CN113801584B

CN113801584B - Photovoltaic packaging adhesive film and photovoltaic module

Info

Publication number: CN113801584B
Application number: CN202111116309.3A
Authority: CN
Inventors: 魏梦娟; 许伟; 冯玉娟; 林建华
Original assignee: Foster Chuzhou New Material Co ltd
Current assignee: Foster Chuzhou New Material Co ltd
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2023-04-25
Anticipated expiration: 2041-09-23
Also published as: CN113801584A

Abstract

The invention belongs to the technical field of photovoltaics, and discloses a photovoltaic packaging adhesive film which is used for bonding a photovoltaic substrate and a battery piece together and comprises a POE layer prepared from polyolefin resin and auxiliary agents, an EVA layer arranged on one side of the POE layer and prepared from EVA resin raw materials and auxiliary agents, and a bonding layer arranged between the POE layer and the EVA layer and used for bonding the POE layer and the EVA layer together and blocking substance migration between the POE layer and the EVA layer, wherein the interlayer bonding force of the photovoltaic packaging adhesive film is not less than 50N/cm. The photovoltaic packaging adhesive film has the advantages of simple structure, low cost and excellent interlayer adhesion, and the auxiliary agent cannot be separated out from the surface and the interlayer of the adhesive film to influence the packaging of the component.

Description

Photovoltaic packaging adhesive film and photovoltaic module

Technical Field

The invention relates to the technical field of photovoltaics, in particular to a photovoltaic packaging adhesive film and a photovoltaic module.

Background

In recent years, energy and environmental problems are becoming more and more severe, clean energy is attracting attention, and solar cell modules are becoming more and more important. At present, an EVA or POE film is generally adopted for packaging the photovoltaic module, wherein the comprehensive performance of each aspect of POE is superior to that of EVA, but the cost is high, and the EVA and the POE are generally made into a co-extrusion adhesive film at present so as to reduce the cost.

The packaging performance of the co-extrusion adhesive film of EVA and POE is good, but because the co-extrusion adhesive film is combined by hot melting and does not have adhesive, the POE is nonpolar resin, the EVA resin is polar resin, the compatibility of the EVA resin and the polar resin is different, and the adhesive force between the aged layers can be reduced, so that the adhesive film inevitably generates layering after co-extrusion, the use of the packaging film is affected by internal easy delamination, and the reliability of the packaged photovoltaic module is reduced.

Therefore, an EVA/POE/EVA composite film with a siloxane auxiliary agent with a special polar structure added into a POE layer is proposed. During coextrusion, siloxane in the POE layer can migrate from the POE layer with low surface energy to the interface of the EVA layer with high surface energy and the POE layer, and the organic silicon polymer is formed by UV irradiation to bond the POE layer and the EVA layer. The interface bonding force of the composite film prepared in this way is high, and delamination phenomenon between layers in the adhesive film can be well avoided. However, this solution also has the serious disadvantage that the migration time of the siloxanes is not well controlled; the thickness of the formed organosilicon polymer is difficult to control; unreacted and complete siloxane auxiliary agent is easy to be chromatographed from POE, so that the surface of a glue film becomes slippery, the encapsulation of a component is further affected, and the performance of the glue film is affected by the defects.

Disclosure of Invention

In order to solve the technical problems, the applicant provides a photovoltaic packaging adhesive film which is excellent in interlayer adhesion, free of auxiliary agent precipitation and reliable in packaging performance.

The photovoltaic packaging adhesive film is used for bonding a photovoltaic substrate and a battery piece together and comprises the following components: POE layer, raw materials include polyolefin resin and first auxiliary agent, the thickness is 0.02-0.5 mm, preferably 0.2-0.3 mm; the EVA layer is arranged on one side of the POE layer, and the raw materials comprise EVA resin and a second auxiliary agent, and the thickness is 0.02-0.5 mm, preferably 0.2-0.3 mm; the bonding layer is arranged between the POE layer and the EVA layer and is used for bonding the POE layer and the EVA layer together and blocking substance migration between the POE layer and the EVA layer, and the raw materials comprise organic adhesive resin with the thickness of 0.02-0.3 mm; the interlayer cohesive force of the photovoltaic packaging adhesive film after sealed storage for one month at the temperature of 85 ℃ and the humidity of 85% is not less than 50N/cm.

Preferably, after the photovoltaic packaging adhesive film is stored for one month in a sealed mode at the temperature of 85 ℃ and the humidity of 85%, the migration amount of the first auxiliary agent in the POE layer is lower than 1500ppm.

Preferably, the first auxiliary agent comprises at least one of a cross-linking agent, an auxiliary cross-linking agent, an antioxidant, an ultraviolet light absorber, a light stabilizer, a tackifier or a pigment, the second auxiliary agent comprises at least one of a cross-linking agent, an auxiliary cross-linking agent, an antioxidant, an ultraviolet light absorber, a light stabilizer, a tackifier or a pigment, and the third auxiliary agent comprises at least one of a cross-linking agent, an auxiliary cross-linking agent, an antioxidant, an ultraviolet light absorber, a light stabilizer, a tackifier or a pigment.

Preferably, the organic adhesive resin includes at least one of epoxy resin, acrylate resin, silicone, polyimide, polybenzimidazole, and polyphenylquinoxaline.

Preferably, the polyolefin resin includes at least one of an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-octene copolymer, an ethylene-isobutylene copolymer, an ethylene-1-hexene copolymer, an ethylene-1-heptene copolymer, an ethylene-1-nonene copolymer, and an ethylene-1-decene copolymer.

Preferably, the preparation method of the photovoltaic packaging adhesive film comprises the following steps: preparing a photovoltaic packaging adhesive film comprising a POE layer, an EVA layer and a bonding layer through a three-layer coextrusion process; or preparing at least one layer of POE layer, EVA layer or adhesive layer by melt extrusion process, and preparing the residual coating by coating process to obtain the photovoltaic packaging adhesive film.

Preferably, the photovoltaic packaging adhesive film sequentially comprises a POE layer, an adhesive layer and an EVA layer.

