EPE packaging adhesive film and preparation method and application thereof

Abstract

The invention provides an EPE packaging adhesive film as well as a preparation method and application thereof. The EPE packaging adhesive film comprises a first EVA layer, a first POE layer, a second POE layer, a third POE layer and a second EVA layer which are sequentially stacked, the first EVA layer and the second EVA layer are prepared from the following raw materials: EVA particles, a cross-linking agent, an assistant cross-linking agent, high-functionality acrylic ester, a tackifier and a light stabilizer; the first POE layer and the third POE layer are prepared from the following raw materials: high-melt-index POE particles, low-melt-index POE particles, a cross-linking agent, an assistant cross-linking agent, conventional acrylic ester, a tackifier and a light stabilizer; the second POE layer is prepared from the following raw materials: POE particles with high melt index, a cross-linking agent, an assistant cross-linking agent, acrylate with low functionality, a tackifier and a light stabilizer. According to the EPE packaging adhesive film provided by the invention, the P-layer auxiliary agent migration rate is low, the overall thickness of the adhesive film is more uniform, and no bubble is generated after a wet freezing test.

Description

Technical Field

[0001] The invention belongs to the technical field of packaging films, and relates to an EPE packaging film and a preparation method and application thereof, and in particular to a low-additive migration type EPE packaging film for Topcon double-glass and a preparation method thereof. Background Art

[0002] With the development of photovoltaic modules, the conventional Perc (P-type) cells on the market are now close to their theoretical efficiency limit; major manufacturers have begun to promote the development of N-type cells because of their higher theoretical efficiency limit (28.7%). Topcon is the mainstream development direction of N-type cells, and some manufacturers have begun small-batch mass production of modules.

[0003] Topcon is divided into single-glass and double-glass module types. Since the upper and lower layers of double-glass modules are encapsulated with glass, unlike the single-glass backplane, the water vapor permeability is low and the requirements for the encapsulation film are lower than those for single-glass modules. Single-glass modules require POE+white EVA / EPE for encapsulation, while double-glass modules require EPE+transparent EVA / EPE for encapsulation. However, at present, there is a phenomenon of P-layer (POE layer) additive migration in EPE, which is specifically manifested as follows: the P-layer additive migrates to the surface of the E-layer (EVA layer), resulting in insufficient cross-linking degree of the P layer, uneven local fluidity of the film, and stratification of the film as a whole after aging test. On the other hand, the problem is that since the P layer cannot be completely formed with high-melt-index POE particles, because the overall P layer fluidity is too high, there may be local overflow of glue, so a high- and low-melt-index compounding mode is used for film formation. However, after film formation, after the HF wet-freeze aging test, due to the different expansion coefficients of the E layer and the P layer, the P-layer additive will also migrate to the E layer, which may cause differences in the local expansion rate of the film, and also cause bubbles and stratification of the EPE film. In view of this, how to solve the above problems and improve the overall reliability of Topcon components has become the focus of current research in this field. Summary of the invention

[0004] In view of the shortcomings of the prior art, the object of the present invention is to provide an EPE encapsulation film and a preparation method and application thereof, in particular to provide a low-additive migration type Topcon double-glass EPE encapsulation film and a preparation method thereof. Compared with conventional EPE encapsulation films, the EPE encapsulation film provided by the present invention has a low P-layer additive migration rate, a more uniform overall film thickness, and no obvious bubbles or stratification after the wet-freeze test, that is, better wet-freeze resistance.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides an EPE encapsulation film, wherein the EPE encapsulation film comprises a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer stacked in sequence;

[0007] The raw materials for preparing the first EVA layer and the second EVA layer independently include the following components: EVA particles, a crosslinking agent, a co-crosslinking agent, a high-functionality acrylate, a tackifier, and a light stabilizer;

[0008] The raw materials for preparing the first POE layer and the third POE layer independently include the following components: high melt index POE particles, low melt index POE particles, a crosslinking agent, a co-crosslinking agent, a conventional acrylate, a tackifier, and a light stabilizer;

[0009] The raw materials for preparing the second POE layer include the following components: high melt index POE particles, a crosslinking agent, a co-crosslinking agent, a low-functionality acrylate, a tackifier, and a light stabilizer.

