Multilayer film and solar cell encapsulation structure

Abstract

The present invention provides a multilayer film comprising: (A) an oxygen barrier layer; (B) a water vapor barrier layer on and directly contacting the (A) oxygen barrier layer; and (C) an adhesive layer on and directly contacting the (B) water vapor barrier layer. The (A) oxygen barrier layer comprises (a) a modified polyethylene resin and (e) an ethylene-vinyl alcohol copolymer. The (B) water vapor barrier layer comprises (b1) a first ethylene-1-octene copolymer having a melt index of 20 to 40 g / 10 min at 190°C and (b2) a second ethylene-1-octene copolymer having a melt index of 1 to 10 g / 10 min at 190°C. The (C) adhesive layer comprises an ethylene-methyl acrylate-glycidyl methacrylate copolymer having a melt index of 1 to 10 g / 10 min at 190°C.

Description

Technical Field

[0001] This invention specifically relates to multilayer films, and more particularly to multilayer films used in solar cell encapsulation structures. Background Technology

[0002] Perovskite solar cells (PSCs) can be connected in series with traditional silicon solar cells to fully utilize the advantages of sunlight and improve solar energy utilization. However, perovskite materials are stacked using coordination bonds rather than covalent bonds, making them less stable (sensitive to heat, ambient moisture, and oxygen), thus limiting the types of encapsulation materials that can be used. The water and oxygen barrier properties of the encapsulation material are crucial. Therefore, improving the water and oxygen barrier capabilities of the encapsulation film is an important challenge for PSCs. Summary of the Invention

[0003] An embodiment of the present invention provides a multilayer film comprising: (A) an oxygen barrier layer; (B) a water vapor barrier layer located on and in direct contact with the oxygen barrier layer; and (C) an adhesive layer located on and in direct contact with the water vapor barrier layer. The (A) oxygen barrier layer comprises (a) a modified polyethylene resin and (e) an ethylene-vinyl alcohol copolymer. The (B) water vapor barrier layer comprises (b1) a first ethylene-1-octene copolymer with a melt index of 20 to 40 g / 10 min at 190°C and (b2) a second ethylene-1-octene copolymer with a melt index of 1 to 10 g / 10 min at 190°C. The (C) adhesive layer comprises an ethylene-methyl acrylate-glycidyl methacrylate copolymer with a melt index of 1 to 10 g / 10 min at 190°C.

[0004] An embodiment of the present invention provides a solar cell encapsulation structure comprising: a solar cell; the aforementioned multilayer film encapsulating the solar cell; and a cover plate located on the multilayer film; wherein (A) an oxygen barrier layer of the multilayer film directly contacts the solar cell, and (C) an adhesive layer directly contacts the cover plate. Attached Figure Description

[0005] Figure 1 This is a schematic diagram of a multilayer film in one embodiment of the present invention;

[0006] Figure 2 This is a schematic diagram of a solar cell encapsulation structure in one embodiment of the present invention.

[0007] Symbol explanation:

[0008] 11: (A) Oxygen barrier layer;

[0009] 13: (B) Water-blocking air layer;

[0010] 15: (C) Adhesive layer;

[0011] 21: Solar cells;

[0012] 23: Cap;

[0013] 100: Multilayer film. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0015] like Figure 1 As shown, a multilayer film 100 provided in one embodiment of the present invention includes: (A) an oxygen barrier layer 11; (B) a water vapor barrier layer 13, located on and in direct contact with the oxygen barrier layer 11; and (C) an adhesive layer 15, located on and in direct contact with the water vapor barrier layer 13. In some embodiments, if the (A) gas barrier layer 11 is sandwiched between the (B) water vapor barrier layer 13 and the (C) adhesive layer 15, the adhesion between the (B) water vapor barrier layer and other components (such as solar cells) it contacts may be insufficient. In some embodiments, if the (C) adhesive layer 15 is sandwiched between the (A) oxygen barrier layer 11 and the (B) water vapor barrier layer 13, the adhesion between the (B) water vapor barrier layer 13 and other components (such as caps) formed thereon may be insufficient. On the other hand, if the composition of (A) oxygen barrier layer 11 and (B) water barrier layer 13 is mixed together instead of being a layered structure, the mixed single layer may be opaque and unsuitable for encapsulating solar cells.

