White butyl rubber and photovoltaic module

Abstract

The invention belongs to the technical field of adhesives. The invention discloses white butyl rubber. The white butyl rubber comprises matrix resin and whitening filler, the matrix resin comprises butyl rubber and polyisobutene; the mass fraction of the whitening filler is 35-45%, and the whitening filler comprises a first whitening filler, a second whitening filler and a third whitening filler; the whiteness of the first whitening filler is greater than or equal to 95%; the whiteness of the second whitening filler is greater than or equal to 75%; the whiteness of the third whitening filler is greater than or equal to 90%; the mass ratio of the first whitening filler to the second whitening filler to the third whitening filler is (2-4): (0.5-1.5): (3-6); the Lab color values of the white butyl rubber are as follows: the L value is more than or equal to 90, the a value is less than or equal to 0 and the b value is less than or equal to 3. The white butyl rubber is high in whiteness and reflectivity, and the power generation efficiency of the battery can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of adhesives, and in particular relates to a white butyl adhesive and a photovoltaic module. Background Art

[0002] Butyl rubber has good water vapor barrier properties and is often used as a sealant to block water vapor. When butyl rubber is used in photovoltaic modules, it can improve the weather resistance of photovoltaic modules and increase the service life of solar cells.

[0003] However, in the process of implementing the technical solution of the embodiment of the present application, the applicant found that the above technology has at least the following technical problems:

[0004] The butyl rubber in the related art is usually black. When the butyl rubber is applied to photovoltaic modules, the black sealant will absorb sunlight, thus causing a waste of resources. By adding white fillers to the butyl rubber, the butyl rubber can be made white, but the whiteness of the white butyl rubber in the prior art is still low, and the reflectivity of light is poor, and it cannot make full use of sunlight. Summary of the invention

[0005] The embodiment of the present application provides a white butyl rubber, which has a high whiteness and can better reflect visible light and infrared light, thereby improving the power generation efficiency of the battery.

[0006] The embodiment of the present application provides a white butyl rubber, which includes a main resin and a whitening filler; the main resin includes butyl rubber and polyisobutylene; the mass fraction of the whitening filler is 35%-45%, and the whitening filler includes a first whitening filler, a second whitening filler and a third whitening filler; the whiteness of the first whitening filler is ≥95%; the whiteness of the second whitening filler is ≥75%; the whiteness of the third whitening filler is ≥90%; the mass ratio of the first whitening filler, the second whitening filler and the third whitening filler is (2-4):(0.5-1.5):(3-6); the Lab color value of the white butyl rubber is L value ≥90, a value ≤0, and b value ≤3.

[0007] Furthermore, the mass fraction of butyl rubber is 10%-30%, the mass fraction of polyisobutylene is 20%-30%; and the molecular weight of polyisobutylene is 50000-80000.

[0008] Furthermore, the particle size of the first whitening filler is 200-600nm, and the mass fraction of the first whitening filler is 10%-20%; the particle size of the second whitening filler is 20-100nm, and the mass fraction of the second whitening filler is 2%-5%; the particle size of the third whitening filler is 2-6μm, and the mass fraction of the third whitening filler is 13%-25%.

[0009] Furthermore, the oil absorption value of the first whitening filler is ≤28g / 100g, and the decolorizing power of the first whitening filler is ≥100%.

[0010] Furthermore, the first whitening filler includes titanium dioxide.

[0011] Furthermore, the specific surface area of ​​the second whitening filler is 175-225m 2 / g.

[0012] Further, the second whitening filler includes one or more of fumed silica and hexagonal boron nitride.

[0013] Furthermore, the static water adsorption of the third whitening filler is ≥ 23%.

[0014] Furthermore, the third whitening filler includes molecular sieve.

[0015] Furthermore, the white butyl rubber also includes other fillers in an amount of 5% to 20% by mass.

[0016] Furthermore, the other fillers include at least one of calcium carbonate, talc powder or mica powder.

[0017] Furthermore, the white butyl rubber also includes a tackifier in an amount of 5% to 10% by mass.

[0018] Further, the tackifier includes at least one of APAO resin, phenolic resin or terpene resin.