[0010] The EPE packaging film provided by the present invention has a five-layer structure, wherein the middle three layers are POE layers and the outermost layer is an EVA layer.

[0011] Among them, the second POE layer uses pure high melt index POE particles, which have better compatibility with additives after film formation. The use of low-functionality acrylates will also increase the compatibility of additives with POE particles. Therefore, the mobility of the additives is reduced after film formation, and the high melt index particles have good fluidity, which can make up for the problem of insufficient fluidity of high and low melt index composites after film formation. It is equivalent to the fluidity of the outermost conventional EVA particles, and can better wrap the high and low melt index composite film layers (i.e., the first POE layer and the third POE layer) evenly, so that the expansion coefficient of the overall film is in a coordinated state, and it will also make up for the deficiency that the cross-linking degree of the high and low melt index composite layers does not meet the requirements due to the excessively low amount of additives added.

[0012] The first POE layer and the third POE layer are compounded with high melt index POE particles and low melt index POE particles, which can reduce the amount of additives added, prevent the additives from migrating to the EVA film layer as much as possible, and relatively inhibit the migration of additives from the high melt index film layer (the second POE layer). If only pure high melt index POE particles are used to form the film, the overall film fluidity of the POE layer is too large, and glue overflow may occur during the lamination process. Therefore, the film of the first POE layer and the third POE layer can not only alleviate the migration of additives, but also adjust the overall fluidity of the POE layer;

[0013] Using EVA particles to form the film in the first and second EVA layers can reduce costs. Topcon uses double-glass encapsulation film. Since both sides are glass and there is no backplane, the reliability requirements for the module encapsulation film are lower than those for single-glass modules. If pure POE film is used, there is no cost advantage. Therefore, EVA particles are used to form the film to reduce costs, but low-functionality acrylates are used in some P layers. In order to ensure the overall film's anti-PID performance, high-functionality acrylates are added to the E layer.

[0014] That is, the EPE encapsulation film provided by the present invention includes a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer which are stacked in sequence, and the raw materials for preparing each layer are limited. The five-layer structure is synergistically compounded, so that the provided EPE encapsulation film has a low P-layer additive migration rate, a more uniform overall thickness of the film, and no obvious bubbles or stratification after the wet-freeze test, that is, the wet-freeze resistance performance is better.

[0015] Preferably, the raw materials for preparing the first EVA layer and the second EVA layer independently include the following components in parts by weight:

[0016]

[0017]

[0018] The raw materials for preparing the first POE layer and the third POE layer each independently include the following components in parts by weight:

[0019]

[0020] The raw materials for preparing the second POE layer include the following components in parts by weight:

[0021]

[0022] Preferably, the raw materials for preparing the first EVA layer and the second EVA layer are calculated by weight.

[0023] The amount of EVA particles is 100 parts;

[0024] The amount of the cross-linking agent can be 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc.;

[0025] The amount of the auxiliary cross-linking agent can be 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, etc.;

[0026] The amount of high-functionality acrylate can be 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, etc.;

[0027] The amount of the tackifier can be 0.05 part, 0.06 part, 0.08 part, 0.1 part, 0.12 part, 0.14 part, 0.15 part, 0.18 part, 0.2 part, etc.;

[0028] The amount of light stabilizer used can be 0.05 part, 0.06 part, 0.08 part, 0.1 part, 0.12 part, 0.14 part, 0.15 part, 0.18 part, 0.2 part, 0.22 part, 0.24 part, 0.25 part, 0.28 part, 0.3 part, etc.

[0029] Preferably, the raw materials for preparing the first POE layer and the third POE layer are calculated by weight.

[0030] Taking the dosage of high melt index POE particles and low melt index POE particles as 100 parts,

[0031] The amount of cross-linking agent can be 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, etc.;

[0032] The amount of the auxiliary cross-linking agent can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, etc.;

[0033] The dosage of conventional acrylate can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.;

[0034] The amount of the tackifier can be 0.05 part, 0.06 part, 0.08 part, 0.1 part, 0.12 part, 0.14 part, 0.15 part, 0.18 part, 0.2 part, etc.;

[0035] The amount of light stabilizer used can be 0.05 parts, 0.06 parts, 0.08 parts, 0.1 parts, 0.12 parts, 0.14 parts, 0.15 parts, 0.18 parts, 0.2 parts, etc.