Preferably, the preparation method of the photovoltaic packaging adhesive film comprises the following steps: preparing one layer of a POE layer, an EVA layer or a bonding layer through a melt extrusion process to prepare a first layer; and preparing a second layer and a third layer on the first layer through a coating process to obtain the photovoltaic packaging adhesive film which is sequentially arranged according to the POE layer, the bonding layer and the EVA layer.

Preferably, the first layer is a POE layer, then a bonding layer is prepared on one surface of the POE layer through a coating process, and an EVA layer is prepared on the other surface of the bonding layer through the coating process, so that the photovoltaic packaging adhesive film is prepared.

Preferably, the first layer is an adhesive layer, and then a POE layer is prepared on one surface of the adhesive layer through a coating process, and an EVA layer is prepared on the other surface of the adhesive layer through the coating process, so that the photovoltaic packaging adhesive film is prepared.

Preferably, a photovoltaic module for realizing photoelectric conversion converts light energy into electric energy, including photovoltaic substrate and battery piece, still include: the photovoltaic packaging adhesive film is used for bonding the photovoltaic substrate and the battery piece together and isolating the battery piece from the external environment;

the photovoltaic packaging adhesive film comprises: POE layer, raw materials include polyolefin resin, thickness is 0.02-0.5 mm, preferably 0.2-0.3 mm; the EVA layer is arranged on one side of the POE layer, and the raw materials comprise EVA resin with the thickness of 0.02-0.5 mm, preferably 0.2-0.3 mm; the bonding layer is arranged between the POE layer and the EVA layer and is used for bonding the POE layer and the EVA layer together, and the raw materials comprise organic adhesive resin with the thickness of 0.02-0.3 mm; the interlayer cohesive force of the photovoltaic packaging adhesive film after sealed storage for one month at the temperature of 85 ℃ and the humidity of 85% is not less than 50N/cm.

The invention has at least the following advantages:

1. the photovoltaic packaging adhesive film has excellent interlayer adhesion, and the internal adhesion is reliable and is not easy to delaminate.

2. The surface and interlayer of the photovoltaic packaging adhesive film are free from precipitation of an auxiliary agent, and the packaging material is stable in property and does not slip.

3. The photovoltaic packaging adhesive film has the advantages of simple structure, controllable quality in the production process, high reliability and low cost.

Drawings

FIG. 1 is a schematic cross-sectional view of a photovoltaic module according to the present invention;

FIG. 2 is a schematic cross-sectional view of a photovoltaic packaging film according to the present invention;

FIG. 3 is a schematic cross-sectional view of the photovoltaic module films of comparative examples 1 and 2;

FIG. 4 is a schematic cross-sectional view of the photovoltaic packaging film of comparative example 2 after UV irradiation;

FIG. 5 is a schematic cross-sectional view of the photovoltaic module film of comparative example 3;

FIG. 6 is a schematic cross-sectional view of the photovoltaic module film of comparative example 4;

in the figure: the photovoltaic module 100, the photovoltaic substrate 11, the photovoltaic packaging adhesive film 12, the battery piece 13, the POE layer 121, the bonding layer 122, the EVA layer 123 and the intermediate layer 124.

Detailed Description

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The present invention will be described in detail with reference to examples.

In order to enable those skilled in the art to better understand the present invention, the following description will make clear and complete descriptions of the technical solutions according to the embodiments of the present invention with reference to the accompanying drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the present invention, all the equipment and materials are commercially available or commonly used in the industry, and the methods in the examples described below are conventional in the art unless otherwise specified.

The photovoltaic packaging adhesive film 12 of the present invention is used for bonding the photovoltaic substrate 11 and the battery piece 13 together, as shown in fig. 1, and includes: POE layer 121, the raw materials include polyolefin resin, the thickness is 0.02-0.5 mm, preferably 0.2-0.3 mm; EVA layer 123, locate one side of POE layer 121, raw materials include EVA resin, thickness is 0.02-0.5 mm, preferably 0.2-0.3 mm; the bonding layer 122 is arranged between the POE layer 121 and the EVA layer 123, and is used for bonding the POE layer 121 and the EVA layer 123 together and blocking substance migration between the POE layer 121 and the EVA layer 123, and the raw materials comprise organic adhesive resin with the thickness of 0.02-0.3 mm; the POE layer raw material, the EVA layer raw material and the bonding layer raw material all further comprise an auxiliary agent, the POE layer raw material further comprises a first auxiliary agent, the EVA layer raw material further comprises a second auxiliary agent, and the bonding layer further comprises a third auxiliary agent; the interlayer cohesive force of the photovoltaic packaging adhesive film after sealed storage for one month at the temperature of 85 ℃ and the humidity of 85% is not less than 50N/cm, and the increment of the second auxiliary agent in the EVA layer is lower than 8000ppm. Further, after the photovoltaic packaging adhesive film is stored for one month in a sealed mode at the temperature of 85 ℃ and the humidity of 85%, the migration amount of the first auxiliary agent in the POE layer is lower than 3000ppm, and the increase amount of the second auxiliary agent in the EVA layer is lower than 8000ppm. Further, the increase of the second auxiliary agent in the EVA layer is less than 3000ppm; still further, the increase in the second adjuvant in the EVA layer is less than 1500ppm.

Wherein POE is a polyolefin thermoplastic elastomer material, has excellent toughness performance, good electrical insulation, excellent weather resistance, ultraviolet aging resistance, heat resistance, low temperature resistance, aging resistance, low water vapor transmittance, high cohesive force and high structural strength, and is a good packaging material. However, the raw materials are seriously monopolyed, the production technology is high, and the cost in actual production is too high, so that the raw materials are rarely used for producing the photovoltaic packaging adhesive film 12 independently.

EVA is ethylene vinyl acetate, belongs to a polar material, has high transparency, high adhesive force, easy storage at room temperature, good durability, good ultraviolet resistance, mature production technology and low cost, and is a packaging material commonly used in the field of photovoltaic packaging. However, EVA material steam is easy to permeate, acetic acid is easy to produce through hydrolysis, the strength is low, steam permeation can be caused in normal use, an adhesive film is atomized, the light transmittance is influenced, and the generated energy of the assembly is reduced.

