated to form a photovoltaic module.Since the overall operating life of a photovoltaic module is as long as 25 years, the sealing adhesive film of the module is extremely important; if the adhesive film expires, the module will be scrapped and its operating life will be reduced.

[0003] Currently, crystalline silicon PERC cells are still the mainstream solar cell in the market, but ensuring the long-term stable operation of PERC modules faces a severe challenge: the PID effect (potential-induced decay), which can reduce the output power of solar modules by 20%, and in severe cases, by more than 50%.

[0004] Although the actual cause of the PID effect has not yet been determined, the PID resistance of adhesive films remains the most important issue in the industry. The common method for improving the PID resistance of adhesive films in the industry is to add metal ion scavengers to photovoltaic adhesive films or ion conductive agents to the adhesive films. Although these methods can achieve good PID resistance by adjusting the adhesive film formulation, they still cannot fundamentally solve the problem. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention optimizes the optical and electrical performance of the particles, especially the PID performance, by preparing POE particles with a special microstructure and adjusting the content of micro-soluble substances in the particles, thereby achieving the preparation of a photovoltaic composition with high light transmittance and high PID resistance. [Means for solving the problem]

[0006] The technical solutions adopted by the present invention are as follows.

[0007] In one aspect, the present invention provides a polyolefin elastomer for a photovoltaic sealing film, the polyolefin elastomer being a random or block polymer composed of ethylene and an α-olefin, wherein the content of soluble matter at or below 40°C during a TGIC trichlorobenzene temperature-rising rinse is 0.1% to 20 wt%, for example, 0.2 wt%, 0.5 wt%, 1 wt%, 2 wt%, 5 wt%, 10 wt%, or 15 wt%, and further 0.1% to 15 wt%.

[0008] Furthermore, the molecular weight Mw is 30,000 to 200,000 (for example, 40,000, 50,000, 80,000, 100,000, or 150,000), the PDI is 1.5 to 3 (for example, 1.8, 2.0, 2.2, 2.5, or 2.8), the MFR measured under the conditions of 190°C and a load of 2.16 kg is 1 to 50 g / 10 min (for example, 2 g / 10 min, 4 g / 10 min, 5 g / 10 min, 8 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min, 30 g / 10 min, or 40 g / 10 min), and the density is 0.85 to 0.95 g / cm 3 (0.86g / cm 3 , 0.88g / cm 3 , 0.9g / cm 3 , 0.92g / cm 3 , 0.94g / cm 3 ) and 0.85 to 0.90 g / cm 3 The monomer insertion rate is 10 to 65 wt% (for example, 12 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 60 wt%), and further 20 to 65 wt%.

[0009] Furthermore, the volume resistivity of the polyolefin elastomer is 10 13 ~10 18 Ω cm, e.g., 2×10 13 Ω·cm, 5×10 13 Ω·cm, 10 14 Ω·cm, 5×10 14 Ω·cm, 10 15 Ω·cm, 5×10 15 Ω·cm, 10 16 Ω·cm, 5×10 16 Ω·cm, 10 17 Ω·cm, 5×10 17 Ω·cm.

[0010] Furthermore, in the polyolefin elastomer, the α-olefin is an olefin having 3 to 13 carbon atoms, and is preferably one or more of propylene, butene, hexene, octene, nonene, and decene.

[0011] Furthermore, for example, the structural formula of a polyolefin elastomer can be expressed as follows: [ka] Here, n is an integer of 0 to 10, for example, 1, 2, 3, 4, 5, 6, 7, 8, or 9. The values ​​of x, y, m may be of conventional choice in the art.

[0012] In a second aspect, the present invention provides a method for preparing the polyolefin elastomer described above.

[0013] Furthermore, the method for preparing the polyolefin elastomer for the photovoltaic sealing film includes the steps of: Cationic coordination polymerization is used, the solvent and α-olefin are mixed in a certain ratio and then poured into a reactor, and ethylene gas is introduced into the reactor at a temperature of 120-160°C (for example, 130°C, 140°C, 150°C), and the pressure is set to 1-5 MPa (for example, 2 MPa, 3 MPa, 4 MPa). Then, the main catalyst and the co-catalyst are added to the reactor, and the mixture is stirred and reacted for 3-15 minutes (for example, 4 minutes, 5 minutes, 8 minutes, 10 minutes, 12 minutes), to obtain a reactant solution; The method includes the steps of adding an inactivating agent to the system, allowing the reaction to proceed sufficiently, obtaining a product, and then cooling and drying the product to obtain a polymer.

[0014] In the preparation method, the solvent is selected from aliphatic hydrocarbon solvents and / or aromatic hydrocarbon solvents. Preferably, the aliphatic hydrocarbon solvent is one or more selected from n-butane, isobutane, n-pentane, cyclopentane, methylcyclopentane, methylenecyclopentane, n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, n-heptane, n-octane, n-nonane, and Isopar E. Preferably, the aromatic hydrocarbon solvent is one or more selected from benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, and dichlorotoluene.