[0019] Furthermore, the white butyl rubber also includes 0.05%-0.3% by mass of an antioxidant and 0.05%-0.3% by mass of a light stabilizer.

[0020] Further, the antioxidant includes at least one of antioxidant 168, antioxidant 1076, antioxidant 1010, antioxidant 2246 or antioxidant 1520, and the light stabilizer includes at least one of light stabilizer 292, light stabilizer 622, light stabilizer 770 or light stabilizer 3529.

[0021] An embodiment of the present application also provides a photovoltaic module, which includes any of the above-mentioned white butyl rubber.

[0022] The white butyl rubber in the present application is selected by selecting whitening fillers with suitable whiteness and particle size, so that multiple whitening fillers cooperate with each other, which greatly improves the whiteness and light reflectivity of the white butyl rubber and improves the power generation efficiency of the battery. The white butyl rubber in the present application has a smaller color difference with the photovoltaic backsheet and is more beautiful. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation manner of the present application will be clearly and completely described below.

[0024] The embodiment of the present application provides a white butyl rubber, which includes a main resin and a whitening filler. The main resin includes butyl rubber and polyisobutylene. Butyl rubber has excellent insulation resistance, water resistance, ozone resistance and weather resistance, which can make the white butyl rubber have good reliability and service life. Polyisobutylene has touch stickiness and softness, which can improve the bonding performance of white butyl rubber. Polyisobutylene can also enhance the toughening of butyl rubber and improve the damping performance of butyl rubber. The whitening filler is used to improve the whiteness of white butyl rubber and improve the light reflection ability of white butyl rubber. When white butyl rubber is used in the photovoltaic field, the higher light reflection ability of white butyl rubber can reflect sunlight, so that this part of sunlight can be used again by the cells in the photovoltaic module, thereby improving the power generation efficiency of the photovoltaic module. The mass fraction of the whitening filler is 35%-45%. When the content of the whitening filler is too low, the whiteness of the white butyl rubber is low and the light reflection performance is poor. However, the amount of whitening filler should not be too high. The increase in the content of whitening filler will also reduce the water-blocking and weather-resistant properties of white butyl rubber. When the mass fraction of the whitening filler is 35%-45%, the whiteness of the white butyl rubber can be improved without reducing the water-blocking properties of the white butyl rubber. The whitening filler includes a first whitening filler, a second whitening filler and a third whitening filler. Since the whitening filler cannot be added in excess, the type of whitening filler is particularly important. The embodiment of the present application uses three different fillers to jointly improve the whiteness and light reflection performance of the white butyl rubber. The whiteness of the first whitening filler is greater than or equal to ≥95%, the whiteness of the second whitening filler is ≥75%, and the whiteness of the third whitening filler is ≥90%. The whiteness of the first whitening filler, the second whitening filler and the third whitening filler are all high, and have a good whitening effect. The mass ratio of the first whitening filler, the second whitening filler and the third whitening filler is (2-4):(0.5-1.5):(3-6). At this ratio, the whiteness of white butyl rubber is higher, and the color value is close to that of the photovoltaic backplane. The embodiment of the present application adds a variety of whitening fillers in a specific ratio, so that the whiteness and reflective performance of the white butyl rubber are better than that of a single white filler, and the Lab color value of the white butyl rubber can reach L value ≥ 90, a value ≤ 0, b value ≤ 3, with excellent whiteness. Through the synergistic effect of the first whitening filler, the second whitening filler and the third whitening filler, the reflectivity of the white butyl rubber in the visible light and infrared regions can reach more than 85%, which can better reflect light and improve the power generation efficiency of photovoltaic modules.

[0025] As an optional implementation, the mass fraction of butyl rubber is 10%-30%, and the mass fraction of polyisobutylene is 20%-30%. Butyl rubber and polyisobutylene are the main resins of white butyl rubber, which have good air tightness, vibration absorption and damping properties, and good electrical insulation. The molecular weight of polyisobutylene is 50,000-80,000. The saturation of polyisobutylene at this molecular weight is high, and it has good acid and alkali resistance, corrosion resistance, ozone resistance, UV aging resistance, excellent air tightness and electrical insulation, and excellent damping performance. Polyisobutylene can strengthen and toughen butyl rubber and improve the damping performance of butyl rubber.