[0016] In some embodiments, (A) the oxygen barrier layer 11 comprises (a) a modified polyethylene resin and (e) an ethylene-vinyl alcohol copolymer. In some embodiments, (a) the modified polyethylene resin comprises (a1) an ethylene-glycidyl methacrylate copolymer, (a2) an ethylene-acrylic acid copolymer, (a3) ​​an ethylene-methyl acrylate-maleic anhydride copolymer, or a combination thereof. For example, (a1) the ethylene-glycidyl methacrylate copolymer may be Arkema's LOTADER® AX8840 or Sumitomo Chemical's IGETABOND. TM BF-2C, GETABOND TMBF-E, or a combination thereof. For example, (a2) the ethylene-acrylic acid copolymer may be Dow Chemical's Nucrel 925, Dow Chemical's Nucrel 960, Dow Chemical's Nucrel 596, or a combination thereof. For example, (a3) ​​the ethylene-methyl acrylate-maleic anhydride copolymer may be Arkema's LOTADER® 4503, Arkema's LOTADER® 4403, Arkema's LOTADER® 4513T, or a combination thereof. In some embodiments, the weight ratio of (a) the modified polyethylene resin to (e) the ethylene-vinyl alcohol copolymer is 70:30 to 95:5. If the amount of (a) the modified polyethylene resin is too low, the hardness of (A) the oxygen barrier layer 11 may be too high to adhere to (B) the water vapor barrier layer 13. If the amount of (a) the modified polyethylene resin is too high, the oxygen barrier effect of (A) the oxygen barrier layer may be poor. In some embodiments, the thickness of (A) oxygen barrier layer 11 is 50 micrometers to 300 micrometers, or 100 micrometers to 300 micrometers. If the thickness of (A) oxygen barrier layer 11 is too small, the oxygen barrier effect of (A) oxygen barrier layer 11 may be insufficient. If the thickness of (A) oxygen barrier layer 11 is too large, the overall film material flexibility may be insufficient.

[0017] In some embodiments, (B) the water-blocking gas layer 13 comprises (b1) a first ethylene-1-octene copolymer with a melt index of 20 to 40 g / 10 min at 190°C and (b2) a second ethylene-1-octene copolymer with a melt index of 1 to 10 g / 10 min at 190°C. For example, (b1) the first ethylene-1-octene copolymer may be Engage, purchased from Dow Chemical. TM 8401, Dow Chemical's Engage TM 8402, or a combination thereof. For example, (b2) the second ethylene-1-octene copolymer may be Engage, purchased from Dow Chemical. TM 8450, Dow Chemical's Engagement TM8540, or a combination thereof. In some embodiments, the weight ratio of (b1) the first ethylene-1-octene copolymer to (b2) the second ethylene-1-octene copolymer is 85:15 to 65:35, or 80:20 to 70:30. If the proportion of (b1) the first ethylene-1-octene copolymer is too low, the encapsulation of (B) the water-blocking layer 13 may be insufficient. If the proportion of (b1) the first ethylene-1-octene copolymer is too high, the heat resistance of (B) the water-blocking layer 13 may be insufficient. In some embodiments, the thickness of (B) the water-blocking layer 13 is 100 micrometers to 300 micrometers. If the thickness of (B) the water-blocking layer 13 is too small, the water-blocking effect of (B) the water-blocking layer 13 may be poor. If the thickness of (B) the water-blocking layer 13 is too large, the multilayer film is too thick.

[0018] In some embodiments, (C) adhesive layer 15 comprises an ethylene-methyl acrylate-glycidyl methacrylate copolymer with a melt index of 1 to 10 g / 10 min at 190°C. If other materials, such as ethylene-glycidyl methacrylate copolymer, are used as (C) adhesive layer 15, the adhesive properties may be poor. If the melt index of the ethylene-methyl acrylate-glycidyl methacrylate copolymer is too low, the encapsulation properties may be insufficient. If the melt index of the ethylene-methyl acrylate-glycidyl methacrylate copolymer is too high, the anti-creep properties may be poor. In some embodiments, the thickness of (C) adhesive layer 15 is 100 micrometers to 300 micrometers. If the thickness of (C) adhesive layer 15 is too small, the adhesive effect may be poor. If the thickness of (C) adhesive layer 15 is too large, the multilayer film thickness is excessive.