[0015] The α-olefin is an olefin having 3 to 13 carbon atoms, and is preferably one or more of propylene, butene, hexene, octene, nonene, and decene.

[0016] The main catalyst is a metallocene catalyst and / or a post-metallocene catalyst, and may be selected from the group consisting of dimethylsilyl(Nt-butylamine)(tetramethylcyclopentadienyl)titanium dichloride, dimethylsilyl(Nt-butylamine)(tetramethylcyclopentadienyl)titanium dimethyl, dimethylsilyl(Nt-butylamine)(fluorenyl)titanium dichloride, (pentamethylcyclopentadienyl)titanium trimethoxide, diphenylmethylene(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, dimethyldisilylbis(2-methyl-4-phenyl-1-indenyl)zirconium dichloride, meso-dimethylsilylbis(1-indenyl)zirconium dichloride, bis(methylcyclopentadienyl)zirconium dichloride, bis(1,3-dimethylcyclopentadienyl)

[0046] Preferably, the diphenylsilyl bis(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, (cyclopentadienyl)(1,2-dimethoxyethane)zirconium trichloride, diphenylsilyl(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, rac-dimethylsilylbis(2-methyl-1-indenyl)zirconium dichloride, diphenylmethylenecyclopentadienyl(2,7-di-t-butyl-fluorenyl)zirconium dichloride, di-p-tolylmethylenecyclopentadienyl(2,7-di-t-butyl-fluorenyl)zirconium dichloride, dimethylbis(propylcyclopentadienyl)hafnium, bis(n-butylcyclopentadienyl)hafnium dichloride, and dimethylsilylenebis(2-methyl-4-phenylindenyl)zirconium dichloride are selected from the group consisting of bis(propylcyclopentadienyl)hafnium, bis(n-butylcyclopentadienyl)hafnium dichloride, and dimethylsilylenebis(2-methyl-4-phenylindenyl)zirconium dichloride. The amount of the main catalyst added can be determined by those skilled in the art based on the catalyst activity and the weight of the target product, and typically, the amount of the main catalyst added may be 1 to 10 ppm (e.g., 2 ppm, 4 ppm, 5 ppm, 8 ppm) based on the polymer weight.

[0017] The co-catalyst is at least one of alkylaluminum, organic boron compounds, and alkylaluminoxanes, and is preferably one or more of methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, and tris(pentafluorophenyl)borane. The amount of co-catalyst added is 200 to 9800 ppm (e.g., 250 ppm, 500 ppm, 1000 ppm, 2000 ppm, 5000 ppm, 8000 ppm, or 9000 ppm) based on the polymer weight.

[0018] The inactivating agent is a mixture of inactivating agent A and inactivating agent B, and the mixing mass ratio of the two is 1 to 5:1 to 5 (for example, 1:1, 1:2, 1:3, 1:4, 1:5, 2:1, 2:3, 2:5, 3:1, 3:2, 3:4, 3:5, 4:1, 4:3, 4:5, 5:1, 5:2, 5:3, 5:4), where inactivating agent A is water and / or an alcohol having 2 to 20 carbon atoms, and the alcohol is ethanol, ethylene glycol, n-propanol, glycerin, n-butanol, 2-butanol, neopentyl alcohol, 1,6-hexanediol, n-octanol, 2-ethylhexanol, benzyl alcohol, or n-decanol. , dodecyl alcohol, tetradecyl alcohol, and hexadecyl alcohol are preferred, and inactivating agent B is a ketone, and is preferably one or more of dimethyl ketone, diethyl ketone, butanone, methyl isobutyl ketone, valerophenone, ethyl octanone, methyl n-nonyl ketone, methylhexanophenone, 2-pyrrolidone, bicyclo[3.3.1]nonane-3,7-dione, dimethylcyclohexanedione, 2,2,6-trimethyl-1,4-cyclohexanedione, diphenylethanedione, 3-methyl-2,4-nonanedione, 1-phenyl-2,4-pentanedione, and 2,4-decanedione. The amount of inactivating agent used is 600 to 150,000 ppm (for example, 800 ppm, 1,000 ppm, 2,000 ppm, 5,000 ppm, 10,000 ppm, 50,000 ppm, 100,000 ppm, 120,000 ppm) by weight of the polymer.

[0019] In a further aspect, the present invention provides the use of the above polyolefin elastomer in the preparation of a photovoltaic sealing film.

[0020] Furthermore, the photovoltaic sealing film contains the above-mentioned polyolefin elastomer, crosslinking agent, crosslinking coagent, coupling agent, and antioxidant.