[0026] As an optional embodiment, the particle size of the first whitening filler is 200-600nm, and the mass fraction of the first whitening filler is 10%-20%; the particle size of the second whitening filler is 20-100nm, and the mass fraction of the second whitening filler is 2%-5%; the particle size of the third whitening filler is 2-6μm, and the mass fraction of the third whitening filler is 13%-25%. The particle sizes of the first whitening filler, the second whitening filler and the third whitening filler are different. When mixed, the white filler with a smaller particle size can be filled into the gap between the white filler with a larger particle size, so that the mixture of the three fillers is more uniform and dense, so that the base color of butyl rubber and polyisobutylene can be better covered. The third whitening filler has a higher whiteness and a larger particle size, and the mass fraction can also be higher. The particle size of the first whitening filler is lower than that of the third whitening filler, and the whiteness is higher. Adding the first whitening filler can further improve the whiteness and hiding power of the white filler. The second whitening filler has the smallest particle size and can be fully filled into the gap between different fillers, thereby improving the density and hiding power of the white filler. The second whitening filler has a low whiteness, so it is not advisable to add too much of the second whitening filler.

[0027] As an optional embodiment, the oil absorption value of the first whitening filler is ≤28g / 100g, and the tinting power of the first whitening filler is ≥100%. The first whitening filler is the main whitening filler of white butyl rubber, and has a higher whiteness. The first whitening filler can make the white butyl rubber have a better whiteness. The particle size of the first whitening filler is 200-600nm. Under this particle size range, the scattering power of the first whitening filler is better and the whiteness is higher. The oil absorption value of the first whitening filler is ≤28g / 100g. Pigments with low oil absorption have a higher pigment volume concentration, which can give full play to the various optical properties of the first whitening filler. However, too high oil absorption is not conducive to the uniform dispersion of the filler in the resin system. The tinting power of the first whitening filler is ≥100%. The higher the tinting power of the pigment, the stronger the whitening ability of the pigment. The size of the tinting power is also related to the hiding power. The tinting power of the first whitening filler ≥100% can better cover the base color of the butyl rubber, so that the white butyl rubber presents a higher whiteness. The first whitening filler, as the main whitening filler, has a high decolorizing power and can better cover the base color of butyl rubber and polyisobutylene, making the hue of white butyl rubber white and having a high whiteness.

[0028] As an optional embodiment, the first whitening filler includes titanium dioxide. Titanium dioxide has a low oil absorption value and good tinting power, which can make the white butyl rubber have a higher whiteness and improve the reflectivity of the white butyl rubber to visible light and infrared light. Preferably, the titanium dioxide is rutile titanium dioxide. Compared with titanium dioxide with other crystal structures, the structure of rutile titanium dioxide is more stable, the atomic arrangement in the structure is more dense, and the scattering of light is also greater.

[0029] As an optional embodiment, the specific surface area of ​​the second whitening filler is 175-225m 2 / g. The second whitening filler is an auxiliary whitening filler. The second whitening filler has a small particle size, a larger specific surface area, and a higher surface activity, so it is easier to mix with other components. Due to its small particle size, the whiteness requirement of the second whitening filler can also be lower than that of the first whitening filler and the third whitening filler. Fillers with better other optical properties such as glossiness and scattering power but slightly lower whiteness can be selected. The particle size of the second whitening filler is 20-100nm. Within this particle size range, the scattering power of the second whitening filler is better, and it is more evenly mixed with other fillers. The mass fraction of the second whitening filler is 2%-5%. The second whitening filler can further improve the scattering power of white butyl rubber, and improve the hiding power and glossiness of the white filler. However, the amount of the second whitening filler should not be too high. Since the whiteness of the second whitening filler is lower than that of the first whitening filler, excessive addition of the second whitening filler will reduce the overall whiteness of the white butyl rubber.