[0019] In some embodiments, (A) an oxygen barrier layer 11, (B) a water vapor barrier layer 13, and (C) an adhesive layer 15 can be formed separately, and then the three layers can be laminated together and hot-pressed to form a multilayer film 100. In other embodiments, the multilayer film 100 can be formed by co-extrusion.

[0020] The aforementioned multilayer film 100 can be used in the solar cell encapsulation structure 200, such as... Figure 2 As shown. It is understood that the multilayer film 100 can also be used in other devices and is not limited to the solar cell encapsulation structure 200.

[0021] like Figure 2 As shown, the solar cell encapsulation structure 200 includes a solar cell 21; the aforementioned multilayer film 100 encapsulating the solar cell 21; and a cover plate 23 located on the multilayer film 100. The (A) oxygen barrier layer 11 of the multilayer film 100 directly contacts the solar cell 21, and the (C) adhesive layer 15 directly contacts the cover plate 23. Figure 2As shown, the solar cell encapsulation structure 200 may include another multilayer film 100 located below the solar cell 21, and another cover plate 23 located below the other multilayer film 100. Similarly, the (A) barrier layer 11 of the other multilayer film 100 directly contacts the solar cell 21, and the adhesive layer 15 directly contacts the other cover plate 23. In some embodiments, the multilayer films 21 above and below the solar cell 21 may be the same or different, depending on the requirements. In some embodiments, the cover plates 23 above and below the solar cell 21 may be the same or different, depending on the requirements.

[0022] In some embodiments, cover plate 23 includes a glass cover plate. In some embodiments, solar cell 21 includes a perovskite solar cell or an n-type silicon solar cell.

[0023] The aforementioned multilayer films simultaneously possess low water vapor permeability, excellent oxygen barrier properties, and flexible characteristics, enabling solar cell encapsulation structures to have better stability and longer lifespan.

[0024] To make the above-mentioned and other objects, features and advantages of the present invention more apparent and understandable, embodiments are described below in conjunction with the accompanying drawings for detailed explanation:

[0025] [Example]

[0026] Example 1

[0027] Engage purchased from Dow Chemical TM 8401 (melt index of 30 g / 10 min at 190 °C) was used as (b1) the first ethylene-1-octene copolymer, and Engage was purchased from Dow Chemical. TM 8450 (melt index of 3 g / 10 min at 190℃) was used as (b2) the second ethylene-1-octene copolymer. Different weight ratios of (b1) the first ethylene-1-octene copolymer and (b2) the second ethylene-1-octene copolymer were mixed and extruded into films with a thickness of 200 micrometers to confirm their encapsulation properties (viscosity must be less than 3000 Pa). The measurement standard is flat plate rheology at 120℃, sample thickness 1mm, frequency 1Hz) and heat resistance (creep temperature must be greater than 100℃, measurement standard is two 5cm plates). 5cm 3mm glass is laminated and vertically suspended in a hot air oven, heated until the glass slides more than 1mm. A film formed from 100 parts by weight of (b1) ethylene-1-octene copolymer has encapsulation properties but no heat resistance. A film formed from a blend of 90 parts by weight of (b1) ethylene-1-octene copolymer and 10 parts by weight of (b2) ethylene-1-octene copolymer has encapsulation properties but no heat resistance. A film formed from a blend of 80 parts by weight of (b1) ethylene-1-octene copolymer and 20 parts by weight of (b2) ethylene-1-octene copolymer has both encapsulation properties and heat resistance. A film formed from a blend of 70 parts by weight of (b1) ethylene-1-octene copolymer and 30 parts by weight of (b2) ethylene-1-octene copolymer has both encapsulation properties and heat resistance. A film formed from a blend of 60 parts by weight of (b1) first ethylene-1-octene copolymer and 40 parts by weight of (b2) second ethylene-1-octene copolymer has heat resistance but no encapsulation properties. A film formed from 100 parts by weight of (b2) second ethylene-1-octene copolymer has heat resistance but no encapsulation properties. In the following examples, a film formed from a blend of 70 parts by weight of (b1) first ethylene-1-octene copolymer and 30 parts by weight of (b2) second ethylene-1-octene copolymer is used as the (B) water-blocking vapor layer.