[0036] Preferably, the raw materials for preparing the second POE layer are calculated by weight:

[0037] Taking the dosage of high melt index POE particles as 100 parts,

[0038] The amount of the cross-linking agent can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 1.1 parts, 1.2 parts, etc.;

[0039] The amount of the auxiliary cross-linking agent can be 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc.;

[0040] The amount of low-functionality acrylate can be 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc.;

[0041] The amount of tackifier can be 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.18, 0.2, etc.;

[0042] The amount of light stabilizer used can be 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.18, 0.2, etc.

[0043] Preferably, the melt index of the EVA particles at 125°C and 2.16kg is 20-31g / 10min, for example, 20g / 10min, 21g / 10min, 22g / 10min, 23g / 10min, 24g / 10min, 25g / 10min, 26g / 10min, 27g / 10min, 28g / 10min, 29g / 10min, 30g / 10min, 31g / 10min, etc.

[0044] Preferably, the high melt index POE particles have a melt index of 14-16 g / 10 min at 190° C. and 0.325 kg, such as 14 g / 10 min, 15 g / 10 min, 16 g / 10 min, etc.

[0045] Preferably, the low melt index POE particles have a melt index of 4-7 g / 10 min at 190° C. and 0.325 kg, such as 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, etc.

[0046] Preferably, in the first POE layer and the third POE layer, the mass ratio of high melt index POE particles to low melt index POE particles is (0.6-1.5):1, 0.6-1.5 can be, for example, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc.

[0047] Preferably, the crosslinking agent includes any one of tert-butyl peroxy-2-ethylhexyl carbonate, tert-amyl peroxy-2-ethylhexyl carbonate, methyl ethyl ketone peroxide, benzoyl peroxide, di-tert-butyl peroxide or diisopropylbenzene hydroperoxide, or a combination of at least two thereof.

[0048] Preferably, the auxiliary cross-linking agent includes any one of triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate or triethylene glycol methacrylate, or a combination of at least two thereof.

[0049] Preferably, the high-functionality acrylate comprises a tetrafunctional acrylate.

[0050] Preferably, the high-functionality acrylate includes any one of ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate or di(trimethylolpropane) tetraacrylate, or a combination of at least two thereof.

[0051] Preferably, the conventional acrylate comprises a trifunctional acrylate.

[0052] Preferably, the conventional acrylate includes any one of propoxy trimethylol triacrylate, trimethylol propane triacrylate, 3 (ethoxy) trimethylol propane triacrylate, (propoxy) glycerol triacrylate or pentaerythritol triacrylate, or a combination of at least two thereof.

[0053] Preferably, the low-functionality acrylate comprises a difunctional acrylate.

[0054] Preferably, the low-functionality acrylate includes any one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene glycol diacrylate or tripropylene glycol diacrylate, or a combination of at least two thereof.

[0055] Preferably, the adhesion promoter includes any one of γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, 3-(methacryloxy)propyltriethoxysilane, 3-(methacryloxy)propyltrimethoxysilane, vinyltrimethoxysilane or vinyltriethoxysilane, or a combination of at least two thereof.

[0056] Preferably, the light stabilizer includes any one or a combination of at least two of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinylethanol) succinate, bis-2,2,6,6-tetramethylpiperidinol sebacate, hindered amine light stabilizer, 1,3,5-trimethyl-2,4,6-tri(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(2,4-di-tert-butylphenyl) phosphite or 2,2,6,6-tetramethyl-4-piperidinyl ester.

[0057] Preferably, the thickness of the first EVA layer and the second EVA layer is independently 200-220 μm, for example, 200 μm, 203 μm, 205 μm, 208 μm, 210 μm, 213 μm, 215 μm, 218 μm, 220 μm, etc.

[0058] Preferably, the thickness of the first POE layer and the third POE layer is independently 60-70 μm, for example, 60 μm, 62 μm, 64 μm, 66 μm, 68 μm, 70 μm, etc.

[0059] Preferably, the thickness of the second POE layer is 70-80 μm, for example, 70 μm, 72 μm, 74 μm, 76 μm, 78 μm, 80 μm, etc.