[0021] In one specific embodiment, the amount of each component used is: 100 parts by weight of polyolefin elastomer, the crosslinking agent is 0.1 to 5 parts by weight (for example, 0.2 parts by weight, 0.4 parts by weight, 1 part by weight, 1.5 parts by weight, 2.5 parts by weight, 4 parts by weight, 4.5 parts by weight), preferably 0.5 to 2 parts by weight; the crosslinking aid is 0.1 to 5 parts by weight (for example, 0.2 parts by weight, 0.4 parts by weight, 1 part by weight, 1.5 parts by weight, 2.5 parts by weight, 4 parts by weight, 4.5 parts by weight), and preferably 0.1 to 2 parts by weight; The coupling agent is 0.1 to 3 parts by weight (for example, 0.2 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight), and preferably 0.1 to 0.6 parts by weight; The antioxidant is contained in an amount of 0.01 to 1 part by weight (for example, 0.02 parts by weight, 0.04 parts by weight, 0.06 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.4 parts by weight, 0.8 parts by weight), preferably 0.05 to 0.5 parts by weight.

[0022] Furthermore, the crosslinking agent is a peroxide-based crosslinking agent, and examples thereof include t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxy-2-ethylhexyl carbonate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-amylperoxy)-3,3,5-trimethylcyclohexane, and 1,1-bis(t-amylperoxy)-3, These include, but are not limited to, one or more of 3,5-trimethylcyclohexane, 1,1-bis(t-amylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)butane, t-butylperoxy-2-ethylhexyl carbonate, t-amylperoxy(2-ethylhexyl) carbonate, and t-butylperoxy-3,3,5-trimethylhexanoate.

[0023] Furthermore, the crosslinking aid is one or more of polyfunctional acrylate-based substances, such as trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glycerin triacrylate, propoxylated glycerin triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, Examples of suitable acrylates include, but are not limited to, ditrimethylolpropane tetraacrylate, ditrimethylolpropane tetramethacrylate, propoxylated pentaerythritol tetraacrylate, tricyclodecane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 2-butyl-2-ethyl-1,3-propylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate.

[0024] Furthermore, the coupling agent is a silane-based coupling agent, including, but not limited to, one or more of γ-chloropropyl methoxysilane, dimethylvinylethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyl trimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyl trimethoxysilane, 3-(trimethoxysilyl)propyl-2-methyl-2-acrylate, anilinomethyltriethoxysilane, and octyltrimethoxysilane.

[0025] Further, the antioxidant is one or more of hindered phenol-based or phosphate-based antioxidants, and examples thereof include n-octadecyl-β-[3,5-di-t-butyl-4-hydroxyphenyl]propionate, pentaerythritol-tetra[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,2-bis[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, 2,2'-oxamido-bis[ethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)]propionate, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxyphenyl)propionate, tert-butyl-4-hydroxyphenylpropanamide), 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)trione, triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 4,6-bis(octylthiomethyl)-o-cresol, tris[2,4-di-t-butylphenyl]phosphite, bis[2,4-di-t-butylphenyl]pentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphate.

[0026] Furthermore, the preparation of the photovoltaic sealing film can adopt conventional methods in the art, such as high-temperature premixing of raw materials, melt extrusion, film casting, cooling slitting and winding processes. [Effects of the Invention]

[0027] The beneficial effects of the present invention are as follows:

[0028] The present invention can obtain a low content of soluble substances (less than 20%) at temperatures below 40°C, ensuring that the base resin has a low low molecular weight portion. On the other hand, it can obtain POE particles with high PID resistance, which does not require upgrading the adhesive film formulation and can fundamentally improve the PID resistance performance of the photovoltaic adhesive film. On the other hand, the resin has better optical performance and electrical insulation performance. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will be further described below with reference to specific examples. The examples according to the present invention are merely for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention.

[0030] In this application, unless otherwise specified, "parts" and "%" are calculated by weight.