The above problems can be well solved by making the POE and EVA material into a composite film, but the interlayer adhesion of the composite film thus made is unreliable, and the auxiliary agent of the POE layer 121 is easy to migrate into the EVA layer 122, thereby reducing the quality of the photovoltaic packaging film 12. Therefore, it is necessary to add the adhesive layer 122 between the POE layer 121 and the EVA layer 123, which can improve the adhesion between the POE layer 121 and the EVA layer 123, and can prevent the migration of the auxiliary agent in the POE layer 121 to the EVA layer 123, thereby improving the reliability of the photovoltaic packaging adhesive film 12.

The POE layer 121, the EVA layer 123 and the adhesive layer 122 all need to satisfy a certain thickness, the encapsulation effect of the photovoltaic encapsulation film 12 is reduced, the cost of the photovoltaic encapsulation film 12 is too high if the thickness is too thick, and the light transmittance of the photovoltaic encapsulation film 12 is also affected if the thickness is too high, so that the encapsulation effect of the photovoltaic encapsulation film 12 needs to be satisfied if the certain thickness is ensured.

As an implementation, POE layer 121 may be pre-crosslinked prior to use, with a degree of pre-crosslinking of 5-40%.

The POE layer 121 is pre-crosslinked mainly to reduce migration of the first auxiliary agent, enhancing reliability of the photovoltaic packaging film 12.

The bonding layer 122 is arranged between the POE layer 121 and the EVA layer 123, plays a role in migration of an auxiliary agent in the POE layer 121 to the EVA layer 123, and the bonding layer 122 needs to bond the POE layer 121 and the EVA layer 123 together, so that the bonding layer 122 needs to have enough bonding force for the POE layer and the EVA layer, and the bonding performance between the POE layer and the EVA layer is guaranteed.

As one implementation, the auxiliary agent includes at least one of a crosslinking agent, a co-crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a tackifier, or a pigment.

In order to improve the overall properties of the adhesive film, in a preferred embodiment, the adhesive film-forming raw material further comprises at least one of the group consisting of a crosslinking agent, a co-crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a tackifier and a pigment. Further, the raw materials for forming the resin composition further include 0.01 to 3 parts by weight of a crosslinking agent, 0.01 to 10 parts by weight of a secondary crosslinking agent, 0 to 0.4 part by weight of an ultraviolet light absorber, 0 to 0.5 part by weight of an antioxidant, 0 to 1.0 part by weight of a light stabilizer, 0 to 3.0 parts by weight of a tackifier, and 0 to 20 parts by weight of a pigment, relative to 100 parts by weight of the base resin.

The cross-linking agent is a molecule with a plurality of ethylenically unsaturated groups, which can promote the cross-linking of the polymer to achieve a higher degree of cross-linking. The cross-linking agent in the above composition may be selected from the types commonly used in the art, preferably, crosslinking agents include, but are not limited to, isopropyl t-butylperoxycarbonate, 2, 5-dimethyl-2, 5- (bis-t-butylperoxy) hexane, 2-ethylhexyl t-butylperoxycarbonate, 1-bis (t-butylperoxy) -3, 5-trimethylcyclohexane, 1-bis (t-amyl peroxy) cyclohexane at least one selected from the group consisting of 1, 1-bis (t-butylperoxy) cyclohexane, 2-bis (t-butylperoxy) butane, t-amyl peroxy-2-ethylhexyl carbonate, 2, 5-dimethyl-2, 5-bis (benzoylperoxy) -hexane, t-amyl peroxy carbonate, t-butyl peroxy-3, 5-trimethylhexanoate.

In a further implementation, the co-crosslinking agent includes, but is not limited to, at least one of triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ditrimethylolpropane tetraacrylate, propoxylated pentaerythritol tetraacrylate, 2,4, 6-tris (2-propenyloxy) -1,3, 5-triazine, tricyclic sunflower dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated bisphenol a dimethacrylate, 2-butyl-2-ethyl-1, 3-propanediol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate.

The antioxidant is used for improving the stability of the polymer in the extrusion processing process, the long-term and use process and delaying degradation caused by the action of hot oxygen. In a preferred embodiment, the antioxidant is a hindered phenol-based compound and/or a phosphite-based compound. Compared with other antioxidants, the antioxidant has better stability and oxidation resistance. More preferably, the hindered phenol based compound includes, but is not limited to, at least one of the group consisting of 2, 6-di-tert-butyl-4-ethylphenol, 2' -methylene-bis- (4-methyl-6-tert-butylphenol), 2' -methylene-bis- (4-ethyl-6-tert-butylphenol), 4' -butylene-bis- (3-methyl-6-tert-butylphenol), octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 7-octadecyl-3- (4 ' -hydroxy-3 ',5' -di-tert-butylphenyl) propionate, tetrakis- [ methylene-3- (3 ',5' -di-tert-butyl-4 ' -hydroxyphenyl) propionate ] methane; phosphite-based compounds include, but are not limited to, at least one of the group consisting of tris (2, 4-di-t-butylphenyl) phosphite, bis [2, 4-bis (1, 1-dimethylethyl) -6-methylphenyl ] ethyl phosphite, tetrakis (2, 4-di-t-butylphenyl) [1, 1-biphenyl ] -4,4' -diyl bisphosphite, and bis (2, 4-di-t-butylphenyl) pentaerythritol bisphosphite.

Ultraviolet light absorbers refer to substances that are capable of absorbing a substantial portion of ultraviolet energy and converting it to heat, thereby protecting certain electronic devices from ultraviolet light. In a preferred embodiment, the ultraviolet light absorber includes, but is not limited to, benzophenones and/or benzotriazoles, and more preferably, the ultraviolet light absorber includes, but is not limited to, at least one of the group consisting of 2-hydroxy-4-n-octoxybenzophenone, 2-tetramethylenebis (3, 1-benzoxazin-4-one), 2- (2 ' -hydroxy-5-methylphenyl) benzotriazole, and 2,2' -dihydroxy-4, 4' -dimethoxybenzophenone.

