Internal bonding material for photovoltaic panel and flexible photovoltaic panel

Abstract

The invention relates to the technical field of photovoltaic panels, and discloses an internal bonding material for a photovoltaic panel and a flexible photovoltaic panel. The internal bonding material is used for the photovoltaic panel. The internal bonding material for the photovoltaic panel comprises polyester resin, fluorocarbon resin, a pigment filler, an aliphatic isocyanate curing agent, an organic tin catalyst, a force value auxiliary agent and an anti-aging delaminating auxiliary agent which are mixed according to the mass ratio of (50-75): (5-15): 15: 10: 0.6: (1-2): (2-3), the force value auxiliary agent is hydrogenated bisphenol A; the anti-aging delaminating auxiliary agent is epoxy modified castor oil. According to the internal bonding material for the photovoltaic panel, on the basis of the polyester resin, the fluorocarbon resin, the pigment filler, the curing agent and the catalyst in a certain mass ratio, the force value auxiliary agent (hydrogenated bisphenol A) and the anti-aging and delaminating auxiliary agent (epoxy modified castor oil) in a certain mass ratio are matched with the polyester resin, the fluorocarbon resin, the pigment filler, the curing agent and the catalyst in a certain mass ratio; the initial force value, the PCT24h aging force value and the PCT24h aging and yellowing resistance of the internal bonding material for the photovoltaic panel can be greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic panels, and in particular to an internal bonding material for photovoltaic panels and a flexible photovoltaic panel. Background Art

[0002] Traditional photovoltaic modules are formed by heating and laminating photovoltaic front glass plates, first packaging films (such as EVA films, POE films, etc.), photovoltaic cells, second packaging films, and photovoltaic back glass plates, which are stacked in order from top to bottom. Because such traditional photovoltaic modules use photovoltaic front glass plates and / or photovoltaic back glass plates, such photovoltaic modules do not have flexible bending characteristics and cannot be adapted to flexible photovoltaic modules.

[0003] With the rapid rise of distributed photovoltaic power stations, flexible photovoltaic modules have gradually gained market favor due to their strong adaptability and ability to fit various curved surfaces. Flexible photovoltaic modules need to be used with flexible photovoltaic panels (such as those shown in CN117799271A and CN111634074B) to replace traditional photovoltaic front glass panels and / or photovoltaic back glass panels.

[0004] The existing flexible photovoltaic panel, taking the composite photovoltaic backplane of CN111634074B as an example, includes a weather-resistant layer, a transparent supporting substrate layer, an adhesive layer and a functional layer; wherein the material of the adhesive layer includes a hydroxy polyester resin, a polar oligomer (such as polyvinyl alcohol), a first curing agent and a first water-absorbing filler; the material of the functional layer includes a polyolefin non-polar resin, a polar resin (such as polyvinyl alcohol) and a second water-absorbing filler. The adhesive layer has a good adhesive effect, which can ensure the interlayer adhesive performance inside the composite photovoltaic backplane; when the composite photovoltaic backplane is used in a photovoltaic module, one side of the functional layer is in contact with the encapsulation film, and the other side of the functional layer has a good adhesive effect with the adhesive layer, which can ensure the adhesive performance of the entire composite photovoltaic backplane and the encapsulation film. However, the existing composite photovoltaic backplane, whether its adhesive layer or its functional layer with adhesive effect, does not have good PCT aging resistance and PCT aging yellowing resistance, and it is difficult to adapt to harsh outdoor environments for a long time. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide an internal bonding material for a photovoltaic panel and a flexible photovoltaic panel.

[0006] Based on this, the present invention discloses an internal bonding material for a photovoltaic panel, which comprises raw materials mixed in the following mass ratio:

[0007] The mass ratio of polyester resin, fluorocarbon resin, pigment and filler, aliphatic isocyanate curing agent, organic tin catalyst, strength additive and anti-aging delamination additive is 50-75:5-15:15:10:0.6:1-2:2-3;

[0008] Wherein, the strength aid is hydrogenated bisphenol A; and the anti-aging delamination aid is epoxy-modified castor oil.

[0009] Preferably, in the internal adhesive material for photovoltaic panels of the present invention, the mass ratio of the polyester resin, fluorocarbon resin, pigment filler, curing agent, catalyst, strength aid and anti-aging delamination aid is 60-70:5-15:15:10:0.6:1-2:2-3.