[0031] Main materials: Ethylene-octene copolymer A (MFR 2 g / 10 min (190 °C, 2.16 kg), Mw 57000, PDI 2.8, density 0.87 g / cm 3 The octene content is 40 wt%, the soluble matter content below 40°C is 1 wt%, and it is self-made. Ethylene-octene copolymer B (MFR 5 g / 10 min (190 °C, 2.16 kg), Mw 70000, PDI 2.3, density 0.868 g / cm 3 The content of soluble substances below 40°C is 3 wt%, the content of octene is 33 wt%, and it is self-made. Ethylene-butene copolymer C (MFR 5 g / 10 min (190 °C, 2.16 kg), Mw 75000, PDI 2.2, density 0.877 g / cm 3 The content of soluble substances below 40°C is 5 wt%, the content of butene is 24 wt%, and it is self-made. Ethylene-hexene copolymer D (MFR 25 g / 10 min (190 °C, 2.16 kg), Mw 40000, PDI 2, density 0.875 g / cm 3 The hexene content is 30 wt% and the soluble matter content below 40°C is 7 wt%, self-made), Ethylene-octene copolymer E (MFR 35 g / 10 min (190 °C, 2.16 kg), Mw 100,000, PDI 2.5, density 0.873 g / cm 3 The octene content is 30 wt% and the soluble matter content below 40℃ is 15%. Ethylene-hexene copolymer F (MFR 3 g / 10 min (190 °C, 2.16 kg), Mw 13000, PDI 2.1, density 0.872 g / cm 3 , the hexane content is 35 wt%, the content of soluble matter below 40℃ is 38%, (self-made), Methylaluminoxane (Akzo, 10% toluene solution), Modified methylaluminoxane (Nouryon), Dimethylsilylenebis(2-methyl-4-phenylindenyl)zirconium dichloride (Yao Dexin Chemical Co., Ltd.), Di-p-tolylmethylenecyclopentadienyl (2,7-di-t-butyl-fluorenyl) zirconium dichloride (Infinity Scientific), dimethylsilyl (Nt-butylamine) (tetramethylcyclopentadienyl) titanium dimethyl (Jiangsu XinNuo Chemical Chemicals Co., Ltd.), dimethylbis(propylcyclopentadienyl) hafnium (Infinity Scientific), diphenylmethylenecyclopentadienyl (2,7-di-t-butyl-fluorenyl) zirconium dichloride (Yao Dexin Chemical Co., Ltd.), Dimethylsilyl(t-butylamino)tetramethylcyclopentadienyltitanium dimethyl (Sinocompound).

[0032] Test equipment: Melt indexer: ZwickMflow, test standard ASTM D1238. Extruder: Single screw extruder (L / D=35), screw diameter 30 mm. Molecular weight and insertion rate tester: Polymer Char, GPC-IR. Soluble matter analysis: Polymer Char, TGIC, uses trichlorobenzene as the solvent. TGIC separates and characterizes different components of polyolefins using a temperature-rush rinse method. The sample is dissolved in trichlorobenzene at 165°C and passed through a TGIC column. The temperature is then programmed to drop to 40°C (20°C / min). Some polyolefin structures adhere to the column through adsorption and crystallization with the graphite column. The column is then washed away at a flow rate of 0.5ml / min. The soluble matter is then passed through the IR5 detector for detection. The column is then heated to 165°C at a rate of 2°C / min. The molecules attached to the column are sequentially washed out according to their crystallization ability and the number of short-chain branches. PID device: Environmental box manufactured by Shanghai Zealwe Technology, model number EW-EC03PID02-021220. Power test device: Nanjing LixiTe, model number LXT-CELL. Resistance meter: KEITHLEY, model number 6517B, 1000V, 10min.

[0033] (Preparation example) Preparation of ethylene-octene copolymer A: Cationic metallocene coordination polymerization was used. 200g of octene was added to 1L of n-butane solvent to prepare a solution, which was then added to a reactor. The temperature was raised to 150°C, ethylene gas was introduced, and the pressure inside the reactor was controlled at 2.5MPa. 1mg of the main catalyst, dimethylsilylenebis(2-methyl-4-phenylindenyl)zirconium dichloride, and 5ml of the cocatalyst, a toluene solution of 10wt% methylaluminoxane, were added to the reactor and stirred for 15 minutes to obtain a reaction product solution.

[0034] Water and 3-methyl-2,4-nonanedione were mixed in a mass ratio of 3:1, and the mixture (1.2 g in total) was thoroughly reacted with the reactant solution. The resulting product was cooled, filtered, and dried to obtain ethylene-octene copolymer A. The copolymer had an MFR of 2 g / 10 min (190°C, 2.16 kg), an Mw of 57,000, a PDI of 2.8, and a density of 0.87 g / cm. 3 The octene content is 40 wt%, the soluble matter content below 40°C is 1 wt%, and the volume resistivity is 10 17 Ω·cm.

[0035] Preparation of ethylene-octene copolymer B: Cationic metallocene coordination polymerization was used. 190g of octene was added to 1L of Isopar E to form a solution, which was then added to a reactor. The temperature was raised to 150°C, ethylene gas was introduced, and the pressure inside the reactor was controlled at 2.5MPa. 0.87mg of the main catalyst di-p-tolylmethylenecyclopentadienyl(2,7-di-t-butyl-fluorenyl)zirconium dichloride and 7ml of the cocatalyst 10wt% methylaluminoxane toluene solution were added to the reactor and stirred for 15 minutes to obtain a reaction product solution.

[0036] Water and 3-methyl-2,4-nonanedione were mixed in a mass ratio of 4:1, and the mixture with a total mass of 900 mg was mixed with the reactant solution and allowed to react thoroughly. The resulting product was then cooled to obtain a solid precipitate, which was filtered and dried to obtain ethylene-octene copolymer B. The copolymer had an MFR of 5 g / 10 min (190°C, 2.16 kg), an Mw of 70,000, a PDI of 2.3, and a density of 0.868 g / cm. 3 The content of soluble matter below 40°C is 3 wt%, the content of octene is 33 wt%, and the volume resistivity is 10 17 Ω·cm.