The light stabilizer is used for improving the stability of the packaging adhesive film under long-term ultraviolet irradiation. Preferably, the light stabilizer is a hindered amine-based compound. In a preferred embodiment of the present invention, light stabilizers include, but are not limited to, bis (2, 6-tetramethyl-4-piperidinyl) sebacate, bis (1-octyloxy-2, 6-tetramethyl-4-piperidinyl) sebacate graft copolymer obtained by polymerizing 4- (methyl) acryloyloxy-2, 6-tetramethyl piperidine and alpha-vinyl monomer 4- (meth) acryloyloxy-2, 6-tetramethylpiperidine graft copolymers obtained by polymerization with alpha-vinyl monomers.

The tackifier can improve the adhesive performance of the adhesive film. In a preferred embodiment, the adhesion promoter includes, but is not limited to, at least one of the group consisting of gamma-aminopropyl triethoxysilane, gamma-methacryloxypropyl trimethoxysilane, gamma- (2, 3-glycidoxy) propyl trimethoxysilane, vinyl trimethoxysilane, N- (beta-aminoethyl) -gamma-aminopropyl trimethoxysilane, gamma-glycidoxypropyl trimethylsilane, 3-aminopropyl trimethylsilane.

The pigment can be added to meet different application scenes according to the requirements of clients. In a preferred embodiment, the pigment includes, but is not limited to, a mixture of at least one of the following: at least one of the group consisting of calcium carbonate, barium sulfate, talc, titanium white, zinc oxide, carbon black, graphene oxide, copper chrome black, magnesium hydroxide, aluminum oxide, magnesium oxide, boron nitride, silicon carbide, ammonium phosphate, ammonium polyphosphate, pentaerythritol, dipentaerythritol ester, and melamine polyphosphate borate.

As one implementation, the organic adhesive resin includes at least one of epoxy resin, acrylate resin, silicone, polyimide, polybenzimidazole, and polyphenylquinoxaline.

The organic adhesive resin as a raw material of the adhesive layer 122 needs to have good adhesion to both the POE layer 121 and the EVA layer 123. The organic adhesive resins have excellent adhesion and can provide excellent adhesion to the adhesive layer 122.

The epoxy resin is a common organic adhesive resin, and has the advantages of simple bonding process, low cost, good bonding performance, high cohesive strength, high adhesive strength, small volume shrinkage and good dimensional stability. The epoxy resin has good performance and low cost, and can effectively reduce the production cost of the photovoltaic packaging adhesive film 12.

Acrylate resins are widely used as adhesives because of their strong hydrogen bonding properties. It can be solidified at room temp. and possesses a certain transparency, high strength, impact resistance, good weather resistance, and can be used for oil surface adhesion, and its application is convenient, impact resistance and shearing force are strong.

The organic silicon has the performances of inorganic materials and organic materials, has excellent cold and heat resistance, weather resistance, aging resistance and electrical insulation performance, has good cohesiveness, is also a high-elasticity body, and has good strain capacity.

Polyimide, polybenzimidazole and polyphenyl quinoxaline are high-temperature structural adhesives, and have high structural strength, good insulativity, cohesiveness and weather resistance, but are relatively expensive and high in cost.

As one implementation, the polyolefin resin includes at least one of an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-octene copolymer, an ethylene-isobutylene copolymer, an ethylene-1-hexene copolymer, an ethylene-1-heptene copolymer, an ethylene-1-nonene copolymer, and an ethylene-1-decene copolymer.

Preferably, the polyolefin resin has a melt flow index of 0.5 to 40g/10min and a light transmittance of 80% or more.

In another aspect, the present invention further provides a method for preparing the photovoltaic packaging adhesive film 12, which includes the following steps: the photovoltaic packaging adhesive film 12 including the POE layer 121, the EVA layer 123, and the adhesive layer 122 is prepared by a three-layer coextrusion process.

As one implementation, the photovoltaic packaging adhesive film 12 is manufactured by preparing at least one layer of the POE layer 121, the EVA layer 123 or the adhesive layer 122 through a melt extrusion process, and preparing the remaining coating through a coating process.

As one implementation, the photovoltaic packaging adhesive film 12 includes, in order, a POE layer 121, an adhesive layer 122, and an EVA layer 123.

The photovoltaic packaging adhesive film 12 has three preparation modes, namely, three layers of direct coextrusion is adopted to prepare the photovoltaic packaging adhesive film 12 which sequentially comprises a POE layer 121, a bonding layer 122 and an EVA layer 123; one is to co-extrude two adjacent layers of the three layers first and then coat the remaining layer on the adhesive layer 122 in a coating manner; in the last mode, two other layers are sequentially coated by taking one layer as a base layer, so that the photovoltaic packaging adhesive film 12 sequentially comprising the POE layer 121, the bonding layer 122 and the EVA layer 123 is obtained. The preparation method can be selected appropriately according to different raw materials of the photovoltaic packaging film.

The three-layer coextrusion process for preparing the photovoltaic packaging film 12 comprises the following specific steps:

the polyolefin resin and the auxiliary agent are uniformly mixed, the organic adhesive resin and the auxiliary agent are uniformly mixed, the EVA resin and the auxiliary agent are uniformly mixed, and the adhesive film with the three-layer structure comprising the POE layer 121, the bonding layer 122 and the EVA layer 123 is prepared by a three-layer coextrusion mode.

As an implementation manner, a method for preparing the photovoltaic packaging adhesive film 12 includes the following steps: preparing a co-extrusion film of the POE layer 121 and the bonding layer 122 through a melt extrusion process; and (3) preparing an EVA layer on the bonding layer 122 by a coating process to obtain the photovoltaic packaging adhesive film 12 which is sequentially arranged according to the POE layer 121, the bonding layer 122 and the EVA layer 123.

As an implementation manner, a method for preparing the photovoltaic packaging adhesive film 12 includes the following steps: preparing a co-extrusion film of the EVA layer 123 and the bonding layer 122 through a melt extrusion process; and (3) preparing a POE layer 121 on the bonding layer 122 through a coating process to obtain the photovoltaic packaging adhesive film 12 which is sequentially arranged according to the POE layer 121, the bonding layer 122 and the EVA layer 123.