[0030] As an optional embodiment, the second whitening filler includes fumed silica and hexagonal boron nitride. Fumed silica has a small particle size, a higher specific surface area, and good adsorption performance, and can improve the color uniformity of white butyl rubber. Fumed silica also has a certain reinforcing effect, which can improve the strength, ductility and wear resistance of white butyl rubber. Hexagonal boron nitride is preferably nano-flaky hexagonal boron nitride, which as a two-dimensional material has a layered structure similar to graphite and can be mixed into the butyl rubber system as a reinforcing phase to increase the mechanical strength and elastic modulus of the colloid; at the same time, it also has good chemical stability, has a better compatibility effect with each component in the butyl rubber system, and can further improve the corrosion resistance of the colloid.

[0031] As an optional embodiment, the particle size of the third whitening filler is 2-6 μm, and the mass fraction of the third whitening filler is 13%-25%. The third whitening filler is an auxiliary whitening filler. Since the third whitening filler has a higher whiteness, a material with a larger particle size can be selected, and the mass fraction can also be increased. The static water adsorption of the third whitening filler is ≥23%, and it has a good adsorption capacity, and it is easier to mix the first whitening filler and the second whitening filler.

[0032] As an optional embodiment, the third whitening filler includes molecular sieves. Molecular sieves have a large number of micropores, high surface activity, good adsorption performance, and better compatibility with other whitening fillers.

[0033] The three whitening fillers of the white butyl rubber in this application cooperate with each other, and three whitening fillers with different particle sizes, whiteness and other optical properties are added to the white butyl rubber in a specific ratio and mass fraction, so that the whitening fillers have better whiteness and hiding power. And the Lab color value of the white butyl rubber can reach L value ≥ 90, a value ≤ 0, b value ≤ 3, so that the color of the white butyl rubber is consistent with the color of the photovoltaic backboard, and has a better appearance. At the same time, the white backboard used for attachment usually has an L value ≥ 90, a value ≤ 0, and b value ≤ 3, which is basically consistent with the white butyl rubber provided in this application, and the color difference when the two are used in combination is smaller.

[0034] As an optional embodiment, the white butyl rubber further comprises other fillers with a mass fraction of 5%-20%. Preferably, the other fillers may include at least one of calcium carbonate, talcum powder or mica powder. Calcium carbonate is preferably activated calcium carbonate (such as Baiyanhua commonly used in the market). These fillers can both whiten the white butyl rubber and reinforce the white butyl rubber.

[0035] As an optional embodiment, the white butyl rubber also includes a tackifier with a mass fraction of 5%-10%. The tackifier can introduce active groups on the surface of the white butyl rubber to improve the surface energy of the white butyl rubber, significantly improve the adhesion performance of the white butyl rubber, so that the white butyl rubber can be closely combined with other materials, and improve the sealing, waterproofness and durability of the white butyl rubber. The tackifier can also cooperate with inorganic fillers such as molecular sieves to improve the water vapor barrier performance of the white butyl rubber. The mass fraction of the tackifier is 5%-10%. When the amount of the tackifier is too small, the adhesion performance of the white butyl rubber is poor, and the sealing effect and waterproofness will decrease. However, the amount of the tackifier should not be too much. The white butyl rubber with higher viscosity has poor fluidity and is difficult to produce and use. When the mass fraction of the tackifier is 5%-10%, the adhesion of the white butyl rubber is better, the reliability of the butyl rubber is higher and it is easy to produce and use. Preferably, the tackifier can include at least one of APAO resin, phenolic resin or terpene resin.

[0036] As an optional embodiment, the white butyl rubber further includes an antioxidant with a mass fraction of 0.05%-0.3%. The antioxidant can improve the antioxidant capacity of the white butyl rubber, making the white butyl rubber less likely to be oxidized and yellowed, and ensuring that the white butyl rubber can maintain a good whiteness during long-term use. Preferably, the antioxidant can include at least one of antioxidant 168, antioxidant 1076, antioxidant 1010, antioxidant 2246 or antioxidant 1520.

[0037] As an optional embodiment, the white butyl rubber further includes a light stabilizer with a mass fraction of 0.05%-0.3%. The light stabilizer can shield light, absorb and transfer light energy, quench or capture free radicals, reduce the possibility of photochemical reactions of the white butyl rubber, and delay the photoaging process of the white butyl rubber, thereby improving the UV resistance of the white butyl rubber, so that the whiteness of the white butyl rubber is still high after UV aging and does not turn yellow. Preferably, the light stabilizer includes at least one of light stabilizer 292, light stabilizer 622, light stabilizer 770 or light stabilizer 3529.