[0028] Engage TM 8401 consists of repeating units With repeating units Composition, in which repeating units With repeating units The weight ratio is 69:31. On the other hand, the above copolymer is a random copolymer rather than a block copolymer. TM 8450 consists of repeating units With repeating units Composition, in which repeating units With repeating units The weight ratio is 80:20. On the other hand, the above copolymer is a random copolymer rather than a block copolymer.

[0029] Example 2

[0030] LOTADER® AX8840 ((a1) ethylene-glycidyl methacrylate copolymer) purchased from Arkema was used as (a) modified polyethylene resin, and EV4451 (ethylene-vinyl alcohol copolymer, ethylene segment 44 mol%) purchased from Changchun Petrochemical Co., Ltd. was used as (e) ethylene-vinyl alcohol copolymer. Different weight ratios of (a1) ethylene-glycidyl methacrylate copolymer and (e) ethylene-vinyl alcohol copolymer were mixed, extruded into a film with a thickness of 200 micrometers, and laminated to the (B) water-blocking layer of Example 1 (a mixture of 70 parts by weight of (b1) first ethylene-1-octene copolymer and 30 parts by weight of (b2) second ethylene-1-octene copolymer, film thickness 200 micrometers) to confirm its peel strength to the (B) water-blocking layer (measured according to ASTM D3330). The peel strength of a film formed from 100 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer is 12.7 N / 15 mm. The peel strength of a film formed from a blend of 85 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 15 parts by weight of (e) ethylene-vinyl alcohol copolymer is 10.9 N / 15 mm. The peel strength of a film formed from a blend of 70 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 30 parts by weight of (e) ethylene-vinyl alcohol copolymer is 8.8 N / 15 mm. The peel strength of a film formed from a blend of 50 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 50 parts by weight of (e) ethylene-vinyl alcohol copolymer is 4.5 N / 15 mm. The peel strength of the film formed by a blend of 40 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 60 parts by weight of (e) ethylene-vinyl alcohol copolymer is 3.5 N / 15 mm. The peel strength of the film formed by a blend of 30 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 70 parts by weight of (e) ethylene-vinyl alcohol copolymer is 2.5 N / 15 mm. The peel strength of the film formed by 100 parts by weight of (e) ethylene-vinyl alcohol copolymer is 0.12 N / 15 mm. As can be seen from the above, when the proportion of (e) ethylene-vinyl alcohol copolymer in the (A) oxygen barrier layer exceeds 30% by weight, its adhesion strength (i.e., peel strength) with the (B) water barrier layer decreases significantly, and peeling may occur during the encapsulation process.

[0031] Arkema's LOTADER® AX8840 consists of repeating units With repeating units Composition, in which repeating units With repeating units The weight ratio is 92:8. On the other hand, the above copolymer is a random copolymer rather than a block copolymer. EV4451 consists of repeating units. With repeating units Composition, in which repeating units With repeating units The weight ratio is 44:56. On the other hand, the above copolymer is a random copolymer rather than a block copolymer.

[0032] Example 3

[0033] LOTADER® AX8840 ((a1) ethylene-glycidyl methacrylate copolymer) purchased from Arkema was used as (a) modified polyethylene resin, and EV4451 purchased from Changchun Petrochemical Co., Ltd. was used as (e) ethylene-vinyl alcohol copolymer. Different weight ratios of (a1) ethylene-glycidyl methacrylate copolymer and (e) ethylene-vinyl alcohol copolymer were mixed, extruded into a film with a thickness of 200 micrometers, and laminated to the (B) water-blocking layer of Example 1 (a mixture of 70 parts by weight of (b1) first ethylene-1-octene copolymer and 30 parts by weight of (b2) second ethylene-1-octene copolymer, film thickness 200 micrometers) to form a multilayer film. The transparency of the multilayer film was measured (greater than 85%, measured with a haze meter (NIPPON DENSHOKU NDH 2000, standard ASTM D1003), the oxygen permeability (OTR, standard ASTM F1307), the water vapor permeability (WVTR, standard ASTM F1249 38℃ / 100%RH), and the Young's coefficient of the multilayer film (standard ASTM D638).