As an implementation manner, a method for preparing the photovoltaic packaging adhesive film 12 includes the following steps: preparing one of a POE layer 121, an EVA layer 123 or a bonding layer 122 by a melt extrusion process to prepare a first layer; the second layer and the third layer were prepared on the first layer by a coating process to obtain the photovoltaic packaging adhesive film 12 arranged in sequence of the POE layer 121, the adhesive layer 122, and the EVA layer 123.

As an implementation manner, the first layer is the POE layer 121, the adhesive layer 122 is prepared on one surface of the POE layer 121 by a coating process, and the EVA layer 123 is prepared on the other surface of the adhesive layer 122 by a coating process, so as to obtain the photovoltaic packaging adhesive film 12.

As an implementation manner, the first layer is the adhesive layer 122, then the POE layer 121 is prepared on one surface of the adhesive layer 122 by a coating process, and the EVA layer 123 is prepared on the other surface of the adhesive layer 122 by a coating process, so as to obtain the photovoltaic packaging adhesive film 12.

As an implementation manner, the first layer is an EVA layer 123, then the adhesive layer 122 is prepared on one surface of the EVA layer 123 by a coating process, and the POE layer 121 is prepared on the other surface of the adhesive layer 122 by a coating process, so as to obtain the photovoltaic packaging adhesive film 12.

As an implementation manner, a photovoltaic module 100 for implementing photoelectric conversion to convert light energy into electric energy, including a photovoltaic substrate 11 and a battery piece 13, further includes: the photovoltaic packaging adhesive film 12 is used for bonding the photovoltaic substrate 11 and the battery piece 13 together and isolating the battery piece 13 from the external environment;

the photovoltaic packaging film 12 includes: POE layer 121, the raw materials include polyolefin resin, the thickness is 0.02-0.5 mm, preferably 0.2-0.3 mm; EVA layer 123, locate one side of POE layer 121, raw materials include EVA resin, thickness is 0.02-0.5 mm, preferably 0.2-0.3 mm; the bonding layer 122 is arranged between the POE layer 121 and the EVA layer 123, and is used for bonding the POE layer 121 and the EVA layer 123 together and blocking substance migration between the POE layer 121 and the EVA layer 123, and the raw materials comprise organic adhesive resin with the thickness of 0.02-0.3 mm; the interlayer adhesion of the photovoltaic packaging adhesive film 12 is not less than 50N/cm.

The invention will be further described by means of specific examples, but the invention is not limited to the examples given.

Example 1

As shown in fig. 1, a photovoltaic module 100 is composed of a photovoltaic substrate 11, a photovoltaic packaging adhesive film 12 and a battery piece 13.

As shown in fig. 2, the photovoltaic packaging adhesive film 12 is composed of a POE layer 121, an EVA layer 123 and an adhesive layer 122, wherein the POE layer 121 has a thickness of 0.3mm, the EVA layer 123 has a thickness of 0.3mm, and the adhesive layer 122 has a thickness of 0.3mm.

The POE layer 121 comprises 100 parts by weight of ethylene-1-butene copolymer, 3 parts by weight of tert-butyl isopropyl peroxycarbonate, 3 parts by weight of trimethylolpropane triacrylate, 0.4 part by weight of 2-hydroxy-4-n-octoxybenzophenone, 0.5 part by weight of 2,2' -methylene-bis- (4-methyl-6-tert-butylphenol) and 1 part by weight of bis (2, 6-tetramethyl-4-piperidinyl) sebacate, wherein the POE layer 121 is subjected to pre-crosslinking treatment, and the crosslinking degree is 5%;

EVA layer 123 raw materials comprise 100 weight parts of ethylene vinyl acetate, 2 weight parts of 1, 1-bis (tertiary butyl peroxy) -3, 5-trimethyl cyclohexane, 1 weight part of ethoxylated glycerol triacrylate, 0.2 weight part of 2, 2-tetramethylene bis (3, 1-benzoxazin-4-one), 0.3 weight part of octadecyl-3- (3, 5-di-tertiary butyl-4-hydroxyphenyl) propionate and 0.5 weight part of 4-hydroxy-2, 6-tetramethyl-1-piperidinol;

the raw materials of the adhesive layer 122 comprise 100 weight parts of organic silicon, 0.01 weight part of 1, 1-bis (tertiary butyl peroxy) cyclohexane, 0.01 weight part of triallyl cyanurate, 0.01 weight part of 2,2 '-dihydroxy-4, 4' -dimethoxy benzophenone, 0.01 weight part of pentaerythritol-tetra [3- (3, 5-di-tertiary butyl-4-hydroxy phenyl) propionate ], 0.01 weight part of 3, 5-di-tertiary butyl-4-hydroxy-hexadecyl benzoate and 3 weight parts of vinyl trimethoxy silane; the photovoltaic packaging adhesive film 12 is prepared by three-layer coextrusion.

Example 2

As shown in fig. 2, the photovoltaic packaging adhesive film 12 is composed of a POE layer 121, an EVA layer 123 and an adhesive layer 122, wherein the POE layer 121 has a thickness of 0.2mm, the EVA layer 123 has a thickness of 0.2mm, and the adhesive layer 122 has a thickness of 0.02mm.

The POE layer 121 comprises 100 parts by weight of ethylene-1-octene copolymer, 1.5 parts by weight of 1, 1-bis (tert-butyl peroxy) cyclohexane and 5 parts by weight of pentaerythritol tetraacrylate propoxylate, wherein the POE layer 121 is subjected to pre-crosslinking treatment, and the crosslinking degree is 40%;