[0060] In a second aspect, the present invention provides a method for preparing the EPE encapsulation film as described in the first aspect, the preparation method comprising the following steps:

[0061] The raw materials for preparing the first EVA layer, the first POE layer, the second POE layer, the third POE layer and the second EVA layer are mixed respectively, and then melt-coextruded to obtain the EPE packaging film.

[0062] In a third aspect, the present invention provides a use of the EPE encapsulation film as described in the first aspect in a photovoltaic module.

[0063] Compared with the prior art, the present invention has at least the following beneficial effects:

[0064] The EPE encapsulation film provided by the present invention comprises a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer which are stacked in sequence, and the raw materials for preparing each layer are limited. The five-layer structure is synergistically compounded, so that the EPE encapsulation film P layer has a low auxiliary agent migration rate, the overall thickness of the film is more uniform, and there are no obvious bubbles or stratification after the wet-freeze test, that is, the wet-freeze resistance performance is better. DETAILED DESCRIPTION

[0065] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0066] Example 1

[0067] In this embodiment, an EPE packaging film is provided, which includes a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer stacked in sequence, with thicknesses of 200 μm, 60 μm, 70 μm, 60 μm, and 200 μm, respectively.

[0068] The raw materials for preparing the first EVA layer and the second EVA layer include the following components in parts by weight:

[0069]

[0070]

[0071] The raw materials for preparing the first POE layer and the third POE layer include the following components in parts by weight:

[0072] raw material Specific components Weight Low melt index POE particles DOW PV 8660 40 High Melt Index POE Particles DOW PV 8669 60 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.4 Crosslinking agent Triallyl isocyanurate 0.5 Conventional acrylate Trimethylolpropoxy triacrylate 0.3 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.1 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.2

[0073] The raw materials for preparing the second POE layer include the following components in parts by weight:

[0074] raw material Specific components Weight High Melt Index POE Particles DOW PV 8669 100 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.8 Crosslinking agent Triallyl isocyanurate 0.7 Low functionality acrylate Dipropylene glycol diacrylate 0.8 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.1 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.2

[0075] The preparation method comprises the following steps: respectively mixing the preparation raw materials of the first EVA layer, the first POE layer, the second POE layer, the third POE layer and the second EVA layer, and then melt-coextruding to obtain the EPE packaging film.

[0076] Example 2

[0077] In this embodiment, an EPE packaging film is provided, which includes a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer stacked in sequence, with thicknesses of 200 μm, 60 μm, 70 μm, 60 μm, and 200 μm, respectively.

[0078] The raw materials for preparing the first EVA layer and the second EVA layer include the following components in parts by weight:

[0079]

[0080] The raw materials for preparing the first POE layer and the third POE layer include the following components in parts by weight:

[0081] raw material Specific components Weight Low melt index POE particles DOW PV 8660 50 High Melt Index POE Particles DOW PV 8669 50 Crosslinking agent tert-Amyl peroxy-2-ethylhexyl carbonate 0.3 Crosslinking agent Triallyl cyanurate 0.2 Conventional acrylate Pentaerythritol triacrylate 0.2 Tackifier γ-Methacryloyloxypropyltriethoxysilane 0.05 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.05

[0082] The raw materials for preparing the second POE layer include the following components in parts by weight:

[0083] raw material Specific components Weight High Melt Index POE Particles DOW PV 8669 100 Crosslinking agent tert-Amyl peroxy-2-ethylhexyl carbonate 0.5 Crosslinking agent Triallyl cyanurate 0.6 Low functionality acrylate 1,6-Hexanediol diacrylate 0.6 Tackifier γ-Methacryloyloxypropyltriethoxysilane 0.05 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.05

[0084] The preparation method is the same as Example 1.

[0085] Example 3

[0086] In this embodiment, an EPE packaging film is provided, which includes a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer stacked in sequence, with thicknesses of 200 μm, 60 μm, 70 μm, 60 μm, and 200 μm, respectively.