[0034] The multilayer film formed by 100 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer, consisting of an oxygen barrier layer (A) and a water barrier layer (B), exhibits good transparency and an OTR of 608 cc / m. 2 day, WVTR is 1.94g / m 2 The day, and Young's coefficient is 29.0 MPa. The multilayer film formed by 85 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 15 parts by weight of (e) ethylene-vinyl alcohol copolymer, consisting of an oxygen barrier layer (A) and a water barrier layer (B), exhibits good transparency and an OTR of 551 cc / m. 2 day, WVTR is 1.82g / m 2 The day, and Young's coefficient is 33.2 MPa. The multilayer film formed by 70 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 30 parts by weight of (e) ethylene-vinyl alcohol copolymer, consisting of an oxygen barrier layer (A) and a water barrier layer (B), exhibits good transparency and an OTR of 394 cc / m. 2 day, WVTR is 1.74g / m 2 day, and Young's coefficient is 35.2 MPa.

[0035] Example 4

[0036] Nucrel 925 ((a2) ethylene-acrylic acid copolymer) purchased from Dow Chemical was used as (a) modified polyethylene resin, and EV4451 purchased from Changchun Petrochemical Co., Ltd. was used as (e) ethylene-vinyl alcohol copolymer. Different weight ratios of (a2) ethylene-glycidyl methacrylate copolymer and (e) ethylene-vinyl alcohol copolymer were mixed, extruded into a film with a thickness of 200 micrometers, and laminated to the (B) water-blocking gas layer of Example 1 (a mixture of 70 parts by weight of (b1) first ethylene-1-octene copolymer and 30 parts by weight of (b2) second ethylene-1-octene copolymer, with a film thickness of 200 micrometers) to form a multilayer film. The transparency of the multilayer film must be greater than 85%, measured with a haze meter (purchased from NIPPON DENSHOKU NDH 2000, standard ASTM D1003), the oxygen permeability (OTR, measurement standard ASTM F1307), the water vapor permeability (WVTR, measurement standard ASTM F1249 38℃ / 100%RH), and the Young's coefficient of the multilayer film (measurement standard ASTM D638) were measured.

[0037] The multilayer film formed by 100 parts by weight of (a2) ethylene-acrylic acid copolymer, consisting of an oxygen barrier layer (A) and a water vapor barrier layer (B), exhibits good transparency and an OTR of 313 cc / m. 2 day, WVTR is 1.38g / m 2 The day, and the Young's coefficient is 40.6 MPa. The multilayer film formed by 85 parts by weight of (a2) ethylene-acrylic acid copolymer and 15 parts by weight of (e) ethylene-vinyl alcohol copolymer, consisting of an oxygen barrier layer (A) and a water vapor barrier layer (B), exhibits good transparency and an OTR of 269 cc / m. 2 day, WVTR is 1.31g / m 2 The day, and Young's coefficient is 43.1 MPa. The multilayer film formed by 70 parts by weight of (a2) ethylene-acrylic acid copolymer and 30 parts by weight of (e) ethylene-vinyl alcohol copolymer, consisting of an oxygen barrier layer (A) and a water vapor barrier layer (B), exhibits good transparency and an OTR of 224 cc / m. 2 day, WVTR is 1.06 g / m 2 day, and Young's coefficient is 45.2 MPa.

[0038] Nucrel 925 consists of repeating units With repeating units Composition, in which repeating units With repeating units The weight ratio is 85:15. On the other hand, the above copolymer is a random copolymer rather than a block copolymer.

[0039] Example 5

[0040] Lotader® 4503 ((a3) ethylene-methyl acrylate-maleic anhydride copolymer) purchased from Arkema was used as the (a) modified polyethylene resin, and EV4451 (purchased from Changchun Petrochemical Co., Ltd.) was used as the (e) ethylene-vinyl alcohol copolymer. Different weight ratios of (a3) ​​ethylene-methyl acrylate-maleic anhydride copolymer and (e) ethylene-vinyl alcohol copolymer were blended, extruded into a 200-micron thick film, and laminated to the (B) water-blocking layer of Example 1 (a blend of 70 parts by weight of (b1) first ethylene-1-octene copolymer and 30 parts by weight of (b2) second ethylene-1-octene copolymer, film thickness 200 microns) to form a multilayer film. The transparency of the multilayer film was measured (greater than 85%, measured with a haze meter (NIPPON DENSHOKU NDH2000, standard ASTM D1003), and the oxygen permeability (OTR) of the multilayer film was measured according to ASTM. F1307), to measure the water vapor permeability (WVTR) of the multilayer membrane (measurement standard is ASTM F1249 38℃ / 100%RH), and to measure the Young's coefficient of the multilayer membrane (measurement standard is ASTM D638).