EVA layer 123 raw materials comprise 100 weight parts of ethylene vinyl acetate, 0.1 weight part of tert-amyl peroxycarbonate, 0.5 weight part of ethoxylated bisphenol A dimethacrylate, 0.2 weight part of 2-hydroxy-4-n-octoxybenzophenone, 0.25 weight part of 7-octadecyl-3- (4 ' -hydroxy-3 ',5' -di-tert-butylphenyl) propionate, 0.5 weight part of graft copolymer obtained by polymerizing 4- (meth) acryloyloxy-2, 6-tetramethylpiperidine and alpha-vinyl monomer and 20 weight parts of dipentaerythritol ester;

the raw materials of the adhesive layer 122 comprise 100 parts by weight of epoxy resin, 3 parts by weight of tert-butyl peroxy 3, 5-trimethylhexanoate, 10 parts by weight of trimethylolpropane tetraacrylate, 0.05 part by weight of 2- (2' -hydroxy-5-methylphenyl) benzotriazole, 0.25 part by weight of tris (2, 4-di-tert-butylphenyl) phosphite, 0.1 part by weight of 4-hydroxy-2, 6-tetramethyl-1-piperidinol, 1.5 parts by weight of gamma- (2, 3-glycidoxy) propyltrimethoxysilane and 10 parts by weight of pentaerythritol;

the photovoltaic packaging film 12 is prepared by a coating method,

(1) Uniformly mixing 100 parts by weight of ethylene-1-octene copolymer and auxiliary agent, and melt-extruding POE layer 121;

(2) 100 parts by weight of epoxy resin and auxiliary agent are uniformly mixed at the outlet of an extrusion casting die head or after casting to form a film, and the film is arranged on the surface of a polyolefin layer in a doctor-blading mode to form a bonding layer 122;

(3) 100 parts by weight of ethylene vinyl acetate and an auxiliary agent were uniformly mixed and disposed on the surface of the adhesive layer 122 by spraying to form an EVA layer 123.

Example 3

As shown in fig. 2, the photovoltaic packaging adhesive film 12 is composed of a POE layer 121, an EVA layer 123 and an adhesive layer 122, wherein the POE layer 121 has a thickness of 0.25mm, the EVA layer 123 has a thickness of 0.2mm, and the adhesive layer 122 has a thickness of 0.1mm.

The POE layer 121 raw materials include 100 parts by weight of an ethylene-isobutylene copolymer, 0.01 parts by weight of 1, 1-bis (t-amyl peroxy) cyclohexane, 0.01 parts by weight of trimethylolpropane tetraacrylate, 0.1 parts by weight of 2,2' -dihydroxy-4, 4' -dimethoxybenzophenone, 0.1 parts by weight of 7-octadecyl-3- (4 ' -hydroxy-3 ',5' -di-t-butylphenyl) propionate and 0.1 parts by weight of 3, 5-di-t-butyl-4-hydroxy-hexadecyl benzoate, and the POE layer 121 is not subjected to a pre-crosslinking treatment;

EVA layer 123 raw materials comprise 100 weight parts of ethylene vinyl acetate, 0.5 weight parts of tert-amyl peroxy-2-ethylhexyl carbonate, 1 weight part of pentaerythritol triacrylate, 0.4 weight parts of 2, 2-tetramethylenebis (3, 1-benzoxazin-4-one), 0.5 weight parts of 2, 6-di-tert-butyl-4-ethylphenol and 0.5 weight parts of bis (1-octyloxy-2, 6-tetramethyl-4-piperidinyl) sebacate;

the raw materials of the bonding layer 122 comprise 100 parts by weight of acrylate resin, 0.5 part by weight of 1, 1-bis (tertiary amyl peroxy) cyclohexane, 0.5 part by weight of propoxylated pentaerythritol tetraacrylate and 3 parts by weight of N- (beta-aminoethyl) -gamma-aminopropyl trimethoxysilane;

the photovoltaic packaging film 12 is prepared by a coating method,

(1) Uniformly mixing 100 parts by weight of acrylate resin and an auxiliary agent, and performing melt extrusion to form a bonding layer 122;

(2) 100 parts by weight of polyolefin resin and auxiliary agent are uniformly mixed, 100 parts by weight of EVA resin and auxiliary agent are uniformly mixed, and the mixture is arranged on two sides of the bonding layer 122 in an inkjet printing mode to form a POE layer 121 and an EVA layer 123, so that the photovoltaic packaging adhesive film 12 with a three-layer adhesive film structure is formed.

Example 4

As shown in fig. 2, the photovoltaic packaging adhesive film 12 is composed of a POE layer 121, an EVA layer 123 and an adhesive layer 122, wherein the POE layer 121 has a thickness of 0.2mm, the EVA layer 123 has a thickness of 0.2mm, and the adhesive layer 122 has a thickness of 0.2mm.

The POE layer 121 comprises 100 parts by weight of ethylene-1-heptene copolymer, 3 parts by weight of tert-butyl peroxy 3,5 trimethylhexanoate, 5 parts by weight of trimethylolpropane trimethacrylate, 0.3 part by weight of 2-hydroxy-4-n-octoxybenzophenone, 0.3 part by weight of 2,2' -methylene-bis- (4-ethyl-6-tert-butylphenol) and 0.3 part by weight of tris (1, 2, 6-pentamethyl-4-piperidinyl) phosphite, and the POE layer is not subjected to pre-crosslinking treatment;

EVA layer 123 raw materials comprise 100 weight parts of ethylene vinyl acetate, 0.01 weight parts of tert-amyl peroxy-2-ethylhexyl carbonate, 0.01 weight parts of neopentyl glycol propoxylate diacrylate, 0.01 weight parts of 2-hydroxy-4-n-octoxybenzophenone, 0.01 weight parts of tetra- [ methylene-3- (3 ',5' -di-tert-butyl-4 ' -hydroxyphenyl) propionate ] methane and 0.01 weight parts of 3, 5-di-tert-butyl-4-hydroxy-benzoic acid hexadecyl ester;

the raw materials of the bonding layer 122 comprise 100 weight parts of organic silicon, 0.5 weight part of tert-amyl peroxycarbonate, 0.5 weight part of pentaerythritol tetraacrylate, 0.2 weight part of 2- (2 '-hydroxy-5-methylphenyl) benzotriazole, 0.2 weight part of tetra- [ methylene-3- (3', 5 '-di-tert-butyl-4' -hydroxyphenyl) propionate ] methane, 0.5 weight part of bis (1-octyloxy-2, 6-tetramethyl-4-piperidinyl) sebacate and 1 weight part of 3-aminopropyl trimethylsilane;

the photovoltaic packaging adhesive film is firstly prepared into an EVA layer 123 and an adhesive layer 122 double-layer adhesive film by a coextrusion mode, then a POE layer 121 is prepared on the adhesive layer 122 by a coating mode,

(1) Uniformly mixing 100 parts by weight of ethylene vinyl acetate and a related auxiliary agent 3, uniformly mixing organic silicon and a related auxiliary agent 2, and preparing a double-layer structure adhesive film of an EVA layer 123 and a bonding layer 122 in a coextrusion mode;

(2) The ethylene-1-heptene copolymer and the related auxiliary agent 1 are uniformly mixed and arranged on the surface of the bonding layer 122 in a screen printing mode to form the POE layer 121.