[0087] The raw materials for preparing the first EVA layer and the second EVA layer include the following components in parts by weight:

[0088] raw material Specific components Weight EVA particles Hanwha E282 PV 100 Crosslinking agent Methyl Ethyl Ketone Peroxide 1 Crosslinking agent Trimethylolpropane triacrylate 1 Highly functional acrylate Di(trimethylolpropane)tetraacrylate 1.5 Tackifier 3-(Methacryloyloxy)propyltriethoxysilane 0.1 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.3

[0089] The raw materials for preparing the first POE layer and the third POE layer include the following components in parts by weight:

[0090]

[0091] The raw materials for preparing the second POE layer include the following components in parts by weight:

[0092]

[0093]

[0094] The preparation method is the same as Example 1.

[0095] Example 4

[0096] In this embodiment, an EPE packaging film is provided, which includes a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer stacked in sequence, with thicknesses of 200 μm, 60 μm, 70 μm, 60 μm, and 200 μm, respectively.

[0097] The raw materials for preparing the first EVA layer and the second EVA layer include the following components in parts by weight:

[0098] raw material Specific components Weight EVA particles Hanwha E282 PV 100 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.8 Crosslinking agent Triallyl isocyanurate 0.8 Highly functional acrylate Ethoxylated pentaerythritol tetraacrylate 1.2 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.15 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.1

[0099] The raw materials for preparing the first POE layer and the third POE layer include the following components in parts by weight:

[0100]

[0101]

[0102] The raw materials for preparing the second POE layer include the following components in parts by weight:

[0103]

[0104] The preparation method is the same as Example 1.

[0105] Comparative Example 1

[0106] The difference between this comparative example and Example 1 is that the raw materials for preparing the second POE layer are different.

[0107] Specifically, the raw materials for preparing the second POE layer include the following components in parts by weight:

[0108] raw material Specific components Weight Low melt index POE particles DOW PV 8660 40 High Melt Index POE Particles DOW PV 8669 60 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.8 Crosslinking agent Triallyl isocyanurate 0.7 Low functionality acrylate Dipropylene glycol diacrylate 0.8 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.1 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.2

[0109] Comparative Example 2

[0110] The only difference between this comparative example and Example 1 is that the high-functionality acrylate in the raw materials for preparing the first EVA layer and the second EVA layer is replaced by an equal weight portion of conventional acrylate (specifically trimethylol propoxylate).

[0111] Comparative Example 3

[0112] In this comparative example, an EPE packaging film is provided. The EPE packaging film comprises a first EVA layer, a POE layer, and a second EVA layer which are stacked in sequence, and the thicknesses are 200 μm, 190 μm, and 200 μm, respectively.

[0113] The raw materials for preparing the first EVA layer and the second EVA layer include the following components in parts by weight:

[0114] raw material Specific components Weight EVA particles Hanwha E282 PV 100 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.7 Crosslinking agent Triallyl isocyanurate 0.6 Highly functional acrylate Ethoxylated pentaerythritol tetraacrylate 1 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.2 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.25

[0115] The raw materials for preparing the POE layer include the following components in parts by weight:

[0116] raw material Specific components Weight High Melt Index POE Particles DOW PV 8669 100 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.8 Crosslinking agent Triallyl isocyanurate 0.7 Low functionality acrylate Dipropylene glycol diacrylate 0.8 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.1 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.2

[0117] The preparation method comprises the following steps: respectively mixing the preparation raw materials of the first EVA layer, the POE layer and the second EVA layer, and then melt-coextruding them to obtain the EPE packaging film.

[0118] Comparative Example 4

[0119] In this comparative example, an EPE packaging film is provided. The EPE packaging film comprises a first EVA layer, a POE layer, and a second EVA layer which are stacked in sequence, and the thicknesses are 200 μm, 190 μm, and 200 μm, respectively.

[0120] The raw materials for preparing the first EVA layer and the second EVA layer include the following components in parts by weight:

[0121] raw material Specific components Weight EVA particles Hanwha E282 PV 100 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.7 Crosslinking agent Triallyl isocyanurate 0.6 Highly functional acrylate Ethoxylated pentaerythritol tetraacrylate 1 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.2 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.25

[0122] The raw materials for preparing the POE layer include the following components in parts by weight:

[0123] raw material Specific components Weight Low melt index POE particles DOW PV 8660 40 High Melt Index POE Particles DOW PV 8669 60 Crosslinking agent Tert-Butyl Peroxy-2-Ethylhexyl Carbonate 0.4 Crosslinking agent Triallyl isocyanurate 0.5 Conventional acrylate Trimethylolpropoxy triacrylate 0.3 Tackifier γ-Methacryloyloxypropyltrimethoxysilane 0.1 Light Stabilizer Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 0.2

[0124] The preparation method comprises the following steps: respectively mixing the preparation raw materials of the first EVA layer, the POE layer and the second EVA layer, and then melt-coextruding them to obtain the EPE packaging film.