[0010] Further preferably, in the internal adhesive material for a photovoltaic panel of the present invention, the mass ratio of the polyester resin to the fluorocarbon resin is 70:5.

[0011] Further preferably, in the internal adhesive material for a photovoltaic panel of the present invention, the mass proportion of the strength aid in the internal adhesive material for a photovoltaic panel is 1.83%.

[0012] Further preferably, in the internal adhesive material for a photovoltaic panel of the present invention, the weight proportion of the anti-aging delamination aid in the internal adhesive material for a photovoltaic panel is 2.74%.

[0013] Further preferably, the pigment filler is at least one of titanium dioxide pigment, insulating carbon black, copper chrome black inorganic pigment or high reflective black pigment;

[0014] The high-reflective black pigment is an organic perylene-based black pigment, anthraquinone pigment or phthalocyanine pigment (preferably an organic perylene-based black pigment).

[0015] More preferably, the catalyst is monobutyltin trichloride; and the aliphatic isocyanate curing agent is hexamethylene diisocyanate trimer (preferably Bayer N3390 curing agent).

[0016] Further preferably, the polyester resin is a hydroxyl-containing saturated polyester resin with a hydroxyl value of 50-80 mgKOH / g, such as Covestro 631, Covestro 650, Covestro 670 and other polyester resins.

[0017] Further preferably, the fluorocarbon resin is tetrafluoroethylene-vinyl liquid copolymer, such as Japan Daikin GK570.

[0018] The present invention also discloses a flexible photovoltaic panel, comprising a silicone protective layer, a fiber reinforcement layer and an inner bonding material layer for bonding a packaging film, which are laminated in sequence from the outside to the inside. The inner bonding material layer is formed by using the inner bonding material for photovoltaic panels described above in the present invention.

[0019] Preferably, the thickness of the inner adhesive material layer is 4-15 μm; preferably, the thickness of the inner adhesive material layer is 6-10 μm.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] The internal adhesive material for photovoltaic panels of the present invention is based on a certain mass ratio of polyester resin, fluorocarbon resin, pigment filler, curing agent and catalyst, and is further matched with a certain mass ratio of strength aid (hydrogenated bisphenol A) and anti-aging delamination aid (epoxy modified castor oil), which can greatly improve the initial strength, PCT24h aging strength and PCT24h aging yellowing resistance of the internal adhesive material for photovoltaic panels; therefore, the internal adhesive material for photovoltaic panels of the present invention can be better applied to flexible photovoltaic panels (especially flexible photovoltaic backplanes), so that the flexible photovoltaic panels can be used for a long time in harsh outdoor environments without aging stratification or aging yellowing, thereby further extending the life of flexible photovoltaic modules used in harsh outdoor environments for a long time.

[0022] Furthermore, the internal adhesive material for photovoltaic panels of the present invention appropriately increases the mass ratio of polyester resin to fluorocarbon resin, and appropriately increases the mass proportion of the strength aid (hydrogenated bisphenol A) and the aging-resistant delamination aid (epoxy-modified castor oil) in the internal adhesive material for photovoltaic panels; the internal adhesive material for photovoltaic panels not only maintains excellent PCT24h aging and yellowing resistance, but also helps to further improve its initial strength and PCT24h aging strength. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with specific implementation methods.

[0024] Example 1

[0025] The internal bonding material for photovoltaic panels of this embodiment includes: polyester resin (Covestro 650) with a mass ratio of 60:15:15:10:0.6:1:2, fluorocarbon resin (Daikin GK570), pigments and fillers, curing agents, catalysts, strength aids and anti-aging delamination aids.

[0026] Among them, the color filler uses highly reflective organic perylene black pigment (such as BASF L0086); the curing agent is Bayer N3390; the catalyst is monobutyltin trichloride, the strength aid is hydrogenated bisphenol A; and the anti-aging delamination aid is epoxy modified castor oil.

[0027] The method for preparing an internal adhesive material for a photovoltaic panel of the present embodiment is to uniformly mix the raw materials in the above mass ratio to obtain the internal adhesive material for a photovoltaic panel of the present embodiment.