[0038] The embodiment of the present application also provides a photovoltaic module, which includes any of the above-mentioned white butyl rubber. Specifically, the white butyl rubber can be used for battery packaging, bonding and sealing of frames, and sealing of busbars and backplane cuts. The white butyl rubber in the present application has good water vapor barrier properties, which greatly improves the efficiency and service life of solar cells. The white butyl rubber in the present application has high reflectivity in the visible light and infrared regions. When light shines on the white butyl rubber, it can reflect excess sunlight to the battery cell and be used by the battery cell, thereby improving the power generation efficiency of the photovoltaic module.

[0039] The present application is further described below in conjunction with embodiments, but the protection scope of the present application is not limited to the embodiments.

[0040] The specific selection and source of each component are as follows:

[0041] Main resin:

[0042] Butyl rubber: Exxon 268S;

[0043] Polyisobutylene: BASF B12;

[0044] First whitening filler:

[0045] Rutile titanium dioxide: R-6668 from Shandong Jinhai Titanium Resources Technology Co., Ltd.

[0046] Second whitening filler:

[0047] Fumed silica: Cabot TS-720;

[0048] Hexagonal boron nitride: Xi'an Bona Material Technology Co., Ltd. BN-BN-001;

[0049] Third whitening filler:

[0050] Molecular sieve: 3A molecular sieve activated powder;

[0051] Other fillers:

[0052] Active calcium carbonate: XTCC201 from Shanxi Xintai Hengxin Nanomaterials Co., Ltd.; Talc: HF-1250A from Dashiqiao Wantong Powder Factory;

[0053] Tackifier:

[0054] APAO resin: Evonik APAO206;

[0055] Terpene resin: T-100.

[0056] The embodiments and comparative examples are provided according to Tables 1 to 5 below.

[0057] Table 1: Examples 1 to 4

[0058]

[0059]

[0060] Table 2: Examples 5 to 8

[0061]

[0062] Table 3: Examples 9 to 12

[0063]

[0064] Table 4: Examples 13-15

[0065]

[0066]

[0067] Table 5: Comparative Examples 1 to 5

[0068]

[0069]

[0070] The above embodiments and comparative examples were subjected to performance tests.

[0071] 1. Performance test:

[0072] 1. Water barrier performance: Use a water vapor transmission rate tester: Test according to the provisions of GB / T 21529-2008 "Determination of water vapor transmission rate of plastic films and sheets". Test conditions: temperature: (38±0.5)℃, relative humidity: (90±2)%. Test the water vapor transmission rate of butyl rubber at 38℃ and 1mm thickness [g / (m 2 ·day)].

[0073] 2. Color value: Use a spectrophotometer (Konica-Minolta CM-26d) with a 6500K color temperature light source. Under a 10° observation window, randomly select 5 locations on the surface of the test sample to measure the L*, a*, and b* values, and take the average value of the results.

[0074] 3. Color difference (butyl rubber and backboard): The color difference still uses the color value testing method to test the L*, a*, and b* values ​​of white butyl rubber and white backboard, and then calculates the difference △E between the two according to the formula △E=(△L^2+△a^2+△b^2)^0.5. The smaller the value, the closer the two colors are.

[0075] 4. Reflectivity: Using a spectrophotometer (Konika-Minota CM-26d), at a color temperature of 6500K and a 10° observation window, 5 locations were randomly selected on the surface of the test sample to measure the SCI reflectivity at a wavelength of 460nm, and the results were averaged.

[0076] 2. Performance test results:

[0077] The performance test results of the above embodiments and comparative examples are shown in Table 6.

[0078] Table 6: Test results

[0079]

[0080] From the performance data in the test results of Table 7, it can be seen that the white butyl rubber prepared in Examples 1 to 15 of the present application has good effects in blocking water vapor, increasing reflectivity, etc., has low water vapor permeability and high light reflectivity, can effectively block water vapor from penetrating into the interior of the photovoltaic module, and can also improve the utilization rate of sunlight and improve the power generation efficiency. At the same time, the white butyl rubber in Examples 1 to 15 has a stable color value, a small color difference with the backboard, and is more beautiful.