[0125] The performance test of the EPE packaging film provided in the embodiment and the comparative example is carried out, and the test method is as follows:

[0126] (1) Vulcanization (MH): Tested in accordance with GB / T 16584-1996;

[0127] (2) Cross-linking degree: refer to Q / HZF001-2013 for sample preparation and testing;

[0128] (3) Overall extreme value of POE layer: Tested in accordance with JY / T 012-1996 General Rules for Metallographic Microscope Analysis Methods

[0129] (4) Humidity and frost resistance test: Tested in accordance with IEC 61215 and IEC 61730;

[0130] (5) Power attenuation: Tested in accordance with IEC 61215 and IEC 61730.

[0131] The performance test results are shown in Table 1 and Table 2.

[0132] Table 1

[0133]

[0134] It can be seen from Table 1 that the vulcanization and crosslinking degrees of the EPE encapsulation films provided by Examples 1-4 of the present invention have not been significantly reduced after being placed for 6 months, which indicates that the mobility of the additive in the P layer of the EPE encapsulation films provided by the present invention is low.

[0135] Although the EPE encapsulation film provided in Comparative Example 1 uses three POE layers, since the second POE layer also uses a compound of high melt index and low melt index POE particles, it shows vulcanization and reduced crosslinking degree after being placed for 2 months.

[0136] The EPE encapsulation film provided in Comparative Example 2 is different from that in Example 1 only in that the EVA layer is replaced with conventional acrylate. After 6 months of storage, its vulcanization and cross-linking degrees have not been significantly reduced, which indicates that acrylate does not affect the migration of the P layer additives. It needs to be determined whether it affects other properties.

[0137] The EPE encapsulation film provided in Comparative Example 3 has a three-layer structure, and the POE layer uses pure high melt index POE particles and low-functionality acrylates. However, since a high- and low-melt index composite POE layer is not provided, vulcanization and reduced crosslinking degree occur after being placed for 5 months.

[0138] The EPE encapsulation film provided in Comparative Example 4 showed reduced vulcanization and crosslinking degree after being placed for one month, and its auxiliary agent migration rate was high. This is because the EPE encapsulation film provided in Comparative Example 4 has only one POE layer and uses a compound of high melt index and low melt index POE particles.

[0139] Table 2

[0140]

[0141] It can be seen from Table 2 that the P layer of the EPE encapsulation film provided by Examples 1-4 of the present invention has a small overall range (15-19 μm), no bubbles appear after 10 HF test cycles, good humidity and frost resistance, and excellent anti-PID effect.

[0142] Although the EPE encapsulation film provided in Comparative Example 1 uses three POE layers, since the second POE layer also uses a compound of high melt index and low melt index POE particles, the overall range of the P layer increases, and bubbles appear after 10 HF test cycles.

[0143] Although the EPE encapsulation film provided in Comparative Example 2 uses three POE layers, because conventional acrylates are used in the preparation of the first and second EVA layers, the conventional acrylates have relatively low functionality, resulting in poor overall PID resistance of the encapsulation film. After PID192h, the power attenuation of the encapsulation film is too large.

[0144] The EPE encapsulation film provided in Comparative Example 3 has a three-layer structure, and the POE layer uses pure high melt index POE particles, which have excessive fluidity and result in uneven thickness during film extrusion. In addition, the POE layer of Comparative Example 3 uses low-functionality acrylate, which results in a significant deterioration in the overall anti-PID performance of the film.

[0145] The EPE encapsulation film provided in Comparative Example 4 has only one POE layer, and uses a compound of high melt index and low melt index POE particles. The POE layer film has uneven thickness locally, poor compatibility with the EVA layer, and different expansion coefficients, resulting in bubbles after 5 HF test cycles.