Example 5

Unlike example 1, the tie layer resin was polybenzimidazole.

Example 6

Unlike example 1, the EVA layer also includes 5 parts by weight of titanium pigment.

Comparative example 1

As shown in fig. 3, the photovoltaic packaging adhesive film 12 is composed of a POE layer 121 and an EVA layer 123, wherein the POE layer 121 has a thickness of 0.3mm, and the EVA layer 123 has a thickness of 0.3mm.

EVA layer 123 raw materials comprise 100 weight parts of ethylene vinyl acetate, 2 weight parts of 1, 1-bis (tertiary butyl peroxy) -3, 5-trimethyl cyclohexane, 1 weight part of ethoxylated glycerol triacrylate, 0.2 weight part of 2, 2-tetramethylene bis (3, 1-benzoxazin-4-one), 0.3 weight part of octadecyl-3- (3, 5-di-tertiary butyl-4-hydroxyphenyl) propionate and 0.5 weight part of 4-hydroxy-2, 6-tetramethyl-1-piperidinol; the photovoltaic packaging adhesive film 12 is prepared by a coextrusion mode.

Comparative example 2

The POE layer 121 comprises 100 parts by weight of ethylene-1-butene copolymer, 3 parts by weight of tert-butyl isopropyl peroxycarbonate, 3 parts by weight of trimethylolpropane triacrylate, 0.4 part by weight of 2-hydroxy-4-n-octoxybenzophenone, 0.5 part by weight of 2,2' -methylene-bis- (4-methyl-6-tert-butylphenol), 1 part by weight of bis (2, 6-tetramethyl-4-piperidinyl) sebacate and 5 parts by weight of siloxane containing a special polar structure, wherein the POE layer 121 is subjected to pre-crosslinking treatment, and the crosslinking degree is 5%;

EVA layer 123 raw materials comprise 100 weight parts of ethylene vinyl acetate, 2 weight parts of 1, 1-bis (tertiary butyl peroxy) -3, 5-trimethyl cyclohexane, 1 weight part of ethoxylated glycerol triacrylate, 0.2 weight part of 2, 2-tetramethylene bis (3, 1-benzoxazin-4-one), 0.3 weight part of octadecyl-3- (3, 5-di-tertiary butyl-4-hydroxyphenyl) propionate and 0.5 weight part of 4-hydroxy-2, 6-tetramethyl-1-piperidinol; the photovoltaic packaging film 12 is prepared by co-extrusion, and after co-extrusion, the siloxane is subjected to an addition reaction by UV irradiation to generate an organosilicon polymer, so that the thickness of the intermediate layer 124 is 0.01 (as shown in fig. 4).

Performance test and results

1. Performance test:

the photovoltaic packaging adhesive films 12 in the above examples 1 to 6 and the photovoltaic packaging adhesive films 12 in comparative examples 1 to 2 were subjected to performance test.

1. Transmittance:

and (3) light transmittance testing of the light-receiving surface side adhesive film: the packaging materials of examples 1 to 6 and comparative examples 1 to 2 were laminated, and then the films of each example and comparative example after lamination had a thickness of 0.45mm, and the transmittance was measured according to GB/T2410-2008, and the transmittance of the films of 700 to 400nm was measured by an ultraviolet-visible spectrophotometer.

2. Interlayer peel strength:

the glass/adhesive film (two layers)/flexible back plate with 300mm multiplied by 150mm are sequentially stacked and put into a vacuum laminating machine, and are pressed according to the laminating process for 18 minutes at 150 ℃ to manufacture the pressing piece.

The flexible back sheet/adhesive film was cut into 10 mm.+ -. 0.5mm samples every 5mm in the width direction for testing the adhesive force between the adhesive films. The film interlayer peeling force is tested on a tensile testing machine at a stretching speed of 100mm/min +/-10 mm/min, and the arithmetic average value of the three tests is taken to be accurate to 0.1N/cm.

3. Yellowing index:

taking a packaging adhesive film, placing a sample with a 'glass/packaging adhesive film/backboard' structure into an ultraviolet aging test box, and irradiating 120kWh/m with ultraviolet light ² And (5) sampling. And (3) testing the yellow index of the samples according to ASTME313-2010 before and after the experiment, wherein each sample is tested to be not less than 3 points, taking an average value, and taking the difference value of the yellow index before and after the ultraviolet accelerated aging test as a yellow index delta YI.

4. Component lamination appearance test

And packaging the solar cell module by using the packaging adhesive films obtained in the examples and the comparative examples according to the same process. Laminated according to the lamination sequence of glass/adhesive film/battery piece/adhesive film/glass, laminated according to the lamination process of the adhesion test, and manufactured into a standard double-glass solar battery module, wherein the module specification is a model of 60 (6 multiplied by 10) battery pieces (same manufacturer, same batch, same grade and size 156 mm). And manufacturing the assembly according to different adhesive films to evaluate the appearance. The evaluation criteria were evaluated for the occurrence of bubbles, impurities, delamination between the adhesive film and the battery sheet or glass, and were specifically as follows:

o: no delta: light x: severe.

5. Migration amount of auxiliary agent

The film samples were sealed in bottles and aged at a specific temperature and humidity (85 ℃ and RH 85%). After aging was complete, 3.000±0.001g of the pellet sample was weighed and placed into a 40mL vial. 14.5mL of acetonitrile was added to the vial, the vial was sealed, and shaken in a shaker for 5 minutes. The liquid in the 40mL vial was collected and placed in a 2mL sample vial for high pressure liquid chromatography ("HPLC") analysis. Samples were analyzed by HPLC according to the conditions in table 1 below:

TABLE 1 sample HPLC analysis conditions

The adjuvant content in the acetonitrile ("ACN") solution was calculated from a pre-established calibration curve. Calibration curves were established by plotting the UV absorbance response from the HPLC detector for acetonitrile solutions of certain adjuvants at five different concentration ranges from 2ppm to 500ppm using the conditions in the table above. The concentration of the sample adjuvant solution can then be determined from this pre-established curve. The migration level from the sample can be back calculated using the known content of the adjuvant in the sample solution. Values are given in ppm of the total weight of the sample.