[0041] The multilayer film formed by 100 parts by weight of (a3) ​​ethylene-methyl acrylate-maleic anhydride copolymer, consisting of an oxygen barrier layer (A) and a water vapor barrier layer (B), exhibits good transparency and an OTR of 823 cc / m. 2 day, WVTR is 2.79g / m 2 The day, and Young's coefficient is 22.8 MPa. The multilayer film formed by 85 parts by weight of (a3) ​​ethylene-methyl acrylate-maleic anhydride copolymer and (e) ethylene-vinyl alcohol copolymer, consisting of (A) an oxygen barrier layer and (B) a water barrier layer, exhibits good transparency and an OTR of 789 cc / m. 2 day, WVTR is 2.47g / m 2 The day, and Young's coefficient is 24.5 MPa. The multilayer film formed by 70 parts by weight of (a3) ​​ethylene-methyl acrylate-maleic anhydride copolymer and 30 parts by weight of (e) ethylene-vinyl alcohol copolymer, consisting of an oxygen barrier layer (A) and a water vapor barrier layer (B), exhibits good transparency and an OTR of 617 cc / m. 2 day, WVTR is 2.55g / m 2 day, and Young's coefficient is 24.7 MPa

[0042] Arkema's Lotader® Lotader 4503 consists of repeating units Repeating unit , and repeating units Composition, in which repeating units Repeating unit , and repeating units The weight ratio is 97.7:20:0.3. On the other hand, the above copolymer is a random copolymer rather than a block copolymer.

[0043] Example 6

[0044] LOTADER® AX8840 ((a1) ethylene-glycidyl methacrylate copolymer) purchased from Arkema was used as (a) modified polyethylene resin, and EV3251 (ethylene-vinyl alcohol copolymer, ethylene segment accounting for 32 mol%) purchased from Changchun Petrochemical Co., Ltd. was used as (e) ethylene-vinyl alcohol copolymer. Different weight ratios of (a1) ethylene-glycidyl methacrylate copolymer and (e) ethylene-vinyl alcohol copolymer were blended, extruded into a film with a thickness of 200 micrometers, and laminated to the (B) water-blocking layer of Example 1 (a mixture of 70 parts by weight of (b1) first ethylene-1-octene copolymer and 30 parts by weight of (b2) second ethylene-1-octene copolymer, film thickness 200 micrometers) to form a multilayer film. The transparency of the multilayer film was measured (greater than 85%, measured with a haze meter (NIPPON DENSHOKU NDH 2000, standard ASTM D1003), the oxygen permeability (OTR, standard ASTM F1307), the water vapor permeability (WVTR, standard ASTM F1249 38℃ / 100%RH), and the Young's coefficient of the multilayer film (standard ASTM D638).

[0045] The multilayer film formed by 100 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer, consisting of an oxygen barrier layer (A) and a water barrier layer (B), exhibits good transparency and an OTR of 608 cc / m. 2 day, WVTR is 1.94g / m 2 The day, and Young's coefficient is 29.0 MPa. The multilayer film formed by 85 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 15 parts by weight of (e) ethylene-vinyl alcohol copolymer, consisting of an oxygen barrier layer (A) and a water barrier layer (B), exhibits good transparency and an OTR of 467 cc / m. 2 day, WVTR is 1.54g / m 2 The day, and Young's coefficient is 36.8 MPa. The multilayer film formed by 70 parts by weight of (a1) ethylene-glycidyl methacrylate copolymer and 30 parts by weight of (e) ethylene-vinyl alcohol copolymer, consisting of an oxygen barrier layer (A) and a water barrier layer (B), exhibits good transparency and an OTR of 351 cc / m. 2 day, WVTR is 1.50g / m 2 day, and Young's coefficient is 40.9 MPa.