[0146] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the EPE encapsulation film and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An EPE packaging film, characterized in that: The EPE packaging film comprises a first EVA layer, a first POE layer, a second POE layer, a third POE layer, and a second EVA layer which are stacked in sequence; The raw materials for preparing the first EVA layer and the second EVA layer independently include the following components: EVA particles, a crosslinking agent, a co-crosslinking agent, a high-functionality acrylate, a tackifier, and a light stabilizer; The raw materials for preparing the first POE layer and the third POE layer independently include the following components: high melt index POE particles, low melt index POE particles, a crosslinking agent, a co-crosslinking agent, a conventional acrylate, a tackifier, and a light stabilizer; The raw materials for preparing the second POE layer include the following components: high melt index POE particles, a crosslinking agent, a co-crosslinking agent, a low-functionality acrylate, a tackifier, and a light stabilizer.

2. The EPE packaging film according to claim 1, characterized in that: The raw materials for preparing the first EVA layer and the second EVA layer each independently include the following components in parts by weight: The raw materials for preparing the first POE layer and the third POE layer each independently include the following components in parts by weight: The raw materials for preparing the second POE layer include the following components in parts by weight:

3. The EPE packaging film according to claim 1 or 2, characterized in that: The melt index of the EVA particles at 125°C and 2.16kg is 20-31g / 10min; Preferably, the high melt index POE particles have a melt index of 14-16 g / 10 min at 190° C. and 0.325 kg; Preferably, the low melt index POE particles have a melt index of 4-7 g / 10 min at 190° C. and 0.325 kg; Preferably, in the first POE layer and the third POE layer, the mass ratio of high melt index POE particles to low melt index POE particles is (0.6-1.5):

1.

4. The EPE packaging film according to any one of claims 1 to 3, characterized in that: The cross-linking agent includes any one of tert-butyl peroxy-2-ethylhexyl carbonate, tert-amyl peroxy-2-ethylhexyl carbonate, methyl ethyl ketone peroxide, benzoyl peroxide, di-tert-butyl peroxide or diisopropylbenzene hydroperoxide, or a combination of at least two thereof; Preferably, the auxiliary cross-linking agent includes any one of triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate or triethylene glycol methacrylate, or a combination of at least two thereof.

5. The EPE packaging film according to any one of claims 1 to 4, characterized in that: The high-functionality acrylate includes a tetrafunctional acrylate; Preferably, the high-functionality acrylate includes any one of ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate or di(trimethylolpropane) tetraacrylate, or a combination of at least two thereof.

6. The EPE packaging film according to any one of claims 1 to 5, characterized in that: The conventional acrylates include trifunctional acrylates; Preferably, the conventional acrylate includes any one of propoxy trimethylol triacrylate, trimethylol propane triacrylate, 3 (ethoxy) trimethylol propane triacrylate, (propoxy) glycerol triacrylate or pentaerythritol triacrylate, or a combination of at least two thereof.

7. The EPE packaging film according to any one of claims 1 to 6, characterized in that: The low-functionality acrylate includes a difunctional acrylate; Preferably, the low-functionality acrylate includes any one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene glycol diacrylate or tripropylene glycol diacrylate, or a combination of at least two thereof.

8. The EPE packaging film according to any one of claims 1 to 7, characterized in that: The tackifier includes any one of γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, 3-(methacryloxy)propyltriethoxysilane, 3-(methacryloxy)propyltrimethoxysilane, vinyltrimethoxysilane or vinyltriethoxysilane, or a combination of at least two thereof; Preferably, the light stabilizer includes any one or a combination of at least two of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinylethanol) succinate, bis-2,2,6,6-tetramethylpiperidinol sebacate, hindered amine light stabilizer, 1,3,5-trimethyl-2,4,6-tri(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(2,4-di-tert-butylphenyl) phosphite or 2,2,6,6-tetramethyl-4-piperidinyl ester.

9. A method for preparing an EPE encapsulation film as claimed in any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: The raw materials for preparing the first EVA layer, the first POE layer, the second POE layer, the third POE layer and the second EVA layer are mixed respectively, and then melt-coextruded to obtain the EPE packaging film.

10. Use of the EPE encapsulation film according to any one of claims 1 to 8 in a photovoltaic module.

Images