2. Performance test results:

table 2: photovoltaic packaging adhesive film performance test meter

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In comparative example 1, no adhesive layer is formed by directly co-extrusion, the EVA layer and the POE layer are obtained from the data in the table, the transmittance of comparative example 1 is high, the yellowing index is small, but the peel strength between the layers of the photovoltaic packaging adhesive film is too low to be half of the value of the peel strength between any one of examples 1-6, the performance of the photovoltaic packaging adhesive film is affected by high migration of the auxiliary agent, and serious delamination exists between the EVA layer and the POE layer, so that the use requirement of the photovoltaic packaging adhesive film is not met.

Comparative example 2 in which siloxane having a specific polar structure was added to the POE layer, the interlayer peel strength of the photovoltaic packaging film obtained by co-extrusion of the EVA layer and the POE layer was improved as compared with comparative example 1, and the migration amount of the interlayer auxiliary agent was reduced, but the interlayer delamination phenomenon still occurred in comparative example 2 as compared with examples 1 to 6.

As can be seen from the data in the table, examples 1 to 6 have high light transmittance, less yellowing, high interlayer peeling strength, small interlayer auxiliary migration amount and no delamination between layers. Therefore, the photovoltaic packaging adhesive film provided by the invention has excellent interlayer adhesive force, no auxiliary agent is separated out from the interlayer, and the packaging performance is reliable.

It will be understood that modifications and variations will be apparent to those skilled in the art from the foregoing description, and it is intended that all such modifications and variations be included within the scope of the following claims.

Claims

1. A photovoltaic packaging adhesive film, comprising:

POE layer, raw materials include polyolefin resin and first auxiliary agent, thickness is 0.02-0.5 mm;

the EVA layer is arranged on one side of the POE layer, and the raw materials comprise EVA resin and a second auxiliary agent, and the thickness of the EVA layer is 0.02-0.5 mm;

the bonding layer is arranged between the POE layer and the EVA layer and is used for bonding the POE layer and the EVA layer together, and the raw materials comprise organic adhesive resin and a third auxiliary agent, and the thickness is 0.02-0.3 mm; the interlayer cohesive force of the photovoltaic packaging adhesive film after sealed storage for one month at the temperature of 85 ℃ and the humidity of 85% is not less than 50N/cm;

the organic adhesive resin comprises at least one of epoxy resin, acrylate resin, organosilicon, polyimide, polybenzimidazole or polyphenyl quinoxaline, and the polyolefin resin comprises at least one of ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-octene copolymer, ethylene-isobutene copolymer, ethylene-1-hexene copolymer, ethylene-1-heptene copolymer, ethylene-1-nonene copolymer or ethylene-1-decene copolymer.

2. The photovoltaic packaging film according to claim 1, wherein:

the thickness of the POE layer is 0.2-0.3 mm, and the thickness of the EVA layer is 0.2-0.3 mm; after the photovoltaic packaging adhesive film is stored for one month in a sealed mode at the temperature of 85 ℃ and the humidity of 85%, the migration amount of the first auxiliary agent in the POE layer is lower than 1500ppm.

3. The photovoltaic packaging film according to claim 1, wherein:

the first auxiliary agent comprises at least one of a cross-linking agent, an auxiliary cross-linking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a tackifier or a pigment, the second auxiliary agent comprises at least one of a cross-linking agent, an auxiliary cross-linking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a tackifier or a pigment, and the third auxiliary agent comprises at least one of a cross-linking agent, an auxiliary cross-linking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a tackifier or a pigment.

4. A method for preparing the photovoltaic packaging adhesive film according to any one of claims 1 to 3, comprising the steps of:

preparing a photovoltaic packaging adhesive film comprising a POE layer, an EVA layer and a bonding layer through a three-layer coextrusion process;

or alternatively, the first and second heat exchangers may be,

and preparing at least one layer of the POE layer, the EVA layer or the bonding layer through a melt extrusion process, and preparing a residual coating through a coating process to prepare the photovoltaic packaging adhesive film.

5. The preparation method of the photovoltaic packaging adhesive film as set forth in claim 4, which is characterized in that:

the photovoltaic packaging adhesive film sequentially comprises the POE layer, the bonding layer and the EVA layer.

6. The preparation method of the photovoltaic packaging adhesive film as set forth in claim 4, which is characterized by comprising the following steps:

preparing one layer of the POE layer, the EVA layer or the bonding layer through a melt extrusion process to prepare a first layer;

and preparing a second layer and a third layer on the first layer through a coating process to obtain the photovoltaic packaging adhesive film which is sequentially arranged according to the POE layer, the bonding layer and the EVA layer.

7. The method for preparing the photovoltaic packaging adhesive film according to claim 6, wherein the method comprises the following steps:

the first layer is the POE layer, then

The adhesive layer is prepared on one surface of the POE layer by a coating process,

and preparing the EVA layer on the other surface of the bonding layer through a coating process to prepare the photovoltaic packaging adhesive film.

8. The method for preparing the photovoltaic packaging adhesive film according to claim 6, wherein the method comprises the following steps:

the first layer is the bonding layer, then

The POE layer is prepared on one surface of the adhesive layer by a coating process,

9. A photovoltaic module for realize photoelectric conversion and convert light energy into electric energy, including photovoltaic base plate and battery piece, its characterized in that, photovoltaic module still includes:

the photovoltaic packaging adhesive film is used for bonding the photovoltaic substrate and the battery piece together and isolating the battery piece from the external environment;

the photovoltaic packaging adhesive film comprises the photovoltaic packaging adhesive film according to any one of claims 1 to 3 or the photovoltaic packaging adhesive film prepared by the preparation method of the photovoltaic packaging adhesive film according to any one of claims 4 to 8.