[0046] Comparative Example 1

[0047] LOTADER® AX8900 (ethylene-methyl acrylate-glycidyl methacrylate copolymer) purchased from Arkema was used as the modified polyethylene resin, and EV4451 purchased from Changchun Petrochemical Co., Ltd. was used as the (e) ethylene-vinyl alcohol copolymer. 85 parts by weight of the modified polyethylene resin and 15 parts by weight of the (e) ethylene-vinyl alcohol copolymer were blended and extruded to form an (A) oxygen barrier layer with a thickness of 200 micrometers. However, the (A) oxygen barrier film had poor transparency and was not suitable for multilayer films.

[0048] Arkema LOTADER® AX8900 consists of repeating units Repeating unit , and repeating units Composition, in which repeating units Repeating unit , and repeating units The weight ratio is 68:24:8. Furthermore, the aforementioned copolymer is a random copolymer rather than a block copolymer.

[0049] Comparative Example 2

[0050] Orevac® T9304 (ethylene / vinyl acetate copolymer-maleic anhydride copolymer) purchased from Arkema was used as the modified polyethylene resin, and EV4451 purchased from Changchun Petrochemical Co., Ltd. was used as the (e) ethylene-vinyl alcohol copolymer. 85 parts by weight of the modified polyethylene resin and 15 parts by weight of the (e) ethylene-vinyl alcohol copolymer were blended and extruded to form an oxygen barrier layer (A) with a thickness of 200 micrometers. However, the (A) oxygen barrier film had poor transparency and was not suitable for multilayer films.

[0051] Arkema Orevac® T9304 consists of repeating units Repeating unit , and repeating units Composition, in which repeating units Repeating unit , and repeating units The weight ratio is 74.4:25:0.16. Furthermore, the aforementioned copolymer is a random copolymer rather than a block copolymer.

[0052] Although the present invention has been disclosed above with several embodiments, it is not intended to limit the present invention. Any person skilled in the art can make any changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the claims.

[0053] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multilayer film, comprising: (A) Oxygen barrier layer; (B) Water barrier layer, located on (A) oxygen barrier layer and in direct contact with (A) oxygen barrier layer; as well as (C) Adhesive layer, located on (B) water-blocking gas layer and in direct contact with (B) water-blocking gas layer; Wherein (A) the oxygen barrier layer comprises (a) a modified polyethylene resin and (e) an ethylene-vinyl alcohol copolymer; Wherein (B) the water-blocking gas layer comprises (b1) a first ethylene-1-octene copolymer with a melt index of 20 to 40 g / 10 min at 190 °C and (b2) a second ethylene-1-octene copolymer with a melt index of 1 to 10 g / 10 min at 190 °C; and The adhesive layer (C) comprises an ethylene-methyl acrylate-glycidyl methacrylate copolymer with a melt index of 1 to 10 g / 10 min at 190°C.

2. The multilayer film according to claim 1, wherein, (a) The weight ratio of modified polyethylene resin to (e) ethylene-vinyl alcohol copolymer is 70:30 to 95:

5.

3. The multilayer film according to claim 1, wherein, (a) Modified polyethylene resins include (a1) ethylene-glycidyl methacrylate copolymer, (a2) ethylene-acrylic acid copolymer, (a3) ​​ethylene-methyl acrylate-maleic anhydride copolymer, or combinations thereof.

4. The multilayer film according to claim 1, wherein, (A) The thickness of the oxygen barrier layer is 50 micrometers to 300 micrometers.

5. The multilayer film according to claim 1, wherein, The weight ratio of (b1) the first ethylene-1-octene copolymer to (b2) the second ethylene-1-octene copolymer is 85:15 to 65:

35.

6. The multilayer film according to claim 1, wherein, (B) The thickness of the water-blocking air layer is 100 micrometers to 300 micrometers.

7. The multilayer film according to claim 1, wherein, (C) The thickness of the adhesive layer is 100 micrometers to 300 micrometers.

8. A solar cell encapsulation structure, comprising: A solar cell; The solar cell is encapsulated using the multilayer film as described in claim 1; as well as A cover plate is located on the multilayer film; In this multilayer film, the oxygen barrier layer (A) is in direct contact with the solar cell, and the adhesive layer (C) is in direct contact with the cover plate.

9. The solar cell encapsulation structure according to claim 8, wherein, The cover includes a glass cover.

10. The solar cell encapsulation structure according to claim 8, wherein, The solar cell includes perovskite solar cells or n-type silicon solar cells.

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