[0037] Preparation of ethylene-butene copolymer C: Cationic metallocene coordination polymerization was used. 1L of Isopar E was placed in a reactor, heated to 140°C, and gas was introduced at a ratio of 1:1 ethylene:butene. The pressure inside the reactor was controlled at 3MPa. 0.8mg of the main catalyst dimethylsilyl(Nt-butylamine)(tetramethylcyclopentadienyl)titanium dimethyl and 8ml of the cocatalyst 7% Al Isopar E-modified methylaluminoxane solution were added to the reactor and stirred for 15 minutes to obtain the reaction product solution.

[0038] Water and 2-pyrrolidone were mixed in a 1:2 mass ratio, and the resulting mixture (600 mg in total mass) was thoroughly reacted with the reactant solution. The resulting product was cooled, filtered, and dried to obtain ethylene-butene copolymer C. The copolymer had an MFR of 5 g / 10 min (190 °C, 2.16 kg), an Mw of 75,000, a PDI of 2.2, and a density of 0.877 g / cm. 3 The content of soluble substances below 40°C is 5 wt%, the content of butene is 24 wt%, and the volume resistivity is 10 16 Ω·cm.

[0039] Preparation of ethylene-hexene copolymer D: Cationic metallocene coordination polymerization was used. 200g of hexene was added to 1L of Isopar E solvent to form a solution, which was then added to a reactor. The temperature was raised to 140°C, ethylene gas was introduced, and the pressure inside the reactor was controlled at 2.8MPa. 0.9mg of the main catalyst dimethylbis(propylcyclopentadienyl)hafnium and 3ml of the cocatalyst 10wt% methylaluminoxane toluene solution were added to the reactor and stirred for 15 minutes to obtain a reaction solution.

[0040] n-Butanol and 1-phenyl-2,4-pentanedione were mixed in a mass ratio of 2:3, and the mixture (400 mg in total mass) was thoroughly reacted with the reactant solution. The resulting product was cooled, filtered, and dried to obtain ethylene-hexene copolymer D. It had an MFR of 25 g / 10 min (190 °C, 2.16 kg), an Mw of 40,000, a PDI of 2, and a density of 0.875 g / cm. 3The hexene content is 30 wt%, the soluble matter content below 40°C is 7 wt%, and the volume resistivity is 10 15 Ω·cm.

[0041] Preparation of ethylene-octene copolymer E: Cationic metallocene coordination polymerization was used. 190g of octene was added to 1L of Isopar E solvent to form a solution, which was then added to a reactor. The temperature was raised to 150°C, ethylene gas was introduced, and the pressure inside the reactor was controlled at 3.5MPa. 1mg of the main catalyst, diphenylmethylenecyclopentadienyl(2,7-di-t-butyl-fluorenyl)zirconium dichloride, and 10ml of the cocatalyst, 7% Al Isopar E-modified methylaluminoxane solution, were added to the reactor and stirred for 15 minutes to obtain a reaction solution.

[0042] Ethanol and ethyl octanone were mixed in a mass ratio of 3:5, and then the mixture (200 mg in total mass) was thoroughly reacted with the reactant solution. The resulting product was cooled, filtered, and dried to obtain ethylene-octene copolymer E. The copolymer had an MFR of 35 g / 10 min (190°C, 2.16 kg), an Mw of 100,000, a PDI of 2.5, and a density of 0.873 g / cm. 3 The octene content is 30 wt%, the soluble matter content below 40°C is 15%, and the volume resistivity is 10 15 Ω·cm.

[0043] Preparation of ethylene-hexene copolymer F: Cationic metallocene coordination polymerization was used. 160g of octene was added to 1L of n-butane solvent to prepare a solution, which was then added to a reactor. The temperature was raised to 135°C, ethylene gas was introduced, and the pressure inside the reactor was controlled at 2.5MPa. 1mg of the main catalyst dimethylsilyl(t-butylamino)tetramethylcyclopentadienyltitanium dimethyl and 4ml of the cocatalyst 10wt% methylaluminoxane toluene solution were added to the reactor and stirred for 15 minutes to obtain a reaction product solution.

[0044] After the reaction solution was fully reacted with 100 mg of water, the resulting product was cooled, filtered, and dried to obtain ethylene-hexene copolymer F. The copolymer had an MFR of 3 g / 10 min (190 °C, 2.16 kg), an Mw of 13,000, a PDI of 2.1, and a density of 0.872 g / cm. 3 The hexane content is 35 wt%, the soluble matter content below 40°C is 38%, and the volume resistivity is 10 14 Ω·cm.