[0028] A flexible photovoltaic panel of this embodiment includes a silicone protective layer, a fiber reinforcement layer, and an inner bonding material layer for bonding the packaging film, which are laminated from the outside to the inside; the material used in the inner bonding material layer is the inner bonding material for photovoltaic panels described above in this embodiment, and the thickness of the inner bonding material layer is 4-15μm (such as 6μm). The flexible photovoltaic panel of this embodiment can be used as a photovoltaic front panel and / or a photovoltaic back panel in a flexible photovoltaic module.

[0029] Example 2

[0030] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this embodiment are all referred to in Example 1, and the difference between them and Example 1 is that:

[0031] The pigment filler in the inner adhesive material for the photovoltaic panel of this embodiment is titanium dioxide pigment, and the mass ratio of the pigment filler is consistent with that of Example 1. At this time, the inner layer of the flexible photovoltaic panel of this embodiment is white.

[0032] Example 3

[0033] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this embodiment are all referred to in Example 1, and the difference between them and Example 1 is that:

[0034] The pigment filler in the inner adhesive material for the photovoltaic panel of this embodiment adopts copper chromium black inorganic pigment, and the mass ratio of the pigment filler is consistent with that of Example 1. At this time, the inner layer of the flexible photovoltaic panel of this embodiment is conventional black.

[0035] Example 4

[0036] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this embodiment are all referred to in Example 1, and the difference between them and Example 1 is that:

[0037] In the internal adhesive material for photovoltaic panels of this embodiment, the mass ratio of polyester resin, fluorocarbon resin, pigment filler, curing agent, catalyst, strength aid and anti-aging delamination aid is 70:5:15:10:0.6:1:2, and the types of the above raw materials are consistent with those in Example 1.

[0038] Example 5

[0039] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this embodiment are all referred to in Example 1, and the difference between them and Example 1 is that:

[0040] In the internal adhesive material for photovoltaic panels of this embodiment, the mass ratio of polyester resin, fluorocarbon resin, pigment filler, curing agent, catalyst, strength aid and anti-aging delamination aid is 60:15:15:10:0.6:1:3, and the types of the above raw materials are consistent with those in Example 1.

[0041] Example 6

[0042] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this embodiment are all referred to in Example 1, and the difference between them and Example 1 is that:

[0043] In the internal adhesive material for photovoltaic panels of this embodiment, the mass ratio of polyester resin, fluorocarbon resin, pigment filler, curing agent, catalyst, strength aid and anti-aging delamination aid is 60:15:15:10:0.6:2:2, and the types of the above raw materials are consistent with those in Example 1.

[0044] Comparative Example 1

[0045] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this comparative example are all referred to Example 2, and the difference between them and Example 2 is that:

[0046] In the internal adhesive material for photovoltaic panels of this comparative example, hydrogenated bisphenol A is not added, but is replaced by ethylene glycol with the same mass ratio as hydrogenated bisphenol A in Example 2.

[0047] Comparative Example 2

[0048] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this comparative example are all referred to Example 2, and the difference between them and Example 2 is that:

[0049] In the internal adhesive material for photovoltaic panels of this comparative example, the hydrogenated bisphenol A in Example 2 is replaced by bisphenol A of the same mass ratio.

[0050] Comparative Example 3

[0051] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this comparative example are all referred to Example 2, and the difference between them and Example 2 is that:

[0052] In the internal adhesive material for photovoltaic panels of this comparative example, the epoxy-modified castor oil in Example 2 is replaced by castor oil of the same mass ratio.

[0053] Comparative Example 4

[0054] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this comparative example are all referred to Example 2, and the difference between them and Example 2 is that:

[0055] In the internal adhesive material for the photovoltaic panel of this comparative example, hydrogenated bisphenol A is omitted.

[0056] Comparative Example 5

[0057] The internal bonding material for photovoltaic panels and the preparation method thereof and the flexible photovoltaic panel of this comparative example are all referred to Example 2, and the difference between them and Example 2 is that:

[0058] In the internal adhesive material for the photovoltaic panel of this comparative example, epoxy-modified castor oil is omitted.

[0059] Performance Testing

[0060] The performance tests were performed on the internal adhesive materials for photovoltaic panels of Examples 1-6 and Comparative Examples 1-5, and the test results are shown in Table 1 below.

[0061] 1. PCT 24h aging test (high voltage accelerated aging test) refers to the standard JESD 22-A102-C, the temperature is 121°C, the pressure is 205KPa, the humidity is 100%, and the test time is 24h.