[0081] In Comparative Example 1, the content of whitening filler is low, the brightness of white butyl rubber is reduced, the emissivity is low, the color difference with the backboard is large, and the water vapor barrier performance is also poor. In Comparative Example 2, too much whitening filler is added, resulting in a decrease in the overall water vapor barrier performance. At the same time, although the color difference and reflectivity are improved to a certain extent compared with Comparative Example 1, it is still inferior to the white butyl rubber in Examples 1 to 15. In Comparative Examples 3 to 5, since only two whitening fillers are used, the fillers in the whitening fillers cannot work together to achieve the best effect. Therefore, compared with Examples 1 to 15, Comparative Examples 3 to 5 have a significant decrease in water vapor barrier performance, color difference and emissivity. Among them, since Comparative Examples 3 and Comparative Examples 5 do not use the first whitening filler or the third whitening filler with higher whiteness, there is a significant decrease in reflectivity, color difference and other properties. In Comparative Example 4, since the second whitening filler with lower whiteness is not used, the decrease in reflectivity, color difference and other properties is smaller than that in Comparative Examples 3 and 5.

[0082] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. A white butyl rubber, characterized in that: include: A main resin, wherein the main resin comprises butyl rubber and polyisobutylene; Whitening filler, the mass fraction of the whitening filler is 35%-45%, and the whitening filler includes a first whitening filler, a second whitening filler and a third whitening filler; The whiteness of the first whitening filler is ≥95%; The whiteness of the second whitening filler is ≥75%; The whiteness of the third whitening filler is ≥90%; The mass ratio of the first whitening filler, the second whitening filler and the third whitening filler is (2-4):(0.5-1.5):(3-6); The Lab color value of the white butyl rubber is L value ≥ 90, a value ≤ 0, and b value ≤ 3.

2. The white butyl rubber according to claim 1, characterized in that: The mass fraction of the butyl rubber is 10%-30%, the mass fraction of the polyisobutylene is 20%-30%; and the molecular weight of the polyisobutylene is 50000-80000.

3. The white butyl rubber according to claim 1, characterized in that: The particle size of the first whitening filler is 200-600 nm, and the mass fraction of the first whitening filler is 10%-20%; The particle size of the second whitening filler is 20-100 nm, and the mass fraction of the second whitening filler is 2%-5%; The particle size of the third whitening filler is 2-6 μm, and the mass fraction of the third whitening filler is 13%-25%.

4. The white butyl rubber according to claim 1, characterized in that: The oil absorption value of the first whitening filler is ≤28g / 100g, and the decolorizing power of the first whitening filler is ≥100%; the first whitening filler includes titanium dioxide.

5. The white butyl rubber according to claim 1, characterized in that: The specific surface area of ​​the second whitening filler is 175-225m 2 / g; The second whitening filler includes one or more of fumed silica and hexagonal boron nitride.

6. The white butyl rubber according to claim 1, characterized in that: The static water adsorption of the third whitening filler is ≥23%; The third whitening filler includes molecular sieve.

7. The white butyl rubber according to claim 1, characterized in that: The white butyl rubber also includes other fillers with a mass fraction of 5% to 20%; The other fillers include at least one of calcium carbonate, talc powder or mica powder.

8. The white butyl rubber according to claim 1, characterized in that: The white butyl rubber also includes a tackifier with a mass fraction of 5%-10%; The tackifier includes at least one of APAO resin, phenolic resin or terpene resin.

9. The white butyl rubber according to claim 1, characterized in that: The white butyl rubber further comprises an antioxidant with a mass fraction of 0.05% to 0.3% and a light stabilizer with a mass fraction of 0.05% to 0.3%; The antioxidant includes at least one of antioxidant 168, antioxidant 1076, antioxidant 1010, antioxidant 2246 or antioxidant 1520, and the light stabilizer includes at least one of light stabilizer 292, light stabilizer 622, light stabilizer 770 or light stabilizer 3529.

10. A photovoltaic module, characterized in that: The photovoltaic module comprises the white butyl rubber according to any one of claims 1 to 9.

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