[0045] (Examples and Comparative Examples) Example 1 To 1000 g of ethylene-octene copolymer A, 9 g of t-butylperoxy-2-ethylhexyl carbonate, 5 g of triallyl isocyanurate, 2 g of γ-methacryloxypropyltrimethoxysilane, 1 g of γ-(2,3-glycidoxy)propyltrimethoxysilane, 1 g of bis[2,4-di-t-butylphenyl]pentaerythritol diphosphite, and 1 g of n-octadecyl-β-[3,5-di-t-butyl-4-hydroxyphenyl]propionate were added. The above raw materials were heated to 50°C and mixed uniformly. The extruder parameters were adjusted to obtain temperatures from the material inlet to the die head of 80°C, 90°C, 90°C, 90°C, 90°C, 95°C, 95°C, and 95°C. The screw rotation speed was 45 rpm, the take-up speed was 0.7 rpm, and the take-up speed was 1.3 rpm. After the extrusion, casting, cooling slit, and take-up processes, an encapsulating adhesive film for photovoltaic modules was produced, with a film thickness of 0.6 mm.

[0046] Example 2 To 1000 g of ethylene-octene copolymer B, 6 g of 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2 g of t-amylperoxy(2-ethylhexyl)carbonate, 4 g of trimethylolpropane triacrylate, 2 g of γ-methacryloxypropyltrimethoxysilane, 1 g of γ-(2,3-glycidoxy)propyltrimethoxysilane, 0.1 g of antioxidant 1076, and 1 g of antioxidant 1010 were added. The above raw materials were heated to 50°C and mixed uniformly. The extruder parameters were adjusted to obtain temperatures from the material inlet to the die head of 80°C, 90°C, 90°C, 90°C, 90°C, 95°C, 95°C, and 95°C. The screw rotation speed was 45 rpm, the take-up speed was 0.7 rpm, and the take-up speed was 1.3 rpm. After the extrusion, casting, cooling slit, and take-up processes, an encapsulating adhesive film for photovoltaic modules was produced, with a film thickness of 0.6 mm.

[0047] Example 3 1000g of ethylene-butene copolymer C was mixed with 20g of t-butylperoxy-2-ethylhexyl carbonate, 7g of triallyl isocyanurate, 8g of dimethylvinylethoxysilane, and 0.5g of pentaerythritol tetra[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]. The above raw materials were heated to 50°C and mixed uniformly. The extruder parameters were adjusted to the following temperatures from the material inlet to the die head: 80°C, 90°C, 90°C, 90°C, 90°C, 95°C, 95°C, 95°C. The screw rotation speed was 45 rpm, the take-up speed was 0.7 rpm, and the take-up speed was 1.3 rpm. After extrusion, casting, cooling, and take-up, a 0.6mm thick encapsulating adhesive film for photovoltaic modules was produced.

[0048] Example 4 To 1000 g of ethylene-hexene copolymer D, 15 g of 2,2-bis(t-butylperoxy)butane, 10 g of triallyl isocyanurate, 15 g of γ-methacryloxypropyltrimethoxysilane, 0.1 g of 1,2-bis[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine and 1 g of triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] were added. The above raw materials were heated to 50°C and mixed uniformly. The extruder parameters were adjusted to obtain temperatures from the material inlet to the die head of 80°C, 90°C, 90°C, 90°C, 90°C, 95°C, 95°C, and 95°C. The screw rotation speed was 45 rpm, the take-up speed was 0.7 rpm, and the take-up speed was 1.3 rpm. After the extrusion, casting, cooling slit, and take-up processes, an encapsulating adhesive film for photovoltaic modules was produced, with a film thickness of 0.6 mm.

[0049] Example 5 To 1000 g of ethylene-octene copolymer E, 10 g of t-butylperoxy-2-ethylhexyl carbonate, 8 g of triallyl isocyanurate, 2 g of octyltrimethoxysilane, 1 g of γ-(2,3-glycidoxy)propyltrimethoxysilane, 0.1 g of triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] and 1 g of bis[2,4-di-t-butylphenyl]pentaerythritol diphosphite were added. The above raw materials were heated to 50°C and mixed uniformly. The extruder parameters were adjusted to obtain temperatures from the material inlet to the die head of 80°C, 90°C, 90°C, 90°C, 90°C, 95°C, 95°C, and 95°C. The screw rotation speed was 45 rpm, the take-up speed was 0.7 rpm, and the take-up speed was 1.3 rpm. After the extrusion, casting, cooling slit, and take-up processes, an encapsulating adhesive film for photovoltaic modules was produced, with a film thickness of 0.6 mm.