[0062] 2. The force value test refers to the peel strength test method after the sheet and EVA film are laminated as specified in the standard GB / T 2790-1995. The sample size is 200mm long, 10±1mm wide, and the peeling speed is 100mm / min. The peel strength test method mainly adopts the 180° peeling test. This test method involves the use of an intelligent electronic tensile testing machine for testing. During the test, the sample needs to be clamped in the upper and lower chucks of the tensile testing machine respectively, and then a 180° peeling test is performed at a certain speed (such as 100mm / min). After the test is completed, the average force value of each sample is recorded and converted into a peel strength value (in Newtons / cm).

[0063] 3. The yellowing test complies with the standard GB / T39822-2021; the yellowness index (Δb) is used to characterize the degree of yellowing (yellowing) of colorless, transparent, translucent or nearly white polymer materials.

[0064] For the initial strength value, refer to the standard GB / T 2790-1995. For the PCT24h aging strength value, first refer to the standard JESD 22-A102-C for PCT24h aging treatment, and then refer to the standard GB / T 2790-1995 for strength test. For PCT24h aging yellowing, first refer to the standard JESD 22-A102-C for PCT24h aging treatment, and then refer to the standard GB / T39822-2021 for yellowing test.

[0065] Table 1

[0066] Example Initial force value (N / cm) PCT24h aging force value (N / cm) PCT24h aging yellowing (Δb) Example 1 132 77 0.23 Example 2 133 78 0.21 Example 3 135 80 0.24 Example 4 158 96 0.23 Example 5 136 120 0.24 Example 6 168 89 0.22 Comparative Example 1 68 52 0.26 Comparative Example 2 129 78 1.29 Comparative Example 3 130 39 0.31 Comparative Example 4 59 41 0.21 Comparative Example 5 120 Delamination 0.28

[0067] According to the data in Table 1, we can know that:

[0068] (1) The internal adhesive materials for photovoltaic panels of Examples 1-6 all have excellent initial strength value, PCT24h aging strength value and PCT24h aging yellowing resistance.

[0069] Compared with Example 1, if the mass ratio of polyester resin to fluorocarbon resin is appropriately increased (such as Example 4), or the mass proportion of the strength aid (hydrogenated bisphenol A) in the internal adhesive material for photovoltaic panels is appropriately increased (such as Example 6); then the internal adhesive material for photovoltaic panels can not only still maintain excellent PCT24h aging and yellowing resistance, but its initial strength and PCT24h aging strength will be significantly improved.

[0070] Compared with Example 1, if the mass proportion of the aging-resistant delamination aid (epoxy-modified castor oil) in the internal adhesive material for photovoltaic panels is appropriately increased (such as Example 5); then the internal adhesive material for photovoltaic panels can not only still maintain excellent PCT24h aging and yellowing resistance, the initial strength value of the internal adhesive material for photovoltaic panels will be slightly improved, and its PCT24h aging strength value will be greatly improved.

[0071] It can be seen that by appropriately increasing the mass ratio of polyester resin to fluorocarbon resin, and appropriately increasing the mass proportion of strength aid (hydrogenated bisphenol A) and aging-resistant delamination aid (epoxy-modified castor oil) in the internal adhesive material for photovoltaic panels, the internal adhesive material for photovoltaic panels of the present invention can not only still maintain excellent PCT24h aging and yellowing resistance, but also help to further improve the initial strength and PCT24h aging strength.

[0072] In addition, if the mass ratio of the hydroxyl-containing polyester resin to the fluorocarbon resin is too large, the weather resistance of the inner adhesive layer will be poor; if the mass ratio of the hydroxyl-containing polyester resin to the fluorocarbon resin is too small, it will easily lead to delamination between the inner adhesive layer and the fiber reinforcement layer and the packaging film. Too much strength aid (hydrogenated bisphenol A) will cause the inner adhesive layer to turn white, and the strength will not be further improved; too little hydrogenated bisphenol A will cause the strength between the inner adhesive layer and the packaging film to be insufficient and easy to delaminate. Too much anti-aging delamination aid (epoxy-modified castor oil) will increase the yellowing and there will be no significant improvement in the PCT24h aging strength; too little epoxy-modified castor oil may cause the PCT24h aging strength to be too low or delamination.