[0050] (Comparative Example 1) To 1000 g of ethylene-hexene copolymer F, 9 g of t-butylperoxy-2-ethylhexyl carbonate, 5 g of triallyl isocyanurate, 2 g of γ-methacryloxypropyltrimethoxysilane, 1 g of γ-(2,3-glycidoxy)propyltrimethoxysilane, 1 g of bis[2,4-di-t-butylphenyl]pentaerythritol diphosphite, and 1 g of n-octadecyl-β-[3,5-di-t-butyl-4-hydroxyphenyl]propionate were added. The above raw materials were heated to 50°C and mixed uniformly. The extruder parameters were adjusted to obtain temperatures from the material inlet to the die head of 80°C, 90°C, 90°C, 90°C, 90°C, 95°C, 95°C, and 95°C. The screw rotation speed was 45 rpm, the take-up speed was 0.7 rpm, and the take-up speed was 1.3 rpm. After the extrusion, casting, cooling slit, and take-up processes, an encapsulating adhesive film for photovoltaic modules was produced, with a film thickness of 0.6 mm.

[0051] The sealing adhesive films prepared in the above examples and comparative examples were used to prepare photovoltaic modules, and their light transmittance and PID performance were tested, and the test results are shown in the table below.

[0052] The test method is as follows.

[0053] PID decay: The adhesive films prepared in each example and comparative example were used as the front and back sealing adhesive films for the same photovoltaic module. The photovoltaic module consisted of tempered glass, an upper sealing adhesive film, bifacial crystalline silicon cell pieces, a lower sealing adhesive film, and tempered glass. The module was vacuumed and pressurized at 150°C using a laminator, and crosslinked for 18 minutes. The power change before and after aging of the module was tested at HAST (85°C, 85% RH, -1500V, 192h).

[0054] Light transmittance test: The test was carried out according to the spectrophotometer method of GB / T 2410-2008, and the average light transmittance values ​​in the wavelength ranges of 290nm~380nm and 380nm~1100nm were calculated, respectively.

[0055] [Table 1]

[0056] By comparing the performance test data of the Examples and Comparative Examples shown in the above table, the following was found.

[0057] The polyolefin elastomer and composition for photovoltaic sealing adhesive films according to the present invention controls the content of soluble substances during the synthesis of the base resin, improving the PID resistance of the base resin itself. The photovoltaic adhesive film produced thereby achieves high PID resistance without the need to add anti-PID additives at the formulation level, enabling widespread use in the adhesive film field, reducing the need for additives, and also providing excellent optical performance.

[0058] It should be pointed out that the above is only a preferred embodiment of the present invention, and those skilled in the art may make some improvements or supplements without departing from the method of the present invention, and these improvements or supplements should also be considered as part of the protection scope of the present invention.

Claims

1. A polyolefin elastomer, the polyolefin elastomer is a random or block polymer composed of ethylene and an α-olefin, the α-olefin of the polyolefin elastomer being an olefin having 3 to 13 carbon atoms; The polyolefin elastomer has a content of soluble substances at 40°C or less in a TGIC trichlorobenzene temperature-rising rinse process of 0.1% to 15 wt %; The polyolefin elastomer has a molecular weight Mw of 30,000 to 200,000, a PDI of 1.5 to 3, an MFR of 1 to 50 g / 10 min under a load of 2.16 kg at 190°C, and a density of 0.85 to 0.90 g / cm ３ and the monomer insertion rate is 20 to 65 wt %. A polyolefin elastomer characterized by:

2. The volume resistivity of the polyolefin elastomer is 10 １３ ~10 １８ Ω cm, The polyolefin elastomer according to claim 1 .

3. The α-olefin is one or more selected from propylene, butene, hexene, octene, nonene, and decene. The polyolefin elastomer according to claim 1 or 2.

4. A method for preparing the polyolefin elastomer according to any one of claims 1 to 3, comprising the steps of: Mixing the solvent and the α-olefin, then pouring them into a reactor, and then blowing ethylene gas into the reactor at a certain temperature. Then, adding the main catalyst and the co-catalyst to the reactor and stirring to react with each other, thereby obtaining a reactant solution; adding an inactivating agent to the system, allowing it to react sufficiently, and then obtaining the product; the inactivating agent is a mixture of inactivating agent A and inactivating agent B, the mixing ratio of the two being 1-5:1-5; Wherein, inactivating agent A is water and / or an alcohol having 2 to 20 carbon atoms, and inactivating agent B is a ketone; Method for preparing polyolefin elastomers.