[0073] (2) Compared with Example 2, if hydrogenated bisphenol A is replaced with ethylene glycol of the same mass ratio (such as comparative example 1), the initial strength value, PCT24h aging strength value and PCT24h aging yellowing resistance of the internal adhesive material for photovoltaic panels will all decrease, especially the initial strength value and PCT24h aging strength value will decrease significantly; or, if hydrogenated bisphenol A is replaced with bisphenol A of the same mass ratio (such as comparative example 2), the PCT24h aging yellowing resistance of the internal adhesive material for photovoltaic panels will be greatly reduced, and its initial strength value will be reduced; or, if hydrogenated bisphenol A is omitted (such as comparative example 4), the initial strength value and PCT24h aging strength value of the internal adhesive material for photovoltaic panels will both be greatly reduced.

[0074] Moreover, compared with Example 2, if the epoxy-modified castor oil is replaced with castor oil of the same mass ratio (such as Comparative Example 3), the initial strength value, PCT24h aging strength value and PCT24h aging yellowing resistance of the internal adhesive material for photovoltaic panels will all decrease, especially the PCT24h aging strength value will decrease significantly; or, if the epoxy-modified castor oil is omitted (such as Comparative Example 5), the internal adhesive material for photovoltaic panels will directly delaminate, and its initial strength value and PCT24h aging yellowing resistance will both decrease.

[0075] It can be seen that the internal adhesive material for photovoltaic panels of the present invention (such as Example 2), based on a certain mass ratio of polyester resin, fluorocarbon resin, pigment filler, curing agent, and catalyst, is further combined with a certain mass ratio of strength aid (hydrogenated bisphenol A) and aging-resistant delamination aid (epoxy-modified castor oil), which can greatly improve the initial strength, PCT24h aging strength and PCT24h aging yellowing resistance of the internal adhesive material for photovoltaic panels.

[0076] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0077] The technical solution provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An internal bonding material for a photovoltaic panel, characterized in that: It includes raw materials mixed in the following mass ratio: The mass ratio of polyester resin, fluorocarbon resin, pigment and filler, aliphatic isocyanate curing agent, organic tin catalyst, strength additive and anti-aging delamination additive is 50-75:5-15:15:10:0.6:1-2:2-3; Wherein, the strength aid is hydrogenated bisphenol A; and the anti-aging delamination aid is epoxy-modified castor oil.

2. The internal bonding material for photovoltaic panels according to claim 1, characterized in that: The mass ratio of the polyester resin, fluorocarbon resin, pigment filler, curing agent, catalyst, strength additive and anti-aging delamination additive is 60-70:5-15:15:10:0.6:1-2:2-3.

3. The internal bonding material for photovoltaic panels according to claim 2, characterized in that: The mass ratio of the polyester resin to the fluorocarbon resin is 70:

5.

4. The internal bonding material for photovoltaic panels according to claim 2, characterized in that: The mass proportion of the strength additive in the internal adhesive material for photovoltaic panels is 1.83%.

5. The internal bonding material for photovoltaic panels according to claim 2, characterized in that: The anti-aging delamination aid accounts for 2.74% by mass in the internal adhesive material for photovoltaic panels.

6. An internal bonding material for photovoltaic panels according to claim 1 or 2, characterized in that: The pigment filler is at least one of titanium dioxide pigment, insulating carbon black, copper chrome black inorganic pigment or high reflective black pigment; The high-reflective black pigment is an organic perylene-based black pigment, anthraquinone pigment or phthalocyanine pigment.

7. An internal bonding material for photovoltaic panels according to claim 1 or 2, characterized in that: The catalyst is monobutyltin trichloride; and the aliphatic isocyanate curing agent is hexamethylene diisocyanate trimer.

8. The internal bonding material for photovoltaic panels according to claim 1 or 2, characterized in that: The polyester resin is a saturated polyester resin containing hydroxyl groups, and the hydroxyl value is 50-80 mgKOH / g.

9. An internal bonding material for photovoltaic panels according to claim 1 or 2, characterized in that: The fluorocarbon resin is a tetrafluoroethylene-vinyl liquid copolymer.

10. A flexible photovoltaic panel, comprising a silicone protective layer, a fiber reinforcement layer and an inner bonding material layer for bonding a packaging film, which are laminated in sequence from the outside to the inside, characterized in that: The inner adhesive material layer is formed by using the inner adhesive material for photovoltaic panels according to any one of claims 1 to 9; the thickness of the inner adhesive material layer is 4 to 15 μm.