5. The main catalyst is a metallocene catalyst and / or a post-metallocene catalyst; 5. The method of claim 4.

6. The main catalyst may be dimethylsilyl(N-t-butylamine)(tetramethylcyclopentadienyl)titanium dichloride, dimethylsilyl(N-t-butylamine)(tetramethylcyclopentadienyl)titanium dimethyl, dimethylsilyl(N-t-butylamine)(fluorenyl)titanium dichloride, (pentamethylcyclopentadienyl)titanium trimethoxide, diphenylmethylene(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, meso-dimethylsilylbis(1-indenyl)zirconium dichloride, bis(methylcyclopentadienyl)zirconium dichloride, bis(1,3-dimethylcyclopentadienyl)zirconium dichloride, (cyclopentadienyl)(1, 2-dimethoxyethane)zirconium trichloride, diphenylsilyl(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, rac-dimethylsilylbis(2-methyl-1-indenyl)zirconium dichloride, diphenylmethylenecyclopentadienyl(2,7-di-t-butyl-fluorenyl)zirconium dichloride, di-p-tolylmethylenecyclopentadienyl(2,7-di-t-butyl-fluorenyl)zirconium dichloride, dimethylbis(propylcyclopentadienyl)hafnium, bis(n-butylcyclopentadienyl)hafnium dichloride, and dimethylsilylenebis(2-methyl-4-phenylindenyl)zirconium dichloride, 6. The method of claim 5.

7. The co-catalyst is at least one of alkylaluminum, organic boron compound, and alkylaluminoxane. The preparation method according to any one of claims 4 to 6.

8. The co-catalyst is one or more selected from methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, and tris(pentafluorophenyl)boron; 8. The method of claim 7.

9. the inactivating agent A is one or more selected from ethanol, ethylene glycol, n-propanol, glycerin, n-butanol, 2-butanol, neopentyl alcohol, 1,6-hexanediol, n-octanol, 2-ethylhexanol, benzyl alcohol, n-decanol, dodecyl alcohol, tetradecyl alcohol, and hexadecyl alcohol; The inactivating agent B is one or more selected from dimethyl ketone, diethyl ketone, butanone, methyl isobutyl ketone, valerophenone, ethyl octanone, methyl n-nonyl ketone, methylhexanophenone, 2-pyrrolidone, bicyclo[3.3.1]nonane-3,7-dione, dimethylcyclohexanedione, 2,2,6-trimethyl-1,4-cyclohexanedione, diphenylethanedione, 3-methyl-2,4-nonanedione, 1-phenyl-2,4-pentanedione, and 2,4-decanedione; 9. A method according to any one of claims 4 to 8.

10. Use of the polyolefin elastomer according to any one of claims 1 to 3 or the polyolefin elastomer prepared by the preparation method according to any one of claims 4 to 9 in the preparation of a photovoltaic sealing film.

11. A composition comprising the polyolefin elastomer according to any one of claims 1 to 3 or the polyolefin elastomer prepared by the preparation method according to any one of claims 4 to 9, a crosslinking agent, a crosslinking coagent, a coupling agent, and an antioxidant. Photovoltaic sealing film.

12. The amount of each component of the photovoltaic sealing film used is as follows: 100 parts by weight of polyolefin elastomer, 0.1 to 5 parts by weight of a crosslinking agent, The cross-linking aid is 0.1 to 5 parts by weight, 0.1 to 3 parts by weight of a coupling agent, The antioxidant is 0.01 to 1 part by weight.

12. The photovoltaic encapsulating film of claim 11.

13. the crosslinking agent is a peroxide-based crosslinking agent, and / or the coagent is one or more of a multifunctional acrylate-based material; and / or the coupling agent is a silane-based coupling agent, and / or The antioxidant is one or more of a hindered phenolic or phosphate ester antioxidant.

13. The photovoltaic encapsulating film of claim 11 or 12.

14. the crosslinking agent is one or more selected from t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxy-2-ethylhexyl carbonate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-amylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)butane, t-butylperoxy-2-ethylhexyl carbonate, t-amylperoxy(2-ethylhexyl)carbonate, and t-butylperoxy-3,3,5-trimethylhexanoate; and / or The crosslinking aid may be trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glycerin triacrylate, propoxylated glycerin triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, or ditrimethylolpropane tetraacrylate. one or more selected from the group consisting of ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 2-butyl-2-ethyl-1,3-propylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate; and / or The coupling agent is one or more selected from the group consisting of γ-chloropropyl methoxysilane, dimethylvinylethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyl trimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyl trimethoxysilane, 3-(trimethoxysilyl)propyl-2-methyl-2-acrylate, anilinomethyltriethoxysilane, and octyltrimethoxysilane, and / or The antioxidant may be n-octadecyl-β-[3,5-di-t-butyl-4-hydroxyphenyl]propionate, pentaerythritol-tetra[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,2-bis[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, 2,2'-oxamido-bis[ethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)]propionate, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxyphenylpropanamide), 1,3,5-trihydroxyphenylpropanamide, ... the base is one or more selected from the group consisting of bis(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)trione, triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 4,6-bis(octylthiomethyl)-o-cresol, tris[2,4-di-t-butylphenyl]phosphite, bis[2,4-di-t-butylphenyl]pentaerythritol diphosphite, and bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphate; 14. The photovoltaic encapsulating film of claim 13.

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